Subwoofers - Final Thoughts with Martin Logan ESL 13A

rauliruegas.

You are correct, Velodyne are the best subwoofers! 

m-db,

"Could you describe where in your room you positioned the dual JL Audio F112 v2’s the SVS Ultra’s and the Martin Logan Depth i and HSU subwoofers?"

No, I’m not going to continue to go back and forth with you. 

Dear @ricred1  " " I don't want to be rude, but I simply own REL subwoofers. I don't work for them, I'm not a REL fanboy(I don't like their subs with a passive radiator), and I don't get into measurements.  ""

NO, you are not, you don't have to worry about. This is a dialogue.

 

" I don't get into measurements. " Well, I posted in this thread that always it's essential that every audiophile you included need to mantain a good equilibrium between our subjectivity and the objectivity ( specs, measurements, technical issues and the like ) and I can see that you have not that kind of equilibrium and go " walking " through 100% subjectivity as: " I like it " or that's the way I like it. Nothing wrong with that becaus that's you and that you use your room/system as HTS too and that's what REL site says and what REL makes always but REL is not truly competitive against say this today Velodyne that by specs and measurements puts on shame any REL subwoofer:

 

Digital Drive Plus - Velodyne Acoustics

 

There is no contest down there and only the 60K+ per unit  Magico subs are near the Velodyne with a 0.4% THD or the fantastic subwoofer coming by Evolution Acoustics that goes -3db at 7hz-100hz and -6d at 3hz to 100hz.

 

That Evolution subs unit comes with 4 treated PAPER  15" woofers and each sub weogths around 300kg and very expensive as are the Wilson subwoofers too. ( why treated paper instead other today materials?, please read my next post).

Those are two examples why objectivity is so important even that you don't care about and that is up to you and I respect that.

 

R.

@m-db check out his virtual system here on Audiogon

ricred1,

My apologies that my lack of specificity led you to feel the need to justify your personal taste. You have been very clear about your current level of satisfaction with your systems speakers. 

Could you describe where in your room you positioned the dual JL Audio F112 v2's the SVS Ultra's and the Martin Logan Depth i and HSU subwoofers?

Example: Between the speakers, corners of the front wall, same plane next to the speakers etc? 

 

rauliruegas,

"Dear @ricred1 : In this link and in any REL information you can’t find out which is the 31/32 THD that is essentially a meaning of the true quality subwoofer performance levels. If you have information about then please share with us:"

Sorry and I don't want to be rude, but I simply own REL subwoofers. I don't work for them, I'm not a REL fanboy(I don't like their subs with a passive radiator), and I don't get into measurements. In my system/room, I prefer the NO. 32s because adding them has improved everything across the audio spectrum. The 32s disappear and you can't tell they are on, until you turn them off. I'm not telling anyone to buy them or saying they are the best for everyone.

navyachts,

Thanks for your kind words.

@ricred1 - by the way, that’s a beautiful system you have there!

m-db,

My subwoofers were set-up by my dealer using REW, listening, and the No. 32 parametric equalizer. They are on the outside of my speakers.

"you are the only staunch sub user I can recall who prefers a -6dB sub-bass speaker to the -3dB subwoofers you’ve owned." Subwoofers aren't just about bass and that's why I prefer the No. 32s. It’s what I prefer based on actually owning several subwoofers. As I always say, no absolutes in audio, only preferences. I don’t understand why people care what people spend their money on. It’s simple, if you don’t like REL subwoofers, don’t purchase them.

The one thing I like about the Rel is that you can potentially hook it up and use it as support when watching movies. Is this an option with the SVS 16? Does this mean finding s radio shack to rig some connection?

I should add that I just have a basic tube amp, not a receiver with all sorts of "outs" so I essentially be hooking the sub up to a soundbar for tv use.

@rauliruegas I get it. But…I’m enjoying the music with my system and I do not hear IMD. Neither do I need to obsess over it because…
According to Wilson Audio…

The tweeter is isolated internally from the midrange and woofer drivers with the latter two transducers sharing the same internal volume. Wilson Audio notes that in this configuration any potential for intermodulation distortion is minimized by prudent driver selection and precise porting of the enclosure. 

This sounds like truth as I cannot detect any distortion. The drivers cross over seamlessly. 
 

I’m very thorough when it comes to my system but I think we’re attempting to shoot down a fly with a bazooka here…

By the way I looked at your system page and I’m very impressed! Gorgeous system and some collection of cartridges you got there…enjoy!

"@ricred1  I prefer the 32s to every previously owned subwoofer...dual JL Audio F110, dual JL Audio F112 v2, HSU, Martin Logan Depth i, and SVS 16 Ultras."

ricred1, you are the only staunch sub user I can recall who prefers a -6dB sub-bass speaker to the -3dB subwoofers you've owned. 

Could you describe where you positioned those subwoofers in your room?

Dear @ricred1 : In this link and in any REL information you can’t find out which is the 31/32 THD that is essentially a meaning of the true quality subwoofer performance levels. If you have information about then please share with us:

 

No.32-One-Sheet-August-17-Vfinal.pdf

 

In the REL manual we can read the main target of REL subwoofers:

" A REL is designed to augment the performance of " full range " speaker systems in order to provide linear response below 15 hz. "

There is no information which kind of " linear " response below 15 hz ¡ ¡ ¡ ? ? ? when it says in the specs that is down 15 hz with a -6db deviation. That has no sense.

That " augment " means that the " full range " speakers " continue to play " full range " with high MD and now you have two bass sources playing together from 90hz and belows it ¡ ¡ ¡ ¡ ¡ Terrible for say the least and then you pay over 10K for one Rel unit.

 

I respect all your opinions but as mine is only an opinion that IMHO is full of misunderstood in this particular subject and REL specifically.

 

Btw @tablejockey " swarm ( 4 or more subs in the room ) function as the Harman link posted in this thread shows only to even the low bass response all over the room ( if you have only one seat position and cares only about your seat position you don’t need more than 2 subs as confirmed the Harman link. ) and it does not look for bass quality response and/or the quality response of the main speakers and its woofers developed IMD: swarm just does not helps about. Get it? and yes I can be wrong but this is my whole take rigth now .

 

Thismis the link:

Microsoft Word - whitepaper10.doc

 

R.

 

Dear  @audphile1   : Overall agree with you however there is one issue where almost does not matters the room/system you own and this is the IMD developed by speaker woofers if the speaker passive internal crossover is high as in the ML or your Sabrina. Wilson is no exception to that IMD.

 

Now:  " Turn up the bass level knob in the back of the ML woofer cabinets. "

 

If @navyachts  makes that then the IMD will goes higher and higher, IMHO it's not the " solution ". There is no way to lower that ML woofers IMD.

 

R.

@navyachts You got it! Keep us posted please 

@ricred1 Enjoy!

@tablejockey

I can just dream for know about some giant Soundlabs and a swarm of REL No 32’s.

LOL, me too! Thank you and @audphile1 for the commonsense advice. I will follow through with that next listening (playtime) session!

I have been following this thread to read how different opinions can be.

Stat users are either in the ML camp or "other"- Soundlab, vintage Quad or whatever. 

Your 13A's to my ears can sound very impressive with basic placement according to room allowance.- living space or dedicated.

If it's NOT dedicated, then you accept what you have and enjoy.

That's including bass response.  As audphile1 mentioned- those things need to be pushed out into the room. If space allowed doing 1/3 of room or Cardas might be ear pleasing.

Sub or subs will always  make the experience more enjoyable.

It doesn't need to be so technical as implied here.

Just my thoughts. I use ML's previous generation, bottom of the "premier" line Theos-passive woofers. They are supported by 2 ancient REL's but alone deliver listeanable performance thanks to placement and SOURCES.

I can just dream for know about  some giant Soundlabs and a swarm of REL No 32's.

It's what I prefer, but it certainly doesn't mean they're for everyone. In my opinion it has nothing to do with price, but what I value. Everything impacts a system and in my particular case, purchasing REL No. 32 subwoofers and a Antipodes Oladra music server has been two of the best decisions I've made for my system. I submit SVS and RELs impact systems differently. 

 

@ricred1 at almost $13K a pop you better prefer them to the measly priced SVS 16 Ultras :-)

@rauliruegas thank you!

Dear @navyachts  :  The SVS App will be tell you all about the placement of 2 subs and everything around:

 

SVS App Specs:

• The most powerful and flexible Bluetooth controlled subwoofer DSP app, works with both iOS and Android operating systems.
• Easiest and most convenient way to adjust crossover frequencies, parametric EQ, polarity, room gain and all other bass management functions.
• Three convenient custom presets allow for perfect tuning in any room or system, from your favorite seat.

• Single tap adjustment for controlling variable port tuning with standard, extended and sealed modes.
• Unique bidirectional feedback shows adjustments in real time on both app and subwoofer interface.
• Easy-to-follow tutorial provides clear guidance for all functions

You need a High-Pass filter for your main ML speakers, this is critical.

 

Yes the 4000 can function for your room/system

 

R.

 

R.

navyachts,

"@ricred1 sorry, I missed the point, are you in agreement with @rauliruegas ?" I submit audio is personal and there are no absolutes. I personally don't like REL subwoofers that use a "passive radiator", because my listening room is upstairs and I could hear the radiator. My point was REL does have "true" sealed subwoofers(No.31 and 32). In my system, I prefer sealed REL subwoofers and I use dual REL No. 32 subwoofers. In my room/system, it isn't just about bass, but how adding the No. 32s have improved everything across the audio spectrum and the soundstage. I prefer the 32s to every previously owned subwoofer...dual JL Audio F110, dual JL Audio F112 v2, HSU, Martin Logan Depth i, and SVS 16 Ultras. I prefer my system with subwoofers, some don't.

I'm starting to get cold feet about this whole subwoofer thing,
 

LOL

@navyachts you essentially have tone controls now. Turn up the bass level knob in the back of the ML woofer cabinets. 😂

@ricred1 sorry, I missed the point, are you in agreement with @rauliruegas ?

I'm starting to get cold feet about this whole subwoofer thing, There's so much conflicting information. Maybe tone controls are the answer...LOL!

rauliruegas,

" Pleaso do it you a favor and stay away of REL that it’s not a true sealed subwoofer but with a passive radiator that almost function as a ported one." REL No. 31 and 32s are true sealed subwoofers.

I wouldn’t sell any components if I were you. You may regret it.
Try a sub first from the dealer that has a good return policy (Music Direct, Upscale, Crutchfield). You can use the Coda preamp to drive the sub(s) if you have 2 RCA outs. See how it works with your preamp. 
Also…your dealer stating the woofers in the ML speakers aren’t fast he’s full of 💩 

ML finally, after many years, were able to get the panel/woofer integration correct. 

@audphile1 I see the Coda has 2 RCA outs (L/R) and the M1 only has 1 (L/R) out. Is it better to have the two outs if you're running two subwoofers?

Hmm, maybe I should I keep the Coda? 

The RELs leads hook up to the power amps speaker's output connections, but I think I have been talked out of RELs.

You can feed the sub from your preamp RCA out if you’re using XLR outs to drive the amp

@rauliruegas would this be sufficient alternative to the SVS SB16?

SVS SB4000

I was only considering the physical dimensions; it's a little bit smaller. Or would the 16 be the way to go?

 

@audphile1 Thanks, I will heed your advice!

@rauliruegas Thank you for the tips on the SVS SB16. I know with the RELs they prefer placement either on the inside or the outside of the main speakers. Do you think this would be the case with a pair of the SVS's or would I have to revert to the "Crawl Method" and place these where I find nulls in the room? I presume you also prefer wired subs over wireless?

The other subs I was considering were the KEF KC92s. Two 9" balanced forced woofers. Any though on these?

KEF KC92

@rauliruegas thank you for the compliments sir. 

A pair of Martin Logan Montis with powered woofers were the speakers I replaced with the Sabrinas.

I don’t disagree with what you’re saying. Problem is, every room is different. Every listener is different. What is OPs point of reference for bass? Is it a live concert? Is it the bass he gets in his car? 
Let’s keep in mind the high end speaker manufacturers have an objective to make the speaker sound as coherent as possible in a variety of rooms. That usually means they’re after accurate sound more than they are after blowing your wig off with bass. Quality over quantity  

As to Martin Logans they’re not easy to set up properly due to being dipole with powered woofers. I’ve heard several models including 12A and 13A in different rooms with diff components. There was no lack of bass.

Wilsons are difficult to place correctly as well due to time alignment - sensitive to placement changes less than an inch depending on where they are in a room. I can place my speakers to overload the room with bass. That’s easy. Most difficult is to find placement that provides coherent presentation. 
The only thing we can do is try to strike that balance.

Then there are variables such as type of music you listen to and recording quality. 

The M1 as network player. My Coda preamp is up for grabs as well. I'm using the M1 for that too. I like separates the most, but I want some decent subs as well, so it's a bit of a tradeoff.
 

I encourage you to spend a very good amount of time using the Bricasti network renderer before you sell your Aurender N200. I’ve used the M3 long enough to realize how crappy the network card is as a streamer (used as Roon endpoint as well as with Mcinnect). When I bought my N200 it just blew away the network renderer without breaking a sweat using the stock USB cable that I found in the Aurender box. I’ve gone back and forth many times and there’s just simply no comparison. 
I’ve also used the M3 preamp section. The Bricadti is excellent as far as DAC preamp sections go but it just doesn’t compete with a good preamp when it comes to soundstage layering and depth. The presentation is more natural with a preamp as well. 

I would just pick up a good tube preamp to use with the Coda amp. 
 

I owned CSiB and it’s an amazing amplifier (same amp as your No.8). It is fast, articulate, engaging and super clear sounding. No grain, no glare. 

I think selling your N200 to buy a sub is a mistake. Selling your Coda preamp gives you options - try a good tube pre ir get a sub. Just my opinion. 

@navyachts : Pleaso do it you a favor and stay away of REL that it’s not a true sealed subwoofer but with a passive radiator that almost function as a ported one.

 

In this link you can read about and the reference by REL on Home Theater use.

 

Here this could be your game:

 

SB16-Ultra Subwoofer | SVS

 

Btw this is not true about the ML subs on not faster enough:  " and that they are not fast enough for my speakers "

 

SoundStage! Max dB - Fast Bass, Slow Bass - Myth vs. Fact (06/1999)

 

R.

 

@rauliruegas great post(s) thanks. 

I was just about to purchase a pair of Martin Logan BalancedForced 210s and the guy, who is a ML dealer said that they are only good with home theater and that they are not fast enough for my speakers, He recommends a pair of REL S/812s 

Dear @audphile1  :  I like your Wilson speakers and the Boulder electronic that I already listened.

 

Even that your Sabrina is  IMHO better than the ML the subwoofer issue is the same as is the same the trouble with the Sabrina developed IMD and you can't change it in the way you posted.

 

Look from the same expert ( not an audiophile as us ) that I posted his explanation:

 

" 

TYPES OF "MAIN" SPEAKERS

In addition to all the above, there is the complex issue of the "main" speaker you are coupling to. There are essentially 6 types of speakers that exist:

1) sealed
2) port in the front
3) port in the bottom
4) port in the back
5) a dipole, which is a flat panel such as an electrostatic (Sound Lab, Magnepan, Quad, Beveridge, Martin Logan, etc.)
6) an true omnidirectional system such as the MBL or the BEOLAB 5.

Each of these speaker types couples somewhat differently to the room, and certainly to a sub in that room, and therein lie the problems in acceptable integration.

A port is ALWAYS nothing more than a cheap way to attempt to get free bass out of an enclosure and /or driver that's too small. It's a holdover from the 1930's when because of driver inefficiencies (especially when compared to today's units) you had to do everything possible to increase the useable output over the desired range of low frequencies.

At one level, all the guyz want 9 foot speakers in the living room (read "man-cave"). All spouses, of whatever gender, want tiny 3" speaker cubes that disappear, but expect 9-foot results from them. Since they haven't repealed ohms law or any other laws of physics while we were sleeping, the only way to get correct sound is to move a correct amount of air.

Lets examine ported speakers. We'll start with the worst case, the port in the front. At mid bass frequencies, say 50-80 Hz, the LF driver moves IN the cabinet, the air in the cabinet is elastic, and the port air moves out of the cabinet. Because of the frequency at which the cone is moving, by the time the cone moves out (forward) again, the port air is now moving out, so in front of the cabinet the two air pressure sources sum together and you get a fake bass "bump" or "boost".

As you go lower and lower in frequency, at some low frequency the air pressure from the LF driver and the air pressure from the port are exactly opposite each other, so they cancel, and there is no more audio at that frequency: it disappears.

When the manufacturer of a speaker cabinet defines the frequency response (i.e., 37 Hz - 20kHz +/- 3dB) this is what is defined by the entire arrangement of the port and the air in the cabinet and the driver. At some low frequency the port air is exactly out of phase with the driver air pressure and since they cancel, there is NO output from the cabinet into the room. Therefore with a ported cabinet, the entire sloppy concept is this juggling game between the response of the drivers under air pressure, the passive crossover inside the box, the port size and placement.

You must understand that ANY driver goes down to 0 Hz, or DC. If you put a battery across a speaker, the cone moves out and stays there. If you were to have a DC coupled power amp feeding a speaker - ANY speaker, from a 1" dome tweeter to an 18" rock n roll stage bass driver - and you put 4 Hz into it, it would simply move back and forth at 4 Hz. Of course in order to actually "hear" the audio it would have to be in the generally accepted passband of 20-20,000 Hz and the cone diameter would have to be enough to actually move some air in the room. So it is the overall combination of the driver size, the excursion, the box size, (therefore the air back pressure) and many other factors that determines the overall response of that "speaker" AS AN ENTITY.

That means IF you were to simply put those same frequencies through the mains and the sub (that means with no crossover, and this is the mistake that nearly everyone makes) you would now have 3 sources of LF energy and differing phase: the 'main' LF driver, the port, and the sub, all fighting with each other in the time domain. A further corollary is that since the air inside the [mains] cabinet is elastic, the phase relationship of the port air to the driver air is also a sliding one; that means it's "out of phase" — and smearing — over a wider range of frequencies than you might think.

If the port is on the back, again, a cheap attempt to use the back wave bouncing off a wall to give 'additional' bass, you have the ADDITIONAL issue of the transit time it takes for the back port pressure (already delayed because of the elasticity) to leave the cabinet, travel back, hit a wall, and bounce back around the front of the cabinet again; therefore this LF wave MIGHT be "in phase" with the front driver BUT BE 360 OR EVEN 720 DEGREES LATE; therefore it sounds like the bass frequencies are ok in the frequency domain but the IMPULSE RESPONSE is now muddied.

Also, in the case of back ported or (type 5) dipole speakers, since the path length from the back of the speaker to the wall and bouncing back around to the front of the speaker is a fixed physical entity, at some frequencies you are adding and at some frequencies you are canceling: you have simply made a physical/mechanical frequency comb filter that you can't do anything about. Sound Lab's answer to this (for use with their flat panel electrostatic speakers, which are dipoles) is they sell you a "Sallie", which is an absorber to absorb the entire back wave output of the electrostatic panel. Since now there is no comb filtering; all you are therefore hearing is the front signal.

PORTED SUBS

A ported sub for home use is even more wrong than ported mains. Now you would be attempting to acoustically add together in the room at least SIX low frequency sources with differing phase and frequency slope conditions: the LF drivers in your two mains, their ports, the sub driver, and its port. In addition, since it's a bandpass it cannot go down low enough for serious Home Theater effects. (that typically means a real 20Hz or close to it.)

In some cases such as a bandpass sub used in a club or on a modest-sized stage in your local pub, you are most concerned with efficiency and not with getting frequency response "flat" down to 20 Hz; therefore a correctly set up bandpass box that might roll off at 35 to 45 Hz is quite sufficient and also very efficient for the defined purpose. And again, as a point of reference, "flat" response in the frequency domain is FAR AND AWAY the LEAST important phenomena: impulse response in the time domain is the most important, but it cannot be measured with a handheld meter therefore almost everyone simply ignores it. If you're interested in learning about the newest (and evolving) pro sound system / stage methods of "steering" bass, Dave Rat has some very cool videos here:

part 1  www.youtube.com/watch?v=VwLH7zP6Lwo

part 2  www.youtube.com/watch?v=B-3pURYOwfw

part 3  www.youtube.com/watch?v=aSZK9Altvm8

There's a nice article here:
www.prosoundweb.com/channels/study_hall/tech-topic-friends-in-low-places

But back to our Home / HI-FI / 2-channel / Audiophile / Surround Sound systems: There is ONLY ONE truly correct way to "add a sub" to a system in an controlled listening room situation: you must correctly cross over the 2 sealed cabinets; and their timing must be correct. ANY other method will lessen the focus and clarity and imaging you have tried so hard to preserve.

I have many clients and customers with extremely exotic high-end 2-channel systems that are all chasing the holy grail of 3D holographic sound imaging, and until they follow my distinct guidelines they are never completely satisfied with the results.  "

 

Audiophiles as us and MUSIC lovers as us need to have as a fact it's a MUST to have or  develop an EQUILIBRIUM between OBJECTIVITY and SUBJECTIVITY

in all our room/systems decisions to achieve the best overall quality MUSIC level performance that puts us nearer to the recording and NO it's not other " road " to achieve that target but all these is each to each one of us and not what I said.

 

Please read this link and even the whole thread:

 

https://forum.audiogon.com/discussions/do-you-think-you-need-a-subwoofer/post?postid=310058#310058

 

R.

@rauliruegas OK, will do, thank you! I was looking at the BalanceForced 210 model by Martin Logan as they may be easier to integrate with my mains.

Dear @ozzy  : I respect your opinions.

 

" Running the main speaker’s full range and augmenting the lowest frequencies with the sub(s) is the best of both worlds. "

 

Unfortunatelly it does not exist those " both worlds " and probably you don't understood what I posted about that very high ML crossover 300hz frequency that procuce a very high Intermodulation Distortion that contaminates all the ML quality response.

What that ML is doing is to develops " trash "allover the MLspeakers through that severe IMD.

When that " trash " is out of that ML woofers then the midrange, midbass and high frequency ranges now arepristine, with clear sound, nearer to the original signal and shiny all that system as never before:NO MATTERS WHAT.

 

@navyachts  deserves the best from his room/system.Btw, Velodyne is not the only subs that can help you inside your budget.Only look for a sealed subwoofer design.

 

R.

@audphile1 

 What do you have in mind for a source to replace the N200?

The M1 as network player. My Coda preamp is up for grabs as well. I'm using the M1 for that too. I like separates the most, but I want some decent subs as well, so it's a bit of a tradeoff.

Running the main speaker’s full range and augmenting the lowest frequencies with the sub(s) is the best of both worlds.
 

@ozzy +1

subs used to boost bass will just completely break a good setup 

 

@navyachts definitely try a sub but I’m surprised you’re selling your Aurender. What do you have in mind for a source to replace the N200?

@ozzy 

That is why I suggest first finding out how low your speaker will actually perform.

OK, I still have to figure out how to do this first.

@rauliruegas 

Velodyne - DDP-10+ - Digital Drive Plus 1250W Active Subwoofer

At $5,600 each, I think these are out of my reach at present but thank you for all you help and suggestions!

 

@audphile1 Did the 4 feet, flashlight, can't get more than 72" separation and running the DAC at your suggested Minimum 0. Sounds good but I still may try a sub. Trying to sell off some gear in order to do so. Daughter still has 1/2 left to go at university! if you know of anyone looking for a super low hour, pristine condition Aurender N200, let me know!

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. 

@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. 

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.

@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!

 

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.

@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!