In message
David J Worden
wrote:
In message
Eiron wrote:
Robert wrote:
I too built a pair of KEFs [concertos] about thirty years ago and I
still use them. The kits contained the front panel with drive units
and crossover ready mounted and wired and you built the box to a
specification. There was a range of sizes you could build with the
larger one giving a slightly better bass reponse. In those days you
could avoid purchase tax by building the cabinet yourself. They cost
£30 I remember :-)
£30 in 1975? That would have been cheap even for one kit,
never mind a pair.
My experience is that it can be well worth building your own cabinets.
Read on only if you are interested!
In the sixties I built a pair of folded-horn cabinets from a design in
Wireless World 1956 (October, I think it was!). The drive units I put
in it were Decca-Kelly horn-loaded ribbons with acoustic lenses and
Decca-Kelly 12" bass units with a pair of supplied crossover units.
The drive units cost 63 GBP and, with the wood, screws and glue for the
cabinets, it came to a total of 75 GBP for the pair.
As recently as a few years ago, when I took them (very heavy!) to the
local hi-fi shop to audition CD players, they put them on a pair of
(very) expensive stands and connected them with (very) expensive cable.
They sounded pretty good there to me, better than at home, so at the end
of the session I asked the assistant what he thought of them, to which
he replied "you won't improve on the sound for under 2,000 pounds, but a
commercial equivalent would produce the same sound in smaller cabinets".
I had been considering treating myself to new commercial speakers but,
after hearing that, instead I bought some proper cable for them for
about 30 GBP (I had been using lighting flex) and a pair of the least
expensive Foundation stands for about 150 GBP (I had been using
something of my own that I had made in wood). I re-wired them
internally as well as externally with the new cable and set them up on
the new stands. I wasn't bothered about their size.
In simple terms they then sounded very much better at home than they had
before and the stereo width opened out dramatically. So after 30 or 40
years I was now 'hearing' them properly for the first time! I cannot
say whether the improvement was due to the cable or the stands, but I
suspect it was a bit of both.
My point is that I seem to have a good result for (originally) 75 pounds
which has served me well for all these years and which (for an extra
180 pounds) is now better than ever!
Congratulations if you have read this far!!
David
Since posting the above reply in January I have, on advice (see P.S.),
added mid-range units to my setup. The advice was that 40 years ago
my system was good but that these days you wouldn't make a 12" bass
unit do duty up to 2,500 Hz. The additional crossover is now at 400
Hz and the mid-range performance is now significantly better: it used
to 'shout' at you a bit as you turned up the volume, but now it is
very smooth and even the bass seems (subjectively) to be better too.
I placed additional small cabinets on top of the existing ones to
avoid chopping the original ones about. The additional work has cost
about 100 GBP, so I am still of the view that there are advantages to
be had by building your own cabinets; one possible reason being that a
manufacturer will try to minimise the materials used in the cabinet
construction to save on mass-production costs, whereas you can be
generous with the wood, screws, glue and damping materials for a
reasonable one-off cost.
I hope this may be of interest and/or help to someone.
David
P.S.
The advice to make this upgrade and assistance in designing
a suitable new crossover network came from Howard Dawson of
Howard Dawson Audio
http://hd-audio.orpheusweb.co.uk/ who
supplies, among other things, replacement ribbon assemblies
for the Decca-Kelly ribbon speakers referred to above. My
thanks go to him, of course.
--
David J Worden
Buying speakers vs. making speakers
Hybrid Mode
