Acme lowB-2 woofer distortion

c3powil

c3powil

Apr 18, 2008
395
214
4,946
North of ATL, GA
#1
Hi guys. Hopefully you can help me come to a conclusion.

I recently acquired a series 1 Acme LowB-2. The guy I bought it from was playing a gig when I picked it up and was using the cab the whole gig. It sounded great. Once the band was packing up, he demo'd it for me and it showed no signs of farting or distortion.

Now, at home, I notice an annoying distortion that creeps up the longer I play. At first it is non existent, but it becomes more and more noticeable and REALLY annoying at bedroom volume. Now, if I were playing a rock gig it probably wouldn't be a big deal because it's hard to hear in a loud room. The bass still sounds pure and smooth, but its almost as if something is rattling around. I confirmed this by turning both horn and mid attenuators off. It sounds like the right woofer is distorting, even at low low volumes.

Now I know what you're thinking. Active bass? Yes. Check the battery. Well, I know it's not the battery because I plugged my passive guitar in with the same result. Also YouTube videos get the same treatment.

I even bypassed all foot pedals and effects by going straight into the power amp with my bass.

What else could it be?

If it really is the woofer, is it even worth replacing? I bought the cab for 225, and I'm not very keen on spending more money right now. I have no idea what it would cost to replace. Could probably do the work myself, though.

The cab sounds fantastic, though, and I want to get an f deck to protect it. Do you think getting an f deck and cutting out those low lows would actually cut the distortion too?

Thank for the help
 
#3
I am using a Crown CE1000 going 425 Watts into the acme. I'm not sure what he was using but I want to say it was a GK 400rb or something like that. He was using the acme by itself.

I've looked and haven't seen anything but I'll check again when I get home.
 
#8
IMO the clanking sound shouldn't be there. I bought one of mine from a guy who was selling two of them. I picked "the one on the bottom." There was no way to test it at his place. It clanked. At low volume too. I took it back and exchanged it for one on top. I'm glad he was a good guy.
 
#10
I'm using a sansamp bass di as a pre. I've turned the volume on the bass way down to to ensure no pre or power amp clipping. A single channel puts out 425 Watts I believe. No need to bridge.

To be clear, I get this distortion at low bedroom volumes and never noticed it with my avatar cab. I know I've read that the wide frequency response of acme cabs tends to make problems, that were at first unnoticeable, very noticeable.
 
#11
The only problem I have had is that Acme products have low sensitivity. That means you have to put more power into them than you would expect. Your 425W should cover that in spades.

Crown power amps need, IIRC, a goodly amount of signal to get them to their full output. I’m wondering if the Sans Amp has sufficient output to power the crown properly. The channel faders on the Crown should be at maximum and volume controlled from the pre.
 
#14
Okay, so I tried clipping the crown power amp. It was actually much more difficult than I expected. But I'm getting PLENTY of volume from it, and the distortion is never present when I start playing unless I play for a while, stop, and then start again soon after. The distortion is only present after warming up for a few minutes. I wish I had another power amp to use. Maybe I'll have to take it by guitar center and use a variety of amps and basses and see if it buzzes then.
 
#15
If one woofer is bad, they are probably both bad. Yeah, you can get replacement woofers from Andy of Acme. He will charge you full price, about $90 for each woofer but when you return your bad speakers, you'll get like a $25 refund for each one. You'll use the same shipping box for the return.

If you replace your old woofers, you'll need about 10 hours of low volume break-in time on the new ones or you'll mess them up.
 
#19
*UPDATE*

Took the cab to the store and tried out a Fender Rumble 500. Distortion was still present.

However, after the sales guy helped me remove the grill and speaker, we determined that there was no visible damage. We screwed the speaker back in and.... what do you know... the "distortion" was significantly less than it was before. All we did was inspect the speaker and take off a bit of the old cracked gasket material that got pulled off with the speaker.

This makes me think it was something hindering proper movement of the cone. It sounds way better now, and when i got home, I didn't really notice much of any distortion at all.

I'm a happy camper.

Although if there's one thing that I've learned from this experience... it's that those new Fender Rumble heads sound REALLY sweet.

And if there's a second thing I've learned, it's that I got a really good deal on a really sweet sounding cab. Having the chance to A/B it against the other Fender Rumble cabs and my Avatar cab made me realize what a bassy and wide frequency cab it is.
 
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