Do you think you need a subwoofer?
Raul: "According to scientific studies four subs are optimal in a home audio system." As a user of the 4 sub approach for the past year, I can attest to the validity of these scientific studies. I've found the 4 sub approach has been an excellent solution for bass performance in my 23' x 16' living room. My system is used about equally for 2-ch music and 5.1 surround HT. I use an Audio Kinesis Debra distributed bass array system that consists of 4 non-amplified subs (each sub is ported, has a 10" driver, weighs 67 lbs. and measures 23.75″ x 14.5″ x 10.375″) and a 950 watt class A/B amp with variable crossover and phase controls. Total price for the system is $2,990 and there is a choice of woods. I was originally considering getting 2 high quality powered subs like JL, REL or Vandersteen but discovered the Debra 4 sub system while reading about the scientific studies that Raul references above. These were studies by Acoustical Engineers Dr. Geddes and Dr. O'Toole that were concerned with bass wave propagation in residential and commercial spaces. Here's a summary of their key conclusions: Sound waves behave differently in typical rooms below and above about 200 hz. Low frequency sound waves are so long ( a 20hz sound wave is 56.5 ft. long) that they'll bounce off room boundaries until they run out of energy. These initial and subsequent long bass waves eventually overlap and meet which creates standing waves at various points in a room. These standing waves result in bass peaks (perceived bass overemphasis) bass dips (perceived bass under-emphasis) and even bass cancellations (no perceived bass) at various points in a room. They were able to mathematically predict and plot precisely where standing waves, and their corresponding peaks, nulls and cancellations, would exist in a room based on the location and number of bass sources (subs), bass frequency, room dimensions and boundary materials, They found a relationship between the number of bass sources(subs) in a given room and the resulting number of standing waves in the room; Basically, the more subs in a given room the fewer bass standing waves are created and the better the bass. They note that there is, of course, a practical limit to the number of subs users will deem acceptable. As a result and perhaps the most crucial conclusion they reached concerning the use of subs for residential and commercial spaces, was that the use of 4 subs in a given space resulted in the elimination of the vast majority of bass standing waves in that space. Each additional sub beyond 4 only resulted in marginal improvements. The DEBRA and SWARM distributed bass array systems are both based on the Geddes and O'Toole studies and conclusions and they both, unsurprisingly, utilize 4 subs. I honestly believe it would be almost impossible to overstate how well the DEBRA system has improved the bass performance in my room for both music and HT. I use Magnepans for my L/C/R channels and, as many of you know, they have been notoriously difficult to integrate with subs. The bass is solid and tuneful for music and powerful, impactful and even startling on HT. With so many people using bass traps, microphones, room analysis and correction software, equalizers and digital signal processing to improve low bass performance in their rooms, I find it ironic and a touch humorous that the best solution available thus far is adding more subs. I don't want to leave the wrong impression, I am not wealthy and $2,990 for a sub system is expensive to me, too. I rationalized the cost as being less than the cost of 2 high quality powered subs and that it's likely the last bass system I'll need to buy. The progressive and precise setup procedure is fairly elaborate and took me most of an afternoon to complete. The subs are wired in parallel and it's recommended that 1 sub have its phase inverted. Thanks, Tim |
For anyone seriously considering deploying a distributed bass array system in their system and room, I believe the thought of where to locate 4 subs is a common concern. It was definitely a concern of mine until I went through the rather extensive setup procedure that determines the ideal spot for each sub. I'll describe my experience so that readers can better understand the process and how these concerns were remedied in my installation: My living room serves as the home for my combination music listening and 5.1 HT system. It is 23 ft long and 16ft wide. My 65" hdtv is wall mounted roughly in the center of the front 16 ft wall. There is a Magnepan 2.7qr panel (each 6 ft tall and 2 ft wide) on each side of the tv that are both about 4 ft out from the front 16 ft wall and 1 ft in from each 23 ft side wall. There is a Magnepan CC3 center ch speaker centered above the tv that is wall mounted. All components reside on or in a 5 ft wide by 1.5 ft tall audio cabinet located below the tv and against the 16 ft front wall. The primary listening seat is centered on the rear 16 ft wall with a 7 ft sofa along the right 23 ft wall and 2 chairs along the opposite 23 ft wall. There was not a lot of open space in this room when I began the setup procedure. The setup procedure is: Sub#1 is hooked up and placed on its back (driver facing the ceiling) at the normal listening position. Music is played that has good and repetitive bass. Walk around the edges of the room and determine exactly where the bass sounds best to you. Attach the 3 spiked footers to Sub#1 and position it upright facing the nearest wall to the spot you determined the bass sounded best. Sub#2 is hooked up and placed on its back at the primary listening position. With sub 1 & 2 playing, continue walking around the edges of your room and determine again where the bass sounds best to you. Attach the 3 spiked footers to Sub#2 and position it upright facing the nearest wall to the spot you determined the bass sounded best. Repeat this procedure for sub 3 & 4. Small positioning adjustments may need to be made for each sub due to avoiding furniture and the WAF. Once completed, final sub hook up is done in parallel: Attach a single wire from the amp's speaker A's pos. output terminal and to Sub#1's pos. input terminal. Attach a single wire from the amp's speaker A's neg. output terminal and to Sub#2's neg. input terminal. Attach a single wire from Sub#1's neg. input terminal to Sub#2's pos. input terminal. Attach Sub 3 & 4 using this parallel method on the amp's speaker B's output terminals. I ordered single, high quality and low gauge speaker wire along with the sub system for a very reasonable price. Once the ideal locations for the subs was determined, I drilled holes in my room's floor to the crawl space below, and was able to hide the connecting wires. The final positioning turned out not to be an issue, with the best sounding positions actually being discreet and unobtrusive. The 2 front subs are each located directly behind my main panel speakers and are not even visible from my primary listening position. The 2 rear subs are each located along each 23 ft side wall about a foot in from the rear wall. The left wall sub is concealed from view by a leather recliner and the right wall sub is concealed behind a large end table. My primary listening seat is between these 2 rear subs. I should mention I've never had my system/room analyzed using a mike and software. From my purely subjective perspective, however, I'm confident the results would be good since I spent hours on the setup and critical listening from all six listening positions in my room. I would suggest this type of sub system as a viable alternative for anyone considering investing in one or more quality subs. The system is rated clean at 113 decibels at 20 hz. I've often heard and felt it go this deep. It feels and sounds clean and right but I can't verify the frequency, decibels or lack of distortion. Sorry this turned out so long and windy, Tim |
lewm: " Tim, Was this last post intended to make the rest of us feel good about the prospects of installing and positioning four subs in a listening room? If so, it didn't work." Hi lewm, Yes,I was trying to mitigate the angst many likely experience at the thought of positioning 4 subs in their listening rooms. My post was meant to convey that I was concerned about this, too, but that it was easier to incorporate 4 subs into my room than I initially thought. In your case, unfortunately, you're not buying what I'm selling. I understand this solution may not work for everyone. My only motivation for posting at all was to share what I know is a very effective method of attaining excellent bass response in any room that works well for both high quality 2-ch music and HT. It is the only method I'm aware of that has this capability along with eliminating the vast majority of bass standing waves in any room which results in consistently accurate and tuneful bass throughout the entire room no matter where you are standing or sitting. " I would hate to have to watch out for tripping over subwoofers whilst walking around the room to change records, or when we are entertaining guests at parties. I'll talk to Duke." I think you would be well served by talking to Duke LeJeune at AudioKinesis. In your case, I would suspect that you'd likely find the subs would sound best in the following positions: The front 2 subs along the front wall behind, and discreetly hidden by, your large Sound Labs. One each of the back 2 subs opposite each other at some points along your side walls. This is only an educated guess and, of course, only you could determine if these positions would work for you. I actually think the Debra or Swarm 4 sub system, with 4 dispersed 10" woofers, could be an ideal match for integrating well with high quality, fast electrostatic panels like sound Labs. My only concern would be the possibility of the 2 side wall subs transmitting vibrations to your turntables along your rear wall. I have no dog in this fight, but I really believe you would be pleasantly surprised how well a distributed bass array system could work in your room. Please discuss with Duke. Thanks, Tim |
Raul, I think I'm getting the gist (main idea) of what you are saying but please correct me if I seem not to understand. You are making the effort to communicate in writing in English as a 2nd language which I understand must be difficult. The least I can do is make the effort and take the time to understand your meaning as best as I can. I do not want you to stop posting, since practice is likely only going to improve your English written skills. Thank you, Tim . |
Hi Raul, I'm glad that you're very pleased with your system's performance after you added the electrical line regulators. I'm not exactly sure what regulators these are but I'm very interested in them since reading about your great results. After re-reading your posts, I found that we agree on several opinions: 1. The importance of a low noise floor not only in presenting music recordings accurately, with more easily heard details and enjoyably but also because it enables the affects of small changes ('tweaks' such as power regulators, turntable tone arm/cartridge/VTL setting changes, power cord/speaker cable/interconnect cable changes, etc.) to be more clearly heard due to this increased accuracy, neutrality and audible details. You achieved accuracy, neutrality and a low noise floor via component selection and your regulators. I achieved this mainly through a change from a class A/B amp to a pair of class D mono-blocks (Aragon 4004 to D-Sonic M3-600-M). I believe my mono-blocks have built in regulators that conditions the electricity prior to introduction into the amp's input stage. We use slightly different methods of regulating the home electricity going into our systems for the same purpose of eliminating artifacts and lowering the noise floor. 2. The importance of good bass response in not only extending the frequency response lower for a more realistic experience but also because of the affect that good bass response has on improving a system's mid-range/treble performance and resultant improvement in a system's ability to create a more solid and stable sound stage illusion. You have achieved good low bass in your system by fine tuning the positioning of your 2 Velodyne subs over a period of years and I achieved it through the use of the 4 sub Audio Kinesis distributed bass array system following their progressive setup procedure. The important thing is that, through slightly different means, we've both achieved good bass response in our rooms. The less important question of which method performs best, will have to remain an open question I think we both agree that the most important thing is that we're both happy with our systems and enjoying our music. Thanks, Tim |
I thought readers of this thread might want to read a professional review of the 4 sub distributed bass array system I discussed previously: http://www.theabsolutesound.com/articles/audiokinesis-swarm-subwoofer-system/ This is actually about Duke Lejeune’s Swarm system but it’s virtually identical to James Romeyn’s Debra system that I own; exact same 4 ohm subs with 10" drivers, 1,000 watt class A/B ampifier along with the exact same setup procedure and wiring method. Again, a reasonably priced system that delivers excellent bass in any room for both music and ht without the need for any room treatments and without any room analysis/room correction software or equipment. Yes, you do need to accommodate 4 (1 sq. ft. footprint and 2 ft. tall) subs in your room but it delivers the best bass response I’ve yet experienced in my room. I just want to let everyone know how well these systems work. Thanks, Tim |
Hi Raul, You asked: " I was trying to find out information of what typical level of THD has a bass/subwoofers configuration as the one you have but it does not exist something about. I think that that information does not exist for a specific room/system. I checked the James Romeyn Debra, Audio Kinesis Swarm along with google searches sites and I think you're correct, there is no info regarding THD on distributed bass array systems. I did find an interview with Duke Lejeune, in the Stereo Times http://www.stereotimes.com/comm081710.shtml He mentions that when he started designing speakers his goal was low distortion and accuracy. But, when he was finally close to meeting these goals, the speakers did not sound good at all. He was talking about his full range speakers but this may apply to his Swarm system as well. I think you may be more concerned with THD than I am because I honestly have never perceived any negative qualities that I'd attribute to distortion on music or HT. |
enginedr1960, Congratulations, I'm glad the distributed bass array system works as well in your room as it does in mine. I'm not really surprised since this method has been proven to work in numerous rooms no matter the size or shape. But, if you don't mind, could you give us a few details such as: Are the 2 additional subs you added the same brand and model as your original 2 subs? Are your subs self amplified or passive (driven by separate amp(s))? What method did you use to locate the subs in your room? Where did you windup locating the 4 subs in your room? Do you use your system for 2-ch music, HT or both? I think I've stated my system is used for both 2 ch music and HT and, just as you stated, "the whole system just sounds right" for both. I still find I'm amazed how well the distributed bass array system works and with absolutely no room treatments, microphones, software programs or equalizers required. I know the distributed bass array system is scientifically based and has been empirically verified by numerous independent acoustic engineers and users but I'm still amazed how well it works. Taut, powerful and textured bass that integrates seamlessly and just sounds life-like and right. Thanks, Tim |
lewn, As you are well aware, the Sound Lab 845Pxs are excellent speakers that are capable of going fairly deep (26 hz). However, I believe a distributive bass arrray (DBA) would be a very good solution in your system for several reasons: 1. The bass produced by a DBA, using 4 10" driver subs, will be seamlessly integrated into the sound coming from your sound Labs; capable of being as quick and detailed as the Sound Labs or deeper and more powerful depending on the source content. 2. Using a DBA will relieve your OTL amps and the Sound Labs from reproducing the more demanding lowest frequencies., the supplied separate class A/B amp would be powering the bass (if you go with the Audio Kinesis Swarm or Debra DBA) or the internal class D amps on the mini-subs would be powering the bass (if you go with the Rel q201e subs that enginedr1960 uses). You could then turn down the bass level to taste on the Sound Labs. I think the result would be even better performance from the Sound Labs (especially in increased dynamics) since your OTL amp would mainly be powering the mid-range and treble with bass level powering reduced by the amount you determine sounds best. 3. Using a DBA as described above will significantly reduce the amount of crossover circuitry in your system's signal path. There would only be crossover circuitry in the bass level that is built into both the Audio Kinesis separate amp or each individual powered sub. You would customize the bass to your preference by a combination of reducing the bass output level on your Sound Labs and adjusting the crossover frequency and volume setting on the Audio Kinesis DBA separate amp or each individual powered mini sub. A bit cumbersome but it would provide great flexibility in dialing in the bass to your exact preferences. 4 Room aesthetics would be minimally affected. I replied to you in an earlier post about this. Basically, I described how my 2 front subs are hidden behind my 2ft wide panel speakers and the other 2 (each along a side wall near a back wall) are partially hidden by a leather chair and an oversized end table. My room is 23ft x 16ft with an 8ft ceiling and I barely notice them. I think your room may be even larger. Your panels are also even wider at 3ft so, as long as you determined through the setup process the subs sound best at those positions, they would be completely hidden from view. That just leaves the rear 2 subs that need to be creatively hidden. Just my thoughts but I really believe a DBA would be a great sonic match with your Sound Labs. Tim |
enginedr1960, If someone is not buying a complete DBA (distributed bass array) such as the Audio Kinesis Debra or Swarm systems, I think the Rel q201e mini subs might be the ideal sub to use in a custom 4 sub DBA as you assembled. These subs are similar to the Debra and Swarm subs; compact and they utilize 10" drivers. Great choice. I just have a few suggestions for you and your custom DBA: 1. The DSPeaker Antimode 2.0 and Mini DSP 2 x 4 may have been good tools when utilizing 2 subs but I really don’t believe they’re necessary in a 4 sub DBA. You may want to use the Antimode to verify after the first 2 subs are positioned optimally by ear but I doubt any signal processing will offer any sonic improvements. I don’t think the 2 x 4 will be needed either. I’m certain there is no need for microphones, analyzing or correcting software, equalizers or room treatments when the proper progressive setup procedure is followed. 2. The proper progressive setup procedure is the following: Sub#1 is hooked up and placed on its back (driver facing the ceiling) at the normal listening position. Music is played that has good and repetitive bass. Walk around the edges of the room and determine exactly where the bass sounds best to you. Attach the 3 spiked footers to Sub#1 and position it upright facing the nearest wall to the spot you determined the bass sounded best. Sub#2 is hooked up and placed on its back at the primary listening position. With sub 1 & 2 playing, continue walking around the edges of your room and determine again where the bass sounds best to you. Attach the 3 spiked footers to Sub#2 and position it upright facing the nearest wall to the spot you determined the bass sounded best. Repeat this procedure for sub 3 & 4. Small positioning adjustments may need to be made for each sub due to avoiding furniture and the WAF. Once completed, final sub hook up is done in parallel (which you can ignore since you’re using self powered Rel subs): Attach a single wire from the amp’s speaker A’s pos. output terminal and to Sub#1’s pos. input terminal. Attach a single wire from the amp’s speaker A’s neg. output terminal and to Sub#2’s neg. input terminal. Attach a single wire from Sub#1’s neg. input terminal to Sub#2’s pos. input terminal. Attach Sub 3 & 4 using this parallel method on the amp’s speaker B’s output terminals. 3. Your Rel q201e subs are front firing and I assume you have them pointed out into the room. You may want to try the Debra and Swarm method of pointing each driver directly at the wall no more than an inch away from the wall. I’m not sure this will improve your system’s bass performance but thought you should be aware of how it’s done with the Debra and Swarm systems and determine for yourself which positioning sounds best to you.4. As you’re probably already aware, selecting the proper cutoff frequency is very important. My main speakers are Magnepans that only have good and accurate bass response down to just below 40 hz. I run my main spkrs full range and use a 40 hz cutoff frequency For 2 ch music and usually 40-60 hz for HT. My center channel and rear surrounds don’t go much deeper than about 8o hz. so this creates a frequency response hole from 40-60 hz up to about 80 hz bass for HT. When I’ve set the cutoff freq. to 80 hz for HT, however, the bass sounds too boomy to me so I prefer to set it at 40-50 hz and the bass response sounds much better to me even though I know there’s a lack of bass response in the 40/50 to 80 hz range; I find I really don’t miss these frequencies. Your Ohm Walsh 2.2000 monitors go a bit deeper to about 32 hz. so you may need to find the cutoff freq. that sounds best to you. You may also want to try filtering out frequencies below a certain hz(and correspondingly raising the cutoff freq. the subs operate at) to see if your monitors sound even better when their bass duties are reduced. 5. The last suggestion I have (is that applause I hear?) is to sequentially reverse the polarity on 1 of your subs at a time while listening to the same content with good repetitive bass. The idea is that bass response will sound its best with one of the 4 subs running in reverse polarity. The theory is that system bass will sound noticeably better with one specific sub running in reversed polarity. The tricky part is determining which of the 4 subs this is. I cannot verify this improves performance since I was too lazy, and my system bass sounded so good as is, I’ve still not gone through this process. Hope this info and advice helped, Tim |
Hi enginedr1960, I understand the frustrations and compromises involved with the infamous and insideous WAF. I followed the elaborate progressive sub setup procedure rather strictly. I took my time determining exactly where the bass sounded best and clearly noticed the bass sounded the most natural to me located at least a about a foot or more away from room corners; the corner positions definitely reinforced the bass response, causing bass peaks and were sub position sites I knew should be avoided. My goal was to find the precise locations in my room where the bass just sounded natural and right and I avoided all locations where the bass was over or under emphasized. I think this is the reason that none of my 4 subs are located at one of my room's 4 corners. However, I understand your significant other may prefer the subs be tucked way in the corners of your room, the exact locations that are most likely to result in the presence of bass peaks at certain spots in your room where bass response is obviously exaggerated. Just a word of warning, none of the subs should be placed squarely in a corner unless you determine that is where it sounds best, which is unlikely. If you must place a sub near a corner, it's best to position it at least a few inches away from the corner's center along one wall or the other. It seems like you've become too accustomed to using your DSPeak and 2 x 4 to even consider not using them. I still believe there's no need for these tools, or even your Bent Audio volume control, in a properly setup DBA system. However, I may not completely understand why you consider these products so indispensable. Thanks, Tim |
Hi lewm, I already knew the 845s are one of the most efficient Sound Labs ever made (about 89 db). It sounds like your mods made them even more efficient and a good match with your OTL tube amp. I was just listing all the benefits I thought going to a DBA would have in your situation. I now understand you don't really need to decrease the demand on your OTL. You're more interested in a DBA to get a more full-range frequency balance and increase bass definition. I can confirm that a Debra or Swarm DBA will give your system high quality bass that is capable of blending seamlessly with your Sound Labs while it's also able to reproduce deep,powerful and impactful bass when the content calls for it. Just to clarify, Duke sells the Audio Kinesis Swarm and James Romeyn Audio LLC. in Utah sells the Debra system. Here's a link to the Debra system: http://jamesromeyn.com/old-pages/home-audio-gear/dsa-1-0-distributed-subwoofer-array-5-pieces-4k-usd... They're both basically the same 4 sub DBA, with small differences mainly in the subs' construction. James licenses the rights to sell it from his friend Duke. They both come with the same 1,000 watt class A/B sub amp, are both rated accurate down to 20 hertz, about the same system price and share the exact same setup procedure. Either system will deliver excellent bass response that is very evenly dispersed due to the significant reduction in bass standing waves in your room. I didn,t know you bought your Sound Labs from Duke. He'll be able to give you good advice on how well the Swarm would integrate with your 845s. Good idea to give him a call, Tim |
Hi enginedr1960, I agree with you completely, there really are many ways to achieve great sound. I'm very impressed with the home-made distributed bass array system you created with your 4 Rel q201e compact subs and other components. I've been assuming you have no need for your Bent passive Dave Slagle autoformer volume control and Minidsp 2 x 4 simply because I use no such tools in my system and it functions beautifully. I admit my comments were made without a complete understanding of these products and how you utilize them in your system. I took your suggestion and did some research on the Bent passive volume control, the TAP system and the Dave Slagle Singleformer modules. This seems to me to be a seriously high quality product/system and, if this is any indication, you obviously choose your system components carefully. I believe you use this to control the volume and balance of your 2 front Rel subs via an optional remote. I believe you use the Minidsp 2 x 4 units to control your 2 rear subs and perhaps even some room correction.. As you can see from the above, I only have a partial understanding of exactly how you use these products in your custom DBA system. However, I'm sincerely interested in learning more about how you utilize these products in your system. I think sharing exactly how our DBS systems are configured would be a good way to learn from each other and could be mutually beneficial. I hope you agree but please let me know if you don't. Okay, I'll go first. I think you'll find my system is a bit simpler than yours since I made a conscious effort to simplify my system about 2 yrs ago and I don't use any additional components: The center of my system is the Oppo-105 Bluray player. Once I was familiar with this unit's extensive versatility and excellent quality, I began to simplify. I removed my beloved VTL 2.5 tube preamp (with NOS Mullard tubes) because 2-ch music sounded just as sweet and dimensional using the Oppo alone as a preamp due to its excellent audio section. I then removed my Parasound AV-2500 surround processor because the Oppo's built in Dolby 5.1 decoder performed just as well. All channel outputs are run directly into 4 class D amps (the front L+R mains via XLR cables and all others via RCA). I bought the audio Kinesis 4 sub Debra distributed bass array system a few months after the Oppo. I run an RCA cable (with a single RCA connector on one end and dual RCA connectors on the other end) from the single sub output on the Oppo to the L+R inputs on the Debra's supplied 1,000 watt class A/B sub amp. This amp is a mono amp so all 4 4 ohm subs operate in mono mode in my system. I found I cannot perceive any differences between mono and stereo bass until the bass crossover frequency is set unusually high ( above about 150 hertz). The supplied sub amp has 'A' and 'B' sets of speaker outputs. I have the front 2 subs connected in parallel to the 'A' terminals and the rear 2 subs connected in parallel to the 'B' terminals. The Oppo has a configuration menu that allows for the on-screen setup of the following: Speaker Size- Each speaker is entered as either 'Small' or 'Large'. All 'Small" designated speakers have their bass augmented from the subs while all designated as 'Large' receive no bass augmentation. Speaker Level Matching- This allows the matching of each channel's relative volume or setting to other preferred levels. A system generated tone is played and the user cycles through each channel. The Speaker Size (large or small), speaker volume (from -10.00 db to +10.00 db in increments of .5 db), and distance from the listening position (from 0 to 60 ft in .25 ft increments for delays) are all set in this section. This Speaker Level Matching section also includes settings for the relative volume of the bass in this section. There is also a volume control on the Debra amp that can be manually adjusted for fine tuning the desired bass level of the 4 subs. Sub crossover frequency- This allows the setting of a frequency (from 40 to 250 hertz in increments of 10 hertz) at which all bass frequencies at or below this hertz number are sent to the subs. I usually select a 40 hertz cutoff for 2-ch music and ia bit higher for HT. After completing the rather extensive progressive setup procedure for the precise positioning of each sub, the above describes the total extent of system configuration required. I use absolutely no room treatments, microphones, sound meters, room analyzing/correcting software, DSP, tone controls or equalizers. The system Master Volume is controlled through the Oppo's internal 32 bit digital volume control that is accessible either through the Oppo's front panel or supplied remote. I doubt this volume control is as precise as the 1 db changes the Bent volume control is capable of but it is capable of small changes in volume. I hope this helped you understand how relatively simply my system functions. Please let me know your thoughts and let me know in more detail how your system functions. Thanks, Tim |
Hi enginedr1960, It sounds like you have a combo system, as I do, used for both music and HT. I was a bit surprised you use VTL 100 mono-block amps in your system. I would imagine they're great for music but less than ideal for HT since tube wear is increased. Or, do you have your system configured to utilize separate solid-state amps for HT duties. Could you clarify this? I understand how your Outlaw pre-pro is used for decoding surround sound codecs for HT. But I'm not certain how you utilize the DSPeaker antimode 2.0 and exactly what it does. Could you explain in more detail how your DSP controlled stereo bass works? I've been trying to spread the word on distributed bass arrays using 4 subs here on Audiogon ever since I personally discovered how well it has improved bass reproduction in my system. After a lot of research, I intellectually understand the acoustical physics and the theories on how and why it works. But I still think there is no substitute for auditioning a good DBA in person for appreciating how impressively it reproduces bass in any room without the use of mics, room analyzing/room correcting software, equalizers or room treatments. Based on the large number of posts I've read from members who seem to think their system bass response needs can be solved if they just get the right brand or model of sub, it's fairly obvious that many are unaware of the DBA concept. You're actually one of the first Audiogon members I've encountered thus far that also utilizes a DBA. I'm glad we're now aware we both use slightly different DBAs and can share experiences and information with each other. Thanks, Tim |
Hi Doc, I like your commitment to all out sound quality by using your tube VTL 100s for both 2 channel and HT. I just have a few questions: 1. Have you tried lowering the sub crossover frequency closer to the 50 hz lower frequency cutoff on your amps? DSPeaker room correction for 500 hz and down seems somewhat high and broad to me. I consider 500 hz to be in the lower mid-range spectrum rather than the bass spectrum. 2. Have you tried running your system with all room correction units removed? I think you'll find your system's bass response will be very good without it. I would recommend setting each of your sub's crossover setting initially at 60 hz and then experimenting with even lower settings of 50 or even 40 hz. A setting of 50 hz may not be good in your room due to your room having a frequency bump @ 50 hz. The downsize of this approach is that the level and cutoff freq. would need to be set individually for each sub. But this should only need to be done once at the precise setup/calibration stage. Thanks, Tim |
Hi Doc, I believe you live in a Manhattan postage stamp so lack of space and the need to listen at lower volumes are issues. I hear the penthouse at Trump Towers may be available soon. Just something to consider if you want more room, fewer neighbors and solid gold toilets. I now understand you use your DSPeaker for 600 hz and below system wide. The upper range of this (specifically 50 -600 hz) is reproduced by your main Ohm Walsh speakers and not your subs; you run your subs in stereo with the front 2 subs handling 60 hz and lower and the rear 2 subs handling 45 hz and lower. I think you're aware that there is some overlap with both your front 2 subs and your main speakers reproducing frequencies between 50-60 hz. But your DSPeaker likely adjusts output in this small range to smooth out response. Your clarification now makes your system a lot more sensible to me. My goal is mainly to learn how your system functions and not to criticize a configuration that obviously works so well for you. I know it's not easy to construct a system that sounds good at lower volumes. It's been well known for decades that human perceived loudness of very low and very high frequencies, in comparison to mid-range frequencies, decreases as volume is decreased. This was the reason some older audio components (1980s to 90s) had 'loudness' buttons and controls that boosted these frequencies to compensate. Perhaps the reason your system sounds so good to you at lower volumes is because your DSPeaker incorporates a 'loudness countour' that is boosting the lowest and highest frequencies relative to the mid-range frequencies as you lower the overall volume of your system. This is only speculation on my part but I think it's a reasonable assumption given your results utilizing this DSP tool. Tim |
