A number of years back, Danny Richie's GR Research system was voted as producing "Best Bass At The Show" by attendants of the RMAF show. Danny used a pair of Rythmik/GR Research OB/Dipole Subs at the front of the room, and a pair of Rythmik F12G Sealed Subs at the rear, their phase controls set 180 degrees opposed to the front subs.
Why the fascination with subwoofers?
I have noticed many posts with questions about adding subwoofers to an audio system. Why the fascination with subwoofers? I guess I understand why any audiophile would want to hear more tight bass in their audio system, but why add a subwoofer to an existing audio system when they don’t always perform well, are costly, and are difficult to integrate with the many varied speakers offered. Additionally, why wouldn’t any audiophile first choose a speaker with a well designed bass driver designed, engineered and BUILT INTO that same cabinet? If anyone’s speakers were not giving enough tight bass, why wouldn’t that person sell those speakers and buy a pair that does have tight bass?
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@noble100 wrote: "But my main reason for posting is to ask about your quote above. That’s what I meant to write. My understanding is that the idea is to arrange four subs in a centered, half-the wall’s-scale pattern on the front wall. So if the front wall is 18 feet wide by 8 feet tall, then the subs would be at the corners of a rectangle 9 feet wide by 4 feet tall, centered on the middle of the wall. This mimics the best four-sub geometry Todd Welt found in his study of symmetrical sub arrays, but it’s on the wall instead of on the floor. If the wall reflections cooperate, they should cancel out standing waves in the vertical and side-to-side dimensions. To cancel out standing waves in the front-to-back dimension, the idea is to use active cancellation based on an identical array on the rear wall. This array is in reverse polarity, with a time delay that corresponds to the length of the room. So the subs in the front of the room to create a planar wave that moves to the back of the room and then disappears as the active cancellation array cancels it when it gets to the back wall. The "no bass" you mentioned happens at the rear wall, not out in the room, or so the theory goes. I do not know how well this would work in practice. The answer is probably some variation on "it depends". Nor do I know whether it would sound better than a distributed multi-sub system. I haven’t really investigated it and will never build anything like it myself, but it MIGHT be a competitive "cost no object" approach. Duke |
rauliruegas: "Not for you but for other gentlemans this link could help to understand better the overall bass management: http://www.soundoctor.com/whitepapers/subs.htm " Hello rauliruegas, First I read anything from the doctor. I don't think the Sound Doctor is a good source of info for newbies. He goes on about bass standing waves, bass room modes, and bass sound wave timing as if he's not even aware of the scientific research and writings of Geddes, O'toole, Welti, Lejeune, etc. and that most of the in-room bass response issues he mentions can be solved through the use of a 4-sub distributed bass array system. I'm not sure if he's aware of the dba concept and how well it works or not. I wonder where the good Doctor got his degree from? Do you think he just bought one on the internet? It seems like he's the one in need of some bass management education. Tim |
Dear @rodman99999 : I own both Virgil Fox LP volume's ( if I remember: white vinyl. I don't listen it for several years now. ) and just great if you have the system that can showed. One recording with true subterrean bass range is the Dorian CD with the transcription scores of Pictures at an Exibition by Jean Guilllou. Always not only very good score quality performance but a true test for any system especially in the bass range. I own too an LP ( I can't remember the label. ) with the Mormom Tabernacle Choir that I remember wa really good recording. As a fact and as I posted there are " thousands " of recordings with true low bass range and with very good overall quality performance. Other labels that comes to my mind is Wilson Audio, Athena, Denon, Delos, Chalfont that along Cristal Clear several more are a must to listen it. Is just grandioso/magnificent that we truly can appreciated in all its grandiosity all those " historic "recordings. Good that some of us can do it. R. |
Dear @noble100 : """
I've learned that realistic reproduction of the majority of the bottom octave (16Hz–32Hz) doesn't require large woofers in large enclosures, 4 subs with 10" woofers """ well with the ones design you owns you phisically can't achieve that octave ( 16hz-32hz. ) but from 20hz up. A small driver as 10" with that " motor " can't do it at over 110 SPL and with low THD. Yes maybe some one could design a true sub with 10" woofers but this is other subject, yours can't do it. """ I'm not a Bass-Head but I admit ..... "", me neither. "" But I also believe in setting the crossover frequency as low as possible so the subs only engage when required for accuracy and not for an artificial general system bass boost. """ well in my case as low as 78hz. "" I've also discovered that bass quality is vastly more important than bass quantity. "" Always in agreement with but my main discovering using true self powered subs was the IMPACT that MUSIC we are listening makes when the IMD distortion kind goes way lower in the main speakers: mids/high ranges really shines with. As a very important side benefit is the quality level we accomplish in the overall system bass management. We have to remember that the MUSIC foundation and MUSIC frame belongs/lives in the bass frequency range and its quality levels. Not for you but for other gentlemans this link could help to understand better the overall bass management: http://www.soundoctor.com/whitepapers/subs.htm Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
audiokinesis: "Once we relax cost constraints, it might make more sense to build a planar array into the front wall and a corresponding array into the rear wall, reverse the polarity of the rear wall array, and time-delay it such that it cancels the signal from the front wall when it arrives." Hello Duke, I always enjoy your posts because I always seem to learn something. But my main reason for posting is to ask about your quote above. Was " and time-delay it such that it cancels the signal from the front wall when it arrives." accurate and not a typo? My rudimentary knowledge of bass room acoustics leads me to believe that equal bass sound waves from the front and rear would cause a standing wave room mode at the point that both waves meet, causing a bass cancellation resulting in a perception of no bass at all at that room location. Does the time delay or the polarity reversal on the rear planar array alter the dynamics? Please explain if you don’t mind. Thanks, Tim |
bdp24, Excellent description of bass , thank you. I often find it difficult to describe in words what I consider good bass response but I think your information about "critically damped" at a specific system Q factor of 0.7, wich is a good balance of bass quantity vs bass quality, is very descriptive and useful. Sort of like Goldilocks' porridge, just right. I understand that a sub's woofer driver has its own resonant Q, which is modified by the sub enclosure’s resonant Q. These resonances combine and interact to reach the system Q. A Q of less than 1 is considered overdamped, while a Q of more than 1 is underdamped. Most sub designers aim for a Q of about 0.7 to reach a compromise between extended bass response (down only 3dB at resonance) and good transient response (very slight overhang). Some designers maintain that a Q of 0.5 is ideal, and that a higher Q produces bass of poorer quality. I'm not sure of the exact Q factor of each of the Audio Kinesis Debra's 4 subs I use in my system, or if the Q factor of each sub differs from that of all 4 operating in concert. I expect the dba system Q factor would be somewhere in or very near the 0.5-0.7 range since I consider the bass performance to be very well balanced between bass quantity and quality. I think it’s possible to put together an extremely involving music system based on smaller speakers that don’t reproduce bass below about 50Hz. But I know I enjoy music and ht tremendously more with 6x2ft planar-magnetic panels and a 4-sub dba system that seamlessly integrates the high quality midrange/treble/imaging of the panels with the high quality bass of the dba that accurately extends the bass response down to 20 Hz. I've discovered that experiencing even just most of the bottom octave (16-32 Hz) on music and ht is immensely enjoyable mainly because I perceive both as more realistic. I'm not a Bass-Head but I admit I enjoy the bass weight and power that viscerally involves your whole body in the music or ht. But I also believe in setting the crossover frequency as low as possible so the subs only engage when required for accuracy and not for an artificial general system bass boost. I've also discovered that bass quality is vastly more important than bass quantity. A leaner presentation without much extension is preferable to me than lots of bass if that bass is thick, colored, and sluggish. If the bass isn’t well reproduced, I think most would agree we’d rather not hear it at all. The poor bass performance becomes a constant annoyance and a reminder that we’re listening to a reproduction. I've learned that realistic reproduction of the majority of the bottom octave (16Hz–32Hz) doesn't require large woofers in large enclosures, 4 subs with 10" woofers in relatively small enclosures are equally capable. It's also true that a system’s bass presentation affects such seemingly unrelated aspects of the sound as midrange clarity and sound staging. Thickness in the mid bass reduces the midrange’s transparency. A cleaner mid bass not only makes the midrange sound more open, it also lets you hear more clearly into the extremely low frequencies. Moreover, extending a system’s bottom end has the odd effect of increasing soundstage depth and our overall sense of the recorded acoustic, even on music with minimal low-frequency energy. I believe there are two main reasons to consider a subwoofer. The first is if you like the sound of your main speakers and just want more bass extension, power, and impact. The second is if you want a full-range sound but don’t want the intrusion of large, floor-standing speakers in your living room, although subs with floor-standing speakers can also definitely improve overall system bass response. Both cases sound simple in theory, but in practice, getting subs to blend with your main speakers is quite a challenge. Although you’ll undoubtedly get more bass, you might not achieve a sound that is seamless and coherent from bottom to top. That is, you might be aware that there’s big cones chugging away, seemingly disconnected from the rest of the music. But the 4 10" cones, chugging away at a more moderate pace and even with all in mono mode, of a dba's subs seem exceptionally well integrated with the rest of the music in my system. However, I'd suggest choosing subs designed for musical accuracy, not home-theater fireworks. Some subs exist to produce the highest possible sound-pressure-level at the lowest possible frequency for playing back explosions in film soundtracks. Others are crafted by musically sensitive designers with high-end sensibilities. Be sure which kind you prefer and are selecting. Proper placement of the subs is very important in providing optimum bass smoothness and detail. One of the huge advantages of sub/satellite systems is their ability to position the satellites for best imaging without worrying about the bass response, and then to locate the subs for best integration and bass response with the room and satellites. This includes treating full-range floor standers as satellites, too. It's critical to spend some time adjusting the subs’s or dba's amp controls so that it blends seamlessly with your main speakers. On the one hand, getting two different products (the main speakers and subs), designed by two different designers, to work together in harmony is asking a lot. On the other hand, you have much more control over subs or a dba system than you do over the bass output in a full-range system. Take advantage of the subs’s or dba amp's volume, phase, crossover frequency, and other adjustments to perfectly dial it into your system. Generally, the lower the crossover frequency between the subs and main speakers the better; the main loudspeaker’s bass is often of higher quality than the sub’s, and a low crossover frequency moves any crossover discontinuity lower in frequency, where it will be less audible. In addition, a low crossover frequency ensures that you won’t be able to locate the sound source of the low bass. Subs reproducing frequencies above 100Hz can be “localized”—i.e., the location of the source of the bass can be detected—which is musically distracting. Too low a crossover frequency will, however, burden small loudspeakers with excessive bass and reduce the system’s power handling and maximum listening level. Another variable in sub crossovers is the slope. Most use second-order (12dB/octave) or higher filters. Ideally, the crossover frequency and slope would be tailored to the particular loudspeakers used with the subs. But because the sub manufacturers don’t know which loudspeakers will be used with the subs, these parameters are compromised for good performance with a variety of loudspeakers. A sub’s or dba amp's phase control allows you to time-align the subwoofer’s wavefront with that of the main speakers. Here’s a simple trick for perfectly setting this adjustment. (This technique assumes that the phase control is a continuously variable knob, not just a simple “0/180°” switch.) Drive the system with a pure tone at exactly the crossover frequency between the subs and main speakers. (Many test CDs include a full range of test tones.) Driving the system with a pure tone at the crossover frequency causes the main loudspeakers and the subs to reproduce the same signal. Now invert the polarity of the main loudspeakers relative to the subs by reversing the red and black leads going to both loudspeakers. Sit in the listening chair and have an assistant slowly vary the phase control until you hear the least bass. Return the loudspeaker leads to their former (correct) polarity. The phase control is now set optimally. Here’s why: When the main loudspeakers’ and subs’s wavefronts are 180° out of phase with each other, the greatest cancellation (the least sound heard) will occur. That’s because as the subs’s cone moves outward, the main speakers’ cones are moving in, canceling each other. When the loudspeaker leads are returned to the correct position (removing the 180° phase shift), the subs and loudspeaker outputs are maximally in-phase. Any time lag between the main speakers and subs has been eliminated. This technique works because it’s much easier to hear the point of maximum cancellation than the point of maximum reinforcement. Most subs use either a sealed enclosure or a ported enclosure. Which type you choose will affect the character of the bass the sub produces. In a sealed enclosure, also called acoustic-suspension loading in some designs, the air inside the cabinet acts as a spring behind the woofer, compressing when the woofer moves in. In a ported enclosure, also called bass-reflex loading, the woofer’s rear wave is channeled outside the cabinet by a port or duct. Bass-reflex loaded system maintains flat bass response down to a lower frequency, but then the bass output drops off more quickly than it does in a sealed system. The common way of specifying a speaker’s low-frequency extension is to cite the frequency at which its response is attenuated by 3dB (“-3dB at 28Hz” for example). This method unfairly favors reflex loading because it doesn’t take into account the very steep roll-off below the -3dB cut-off frequency. The ideal method of specifying a loudspeaker’s bass extension is to cite the frequency in which its response is rolled off by 3dB as well as the frequency at which its response is rolled off by 10dB. A loudspeaker’s -10dB point is a more reliable indicator of a loudspeaker’s subjective bass fullness and extension because it takes into account not only the low-frequency cut-off point, but also the steepness of the roll-off. There’s one more technical difference between sealed and ported enclosures to know about- transient performance. A woofer in a sealed enclosure, when subject to a transient signal such as a kick drum, will tend to stop moving immediately after the transient. Conversely, a woofer in a vented enclosure could tend to keep moving after the drive signal has stopped. The speaker with the sealed enclosure generally has more accurate dynamic performance. The AK Debra dba system has removable port plugs that allow the choice of configuring them as either sealed/acoustic suspension or ported/bass-reflex subs. I've tried them in both configurations in my room/system and determined that I perceived both as equally dynamic on transients but preferred the ported configuration since the bass extension seemed superior. I have the crossover frequency on the sub amp set at 45 Hz, the volume set slightly under halfway and the phase control set in-phase at "0". My main Magnepan 2.7QRs are operated as full-range and I utilize no bass room treatments and no room correction, other than configuring my mains as 'Large' and my center and surrounds as 'Small' for ht. Sorry, I tend to err on the side of TMI on my posts, Tim |
Dear @audiokinesis : """ You can get good bass in one sweet spot with two equalized subs...""" and that’s the target of almost any audiophile at his room/system. Makes no sense to me to have several bass seat positions when the mids/hig frequency range has only one seat position and no one audiophile listen only bass range. I know is your business but not the one for a home audio system audiophiles. In my case at my place in my room and with my system I don’t need but 2 subs but as you posted: " you can get good bass in one sweet spot with two equalized subs "", that in my case are not equalized at all. Now I remember what you posted that +,- 3dbs at 100 and 20hz that I read at your site. Thank's. R. |
@rauliruegas wrote: "we not necessarily need 4 subs we can do it with two true subs. The Harman white papers proves that.... My target is to have the best solution ( rigth now with two true subs. ) at one and only one seat position where the mids and higs are spot on." You can get good bass in one sweet spot with two equalized subs. If you want good bass over a significantly larger area, four subs intelligently distributed can make a worthwhile improvement. (Note that Todd Welti et al did not investigate asymmetrical sub placements, and they also made the assumption that rooms are acoustically symmetrical at low frequencies. This totally made sense for the paper they were writing. But in practice rooms are never symmetrical low frequencies because unless the room has no doors or windows or AC vents or other "soft spots" in the room surfaces. Even a heavy recording studio door is a significant "soft spot", changing the room's effective length in that dimension at low frequencies.) Rauliruegas also said, "Btw, I take a look in your site and I don’t find out which are the 3 +,- db points in those 10" units. Could you share it?. Appreciated." The response of the individual Swarm units is the approximate inverse of "typical" room gain. "Typical room" gain has been given by several authors as being about 3 dB per octave below 100 Hz or so, so my response curve is -3 dB per octave from about 100 Hz down to about 20 Hz, and then below 20 Hz the rolloff accelerates rapidly. In other words I look at subs + room as a system, and my target is all about what the system does, not what the part I make does all by itself. The Swarm system is highly adjustable to work well with a wide variety of rooms. Ports can be plugged, polarities reversed and/or phase manipulated, and the amp includes a single band of parametric EQ along with a +3 dB "bass boost" switch. In practice, the output of the four distributed subs combines in semi-random phase at the upper end of the bass region, gradually transitioning to approach in-phase at the bottom end of the bass region as the wavelengths become long relative to the room dimensions. In most cases it is beneficial to offset this additional gain as we go down in frequency by reversing the polarity of one of the subs, or if we are using two amps, by manipulating the phase of one amp relative to the other. If I were to tell you that my subs are "-3 dB at such-and-such Hz", none of the above information would be conveyed by that spec. Unfortunately people compare subs based on who has the lowest -3 dB spec, and therefore manufacturers compete on the same basis, and what REALLY MATTERS (which is, what happens when you put the sub into a room) is not given much if any consideration. Duke |
Dear @audiokinesis : "" I didn’t design the Swarm to go below 20 Hz """ of course you did not and certainly not at your market price. I’m not with an attitude to make a critic or something against your product what I’m doing is to post some facts for the people really know where are " seated ". As you I have more than 25 years with the " fascination " subs ideas because is a true fascination when you are " there ". I’m a simple music lover and audiophile. The people that own your product could think they are " there " but in reality they are not yet. The true and complete room/system bass management premise is that the audio system can handled bass frequencies below 20hz at real/live event SPL with lower THD we can achieve in our room/system ( other day we can talk about the importance of that THD. ) and to accomplish that we need self powered true subwoofers and we not necessarily need 4 subs we can do it with two true subs. The Harman white papers proves that. Of course that if we are not satisfied with those two true subs in our room/system then we can go for the 4 solution. My target is to have the best solution ( rigth now with two true subs. ) at one and only one seat position where the mids and higs are spot on. There are alot of very valuable music information below 20hz in hundred/thousands of recordings and we can enjoy it in all its splendor if we have the system for reproduce it. The differences between a quasi-bass management against a true bass management is not little or tiny but higher that what any one of us can imagine. We have to experienced to understand it. Now all those gentlemans that already has the four not true subs only have to change it for true subs where maybe they will not needs 4 but only 2 but this depends of the room/system, which true subs were choosed and eacvh one of us targets. I understand the " fascination " that have your customers that are living with and they already think they discovery the bass " panacea " when it’s not that way. They are close to that panacea but needs to " work " to achieve it. So, my posts were not a true critic or something against to, not at all. Only facts. Btw, I take a look in your site and I don’t find out which are the 3 +,- db points in those 10" units. Could you share it?. Appreciated. Only for your records: I bougth my ADS L2030 ( that was not and stritly massive market product because was not designed for consummer market. ) many many years ago and when I was absolutely ig norant about bass management and its importance and with out knew nothing about the Harman papers. I bougth it in Laredo,Tx. because the vendor convince me about and because in those old times we can seen ADS advertasing in all audio magazynes as High Fidelity, Stereo Review or Audio. Well these sealed/acoustic suspension ADS design between other drivers has two 14" woofers and line source for the mids/higs and its bass specs at 3 +,- db are: 22hz and 18hz at 5+,- db an 16hz +,- 4 db bi-amp fashion using its dedicated active C2000 crossover that I owned and I think still own. Well, ADS was choosed ( with out knowing for my self any information about this.) by Telarc for monitoring all the Telarc recordings and the first recordings Telarc used ADS speakers designed exclusively for them and powered by Threshold. Latter on Telarc ask to ADS for a better full rage professional monitor and was then when ADS designed the L2030 that was runned in bi-amp fashion with the C2000 and Threshold electronics. The man behind the desin of ADS L2030 speakers was Mr.Kelly whom rigth after this his last ADS speaker design ( he was the engenner in chief in ADS. ) founded the very well regarded Aerial Acoustic that between other things has true subs in its catalog line. Well, even all those at some time of my audio life all was not enough for me and I started with subs till today where my self heavy up-graded L2030 works as satellite speakers in my room/system. I post this history because no matters how low the speakers goes if are passive design always will be a huge benefits integrating to those speakers with two true self powered subs. The subs market development and growing is just starting because from a few years now audiophiles are starting to learn that true subs are not for HT but for a stereo system in our places. So the best on regards is forth coming and this is a very good news for we audiophiles and people like you that are manufacturers and good designers. Good to know you and meet you here. Regards and enjoy the MUSIC NOPT DISTORTIONS, R. |
Hi @lewinskih01, you asked, "What is your point of view about time alignment of a SWARM or other DBA systems?" Imo time alignment is at best a secondary consideration in a distributed multi-sub system, from a perceptual standpoint. The ear has very poor time-domain resolution at low frequencies, and you are aware of Geddes’ thinking on the subject (which is based on AES papers). On the other hand the ear is very good at hearing loudness differences at low frequencies once the low frequencies become loud enough to be audible. This is why equal-loudness curves bunch up south of 100 Hz. A 5 dB difference at 40 Hz can be perceptually as big a difference as a 10 dB change at 1 kHz! The implication is that getting the in-room frequency response right matters more. Also, since speakers + room = a minimum phase system at low frequencies, when we fix the frequency domain we have also fixed the time domain, and vice-versa. That being said, imo you bring up something which intuitively makes sense: Preserving the initial pulse of bass energy, that which "whaps" you. It would seem that precise alignment of the arrival of the energy from multiple subs would best support that initial impulse, but how precise is "precise"? Within 1/4 wavelength? According to a paper I read, the ear cannot even detect the presence of bass energy from less than one wavelength, so the "precision" required might not be as great as our intuition would lead us to believe. This is just anecdotal, but every time I have reversed the polarity of one of the four subs in a Swarm system, there as been a subjective improvement, despite the fact that the initial pulse has been obviously degraded. This past October at RMAF an industry veteran manufacturer with decades of experience came into our room and played his reference recording of Fanfare for the Common Man. He said, "that’s what a tympani sounds like." He went on to say that our system (in a normal hotel room) did the best he had yet heard on that recording. We were using two amps and had manipulated the phase of the two left-side subs relative to the two right-side subs. Now it is theoretically possible to use four time-aligned and equalized channels of amplification and achieve precise time alignment and excellent in-room response smoothness simultaneously, and this would probably be even better. But at the price point I’m working, focusing on room-interaction related issues seems to give good return on investment. Once we relax cost constraints, it might make more sense to build a planar array into the front wall and a corresponding array into the rear wall, reverse the polarity of the rear wall array, and time-delay it such that it cancels the signal from the front wall when it arrives. Duke |
Dear @atmasphere: The main thread subject is about bass management, so I will answer to you on the tigth regards for last time: I'm not speculating nothing, I never do. I was very clear that we have ( is a must to. ) to have several experiences in different venues and with different kind of MUSIC in live events seated at near field position and it's from here from came my " speculations ". Rodman, bdp and noble explained very well. Period about. R. |
@audiokinesis Duke, great to see you join! Would like to ask your point of view about time alignment for subs. I run an active system with digital crossovers, time alignment, room correction. I currently have two sealed 12" Rythmiks playing summed up mono and planning to add one or two more to get a distributed bass array. Time alignment is of great value and active systems are ideal for this. But when it comes to a distributed bass array the sound is arriving at the mic from 3 or 4 different locations so difficult to identify "the max" in the pulse. At the same time Earl Geddes (who also proposes 3 or 4 subs in DBA) and others say we can only hear those frequencies after several cycles have played, so the pulse behavior might not be a good indicator. What is your point of view about time alignment of a SWARM or other DBA systems? Regards |
@rauliruegas wrote, about the AudioKinesis Swarm: "For a 10" woofer (as the four subs array posted here. ) is almost imposible to handled frequencies below 20hz at over 100dbs ( SPL. ) and with low THD kind of distortion." I didn’t design the Swarm to go below 20 Hz, but several customers who have measured the in-room response report -3 dB in the upper teens. For deepest loudest bass at the same price point (three grand for the system), a single monster sub is the way to go. I have designed a Swarm that can do well over 120 dB at 13 Hz, but it’s not very practical and I don’t think there would be much market for it. Each individual 10" Swarm unit can do about 100 dB at 20 Hz in-room at one meter without approaching x-max or amplifier clipping, assuming "typical" boundary reinforcement. I don’t know what the THD number would be, as imo that’s not a problem that needs solving. The in-room frequency response is of vastly greater audible consequence as long as neither woofer nor amp is driven beyond its linear limits. * * * * My fascination with subs dates back about twenty-five years, to my simultaneous fascination with Quads and music with bass. Duke |
@rodman99999 used the term "tight" in regard to a subject near and dear to my heart, that of musical cohesion within the rhythm section of a band. That is one of the foremost criteria in assessing the quality of that section, and his use of the term tight in this instance was in regard to musical tightness, not bass tightness in a purely audio sense. However, the bass quality of a woofer or subwoofer can and does also effect the perceived "tightness" of a rhythm section. One point about Ralph’s argument regarding bass tightness can be discussed in the terms speaker designers use: a woofer can be critically damped (0.7), over-damped (a lower number), or under-damped (a higher number). A designer who wants to get more perceived bass out of his speaker will under-damp it---at the cost of bass "looseness", while a designer who intends for his loudspeaker to be paired with a subwoofer may over-damp his speaker, knowing that the bass quantity sacrificed to achieve a higher bass quality will be compensated for by the sub. An over-damped woofer may not reproduce all the timbre, tone, and resonance produced by a, say, upright bass, as the over-damping will mute those qualities. An under-damped one may produce lots of bass quantity, but it’s lack of bass quality may result in the loss of the touch and timing of the bass player (and the drummer's playing of his bass drum). That’s why the best speaker designers aim for the critically damped figure of 0.7, the optimum compromise. |
@rauliruegas When I make comments regarding the sound or effectiveness of a thing in audio, if they are subjective in nature I use recordings that I made since I was there at the recording session and know how they are supposed to sound. I had the recordings produced on LP and CD. It is the nature of this sort of thing that only I know how they are truly supposed to sound as would be the case for anyone who was at those recording sessions. For example if I say the Triplanar arm reproduces bass better than any other tone arm I've heard its because I was there and have the master tapes; other arms simply don't seem to get the bass right. So my suggestion to you is simple- get some good quality recording gear and make your own recordings so you can make accurate statements about things rather than speculation posed as fact. |
Here’s a great vinyl, containing some sustained, 16Hz, pedal notes. They also did a great job of capturing the hall acoustics. It worked nicely, in concert with a Spectrum Analyzer, for testing my woofer cabinets. Much more enjoyable, than Pink Noise. https://www.discogs.com/Virgil-Fox-The-Fox-Touch-Volume-One/release/2356270 |
Dear @pwhinson : """
point of 28hz. BUT of course there's just very little music down there....""" there are a lot of recordings with usable music information below 20hz and in both formats: LP and CD's. Some like these ( exist hundred of recordings, this is a enunciative list/examples. ): almost all Telarc recordings that not only goes below 20hz but as low as 6hz-8hz like in the 1812 overture, many Reference Recordings as Dafos and Berlioz Fantastique, obviously organ scores by Bach and other composers, Sheffiel Labs in its Firebird recording and in other recordings by them, M&K D2D has some recordings too, many rock music recordings, two notables here are The Wall, Dark Side of the Moon, last live Hotel California recording, hundred of Original Soundtrack Motion Picture in CD and some in LP too like: Glory, 300, Gladiator, Vangelis 1842, Blade Runner ( first picture ), the old " The Mission, et, etc. All those comes with information below 20hz and only if we own true subs that performs at least at 14hz-16hz can we " discover " the beauty of those recordings. A true subs is not the one that goes to 20hz but the one that gows way down below 20hz with low THD. To achive that subs needs at least 12" to move the air need to and very good design. Ideally subs need to have at least woofers from 14" and up. For a 10" woofer ( as the four subs array posted here. ) is almost imposible to handled frequencies below 20hz at over 100dbs ( SPL. ) and with low THD kind of distortion. Btw, one of the ribbon speakers I was refering in my other post to you was the Apogee that I live with for a couple of months at my place ( several years ago, when Apogee was the " week new speaker " name. ) with the Scintilla's powered by my Classé DR3-VDH that was one of the few amplifiers to handled the speaker so low impedance of 1 ohms or the like. Well I listen too several times through the audio distributor its top of the line that was a full range one with hybrid design due that came with a integrated subwoofer and I can tell you that contrary of what the Magnepan designer thinks performed excellent but I did not have the kind of money for buy it. I'm not talking of the Diva that was a great performer too but about The Grand, here you can read that exist only fortunated 25 owners all over the world: http://www.reality-audio.com/the_grand.html So don't be afraid to make the same and enjoy your system better than ever before or after ! ! ! ! Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
Dear @clio09 : Here a definition of the word artifact: """ ar·ti·fact/ˈärdəfakt/noun
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@clio09- That’s why I mentioned, "semantics". I’m envious of your location. Currently; I’m stuck in a culturally-challenged hick-town, after living the major portion of my life, between Cleveland and Orlando. No dearth in either local(unlike here), regardless of music genre desired. Happy Listening! |
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I am out listening to live music once or twice a week. Living in the SF Bay Area there are no shortage of events, from local spots to well known venues. I've also been fortunate to record or obtain recordings of many of the events I attend. I believe in many of the attributes used in the definition of "tight bass" that have been posted. It's the term itself I don't agree with. That was the reason I asked and why I felt Ralph's response was notable. |
Dear @rodman99999 : As @bdp24 you explained very well in what you posted before. That " artifact " certainly means nothing about what clio ask before. Noble 100 posted something very good as an audiophile, something like: " when you hear it you will know. " For that " will know " we must to have a near field position live music experiences in different venues ( several of those experiences. ) and with different kind of MUSIC. Obviously that clio has not those experiences because if he has it then why to ask for or maybe he only want to confirm what he knew. ! ? ! ? but if he knew then what about that " artifact ". Certainly: artifact is not the answer for me but for he is the rigth one, good even that maybe he had not those experiences. Who knows? Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
Dear @pwhinson : You have great passive speakers but even those could be improved making changes/up-grading in the bass range. I would like to know which is the frequency range ( wide. ) handled by that quasi-ribbon bass " module ". The specs says that from 25hz but does not mention a crossover frequency range and was not mentioned too if that 25hz is its +,- 3db point because if not then those 20.7 in reality perhaps goes not more than true flat 30hz. Even that are quasi-ribbon design and normally low distortion levels exist true distortion levels in the kind of IMD developed by the bass driver that affects all the other non-true bass frequencies handled by that driver and this IMD generated could goes lower. I know that the Magnepan designer does not like hybrids designs but other ribbons designs came with integrated subs and works really great. From my point of view the noble 100 solutions are only an opinion and for me not the best option. You said that maybe there is no much information below 25hz and I can tell you that even below 20 hz exist recorded information that's really valuable if youy room/system can shows it. The Swarms solution goes down to 20hz only: 18hz in ported/vented fashion or 22hz in sealed fashion. Is it a complete solution?, not for me: it's a quasi-solution. The 20.7 crossover frequency is a must to have before you take any solution about . Subs are not only to have evenly low bass room/system response and goes deeper in the bass range but perhaps more important that those is to take that IMD distortion levels at minimum and with this your overall quality performance levels will go higher and you will enjoy those 20.7 better than ever before. Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
@rodman99999 When I first built my woofer system, it was designed(1980-81) to mate well with my Acoustat Model IIIs. It’s worked seamlessly, with everything(mostly planar) I’ve owned, since(various active crossovers, amps and one driver change, but same transmission line cabinets). My distributed array woofers are used with Acoustat Model IIs with the Acoustat direct drive amps and a Beveridge RM-3 active crossover. I feel it is very well integrated and also works well with other speakers (Quad ESL and Spendor 1/2e). I don't think Duke LeJeune gets the credit he deserves for following this path and his DBA design certainly inspired what I am doing today. Of the response to my question that I have seen so far, I thinks Ralph's is notable for his reference of tight base as an artifact of sound reproduction. |
Dear @noble100 : As the other gentleman I already posted you are loosing the main focus of bass management and you are doing because as lewinsky you are deffending some one that does not needs no one deffended him because no one is attacking him. Please read my last two posts. I only disclose facts, attacking no one in any case he is " attacking " him self for what he posted. Last but not least: he has not first hand experiences with the subs overall subject in his own room/system. In the other side I know very well whom is atmasphere and maybe better than you. Period. R. |
Dear @lewinskih01 : but how can a universal amplifier design handled woofers ( passive speakers. ) in better way that the dedicated amplifier on a self powered subs that was designed in specific to fulfill the woofer needs? makes you sense too? I'm sorry but now your last posts to me make no sense at all. Please don't lost or move from the subs focus/specific subject. Forgeret about atmasphere but not because you want to " deffend " it ( that tehre is no reason to do it because you have to deffend him for nothing because no one is against him. ) lost the main subjects in this thread. R. |
Dear @lewinskih01 : Good that make sense to you but I think that you are losting a main critical premise/parameter/characteristic on the subs overall subject, been 2 or 4, and is that separated subs ( 2-4 . ) is the way Harman speaks and I additional posted that a main target integrating ( at least. ) two subs is to put at minimum the IMD levels in the main speakers and both targets, the Harman and mine, can’t be accomplished in the way your " common sense " says to you. Got it the huge differences? 2 or four subs permits to place it in the ideal position for the room/system and the same time that the IMD in the main speakers goes way lower than ever. You can't or maybe is almost imposible try to find out/playing with several positions of two subs along the main speakers woofers . Normally the main speakers mid/high frequency range we already has/set up in the rigth main speakers position and we can't make many position changes to see if the bass improves and with out lowering the main speakers IMD ! ! In the other side and again makes no sense to me follow talking of more than one seat position to listen a stereo room/system because exist only one seat position that is " rigth/correct " to listen spot-on the mid and high frequency ranges. Who cares other than one seat position to listen it if really does not exist. Makes sense to you? or is that you only listen to the bass range? ! ? ! ? ! ! My post is not against atmasphere and again I’m only disclosing facts that he showed don’t understand very well yet. I’m sure that when he already have his two subs his way of think could be a little different or maybe not ? !. Regards and enjoy the MUSIC NOT DISTORTIONS, R. |
pwhinson: " I have to admit that with my Magnepan 20.7's I have toyed with the idea of adding a subwoofer but in the case of the 20.7's in my room they measure flat down to about 28hz and only then start to roll off. So I would not want to crossover the signal "from" the maggies to a sub, rather I would want to blend a sub in beginning at around that point of 28hz. BUT of course there's just very little music down there I don't believe however." Hello pwhinson, I've only listened to the Magnepan 20.7s once (driven by either Boulder or Bryston amps at Audio Connections near Chicago) but still know I'd definitely already own a pair if I was only richer. I remember the sound as the usual great Magnepan midrange, treble and imaging of their top model combined with a much deeper bass response than I was expecting. It was not only well extended deep bass but incredibly high quality bass that was just as fast,smooth and highly articulate as the midrange and treble response, resulting in a seamless quality to the sound from top to bottom that was very impressive. You're correct that there's not a lot of musical content requiring reproduction of frequencies much below the 20.7's bottom limit of 25-28 Hz. I'd only suggest adding subs to your system if any of the following is important to you: 1. A system that's completely capable of reproducing all humanly audible frequencies from 20 to 20,000 Hz. While it's true that there are few recordings with deep bass down to 20 Hz, and if it exists it's probably summed L/R ch mono bass, there are some that do contain bass this deep (but not none on vinyl) and you'll only know it's there if your system is capable of reproducing it. There's also the possibility that new physical or downloaded music formats are introduced that allow for full range (20-20K Hz) recording and playback. I have no advanced knowledge of any new formats but even some existing formats (like cds, blurays and hi-res digital files) are currently capable of full audible range recording and playback. It may also be useful to consider the types of music you listen to. I believe only pipe organs, classical, some rock/jazz and electronica contain notes this deep. 2. A system that is currently used for both music and home theater or you're considering using it for ht use in the near future. There's an abundance of sound effects and even some music that has very deep bass content on ht content like regular and 4K bluray discs as well as many premium channels on subscription HDTV services. If either of the above is important to you, I believe adding subwoofers to your system would be beneficial. I think you have 2 options if you're interested in extending and improving the already very good bass performance of your 20.7s. One option is to add 2 good powered subs of your choice and experiment with their positions in your room as well as the volume, crossover frequency and phase control settings on the subs until the bass sounds best to you (smoothest, most natural and most seamless integration with the 20.7s). I suggest you use 2 subs, rather than a single sub, because 2 will provide faster and more agile bass that more closely resembles the bass supplied by your 20.7s as well as better smoothing and adding impact to the overall bass response in your room. I would also advise you to calibrate the best bass response for music because, in my experience, this will also work well for ht use, too. Of course, the brand and model of the subs is your choice but I'll recommend a few that I think might work well in your system and room: JL Audio F110- 10" long-throw aluminum driver, 1,200 w amp in a sealed enclosure, 13.5"W x 14.24"H x 16.51"D and 52.7 lbs., about $1,500 ea. REL T9i- 10" long-throw aluminum driver, 300 w amp in a sealed enclosure, 13"W x 15.2"H x 16"D and 41.3 lbs., about $1,300 ea. SVS SB1000- 12" fiber composite driver, 300 w amp in a sealed enclosure, 13"W x 13.5"H x 14"D and 27 lbs., about $500 ea. I'm fairly certain the addition of 2 subs, properly positioned and configured, would prove to be a good improvement to your system's overall bass response for both music or ht. The major downside to this approach is that it would only extend your deep bass response to about 24-25 Hz. You would clearly perceive a smoothing to the bass and additional bass impact but, unfortunately, no deeper bass extension. However, I'm certain that another option, a 4-sub distributed bass array (dba) system, would prove to be the greatest improvement to your system's overall bass response and, in my opinion, the best solution I'm currently aware of for supplementing and extending the bass response and integrating seamlessly with any pair of speakers, but especially with 'fast' and detailed speakers such as planar-dynamic and electrostatic panels. I'm certain this system would work very well for your system because I've been using a dba system with my fast Magnepan 2.7QR speakers for about 4 years now. I realize the 20.7s are far superior fast speakers than my older models, but the forces behind dba systems' excellent bass performance and integration work equally well with virtually any pair of main speakers. This system has worked so well for my system that I started a thread about it a few years ago, here's the link if you'd like to know more details: https://forum.audiogon.com/discussions/anybody-else-using-a-distributed-array-sub-system Also, here's a link to an Absolute Sound review of the Audio Kinesis Swarm dba system, which is almost identical ( the Swarm subs are just a bit wider and shorter) to the AK Debra dba system that I own: http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/ There are 2 options if you're interested in setting up a dba in your system: Complete AK Swarm or Debra complete dba system- these include four 4 ohm subs with removable port plugs for either sealed or ported operation, each sub has a 10"aluminum long-throw driver, 14.5"W x 23.75"H x 10.375"D and 43 lbs., and a Dayton Audio SA1000 1K watt class AB mono sub amp that powers all 4 subs, about $2500 for the complete system. Custom dba systems- these would involve buying 4 powered subs of your choice and positioning them asymmetrically within the room for optimum performance. This is the most flexible method of creating a dba system since you can choose the quality of the subs used for bass extension and maximum spls. Either AK dba complete dba system will provide flat frequency response from 20-100 Hz with a maximum output of 113 db at 20 Hz. The bass extension and frequency response performance levels of a custom dba system will vary depending on the exact subs selected. The excellent bass integration quality with your 20.7s, however, will not vary depending on the exact subs selected and will remain constant. Which means a very good dba system could be created for as little as $2,000 if 4 SVS SB1000 subs were used but an 'ultimate' dba system could be very expensive if very hi-end subs are used. Considering this, either AK dba may be the best bargain given their high level of performance in bass extension, accuracy and maximum spl level. Sorry I wrote you a book but I wanted to give you as much info as I could. Tim |
rauliruegas, I don’t understand why you’ve been going after atmasphere/Ralph, either. Yes, his primary business is designing and selling high quality tube gear but it’s a mistake to assume his audio knowledge and experience is limited because of this. I’ve been reading his posts for years and it’s obvious he has an abundance of knowledge on a wide range of audio subjects that I’m sometimes surprised by. For example, he knows Duke Lejeune, owner of Audio Kinesis that sells the Swarm and Debra 4-sub distributed bass array systems, and is well versed on the subject of attaining good bass response in rooms smaller than recital halls. He’s been setting up very good sounding systems in small audio show rooms for years, often utilizing subs and dbas to get the bass sounding right in these rooms which is almost always very difficult to do. His personal system speakers are capable of very good deep bass output down to 20 Hz but he’s still adding a couple of custom subs because he already knows through experience that this is the best method to further smooth and improve bass response in his entire room. I’ve explained the above because it appears from a few of your posts that you’re unaware of Ralph’s breadth of knowledge and experience and the value many Audiogon members, including myself, place upon the information, opinions and advice he shares on a consistent basis. Thanks, Tim |
@rauliruegas You are really mad at Ralph. Oh well... FWIW: and he still posting that he needs only two subs because his speakers goes down 20hz ( solid hz. ): so what?, that confirms that he did not understand yet the overall subject in this thread and in the reality of any room/system I believe he's talking about the same approach Earl Geddes, Hartman, etc do: 4 sources playing subwoofer frequencies to flatten response across multiple seating positions. In his case, per his comments, his mains go down to 20Hz so they are playing in the subwoofer region as well. He will add two subs in parallel to the mains so he will end up with 4 sources playing subwoofer range. That's all. Common sense to me (coupled with some theory/knowledge). |
I have to admit that with my Magnepan 20.7's I have toyed with the idea of adding a subwoofer but in the case of the 20.7's in my room they measure flat down to about 28hz and only then start to roll off. So I would not want to crossover the signal "from" the maggies to a sub, rather I would want to blend a sub in beginning at around that point of 28hz. BUT of course there's just very little music down there I don't believe however. |
What bdp24 said, +1. Get around a rhythm section(within 25 feet), that’s played together for any length of time and you’ll understand, "tight Bass". For(most) anyone that’s been around the real thing, for any length of time, it’s mandatory in the listening room. Far as semantics: "tight" generally refers to how cohesive a group sounds. When applied to a system (in my personal thesaurus, anyway), how well the lowest notes are detailed and how easy it is to follow each rhythm section player’s individual lines(given a well mixed/mastered recording, everything in phase and balanced). Then too, there’s the recording venue’s ambiance info, much of which is carried in the lower registers. ie: Dead Can Dance(Spirit Dance/Yulunga, especially) can place one in the Quivvy Church’s auditorium/studio, with the right setup. When I first built my woofer system, it was designed(1980-81) to mate well with my Acoustat Model IIIs. It’s worked seamlessly, with everything(mostly planar) I’ve owned, since(various active crossovers, amps and one driver change, but same transmission line cabinets). |
Dear @bdp24 : You are rigth, live event experiences is a must to have and understand the home system bass management. We need ( as you already have. ) first hand experiences trhough live event experiences seated at nearfield positions ( in different venues. ) to try to approach that live bass experienced. We always will be not even near the live experiences but at the end the end our target must be to " approach " it. Maybe the bassm management range in home systems is the most complicated target to achieve in the best way we can. Always will be trade-offs where we have to choose in between. R. |
Dear @lewinskih01 : Only common sense. As I posted to you a few months ago that " seller "/atmasphere ( other time I will explain about that word " seller " because it’s no matters in this thread. ) said that his syatem goes down to 20hz no subs needs at all ( in that dicussion what we was discussing was that any passive speakers needs the integration of two self powered subs. ). His answer ( what he posted in that thread. ) only showed his ignorance of the whole subwoofer/bass management because even his field coil speakers and his system will be improved through the addition of two self powered subs not 4. Suddenly in this thread he gaves opinions as if he really been a true expert on the whole subject when even today he has no first hand expeiences in his room/system with subs, go figure. From where he already knows for sure what is posting. I’m not attacking him but only disclosing those facts. That he be a tube electronics manufacturer does not means knows everything about everything in audio because at least in the subs/bass management whole subject it’s ignorant as you, me and any one else are ignorants on several subjects/topics in audio. Look, I took around 1/one full year to integrate my subs in my room/system. A full year with " thousands " of tests till the subs were very good integrated to. More than 16 years ago I was thinking exactly as atmasphere that because my ADS L2030 speakers goes down to 18hz I just do not need subs in my system. I was totally wrong and was till I try and learned about subs that I added to my room/system and igf you look to my subwoofer thread that I posted in the analog forum its date is 2005, this is almost 14 years ago. The first discovery for me was not if my system bass was now " rigth " but the paramount differences ( for the better ) that makes that I put at minimum the IMD of my ADS L2030 and till today I still think is the main improvement followed by all what we subs owners already experienced with. No one can try to shows him self as a knowledge man just reading with out first hand experiences in his room/system. Btw, for me makes no sense to have 3 or 5 bass evenly in any room/system because for the mid and high frequency range exist only one " rigth " seat position no matters what. What we have to take care in deep is that at our room/listening seat position the bass, mid and high frequency ranges stays spot-on and that’s it. Two subs are enough to acomplish that. Harman tell us in precise and scientific way: 4 are the ideal but two are enough. Ideal for more seat positions but 90%/95% of the quality performance levels we can accomplish with two subs, yes it will takes a little more time to do it but we can do it. No, not one full year as I took where the main reason wa that I was totally ignorant on the whole bass regards and I did it alone with no advisors or the like and really was a huge learning lessons because I learned several other audio subjects other that the bass management. I know that you already has very good knowledge levels with the subs but for new comers about this link could help: https://www.audioholics.com/home-theater-connection/crawling-for-bass-subwoofer-placement Regards and enjoy the MUSIC NOT DISTORTIONS, R. and he still posting that he needs only two subs because his speakers goes down 20hz ( solid hz. ): so what?, that confirms that he did not understand yet the overall subject in this thread and in the reality of any room/system. |
@clio09, I think of bass reproduction in terms of leanness vs. plumpness. I’ve worked some with upright bass players, so have heard them up close in all kinds of acoustic environments. I have also heard them from the audience side, both unmic’ed and mic’ed. The fault I hear in it’s reproduction is that of making it sound too "round", not as "stringy" and "sinewy" as it sounds live. In person, an acoustic bass sounds like it is part of the string family in an orchestra, not that different from a cello, just playing lower notes. As for electric bass, I use the sound heard by the playing of bassists in my own situations (Fender of course---Precision, Jazz, and Telecaster basses, but also Gibson, Guild, Danelectro/Silvertone, Hofner, and even the awful Rickenbacker ;-) as a reference, but also that of Joey Spampinato (NRBQ)---whom I have heard up close in a small club (The Roxy in L.A.), and John Entwistle (The Who), playing his original Precision at The Carousel Ballroom in San Francisco. Spampinato has the ability to make his Silvertone sound like an upright, coolest thing I’ve ever heard! Entwistle had the most massive bass sound I’ve ever heard (awesome!), with lots of staccato attack, but it was still not "fat". He was a GREAT bassist! I sure would have liked to see and hear James Jamerson live. Brian Ding of Rythmik and Danny Richie of GR Research speak of a woofers ability to stop quickly when the signal ends as a major requirement for good bass reproduction; the lack of "overhang". There is also "overshoot"---the woofer traveling just a little past where it "should", smearing the bass in terms of it’s transient/temporal characteristic That’s as good an explanation as I’ve heard. But all the above is about the reproduction of the bass as an instrument. In regard to over all bass balance in home hi-fi systems, rarely do I hear reproduced music with the bass weight and heft I hear at live music performances. Live music is much more "physical" than is reproduced, that physicality mostly low frequency in nature. A large part of that has to do with SPL, but also the size of the rooms music is performed in. Large venues support longer wavelengths (lower frequencies) than do smaller ones, and sound very different from our listening rooms. The final frontier in music reproduction! |
Can someone define for me what "tight" bass is.An artifact of sound reproduction. It does not seem to occur in real life. Punch but no detail, in a nutshell. To address Raul's attacks against me: I don't sell speakers of any sort. I recently moved, and now have a standing wave in my new listening room. I've seen how effective the Swarm addresses this so I know they will work in my situation. I only need two, as my speakers go down to 20Hz no worries. |
clio09, I can only tell you what my definition of 'tight' bass is, which I realize may be a term that has different subjective meanings to others. A bit difficult to describe but easy to identify when you hear it. Tight bass to me means accurate, solid and natural bass. The leading edges, the pitch and tone, the duration of the sound, the volume, the impact and the decay of the bass all are perceived as accurate and natural. There's also no sense of exaggeration, attenuation, blurring or something added to or missing from the bass. In other words, the sound of bass instruments sound right and tight, just as they sound when played well and heard live in person. I've also personally noticed that, if the musicians get too drunk, then you often don't get that proper degree of funk. Tim |
steakster I moved my Talon Roc out to sell and have more room. But it turns out I have plenty of room. Soon as I can find the time its going back in. Mine's powered so I will be able to set it to do very little but add a little at the extreme low end. If it even will do that. Was never able to get it to go as low as my bass array does already, but then with one you are forced to locate it for least bad overall. So we will see. |
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