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Fender Rumble Club

#7,042
eric_B said:
Follow up to my plan to cover some inner sides of my Rumble V3 100 with acoustic foam.
Here are some pictures of the inside of the combo and the speaker.
The cabinet is basically a wooden box with a separate section for the amp with just a hole for the speaker wire.

I decided to cover the top, left side and lower back.
Non-permanently for now so I still can choose what I prefer.

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Next tweak would be replacing the speaker, probably with a Basslite S2012.
Not sure if it is worth the € 138 (or USD 150).
Click to expand...

Very nice work you made.And the foam is very good quality indeed.
 
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#7,045
Big Hoss said:
Please excuse my ignorance but what is the purpose of the foam?
Click to expand...

There's nothing to excuse. If you don't ask, how will you know?

The foam is to deaden resonances from the wooden cabinet. It is used more extensively in sealed speaker system, where it can "fool the driver into thinking it's in a bigger box" than it really is. I lined the inside of a subwoofer that I built for my home theater system. Since I did that before assembling the sub, I have no idea if it makes a difference in the sound. Also, I believe the Rumble cabs are made of a type of plywood while my sub and many other bass guitar cabinets are made from MDF (medium density fiberboard). I do not know which material is more resonant or inert.

This is hardly an expert observation, but it should help until someone who has a better idea of what they're talking about chimes in.
 
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#7,047
Big Hoss said:
what is the purpose of the foam?
Click to expand...
It should come as no surprise that a naked speaker cabinet is going to sound 'boxy'; 'wooden', and/or 'hollow' . Proper acoustic treatment eliminates that. Plus it will also break up and absorb standing sound waves and rebounding waves inside the cabinet. Ideally you want only air coming out of your ports, and not sound. All the sound should be coming from the cone(s) of your speakers. Lining your cabinet will also benefit your clarity of bottom end effectively tightening it up. Same thing for the entire mid-range especially the all important low mids where the real punch and attack lives. The absorptive qualities of a good quality acoustic foam will mimic the natural decay found in a larger cabinet and in effect makes your bass sound 'bigger' even though it isn't. You might think you would be smitten with sonic goodness but in reality this is pretty subtle stuff, but it is additive and if you have a good ear for tone you will be well pleased with the results.

Orangeclawhammr said:
Rumble cabs are made of a type of plywood while my sub and many other bass guitar cabinets are made from MDF (medium density fiberboard). I do not know which material is more resonant or inert.
Click to expand...
A poorly designed plywood bass cabinet can be extremely resonant, making all kinds of undesirable noises at various frequencies. MDF is of course much more dense and heavy. It is a good choice for sub-woofers.

Bodeanly said:
Aren't you guys voiding your five-year warranties by taking them apart to add foam?
Click to expand...
Shhhhh! Don't Ask-Don't Tell :whistle:
 
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#7,048
Linnin said:
It should come as no surprise that a naked speaker cabinet is going to sound 'boxy'; 'wooden', and/or 'hollow' . Proper acoustic treatment eliminates that. Plus it will also break up and absorb standing sound waves and rebounding waves inside the cabinet. Ideally you want only air coming out of your ports, and not sound. All the sound should be coming from the cone(s) of your speakers. Lining your cabinet will also benefit your clarity of bottom end effectively tightening it up. Same thing for the entire mid-range especially the all important low mids where the real punch and attack lives. The absorptive qualities of a good quality acoustic foam will mimic the natural decay found in a larger cabinet and in effect makes your bass sound 'bigger' even though it isn't. You might think you would be smitten with sonic goodness but in reality this is pretty subtle stuff, but it is additive and if you have a good ear for tone you will be well pleased with the results.

A poorly designed plywood bass cabinet can be extremely resonant, making all kinds of undesirable noises at various frequencies. MDF is of course much more dense and heavy. It is a good choice for sub-woofers.


Shhhhh! Don't Ask-Don't Tell :whistle:
Click to expand...

Great info Linn :thumbsup:
 
#7,049
Linnin said:
You are welcome, JakobT. If it's past the grace period of return they may require you to go through a Fender authorized repair center. If that is the case what usually happens is Fender just sends you a brand new amp. A really good store would make the exchange and then handle the return to Fender for credit against their account. At any rate rest assured that Fender will take care of you.
Click to expand...

I bought this amp via the web, so I'm going to have to ship it back to the store so they can have a look at it. The local Fender distributor is actually in Sweden, so I can't deal with them directly. Also, I haven't kept the original packaging, so it's going to be a good deal of work packing and shipping it. Hopefully they'll sort things out relatively quickly.
 
#7,050
Orangeclawhammr said:
There's nothing to excuse. If you don't ask, how will you know?

The foam is to deaden resonances from the wooden cabinet. It is used more extensively in sealed speaker system, where it can "fool the driver into thinking it's in a bigger box" than it really is. I lined the inside of a subwoofer that I built for my home theater system. Since I did that before assembling the sub, I have no idea if it makes a difference in the sound. Also, I believe the Rumble cabs are made of a type of plywood while my sub and many other bass guitar cabinets are made from MDF (medium density fiberboard). I do not know which material is more resonant or inert.

This is hardly an expert observation, but it should help until someone who has a better idea of what they're talking about chimes in.
Click to expand...

That sounds interesting. Why wouldn't cab mfgs do this from the factory?
 
#7,053
Big Hoss said:
Q for Linnin or anyone else knowledgeable about this. I finally tested the XLR out in several months. Is the master know supposed to effect the level across the XLR? I don't remember the master changing it before but it does now.
Click to expand...
Yes, that is correct. The XRL out is post everything. Plus it goes through cabinet simulation circuity on it's way out. That way the signal sent out is as close to putting a high $$$ mic on your cab for the mere cost of a mic cable. It's a good thing. The only thing better is putting a high $$$ mic on your cab.
 
#7,056
Linnin said:
Yes, that is correct. The XRL out is post everything. Plus it goes through cabinet simulation circuity on it's way out. That way the signal sent out is as close to putting a high $$$ mic on your cab for the mere cost of a mic cable. It's a good thing.
Click to expand...

Good deal. I just don't recall the details when I used it last...
 
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#7,059
Big Hoss said:
That sounds interesting. Why wouldn't cab mfgs do this from the factory?
Click to expand...

Buzz E said:
Some do!
Click to expand...

It takes time and costs money. If you'll take a flash light and shine it through the ports of a Rumble 115 or 410, you'll see they have a white acoustic treatment inside. I am going to guess this is polyester batting such as you'd find in a comforter or inexpensive sleeping bag.
In the old days (yes I'm old) Fender used brown paper backed fiberglass house insulation for acoustic treatment. It worked.

I for one adore the acoustically engineered anechoic foams that are available. That's what they're made for.
 
#7,060
Bodeanly said:
Aren't you guys voiding your five-year warranties by taking them apart to add foam?
Click to expand...
Good point, it did cross my mind before I started. So I decided to try it out first on my 100 instead of the more expensive 500.
All I did was remove a couple of screws and put in some foam (for now with sticky tape which can be removed without any traces).
So it can be put back in factory condition with no problem.

Also, having seen the inner guts of the Rumble, I guess there is not much in it.
Either the speaker gets blown up or the amp module has a malfunction and both can be replaced easily.
 
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