A Discussion About What Level Of Analog To Stop At

@neonknight 

You have done a great job so far. There are other more important fish to fry besides a Walker Prothenium which IMHO is over the hill in terms of complexity and I am not in any way in favor of that tonearm. 

You and I have very similar tastes in HifI gear. Both our systems are based on ESLs and subwoofers. We both use Digital preamplifiers. My first suggestion is to get rid of the Velodyne subwoofers and get a pair of ML Balanced Force 212s. 

Next will be to trade the Trinnov in for a DEQX Pre 4 or 8. I almost bought the Amethyst until I got wind of the new DEQX units. They have far more flexibility than the Trinnov particularly in bass management. I will be getting mine in about a month. I was selected along with 119 other people to test the beta version of the software. We get a discount on the units. I think we are all getting Pre 8s which has a full 4 way crossover. I am not sure how ML set up the step up transformers of your speakers. The Sound Labs uses a bass and a treble transformer for each speaker. I am going to biamp the speakers using one amp to drive the treble transformer and the other to drive the bass. The crossover is at 5000 Hz. 

After this play around with cartridges and other sources. I use a Channel D Seta L Plus and use the computer to do the RIAA correction. I can raid my friend's record collections and make perfect replications in 24/192. You can use the vinyl recording software with any phono stage. I have started to stream with Qobuz and can buy files through them. It is a great way to keep up with new music. I still buy records. It is a habit I can not seem to shake. I also use a Sota Cosmos Eclipse Vacuum with a Schroder CB on it. The only other turntable I have my eye on is the Dohmann Helix 1. I would put a Schroder LT on it. I doubt this will ever happen as it is very hard to justify. I use three cartridges, the MC Diamond, the Atlas Lambda SL and the MSL Signature Platinum. At this moment I am not interested in other cartridges.

There is a new control unit for your Sota. Contact Donna and get in line.

I am getting a pair of Audiomica Allbit Consequence power cables for the SLs. skos brought a pair over telling me he heard them on another SL system and could not believe the difference. I thought he was joking! These cables have some type of filter. Darn if they did not increase low level detail beyond the realm of the psychological. For me to pony up thousands for power cables is a novel event.  Something is getting to the diaphragms that is polluting the speakers and I have my own power transformer on the street. I do not know if the same result would occur with your MLs but I would bet it will. You might message skos about them. 

I am going to use the MA 2s (Atma-Sphere) to drive the bass transformers as they are uniquely suited to that role. I will need a solid state amplifier with a very low output impedance to drive the treble transformers. Roger West suggested the Benchmark AHB2s but I was thinking of something more like the PAS XA 100.8s. Ralph would like to sell me his class D amps. This is going to be a tough decision. 

@tvrgeek ,

That is a statement only an inexperienced person can make. I do not mean that as a negative. People who experience a system with a processor like the Trinnov Amethyst in place are, to a person, blown away by the improvement in sound quality. Just subwoofer matching is enough to justify the unit. You can put these units in bypass and compare processed with unprocessed sound and no person could possibly prefer the unprocessed sound. Analog signals are fragile. Anything you do to them creates distortion. The same is not true of digital signals. You can not distort the meaning of a number. You can do anything you want to them without adding distortion. This opens up a world of capability not available to analog systems. If you are old enough to remember analog cell phones then you have experienced the comparison. Purely because of digital transmission modern cell phones are as good as they are today. The DAC only reads numbers. It totally ignores static and other distortions.  

The Benchmark is deadly accurate and the Hegel is not. This is purely a matter of preference. With a processor like the Trinnov you can make the Benchmark sound like the Hegel and take advantage of its superior signal to noise ratio. Hegel is made in China and I personally think at this point we need to avoid subsidizing that country. A processor like the Trinnov allows you to program your system to sound the way you want without adding additional artifacts while providing superior imaging and bass management. 

Humans are extremely change adverse and Audiophiles are definitely worse in this regard than other humans. Digital processors have been around for over 25 years and they still are not utilized at a level their value would suggest. Most of the high end audio companies lack the engineers capable of designing equipment of this nature. The farthest they go are DACs, a very basic item in the digital playbook. Some companies do streamers but not analog equipment. Of the hundreds of audio companies out there only a handful are capable of engineering processors like the Trinnov or DEQX. Anthem is the exception. They are the only company I can think of that does it all. 

The sound quality at many concerts is hideous. Much of the horror is do to the acoustics of the venue and not the equipment. The best sound quality is in smaller situations where the instruments are not sent through a PA. 

@neonknight 

Sorry, but that is not true. ESLs will move their diaphragms in an attempt to make bass and if you take a very near field measurement they would seem to be very accurate... until you move away from the speaker. Because they are dipoles there are interference effects that cause amplitude issues and wors, the longer excursions of the diaphragm Doppler distort everything else the speaker is doing. Not only this but the longer excursions severely limit headroom because the diaphragm has a very limited space to operate in, about +- 3 mm. 

I cross at 100 hz because this takes all the long excursion frequencies away from the ESL increasing headroom and lowering distortion. My subwoofers are passive and use Corian layered with MDF for their enclosures. They are stiffer and heavier than any commercial 12" subwoofer. With digital bass management you can not identify the subwoofers and these are not as good as I had hoped. The next model is almost finished and will be a big improvement. I have been experimenting with subwoofers under ESLs since 1979.

Given your assessment I have to assume that either your Velodynes resonate unacceptably or there is something wrong with the Trinnov's programming. To crossover at 100 Hz you have to use a very steep slope, at least 48 dB/oct and it should be Linkwitz-Riley. I do not remember if the Trinnov can do this. All I can say was when I reviewed the Amethyst several years back I was disappointed in the flexibility of the bass management. Having said this, the only commercial subwoofers that are reasonably accurate are the Magico Q series subs. They are very expensive and HUGE. The best subwoofers otherwise are the Martin Logan Balanced Force series subs. They resonate less because the two drivers opposed each other canceling Newtonian forces. The Magicos do this also and there are two Balanced Force KEF subwoofers that are smaller than the MLs. I know you would be happier with the MLs under your ESLs. I will review the Amethyst's bass management and get back as to what I think would be the best way to set it up. If it can not due 48 dB/oct then you have to cross lower. You do not want the subwoofer getting into your midrange. At 24 dB/oct 80 Hz is pushing it. My old TacT 2.2X could do 80 dB/oct in 1 Hz increments from 20 to 320 Hz. And, you could change it on the fly. There is one simple test. Turn the main amp off and listen only to the subwoofer which are going to sound really bizarre. This is normal. You should not hear any voice coming through. If you do you either have to increase the slope, lower the crossover point or both.

@neonknight 

Excellent. Remember, any change you make will require taking new room control measurements. You will need to do this for both crossover points then you store both of them in presets.(I think?) This is a PITA but it is the nature of the beast and will take up the better part of a Saturday morning. 

 Once you have it set up. Turn up the volume and see how loud you can go before clipping. Check to see if you can hear voice coming through. You should notice a big improvement. The subwoofers should be located between the ESLs. If the subs are still obvious than the issue is with the subwoofers. Make sure all the subs extra functions are bypassed. If you can't bypass the low pass filter in the subs turn them all the way up. By 1990 or so I had become so frustrated with commercial subwoofers I started making them myself and I am on the 4th version. The problem is that is is extremely hard to keep subwoofer enclosures from becoming musical instruments. Turn the volume up with a bass heavy piece and put you hand on a subwoofer enclosure. It will be vibrating more or less at different locations. It will also be shaking a little in reaction to the speaker cones movement. With the ideal enclosure you should feel absolutely nothing, no shaking and no resonance. It turns out this is a very tall order. Mass alone will not stop it although it helps. Using opposing drivers to cancel forces helps a lot but is not enough. The enclosure has to be so stiff that any resonance is at a frequency way above the subs passband so the driver can not excite it. This is a lot tougher than you would suspect. Magico does it by using a heavily braced Aluminum enclosure. Not very elegant, but it works. 

I also forgot to mention that the Trinnov is trying to make the bass (350 Hz down) reasonably flat. Is is driving the MLs harder at frequencies where the level is not sufficient making the excursion problem much worse. It is also robbing you of power and head room. If you want a real head turner get a separate measurement system. It will display the frequency response of the system before correction. Your bass will be all over the place +- 5 dB or more!

@johnlnyc 

OK, the question is why? Is the sound more to your liking or is the environment in the living room more to your liking, more comfortable. 

I spend most of my listening hours in the shop on a mid fi secondary system streaming from the main system over the local network. Sounds OK but not stellar.I spend more hours in the shop then my listening chair for obvious reasons. 

@lewm ,

It is not a theory and there is nothing to debate. It is much less of a problem for two and three way speaker systems because the bass driver's range is limited. It is a huge problem for our ESLs because they are full range. It is extremely noticeable with bass below 40 hz which few recordings have, but it still modulates the sound up to about 80 Hz. You hear it as a warble almost as if the speaker is shaking at high volumes. I think some do not notice it until it is gone. It bothered me right away as I tend to listen to bass heavy material at higher volumes. This resulted in my getting RH Labs subwoofers, a Dahlquist LP 1 crossover, and a pair of used Kenwood L07 M amplifiers. In typical audiophile fashion went things are getting too hot you turn up the temperature. This was back in 1979 and I am still trying to get it right although I think I am very close, 95% of the way there. 

@dogberry 

We had a lot of fun with the HQD system back in the day. Even though the Quads were crossed to subwoofers we blew them left and right giving demonstrations. I can still see Peter McGrath running back in the store room to come running back with a Quad on his shoulder, teeter tottering on a ladder replacing the upper unit. That people actually bought these things is beyond me. The Decca ribbon tweeter was even less reliable. I have no experience with modern quads because they are all point source speakers and I am a line source kind of guy. You might message skos and see what he thinks of the subwoofers and SLs. He has heard the system twice and is very opinionated. 

@lewm ,

Ok Lew, All I can tell you is what you get rid of when using subwoofers under ESLs does not sound like typical IM or harmonic distortion and it is most definitely modulated by the bass. If this is not Doppler distortion then perhaps you can come up with another name for it.

@neonknight 

Excellent, 48dB/Oct right? Linkwitz-Riley preferred. Pick a piece with an acoustic bass solo. Play at the right volume, as if the bass were right in front of you and compare. Then play a rock piece that does not have any synthesizer in it like, Little Feat The Last Record Album or a Steely Dan record like Gaucho and turn it up to 95 dB and compare. See how high you can go before distortion becomes obvious. Now try the same thing with a recording that has very low synthesizer or organ bass in it like Pucifier's V is for Vagina (sorry, I did not tittle the record) or Radiohead's In Rainbows. The acoustic bass is for accuracy and the rock pieces for power vs distortion. We wait anxiously for the results.

@lewm 

Lew, It is sort of like IMD but it is not. The change in pitch is dependent on the speed differential and direction of diaphragm motion which is frequency dependent. This motion is significant only at very low frequencies. It does not add side bands but causes a change in frequency (pitch) of the higher frequency.