Replacement speaker still sounds blown

[Dogballs5000]

First timer here. Looking for assistance... I have an Ampeg 610HLF. The bottom left speaker (when looking at it) completely blew, torn all the way around the outer part of the cone. Replaced it with an identical speaker (Eminence 6 ohm). Unfortunately, the new one still sounds blown and farty, especially in the low register and at volume. It's a little tough to tell, but it seems like it's being pushed harder than its partners. When I remove it again and play through the remaining 5, the cabinet sounds good.

So it seems like there is a problem with this particular station, and I'm afraid I'm going to blow the brand new speaker if I keep testing things.

Any suggestions for how to go about getting my cabinet operational again?

Thanks!

 

[rickdog]

By any chance, did you get the polarity of that speaker reversed? Do the "battery test" - plug in a speaker cable with a phone plug on the free end, touch the sleeve of the plug to the "-" terminal and the tip of the plug to the "+" terminal on the battery briefly and watch the speakers (grille off). All six should move outward when you make contact.

If you have that one speaker backwards it will go the opposite way. Playing through it that way definitely will damage the speaker.

 

[Dogballs5000]

By any chance, did you get the polarity of that speaker reversed? Do the "battery test" - plug in a speaker cable with a phone plug on the free end, touch the sleeve of the plug to the "-" terminal and the tip of the plug to the "+" terminal on the battery briefly and watch the speakers (grille off). All six should move outward when you make contact.

If you have that one speaker backwards it will go the opposite way. Playing through it that way definitely will damage the speaker.

Unlikely because the cab worked like a champ for 2 yrs up to the blowout. I wired it back in the same way (took photos). But since there just aren’t too many possible culprits, i will do that test if i can find the items. Assume you’re talking 9v battery and a phone jack thats the 3.5mm/1/8” type?

 

[agedhorse]

You clearly have additional problems. This might be a good time to have it correctly diagnosed by a qualified service tech before you damage something else (like your amp).

 

[Wasnex]

Unlikely because the cab worked like a champ for 2 yrs up to the blowout. I wired it back in the same way (took photos). But since there just aren’t too many possible culprits, i will do that test if i can find the items. Assume you’re talking 9v battery and a phone jack thats the 3.5mm/1/8” type?

• Did you buy a brand new factory driver? If you bought used, perhaps it's blown. Or perhaps some of the other drivers have an open voice coil.
• A wire or something else could be in the path of the cone. When the cone moves it vibrates against the obstacle.
• If the replacement cone is moving more than the other cones, could be the wrong driver or it's hooked up out of phase.

 

[rickdog]

Unlikely because the cab worked like a champ for 2 yrs up to the blowout. I wired it back in the same way (took photos). But since there just aren’t too many possible culprits, i will do that test if i can find the items. Assume you’re talking 9v battery and a phone jack thats the 3.5mm/1/8” type?

Yes, 9 V battery, it doesn't even have to be a fresh one (I keep "weak" ones around until they're really dead).

No, I'm talking about the 1/4" phone plug that's often used on (older) speaker cables. Just plug in an ordinary speaker cable with that on the free end. I don't think I've ever seen a 3.5 mm phone plug used for anything bigger than a computer desktop speaker.

 

[eniac]

I have an Ampeg 610HLF. The bottom left speaker (when looking at it) completely blew, torn all the way around the outer part of the cone.

One out of six drivers nearly shredded and the others work fine? What's the history of that cab? Is this a used cab? I'm assuming yes because I can't imagine Ampeg shipping something that would fail in such a fashion.

Something is very seriously wrong. If that were my cab, the very first things I'd do would be to pull all the drivers and check them for authenticity and correctness AND, while the drivers are removed, check the cab for proper wiring. On TB or elsewhere on the Internet you may be able to find info on the exact drivers that cab is supposed to contain, and how the cab is supposed to be wired up.

 

[five7]

Where did you find the replacement speaker. I have never been able to find the correct 6 ohm ten.

 

[SharpCat]

Welcome to TalkBass.

Dunno if you’ve lurked enough to know, but @agedhorse REALLY knows what he’s advising. Do think about letting a tech look at it.

 

[yodedude2]

First timer here. Looking for assistance... I have an Ampeg 610HLF. The bottom left speaker (when looking at it) completely blew, torn all the way around the outer part of the cone. Replaced it with an identical speaker (Eminence 6 ohm). Unfortunately, the new one still sounds blown and farty, especially in the low register and at volume. ...

with that condition, i would suspect that the speaker is not the cause, but rather a symptom. i would suggest switching a known good speaker into that 'bad' spot, but be advised that could cause another blown speaker. however, it woud eliminate the possibility of, or pinpoint, the speaker as the culprit. i.e., if the known good speaker sounds 'blown and farty' in that 'bad' spot, then you know there's an issue with the cab, wiring, etc.

but having a tech check it out is a better idea than my suggestion ~

 

[agedhorse]

I suspect that there is more going on with this than we know.

 

[beans-on-toast]

I would extend the wires and test the speaker out of the cab and see if it distorts.

The replacement might be bad. If it isn’t the same part number, it could be a guitar speaker, unsuitable for bass.

Next examine the baffle cutout for that speaker. Look for voids or loose laminations in the plywood. If yes, the wood needs to be stabilized and filled.

Test that the baffle is not loose where it attaches to the cabinet where the speaker is.

See if the vinyl next to that speaker is loose and possibly flapping.

Look for harness wires that might be in contact with the cone.

See if anything else inside the cabinet is loose and could be vibrating when you play. Check all the fasteners.

 

[Dogballs5000]

Thank you to everybody for the support and flow of ideas. I freely admit my n00bness on the topic and would've taken it to a tech if I had anyone that came recommended. All I get are winces and grimaces when I ask around. Raleigh/Durham NC area.

The cab is probably 15 years old, used from a guy in Myrtle Beach. I've heard that salt air can do a number on equipment, and not just the metal parts. But it worked great for the past 2 years.

The replacement came from FlipTopz, and I waited 6 months for it. I know they're reputable, and the thing looks like a carbon copy of the others. After that long wait, I upped the order to 2 to have a backup. Bruce said they were 6 ohms.

Being aware of the risks of dabbling where I don't belong, I went ahead anyway and looked at all 6 drivers. The same Eminence label, though the tech specs aren't printed on them. Visually, driver conditions look good. The screws holding the drivers in place were fresh black as if they'd never been loosened since factory fresh - I did a number on them even trying to not strip them. One thing I noticed was that it seemed like everything was wired perfectly opposite from what the attached diagram shows. I took the chance and reversed everything to match the flow of the diagram (risky, I acknowledge). In the end, nothing changed.

My lastest test was moving the fresh driver into the bottom right spot and the original bottom right into the danger zone (bottom left). Did the battery test, they all row in the same direction. Plugged in, and the thing sounds normal now. I can't believe my ears. I am 99% sure I have tried this exact combo before. I had previously tried 2 brand new drivers in the bottom position but got the same problem.

It will sound to you clearly that I messed up the polarity, but I assure you I was extremely careful about this. I'd bet the cab on it! (I'm being irrational because we're fighting right now). And reverse polarity wouldn't explain why the original speaker blew. Now, if when I re-wired all 6 in reverse of how I found them, then maybe I did something stupid there (the colors of the wires probably matters). But it didn't seem to affect my troubleshooting, and now it matches the diagram I found somewhere on TB.

I suspect this isn't the end of the story, but I sure hope it is!

 

[Dogballs5000]

I would extend the wires and test the speaker out of the cab and see if it distorts.

The replacement might be bad. If it isn’t the same part number, it could be a guitar speaker, unsuitable for bass.

Next examine the baffle cutout for that speaker. Look for voids or loose laminations in the plywood. If yes, the wood needs to be stabilized and filled.

Test that the baffle is not loose where it attaches to the cabinet where the speaker is.

See if the vinyl next to that speaker is loose and possibly flapping.

Look for harness wires that might be in contact with the cone.

See if anything else inside the cabinet is loose and could be vibrating when you play. Check all the fasteners.

I do admit I need to look around inside more closely. Great tips.

 

[fdeck]

After polarity, I'd be concerned about air leaks. Those can make a perfectly good driver sound perfectly defective.

 

[agedhorse]

Leave it according to the diagram.

Somebody somewhere made a wiring error. This is the sort of thing a tech would verify rather than guessing.

 

[Redridge]

This cab should be around 4ohms, I would verify that first. This cab is wired in a series/parallel configuration).. Sometimes, by disconnecting and re-connecting you can make a connection better (or not, lol).... I would look closely on that particular circuit that went bad... look for frayed ends on all the lugs of both speaker and wires so that they make good contact. If 1 of the speaker is disconnected It should shut off the other speaker its paired to (series circuit). If it doesn't shut off, then that speaker is wired parallel and that doesn't match the diagram posted...

 

[Al Kraft]

Leave it according to the diagram.

Somebody somewhere made a wiring error. This is the sort of thing a tech would verify rather than guessing.

The very first step in any trouble shooting for me is to verify the configuration and integrity of the system against the design specs. You can't effectively troubleshoot and fault isolate a system using the factory specs if the system has been modified, "creatively improved", serviced improperly, etc. The second thing I do is look to be sure any factory approved and recommended configuration and/or component updates have been properly incorporated.

IME skipping those steps just costs time and money in the long run and can easily result in additional damage while operating the system in an unapproved (and possibly unsafe) configuration.

 

[eniac]

Beans-on-toast mentioned the baffle board. That got me to thinking... Maybe you have something like this going on (see the pics)? Was the cab loaned out recently? Did it recently take a hard hit during transportation? For the bad driver position, how's the rear gasket to baffle board seal when you tighten the driver mounting screws? Try to slide a business card between the gasket and the baffle board around the outer edge.

 

[Dogballs5000]

Great tips, much appreciated.
The baffle board looks impeccable. This cab is shared with another at our practice space. We both push it pretty hard, but it doesn't travel much.

BTW, when first powering on, it appears that after a couple seconds, there is an initial speaker synchronized flex (built-in test?) in which all speakers quietly move the same way before returning to rest. I shined a flashlight across them at a shallow angle to better highlight the movement (it's quick). Wonder if this would work similar to the "battery test".

I'm beginning to think that when initially replacing the blown speaker, perhaps I bent one of the clips just enough so that it still looked normal but sat looser when re-connected. Yesterday, I took a needlenose pliers and gently pressed the clip's curled edges down a bit harder. So I'd say 1 or 2 connections might've become more snug... and then it began working again. It could be as simple as that.

My biggest concern now is that I reversed all the wiring from how I found it. Per the diagram I posted, everything matches up except that I don't know what's happening at the top (the + and - at the top of the diagram, which is the circuit board at the top of the cab).

You guys have given me more to look for on the insides, but now that I've got it buttoned up tight again, I am going to take my chances with it. It is sounding good. If I run into problems again, it's off to the pros to handle it. Thanks to everyone!