Peavey 15" Cab Black Widow Speaker Buzz

[Renzo Gasperini]

I'm restoring an early 80's Peavey 15" Black Widow cab and running into an issues I can't seem to resolve. The speaker is connected to a Peavey Mark VI bass amp, which sounds great on another Peavey 15# cab that I have. When I connect the amp to the cab I'm restoring I get buzzing at the low notes. I called Peavey and they told me to check the mounts, remove the magnet, inspect the coil and cone as well as clean any debris in the voice coil channel of the magnet. So I used heaver T-Nuts and remounted the speaker, cleaned the voice coil groove, checked the ohms consist 7 ohms and even checked the wires and speaker movement. Everything seems good and sounds good when I send online bass speaker sounds through it via You tube video. When I put it all together and hit those low notes I get the same unchanged buzzing that I don't hear with my other 15" Black Widow cab. See attached photos. Any ideas? Are those scratches inside the voice coil the problem? If so is it fixable?

 

[N Scott Shaw]

A couple of other things to check if the most common problem has been checked.

The spyder suspension at the base of the cone. check all the way around and make sure its still glued to the basket.

Check the voice coil. Sometimes a bubble will develop on the coating of the coil.

 

[abarson]

Mods, please move this to the AMPS section.

 

[Giffro]

I'm restoring an early 80's Peavey 15" Black Widow cab and running into an issues I can't seem to resolve. The speaker is connected to a Peavey Mark VI bass amp, which sounds great on another Peavey 15# cab that I have. When I connect the amp to the cab I'm restoring I get buzzing at the low notes. I called Peavey and they told me to check the mounts, remove the magnet, inspect the coil and cone as well as clean any debris in the voice coil channel of the magnet. So I used heaver T-Nuts and remounted the speaker, cleaned the voice coil groove, checked the ohms consist 7 ohms and even checked the wires and speaker movement. Everything seems good and sounds good when I send online bass speaker sounds through it via You tube video. When I put it all together and hit those low notes I get the same unchanged buzzing that I don't hear with my other 15" Black Widow cab. See attached photos. Any ideas? Are those scratches inside the voice coil the problem? If so is it fixable?

Hi @Renzo Gasperini I had some buzzing from my Peavey 1820 cab (18"BW and 2 10"Scorpions) a few years ago and it turned out to be the actual loom of wires from the speakers leaning against the back of the speaker cone...i moved the wires away and hot melt glued them to the wall of the side of the cab..fixed the issue. Worth checking.
Also Peavey may have replacement basket if you enquire with them..they used to have a bunch of them for 15" and 18" drivers..not sure of the cost but would be cheaper than a brand new unit.
Also have a look here Invalid Link Removed

This is my rig..I use a lighter rig these days but this is still my old faithful reserve setup...

You said you checked the speaker movement..did you LIGHTLY push against the cone..in and out a few times to see if you can detect any scratchy noises?
Best of luck with it.

 

[agedhorse]

Try it outside away from the thousands of things in the room that can buzz and mimic your symptoms.

 

[Renzo Gasperini]

Hi @Renzo Gasperini I had some buzzing from my Peavey 1820 cab (18"BW and 2 10"Scorpions) a few years ago and it turned out to be the actual loom of wires from the speakers leaning against the back of the speaker cone...i moved the wires away and hot melt glued them to the wall of the side of the cab..fixed the issue. Worth checking.
Also Peavey may have replacement basket if you enquire with them..they used to have a bunch of them for 15" and 18" drivers..not sure of the cost but would be cheaper than a brand new unit.
Also have a look here Invalid Link Removed

View attachment 5442243

This is my rig..I use a lighter rig these days but this is still my old faithful reserve setup...

View attachment 5442247

You said you checked the speaker movement..did you LIGHTLY push against the cone..in and out a few times to see if you can detect any scratchy noises?
Best of luck with it.

All good advice here, will check to see about wires touching the speaker cone. Will also try lighting moving the speaker and listen for any scratching. If you looked a t the photos, there are some scratch marks on the inside of the voice cone, but I think I cleared that out. So not sure what caused it or if that's the problem. Nice rig, I have the same amp too.

 

[agedhorse]

Try it outside.

 

[crazyBassClown]

hich sounds great on another Peavey 15# cab that I have.

I'd suggest swapping the drivers between the cabs to determine if the problem is the driver or the cab in the first instance given you have another to do it with. Swap the cabs so they are both in the same spot to check if it buzzes for both and it is something other than the cab ala agedhorses suggestion.
When you narrow it down then go from there and fix the driver or work out what in the cab is buzzing.

Edit: I got an ampeg micro210 recently that the bottom speaker was buzzing on and it turned out that the wire from the terminal to the cone was in a position where it hit the speaker frame if moving far enough, a slight tweak of the direction of that and the buzz is all gone.

 

[Ostie]

Check for loose braces, cleats, handles, or grill cover.

 

[Giffro]

Check for loose braces, cleats, handles, or grill cover.

Good suggestion.
I know in the case of my 1820 Peavey cab pictured here , that the grille is velcro-ed on using industrial strength coarse velcro patches, and the first time many years ago when I needed to get the grille off I wasnt sure how it was attached.
I ran a medium sized screwdriver at differing spots along the edge and slightly behind the aluminium frame very, very gently down one side prising the grille a bit at a time away from whatever was holding in on..I thought at the time it was possibly a press fit but after gently working away with the screwdriver it started to ease away and I heard the familiar rip sound of velcro. The velcro was applied in large patches from memory. 1 large patch top rh corner 1 large patch middle side, 1 large patch bottom rh corner. The same on the opposite side with a middle patch in the top and middle patch along the bottom too..so all up on my 1820 cab, about 8 patches. It is quite likely this arrangement and placement of patches was native to just my particular 1820 sized cab..smaller 15" cabs may vary, but still I would be tempted to say its still a velcro grille press fit made in a similar fashion.
The grille frame I remember seemed to me to be quite a flimsy construction with the cloth attached once it was removed so be careful prising the edges up if using a screwdriver to break the velcro seal, because you could break the thinner wood of the grille frame or damage the aluminium if too aggressive.

 

[micguy]

On tours decades ago (this may or may not still be a thing) PA cabinets were labelled with a's and b's - they kept track of which way was up on every cabinet, and alternated putting things right side up and upside down - one tour stop would have all the woofers one way up, the next would have them the other way 'round. There were cabinets where you had to run them one way up, and techs would sometimes take woofers out and rotate them in their orientation on a regular basis. Yesterday, I was at a conference, and the presenter was tasked on a tour (years ago) with rotating and/or changing rubbing/failed woofers - while the gig was in progress (ear protection is absolutely mandatory for this, and probably still not enough. The suspensions on woofers tend to settle over time, so rotating their orientation was (and may still be) key to making them last longer.

So, make a mark on the top of the edge of the woofer, unscrew it, rotate it 180 degrees, and bolt it back in. If it's a rub from settling, you may be able to fix it for zero dollars.

And oh, by the way, if you have unused 1/4 inch jacks (you only have one plugged in, even though there are two of them, the leak/chuffing noise through the unused one can sound very "buzzy" - it'll sound very mechanical, even though it isn't - try plugging that hole up and see if that helps.

 

[Fishheadjoe]

Sit on the cab while playing
Fishheadjoe

 

[agedhorse]

Rotating woofers hasn’t been an issue for about 70 years, not since modern adhesives and materials have been used. The only ones I recall were some early Altec drivers that used the sticky surround treatment, but those were from the 1950’s. The surround dope would creep after many years in one orientation. There may have been others (also in the HiFi world) but it’s been many decades.

 

[Giffro]

On tours decades ago (this may or may not still be a thing) PA cabinets were labelled with a's and b's - they kept track of which way was up on every cabinet, and alternated putting things right side up and upside down - one tour stop would have all the woofers one way up, the next would have them the other way 'round. There were cabinets where you had to run them one way up, and techs would sometimes take woofers out and rotate them in their orientation on a regular basis. Yesterday, I was at a conference, and the presenter was tasked on a tour (years ago) with rotating and/or changing rubbing/failed woofers - while the gig was in progress (ear protection is absolutely mandatory for this, and probably still not enough. The suspensions on woofers tend to settle over time, so rotating their orientation was (and may still be) key to making them last longer.

So, make a mark on the top of the edge of the woofer, unscrew it, rotate it 180 degrees, and bolt it back in. If it's a rub from settling, you may be able to fix it for zero dollars.

And oh, by the way, if you have unused 1/4 inch jacks (you only have one plugged in, even though there are two of them, the leak/chuffing noise through the unused one can sound very "buzzy" - it'll sound very mechanical, even though it isn't - try plugging that hole up and see if that helps.

I used to use these for that purpose..available from Ebay..1/4 inch dummy plugs..made of rubber.
Neutrik NDJ Rubber Dummy 1/4 inch 6.35mm Jack Plug Socket Protection | eBay

 

[Renzo Gasperini]

Mods, please move this to the AMPS section.

I'm not sure how to do that can you help?

 

[abarson]

I'm not sure how to do that can you help?

Mods already took care of this.

 

[rickster4003]

Hi @Renzo Gasperini I had some buzzing from my Peavey 1820 cab (18"BW and 2 10"Scorpions) a few years ago and it turned out to be the actual loom of wires from the speakers leaning against the back of the speaker cone...i moved the wires away and hot melt glued them to the wall of the side of the cab..fixed the issue. Worth checking.
Also Peavey may have replacement basket if you enquire with them..they used to have a bunch of them for 15" and 18" drivers..not sure of the cost but would be cheaper than a brand new unit.
Also have a look here Invalid Link Removed

View attachment 5442243

This is my rig..I use a lighter rig these days but this is still my old faithful reserve setup...

View attachment 5442247

You said you checked the speaker movement..did you LIGHTLY push against the cone..in and out a few times to see if you can detect any scratchy noises?
Best of luck with it.

Nice system! Would love to play through that. Always wanted one of those heads. I still have my Peavey CS-400 from the 80's.