A Note For LS50 Owners

I have an original pair from 2012. For no particular reason—other than the fact I’m always looking for a good tweak—it occurred to me to check the four bolts on the back that hold the boxes together. 

Sure enough, overly loud listening over the past decade had loosened them. Without applying too much torque, I generally got at least a half turn with an Allen key, sometimes a full turn. 

And the sound? I was blown away by the change. It was black and white, night and day, stop and go. 

Well, not quite. But it was there. A little crisper, a bit cleaner on the transients. I think the speakers played a touch louder at the same power output. Certainly worth the price of admission.  


I don’t own the LS50, though I have heard them and have high regard for them at their price points. I’m only writing to share my appreciation for your post and sharing your findings. Many people come across these types of learnings and don’t share them beyond themselves. Thank you for being a valuable part of the community. 

Anyone replaced the driver on a LS50 from 2012. I have a tear on the outer membrane of the driver. If it is possible to replace the driver, what is the degree of difficulty? The speaker still sounds good, though it must be sub-optimal now with the tear.

I have upgraded to the LS50 Meta this week but would like to have the old LS50 fixed up.

[Edit:] I just discovered this thing called GOOGLE.

Procedure to change driver on KEF LS50 - General Hi-Fi Discussion - StereoNET International


@yyzsantabarbara I have had to make a couple of repairs to my scanspeak drivers.  After the repairs the drivers sound perfect.

This glue is fantastic for gluing surrounds to basket, cone to the surrounds, or just repairing rips in the cone material. Anything speaker.

Speaker Grill Cloth Repair Adhesive, MI-3035. $13 on amazon.

You sound like you want to replace the driver to be able to say they are "perfect".  Make sure the new driver is an exact replacement for the old, sometimes they change drivers subtly, been there made that mistake.

@jetter thanks for the info. I am not going to sell the LS50, I will give it to my nephew in Canada. He is starting university after this final year. I am looking to pair it with the Cambridge Audio Evo 150. A very good starter system for him.


Monitor Audio has seen the value of this for years using one bolt in back to tighten them down.

Tip: Bolts or screws could be tightened with drops of nail polish on the heads so they stay on place firmly. Nail polish unlike glue, easily breakable when you need to unscrew those screws and bolts if necessary.

Update: I was being careful when I made my first post, which I thought was the responsible thing to do. But after more listening, I think it’s only fair to be a little more confident in my assessment. The speakers sound great. A few moments with a hex wrench made a noticeable difference. If you have LS50s with a few years on them, do yourself a favor and check the bolts. Good things may be in store.

I just switched out my LS50s for some Totem Model One Signatures.  Yeah, I know, Model Ones are old, but I found these in MINT from a dealer hear on audiogon.  But, perhaps I was slowly becoming disenchanted with the LS50s due to loose screws (both literally and figuratively)!!  All kidding aside, the Totems are on a completely different level of transparency and sound staging and timbre(tone).  Instruments just sound more real and uniquely different from each other and delineated in space.  Switching back to the LS50s, everything kind of sounds the same, like they're coming from speakers and not real.  Also, they LS50s sound way more bloated in the mid bass, muddying everything up in comparison.  Just different level, guys.  

I checked mine and sure enough a couple of the bolts needed a full turn. I was careful not to tighten them too much, I wonder if KEF has a torque spec for them. I can’t say I noticed a big change, but definitely something to keep an eye on with these speakers.