LS-50 Speakers (Passive)

As a Kef dealer agree with Helomech and Tom6897, we are also an Elac dealer, The Unifi do not have the resoloution of the KEFs, and are voiced to be a bit on the warm side. 

The Kef LS 50 are cleaner, with much  more sound stage focus. 

We just took on the Quad Line the S2 monitor at $1,000.00 a pair are scary good, and in some ways out performs the LS 50 while having much better low bass, and even greater treble clarity and a very wide soundstage. 

Please PM us if we can be of further assistance.

Dave and Troy
Audio Doctor NJ

Unfortunately, the quads have been on the market for 3 years now on no one cared for them in europe.

I own the LS50s for two years and it’s a very well balanced speaker. You won’t be able to hear anything bulging or missing unusually or unnaturally. Very well behaved speaker, I won’t repeat other users’ findings about soundstage coherence and imaging. Its hallmark is the midrange, but bass is quite satisfactory depending on the room size and placement. The highs are nice too, but I’ve heard more refined or maybe artificially more elevated twitters that add a sense of airiness, but at the account of being forward. LS50 is quite in the middle, neither forward not laid back. Pianos sound very natural on LS50 and that was my starting requirement.
Take my highs impression with a grain of salt as I’m using the LS50s with an amp of my make that is based on old school of high gain high feedback AB class.
KEFs so transparent, that I easily hear a difference when I roll opamps in my amp. Switching the amp altogether with my old Marantz is easily heard by anybody, not just by attentive ears.

On the negative sides, this is a tricky speaker to position and mate with the sub(s). It has a very strange bass dispersion pattern, where lateral or generally off-axis bass propagation is in my opinion quite stronger, so you end up with a very clean and lean bass in the listening plane and tons of bass in certain areas of the room, well off-axis. For my taste, I’m lacking the midbass hump for a better impression of size. Its lower bass, is actually quite heavy and gives nice slam impression.
Also, LS50 do have the tendency to sound better on higher volume.

With the end net sound being very dependent on the amp, I wanted to shortcut the amp matching game, sell them and buy the new wireless version, which I listened positively  at "High-end" in Munich last year.
I had a chance to hear a pair of out of the box LS50w last week and they completely put me off of my previous decision. They were nowhere near the mids and highs perfomance of the passives. I guess they really need a long break-in period to start working, but I didn’t want to risk with that.

So, to sum up, if you have a small to medium size room, you will be hard pressed to find anything to complain about the LS50. In larger rooms, the midbass energy drops quite a bit and you will need a solution for that. I haven’t found it yet because it’s not the low bass or sub bass that is missing but the midbass. My sub helps add weight but not in the upper bass and I cross the sub quite high at about 100Hz. Then again, the placement of my LS50s and the sub is far from ideal.
Maybe someone will help with an idea of a sub or bass that covers not only the sub range and has a very good managment of the bass.

^There’s a good chance your LS50s are placed on a room mode. If your speakers are somewhere between 2 and 3 feet from the forward wall, this is likely the case. These distances typically result in an upper bass null. It’s unfortunate because that distance allows decent soundstaging while remaining aesthetically acceptible. You might try moving the speakers to less than 20" from the forward wall (of course this will cause imaging to suffer) or try moving them 5 to 6 feet from the wall (measured to the centerline of the speaker cabinet).

I just don’t get why anyone would buy a speaker with a 6.5” woofer in a <1 cu.ft. box and expect it to move the earth. Nor do I understand why you would then try to marry it to one or more subwoofers and expect no ill effects on the sound quality. If you’re after full range sound, buy a full range speaker with a big woofer in a big box. There’s a reason that there were very few subwoofers before the advent of “home theater”. That’s where they belong.