High quality subwoofer - which one?


I’ve owned my C4’s for about six months now, and they are excellent. But, you can’t ask a speaker to things it isn’t big enough to do. What that is, is to go FLAT to 20 Hz. The Vandersteen Quatro’s had built-in 250 watt class B powered subwoofers that are to die for once you hear them. The blemish on the Quatros, and it is a small one, was the slightly veiled lower midrange. The C4’s are absolutely seamless everywhere they go. The lowest bass can be fixed and most would probably say it’s not even necessary...until you hear a real sub system that is. Once you hear the effortlessly smooth low-end of a dedicated sub woofer you just can’t forget about it.

I started looking at subwoofers, and they are expensive, but relative to what this hobby’s cost(s) can be on some item(s), they are affordable. Well, ONE is affordable, anyway. I have three models that seem to all be nice products, and was curious what the feet on the street have used and your likes / dislikes. One model that I have not included needs an external hi-pass filter and I may be dismissing this model out of hand…and shouldn’t be and if you use this model, convince me.

I have a pretty large room (16’ wide x 40’ long x 8.5’ high (ceiling is split at 7.5’ and 9’)) so a bigger sub may be needed. Right now, I’m thinking ONE sub crossed-over pretty low. The C4’s do go pretty deep, but I probably agree that two would be “best” but expensive and the narrower room might make double placement hard. One is a snap, between the speakers away from the wall or near the right corner. I do not play “loud” (80-85 dB SPL average based on my radio shack SPL meter) but still like the smooth deep bass of a sub. Crazy loud isn’t the issue, but the sound quality is.

The choices are mind boggling in cost (JL Audio in mono or stereo) or mono (VELODYNE DD15+) verses stereo (SVS PB13 Ultra) set-ups at the same price. I have three options below to illustrate this.

The set-up that seems too expensive but outrageously good;
JL Audio Fathom f113 - $3600.00 / 13” / 2500 watts peak class D amplifier / sealed box.
But the sub needs a high-pass Cross-over like a Bryston 10B-STD @ $3,500.00

This is expensive compared to the SVS, but is it better than TWO SVS units?
Velodyne DD15 Plus - $4,000.00 / 15.0” / 1250 watt continuous class D amplifier / sealed box.

This seems like a good price but is the product good enough even if the price is? Use TWO of these in place of one DD15 Plus?
SVS PB13-Ultra - $2,000.00 / 13.5” / 1000 watts continuous class D / ported box.

So what have we done with subwoofers and why? This got real complicated real fast. Ported, vented, stereo at the same price as a mono sub ETC. The odds of auditioning these monsters are about zero as you hear the room. My room seems to be pretty good down low based on my Quatro set-up with powered subs. If a decision isn’t easy, I’m missing something…a lot of something’s it turns out.
rower30
Rower
I asked Mr Vandersteen if the eleven Band Eq could be added to the 2Wq's a little over two years ago and he stated someday then I found this statement sometime last year:

Paul (7/19/11): Have you considered adding the 11 band "room compensation controls" to the 2wq so it could be adjusted the same way as the subwoofers in the Quatro? How much would this feature add to the cost of the 2wq?

Answer: HELLO PAUL, THIS IS IN THE WORKS BUT IT WILL COST MORE. IT WILL BE AN ADVANTAGE BUT NOT AS GREAT AS IN THE QUATRO, FIVES AND SEVENS BECAUSE THEY NEED TO BE PLACED WHERE THE IMAGING AND STAGING ARE BEST WITH BASS AS A LOW PRIORITY. THE 2WQ CAN BE PLACED IN THE CORNER WHICH IS THE MOST LINEAR LOCATION IN MOST ROOMS AS LONG AS THE WOOFER IS CONTROLLED ENOUGH SO THAT IT DOESN'T BOOM (VERY FEW).

Like you I've felt that the Eq on these would be most beneficial but will have to wait for the results. I seen that you posted a question on the Vandersteen Q&A but was a little confused by the answer, I hope he hasn't given up on the idea.

Good luck
First, Vandersteen INCLUDES all those "nasty" EQ settings on the Quatro, 5A and model 7 (not much is better than product). Done right they are excellent. Two, a subs response is the ROOM it is in on. Yes, the floor standers are positioned for best imaging, not bass, so "more" EQ may be needed. But, that does NOT mean that a top flight sub should not offer some room EQ. This isn't harsh, it is what it is...a user feature to maintain a better overall response.

The feature has been built-in to all three Vandersteen models, and could be added to the subs, too. The problem is, according to Richard, that we are too cheap to understand the feature, and buy more on the price. Yes, the sub is located more consistently than the mains but still, you can only move two eighteen inch boxes around so much before the living room is the stereo and there is no place left to live! EQ helps avoid this.

Most subs roll off the bottom at 12 to 24 dB / octave to remove "junk". The top is a first order filter at 6 dB per octave...as is a high-pass filter. More than 6dB per octave would make blending real hard.

Actually, full range passive speakers are the WORST way to get quality sound. Most of the power is eaten-up in the crossover with pads to keep the little guy drivers from frying. And, each amp design is ideally very different for each driver. There is just NO WAY a "full range" speaker, even a C4, can be accurately dynamic and flat with the box size and power necessary to play flat and dynamic below 40 Hz. The C4 crosses-over at a high 730 Hz into the eight-inch drivers, so the two eight-inch drivers are playing a LOT of midrange information. Yes, the two help limit driver motion and intermodulation distortion, so they sound real nice. And I'm glad they biased the speaker this way. But, the bass is NOT as deep, flat, or dynamic as a powered sub system. The best world is with each driver using it's own amp, through an active crossover...things could be VERY different with the exact same speaker.

So, I feel that there is no way a "soft" crossover using just EQ is going to be as good as a true first-order quality hi-pass filter. You have too many things left on the table; main amp is still taxed too much, bass driver have much more intermodulation distortion than necessary, the subs "sound" doesn't take into account the main amps sound with line-level inputs and you don't have much control of what it is (with true active cross-over systems you can PICK the amps you want for sound, even all three the same). Amd. stereo is better at dynamic range and smootness all thigs the same. Things aren't the same, so is ONE SUB1 better "sounding" than TWO Velodynes that may be "smoother and more dynamic? I may never know.

Yes, I've asked Dynaudio about their newer sub 800 series (which has a high-pass). No response from the main camp yet.

I have ruled out ported subs as they have two large phase peaks in the pass band, and can't be a linear as a seal system can be. LOUDER, yes.

The market is just thrown-in the towel for true Hi-fi sound with hi-def TV. It's just that simple. Digital music is trash, and shouldn't be! 24-bit has failed to bring music to the public due to infighting over getting a square deal on production (and they should) as we all go to FREE lossless CODECS (FLAC). Something about the word FREE makes it hard to run a business. The technology should make meeting BOTH demands easier than before, but vendors are driven to distraction to make money for stockholders and not the hi-fi customer. A nickel spent the wrong way (hi-fi) is taken from the bottom line. Their eye is on the ball, it just isn't the one telling you what note to sing playing music.

Right now, the 2Wq Vandersteen sub makes the most sense design wise IF he adds the eleven band EQ feature. If Richard did this, I would RUN not walk to the nearest dealer and by two. It cost money to do this, and for what he sells to true Hi-fi enthusiasts, it just won't pay him back to do it. I'll bet he'd do it even-up! But, he may not even get there. It's a shame, too.

Look at this thread. I've spent hundreds of hours learning the ins and outs of subs. If we all really did this, and really understood what was going on Richard would have a reason to "upgrade" the 2WQ. In the old days, people worked things harder before we bought things, as stuff was not designed to be thrown out.

So, my position is do I use 2Qw's and "hope" I can use them anywhere I go with decent room response and placement and with different speaker, or go with a more flexible but technically not as "sound" a design that has EQ capability (SUB1 or Velodyne) and that sounds maybe more consistent where I want to place it? But if Richard would remove that gamble of room EQ, sign me up now!

You are all great. This has been a fun thread, and I hope we all learn from it. And, since this is hardly an easy decision, I'm glad to see people aren't condemning decisions made by others. Heck, I may have to make a decision and not even HEAR a product I buy let alone all the other! How on earth can I say negative things about a product other than off a design spec? Yep, all I can do is try to "improve" the STD deviation around a guess with a "best" design practice metric limiting my choices. Yes, the “best” product may fall out! So still, that is no guarantee. There are no dealers nearby that will loan, or have, two 120 pound subs (I weight 150 pounds...the sub wins!) to try at home, I called around, let alone even hear. One dealer told me to bring my own laptop and set up the subs myself! I guess PINKIE runs the store and the BRAIN is the customer? That’s no way to rule the world. More than likely, a dealer that wants the business, and sets up the product right will get it. I know only one store that does this, and they sell Vandersteen, so this makes it all the more harder to not reward that dealer and accept the gamble the EQ doesn't matter.

04-11-12: Erndog
Johnnyb53- My experience is that everybody has an opinion about everything and so I take it with a grain of salt. The experience I trust is when I try different things and to hear how that sounds in my system with my ears. Only you can say what will work best in your system.

Absolutely right. Barry is probably playing the odds as far as what generally works well, but there are so many variables that in the end you have to match the sub to your speakers, your room, your speaker and sub placement, etc.

For example, sealed vs. ported mains: sealed speakers have a 12 db/octave rolloff; ported ones something more like 18-24. Which one is easier to blend? Depends on the sub's crossover point and curve. Ported? Front or back? How close to the wall? If rear-firing port close to the wall, Barry's right. If front firing and the speaker is out from the wall, you can probably get a good blend. As you point out, you can damp or plug a port but don't know if it'll hurt or help until you try.

I've heard sub integrations with a high pass to the mains and others without. Sometimes the high pass is better (e.g., to the B&W PM-1's with 4-1/2" woofer) and sometimes without (Magnepan 20.1 or my Mirage OMD-15).

Have you thought about a Dynaudio Sub 600? Claimed freq response is -3dB at 18 Hz and includes a high pass filter settable to 60 or 80Hz or bypass.
For erndog and rower:

The NHT is a very good unit. I used it with my Velo SMS-1, because I wasn't crazy about Velodyne's internal hi-pass. The NHT is pretty much transparent (to my ear, anyway),really flexible, and reasonably priced
Hi all ! The Vandersteen's are excellent speakers . With that being said , if it were me I would make sure my speaker positioning was absolutely perfect . I have always preferred no sub and a well setup system vs any sub . Hate to rock the boat here but Imho subs are better for movies . Good luck whatever you decide .
Johnnyb53- My experience is that everybody has an opinion about everything and so I take it with a grain of salt. The experience I trust is when I try different things and to hear how that sounds in my system with my ears. Only you can say what will work best in your system. For me, I definitely wan to try what Barry recommended. Right now I can't afford the Bryston, so I did some research and found a couple other high pass crossovers that could do the job. NHT X2 (discontinued, so what have to be a used model) or HSU High Pass Filter for $100 new.

Rtilden- Barry also told me about using sealed mains. I experimented by plugging the ports in my Tylers and didn't like how it sounded, so I'm keeping the ports open. Those Woodmeres are monster speakers and I'm sure they have a huge soundstage. Good luck with the Rythmik sub.
Rower,
With remote subwoofers.........one has the ability to position them to counteract room modes, suck-outs etc and achieve the strongest bass performance at the listening position.
With subs attached to the main speakers.......there is not that same ability and positioning the main speakers for imaging and soundstage becomes.......quite rightly.....the main criteria.
This unfortunately is rarely the best location for subs in most listening rooms hence the need for some form of equalisation for the inbuilt subs to ameliorate this compromise.
To say the Vandersteen remote sub is "out of date" because of the omission of equalisation is therefore rather harsh I believe.
If you were to hear the purity and transparency combined with the foundation depth available with the 2Wq subwoofers.........you may not desire any further electronics placed in the signal path?
I certainly don't :^)
Erndog:
I received the same recommendation from Barry, and he added that using sealed (non-ported) main speakers was also very important. I am using Tyler's Woodmeres, which put out ample bass, but in my large room (30x30x12), I think my symphonic music could use a little bolstering on the lowest passages. Currently, I am considering a single Rythmik F25. I have only one spot in the room for it, so it will have no opportunity to be placed in the perfect spot, acoustically speaking. I don't think I have any way of determining its success other than to try it. With twin 15" woofers, it stands a good chance of working. Let us know how things go.

I ended up contacting JL Audio tech support to get more detailed information about setting the sub up for optimal performance. I was told by Barry that playing speakers full range and crossing the sub at the lowest octave would result in mish mash. He indicated that the best way to do it is to cross the sub at 80 hz using an external crossover, thus freeing up the main speakers.

I think he's overstating the case. The lack of a high pass filter doesn't necessarily result in "mish mash" any more than a 2-1/2-way speaker system results in mish mash. It's the same principle at work. There are many exemplary 2-1/2-way systems in which extra woofers are brought in to reinforce an essentially 2-way speaker system without high-passing the rest of the system. Many 2-1/2-way systems are famously well blended and coherent.
Halcro,

Yes! That's exactly why I want to go stereo. Remember that the article was done in 2000, and Digital Room Correction was not really available at all. So the room was really making a Vandersteen subs a variety of different products in each room!

WHY he has not updated the subs too include digital or manual EQ like he has in the Quatro, 5A and model 7 is beyond me. Yes, yes, yes this is a great sub EXCEPT you can't get near what you need in room EQ compared to today’s EQ'ed products that can be set-up "right".

It seems that the JL Audio and Velodyne are all CLASS A rated by many sources. The Velodyne offers far more flexibility in set-up. True, it is like a road map, the only roads that matter are the ones you end up using (and it may be the full range set-up road with no high pass!) I can contrast and compare both methods with the Velodyne.

But yes, the SOUND is so hard to argue, I haven't heard anything. My Quatro was great (but it was EQ'ed to my room!!) so the Vandersteen sub is out of date to even his current knowledge.

And yes, the C4 is flat to about 45Hz in a real room, yet it has "response" to 27 Hz without doubling. It is NOT nearly strong enough (flat) down real low to hold nearly the dynamics of a powered sub system let alone be FLAT at 25 Hz! This is reality. And, any driver playing lower midrange with large cone excursions will have a LOT more intermodulation distortion, this is also a reality.

The good news is, DRC has allowed users to set-up subs to properly sound the bass, very much unlike the old days.

So if I KNEW the roads on the map I need (full range and blended subs verses the high-pass option) it would open-up or remove choices. As big a pain as this is, I'd rather error on the side of choices, which seems to be the Velodyne. And yes, this is all metal arithmetic right now...drat it!
This is a very interesting thread because I'm also dealing with similar issues, so the information here is valuable.

Let me throw in my 2 cents. I have Tyler Acoustic Linbrook speakers w/bass modules and I've measured their response in my room to go as low as 35-40 hz. I also have a JL Audio Fathom 10" sub. I ended up contacting JL Audio tech support to get more detailed information about setting the sub up for optimal performance. I was told by Barry that playing speakers full range and crossing the sub at the lowest octave would result in mish mash. He indicated that the best way to do it is to cross the sub at 80 hz using an external crossover, thus freeing up the main speakers. He said to conceptually treat the sub and mains as a two-way system. The sub being one way and everything else the other way. That leaves the Bryston that was mentioned earlier as a key component, albeit an expensive one. Barry also put a plug into his own external crossover he is developing for half the price as the Bryston, but it's not avail yet. Here is his website that explains more about getting a sub dialed in: http://www.soundoctor.com/whitepapers/subs.htm

One more thing, if I had to do it over again, I would have gotten the 12 or 13" Fathom instead of the 10". The 10" doesn't have enough muscle for some of the powerful classical music I listen to.
I've heard and implemented a fair number of subs with both stereo and 5- and 7-channel surround. I have four subs active in my house right now and implemented two different subs over time on my neighbor's 2.1 system.

Based on the subs I've heard, if you can afford the JL f113, get it! Bear in mind that as good as a single JL sub is, two are better. I heard a setup of Maggie 20.1s flanked by a pair of JL F212s and the integration is seamless.

If you're doing 2.1, especially with something that can handle the dynamics and power handling of your Dynaudios, don't obsess over sending a high pass signal to the Dynaudios. You will get a smoother, more musical blend if you simply let them run full-range and use the sub(s) to fill out the bottom octave with the sub crossover set at 30-50 Hz depending on the speakers' capabilities and the room's acoustics. The C4s spec down to 27 Hz and power handling is rated at 400 watts. They're big boys designed to handle full-range signal even if they don't give you all the sub-30 Hz output you're looking for. When you're adding a sub to mini-satellites with 4-1/2" woofers, a high pass filter makes some sense, but for C4 floorstanders, not so much.

In home theater I *do* use high pass to the surrounds, but that is for handling the dynamic range of effects soundtracks--explosions, crashes, etc. For a musical blend, you're better off not adding yet one more network filter to the signal sent to your mains.

Given SVS's 45-day eval/return period and one-year full-credit upgrade program, you might want to start with a pair of SVS's and see if they give you what you want. One nice thing about the SVS's you're looking at is that you can choose any one of four different low end rolloff profiles depending on whether you leave all three ports open or use the supplied plugs to stop one, two, or all three ports. You may find that plugging all ports gives you a smoother low end curve and more ultimate extension for music.

I have a friend who uses the sealed compact SVS with his Maggies and he's very pleased with it.
Yes, I'm still not fully appreciative of a single sub. The L+R summed info can cancel detail a stereo option won't.

The real direction the market has headed is just the home theater LFE channel option, which is a dedicated summed source, and was never stereo to begin with.

True Hi-fi subs are STEREO on L / R are NOT the same information! This is why true separate subs seem important. And, if you argue L/R differentation it isn't right, you're "wrong" but still overall right as two subs is still better than one for dynamic range and smoothness.

I like the general concept of the Paradigm SUB1, but can't get past a mono sub in my head. It's too expensive for two! And, you lose all the application options (full range verses high-pass option with the Velodyne) so you're stuck losing part of the advantage of using subs, to remove the load off you main speakers. I just can't figure out how this concept is "dated" by DRC software. For HT maybe, but not hi-def stereo.

So right now I'm;
75% two x Velodyne 10 Plus.
25% one x Paradigm SUB 1.

I appreciate everyone's input. Crowd sourcing the answer is usually a better answer!
This article by Richard Hardesty convinced me to buy the Vandersteens
2Wq
Regardless of the brand of subwoofer......this is quite a valuable article IMHO.
Rower,
Your last posting on the single Paradigm sub seems to contradict your valid (IMO) penultimate conclusion on the benefits of multiple subs does it not?
Having lived with a single REL Stadium II subwoofer in my system for 10 years (running full range and high-passed)......and now having had the two Vandersteen 2Wq subs for five years.......I would never go back to a single sub. Nor to REL unfortunately.
I would second Marty's approval for the pair of DD 12s.
Your analysis and reasoning skills appear quite impressive to me :^)
Good luck.
Rower,

I'd say that your argument for a pair of DD 12s is pretty convincing. I'll go out on a limb and suggest that - if you do pull the trigger on that combo - you will be very happy with the results. It's not the specific approach that I use, but I think it's a very, very good one overall.

Marty
More info;

I talked with Paradigm about their SUB1 at length and, a friend who is a overseas representative. So, there is "some" bias, true.

But, the SUB 1 has some very good points about it.
1.0 Three directional driver groups melt to a location smoother than one front firing driver. Some say this is less than more of an effect.
2.0 Smaller drivers are very fast.
3.0 Paradigm does seem to have the very best auto EQ on the market, one that really works.
4.0 They say the sub 1 is specifically designed, like most non high pass subs, to work with existing speakers full range, the more full range the better. I'm slowly starting to accept this premise with amazing digital room EQ.
5.0 ONE of these is EXPENSIVE, though ($4,000.00). But, the last major point is that phasing information is above 40Hz or so, and on the C4's I'm told it will set itself in nicely pretty low, so one sub isn't effecting imaging with this full range speaker, or others flat to 40 Hz in room.

Wow, what I ride on subs. I'm off to listen to this thing this weekend. It does seem to be a tidy and accurate sub, with good press, and a good match to the C4's (on paper so far, anyway).

Any good flack to come my way on this choice?
New info so far;

REL and Vandersteen use a similar approach, but they BOTH lack any sort of in-room EQ, that is critical to performance. Great HP system and signal integration system on the Vandersteen, though.
-Vandersteen Quatro series speaker on up uses the same clever integration system as their subs, but add eleven band EQ. I wonder WHY this is not on their subs? It is essentially the same system, and they KNOW IT!
-REL is old school move it till it works and HUGE cabinets to get low-end response. Yes,it can sound good but you have no real room for two ported subs. And, they don't High Pass the signal. Somehow, REL seems behind a generation of room EQ. You may get it to sound good, but will you like where it/they are?

Too bad the Vandersteen doesn't have the eleven-band room EQ, I see this as a major goof that was developed in their upper speaker line. I wonder what gives there? So again, they seem behind, too.

The Paradigm SUB1 seems good till you realize it gives up the stereo option at any where near a reasonable price, especially with no real HP option that is affordable. The Sub1 is MONO and EXPENSIVE.

I'm not a proponent of running the C4's full range "over" a sub's response. You would never make any speaker this way so why splices one on top of another for the bass? It makes no sense to me other than HT / LFE doesn't care as much about accuracy.

That said, I've looked into STEREO placement and the time and phase information differs from channel to channel, so stereo (true right and left channel) subs is the way to go. It seems too many people neglect the differences between true right and left and just go for sound QTY. Two 10 inch subs offers more area(157 in SQR) than one 13.5 inch sub (143 in SQR)and faster transients, too. You lose a touch of REALLY deep bass, but should more than make up for it in stereo imaging, response and room smoothness. Dynamic range isn't a problem with two 10" subs.

The price is about the same for two smaller Velodyne DD10 Plus subs as one DD18 Plus. The stereo option is just too compelling to give up. And, the Velodyne brand will let you either go full range or High-pass at 100 or 80 Hz removing the C4's from low bass duties improving intermodulation distortion and imaging precision. To me, that is more important than 4 HZ on the bottom end or a few extra dB of headroom as I don't listen HT "loud".

So far it seems to be the DD-10+ or DD12+ x 2. You get;
Ability to high pass OR run full range.
Room EQ option (manual works great).
True stereo at a reasonable price.
Smaller size with a sealed box.
Good reputation for sound.
Great looks.

Talk me out of this.
I forgot to mention purchasing Velodyne. It seems Velodyne has scaled back its dealer network somewhat in favor of direct sales. Velodyne warranty parameters and current MSRP should be reviewed on the Velodyne website. Also, the quality and fit and finish of the Plus series is unquestionably superior to Velodyne's previous Digital Drive series and is clearly an entirely new model.

I did compare the 18 and the two 12's and there is no denying a difference in the presentation of the two. Relying on the software display showed a flatter uncorrected response in the 30-40Hz range with the two 12's (the crossover area between the mains and the subs). It's difficult for me to effectively describe the corrected differences between the 18 and the 12's. Briefly, the 12's created an even wider stage with more snap or speed while maintaining a seamless integration with the mains.

This area of integration is were I had difficulties with other brands of subwoofers that I auditioned in my room. These auditions were done two to five years ago and I'm sure changes to some have been made since. Most were done using the first generation of Digital Drive software to more quickly facilitate location and EQ.

I purchased mine from an out of network local brick and mortar which I have been doing business with over the years. I purchased new and the store offers their own warrantee with non factory repair. In my case the savings over MSRP and shipping for repair would allow me to pay for factory service as I live about forty miles from Morgan Hill, California.

There are many out of network retailers that offer Velodyne products if you're so inclined to forgo the manufactures warrantee in lieu of a lower price.
I'm using two Velodyne DD-12 Plus' to fill the bottom octave of my Avalon Acoustics Eidolons. These 12's replaced a first generation DD-18 in a 27' x 46' vaulted ceiling room. The Eidolons are located using the reflective thirds method suggested by Avalon with sound staging as the priority. With this much space around the speakers there is little need to control their bass response so I use the line level inputs on the subs.

The 12's are positioned to the outside of the speakers approximately eight inches forward. I recommend using the Manual EQ Optimization for at least two of the preset parameters. Once familiar Manual EQ takes about twenty to thirty minutes. There is enough flexibility within the Manual EQ to create a seamless integration with the main speakers.

In hindsight two DD-10 Plus' would be more than sufficient. The remote volume control allows for listening position adjustments of individual recordings.
I have also had success with a single REL (older Q150e). It really loads my room up nicely and has lots of adjustment/tuning options. At this point I would never NOT have one.
Rower,

WHAT pray tell smooths out the C4's room bass response?

The obvious answer is "nothing". Most folks who run the main speaker full-range simply fit the sub's response "under" the rolled off bass response of the main speaker and live with the same ragged bass FR they had before adding the sub - they just get more extension, "air", etc. The point of this approach is to leave the main speakers' response intact. I think that this is rarely the best idea, but many others here disagree.

In any event, manual adjustment of the subwoofer's FR via parametric EQ (Velodyne DD) will let you really customize the fit as you "snug up" the top of the sub's output to the bottom of the mains'. I have run the Carver Cinema Ribbon Monitor (which have very little response below 100hz in-room) full range with DRC subs and gotten pretty good results. (Obviously, your C4 is a somewhat different animal than the CRM.)

But there is another approach, albeit one that is not ideal for a speaker that has extended bass response: You simply overlap the the sub and the main speaker up to a desired x-over frequency.

If you do want to try this approach with your C4, you could (depending on the DRC solution you choose) face different issues:

Full range DRC (ala Audyssey in an AVR) will smooth both sub and main until the "hand-off" is smooth. There should be no issue there.

Sub specific DRC (ala Velodyne) will allow you to attempt to manually "mold" the subs' response around the C4's output in the bottom octaves. That is, during set-up, you will see a video display of the summed bass response of the C4 run full range and the subwoofer. You adjust the sub via a combination of master sub volume level, placement, phase and (perhaps a touch of) parametric EQ such that you get enough subwoofer output to smooth all meaningful bass nulls. You then EQ the peaks via parametric attenuation until you have the smoothest possible overall FR below the sub's high cut frequency.

I can't swear that this approach will work well in any given room with any given sub/main combo, but it might work with some combos in some rooms. I'd recommend it only for those who REALLY don't want to interrupt the main signal path.

As I've indicated above, I definitely prefer to low cut the mains - but I described this "pure path" alternative to illustrate that you might be able to use DRC for the subwoofer without "corrupting" the sacred source->pre->power-> main chain. Not the way that I'd do it, but you could try.

Marty

As to optional high cut units, it sounds good, but you'd have to build a workable business case.
The Vandersteen 2Wq subs come with a high-pass filter.....which IMHO......makes a huge difference to the headroom available for the main speakers.
They have three 8" woofers per sub driven by its own 300 watt amp.
The passive W2 high pass filter is good.....but the active W5 is just better (and able to be adjusted for impedance matching).
Two of these subs can be made to blend seamlessly into most rooms and as they are sealed (rather than ported) boxes.....the bass is tight, fast and tuneful.
I love to hear that the high-pass isn't needed but...

If I use the C4's full range and use the digital room processor function on the sub, WHAT pray tell smooths out the C4's room bass response? It seems like the mish-mash of the C4's and the sub would be unmanagable...and the advantage of limiting intermodulation distortion would be lost.

I thought that this was "AUDIO" and not an LFE web site. Yes, movies are fun, but I use a high-end AUDIO system for 2.1 (or will be once I get all this sorted out). I'm not being mean, but MUSIC is my main objective not sound effects.

I agree subs are probably HT biased, but the one's that are "supposed" to me music biased seems to me should offer a quality HP filter system as an option, or outboard option. Why KILL audio 2.1 or 2.2 buyers? OK sure, make it at least an option!

So I seem to be stuck on the Velodyne DD-18 Plus / JL Audio Fathom f113 or the Paradigm SUB1. The Velodyne has a High-Pass, so I can go either way with it. All are expensive, but they seem pretty good. The SUB1 probably is the best "active" EQ unit where the DD-18+ is pretty good if you use the manual EQ and learn to cut peaks and leave holes alone if a few dB of boost don't fill them.

Still, I'm learning. The REL seems like a good idea (witness Vandersteen's powered speaker internal sub solution)that I know works. I need to look into this product.
Hi Marty. You're likely correct, but I use my AOS (Art of Sound) sub with the speakon connected to the center channel taps to make it a large speaker in my HT setup. You'd be amazed at how much LF info is in the center channel in action movies. Many enter channel speakers are so limited.
I believe that the reason that integrated high pass crossovers are disappearing from subs is simply economic. As you note, the high pass is redundant for HT use which - just guessing here - completely dominates the market for subs at any price. Then, within the small group of customers seeking high end subwoofers for 2 channel use, there's probably a fair chunk that prefers to use a separate x-over (Marchand, etc) anyway.

Including a high quality high pass unit integrated into the subwoofer surely increases price for a feature that has little value to most prospective buyers.

As to the "Do I or don't I?" high pass question, I think it comes down to DRC again. If you use DRC, you might get really good results either way. If you don't use DRC, I say high pass. I know that many other 'goners disagree, but I believe that the biggest advantage of subs can be heard in the smoother FR between 50hz and 75-125 hz (depending on the room) where room interaction is dominating very important musical info. For me, anything below 50hz is just icing on the cake - tho I will admit I do like that icing!.

In a DRC system, the software can do the heavy lifting. In a non-DRC system, your subs can go a long way toward smoothing response in this area....but only if they're crossed high enough to handle the bandwidth in question.

Just my preferred solution.

Marty
I' m also looking for sub to integrate with my C&C Abbys. But I'm looking for one with a speakon connection to the speaker taps. REL and AOS are the only ones I knw of. So far a REL 201 is my first choice.
OK, we're getting some good info. Right now, I'm REALLY confused why top of the line sound quality subs do not have high-pass filters for 2.1 or 2.2 systems (or sell one). Everything seems to be for home theater gears high pass electronics that is NOT as good sounding as my RLD-1 platinum pre and KISMET amplifiers that I WILL keep using! So much for my rant, back to physical reality of what's out there...

The "sound" is related to the high-pass filter, so it seems that top-flight vendors would want to control that effort to hold quality. Sure, a sub made for LFE home theater doesn't really have to be a good "music" sub. But, the one I buy does have to be MUSIC more than LFE. This means some options will require a high quality low pass filter. I know of ONE, the Bryston 10B-SUB. Still, $4,000.00 for a crossover? If I go this route, and buy a sub and the cross -over, the economy will change throughout the world. When I bought the C4's it improved to where it is now!

The Velodyne DD 18 plus would be the single sub choice based on cost / performance as it has a high-pass filter...so I can use it any way I want. They say the DD 18+ is the most expensive sub out there, but it IS NOT for true 2.1 users! Yes, maybe for home theater guys and gals it is who use HT pre-amp. Subs that need a high-pass filter (unless I can be convinced that this isn’t so) are really WAY, WAY more expensive to use in a 2.1 system.

1.0 If I cross-over low enough, I don't need a high pass cross-over?
- Some have said, elsewhere, that the benefit of a sub is to take intermodulation distortion out of the speakers and get it to the sub, improving clarity and dynamics. I'd probably not get this benefit running the C4's full range with a sub X-over set about 40 Hz or so as the C4's cone excursions aren't reduced.

2.0 Most seem to think an 80 Hz low pass frequency is a good starting point...with a high pass filter (Velodyne DD18 plus allows this). And, this removes big cone excursions from drivers playing mid range information, improving clarity.

Talk to me more about the use of a high-pass filters (or not) with subs. The manuals for the subs are TERRIBLE at set-up configuration details. I've read them all and there are nothing but questions in my mind. Does modern sub digital room compensation INCLUDE the output from your main speakers running full range while you EQ and tune accordingly? Older technology that could not do this REQUIRE a high-pass filter?

ANOTHER SUB SELECTION;
From another angle, the Paradigm SUB 1 is a three sided driver arrangement that "spreads" the room loading in three dimensions smoothing the response of a single room position sub. And, it has the output of two 12" drivers using six eight inch drivers. The digital EQ is reported to be VERY, VERY good. But, this sub doesn't have a high pass filter, either. The to be or not to be high-pass filter question remains.

What's so odd, is that the sound you EQ (The C4's and my Quatro are about the same on warble tones, 77+/- 5 dB variation from 20-100 Hz, but the Quatro has it all over the C4 playing actual music. A speaker that is INACCURATE on warble tones and ACCURATE on DYNAMICS would seem to sound better than a speaker that is ACCURATE on warble tones but INACCURATE on dynamics. BOTH would be super. But, the trade-off in a full range speaker is HUGE size to really get the bass right. I just don't think you can really do it with out a powered sub. The HUGE power in a sub tends to also tell you something! You just can't keep up with even a Boulder 1060 running C4's down low compared to powered subs(s).

The C4's are almost 6 dB down from reference below 30 Hz, that's HUGE power time (over double the watts) to get it flat. The C4's go that low with no doubling, but they are red faced trying to be FLAT and dynamic that low.
IME, the answer is a little involved:

The Velodyne DD series subs have (DRC) software that is effective (when set up manually, the auto mode sucks) in smoothing bass response by correcting room induced effects. If you are listening to music only, "not that loud", then one 12" DD will probably be all that you need. Two will almost certainly be more than sufficient for that application in that room.

The JL has rudimentary software and SVS sells a separate (SVS-Audyssey) DRC box that is purportedly terrific. The same solution can be provided by any pre-pro equipped with Audyssey (or similar, like Anthem's ARC). HK also includes a variation in their HK990 integrated amp.

The caveat:

AFAIK, DRC is always managed in the digital domain. That means that your analog audio signal will see "ADC - room processing - DAC". I know that this does not appeal to many 'philes, particularly those using vinyl. In my book, the benefits of the software are worth the multi-conversion trade-off, but....

If you forego DRC, then 2 subs (if properly located) will provide smoother response than a single sub. You can place them so that room effects on one sub are (more or less) balanced out by room effects on the other. An extreme variation on this theme comes from A 'goner Duke at Audiokinesis, who sells a four sub solution called the Swarm. I haven't heard it, but, for a non- software corrected subwoofer system, it's the most conceptually appealing approach that I know of.

Marty

BTW You might also check out Ryhtmik. I use a pair of their 12" subs (w/ Audyssey) in my 2.2 channel, music only system and get great results.
I use a single JL Audio Fathom f113 (no external cross-over required) and it's the best I've had or heard. I came from 2 REL Stentors and the bass is now more defined and tighter.

(Dealer disclaimer - not for JL though)
Rower30,

Try running your C4s full range with 1 or 2 subs running only up to 40 or 60 Hz. You should not need an external crossover. Try this and find the point where the sub(s)
blend well.
I'm running my Avalon Avatars with 1 James EMB-1200 like this, right now.
I have a Rel with my B&Ws and love what It can do. My low end is deep & smooth and the sound stage and imagining is great. The best think I did was put a Rel in my system. I would love to see what two of them would sound like.
Two of any of these subs is probably better than one of any of the others. The SVS seems to be in the sweet spot for you $-wise, so that is the route i would recommend for you. They are all very decent subs, once setup. BTW, the JL does not require an outboard crossover.