Acoustic rattling in RM20

[ricky]

I saw the post about rattling in an RM100 and thought I would see if any of you have been able to deal with the noises inherent in the RM20 Combo. At Rob's suggestion, I have tried the tube dampers but I still get the noises. it does not happen if I use the external speaker out. Anybody have any success?

 

[Jaded Faith]

The answer might simply be either another speaker of a bigger cab for the combo.

 

[ricky]

The speakers is fine. It rattles the same with a JBL or a Cellestion. Anyone out there in MTS land have an RM20 head cabinet they want to part with?

 

[Jaded Faith]

I didn't mean to imply there was a problem with the speaker. I simply meant that it would have too much bass response for such a small enclosure. Remember the stock speaker was a Greenback, with little bottom end.

Many do not realize how important the enclosure and it's materials are. It's not just a box for a speaker. The materials used, their thickness and the dimensions all play a huge roll in the tone. You can stick a large, beefy driver in a tiny enclosure with thin wood and not expect rattles and resonances really.

 

[Jaded Faith]

Some things I do in the shop on a regular basis to help customers deal with sympathetic combo enclosure resonance include:

1: Apply threadlocker or glue to all the screws and fasten them tight

2: Build replacement baffles for the speakers to mount on with thicker wood

3: Use a vibration-reducing rubber product where all panels meet (like your back panels. I use various products from McMaster-Carr with great results in any amp. A simple DIY part would be 8709K22 from their website.

4: Make sure the speaker is fastened securely and threadlock the nuts and bolts.