[Nuance]

I am curious to know how many have strayed away from the age old "2-channel purism" guidance and are now crossing over to a subwoofer(s) in their music system.  For those who are not integrating subwoofers, how do you control room interactions below the Schroeder Frequency, specifically below 100Hz, and how do you tame the ringing?  I have found it extremely difficult and very impractical to achieve a flat in-room bass response and reduce ringing below 100Hz without either utilizing acoustic panels several feet thick or some sort of PEQ device. 

The 2-channel purist point of view has been preached to us for decades, but surely I am not alone in thinking it is extremely difficult to achieve great sound without applying some sort of bass EQ...?  Some may say its a complete waste of full range tower speakers, so I am interested in knowing what steps they took to achieve a great sounding system (excluding having a custom room built, which is the best route to go but not possible for many people).  I'd also love to see in-room measurements of said systems showing that the steps taken actually reduced bass peaks and ringing.  Of course, this only applies to passive crossover designed speakers. 

[TheChairGuy]

I use a small, acoustic suspension sub to integrate with my small tower (ported) Linaeum's.

It sounds good (with judicious use of output control) and well integrated - when backed out far enough from the wall to avoid undue bass reinforcement.

The sub is the Gallo TR-1...a real corker.  The first of three subwoofers owned that integrates wonderfully.  Each of the three were smaller in size and this is the first acoustic suspension one.

I'm not trying for 30Hz and lower subterranean bass....merely bass reinforcement from 35-55Hz where the towers grow lean in output. There's not a lot of difference in much of the music with it in and out (are little to nothing at all noted when playing vinyl), it's just there to energize the room a bit more on some digital tunes (Herbie Hancock's 'Watermelon Man' sounds all the better with it on )

John

[Wayner]

Well, until a few years ago, there were not many sub-woofers until the multi-media surround stuff came around. The sub-woofer was needed to produce "cinematic" type of sound to accompany the movie. Almost every subwoofer's response is a big bell curve at best, so there isn't really a "wide-range" sub, at least to my knowledge.

I generally think that there is no need for a sub in a quality 2 channel system. If someone feels the need, I might suggest that something is wrong, or you are a bass freak. Room acoustics, speaker placement, amplifier, room furnishings and so on all have an impact on bass response, so these things should be considered before going the 2.1 route, IMHO.

Wayner 

[chadh]

I'm not sure I'm the kind of person to whom your question is directed, but I'll respond anyway since my current audio experiment uses subwoofers in my 2 channel system.

I've been running a single driver system for some time:  4.5" drivers, powered by 5w/channel of SET amplification.  I always loved so much about the sound, but wanted more body to the presentation (at least in some forms of music), and also wanted to free the little drivers from the burden of playing the lower octaves.

My solution was to integrate an active crossover into the system, feeding frequencies above 100Hz to the main drivers and the sub-100 Hz frequencies to a swarm of Audiokinesis subwoofers.  I'm happier now - although, the experiment has me eyeing new improvements too.  I'm worried that the rest of the system now needs to "catch up" to the performance in the bass registers.

I haven't taken any measurements, and I don't have any EQ control (unless I take care of it digitally at my source - a PC).  My crossover simply gives me 24dB/octave slopes on both high and low pass filters.  But I don't get any noticeable ringing.  Perhaps that's due to the distributed subwooferage that the swarm provides.

Chad

[mcgsxr]

I am in trouble for sure, as I cross over to 2 subs...!

I run a 2.2 system, all OB, biamped, for 2 channel.

Loving it, but I am for sure in the bass head camp...

[Wayner]

Don't you guys think it's more room size dependent? I have a sub in my 4.1 system out in the big room, but it's a big room (with the MartinLogan reQuests) and blends very well there. I also like the sub because it faces downward, which I think helps to  mask it's location, even better.

Wayner

[timind]

It took a few subs to find one which integrates well for music only. Or maybe it was all the room tweaking. Anyway, through trial and error I feel I have found the right settings and placement.
The sub is out on the same plane as the speakers and sitting on a 3 inch thick maple block. This got rid of the one note boominess and allowed the sub to play musical notes. Sometimes the sub is just adding room ambiance that would be missing without it. Although my main speakers do pretty well without the sub, the added realism is worth the effort.

[Nick77]

I wish my mains were flat to 20hz and i wouldnt feel the need to supplement. Also seems to be a challange hooking up a sub in 2 channel system. I think most mains only go to the fourties and a sub really fills in the low end. I think next time i upgrade speaks i will be looking for a all in one solution.

[jaxwired]

Don't need to.  I have Dynaudios.  Problem solved.  People listen to my Contour S1.4s and they go around the room looking under stuff for the sub.  So many lean balanced speakers on the market now days.  It can be really frustrating.

I don't like subs for 2 channel music because 100% of the systems I've heard the sub reduced sound quality rather than the reverse.  Of course I'm willing to admit it's possible to succeed with a 2 channel sub, but I've never heard it.  Frankly, I'd rather have clean sound down to 50hz and live without the deep bass. 

[gitarretyp]

In this area, I blaspheme most happily and follow something along the lines of the Geddes solution. My mains are run full range, and I have two subs, run in mono, placed pseudo-randomly in the room, with different and higher than normal crossovers chosen pseudo-randomly.

[bunnyma357]

I have a small room and actually have 5 small subs (3 Subs + 2 Powered Woofers in the tower speakers), and also have room treatments plus PEQ and am happy with the sound. I ran without the subs at first and the issue was too much fat boomy bass due to room modes. In doing research I decided that the Geddes idea of multiple subs made the most sense to smooth out bass response. Also with multiple subs volume on each is low, so it lowers the overall distortion.

When I started my system I was planning on a minimal 2 Ch. setup, but it just didn't sound good in my room.


Jim C

[drphoto]

I never liked the 2.1 setup. I could always hear the sub. Forget that "It's all omnidirectional at low frequency" stuff. I am convinced a single sub will be hard to integrate in most situations. (yes, I'm sure it works for some)

I'm now a convert to the multiple sub concept. It's not about stereo, it's about smoothing room nodes and integration.

I've got a pair of Rythmik/GR OB servos (2 drivers per side, so 4 total) and and old Mirage. It doesn't actually go that low, it doesn't shake the house, but there is no boom, no bloat, and you can not tell there are any subs playing. The bottom end is so clean now, I can clearly hear the bass guitar lines separated from the drums.

I know I sound like an evangelist, but I think there are several of us now. Some have even said that 3 dirt cheap subs are better than one expensive one.

I'm doing something nutty and running OB subs w/ sealed monitors. I thought that the OB design might have been why this worked so well, but now I think it's just because I have multiple sources. I don't think the design itself matters that much. Maybe the cool thing about the OB subs, is they don't require a big, heavy and expensive cabinet. Great for DIY on a budget. I do like the servo control. I think it's part of why these are so tight.

Just another opinion, of course.

[mort]

It is not feasable in some rooms to have floor standing loud speakers. In this situation a 2.1 system is perfectly viable (2.2) would be preferable but not always practical. There is no reason why a properly applied crossover to a removed driver suppling lower frequencys has to be any dirrerent than that of a contigues driver. Diffrent placement options will help, along with a thoughtfull and edjucated set up that is nessesary for premium sound in any stereo system. Additinal benifits come (as mentiond above) form not having your mains driver be required to supply the larger amounts of power required by subwoofers. This not only protects the satelights from clipping but also alows them to enjoy greater power reserves for transients. Many of todays satelight systems come with a built in crossover in the powerd sub that is specificaly desined to work with bookshelf monitors, in this application other than placement mistakes there shall be no diference than a full rang cabinet.

[kingdeezie]

I use a pair of GR Research Line Sources (+/- 3 20-20), so I really don't need a subwoofer for music; and I much prefer it that way.

I agree a lot of what other people have stated here; trying to get a subwoofer mixed into a 2-channel set-up is quite difficult, and unless you go the multiples route, its hard to even out the response.

I know not every room can accommodate floorstanders, but I have heard quite a number of bookself speakers, paired with the right electronics, and placed properly, that presented a nice bass presentation.

Obviously there are limitations, but if a sacrifice between tight and articulate bass, and more copious bass must be made; I would have to choose the former.

The LSs seem to give me very close to the best of both worlds; but given the need to make a choice, I definitely love great bass detail.

YMMV.

[pardales]

I have a system based around the Horn Shoppe Model 1's, and have Ed's CUBE (sub) which rounds the system out nicely. Blasphemy.....not.

[mjosef]

if a sacrifice between tight and articulate bass, and more copious bass must be made; I would have to choose the former.

What if...you can have both? 

I used to run a mini-monitor/sub system back in the day ('85-'95), with Whafedale Diamonds and a VMPS Original sub. Electronically crossed over with a Marchand XM-1 crossover @ 70Hz.(summed to the single woofer). It worked pretty well IMO.
The ideal as I see it, would be dual subs, one per channel. If I had a lot of space, that's where I'd go. My current speaks goes down to the low to mid 30's(Hz.), so I am content with the low extension, and am always tweaking to improve the articulation/definition of that low octave.
I didn't see it as "blasphemy" back then, or even now.
YVWV

[Quiet Earth]

I'm open to trying a sub again. I've owned three or four different subs off and on over twenty years or so, and always ended up giving up on them. Still, part of me would like to try again.

Not sure I understand how multiple subs will make ringing or room modes go away. The modes are still there, you're just fooling them by moving the speakers around. Won't you just find other modes? Or other integration problems? Why not move yourself?

I'll gladly take the the free lunch if they're handing 'em out.

[Quiet Earth]

Oh yeah, source material too. I find that quite often I would like a generous helping of deep rich air moving bass in certain recordings. Maybe a sub would do it? No. Maybe there's no deep rich bass in that recording.

Sure enough, plenty of other recordings I own shake the house. I would be endlessly turning the sub down, then turning it back up every time I switched records.

Oh yeah,,,,,,,,, that's one big reason why I gave up on them.

[Duke]

Not sure I understand how multiple subs will make ringing or room modes go away. The modes are still there, you're just fooling them by moving the speakers around. Won't you just find other modes? Or other integration problems? Why not move yourself?

Very reasonable question.

You cannot smoothe the in-room bass by repositioning a single sub, or by changing your listening position.  The best you can do is render the in-room peak and dip pattern less objectionable by re-arranging it.  However, herein lies the key to why scattered multisubs works well:

You see, each scattered sub will produce a unique peak-and-dip pattern at the listening position, any listening position.  The sum of these dissimilar peak-and-dip patterns is much smoother than any one of them would have been - audibly, significantly smoother. 

So to answer your question, the room modes are still there but they are being driven differently by each of the multiple subs.  In fact, the in-room bass soundfield of a good multisub setup in some ways approximates the in-room bass soundfield of a much larger room, with the more numerous and smaller peaks and dips approximating the effect of greater modal density (which is why bass generally sounds so nice in a good big room).

Why not just use a single sub and equalize?  That can work well for a single location, but the room-induce peak-and-dip pattern will be totally different in other locations, and in those locations the equalization is probably actually making things worse.  So EQ has serious spatial limitations.  And even for a single "sweet spot" location, there is anecdotal evidence that an unequalized multisub system sounds more natural than a single equalized ubersub.

As far as the details of what types of subs and how to integrate them, different multisub advocates have different approaches.  You can ask in my forum and I'll tell you what I do.

Duke

[drphoto]

Quietearth. the multi sub thing really works. I prefer my 2 OB subs w/ the crappy Mirage chugging along in in  the backround. It doesn't present it's own sonic signature, it just helps smooth out the room.

I swear this is not a crazy idea.

I can nickpick my system all day, but not on the bass performance.