Speaker Replacement Advice Needed

Archived from groups: rec.audio.pro (More info?)

> A few years ago I acquired an old Peavey KB-100 keyboard/vocal amp
> (75w, 3 inputs) and I'm trying to refurbish it. Having successfully
> replaced the frayed and broken power cord, I noticed that the main 15"
> (8 ohm) speaker cone is torn near the edges. I'd like to replace the
> speaker with something that will sound reasonably good for vocals.
> Right now it sounds muddy and indistinct when sung through, despite
> the fact that the tweeter seems to be working; I'm guessing it lacks
> mids. I'd like to spend around $100, but could be convinced to spend
> more if neccessary. Any hints about what to get would be very much
> appreciated.

The speaker can be repaired, which is the best and least expensive solution.
A different woofer will have different requirements for the enclosure and
porting, which affects a lot more than just bass. Be sure to re-edge it
with the same suspension material, probably cloth.

And just because the tweeter works doesn't mean it's the proper sensitivity
to match the woofer. Often they just slap a piezo horn in. Not sure what
it's got for EQ, but for the typical dynamic mic you'll want to rail the
high treble (14+kHz) to the roof, about +12dB, bump up the 2.5kHz by 2dB,
drop the 4.5kHz by about 6dB, some extra bottom end usually helps (100Hz
+3dB), and if the treble horn lacks sensitivity you'll have to boost
everything above 2kHz accordingly. Then you've compensated for (most of)
the disproportions of the gear, now you can compensate for your voice and
how it interacts with the mic. You should really have at least a 9-band EQ
for the job, even a guitar stomp box. There's where your money should be
spent.

Archived from groups: rec.audio.pro (More info?)

On Sun, 31 Oct 2004 17:38:44 -0500, David Abrahams
<dave@boost-consulting.com> wrote:

>Reconing looks like a several-hour job for a non-expert like me from
>what I can see on the web, and since I don't think I'm hearing the
>tears (about an inch long each, oriented radially) yet, I was hoping
>the sound could be improved by replacing the speaker. It looks like
>I might be able to get some mileage out of plain Elmer's glue if I'm
>going to try to salvage the existing speaker. Is that insane?

I've always had good results by watering down Elmer's glue,
soaking a cigarette paper and applying like a patch. After it
dries, it's usually stronger than the original and with minimal
effect on mass.

Good fortune,

Chris Hornbeck

Archived from groups: rec.audio.pro (More info?)

> Sug, thanks for the feedback
>
> > The speaker can be repaired, which is the best and least expensive
> > solution.
>
> Reconing looks like a several-hour job for a non-expert like me from
> what I can see on the web, and since I don't think I'm hearing the
> tears (about an inch long each, oriented radially) yet, I was hoping
> the sound could be improved by replacing the speaker. It looks like
> I might be able to get some mileage out of plain Elmer's glue if I'm
> going to try to salvage the existing speaker. Is that insane?

I thought you said it was torn at the edge, the suspension alone can be
replaced, I get them done for $25. Reconing may not be necessary.

> > And just because the tweeter works doesn't mean it's the proper
sensitivity
> > to match the woofer. Often they just slap a piezo horn in.
>
> I think that may be what it is. It looks a lot like
> http://www.cybermarket.co.uk/ishop [...] 00-299.jpg, at least
> from the outside.
>
> Do you think I can do better by replacing it?

Yeah, that's a piezo horn, worth about $3.50. Getting a compression horn
that is a reasonable sensitivity match and also fits into the cabinet will
be tricky. You shouldn't put them on an angle either, their rectangular
waveguide (plastic assembly) is designed to disperse the treble
horizontally. I doubt it will be worth the effort, cheap compression horns
are only marginally better than piezo horns, they can just take a lot more
power and drive longer distances, qualities you shouldn't expect from a
KB100.

> Just to be clear: you mean a 9+-band guitar eq stomp box would
> probably suffice?

That's pretty much exactly what's included on budget mixers, and there
should be an effects loop on the amp, best spot to put it.

> Really? Wow, I wonder if my old QuadraVerb could be put to good use
> here. I don't remember for sure but I think it has some EQ
> capabilities. Can't stand the sound of the delay effects, but the EQ
> might be OK.

I would want that EQ to be much more accessible than a clumsy GUI like that.
You'll want different settings for each room and speaker position relative
to the mic. Nothing like good ole faders. That's worth the $35 or so
alone.

Archived from groups: rec.audio.pro (More info?)

On 30 Oct 2004 20:55:57 -0700, David Abrahams
<dave@boost-consulting.com> wrote:
> Hi, and thanks for reading --
>
> A few years ago I acquired an old Peavey KB-100 keyboard/vocal amp
> (75w, 3 inputs) and I'm trying to refurbish it. Having successfully
> replaced the frayed and broken power cord, I noticed that the main 15"
> (8 ohm) speaker cone is torn near the edges. I'd like to replace the
> speaker with something that will sound reasonably good for vocals.
> Right now it sounds muddy and indistinct when sung through, despite
> the fact that the tweeter seems to be working; I'm guessing it lacks
> mids. I'd like to spend around $100, but could be convinced to spend
> more if neccessary. Any hints about what to get would be very much
> appreciated.
>
> Thanks again in advance,
>

I successfully patched speakers and they remained Good Enough until the
speaker blew outright. The suggestions here are roughly equivalent to
mine.

With the Peavey speaker, check whether or not it's a "Replacable Basket"
model. If your amp is a Black Widow variant (BW Equipped) it probably
is--and I'm pretty sure the Scorpion speakers are as well.

My biggest complaint with my KB-100 is the weight, but it was unbeatable
at the price point when I bought it--at least locally.

Archived from groups: rec.audio.pro (More info?)

>
>Hi, and thanks for reading --
>
>A few years ago I acquired an old Peavey KB-100 keyboard/vocal amp
>(75w, 3 inputs) and I'm trying to refurbish it. Having successfully
>replaced the frayed and broken power cord, I noticed that the main 15"
>(8 ohm) speaker cone is torn near the edges. I'd like to replace the
>speaker with something that will sound reasonably good for vocals.
>Right now it sounds muddy and indistinct when sung through, despite
>the fact that the tweeter seems to be working; I'm guessing it lacks
>mids. I'd like to spend around $100, but could be convinced to spend
>more if neccessary. Any hints about what to get would be very much
>appreciated.
>
>Thanks again in advance,
>
>Dave
>
>

Which speaker is in it. I suspect that it is the lower end stamped frame
speaker that Peavey puts in their least expensive cabinets. Upgrading to a
Scorpion or a black Widow would make a fair amount of difference.

If you just want to fix the radial tears, I have had good results with Silicone
seal.

Richard H. Kuschel
"I canna change the law of physics."-----Scotty

Archived from groups: rec.audio.pro (More info?)

Chris Hornbeck <chrishornbeckremovethis@att.net> wrote in message news:<fptao05o8m1mg36uf1hep30gum0qqs2ltt@4ax.com>...
> On Sun, 31 Oct 2004 17:38:44 -0500, David Abrahams
> <dave@boost-consulting.com> wrote:
>
> >Reconing looks like a several-hour job for a non-expert like me from
> >what I can see on the web, and since I don't think I'm hearing the
> >tears (about an inch long each, oriented radially) yet, I was hoping
> >the sound could be improved by replacing the speaker. It looks like
> >I might be able to get some mileage out of plain Elmer's glue if I'm
> >going to try to salvage the existing speaker. Is that insane?
>
> I've always had good results by watering down Elmer's glue,
> soaking a cigarette paper and applying like a patch. After it
> dries, it's usually stronger than the original and with minimal
> effect on mass.

Papier mâchè is more familiar to me than reconing.
I used rice paper, and it seemed to work out just fine. Thanks!

-Dave

Archived from groups: rec.audio.pro (More info?)

"Sugarite" <nobody@home.com> wrote in message news:<nBlhd.1554$14.905@read1.cgocable.net>...

> > I think that may be what it is. It looks a lot like
> > http://www.cybermarket.co.uk/ishop [...] 00-299.jpg, at least
> > from the outside.
> >
> > Do you think I can do better by replacing it?
>
> Yeah, that's a piezo horn, worth about $3.50. Getting a compression horn
> that is a reasonable sensitivity match and also fits into the cabinet will
> be tricky. You shouldn't put them on an angle either, their rectangular
> waveguide (plastic assembly) is designed to disperse the treble
> horizontally. I doubt it will be worth the effort, cheap compression horns
> are only marginally better than piezo horns, they can just take a lot more
> power and drive longer distances, qualities you shouldn't expect from a
> KB100.
>
> > Just to be clear: you mean a 9+-band guitar eq stomp box would
> > probably suffice?
>
> That's pretty much exactly what's included on budget mixers, and there
> should be an effects loop on the amp, best spot to put it.
>
> > Really? Wow, I wonder if my old QuadraVerb could be put to good use
> > here. I don't remember for sure but I think it has some EQ
> > capabilities. Can't stand the sound of the delay effects, but the EQ
> > might be OK.
>
> I would want that EQ to be much more accessible than a clumsy GUI like that.
> You'll want different settings for each room and speaker position relative
> to the mic. Nothing like good ole faders. That's worth the $35 or so
> alone.

Well, it's not a big improvement in the GUI department, but I was
having feedback problems so I picked up a used Behringer Feedback
Destroyer Pro, which I'm sure can handle most of my EQ requirements.
I note that the manual says emphatically that this unit is not
intended for mics to be connected directly, but I'm wondering just
what the downside could be. For my particular cheapo setup, it could
be ideal as one of the mics really could benefit from having the
preamp.

Any clues?

Thanks again for your very generous help.

Archived from groups: rec.audio.pro (More info?)

On 5 Nov 2004 11:26:03 -0800, dave@boost-consulting.com (David
Abrahams) wrote:

>Well, it's not a big improvement in the GUI department, but I was
>having feedback problems so I picked up a used Behringer Feedback
>Destroyer Pro, which I'm sure can handle most of my EQ requirements.
>I note that the manual says emphatically that this unit is not
>intended for mics to be connected directly, but I'm wondering just
>what the downside could be. For my particular cheapo setup, it could
>be ideal as one of the mics really could benefit from having the
>preamp.

Probably the downside is simply that the unit has line level
connections. A directly-connected mic won't work.

As always, when using this sort of gear, remember that your first
priority is to get the sound GOOD. Getting it LOUD is secondary.
Other things can often be quieter. The most general complaint from
today's audiences is of over-amplification.

Many times I've walked in to a theatre which has been comprehensively
tweaked for feedback rejection. I ask the operator to play his
favourite CD through the system. If it sounds terrible, I suggest he
switches out that 1/3 octave graphic eq that's looking like a relief
map of the Himalayas. Having got the quality back, we can think
about a volume structure for the show.

Sometimes, when an operator's got ears, you see channel EQ doing it's
best to negate the main EQ :-)

CubaseFAQ www.laurencepayne.co.uk/CubaseFAQ.htm
"Possibly the world's least impressive web site": George Perfect