I'm considering a subwoofer for a pair of KEF LS50 speakers.

I bought these speakers recently through the classified section here and am really impressed with them so far. While I don't feel they lack bass for their size, I sure wouldn't mind them going a tad lower.

Last night while listening to Tracy Chapman's debut album I noticed a bit of discontinuity in her vocals when in the sweet spot. Hard to describe, but it sounded a bit ragged. After fiddling with speaker position and toe-in, in particular, the sound gelled and Ms Chapman's vocals snapped in to perfect focus.

I feel I could live with these for a long time if there was just a bit more bass. This makes me think about getting a sub to compliment them. My room is a small square and the speakers are set in a diagonal configuration. I would like to get a small sub which will integrate easily with the KEFs.

So far, the top candidate is the SVS SB1000. This is a sealed sub with a 12 inch woofer and a 300 watt amp. Any one have any experience with this sub, or SVS products in general? Also, I'd be interested in any other small subs that work well with the LS50, and I know quite a few members have experience with the LS50.

SVS offers a 45 day trial with free easy return so I'm thinking, what's to lose?

 

I have used SVS 12" ported sub for a while. I still use it in my home theater setup. I would say it is decent. Not bad, but not great for music even in sealed mode.

However, integrating a sub in a small square room in not easy. I have problem integrating subwoofer in small square room due to limited placement options for my subs. I have tried 8", 10", and 12" subs and not fully satisfied as I can't really get good "punch".

Anyway, if you don't listen loud and have lots of freedom moving around the sub in your room to experiment, why not give it a try?

If you have the fund, try audition JL Audio dd10. It is very good in moderate volume, but can't play loud cleanly below 40 Hz due to high harmonic distortion.

 

I'm partial to subwoofers made by REL. I particularly like the speaker level approach they use, easiest to integrate in my humble opinion.

 

Years ago I had a REL sub and though it was great for the money. And it did seem fairly easy to integrate.

The last sub I owned was a Gallo MPS-150 which didn't seem to ad much to the low end. Here's a pic of my room as it is now. I'd have a lot of placement freedom as room is only for music.

 

I'm new on this site but not new to music listening. I have the LS50 speakers in a near field (10 feet) listening room. This 2 channel system has an Oppo 105 playing directly out an XLR cable to a Paradigm A21. So obviously the A21 provides more power than I can use, but the LS50's are still limited in bass extension. I use a REL T9 using the REL XLR PARALLEL system, running the speakers full range and just using the REL to augment the bass. Using this method has allowed really great integration between the sub and the LS50 speakers.

 

I say go for a sub, but only if the room is decently-sized (12X12 or bigger) Otherwise stick to the Kefs for bottom-end coherence.

 

Check out options from Rythmik and HSU Research.

Rythmik only makes direct servo-controlled subs with speaker level inputs and has a couple models designed to play into the upper (punchy) bass region.

 

How To- Perfect Subwoofer Integration

 

I read that thread earlier as I was searching to see if anyone asked my particular question. If I get a sub, I'll go back to it.

 

I would recommend Rythmik as well.

Rythmik Audio • Direct Servo subwoofer products

 

quoted for the type of sub for the LS50s, not just the "how to". if you are serious about seamless integration certain features are needed.

 

I have use subs before and the main reason I stopped was the incessant need I felt to adjust it. I'd think the set up was perfect and then, with a different album, it would sound crappy. Not sure "knowing" it was set up right would change that.

 

it does, it sounds right. i use the same jl sub now with my harbeths. a smooth response means no peaks in the response. peaks are what drive the need for adjustment. smooth even response means more musical because all of the bass notes sound equal and allows the sub to not call attention to itself. the only adjustment i rarely fiddle with is the level control, and no more than 1/16 of a turn!

 

If you look on AK, there are quite a few threads on distributed bass. I use this in the 8033SII config running 2 subs in mono.
DSPeaker-Anti-Mode 8033

 

I have two Rythmik F12SEs and with the help of Dirac there is no need to make any adjustments. On rare occasions the sub the level needs to be be increased due to surround mixes that have low LFE. But that's about it for any adjustments.

I had DSPeaker-Anti-Mode 8033 in my system a few years ago and it worked great.

 

the only way to integrate perfectly a sub is with measuring gear.
if you want the best integration possible, get a cheap mic and soundcard..

integrating a sub is like being a speaker designer, you need measuring gear

and also a sub with hilevel input

 

I love my LS50's but before you go out an buy a subwoofer ( of which I do not have nor need in my small room) look in the KEF manual and use the bass inserts the speakers came with. They are those foam inserts you place in the holes in the back of the speakers and adjust thier distance from the walls...

Just saying try what the manufacturer suggests before you go spending money you may not have to.

Steve

 

the foam thing block the ports and reduce the bass output.
I have the kef ls50, they need a sub imo

 

Other than checking for peaks and nulls, I suggest that OP also check for left and right balance.
I am too lazy to use mic and computer. What I do is to use a test tone CD, play back tones from 120 Hz to 20 Hz, and use my ears and body to check for balance. : )

 

I have this sub and I think it's great so long as you don't expect too much. The main advantages as I see it are its low cost, compact size, deep extension (flat to 25 Hz) and sealed design (not ported, the best design for music). It's not going to rattle the windows and cutlery (well maybe a little) and probably won't do HT well unless the room is small. It's not going to compete with $1000+ subs, but for what it is I think it offers a lot of value. FWIW I'm running the SB1000 with Harbeth P3ESR and listen to mostly jazz, in a room that's 14x15, so I am not driving the sub very hard.

 

From my experience, getting a sub in a small room is problematic due to the amplitude of the bass and setting one in a small square room is very problematic. However you may get lucky so feel free to dismiss the following recommendation: I feel that in your case you will be more rewarded by a good room calibration, by which I mean using REW with a calibrated microphone.

 

You cross your sub at 120, are aiming for it's higer harmonics, or want to aid the adjustment by determining how it interacts from the higher lows of your mains/room freq. response ?

 

For $1500 JL Audio makes a sub with a pre-out AND a main in. So you run your preamp into the sub, and then the sub feeds your power amp.

The thing is - the power amp is seeing the signal after the crossover, so it's (depending on where you set it) say '80 hz and above'.

So both your speaker and your amp don't have to reproduce the low bass. This is the best way to do this and makes a big difference in how the whole setup sounds.

 

Well, that's the first thing I've heard today that makes any sense (the words of Lt. Colonel Hal Moore after surviving a day in the Battle of Ia Drang in Vietnam in November, 1965)

 

The $500 SB1000 has this feature as well, but the crossover point is fixed at 80 Hz. I tried it out but found that I preferred the sound when running the P3ESR full range and bringing in the sub to augment at 75 Hz and below. The ls-50 will be different of course.