Recapping KEF reference series 105


I am working on some old KEFs. The midbass is bad and I assume it’s the caps in the crossovers. They are old and I don’t know how to order the correct ones 

New to this and don’t know how to add a picture. 

glattaski

The 105's came in a variety of versions, one of which needed an external equalizer I believe.

Mine has 2 crossovers. One inside the mid and the other in the bass box. There’s another board for the knob which I wonder if I can disconnect.

Caution:

Recent Crossover Overhaul:

My friend has two identical sets of JSE Infinite Slope Model 2’s. They sounded the same to both of us in repeated comparisons.

OLD: he overhauled the crossovers of one pair, we compared last week.

Cassandra Wilson; Kate Wolf; Annie Lenox; Richard Burton, VOICES

unchanged pair: maintained the voices as I/we know them for many years

altered pair: ALL the voices were shifted slightly up, the voices slightly ’wrong’, Richard Burton and Cassandra Wilson, their voices are very revealing, I always take them to stores and to friends systems.

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Sooooo

Two adjustable crossovers, NICE BUT TRICKY:

Unless you know crossover parts have failed;

Before you mess with crossover parts (no matter how old they are):

I would get a sound level meter with tripod mount,

AND a test CD (not lp) with individual frequencies.

Tripod, seated position, seated ear height.

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You say midbass is bad: Find what you are getting now. Mess with your equalizers, see the effects via the meters, i.e. actual not apparent.

TRICKY: To adjust, you need to match the l and r individually to each other, AND, you need to equalize the room when both are playing.

I have level controls, simply volume of mid horn to woofer, then volume of tweeter horn to mid horn, back and forth, again/repeat.

btw, a meter will hear objectively, does not account for your preferences and or hearing, i.e. old dog needs to boost the highs a bit more than the meter shows.

 

glattaski

"Mine has 2 crossovers. One inside the mid and the other in the bass box. There’s another board for the knob which I wonder if I can disconnect."

I'm just guessing, in case you could 'fix/adjust' your speakers before upgrading parts.

Is it possible you do not have the KUBE 200?

this one is sold, but it shows what it looks like.

 

 

 

https://www.hifi-classic.net/review/kef-model-105-3-13.html

 

excerpt:

"Our test speakers were furnished with an active external equalizer, the KEF Kube 200, designed for use with the Model 105/3’s.

The Kube 200 should be installed in a low-level signal path such as a tape-recording loop or between a preamplifier and power amplifier. Pushbuttons on its panel can replace the tape-monitoring function (there are tape-in/out jacks on its rear apron) and bypass its equalizing circuits. It has separate low- and high-frequency control knobs, with center detents, and a small, separate power supply.

The Kube 200 is 6 inches wide, 8-1/2 inches deep, and 2-1/2 inches high. Price: KEF 105/3 speakers, $3,500 a pair; Kube 200 equalizer, $390."

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IF you proceed:

Normally, each part, capacitors/resistors has identifying marks, and you can get new parts with those values (i.e. +/- 10%, or 'better' i.e. tighter tolerances.

My friend bought a device to measure his crossover parts, found a few parts that were bad.

I can ask him which device he bought if you want.

 

Mine also have 2 crossovers and the one by the knob. That knob connects directly to the speaker connector so they add resistance. Very strange. Doesn’t make sense to me. 
how did you add a picture?