A Sub Woofer for KEF LS 50's

I would like to know if KEF LS 50 owners are using a sub woofer in their setups and if so, what brand/model are you using and at what crossover frequency ?

 

I auditioned a pair of these, and honestly think you will have a hard time improving them with a sub. They are great, but designed for a specific purpose. Adding a sub is likely to muddy their imaging. It's like putting a V8 in an MGA - it works against the intention and strengths of the original. Just my humble opinion.

 

Hi gingerly thank you for your opinion it is greatly appreciated. When I purchased my pair the audio guys at the store mentioned that they had unsuccessfully attempted to match a sub and felt they were better on their own. I am happy with the bass response (which I consider to be more than adequate), however, I noticed in another thread on the KEF LS 50's that some owners were using a sub which I found interesting. I suppose I am just toying with the idea.

 

You can always just move them a tad closer to your back wall and/or corners. I first auditioned them at the dealer and they had them about 5 feet from both, and it wasn't happening for me - I felt I wasn't giving them a fair shake. I moved them straight back about a 1 - 2 feet, and the bass integration snapped into focus. They sounded a little lost and diffuse to me before. Since you've already got 'em, move them around and see what you get... but mark your previous positions carefully, of course.

 

Mine a just over 2 feet away from a heavily curtained rear wall and away from corners - I do not have a dedicated listening room and therefore lack some flexibility in moving the speakers. As I said I do not feel they are lacking in bass response. The fact that some owners are using a sub piqued my interest.

 

Get the LS50's.

Get a $500 sub from SVS direct. If you don't like it you can send it back, I think it's 30 days. Maybe even 60.

 

Try one of these.

http://sumikoaudio.net/rel/idx_products.htm

 

Use em nearfield, no sub

 

I just heard these today and to be honest I wouldn't even bother adding a sub. The bass was not real deep but what was there was astounding for a tiny monitor good enough on it's own for me. Overall these are great speakers for a small room, I was really impressed with the soundstage and imaging.

 

Thanks guys for your impressions and suggestions which are greatly appreciated.

 

Using a pair of 8" Audio Engine subs with excellent result.... The only way it muddies the imaging is if you have the subs crossed over too high. Got mine set at about 70hz.

 

Thanks TONEPUB for sharing your thoughts.

 

I have a velodyne dd15 conectedbto my kef ls50 .
The sub cut at 80 hz the signal to the kef so that the small cones can work free from distortion and reprosuce midrange frequency even clearer.
The sub is integrated with the loudspeakers thanks to the auto eq system that takes also into account the room acoustic.
The sound with the sub is almost perfect and much better than my previuos bw 800

 

Right now I've got a Dayton SUB-800 crossed over at 80Hz and my in-room response is now +/-2dB down below 40Hz. Prior to that it was a steep roll-off below 80Hz. I run the LS50s full range and have not found the sub to muddy things up at all.

Bill

 

In my experience this muddies things up more than adding a subwoofer, especially from a imaging and soundstage perspective.

Bill

 

With every speaker there is a compromise, when moved around the room. Every speaker has it's own balance. A speaker in the ideal position will not over-emphasize or muddy the bass OR make it thin, or the imaging diffuse. The listener will be the judge of the perfect balance.

In MY experience, it's much easier (and more important) to work on speaker placement, than to fiddle with a sub-woofer trying to get an accurate tonal balance that doesn't have "one-note" bass because of a predominant resonant frequency in the listening room. Why create another variable? My advice is always to buy a quality speaker with a fairly flat frequency response in the frequency range you want to listen in, and if you want to tinker, correct your ROOM instead. Save the boom for your home theater, or:



This constitutes my 2¢.

 

This is EXACTLY what I did and the LS50s are anemic, in my treated room, when properly placed, below 80Hz. The sub has only added to the enjoyment and not taken away. The idea that they're only for home theaters is a sad misnomer. You don't know what you're missing. Best placement for bass is always, ALWAYS different than best placement for everything else. What you are suggesting is a compromise and one that I am not willing to make.

Bill

 

We shall have to disagree. If you are still having issues with bass in your room then I would have to believe that either those speakers are a poor match for your tastes, listening room (is it particularly large?), or that your room treatments aren't properly implemented. This is where home auditioning is recommended. Moving the LS50's during my audition did not noticeably injure any aspect of their performance, and in fact ameliorated what to me sounded like anemic bass response, though admittedly I didn't do a freq sweep with my db meter in hand to check the accuracy of this assumption.

I'll say upfront that I don't think that subwoofers are only for home theater, though I DO have one for mine. What I DO think is that speaker designers are clever chaps, and spend a lot of money and time designing a variety of speakers for different purposes. When a subwoofer is important to a configuration (especially one where a decent amount of bank is being spent), it's usually part of the integrated system. Alternately, many speaker systems are designed to produce frequencies correctly to much lower levels.

The LS50's are a very well-designed product, harkening back to the classic BBC LS3/5A monitor heritage, and looking toward the future as well. Indeed, they were intended to represent KEF in it's celebration of 50 years in the business. They are intended to project a balanced, tonally accurate response within prescribed limits. I think they do a fine job at just this. Stereophile's measurements suggest they do too, being fairly flat down to 50hz.



I wonder if this is the crux of the issue for you, that these speakers only output bass usefully down to about 50hz. If so, I personally would have first recommended you audition a speaker with a tonal balance that suits you. As it stands, I'm happy you have found a setup that pleases you.

 

This sub integrates well with my Kef's.

http://sumikoaudio.net/rel/prod_b1.htm

 

I think almost any speaker would benefit from a subwoofer covering the very low bass.
This especially if the sub has an auto eq system taking account of room acoustic and if the speaker are cut at 70 or 80 hx.
The reasons are:
- only with auto eq you can compensate room reasonances
- Very few if no speaker repripiduce frequency below 30 hz
- Taking away from a the loudspeakers woofer the basses below 70 or 80 hz the same woofer, taht normally cover at least up to 300 hz, is free to reprosuce the human voices without interference and distortion

In other words not only the a sub with auto eq is the only way to reprosuce basses below 30 hz and at same tome limit the effects of the room acoustic, but also and in my opinion most importantly, it lets the speakers sing in midrange free from low frequency interference.

 

Hi Bill,
I auditioned a REL T5 sub-bass (as they call it) for over 2 hours yesterday with the KEF LS50's and the same integrated stereo amplifier that I have. The sub did not dominate or muddy the sound of the KEF's when appropriately set for volume and crossover. The sound is clean (not boomy) and warm. It was great to hear the difference with recordings where the bass extends below the 50Hz range of the KEF's. Probably getting down to 30Hz now.
I particularly like the idea of running the KEF's full range and using the sub to extend the range of the bass only. I have the sub connected to the A speakers on the amp and the KEF's to the B speakers. I can play the KEF's on their own or with the sub when I switch to A+B speakers on the amplifier.
I have plenty of time to experiment with placement, volume and crossover point on the sub now that I have purchased it.

 

Nice choice!

 

Hi Jeffey it is the baby of the range (8" driver), however, it shares the same beautiful clarity of sound that is a hallmark of the KEF's. They seem to be a very compatible combination.

 

The biggest driver is only 5.25 inches and you won't benefit from a sub or two? Don't believe it. Even an 8 inch driver will benefit from a powered sub or two. A sub would most certainly help these. Try an 12" SVS with a 400 watt sledge amp. It will make a good start at obtaining "real bass". I had LS3/5A's many years ago with a sub cabinet that had 4 x 11 inch woofers and 600 watts. Worked well.

 

I'm a fan of both brands, excellent products. Rel subs deliver the goods without ever sounding boomy. They integrate very well. Enjoy.