I hooked up a set of Peavey SP2Gs a couple of weeks ago, just to find
that the horn on one of the two we've got doesn't work. If I hook them
up and bi-amp them, it works just fine, but when it's in "full range",
it doesn't work. Does anyone know what the problem could be?

I took the back of the speaker off where you plug into it to see if
maybe something came loose on the crossover, but everything looked
normal. I did find one thing interesting. There is a light bulb on the
bracket on the inside of the speaker: WTF?!

So if someone could help me out here, that would be great.

-Chris

On 10 Aug 2003 09:40:17 -0700, (ee99ee) wrote:

I took the back of the speaker off where you plug into it to see if
maybe something came loose on the crossover, but everything looked
normal. I did find one thing interesting. There is a light bulb on the
bracket on the inside of the speaker: WTF?!

Small lamps make dandy fuses for speakers, not hi-fi, but
otherwise good characteristics. #51 is a classic for upper
range horns with 1" drivers. Check the lamp first.
Good troubleshooting,

Chris Hornbeck
outraged citizen

Chris Hornbeck wrote in message . ..
On 10 Aug 2003 09:40:17 -0700, (ee99ee) wrote:

I took the back of the speaker off where you plug into it to see if
maybe something came loose on the crossover, but everything looked
normal. I did find one thing interesting. There is a light bulb on the
bracket on the inside of the speaker: WTF?!

Small lamps make dandy fuses for speakers, not hi-fi, but
otherwise good characteristics. #51 is a classic for upper
range horns with 1" drivers. Check the lamp first.
Good troubleshooting,

Chris Hornbeck
outraged citizen


We checked the lamp, but it seemed to work. I'll pull out the ohm
meter and check it later. But would that cause it to quit working just
during "full-range" operation? Remember, I said it works fine during
bi-amp... no problems at all there.

-Chris

Check all components of the crossover (you need to pull it completly to
bits - undo all nuts on the input sockets and remove the eight odd screws
around the edge of the PCB from the back). The large resistors are prone to
overheating and cracking through the middle. Check these and all the chokes
(look like transformers) for continuity. Also, I regularly have to change
the electros in Peavey's SP range, although this will just make the horn
sound funny - not stop it. If the bin is over 5 years old and has seen a bit
of work I would change these as a matter of course. Look for fractured and
dry joints around all the larger components and faulty sockets. Peavey are
very good on parts - just go to your nearest dealer to order them.

The light globe is for speaker protection. It is in series with the horn. If
you try and sink too much current into it (too many watts) the globe will
glow and increase in resistance thus limiting the current across the horn.
Crude but it works reasonably well and is common in PA speakers. I have an
old pair of SP4's and used to blow horns with alarming regularity until we
retro-fitted the protection.

Regards - Pat
www.patski.cjb.net


"ee99ee" wrote in message
om...
I hooked up a set of Peavey SP2Gs a couple of weeks ago, just to find
that the horn on one of the two we've got doesn't work. If I hook them
up and bi-amp them, it works just fine, but when it's in "full range",
it doesn't work. Does anyone know what the problem could be?

I took the back of the speaker off where you plug into it to see if
maybe something came loose on the crossover, but everything looked
normal. I did find one thing interesting. There is a light bulb on the
bracket on the inside of the speaker: WTF?!

So if someone could help me out here, that would be great.

-Chris

You can buy the entire crossover from a Peavey Dealer, and that maybe easier
than messing with it. They are not that expensive.

Something to look for is bad switching jacks. Most jacks on Peavey crossovers
are switching types. Sometimes they fail to make good contact. Frequently you
can use a small screwdriver to bend the offending swich contact. Of course,
replacing them is the best bet.

ee99ee wrote:
I hooked up a set of Peavey SP2Gs a couple of weeks ago, just to find
that the horn on one of the two we've got doesn't work. If I hook them
up and bi-amp them, it works just fine, but when it's in "full range",
it doesn't work. Does anyone know what the problem could be?

The crossover.

I took the back of the speaker off where you plug into it to see if
maybe something came loose on the crossover, but everything looked
normal. I did find one thing interesting. There is a light bulb on the
bracket on the inside of the speaker: WTF?!

The light bulb is a limiting device in series with the horn to keep it
from being damaged. Make sure it's okay. Get out the ohmmeter and trace
everything from the input to the output.

Also check the series capacitor on the crossover. They will go bad sometimes.
But look first at contacts and switches and that lamp.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."