Hi everyone
About 12 months ago I helped a friend acquire a pair of M100's. They are the original mk1 version with overload protection but without the overload LED on the front. I have another friend who got a pair of m100-2 about 18 months ago and since then my other friend has always wanted a pair.
So the mk1 pair never sounded as good as the mk2 pair. The mk1 pair had issues mainly in the high frequencies, they sounded dull, you had to sit directly in front of a speaker to really hear them. Over time the mk1 pair sound seemed to degrade even further with a major loss of treble and the bass seeming to loose its punch. My friend who purchased the mk1 pair is a repair technician and despite me insisting that he have a look at the crossovers, he had resolved that the mk1 must have some difference which made it not sound as good as the mk2. His claim was that the caps couldn't be the issue as they haven't been under that much stress over the years.
After a few glasses of Scotch a few weeks ago and my blatant statement that his KEF 104's sounded way better than his M100's which quite frankly sounded 'crap' in their current state, we pulled the back off one speaker, popped some caps off the board and did some testing.
50uf caps reading anything between 80uf and 120uf
4uf caps reading 8uf
The list goes on, most caps 1.5 and double their resistance, not a single cap was remotely within the spec. So we ordered some nice poly caps for the HF circuit and some reasonable electros for the lf and got to recapping.
First reports from my friend are that the HF is back and very nice, midrange is great and lf is a little more reserved. I am yet to hear them but will be doing so this evening and will report back.
I have always been a fan of recapping speakers. My S45-2s which had silver (not gold) ROE caps I recapped with audiophile poly's and I really dont believe it made a huge difference.
I recapped my S75's with Martins kit and a generic poly 2.2uf to replace poly's which had been burnt by incorrect placement of the resistors on the assembly line. The difference in the S75's was immense with much more top end and major improvement in midrange and tightening of the bass.
I was, however, as was my friend (who is senior tech at 2 major radio stations) quite amazed at how totally off spec the caps in his M100's were. My friends observation was that the caps in his M100s.
Thought some of you might find this interesting :) Here is a pic of some rough on-board testing before we pulled the caps off, not the cap being tested is a bit of a different colour to the others, this was the same in the other cabinet.
Drew
