Running one of the last pairs of Northcreek crossovers for B&W Matrix 801 S2 that George Short ever built. Had him build the very important woofer Zobel circuit for each speaker too. Huge improvement over factory. Consider myself very lucky and actually a little smart :)
How good is the crossover in your loudspeakers?
I just watched a Danny Richie YouTube video from three weeks ago (linked below). Danny is the owner/designer of GR Research, a company that caters to the DIY loudspeaker community. He designs and sells kits that contain the drivers and crossover schematics to his loudspeakers, to hi-fi enthusiasts who are willing and able to build their own enclosures (though he also has a few cabinet makers who will do it for you if you are willing to pay them to do so).
Danny has also designed crossovers for loudspeaker companies who lack his crossover design knowledge. In addition, he offers a service to consumers who, while liking some aspects of the sound of their loudspeakers, find some degree of fault in those loudspeakers, faults Danny offers to try to eliminate. Send Danny one of your loudspeakers, and he will free of charge do a complete evaluation of it's design. If his evaluation reveals design faults (almost always crossover related) he is able to cure, he offers a crossover upgrade kit as a product.
Some make the case that Danny will of course find fault in the designs of others, in an attempt to sell you one of his loudspeaker kits. A reasonable accusation, were it not for the fact that---for instance---in this particular video (an examination of an Eggleston model) Danny makes Eggleston an offer to drop into the company headquarters and help them correct the glaring faults he found in the crossover design of the Eggleston loudspeaker a customer sent him.
Even if you are skeptical---ESPECIALLY if you are---why not give the video a viewing? Like the loudspeaker evaluation, it's free.
https://youtu.be/1wF-DEEXv64?si=tmd6JI3DFBq8GAjK&t=1
And for owners of other loudspeakers, there are a number of other GR Research videos in which other models are evaluated.
174 responses Add your response
Imo and decades in audio and modding my equipment as well as ally Loudspeaker Xovers. Your speakers Xover on 85% of speakers is at best average my focal Sopra aat over $20 k have cheap. Xoverparts inductors instead of say a $$50 copper foil ,theyhave a $10 sledgehammer iron with wire wrapped around it Solen capacitors $3 resistors what a disgrace . i just bought a pair of Qualio ultra Loudspeakers under $23k land built better then $30k loudspeakers . Top notch Jantzen Copper foil waxed paper inductors Mundorf mid grade Evo aluminum foil oil for the Bass ,I had them upgrade to clarity latest Purity caps top mundorfwiringWBT connectors 3 sets of WBT connectors on top they include several sets of mundorfsupreme resistors to adjust. The Mundorf AMT tweeter to your room , then 2 ndset for your main amp for speaker ,Or 3 rd set to run a separate amplifier dedicated for the woofers this is what I did , you can run a med power tube amp on top and a moderate SS amp for the woofers . The only headache is now running in the Loudspeaker drivers and thesemuch bigger capacitors , ijust let it play for a week capacitors to an very much Taylor the sound. Ifi am not totally satisfied I will put in maybe Mundorf supreme silver oil , but pricy about $1400 for just 3 capacitors per speaker x2. Danny Ritchie knows what he is doing but uses not too much better then average parts vs what I use IMO Go to Humble homemade hifi capacitor test and ratings rom 7-15 for capacitors , many companies use cheap brass with thin gold plating . Copper is a 3x better conductor then brass which is too on the brighter side ,seen often in electronics everything in my system is gold overCopper do it right 1x and be done with it . |
On an Lpad, there are two floating wipers, but only one is shown in the schematics. We are using the other and it goes from ~11 to ~36 ohms before it opens completely. The circuit works best above ~18 ohms, hence R2, with ~20 ohms being near optimal. If you saw the frequency response of the JBL 2251J, the circuit would make more sense. I want to roll it off at about 2,500 Hz but that peak at ~3kHz makes this near impossible to do cleanly. I had to come up with some very imaginative thinking and a bit of luck from experimentation to make this work! What I do is to roll it off a bit earlier by "over capacitating" it. If you use too much capacitance in a second order low pass filter, you will greatly increase the slope but also create a hump just below the roll off point. The more capacitance, the bigger and lower the hump. The shape of the rising hump is obvious with the Lpad is turned full up (open). But I also let some of the signal pass through R1 or R2/VR1. This portion of the signal is NOT IN PHASE with the hump and the more you let through, the lower the hump becomes until you have a fairly smooth response up to the ~2,500 Hz roll off point. VR1 lets you selectively tune the hump. |
I find myself on the fence regarding modifying crossovers. One on hand, I purchased them for their sonic character so I’m resistant to change. On the other hand, I’m open to changes of certain speaker crossovers like Magnepan and Klipsch - maybe it’s because the outcome is more positively predictable by following the footsteps of others. |
How good are my crossovers? There are probably no others in the world that function as these do using these components and the parts selection has taken years of tweaking.
Caps were mixed for there "particular sound" and multiple values were mixed to as to produce the most common value (e.g., the higher of the two was always mixed with the lower of the two other caps when used in parallel).
|
I have restored a lot of speakers in my time including refurbishing crossovers. At times I have had 3 or 4 speakers of the same make and model all with quite different capacitor values due to varying degrees of aging and natural variability. Unless the values are way off [and I mean WAY off-like 50%out of value] they all sound much the same.That has surprised me.I have had to conclude that a fair degree of the sound relates to the drivers independent of what crossover components or values might be used.You certainly hear when drivers are not working properly. |
invalid1,283 posts @ned1000 how do you know Danny is right and Wilson is wrong.
|
@ned1000 how do you know Danny is right and Wilson is wrong. |
Danny Richie makes a point of stating that crossovers cannot be correctly done in simulated circuits, but only by using them with the intended drivers that are mounted in the intended enclosure, then doing acoustic measurements. Of course the crossover parts have to be matched left speaker to right, the matching being done electronically.
|
surely @bdp24: discrete capacitors and inductors can be represented in circuit simulator as RLC first/second/third order models, where R is ESR (equivalent series resistance), which in ideal capacitors/inductors is very low (TanD below ~0.01). high volume manufacturers use cheaper than ideal components, and count on ESR as “free” resistor in series with inductors/capacitors, which is added to actual resistors in mid/high legs of x-over circuit. replacing “so-so” performance capacitors and inductors in x-over circuit with excellent ones will increase resonances, if circuit is not recalculated and other related components not changed. saying that I am not against replacing aged/degraded components in x-over part, if you know what you are doing. |
as analog engineer, I would advise to be careful to just switch existing x-over components w/ “better” ones, because in many speaker designs x-over components parasitics are counted in speaker’s design optimization process. in my speaker design flow I characterize driver, inside actual cabinet w/ damping materials, by measuring complex impedance vs. frequency at desired power, and then I create RLC model for my circuit simulator, used for design new “perfect” x-over circuit. |
@zx10 The route you have taken is a growing trend and one methodology for using a Speaker that is worthwhile making the time for, to have it known about in a location where there is a broader audience. A Speaker Model that has been used for this type of refurbishment with the end result being similar to your own, being a modern Xover Design built with Modern Components when Interfaced to a Olden Speaker Design brings exceptional results. Myself I endorse this type of activity for two reasons, but my first reason is not exactly audio related, it more aligned to being active by doing less to encourage less CO2 release. I am a Advocate of and Adopter of, being proactive in what is referred to in todays world as the Circular Economy. My second reason is that designs from a particular era have been invested in quite healthily for the Parts that are able to be seen by the Purchaser, but under the hood, where concealment is the advantageous condition created, costings awarded to produce the Parts that are concealed have been scrimped on as a BOM and the concealment has been very very deliberate. Why not at another time when Warranty Issues are over and other ideas are surfacing as a result of being inquisitive, spend a little time to Ponder how it might be if one was to couple to Quality Speaker Drive Units used from a past era of production, the most modern electrical parts and design concept for the Xover Interface. Additionally, why let cost be the constraint, if $400 - $1500 is the costing for BOM of selected Parts and is inclusive of the cost of assembly of the electronics, then as a comparison to other options, this one is looing to be well within the boundaries of VFM. What happens when the outcome of following through on such a methodology to experience something new from a Speaker, produces a Speaker that really does make a discernible change for the better, when using recollection if Olden Speaker Design to New Design for assessing the end sound. With better as the outcome, then what is the issue there are plenty of positives and wins with adopting this method. A comparative Updated Speaker Design from certain Brands or a Build produced in recent times can easily be costing 400% - 2000% Increase in cost to own the Speaker as a current New Purchase. The Purchase comes with the unavoidable added condition, where after approx' 18 months - 30 months there will be seen a depreciation of Value of the Purchase by 30% - 50%. In relation to the Speaker Model JBL L-100T, this model is replaceable currently with a Modern Design being the L100 Classic MkII. The Classic Mk II is going to cost the best part of $4K as a New Purchase and approx' 40% less as Used Item Purchase ($2.6K) The Owned 100T Speakers, were most likely purchased in 1986 @ approx' $1K. $1K over the the 40 Years owned are actually costing $25 per year or $00.50c per week, which is great VFM, and in relation to the method used to make changes to the Speakers by zx10, there are other bonuses. Bonus No1, Great VFM has been attained from the original purchase, especially with the outcome the Speaker are remaining wanted to be kept in daily use - Bonus No 2, The Owner of the Speaker, knows every day of the Upgraded Donor Speakers usage History - Bonus No 3, The Most Recent Xover Upgrade, is one that is producing a Bespoke Design for this Speaker and as a design it is highly likely the end design will be a challenge for the latest 100 Model to show where it is the better producer of an end sound. As an investigator of Build Costs for Speakers, as having a commission built Speaker is an interest of mine. I am familiar (not expert) on costs of a small range of Drivers. From the 80's / 90's Drivers built to a High Spec' can easily be costed in todays monies at $2K to $4K if a set of 6 x equivalent drivers are being selected for a BOM. I have seen on a few Build Topics for Speakers, where the guidance is for a Particular Model of Speaker, where a Modern Tweeter to be used in place of a Original Tweeter that is Shot, or being suggested as an Upgrade Tweeter for a Olden Design Speaker where the Pair of Tweeters being suggested are to cost as a New Part, the best part of $1K. If an individual is in the fortunate position to have the set up in the listening space, where the Speakers are Coupled to the Room, where the energies produced from the Sound are managed to the point the energies are not interfering negatively with the Produced Sound. In conjunction with the management of Produced Sound, if the system can produce a Signal that is of the quality when it arrives at the Speaker Xover it is unadulterated. It makes absolute sense that a improved electronics selected for the Xover, can add further attraction for the end sound that is being produced as the result of the changes made. As stated in an earlier Post: "Coupling a Speaker to a room is the way forward to create a confidence the speaker interacts at its best when transmitting sound through the physical structure of the room, including the floor, walls, ceiling and locally placed items. The Speaker / Room Interaction can have a profound effect that is a negative impact on the quality of the sound being transferred. Creating effects like room modes (standing waves), Reflected Sound, Causing Local Placed Materials to produce sound. Each when being generated will be negatively affecting the overall acoustic characteristics of the room. Xovers design does not do anything to alleviate the above influences on produced sound."
|
When I chose my most recent speaker I watched a you tube video by the designer. He described the country origin of the components. Nice tweeter made to their spec , nice woofer made for them by Morel , but the nicest looking part inside was the crossover. It looked really high quality. Looked like it belonged in a more expensive speaker. |
Purchased a pair of JBL L-100T's in 1986 when I saw them on the cover of Stereo Review in the spring. Had them gone thru and woofers refoamed couple of years ago by an old retired JBL guy in Ca. I used to live in Northridge about 2 mi. from where the JBL company was years ago. Always liked the speakers but the highs were just a bit bright. I noticed an ad on Ebay for the Crossover Chef. He makes upgraded crossovers for 30 or more speakers and all the vintage JBL's. They cost $400 with shipping and the guy is slammed , took 3 months to get them. Had a tech help me install them , they are twice the size of the originals about 2 months ago. Just amazing really , I am astounded. More bass , still tight and not muddy , the mid range is smoother and the high's are no longer too bright. I drive them with a McIntosh MA 7900 integrated amp 200 wpc into 8 ohms. Know I sound like a commercial for this dude but one of the best investments I've ever made. |
@bmbmzig: Danny Richie has repeated stated that achieving a desired frequency response (the specs/measurements to which you refer) does only one thing: make the speaker accurate. He over and over has stressed the point that replacing sound-degrading crossover parts with parts that don’t degrade the signal is the way to increase a loudspeaker’s transparency, resolution, fine detail, soundstage layering (depth, width, height, spacing between singers and musicians), and other audiophile performance characteristics. For the speakers sent to him that have technical problems (less than optimum crossovers), he designs a new crossover to correct those technical shortcomings. And he also of course builds the new crossover using parts he has found produce good sonic results For the speakers that already have an accurate frequency response, he just replicates the stock crossover, but replaces the electrolytic capacitors, sand cast resistors, and iron core inductors with audiophile grade parts, including internal wiring, copper binding posts, etc. People often say (in fact did so just above) "Why not just buy a better loudspeaker, one you like the sound of more?" That’s fine, but what makes you think the better speaker doesn’t also have a "junk" crossover. All loudspeakers are built to a price point, and using the best crossover parts can increase the cost of a speaker to the point of it not being a commercially viable product. Loudspeaker companies don’t divulge what parts they use in the crossovers, and Wilson Audio "pots" their crossovers so that you can see what’s in them. The video below---Danny’s latest, posted just yesterday---is an interesting (and unique) case. An owner of a Magnepan 2.6 sent his speakers to Magnepan to have them repaired and refurbished (details in the video). When that was completed he had Magnepan ship the speakers to GR Research, Yes, Magnepan is well aware of the mods Danny offers for their speakers. To hear Danny’s thoughts on the 2.6 (and Magnepan’s in general), you can watch the video. So if you’re a Magnepan lover, how do you take the advice others have made in this thread, and just buy a speaker whose sound you like more than Maggies? Like what? A "better" model Maggie? Sorry, they all contain the same quality crossovers. At least they did until recently. Magnepan themselves now offer some of their models in the new X Series, which feature crossovers using better parts, internal wiring, binding posts, etc. And what if you like your current speaker more than any other in it’s price range, but suspect that an upgraded crossover will keep it’s basic sound character, but improve it in the ways I listed in an above paragraph? A GR Research mod is just one alternate to consider.
Yesterday’s GR Research YouTube video is entitled "Is This The Best Deal In High-End Audio? (Magnepan + Mods). It may be, but it has stiff competition from the Eminent Technology LFT-8b, another planar-magnetic loudspeaker. Here’s the video:
https://youtu.be/WjNV8BbZRG8?si=HyRoyMQiMGXhWe1Y
And here’s a video on the ET LFT-8b:
https://youtu.be/Uc5O5T1UHkE?si=yyvaTIj9e-Rc44JL
|
I haven't watched Danny's videos religiously so I don't know what he's left out. In any case one shouldn't rely on only one source for their information. Sometimes I forget others far newer to high end audio, I've learned from so many sources over the decades.
As it pertains to speaker mods, so much more goes into the final result such that a one solution mod or speaker not possible. One should realize another person's modifications may not work in their system, room, or be sympathetic with their perception of sound qualities. |
The one thing that I find interesting is it is all about spec’s (measurements). He talks about frequency response, impedance, etc, which are indeed important, but I have found spec’s don’t tell the whole story and you have to use your ears to make your choices. Sound is subjective, and what I like, others may not and vice versa. The other issue I have is the interaction of specs. Let’s just use frequency response and impedance. The two interact but he’s not talking about that, and I’m not sure you can relate a correlation of the two as to how it affects sound. Bottom like, if he can make a living doing what he does, and people are willing to pay for his services and knowledge, and they are happy with the results, more power to everyone. I agree with what has been said, By the sound you like from the start, not something you have to have altered to get there. |
Modifying audio components in general allows one to obtain exactly the results one desires, this presumes one knows exactly what they're seeking. Understanding how to achieve those results requires either the assistance of others who have specific knowledge and/or much experimentation. In the case of my Klipschorns there has been much knowledge accumulated over many decades, I relied on others for a pathway and then applied my own unique mods, result is I finally have my end game speaker.
My perspective on active vs passive, active is a science, passive is an art. Mods have always been about art for me, I rely on others to provide me with the science, my unique mods conform with good science. Passive mods is art in the sense one can find the perfect recipe via various combinations of high end caps, resistors, inductors, each which may have unique sonic qualities.
Danny provides both a general understanding and/or model specific guideline for speaker modifications. Funny how some think this is a disservice when in fact he's handing out research and knowledge free of charge, he's not requiring one to make purchase. |
"Why should I upgrade when I can buy a better speaker?"
That is the title of a video Danny Richie posted a year ago, one I missed. It may answer some of the questions raised in this thread. Here it is:
https://youtu.be/kSOlxLvSR58?si=lE8ci1BobAp2g1QX
|
The original topic posed was clearly focused on passive crossovers. Off topic, active crossover as an alternative to passive opinion was introduced and you started pontificating about their unquestionable superiority
Going down that path demands more than just saying it is so. Yeah, a good start is objective measurements that provide proof of superior sound quality to justify first of all the additional cost. |
So if I took a $5000 speaker and used the exact same design but used film capacitors instead of polypropylene capacitors, would I hear a difference in the sound? Same question but change the dollar amount spent on the parts. Say the $500 crossover is replaced with a $5000 one. Would I hear a difference? And lastly if I redesigned the crossover completely with different numbers and slopes. Would I hear a difference? The answer is the same to all three questions.
Maybe. |
I don't know if timbre has been raised as an issue, my sole issue with active crossovers is they would necessarily alter timbre. I've chosen specific components and modified parts within some components in order to achieve a pleasing timbre. I exclusively run SET amps and SET pre, no way do I want to introduce a SS active crossover to this. |
@phusis +1 Mike |
@phusis "Practically speaking the only trade-off with active is a higher electrical bill from the multitude of amps. " active x-over could actually save power and deliver higher SQ than passive one, by enabling mixing D (low/sub) and A (mid/high) class amps in one system. mids/highs don’t need more than 10W in regular listening, thus low power class A amps should work. in addition, active x-overs improve mid/high driver damping factor, which is typically. killed by resistive inductors and actual resistors in passive x-over circuit. |
@texbychoice wrote:
Now suddenly measurements are a convenient step (i.e.: "Measurements do not tell the entire story")? Apart from perceived listening impressions (they still count, don’t they?), you have a purer ohm load when an amp channel (a dedicated one, no less) is looking directly into a driver’s terminals, avoiding the likelihood of large impedance swings and steep phase angles through a passive crossover and hereby providing for much better working conditions for an amplifier, with better driver control and lower distortion to follow.
There’s no "case for all active" to universally go by. Why would you impose specific terms for active to make sense, other than the potential for better sound quality or to whomever it applies? That’s on you, pal. The case for active, from my chair, is sound quality via outboard active configuration and high efficiency speakers where size, by and large, isn’t an issue. Whatever it takes, it takes. For others it may be convenience, simplicity (yes, you heard me right), small size, and even an overall lower price with a bundled, preassembled and -designed package. The good thing about active is that of being able to make more efficient use of a given amplifiers performance envelope, and thus you can save money per unit and keep yourself from buying overbuilt, hugely expensive amps that would otherwise be needed with passively configured, heavy speaker loads. So, what may seem to be more expensive with the need for more amp channels actively to begin with, can turn out to be much less so than expected or even save you money eventually. The sleep remark was hardly to be taken in the literal sense, but merely a play on words to address your claimed issue with reliability.
You’re making a problem where there needn’t be any. Added amp channels and a DSP in themselves don’t necessarily equate into introducing a weak link. Buying a cheaper, bundled active package on the other hand (not least subs with built-in plate amps) can be an issue where reliability goes, but as I pointed to earlier my advocacy is outboard active config., and this way any quality gear can be in the loop for a purchase decision, where reliability is no bigger issue than it is passively.
Says who? Why don’t you get your head around the fact that some, if not many of us actually pursue active from a sound quality measure first and foremost, without "cheaper and easier" being part of the primary incentive?
Oh I do make my own system as I see fit. I hope you do too. We’re debating crossovers here, and I added my experience with a way to implement them to make their presence less of an issue in the signal path. Please note that amp to driver interfacing is but one part of many to be considered. I’m not implying it’s a ticket that in itself makes everything else magically fall into place, nor do I mean to impose my views on others. |
My experience is based on LS3/5as. I had an original Rogers 11ohm pair with it's fairly complicated crossover. When the Cicable external crossovers came out for them I bought them and removed the internal crossovers - I also replaced the cabinets with thinner walled ones (9mm instead of 12mm like in the original Kingswood Warren built prototypes) so that might muddy the picture slightly. The Cicables were designed by Derek Hughes, who used to run Spendor and learnt his craft from his father (designer of the BC-1) and at the BBC, and has since designed all of Graham Audios and Stirling Broadcasts speakers and a passive speaker system in the Royal Opera House in London, which is very unusual as such systems are normally active. The crossovers use expensive inductors and caps from Mundorf and at points reduce the THD of the LS3/5a by about 40%. The difference is stark - much more transparent with more detail and much smoother. Derek apparently doesn't just implement the standard type of crossover curves, he considers the driver characteristics more - there are interviews with him on YT where he mentions this more. Derek designed the Stiring Broadcast V2 LS3/5a when Kef stopped making the LS3/5a drive units, which use modern drivers from SEAS and Scanspeak. The crossovers for these are less complicated than the originals. They sound good but not as good as the Cicable crossovers which is not surprising considering the price point they were designed for. Later they produced the V3 version which is basically the same crossover but with the iron-cored inductors replaced with large air-cored ones. These are more transparent and detailed, closer to the Cicables, but there is a 'shizzle' to the upper end, maybe exposing some of the THD in the original V2 crossover and it's more basic components. Now there is a V3.2 version which has a more boutique crossover which is handbuilt by Derek, or his daughter who works at Audionote). Components are Jantzen air-cored inductors and Crosscap capacitors. Again another step up from the V3. I also have some Xtracable external crossovers, also by Derek H, for my V2s and they are again slightly better than the v3.2s - also using expensive Mundorf components. This progression in sound quality is whilst using the same cabinets and drivers, so clearly isolated. Lastly they had a bass extender called the AB-2 which used a band pass conenction to the LS3/5as with a sinlge 15mH iron cored inductor with a 220uF electrolytic and 6.8uF bypass polyprop capacitor per channel. With the v3 or v3.2 connected via the band pass there was a loss of audio quality, often seen with a reduction in the soundstage. Replacing theses AB-2 crossovers with a Jantzen air-cored inductor and Jantzen crosscap or Mundorf Evo Oil caps completely stops this loss of audio quality, most easily seen in a retention of the soundstage. The bass is also very slightly better but limited by the nature of the AB-2 bass extender. Commercial speakers have crossovers that are very much price constrained compared to what Danny does. The v3.2s that Stirling are doing are using crossovers that are quite expensive and not commercially sensible, but they are closing down and it is only because of that and that there is an LS3/5a enthusiast building them (me) that they exist. If you were to buy a commercial LS3/5a with a crossover that expensive you would be looking at several times their cost. Same with those AB-2 crossovers, about £480 in parts alone. Worth it to me and a few LS3/5a nutters that have signed up for them, but not commercially viable.
|
Yes, this thread started (and has largely remained) a discussion about loudspeaker crossovers. But now that the subject of open baffle subs has come up (I accept the blame for that All the open baffle speakers on the market (at least all those I am aware of) have the speaker’s drivers---including the woofer---mounted on a flat baffle, the baffle then mounted on a base. It is common knowledge that one of the penalties of eliminating a sealed or ported enclosure for a woofer is the resulting dipole cancellation phenomenon: without an enclosure to separate the front and rear waves of a woofer, those waves "wrap" around the open baffle on it’s two sides (and top, for that matter), the positive (forward) and negative (rearward) waves meeting on the baffle’s sides (and top), that meeting resulting in a drop off in bass response (+1 plus -1 = 0). The frequency at which drop off begins is determined by the dimensions of the baffle. The bigger the baffle, the lower the frequency.at which drop off begins (if the baffle is big enough---like the woofer mounted in a wall---it becomes an infinite baffle woofer. A subject for a different thread). What the W/M and H open baffle "frames" do is increase the distance between the front and rear of the woofer(s), thereby lowering the frequency at which drop off begins. However, if the enclosed space created by adding side and top panels to a flat baffle is deep enough, a "cavity resonance" is created, which we don’t want. The open baffle frames used by Rythmik/GR Research and Linkwitz are all about 14 to 16 inches in depth, which provides a healthy amount of front-to-rear woofer separation (thereby lowering the frequency at which dipole cancellation commences) while avoiding a cavity resonance within the passband of the woofer system. Ergo, no penalty to the open baffle sound, with only positive benefits. Another benefit is that the added side and top panels provide increased baffle structural stiffness, hence decreased resonance from an unsupported front baffle. In addition, Brian Ding installs a dipole cancellation compensation circuit in the plate amp (Rythmik model A370) that comes with the OB/Dipole Woofer kit (I believe it is a simple 1st-order/100Hz filter, the filter boosting frequencies below 100Hz at a rate of 6dB per octave). The only people who poo-poo the OB/Dipole Woofer system are those who have not heard it. A Rythmik Audio/GR Research OB/Dipole Servo-Feedback Subwoofer fanboy? Oh, you betcha!
|
Oops. In my directly-above post, I referred to two styles of frames used in open baffle woofers/subs: the W style, and the M. Actually, W and M are used interchangeably, M merely being an upside-down W. The correct nomenclature for the second style frame is "H". The W/M and H style frames each have their own advantages and disadvantages, but are basically equal in performance and sound quality potential. One advantage of the H style is that it is preferable for a 3-woofer sub, as the W/M is really limited to two woofers. If you look at a diagram or photo of the W/M style frame, the reason for that becomes obvious. AudiogoN member jaytor has a pair of 2-woofer Rythmik/GR Research OB/Dipole Subs (stacked) standing aside each of his GR Research Line Force loudspeakers, with two woofers facing forward, two rearward. The Line Source is comprised of planar-magnetic midrange and tweeter drivers, with some very serious passive crossovers. Check out his virtual system listing for pics. Look at the size of those Miflex caps!
|
@texbychoice: Your post brought to mind one other consideration in the passive vs. active crossover matter, one Danny brought up in his video. It is this fact: With a passive x/o installed (almost always) inside the speaker enclosure, to replace the (almost universally used) electrolytic capacitors with high quality film or foil caps will require two things: a lot of money, and a lot of space. The latter type of caps are much, much larger than the former, often too large to be installed inside the speaker enclosure. And the cost of a group of caps (large enough in value to equal the value of the stock electrolytic) can be ridiculously expensive, in some cases more than the cost of a good electronic x/o. One project Danny did was to replace the active x/o that came with the very fine Linkwitz LX521.4 loudspeaker with a passive x/o. That was no small feat, as the 521 is a 4-way design (the stock speaker requiring four stereo power amps!). By the way, the 521 features an OB/Dipole sub, very similar to the one offered by Rythmik Audio and GR Research. Linkwitz built his OB frame in the "W" style (as did I), while GRR offers plans for both W and M style OB frames for their DIY kit. GRR also has a cabinet maker who offers a really good M frame, available both in flat pack DIY form, or fully built. The best subwoofer on the market? For use with dipole loudspeakers, I say yes! So did Siegfried Linkwitz. Another by-the-way: Linkwitz---like Danny Richie---designed his speakers to have flat measured on-axis and off-axis frequency response.
|
Having an end sound produced in a unique environment that is being identified as not able to produce an impression that has an appeal can be the result of more than a Xover design and accusation the Xover design needs improvement. A Speaker is typically designed in a very disciplined manner and in conjunction with control measures, where the ambient space the Speaker is used in during the design stages through to final design is quite different from a ambient space a Purchased Speaker will reside in while used. Every Speaker Produced and Sold from a particular model, is to become a Speaker that has its own unique interpretation of its end sound produced. Each unique space the speaker is set up in for its period of residence, will have its own unique voicing for the end sound. The energies produced by the Drivers and sent in to the Ambient Space is going to produce a unique sound scape within each space the Drivers and Cabinet are used in. The source of a sound heard should not be detectable, and that is not suggesting it is only the Speakers Form and placement in the space that should not be identifiable. Energy Transferred as Sound can have pin point locations identified where it is reflected from or unsettles the structures within the room. Xover design is not going to remove certain frequencies that are not being managed well within the room, unless the Xover is a design that removes those frequencies from the Frequency Range of the Speaker. The Space selected for the Speaker and the Speaker within the selected space, needs to be worked with to find something that represents a optimised interface / coupling to each other. Coupling a Speaker to a room is the way forward to create a confidence the speaker interacts at its best when transmitting sound through the physical structure of the room, including the floor, walls, ceiling and locally placed items. The Speaker / Room Interaction can have a profound effect that is a negative impact on the quality of the sound being transferred. Creating effects like room modes (standing waves), Reflected Sound, Causing Local Placed Materials to produce sound. Each when being generated will be negatively affecting the overall acoustic characteristics of the room. Xovers design does not do anything to alleviate the above influences on produced sound. The good news being that putting measures in place to tidy up the Speakers Coupling to the Room are not necessarily expensive, bit do need a little creativity if the decor and aesthetic for the Space supplied for the Speaker is to be maintained to a particular appeal. An acoustic fabric might need to be dyed to color match a wall color. An Absorption Panel, may have a dimension that matches a Wall Art Picture that can then be mounted on to the absorption panel. Diffusers are able to be found that look like a Sculpture and be a feature in a room, or a cheaper version is able to be sourced / produced that again can be blended to the room color or concealed behind a fabric. Where the interesting area is to be found is the impact of the siting within the room for such ancillaries to assist with managing energy transfer into the Space. |
@devinplombier Wrote:
A bit of history for the fun of it, the first powered and analog active speakers were from JBL1960-64 Hartsfield and Paragon see here, here and here. Mike |
There are two very different implementations of non-passively crossovered speakers. - Active-crossovered speakers like @phusis discussed necessitate each driver be individually amplified and controlled by a line-level crossover, which may be either digital (and usually implementing some sort of DSP), or analog (e g. Linkwitz). Although passive crossovers are eliminated, this type of setup is going to require intentionality and be more complex / costly than the same, passive-crossovered speakers. A pair of 3-way speakers will require at the very least three stereo amps or six monoblocks and one active crossover. 4-way will require 8 monoblocks, etc. The system will require a fair amount of design and setup work and the attendent skills. Reliability shouldn't be any more of an issue than with any other electronics. But an active-crossovered system will surely sound better than the same, passive-crossovered one - quite a bit better; but there probably are better choices for folks who value tried-and-true simplicity - Active speakers are entirely different. They too feature individual driver amplification and a line level digital crossover and DSP (I'm not aware of any analog active speakers), but all the components are integrated in just two, conventional-looking speaker cabinets. All a person need do is plug them in the wall, connect a source, press play, and they're ready to go. All the component matching and integration has already been done and optimized by the manufacturer. I auditioned Dutch&Dutch 8c, which fall in the latter category, and they sound fantastic. I think they retail for $18K (?), which is actually quite reasonable when you consider that they effectively replace amps, preamp, DAC, and sometimes streamer. These are perfect for folks who desire a streamlined system of the highest quality, but prize convenience over control. These are only broad outlines. There are multiple other considerations, of which there are pros and cons of course 🙂
|
Wins in what specific technical and measurable ways? Trade offs must be honestly identified and considered. That is the only damn fact that matters.
Buy two more similar amps for 3 way setup, eh? So say I have a quality 100 Watt amp, so buy two more that would add several hundred dollars of cost. That is a hypothetical that makes no sense to support the case for all active. Conflating potential reliability facts with trouble sleeping is an illogical comparison. The more complexity is added, the more the entire system is at the mercy of the weakest link. Cheap out on any item and the entire system does not achieve it's potential. The core premise of active being cheaper, easier, better completely fails. Pick any 2. You can't have all 3. Do your system as you see fit. Personal preference extrapolated to claims based on broad generalization does not equate to a clear path for all to duplicate.
|
@texbychoice wrote:
Nothing new here (either).
Right; active config. is nothing new nor revolutionary (nor is passive bi-, tri- or more-amping over speakers with existing passive crossovers, albeit a more well-known approach among audiophiles), but you could say that of other design choices that, while advantageous, are not generally implemented. Practically speaking the only trade-off with active is a higher electrical bill from the multitude of amps.
True, but with a proviso: there aren’t that many opportunities to make an apples-to-apples comparison between actively and passively configured speakers, because it’s about assessing a typically bundled active speaker design of one particular brand (usually with built-in Class D amps and a consideration for minimizing cost here) with a passive speaker design of another brand with a wildly varying combination of amp choices. Basically you’re left with buying into comparing completely different scenarios that aren’t that easily comparable coming down to a single aspect alone. To really assess the potential of active config. take the same speakers, strip them of their passive crossovers, add the required amp channels using a similar amp as the one used passively as a basis, add a high quality DSP, and have fully optimized filter settings implemented, aided by measurements and completed by ears from your preferred listening position. Then you’ll have a more true bearing, and in each of these cases and specific context where I’ve heard this happen, the active approach - not only to my ears - won by a mile, hands down. And what do I mean by "won by a mile"? A much better resolved, more dynamically astute, more transparent, more transiently clean/less smeared, more effortless, and tonally a more accurate and authentic presentation. Besides: my main intention was to point at the amp to driver interfacing, and how active wins out every day here. This is not debatable - indeed it’s a damn fact. With any design however there are many choices to be made, and the totality of those will determine the outcome. My advocacy is for outboard active configuration, because this way you can go about it more or less as you see fit - like you would passively. If however a preassembled and -designed bundled active speaker fits your bill and hits a home run, then you may have come by your solution all that much easier.
Come on. Let’s say you buy two more power amps similar to the one you already own for a 3-way active setup, add a high quality DSP (while stripping the passive crossover) and some extra IC’s and power cables - you mean to tell me you’d now have trouble sleeping because of reliability issues? Well, if you insist on placing obstacles in front of you to avoid going active or otherwise adding a few components (or just to be willful), by all means. But essentially the same could be leveled at those who’re buying a turntable with all that involves, a separate preamp, mono block amps or other. Like you said, measurements don’t reveal everything, and the same way holding a rigid stance on component count and how it pertains to sound quality and reliability can’t ever be the whole story. |
Well maybe with Magnepan speakers but otherwise the statement is misleading. I've heard a number of implementations of dipole speakers with sealed and ported woofers and in those instances it was clear the combination can work.
|
@bdp24 Very well said summary. For a DIY person crossover modifications or going the amp for each driver route would not be difficult. If one can't handle a soldering iron, stay away from DIY. Passive crossover or all active can result in a system that measures well. Measurements do not tell the entire story. For those of us that have over the years tried many of the latest bright shiny audio gizmos or idea we know that fact all too well. Separate amps for each driver is nothing new and revolutionary. There are trade-offs for any approach. Claiming an all active system to be superior is a broad generalization, not a universal truth. Previously noted potential problems cannot be explained away by opinion. Parts count increased by dozens and more interconnections decrease overall reliability and introduce new variables. That is engineering fact that can be calculated. When a complex system works it can be great. When a problem appears, it can be a nightmare.
|
For about a week I’ve been down with a serious bout of a rare form of migraine headache known as a "cluster" headache (I started getting them forty years ago). Imagine getting a bolt of lightning to your brain, and waiting for the next one to hit. Sometimes it’s in a matter of seconds, other times minutes. My clusters usually last about three days (most often starting just above one ear, making it’s way across my head to the other ear), this time the longest ever. The prescription drug I take usually helps, but this time didn’t. People have been known to commit suicide to end the pain of their clusters. Anyway, catching up with this thread has been for the most part delightful; lots of great comments from knowledgeable, informed audiophiles. As for the others, oh well. As others have already said, upgrading the crossover in your loudspeakers can be done without resorting to buying a kit from GR Research. And if you like a deep hole in the frequency response they may produce (due to two drivers being out-of-phase at the x/o point, or as in the original version of many of the Klipsch models, the woofer and tweeter not even reaching each other until their respective outputs have dropped way below the mean response of the speaker), that is of course your right. But to call that defect a "voicing choice" is just silly. What it really is, is poor engineering. Klipsch corrected the poor x/o filters in the Mk.2 versions of some models. That is not a matter of a natural evolution (or tighter parts values control), it is correcting a mistake. It was obviously done in response to Danny Richie’s evaluations. There is no doubt that Magnepan’s introduction of the X Series versions of their models was also made in response to Danny Ruchie’s evaluation of a few models. I mean, Magnepan has been making all their models with the same crossovers since 1970, the X Series upgrade appearing only after Danny’s videos aired. Here’s something to consider: I don’t know the prices, but it could be that the GR Research upgrade kit for the, say, Magnepan 3.7i, might be about the same price as the cost to get the X Series version instead of the standard 3.7i. But here’s the deal: Magnepan uses all better parts in the X crossover, but the x/o filter characteristics are no different from those in the standard model. It in no way "corrects" the problems Danny Richie found in his examination of the 3.7i. What problems, you ask? The same problems John Atkinson found in the last Stereophile review of a Magnepan he did, decades ago. Magnepan has never sent another speaker to the mag, Wendell Diller saying it was because Magnepan’s can’t be measured like other speakers. Both Atkinson and Richie found the drivers played "over each other", a result of the shallow x/o filters and the chosen crossover frequencies. That creates serious problems of comb filtering, a phenomenon known to speaker designers for many, many years. It’s a testament to the quality of the Magnepan planar-magnetic drivers that the speakers sound as good as they do in spite of the flaws in their crossovers! The beauty of the old Maggies (like the 3.6) is their series crossovers. With a good active crossover (like the First Watt B4 I mentioned earlier), you can create your own filters. I don’t remember what filter characteristics Danny came up with for the 3.7, but with a x/o like the B4 you can try 4th-order low- and hi-pass filters at 400 Hz. If you don’t like it, try something else. Or, you can just buy a pair of Eminent Technology LFT-8c’s. A single push/pull planar-magnetic driver (magnets on both sides of the Mylar diaphragm) for 180Hz up to 10kHz, a ribbon tweeter for 10kHz up, and a dipole woofer for 180Hz down. Wendell Diller has been insisting forever that a monopole woofer "does not work" with a dipole loudspeaker, and Magnepan has been working on a dipole woofer system for a number of years. Why so long? No need to wait any longer, Eminent Technology already has one. Or even better, add to your dipole loudspeakers a pair of the unique OB/Dipole Servo-Feedback Woofer that Brian Ding of Rythmik Audio and Danny Richie collaborated on. Open Baffle (2 or 3 12" woofers in an open baffle frame), dipole output, and servo-feedback control of the woofers. It will play up to 300Hz, unique for a sub. It comes with a plate amp that contains a dipole cancellation compensation circuit, and all the controls you want and need, and in the analogue domain.
|
"The $27,900 disappointment? Wilson Audio Watt Puppy 8 issues..."
), here’s something that hasn’t yet been mentioned regarding them.
