Question for sub woofer users

I'm kicking around getting a sub for my Quad 2805 speakers.  Here's the question;

Are subs "set and forget," or do you have to constantly fiddle with output volume and crossover point with different recordings?

Thanks in advance,

Subs are the devil’s 3rd child. Properly integrated into the room and with your system a single sub can be magical. Poorly a real beast that will never work out well. The deeper the sub, the more bass extension you try to get the harder it is to do it right. So a smaller sub may in fact sound much better for you, depends.

Easiest if you can get an installer to integrate them. Acoustics, EQ and placement all matter. A pro can do it in 1/50th the time.

Next most easy is if you find a sub with a good sounding auto-EQ. I can’t hear the difference between super awesome 500 tonne subs and merely very good subs, but I CAN hear the difference in the EQ settings. So it’s very worthwhile asking other owners for their experiences. If you JUST do EQ it won’t be nearly as good as EQ plus room treatment.

Hardest is getting the room right, measuring, placing it yourself and creating your own EQ curves.

Equally difficult is getting 2 subs right.

Additional resources:



A bigger problem in using subs with the Quads (or any other planar) is getting them to sound "one" with the speakers. Dipole users complain that subs produce bass that doesn't integrate with their speakers, sounding detached, tacked on, and of a different character.

Dipole users have tried all kinds of subs with them, the Finnish company Gradient creating a dipole sub for use specifically with the model 63. A dipole sub is a great idea for use with dipole speakers, for the obvious reasons.

There is a VERY unique and excellent dipole sub available, but it requires a little bit of DIY. GR Research's Danny Richie and Rythmik Audio's Brian Ding combined their talents to create the world's only Servo-Feedback Open Baffle/Dipole subwoofer, and it's killer! Voted "Best Bass at The Show" at numerous RMAF's, details on it are viewable on both the company's websites. Highest sound quality subwoofer currently available, at any price, in the opinion of many who have actually heard it.

jzzmusician - In my experience they can be set and forget after the initial (week?) of set up.  I fairly recently got a pair of SVS SB1000.  Not the most expensive subs out there but they have greatly increased my level of musical enjoyment.  They seem to bring something a lot more complex than just "deeper bass".  While their contribution is significant, on another level it is "subtle" (for lack of a better word)....they are sort of figuratively "invisible".  Integration was not the nightmare some have experienced.  I suspect setting them up to round out the bottom end of full range floor standers (my use) would be easier than setting them up to work with limited range monitors.   I do have a complement of GIK room treatments including floor standing corner soffits on the wall behind the speakers/subs.

I set them up mainly by ear but also with some on-line tone samples and a Radio Shack SPL meter.  Maybe not the most sophisticated method but it gave me insights to necessary adjustments.  Gain, cross over and phase all continuously variable.  I don't find myself tweaking them constantly though I sure as heck can hear a lot more of the differences between recordings and even track to track. 

Not trying to contradict any of the good advice Erik is giving you.  Just reporting my experience.
My REL B3 took a week to get set up correctly and I've never touched it since (3 years) with the exception of connecting it to my new Accuphase. You would never know it's there besides the fact that it's big. I have to get on my hands and knees and put my ear next to it to know it's actually working. I couldn't live without it now.

No problems with a sub here . Set it and forget it . Glad i lucked out incorporating a sub i guess .
The main problem people have with subs is they turn them up to loud. You should just be able to tell that a sub is in the system. I have set up subs for many friends with all kinds of speakers and have always achieved excellent results. No problems with planars. I do everything by ear.
Volume too high and placement in corners or close to a wall . Then it will stand out like a sore thumb .

With my Quad 2905's I use two Rel B2 subs, started with one in the suggested corner position but realised eventually that two subs is the way to go.

The quads were positioned according the Nordost one thirds recommendation and subs using Cardas set up for full range dynamic speakers, this placed the subs slightly back and inside between the Quads.

Tonality and isolation was achieved with the Rels  raised and isolated on cast concrete boots, once dialed in the results are satisfying resolving and virtually indistinguishable although my tastes lean towards the cool side.

Phase coherence is only achieved with two subs , Jim Smith's book { Get Better Sound } and subwoofer setup at the Martin Logan website have usefull info on subwoofery.

Quads excel  in micro-dynamics and good subs improve the macro-dynamic aspect of these speakers. Once you hear your Quads with well integrated  subs then turn them off in the middle of track you'll think someone turned out the lights.

Erik's advise is very good, and Adhendler's  but I also found two subs easier to integrate and talk about the room, the best Bass in my room is with my back  hard up to the back wall only due to the longer wavelengths perceivable there so you see , subs can be a tin of worms but well worth  the effort in my opinion, and obviously there is a smorgasbord of subs out there.

I concur with the above. After a set up period, you should have things dialed in. As far as a sub for the quads, I would recommend a Vandersteen sub.
I have resisted having a sub until last year.  Consequently, i was never happy with bookshelves (limited bass output), and i have tried several floorstanders that were never perfect. So i decided to give a shot with the svs sb1000, and setup was easy.
  It is connected to the preamp output of my integrated,  with the filter on the sub set to 50hz, frequency at which my speakers start to cut off.  The output level on the sub was set using my ears and white noises at various frequencies to achieve even coverage down to 30 hz, maybe a little below. 
I am quite happy with the result, movies are more lifelike, and i now have been back to bookshelves as the bass output is almost what the vandy 2ce were putting out. Swapping bookshelves is much easier than floorstanders.
I would need a second sub for my setup to be perfect, for me at least.  But i think my wife would punish me.
I have no other experience with subs, but it made sense to me that a sealed sub would be much easier to setup.  That is one reason why I picked the svs.

Read in a book that a good place to set a subwoofer is as close to the listening position as possible . Have been using that method for a few years . Works well . You would think you would sense the sub being so close , but the bass seems like it is emulating from between the speakers . Pretty cool . 
Thank you all for sharing your experiences and advice.  I'm going to start watching the listings and if something good comes up at a price I can afford I'm gonna give it a shot.

Several of you felt that two subs were waaaaay better than one.  Others, not so much.  The phase issue with one sub was mentioned and that would seem to be pretty important. 

Should I be looking at two subs instead of one?  The available room is not a problem unless, as lustformusic felt, that the subs were best positioned inside the speakers.  This may be a problem for my wife as there is a television that would probably be in the way.

Thanks again, you guys are great!

Forgot to ask a question;

I've got a Prima Luna integrated that has one "mono out." 

Is is possible to hook up two subs with only one out?

Thank you again.

I’m in the 2 subs are better than 1 camp myself. A pair of Ohm MicroSubwoofer 10’s have been in my system now for a few years and have been integrated easily (by ear) with 3 different pairs of speakers (Maggie MMG, Mark & Daniel Ruby, and Ohm MicroWalsh Tall). For crossover duties I use an old Outlaw Audio ICBM -1.

@jzzmusician .. a y-splitter would do the trick.
Yes, two subs if you can, it will be more robust and spread out.  Even though we say that bass below  a certain frequency is not directional, you still feel where it comes from.
Pretty much set and forget.  There are variables in the engineering of recordings that will make them 'stand out' or 'recede', but that's kind of part and parcel of 'modern music', genre dependent...
Proper placement....'sizing' or 'scaling', taking into account what you're pairing it size....getting the crossover point 'right'...the usual variables we all know and deal with in any system...*G* 
Definitely get two subs.
One sub can be fine and you should simply move it around until you like the sound (generalizing, but my original REL worked great alone). I did get another REL last year and I like having two just to calm the corner standing waves. The "leave it alone" level thing doesn't work for me as bass levels on recordings can differ greatly, and I simply turn them up or down sometimes (rarely, but necessary)…no big deal as the level is right there. If you have a Room Correction Nanny gizmo you may be able to leave the sub level alone.

its mono out of the subwoofer output. Just get a y adapter to split it. 
If you know all the tricks you can set a sub up in a week and be close. If not, you could fiddle around for months and still not be entirely satisfied.

 Phase is particularly important if you want adequate output and a tight clean sound that has that dynamic punch. Many times if you are using a single sub it is best to use only one channel of the output. Particularly if you are crossing over at frequencies lower than 50hz. No real separation down there anyway.

Placement to avoid nulls is critical too. Once setup you move toward and away from the sub. You'll find spots where volume is low and spots where it is high. If low, you are in the trough, you want the listening to be at the peak.

Some of the EQs are quite good at damping the peaks commonly caused by subs in smaller rooms and can be very helpful as well. Avoid using the the sub crossover between your preamp and amp, this generally reduces the purity of the signal going to your main amp. I usually try to use one set of outputs from the preamp for the power amp and a second set, if you have them, to feed the sub. That way there is no interaction electrically.

For those of you with high level inputs on your subs, this is the ultimate way to setup a powered subwoofer, though few realize it.

Using a set of speakers cables from your amp to your subwoofers high level input is actually the most accurate method for interfacing your sub, main speakers, and amplifier. Your sub is now receiving the signal from your amp, so it takes on the characteristics of your amp. Dynamics, phase, all much more like what the main speakers are seeing. Much better blend, try it, you'll be pleasantly surprised. I mean how can it sound like the amp when it's being fed by the preamp? It takes no power from the amp, the high level input on the sub is very high impedance, so it is really isn't seeing a great deal more signal that it would be from the preamp. However, the amplified signal is more dynamic, more vivid, and as you might guess, suits the nature of a powered sub very nicely.
I'm a REL fan of course, but I do question their claim that the High Level input reproduces the sound of the amp. I certainly uses the signal of the amp but since it then goes through its own amp this claim seems like hype…understandable, but hype nonetheless, and with low frequencies likely not a big deal anyway as low frequencies generally rely on higher tones for aural specificity (!) and much of the overall tonal character unless the sub is very poorly designed.
One thing no one seems to mention but that I think is very important  is phasing the sub properly. has plenty of info on sub setup.
He is the tech support guy at JL Audio. They know a thing or two about subs.

One thing no one seems to mention but that I think is very important is phasing the sub properly. has plenty of info on sub setup.
He is the tech support guy at JL Audio. They know a thing or two about subs.

Great site!  Thanks!
Technically they are supposed to be set and forget. But I find they need tweaking depending on the program material. Nothing to do with the other equipment, just variables in the recordings.