Ampeg BA500 "flubby" help??

mdacox

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Mar 7, 2017
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Asheville, NC
Hey guys, just recently started playing bass for this new band, and picked up a Ampeg BA500 combo. It's in pretty good shape for being an '02, but after trying it out at practice for the first time, I'm really worried.
So in standard tuning, just playing an A on the E string sounds big and full, maybe a tiny bit of cabinet rattle, but going down to an open E, the volume is noticeably quieter in volume, and whats worse, when the amp is just at normal playing volume, and the bass EQ turned up (just trying to get a good sound to my ears), it gets horribly flubby like the one of the speakers is shredded. This is with the gain at maybe 4 and the master at 4.5, the bass EQ knob on 6, most everything else right in the middle except the EQ sliders very very slightly biased to have more bass and cut a little treble. I removed the grill and took the speaker out that I thought sounded like the culprit, but it looks fine, no holes or rips. It's like the speaker can't handle the frequency of just a low E, which I know doesn't make any sense, but that's the best way I can describe it. Any advice or anyone encountered this before? Thank you so much in advance! I have not tried a different bass, but I doubt that's the problem. I tried to attach a file of the pic of the speaker, let me know if it worked.
IMG_20170307_224826.jpg
 
I'm afraid I've got some bad news for you in addition to what others have said. IF your pictures are accurate, your drivers have been ruined by over-excursion. Just inside the accordion surround, you can see creasing of the paper about 1/4" inside from the edge. This is classic over excursion damage (too much power for the drivers, often at frequencies below what the cabinet is tuned to safely reproduce. This damage, which usually includes damage to the spider that you can't see, will greatly change the parameters of the driver which are what the cabinet tuning is based upon. This means that the cabinet becomes even less capable or reproducing low frequencies without greatly increased distortion.
 
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Thank you for all the responses guys! I will bring that EQ back down and try at the gig tomorrow.
...Just inside the accordion surround, you can see creasing of the paper about 1/4" inside from the edge. This is classic over excursion damage (too much power for the drivers, often at frequencies below what the cabinet is tuned to safely reproduce...
agedhorse, I'm going to attach some more pictures, could you tell me exactly where the crease is? Thank you. These pics are of the speaker that was out of the cab in the first picture. On one picture I put little arrows to the crease I believe you are talking about.
Thanks again!
 

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Thank you for all the responses guys! I will bring that EQ back down and try at the gig tomorrow.

agedhorse, I'm going to attach some more pictures, could you tell me exactly where the crease is? Thank you. These pics are of the speaker that was out of the cab in the first picture. On one picture I put little arrows to the crease I believe you are talking about.
Thanks again!
Nope, inside of that on the paper surface. If you look from the back, it's where the reinforcement stops.

This problem started occurring as amp power increased, which caused manufacturers to look at (and choose) different cone edge geometries and surround styles. The most common is the angled edge up into the surround, with an M roll (or double-roll) surround profile. Much more linear under higher displacement conditions with MUCH less edge stress/fatigue.
 
I just looked again, I see what you're talking about! It's the very faint creasing in the paper that's right next to the edge I pointed at correct? That crease makes that much of a difference? Thank you for the info!