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Hi all,

Im usually found posting in the Rec.Games.Pinball forum, but I came
across this group while searching for some info to help repair my newly
acquired CV D-9's.

I'm the original owner of a set of D-5's since new back in 1984 or so,
and I decided I needed a bigger set of speakers for the larger home
we've moved into. These speakers having held up to the rigors of loud
and continuous partying, I figured the big brother to these should be
fine.

So to that end, I found a slightly abused set, but figured I'd delve
into the speaker repair bit as a break from pinball and video games for
a while.

The set I found is original, it seems to be an earlier version, as the
knobs on the crossovers are different than the silver center knobs on
sets I've seen elsewhere...

Here's the status. Both woofers have deteriorated foam. I have just
finised refoaming them myself with a correct set of new flat edged CV
foam for these woofers. So far so good, no rubbing of the voice coil
etc.

One tweeter was shot, I had a spare that I know works, (bench tested
for sound) and I verified that the small ribbon lead on the diaphram
of the shot tweeter was in fact broken from the voice coil. I actually
was able to solder it back, but it still has no continutity between
lugs, and still produces no sound.. Guess the voice coil is also broken
somewhere in the winding...

Both crossovers pots are completely frozen. I actually tried to free
up the adjustments with a pair of pliers, (with the knobs off of
course) and actually broke one of the grey plastic adjustment
cylinders...

So I hooked everything back up, (Ive also verified on the bench that
the 4 mids also work), but upon plugging them in, it just doesn't have
the volume they should. In fact the mids and tweeters while producing
sound, is so low, that it almost sounds like they aren't working at
all.

So, is this purely a function of the crossovers? I know that the
adjustments on my D-5's just aren't THIS dramatic as to make it seem
like there's no sound coming out at all when I turn it down, so even if
they were frozen at the bottom of the output range on all 4 pots, I'd
expect way more volume... The fuses are good, taking them out cuts the
woofers all together. and I've checked all the connections for proper
polarity . All black leads to the neg side, Blue for the pos highs,
two yellows for the pos mids, and purple for the pos on the woofer.
Red to the red input post, and the remaining black lead to the neg
input.

What do I do to turn up the volume on these? I've swapped one side for
one of my D-5's and the volume is measureably lower versus that when
one is on the right and the other is on the left..

Thanks in advance for any help, and forgive the long winded post.

Vinny

[[email protected]]

Bob, thanks for the reply and the suggestions.

Im in agreement about the pots, as upon closer inspection, the midrange
pot (which has a lead surrounded by clear plastic tubing as an
insulator running next to it) had melted the plastic insuation. I had
assumed as much, and the plating on said pot is also a bit toasty..
flaking off as a matter of fact.

Again, my suspicions knowing the history of the ownership, as well as
the propensity for people to try and drive these monsters all the way
"to eleven" Im really not surprised.

However, Im not sure where to locate the correct pots for this.
Standard electic guitar pots are usually 250 or 500 ohms, and with
these all being fried, Im not able to get a reading off of them for
comparison. They have a number stamped in the back, but no indication
of their ratings.

Lastly, I was able to wire these back up after verification that I had
inadvertantly wired them up incorrectly in the first place. Seems the
Red and Purple wires, were backwards.. meaning the Red lead is NOT the
lead that connects to the positive input at the back of the speaker...
but in fact is the postive lead for the Woofer.. Switching these two,
has solved 90 percent of the problems I was having with the mid range
output being so anemic. Now to change out the pots, and get these back
up to snuff.

Thanks again for the reply, and if you know what value these pots are
supposed to be, and/or where I can find any, I'm all ears.

Vinny

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However, Im not sure where to locate the correct pots for this.
Standard electic guitar pots are usually 250 or 500 ohms, and with
these all being fried, Im not able to get a reading off of them for
The cheap way to buy them is as L-pads. As standard parts, these are cheap
and available. They could have custom values determined by a CAD program,
but they would not be affordable, unless purchased from Cerwin-Vega. My
guesstimate is for an 8 ohm part.

Have a look at
http://www.partsexpress.com/webpage....Group_ID=1 96
My choice for a guess: p/n 260-252, or 260-262, largely determined by what
fits.


Bob, thanks again for the info and the lead. I'll post back with
results. Just got finished cleaning the cabinets, grills, etc., and
they dont look half bad, and the sound isn't too shabby either. Still
breaking in the new foam, so I haven't driven them too hard yet, but
they do put out some bass... Good replacement for the D-5's that were
handling sound for this half of the home.

Vinny

http://world4.monstersgame.co.uk/?ac=vid&vid=47073225