Phono Stage upgrade to complement Dohmann Helix One Mk 2

@mijostyn 

I spoke with Duke LeJeune at Audiokinesis, and he agreed with you that the "Swarm" would not suffice in my room, due to its size.  He mentioned that he could make some custom subwoofers with either 12" drivers or possibly with s 10" drivers per box.  His set up would have the potential to be sealed, vented, or double vented.  He also mentioned that his subwoofers are passive, but he recommends a amplifier that can be set to a 4th or 5th order LPF.  Presently, I'm going to investigate and pursue this option for the next few weeks. 

Ask Duke if he can do two 12” drivers per enclosure in a balanced force arrangement. Sealed enclosures only please. 

If you really wanna go crazy, and if you have a big room, ask Sound Labs about their B1 ESL subwoofer.

Dear @drbond : You are a gentleman that go where the " wind " " hold " you and change your targets as you can change your shirt. Nothing wrong with that because is what you show in the subwoofer issue.

Your main word about subwoofers was: trial and from there several changes to even disregard the Magico sub’s because its amps are class D and perhaps ( but I doubt because you have the kind of money need it for the Magico’s ) its price.

 

Now you are looking for a custom made sub’s and all your mind changes only for what you read through internet with out listen to any sub in your system or in a more or less similar room/system. Again nothing wrong with that.

 

Well taking in count your kind of mind about here are two truly good options for what you are looking for that I don’t tall before because I had in mind that " trial " you ask for. Anyway here it’s:

 

Krell Master Reference Subwoofer Subwoofers user reviews : 4.5 out of 5 - 4 reviews - audioreview.com

and here you can buy two of them:

 

Krell Master Reference Subwoofer (highperformancestereo.com)

 

and for you like to read:

MRS_man (krellhifi.com)

 

krell master reference subwoofer pictures - Búsqueda (bing.com)

 

If you dislike Krell then here other alternative:

 

Wilson Audio - Thor’s Hammer

 

If you want the crossover too then triel this one:

 

FM 330 Linear-Phase electronic crossovers - FM ACOUSTICS LTD.

 

FM 1811 highest accuracy in music reproduction. - FM ACOUSTICS LTD.

 

You can surround your choosed subs with FM Acoustics. Even custom made:

 

Professional Products - FM ACOUSTICS LTD.

 

R.

 

 

Fathom is another company that make expensive high end (or high end because expensive) subwoofers complete with x-over and amplifier. I's sure without looking that Wilson Audio do too.

Now and if you are really seriously about the full integration bass managdement then maybe what you could need is something " radical " as could be to put on sale your SL speakers in change for something like this:

 

MMSeven (evolutionacoustics.com)  and its specs:

specifications-for-group-brochure-4.pdf (evolutionacoustics.com)

 

or like this:

 

Mono & Stereo © 2023: Gryphon Audio Pendragon Four Chassis Loudspeaker system review (monoandstereo.com)

Gryphon latest model is : Kodo in 4 towers.

 

Both manufacturers choosed active bass management with no compromise at all.

 

Btw, M.Lavigne owns the MM-7.

 

R.

@rauliruegas 

Thanks for your suggestions.  I'm going to see what Duke at Audiokinesis comes up with.  He sounds like he really knows what he's talking about, and is interested in helping me get the best out of my Sound Lab ESL's.  He's also a Sound Lab dealer, so he's very familiar with what the speakers could use for augmentation.  It sounds like I'm probably headed down the custom-built subwoofer route.  Presently, we're looking for an amplifier / HPF combination that can work down to 16 Hz, which is low C.  (Yes, that is a key note in Bach's Passacaglia and fugue in c minor.)  

Presently, most every other component in my system is non-negotiable.  

As I mentioned about a week ago, you’re in good hands with Duke. You’ll be going to a lot of trouble to hear one lowest note in one piece of music, which I presume is emanating from a mighty organ pipe.

@lewm 

The standard amplifier that he pairs with his subwoofers goes down to 18 Hz.  We'll see what he's able to find.  (By the way, if you haven't heard that organ piece, you should give it a listen.  My friends who don't even like classical music are amazed by that composition.)

@drbond , just another dance tune. I have three versions of it, two by Biggs and another by Herrick which I like the best. That note makes my vision blur. 

For subwoofers you want an amp that goes down to 0 Hz, DC or darn close. The Parasound JC1+ is perfect. It will produce it's rated power down to 2 Hz. 180 amps!

@lewm , it is not just notes. Large venues breath. Lots of noises are generated by instruments that are not notes. It is that information under 30 Hz that gives you the sensation of a live performance and elevates a system from just another stereo. Low C causes my entire house to rattle, my vision blurs and you feel it but you do not hear it. The hand of god. IMHO ESLs make lousy subwoofers. 

@rauliruegas , shoot Raul, I wouldn't put those in my tree house. Huge resonating enclosures, crossovers all over the place, el cheapo air motion transformers. Yuk. A pair of LS3 5As on stands with subwoofers would sound better than those things. Remember the Nearfield PipeDreams. You could not get those speakers to image if your life depended on it. 

Dear @mijostyn  : In this regards and with all respect I really don't care of your opinion because I'm not talking of your " holly grail ". Live with and let live.

 

R.

Dear @drbond  :  I can see that you are not taking bass quality level sound that's the first and critical target when we are speaking of true high end.

Integration of subs is not only to lower IMD but the bass THD response level because its harmonics are the ones that puts " dirty " and makes that the mid/high frequencies range get dirty too and this fact has a name: degradation sound reproduction.

Talking of quality lvel performance I can't know how your sub's seller can even the quality of the Krell/Gryphon amps and how the THD of each sub stays inside 1% at full power down to 20hz.

In the other side I xcould think that your seller/manufacturer will gives you a configuration of 4 sub's that helps to even the room bass response especially to use in HT systems where you need several seat positions with that evenly bass.

In the other side if your main system is for listen stereo MUSIC then normally you have only one seat position where the mid/high frequency ranges performs at its best and the Harman Int. research shows that for one seat position 2 subs performs really good.

I can't link here the 30 pages of that modeling deep research and here only some highligths:

 

 

""" With 5000 subwoofers, modal variation is virtually eliminated. The frequency response at all 16 seats is nearly identical. ASIDE This curve is a combination of 2 influences: The power response of the modeled subwoofers (the simulations included measured Entre 12” subwoofer power responses). The effect of the real-world subwoofer response can be seen above 8 Hz. ""

 

""" The next four figures show results of optimization of 1 to 4 subwoofers in the test room. Locations of subwoofers were constrained to be along the walls, at intervals of 2 feet. Optimization is based on Std only, i.e. the configuration with the lowest std is considered optimum.  ...Obviously, wall midpoint locations result in optimum room response, based on the std anyway. Not surprisingly, symmetrical configurations seem to work better than non�symmetrical ones. Four subwoofers results in the most symmetrical configuration and the best results, but with significantly less (normalized) low frequency output than two subs """

 

"" Two and four subwoofers at the wall midpoints are still the best configurations overall. Four subwoofers in the corners does not seem as advantageous as when the grid was centered. There is still little or no advantage to using a large number of subwoofers. LF factor still goes down for higher numbers of subwoofers.  ""

 

""" One subwoofer at each wall midpoint is the best in terms of Std, Max-ave and Max-min but does not support low frequencies particularly well. Two subwoofers, at opposing wall midpoints, performs very nearly as well as four at the midpoints and gives a much better LF factor. One subwoofer in each corner also has good low frequency support, but does not perform quite as well as one subwoofer at each wall midpoint, in terms of Std, Max-ave and Max-min. If cost and aesthetics are considered, subwoofers at 2 wall midpoints is preferred. ""

 

 

The fact that 4 sub's could even the bass response it does not really matters if you have one seat position where 2 sub's can doit if the sub's have the whole quality levels.

I don't know if you noted on different links in my last post that all those subwoofer ( as the Magico. ) use metal frame for its box. The 1% THD does not comes  just at random no inclusive Gryphon said something That I posted here: " his dedicated class AB amps were designed to fulfill the woofers needs and re-read what Dan ?dagostino said in his Krell sub manual and what Wilson posted too and Evolution Acoustics where its common denominator/main target is QUALITY and a side advantage of that quality is to have deeeper bass response.

 

Anyway is up to you and of course is your money and only you can decide how spend it or invest it.

 

R.

@rauliruegas , now you've hurt my feelings. No desert for you tonight:-) There are a few strange comments your references make. Nodal behavior is a function of the room. Certainly it can be modified by placement. This fellow asserts that more drivers result in a lower LF factor (Low Frequency). I can only guess what he means by this.n Maybe @lewm knows.  Larger and more numerous drivers decrease excursion distances resulting in less distortion. He want to position subs at the midpoints of walls. If you are using your subwoofer array to lower distortion in the main speakers the higher crossover points have more benefit particularly with ESLs. Crossing at 100 Hz requires a stereo subwoofer array to avoid locating the subwoofers. There are also differences in requirements for the type of main speaker, line or point source. If you put a point source subwoofer array under a line source the subwoofers will become lost not having the same power projection. Its easy to cut volume but harder to increase it. Given large high quality drivers the quality of the subwoofer is mainly determined by the enclosure, large enclosures being significantly more problematic. Controlling resonance in a large panel is much harder than controlling resonance in a small panel. Given proper digital signal processing it is very possible to make a 1.5 cubic inch enclosure with two 12" drivers. Given enough power you can make them do anything you want and you do not need ports to get lower. We have the automotive crew to thank for modern driver designs, light cones, large voice coils and magnets, kapton formers, adequately vented, with shorting rings to lower distortion and finally long throw suspensions and kevlar spiders. You can get the finest subwoofer drivers for $250.00.

The wife wants me to make dinner. 

We have the "automotive crew" to thank for ear-damaging incoherent bass thumps, not music.

drbond, I love classical music and especially I love Bach, because he would have been a great jazz composer.  I just have the Clint Eastwood approach to deepest bass: "A man's got to know his limitations."  Which in this case means I would not make the sacrifices or put up the cash needed to generate 16Hz in my listening room.  There is probably only one actual organ (let alone an audio system) in the DC area that can reproduce that note, at the National Cathedral, about 4-5 miles from our house. But I admire your determination.

Just find a used Herron VTPH-2A, get a spare set of tubes and stop worrying about a future upgrade.  There isn't anything better.  

Drbond has a new phono stage, and it’s not a Herron.

Dear @lewm  : "  to generate 16Hz in my listening room... " well a sub can generates the 16z tone but the real problem is that the 16hz wave is big and can't be " developed " by the room/system.

Big organs normally are instaled in cathedrals/churchs.

The original 1812 Telarc LP ( that many of us own. ) has recorded deep bass notes ( 6hz-8hz ) coming from the different cannon shots and the only I can listen and feel for all and around my body are its harmonics.

The transient response in a room/system that cause the " bass impact " are all harmonics developed by those really deep bass notes.

 

Even that and at high SPL the experiences with are overwhelming.

 

In a real room/system almost only the gentlemans that own the MM7 speakers could have a more " complete " experience about that Telarc due that the speaker active subwoofer goes down 7hz but I don't know if M.Lavigne already tested that 1812 LP in his MM7.

R.

Agree, Raul.  And no one brings up that point, that when the wave length of the tone exceeds the size of the listening space, there is a problem.

@lewm 

Yes, that makes sense.  I'll see how things work out.  Presently, with just the SL speakers, and playing the 16 Hz note on vinyl, the walls shake;  oddly, playing the same piece on digital doesn't cause much to shake, but just the normal vibration of the listening chair, etc. 

@lewm ​​@rauliruegas @drbond , that is lay instinct. I can make a 7 hz sound in a telephone booth. It will not reverberate but it is quite measurable. Same goes for most rooms. It is true that you only hear the harmonics but you feel the note and you can measure it with a calibrated microphone which I have. Very few subwoofer systems are capable of projecting anything below 25 Hz. It takes a lot of surface area to create the wavefront properly. I currently use four 12" drivers in a 16 foot wide room. The 3 dB down point is 18 Hz and it falls off rapidly under that. The system I am working on has eight 12" drivers. I would use 15s but they would make the enclosures too large for my situation. Eight 12's are the most I can cram into the room. If that does not do it then I give up. Playing Vinyl I use a very steep subsonic filter anyway, 80 dB/octave.

Can you feel the Schumann Resonant frequency?

@lewm , it depends on what state I am in. In New York and Vermont I can, but in Rockingham County, New Hampshire, not at all. 

SLs have so much surface area impedance matched to air that they can surprisingly produce very low notes even though they are dipoles. I don't think they can do it accurately, the wild swings in output below 100 Hz are measurably worse than regular dynamic speakers in my room anyway. As lewm knows I cross out of them to the subwoofers at 100 Hz. Relieving them of low bass helps them to perform better everywhere else. It sounds like lewm is thinking of the possibilities. I was always a volume freak. If it did not go loud I was not interested. I got into subwoofers back in 1979 because I had fallen in love with loudspeakers that did not go loud enough, not even close. Subwoofers solved that problem but added others which I struggled with for years not willing to give up on ESLs running cleanly at volume playing anything from Chopin to Nirvana and everything in between except Lawrence Welk. ESL owners who lead more sedate lives might fare better without subwoofers especially if they are unwilling to go down the digital signal processing path. Bad subwoofers are way worse than no subwoofers. Distortion is noticeable lower in full range ESLs if you remove the bass from them. The louder you listen the more noticeable this becomes.

I have to go clean my Schumann Resonators now.