Keith G wrote:
"Don Pearce" wrote


Without being able to trace the circuits I can't say for definite, but
that looks like a second order crossover. Are those chokes wound on
ferrite? If they are, this crossover has a power limit set by the
magnetic saturation of the ferrite. Your other one is a better way of
making a crossover choke.


OK, here's a pic of both sides of that crossover:

No, here's a couple of pix showing each side of that crossover:

http://www.apah69.dsl.pipex.com/show/topside.JPG

http://www.apah69.dsl.pipex.com/show/underside.JPG


The game plan is as follows:

Dr Rob very kindly gave me these speakers

http://www.apah69.dsl.pipex.com/show/donor.JPG

which sound fine but are easily beat by most (all, actually) of the other
spreakers I have here, due to a lack of any bass at all. I want to pull the
drivers (T27s and H3310s) out of 'em and use them in these boxes:

http://www.apah69.dsl.pipex.com/show/boxes.JPG

as they are a little larger and have easy, front access - see the original
drivers on a nice, easily removed front baffle he

http://www.apah69.dsl.pipex.com/show/originals.JPG


(Rob - speak now if you would rather have these back instead of me
cannabalising them!)


Go for it Keith!

They are my firstborn - I auditioned them in a Nottingham hifi shop in
1982 next to some AR18s and Wharfedale wotnots. I loved them for quite a
while - superb upper bass/mid and a nice treble from the T27s. I found
deep bass fine - certainly better than the other smallish budget
speakers of the time. The make is/was LNB, and they were about 100UKP (I
paid 40; mean then as now). On bass - check they're wired properly from
the xover to the terminals. I lent them to a friend for about 5 years,
and he fiddled about with them and put some different terminals on. When
I got them back they sounded terrible - on closer investigation he'd
wired them up incorrectly. I may have buggered that up as well ;-)



The idea is to fit the drivers into the boxes (which I will modify hugely
with a second skin and some crossbracing) using the Ruark crossover, leaving
Rob's 'donor' speakers as intact as possible (for a possible
reversal/restoration) and trying a few different drivers (if necessary)
until I can convince myself I have a pair of unique, stunning 'homebrew'
standmounters that blow away any commercial equivalent at many times the
price.....

;-)

(Or find, for only a little work, if I'm ****ing in the breeze!!)


Live the dream Keith :-)

You can bin them so far as I'm concerned. I thought you might be
interested in the xovers and the T27s. I thought the design was
intriguing (a compact transmission line) at the time, but in the real
world they can't hold a candle to Dynaudio 42s IMO. One last lease of
life in '25th Anniversary Edition' guise won't hurt :-)

Rob