Celestion SL6s restoration: Part I
Celestion SL6s restoration: Part II
Celestion SL6s restoration: Part III
Some years ago I purchased a pair of Celestion SL6s for €80,- I have listened to them on and off over the last few years, and, although I liked them, the wow factor was mostly absent.
Technically they are in good condition, the same cannot be said for the cabinets.
So I decided to try to repair some of the damage done to the cabinets. I also wanted to mount the crossover outside the cabinet, and create the option of bi-amping or use of an active crossover. Currently it looks like this:
I still have to find a good solution for the lower part of the front.
Another project relating to the Sl6s speakers that I am working on is a dipole subwoofer. The first iteration of that subwoofer uses a single Redcatt 15 inch driver mounted in a 44cm wide frame.
Crossover is active, at 120Hz / 24dB/oct.
Stands
The Celestion SL6s is a bit of a weird speaker in the sense that the optimal listening height of the speaker is not the usual tweeter axis on ear height. Celestion recommended a stand height of 18” (45 cm). That means that from a normal listening distance you can just see the top of the speakers, and ear height is actually slightly above the speaker. The subs have a height of 46 cm, and for normal use I build myself a pair of low stands (Height 45cm/18 inch).
The Tweeters
As can be seen in the pictures the tweeter is in integral part of the frontplate, the dome is actually attached to the back of the frontplate. The magnet can be removed, but you have to be very carefull while doing that. It is easy to damage the voice coil. Likewise I did not try to remove the wiring, because that too seems to me quite risky.
The airtight mounting of the tweeter is done with a putty like sticky substance around the mounting hole between the cabinet front and the metal frontplate of the tweeter. You have to take care when you assemble the tweeter to spread the stuff evenly, to create an airtight fit.
The bolts are corroded, but they are easy to replace.
Dome and magnet separated
The woofers (Celestion T3507 165mm (6.5″) PVC Diaphragm)
The woofer is a well build 6,5” model, designated T…
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Well done! Another piece of hi-fi loudspeaker history rescued from the breakers yard!
I have a copy of the 1886/87 Hi-Fi Choice buying guide which states that the "SL6S rates as one of the very best compact speakers and carries a clear recommendation".
The 6.5" Kobex-coned mid/bass driver has a unique two-part surround that is effectively a mechanical crossover. The inner half sufficiently reduces traveling waves in the cone while the softer outer half gives a freer suspension at low frequencies for "improved bass articulation and 'speed'".
It is also noted that the 40 cm, L series, twin-pillar stands are recommended for the preferred free-space location.
I have a copy of the 1886/87 Hi-Fi Choice buying guide which states that the "SL6S rates as one of the very best compact speakers and carries a clear recommendation".
The 6.5" Kobex-coned mid/bass driver has a unique two-part surround that is effectively a mechanical crossover. The inner half sufficiently reduces traveling waves in the cone while the softer outer half gives a freer suspension at low frequencies for "improved bass articulation and 'speed'".
It is also noted that the 40 cm, L series, twin-pillar stands are recommended for the preferred free-space location.
I bought a pair of the original SL6's with the copper dome tweeter when they were all the rage. They were certainly a fine performer but the originals were only around 82dB/W sensitivity. One of the tweeters went OC on mine and was fixed under warranty
Also have a pair of the later SL100's lurking somewhere.
Also have a pair of the later SL100's lurking somewhere.