Subwoofers - Final Thoughts with Martin Logan ESL 13A


I’ve narrowed this down to 3 choices (I think) and was looking to see if anyone has had some experience with pairing these subs with ML ESLs? I can’t try and return because they are mostly secondhand purchases, so hoping to get it right the first time!

Force Cancelling subs have been highly recommended, so:

KEF KC92 (or KF92 older model) 2, 3 or possible 4 of these:

https://assets.kef.com/product-support/kc92-subwoofer/KC92_info_sheet_EN_V4_20240124.pdf

Martin Logan BalancedForced 210 - Maybe the best as they match up nicely, but I could probably only do one of these as they are HUGE. I have only one spot I could put one as far as the manual's recommendation goes. Martin Logan says these will cover 3000 sq. ft. My room is only 500 sq. ft. Two maybe overkill, but some say, "2 subs or no subs" Maybe I could put another addition on the house :-( 

https://www.martinlogan.com/en/product/balancedforce-210 - click on Specs/Lit

Lastly, The Swarm Subwoofer System - not sure how well this would work with my ESLs.

https://www.audiokinesis.com/the-swarm-subwoofer-system-1.html

Any advice would greatly be appreciated (as usual).

Thanks, and all the best of the season to you all!

 

 

 

128x128navyachts

Definitely Swarm @audiokinesis. I like the BalancedForce products, but one alone won't help with nulls (to some extent, you can equalize out peaks). The KEFs are great, but I don't know how well they integrate with non-KEF speakers.

You have powered woofers in these speakers that you can tune to a perfect blend with the panels. You can turn up the bass and still retain woofer/panel integration. Adding extra subs, in my opinion, is asking for trouble. You will most likely not get the timing right and it will be a major pain to integrate.

@joeyfed55 I was trying to keep away from RELs but I'm glad you are happy! $7800 subs with $12000 speakers, big investment!

@hedwigstheme I was thinking the other way around 3 - 4 KEFs but not sure how the Swarm would integrate with the ESLs. 

@audphile1 Hey, nice to hear from ya, hope all is well! I have tried numerous ways to tweak the bass on the MLs. From the Perfect Bass Kit, to the dials on the back. I am not savvy enough (yet) to make adjusts with the ARC Genesis software, but I did send the files into a tech at Paradigm/Anthem AV support for them to tweak and I just can't seem to get it right. Yes, I have had subwoofers before and had trouble integrating them, but I thought I'd give it on last ditch attempt as I feel something is missing here.

I had ML Spires in the past, with only one 10" woofer and it had more bass than the 11As with two 10" woofers, didn't need subs.

Hey @navyachts all good here! Hope you’re doing well!

I never felt the need for subs with the ML Montis. I’m surprised to hear your setup is lacking in bass department.

It’s possible you’re sitting in a null. That’s the only thing I can think of.
I would recommend trying to move closer to and then further away from the speakers while playing a test track that is known for good bass. See if you hit a spot where the bass response becomes acceptable. One other thing to try is to move the speakers. Further or closer to the front wall. Make small adjustments 1” at a time. But try the listening position first.

@audphile1 appreciate the advice. I will try and play around a bit this weekend there just isn’t a lot of room to move stuff. It’s a very small space.

@sgordon1 - thanks, I was unaware, I will check it out.

As much as I love the ML Balance Force subs, I'd go with 2 of the Kef's rather than just 1 ML.  

a few bass tracks that you might enjoy and help you figure something out.

I just moved my Sumiko Talisman S Cartridge with it’d stiff Sapphire tube cantilever to my ’fixed’ long arm.

I’m gonna listen again to ascertain if it has a speck tighter bass than my AT33PTG/II playing Cecil, Mila, Niels/Sam

https://en.wikipedia.org/wiki/Alternate_Spaces

mila drumke, my funny valentine

https://www.youtube.com/watch?v=ukrNpHCDSjc

double bass, niels and sam

https://www.youtube.com/watch?v=-Jvz_hcTZ9k

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I am big on Imaging, and would try a stereo pair of subs, front firing, located next to the FL and FR, knowing that the fundamental notes begin mono, however the overtones become directional. I am not a fan of ports, if so, front firing only, and try stuffing them.

audiophile1 mentions the historic difficulty matching subs with electrostatics. I think I might try and find a high quality crossover dedicated to the job, one I could return for full refund. when you take the low bass job away from the panels, both location and seamless blend become even harder.

I’ve never heard a Swarm, but aren’t they for larger spaces? Use with speakers that have large woofers, that already give low bass/overtones directionality, the swarm for ’missing’ very low foundation?

I think of my 15" woofers as built-in stereo subs, I get the advantage of 6.83 cubic feet by using the same/larger cabinet as the horns.

@elliottbnewcombjr thank you for your advice and the bass tracks. I’ll hunt them down on Tidal later today!

I am not much of a techie, so could you explain to me more or attach a link regarding what to look for in the way of a "Dedicated Crossover"? How does it work?

You also mention a stereo pair of subs, do you have a recommendation? Would the KEF KC92s work for this? And would they be on the inside or the outside on the FL/FR speakers?

I am no sub expert, others here are far more experienced and knowledgeable about subs and everything else.

You need to hear options in your space, with enough trial time to experiment and not rush to judgement, AND, you need return/refund options, that ain’t easy.

I just impart what I have experienced for others to consider/try. I suspect too many have never heard great imaging which begins with ____ frequencies and presents the location of Jazz Bass players excellently. A member here made me aware, and I keep repeating, the overtones of mono fundamentals become directional.

Location, front firing, no ports is all primarily related to achieving stereo bass imaging.

I’m 76, I’ve heard Quads in demo and nice systems, all the NYC showrooms and annual hifi shows, Martin Logans, Carver’s attempts, some others, but have not heard subs and panels together in a home system. I just don’t know anyone who has that, or anyone with a swarm setup.

My understanding of Swarms is to extend BELOW a system that already has ’enough’ stereo bass imaging. Some might add a swarm to my speakers in this space, I am happy when there is 'enough' of a foundation, more can turn to mud easily.

I never bought any variation of electrostatics because of the ’less than full’ foundation that you are working on and what audiophile 1 referred to. Likewise, I never got hooked on ribbon tweeters, or super-tweeters as some people do. Inheriting 4 way speakers, horns with 15" woofers at age 30 has limited my experimentation.

1. separate low bass signals prior to the amp, thus you need a separate preamp, or an amp or integrated with pre-out

2. pre-out to a crossover to separate low bass for

a. a self-powered sub or

b. stereo pair of subs, or

c. swarm of subs. (I never heard a swarm)

3. low bass to sub(s) only

4. everything else above low bass back to the amp. Now neither the amp or the primary FL and FR need to try and make low bass, the most power hungry need and source of distortion.

IOW, stop asking a 6-1/2" driver to be a woofer, let it do a better/cleaner job with frequencies it can produce cleanly, starting with upper bass.

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the crossover can be in the sub, designed by the sub’s maker, using line in, it’s crossover, line out to your amp.

IF you use speaker wires in/out of a sub, the primary amp is still trying to make low bass, which makes it harder to use a lower powered amp (the easiest way to try tubes). It does take the low bass job away from your primary FL and FR, so that’s something, but line is best.

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I mentioned a dedicated crossover, a separate. It was more prevalent many years ago, self-powered subs with variable crossover frequencies and slopes have progressed as well as all forms of DSP which goes in/out of favoritism.

my friend, from my old dog era, might add a huge sub to his system (tweeter and pair of 6-1/2" drivers each side), and he will build his own crossover.

Perhaps members here can recommend a crossover separate that ’finally’ solved their quest.

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’Force Canceling’ has been around, and KEF and Martin Logan that you mentioned (their refined speakers, many models, affordable models lack low bass, they NEED to solve this) both have gone in that direction. Makes sense regarding the forces involved, and KEF has 4 preset location DSP settings. How to get some imaging out of them? I suggest you write them both, ask about adding subs without losing imaging, see what they have to say.

Is Force Cancelling More Important than Imaging? You would think 15" woofers, in cabinets with no bracing, would shake anything off their slanted tops, and yet, I let Donna put some things precious to her on top, they stay put.

I thought I might have to add some bracing when I had these made, but happily I haven’t. That ElectroVoice 15W Woofer’s monster magnet from 1958 weighs 37lbs. 3 Wheels (more weight per wheel, dual wheel caster's axels do not wobble) The 2x4 in the base lowers the front wheels 1-1/2", ’raises’; slants the face back, and aims the horn tweeter at seated ear height, while altering the angle of reflections from the floor and ceiling. Toe-In is easily changed for a single centered listener or two off-center listeners, also minimizing side wall reflections.

Toe-In Alternates, Stereo and Video

 

 

Did anyone notice Donna’s plants on a tray on top of my Reel to Reel? That tray moves to the top of the TT when I play tapes, the speakers move to wider positioning. I promised Donna the top of the equipment rack when we bought it, then I decided I needed to put some equipment on top, so I gave her two trays, and lots of trust.

Look at the top of the piano, and soon the little Christmas Tree: nothing touches anything else, felt feet, rubber buttons, 1/4" clearance, zero buzz kill.

 

2 Channel Imaging is Phantom, no driver is blocked, it’s simply the l/r balance that reaches your head

@elliottbnewcombjr What a wonderful story/advice, thank you (& Donna) for sharing, along with all the great photos (love those speaker cabinets). I will continue to persevere! 

That kef would be a good sub for your application. Pick up 2 of them and move them around behind your listening position.

The kefs and those bass modules built into the ML13A should make for good lil swarm, put you in a esctatic womb of bass from which everything else shines (when done right).

I used to have MLs once upon a time, during which the quality of subs were nowhere as close to what you can get these days.

 

"@elliottbnewcombjr    all the NYC showrooms and annual hifi shows, Martin Logans, Carver’s attempts, some others, but have not heard subs and panels together in a home system."

Could you describe, "Carver's attempts" at or with what? 

I just saw your Virtual System, those are awesome looking speakers in a beautiful space. I can imagine their sound, and suspect you are chasing something you don’t really need as audiophile1 implied, or said, not needed for him.

I mentioned my friend. He listens here, thinks he might need a sub. I agree he needed a sub in his prior space, however, we listen in his new smaller dedicated listening space, and I love his system, and always advise that he has enough bass, he could lose what is wonderful now.

His current space, I would first try a pair of reasonably sized stereo subs, pair of 8’s, 10’s? he is still thinking single monster driver. Years ago he built a table/sub with 18" woofer for the larger room, blew some amps, never got something he loved.

Send photo of your space to Martin Logan and KEF, that will help them help you.

m-db

Carver Amazing Loudspeakers 2

Adding more than a single woofer

Stereophile Review, I’m gonna read it now

A quick read revealed t was not a finished product when reviewed, an excerpt:

"Finally, I want to make it perfectly clear that, as of now, I do not recommend this speaker. If and when the design stabilizes, and I have a chance to evaluate a true production sample, then a final assessment can be rationally made. I consider it insane to spend any money on what has to be regarded, for now, as an evolving prototype."

I am extremely happy with my one ML BF 210 and my two CLXs.  Integration is important and ML gets you there easier with the custom crossovers you can download to the 210 and the PBK kit.  I previously had Kinergetics and Entecs.  The 210 is far superior.

To @elliottbnewcombjr  

Wow, not your typical Stereophile review - and by Dick Olsher no less, practically Bob Carver's Vacuum Tube Audio's personal press rep during the Cherry VTA 180 release. 

I still can't get my head around how someone could modify one of his solid state amplifiers within a two week stay in a hotel room with the parts on hand, and win the challenge! 

@navyachts   I have tried numerous ways to tweak the bass on the MLs. From the Perfect Bass Kit, to the dials on the back. I am not savvy enough (yet) to make adjusts with the ARC Genesis software, but I did send the files into a tech at Paradigm/Anthem AV support for them to tweak and I just can't seem to get it right. Yes, I have had subwoofers before and had trouble integrating them, but I thought I'd give it on last ditch attempt as I feel something is missing here.

I've yet to hear any method of signal processing or amount of amplifier watts that can ameliorate a subwoofers poor performance when located out of the rooms standing wave bass modes.

Locate and position the subwoofer within the modes only then should processor and or EQ adjustments be made. The speaker matching comes as a byproduct of the subwoofers available adjustment parameters. (Does not apply to -6dB sub-bass speakers.)

https://www.audioholics.com/home-theater-connection/crawling-for-bass-subwoofer-placement

From your list +1 the AK Swarm. When I setup a distributed bass array (Swarm) in my home using dissimilar subwoofers the need for bass mode positioning was not needed. Simply put, the boundary located array takes the room out of the equation  providing an almost uniquely unparalleled low frequency timing presentation.

@audphile1 so I toed in the speakers a bit more moved the chair closer to the speakers. They are now 6’ apart, 33" off the back wall and I’m sitting about 12’ away and yes, I’m hear a tad more bass as I move closer in.

It really seems to be about the music here too. I played Deep Bas by Niels & Sam recommended by @elliottbnewcombjr and I heard good clarity and detail but not Deep Bass as the title states. Then I listen to The Hidden Camera by Photek and An Evening In Dallas by Joe Sample and you could feel the bass pound the floor.

I would like to be able to tweak the bass myself with the Genesis ARC program, but I don’t know anything about frequency response graphs and all that stuff. I have looked around the web and can’t seem to find much on this?

@m-db thanks for your input. I wouldn’t mind trying out the Swarm set-up, but it used to be $2,500 now I see it’s $4,400 and I would want white, so it’s more for a custom color. I could do a couple of used KEFs for around $1,600.

Thanks for the Audioholics article. I think I just need to "Crawl" outta this rabbit hole, maybe trade it all in for a Sonos system and call it a day!

Have you ever experimented with the rake angle of your speakers?  Lowe’s sells plastic shims that make this very easy; try a downward tilt.  You may also want to shorten the distance from your listening position to the speakers.

My CLXs are bolt upright (to within 0.1 degree using a digital level) and are with exactly zero toe-in and exactly the same distance from the front wall (5-6 feet) and the side walls, using a laser "tape" measure.  Speakers and I are set-up in an approximate equilateral triangle.  I can measure for you if you think it matters. 

FWIW-perhaps the best sound I had from my CLSs was firing down the long axis of my then living room and having the speakers in the middle of the that vector, at the suggestion of Michael Green.  It only works in some living situation and with a very easy going partner, lol

My CLXs are bolt upright (to within 0.1 degree using a digital level) and are with exactly zero toe-in and exactly the same distance from the front wall (5-6 feet) and the side walls, using a laser "tape" measure. Speakers and I are set-up in an approximate equilateral triangle.

No need to measure thanks. I can do all of that except get the speakers 5 - 6 feet out into the room. I would have no room left! But just for fun, when the wife is at work tomorrow, I may just give it a shot!

ML recommends the rear of the box to be 0nly 10" off the back wall for the 11As (I’m a tad more than that) and 24" off the side walls. I’m 24" off the left side and open to a kitchen on the right. I usually set the toe in with ML’s flashlight method to begin then move them around accordingly. My wife likes them toed in a bit more. Again, I will play around with this tomorrow. Thanks for all your suggestions!

@elliottbnewcombjr interesting, thanks. Tough to find any reviews on them, been around since at least 2012.

My first recommendation would be 2 subs at a minimum.  I've had the Swarm and it would likely work well with your room.  Acoustic studies (see @rauliruegas comment on my post-Subwoofers are a superlative room treatment) demonstrates that 4 subs are the optimum number.  The Swarm enclosures are small enough that they will likely fit well in your space.  These little guys can put out bass, but by virtue of the noise cancelling properties of 4 staggered subs, will make your overall sound much better. Much much better. Duke Lejuene, who designed and manufactures the Swarm, is also extremely knowledgable and will help you with the set up and adjustments as necessary, as he did for me. He will also help you decide if his system will work with yours.   I did switch them out in favor of 4 B&W DB1B's, though.  My Magico S7 speakers have 3 10" woofers apiece and the the Swarm has 4 10" drivers-not enough for my system, but likely more than enough for yours. There is contact info for Duke on the Audiokinesis web page.  I'm excited for you-a pair or 4 subs will do a lot for your system once set up properly!

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@ozzy OK, sorry for my ignorance. Once I figure out what a test signal is and download it, what do I do with it? Do I need a microphone, computer software, etc?

Then, how do you relate this signal from the mains to that of the subwoofer?

Is there a link somewhere on how to do what you are suggesting? Thank you

 

 

 

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FYI, my subs are set at 70hz.  Perhaps start at one end and move to the other to find what suits your ears best.

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@audphile1 OK, I move my listening chair closer in and moved the speakers further out from the wall, then toed them in a bit more than the ML recommends. I also ran the Genisis Arc program (in auto) and as long as I play well recorded, bass heavy music, (like one of @jasonbourne52 favorites, Slow Jam by Euge Groove), it sounds pretty good and goes pretty deep. One thing I did notice, when I turn the .arc3 file off (so less bass) I hear more detail in the mids and the highs than when the heavier bass file is turned on.

I’d still like to try a sub. I have my Coda pre-amp up for sale so if & when it sells, I may use the funds to pick up a sub (or two).

@docknow I see a couple of 210s came up here on Audiogon, I’m trying to scrape of the funds for one or two. Christmas time is a tuff time to do so.

Thanks to all for your help & advice!

Dear @navyachts :Main subjectUissue why add subwoofers in an stereo room system is not really " add more/deeper bass ".

All speakers including yours and the lovely S7 owned by @orthomead or the great Rockport owned by  @workeuptobose normally are designed using a internal passive CROSSOVER from a 2-way speakers to 4-way and up speakers.

Where is the " problem " there about that crossover frequencies for the different speaker drivers frequency range?:

In your case your ML crossovetr frequency to the woofer is 300hz and the speaker can goes down to around 22hz and; what that means?

it means that at the same time that that woofer drive must handle the 22hz, 30hz or 4o hz it must has too reproduce frequencies that can go over 300hz and the big woofer excursion need it to develop 22hz makes that the frequencies over 100hz develops a high INTERMODULATION DISTORTIONS ( no matters what. ) and this IMD is a huge signal reproduced degradation and it’s precisely here where 2 self powered subwoofers ( NOT ONE. ) helps a lot because when the woofer of the ML main speaker handled frequencies above 80hz-90hz and is liberated from the bass below 80hz-90hz that IMD goes automaticallt down and not only the bass range will shines but the midrange and hi frequency range too because we have to remember that MUSIC harmonics are developed by all the speaker drivers and if the IMD already gone down in the bass the bass range harmonics will be CLEAN with lower distortions and will permits that the mid range and hi frequency ranges stay in the same way: lower in distortions and clean/purity with lower signal degradation.

The " side " benefits of adding those subwoofers are not only what I posted but now the low bass range it will be reproduced by a dedicated driver designed in specific to handled with absolut applomb the frequency range and go deeper too in that range and with a dedicated amplifier that was designed to run on that bass specific range too along that your main amplifier will be a lot les distressed when is not playing/looking the low bass frequency range.

All those means that we need a high-pass filter to separates the frequency that goes through the subwoofers and the frequency that goes through the main speakers.

The solution that way is: win to win.

You said you need to improve the quality performance ( including bass. ) to one seat position and this means you need ONLY 2 self powered subwoofers crossed at 80hz, you don’t need the swarm solution that is for several seat positions.

Other issue with subwoofers is that exist quality levels between different manufacturers designs and due that the foundation and where the MUSIC belongs is the bass range you need subwoofers with very low developed distortion levels .

 

@ozzy posted to you: " play the main speakers full range " and with all respect this is a mistake that almost all audiophiles made/make by recomendation as REL manufacturer. Here you can read by an expert in the subject why that assuption is wrong even if we own the Magico S7 ( I can’t find any where the crossover frequencies of the S7 but obviously use a crossover and develops too IMD as the Rockport too that additional is a ported design and this means that here we have 3 bass sources: the front woofers, the back port and the subwoofers ( no one can control timing to run in our ears bass range because those 3 bass range coming with different delay) ):

 

"

The ONLY correct way to add a sub to system is to define everything ABOVE the sub’s [frequency] range as an entity; clearly define the impulse, phase, and lastly frequency response of this entity; and then make a new "2-way" system where the sub is one way and everything above it is the ’other’ way. The parts must be combined correctly so that there are no cancellations and no smearing of time-related musical events.

This CANNOT be easily measured in the frequency domain, because you could have (as an example) an 80 Hz signal coming from both the mains and the sub, and if the sub is 12.5 msec late the two sources will "seem" to be in phase but the sub really will be 360 degrees, or one full wavelength late. It is the impulse smearing that this affects, but people don’t measure that because there is no simple "hand held" phase or impulse meter as there is an SPL meter.

The REASON this meter does not and essentially cannot exist is that in order to measure impulse response or phase response you need a starting REFERENCE point, (in time) and in a speaker system, since the signal has to travel through circuitry, amplifiers, passive crossovers inside the speaker box and then hit the driver; therefore the first reference point MUST be acoustic.

There ARE computer based impulse response systems such as the TEF, ( very quick technical blurb HERE; full story HERE ) but they are involved, require real instrumentation, are expensive, have a seriously steep learning curve, and they are absolutely not the kind of thing most ’consumers’ -- or audiophles, can be bothered with or have patience for.

So the overall view of adding a sub is this: In essence you are designing and assembling a new speaker system which is "2-way": the sub is one way and everything "else" above it in frequency is the 2nd way.

Simply connecting a sub to existing mains speaker (or amp) terminals ( or self powered subs. ) is the WORST POSSIBLE WAY to do this. EVERYTHING scientific and acoustic about this method is wrong, from the additive delay issues to the back EMF of the mains affecting the LF signal. However there are plenty of people who simply do not understand correctly integrated bass, and they will be reasonably happy simply sticking another box on to their system without regard to timing, phase and frequency issues, and they will think it sounds "ok" or "good" and for those people it doesn’t really matter.

Indeed the only thing that does matter is an individual’s happiness with their system, whether I or anyone else thinks it’s right or wrong.

But I want you to know and understand the truth, so to get purely technical...."

 

Btw, the subwoofer with lower THD ( Total Harmonic Distortion ) level and reasonable price are these by Veñodyne esclusively design due that too comes with high pass filter:

 

Digital Drive Plus - Velodyne Acoustics

 

Regards and enjoy the MUSIC NOT DISTORTIONS,

R.

@rauliruegas Thank you so much for your lengthy, informative, kind reply, so much information, I will have to read this 3 of 4 times, for sure.

But in the end, this pretty well sums it up:

Regards and enjoy the MUSIC NOT DISTORTIONS

Thank you again and all the best!

 

I noticed a picture of the carver amazing speakers.i do like the ribbons and the sound of the woofers.to my knowledge the cross around 180hz.enjoy the music and the experiments it stimulates the mind.keep active.

@navyachts balanced sound is key. Too much bass and it overshadows the mids and highs - you lose clarity and details. Not enough bass and your system will most likely sound bright. Use the flashlight trick for the toe in with MLs. I would still recommend to pursue resolution to your bass concerns with speaker placement. 
With MLs pulling them about 4 feet (panel to front wall behind speakers) worked for me. About 96-98” apart center to center. If it all fails try a sub. 

Also…check the filter settings on the DAC. I find the Minimum 0, Clock Wide to produce a bit warmer and fuller sound than the Linear 0. The difference is subtle but audible.