musical subwoofer recommendation for 2-ch

Can someone recommend good subwoofers for 2-ch listening? I recently purchased a pair of very articulate speakers made by JAS audio. They have small woofers and so they are fast but do not have sufficient low bass.

I have a 15" Velodyne SPL-1500R. It is very powerful. But it is too slow to match up these speakers. So I'll save it for HT applications.

I am thinking to get two 10" subwoofers and connect them to the speakers. Is this a good idea? What are the good subwoofers I should consider?

Thanks in advance.
Consider REL and Vanderstein subs. Very fast, very tight, very musical. Subwoofers are omnudirectional and so you probably only need one sub.
I have had experience with REL and JL Audio subwoofers. Both are highly regarded here on Audiogon. My REL Storm III subwoofer was connected to the high-level speaker outputs on my power amp, but could also be connected to the line-level outputs on my preamp. My current JL Audio Fathom F113 hooks only to line-level inputs. IMO the REL was easier to integrate with my Wilson WP7's, but was more limited in bass impact than the JL. The JL has a lot more adjustments but you would probably have to work harder to get it to integrate with your speakers. The JL has a lot more impact, especially on the low end, and you can actually hear the pitch of bass drums. In either case it was possible to integrate them so that I could not hear it separately, but only could tell it was on when I switched it off and then realized what it was adding to bass impact and spatial detail. IMO the lower the frequency you roll it off, the better subwoofers work, as they work best when adding what your main speakers are not capable of, or as in my case, I only use it to pressurize and de-pressurize my room. So if your main speakers roll off at 70 Hz, I don't think a sub will work well going up to 70 Hz. There are those who think a pair of subwoofers work better but I have never tried it.
What do you mean exactly by "slow"?
They have small woofers and so they are fast but do not have sufficient low bass.

Large woofers do not have to be slow. It boils down to motor voice coil diameter and magnet size and critical damped in design (basically this adds up to large size/cost)

Small woofers with small diameter but long voice coils get hot very quickly and you get thermal compression as well as distortion as they quickly exceed Xmax (linear operating range)...
All of the above. The REL is the easiest to setup and integrate.
I'm using a Martin Logan Dynamo with great success. It has 10" aluminum woofer that's very fast. About $600 or less. The next step up, the Abyss has a 12" woofer but is the same design. Both can be set up to fire down or out.
If I use just one sub, will it impact the channel separation and sound stage? My main speakers' specs claimed a -3dB point at 35Hz. Since the woofers are quite small (twin 6" per channel), I don't get the presence of low bass from them.

Which REL should I get?

By "slow", I mean the bass does not have texture. For example, you don't hear all the details in drum rolls.
Vett93, I am using a pair of MJAcoustics Ref200 with my Wilson Benesch Arcs and they are working out great. Fast, detailed, never muddy, manageable and a good blend with the speakers. The dual crossovers for the high and low inputs and a programable remote is a plus. Check out Jason Scott Distributing for info and give them a call.
Here's one you might try to find on the used market.

Click on link and scroll down to subwoofer review.
I would be careful about your assumption that you have a "slow" sub - unless it's a piece of crap (and yours certainly is not) there is really no such thing. Check out this article:

I think you have a sub integration issue that likely has nothing to do with your fine sub. Your comment about drum rolls reinforces this - I can't think of a drum roll that your sub would even produce or that you would want it to produce given your speakers. I guess it's possible if you have it crossed over at it's max upper frequency but even then I'm not sure.

I think you either have speakers that don't do what you want them to do with your kind of music at your listening levels and/or you don't have the sub integrated properly - the combination of placement, volume and crossover is wrong. I would investigate these things carefully before shelling out more cash on a sub that someone on a forum claims is "really fast" and likely will not fix your problem.
RBH 1010 is a fantastic sub IMO
I'll bet your Velodyne is fine. You just need a decent crossover to high-pass the small woofers in your JAS speakers, as well as, proper test tones and an SPL meter to match levels. Before you dismiss a perfectly good sub, pick up an NHT X2 filter (you'll need regardless of what sub you choose).

BTW, NHT is closing out their U1 and U2 subwoofers (check the subwoofer section here at audiogon) - both of which come with the crossover. A pair of either would be killer.
You should also consider the James EMB's. Musical and speed are their virtue.
Let me describe my system. I have a 2-ch system integrated with my HT system. The 2-ch system has ModWright Denon player, BAT preamp, and Counterpoint NP100 hybrid power amp. The HT system has B&K Surround Processor and a 7-ch power amp.

The Velodyne SPL-1500R is connected to the LFE jack of B&K Surround Processor. For HT application, I set the cross-over at 80Hz. At 80Hz, it is too slow and boomy for 2-ch application. I have to set it at 50Hz to get good bass.

Another point is that I don't want to use B&K for 2-ch music. It is a good machine. But the ModWright Denon player and BAT preamp are better.

This is why I am thinking to get another subwoofer for 2-ch music and connect it to the speakers directly. Then I'll set the cross-over at around 50Hz.

Hope I am making more sense now.
Once again the REL's have separate inputs for HT and 2 Channel with separate volume controls.

If you set the crossover point the same for both, you will never have to touch it again, and will not have to buy a separate subwoofer for both.

As a matter of fact if you can afford two subwoofers, you could get one REL that is twice as good as the two separates.
Itball's advise matches my very recent experience in setting up a sub with full range speakers in a 2 channel system.

My gut feeling from your description of the sound you have described is that you have set the volume of the sub too high and its output is masking the detail from your main speakers. A cross over setting of 50hz would seem better than 80hz but, I would suggest that you get a SPL meter and a test disc to assist you in both locating the best position for your sub and matching the output levels of the sub and mains. That worked well for me. It only took about 18 hours over four days and a lot of critical listening to dial in my sub (and I think I can still do better) so set up is not a plug and play matter. I wouldn't give up on your Velodyne not would I depend on its automatic set up/equalization system to get the best response.

Hope that helps a bit.
Thanks all who are the supporters for Velodyne. I really like it too. But it does not have separate inputs for HT and 2 channel music. With Velodyne, you can use either the line level input or high level input, but not both at the same time.

Additionally, I don't want the LFE signal from 5.1 to go to the L/R channel speakers. So I'll need one sub for the LFE.

Which REL should I get? My room is 15X25X9.5 and is open to the rest of the house.
The REL's all work basically the same way. That is a big room. So get the biggest you can afford.

Or.... if your budget can fit it, actually get two subwoofers; one for each stereo channel. If the subs are of very good quality, stereo subs are better than one, especially in a large room.

Setup is just as easy. You just run one stereo channel to each sub. For HT, you will need a splitter on the HT decoder if it only has one output.
Will smaller REL subs be more articulate than bigger ones?

Thanks for sharing. That article was very interesting. My experience has also been that mid range seems to affect bass perception enormously. It has always puzzled me how even a blown tweeter (far from bass frequencies) will modify bass perception. I guess heavy bass percussion is just all over the frequency map even if most of the energy comes from the woofer....which is why it is such a telling test for speakers.

As Mr Blackburn states it may boil down to subtle cues in phase. It may indeed explain why two ways with small woofers generally have a better reputation for fast bass...they have one less crossover to worry about! It is certainly consistent with the logic that a cheap two way is a safer bet than a cheap three way. (i.e. to go three way it is better to go significantly up in cost or the two way remains better value)

Interesting and thought provoking - thanks
No, smaller REL's will not be more articulate. REL's are not "boom boxes".

REL's particularly the Audiophile versions will be more refined the more you spend; no different than a higher end speaker is more refined. They are after all made to work with Audiophile speakers. An unrefined subwoofer would ruin the sound made by an otherwise refined system.
My Velodyne is getting much better after I use the high level inputs connected directly to the speakers and set the cross-over at its lowest value, 40Hz. This is the recommended approach of REL subs.

I noticed a higher distortion level when I played louder. I probably have reached the max output and the self protection circuit has kicked in.

Velodyne's website showed that SPL-1500R is too small for my house. The listening area is open to the rest of the house, which is about 8 times the size of the listening area. So I am thinking to get a 2nd subwoofer. My requirement wish list for this 2nd subwoofer has:

1. It should work well with SPL-1500R.
2. It should also be musical.
3. It should take both speaker-level and LFE inputs. Velodyne SPL-1500R can only take either one, but not both.
4. It should has separate gain controls for speaker-level and LEF inputs.
5. This is not a must. But ideally, it should have classical music and movie modes.

Which subwoofer will meet the above requirements?

My current sub is located along the long side wall. Should I put it at the corner to boost up the bass without clipping the amp or triggering the self protection circuitry?
What about the Kharma sub?Its fast as hell!!!


Although I haven't compared 2 subs at the same time, my rel strata III works well with my magnepan 1.6's, which isn't a easy feat. A sub that is to be mated with magnepans has to be as tight and fast like the maggies. The fact that the strata III is sealed and has many tone controls allows it to blend quite nicely. I do have a question though concerning my rel. Does anyone know if the power switch on the REL Strata III should flicker when on? On mine the toggle switch for the power button which lights up, also flickers. Could this be a connection problem or is this common? Thanks.
I use a Velodyne HGS-15 with a pair of biwired KEF 102/2s crossed at 80 Hz, and they seem to blend seamlessly.

I noticed a higher distortion level when I played louder. I probably have reached the max output and the self protection circuit has kicked in.

You are running your "small woofer" main speakers full range, so it's not surprising that you are hearing increased distortion at higher levels. This has nothing to do with your sub; it's most likely the small woofers. Since you're not biamping with the sub's amp, it may be possible that you've pushed your main amp too hard.

Both of these reasons are why high-passing the main speakers makes sense.
Please excuse me if I may ask a question and I don't mean to distract from Vett93's original post, but to the REL sub owners out there, "Does anyone know if the power switch on the REL Strata III should flicker when on? On mine the toggle switch for the power button which lights up, also flickers. Could this be a connection problem or is this common?" Thanks
Since you're not biamping with the sub's amp, it may be possible that you've pushed your main amp too hard.

That would be my guess too.
It turned out that I had set the subwoofer gain too high. Later on I used a Rives CD to generate tones and caliberated the gain and phase of the sub to match up the main speakers.

Thanks all who suggested that I should keep the Velodyne SPL-1500R. It is indeed a good sub.

Now I just need to get a sub for the HT processor for movies, which is much cheaper.
another vote for rel, these are very easy to integrated w/ most speakers. They are fast, articular and doesnt call attention to itself.
The mimic the character of your power amp. If your power amp is fast, the rel will be fast. If your amp is slow and muddy, bass will be the same.