My knowledge of physics and science aren't worthy of any degree, but I've worked with the Gramma by Auralex long enough to say more than 'Dude it sounds gooder with it under my amp!'
I started to get more and more calls to play on demos and the Gramma seemed like it'd be a great home base to getting my amp setup and dialed in quickly.
If you search forums there are plenty of guys who think these are scams, truth is sure you can make your own, but Auralex made a quality product and for $50 I think it's worth every penny.
Today more and more bands are doing the DIY recording. Maybe you're going record in your friends basement or garage and chances are it is not acoustically treated. Sitting your amp on top of the Gramma will cancel out some of the room sound and give you more amp sound and less room.
There is a handle on the bottom that makes it easy to carry. I still keep the factory box to store it in just to keep it nice.
They make a few models and the Gramma is borderline too small for a 4x12 guitar cab. This is suited more for single speaker combos.
Heavy duty. It is supposed to be able to handle 300 pounds. At 180 pounds I stomped on it and it showed no signs of giving out.
Quit letting the room stand in front of your amp's tone, let your amp talk!
This is a pad that can isolate a guitar amp from vibrating throughout the room. There are other ways of doing this, like using chairs and stuff, but those are still technically flawed. Isolating the amp so that it rings throughout the room without touching the floor is an ideal way to get a good sound. Vibrations in the floor can limit the tone significantly and really muddy up the low end of your signal. Therefore it is good to have some sort of separation from the floor so that you can prevent this from happening.
I think that this is one of the cooler things you can buy to help get a better sound. It's really cheap and it'll do a lot to prevent uncessesary loss of signal. Listening with this will give your sound more low end clarity and less unnatural resonance, both of which are beneficial to sound. Another good thing about it is it opens up new spots in the room to put an amplifier. It'll allow you to get closer to spots that would vibrate when the amp is placed on the floor, places that were thus unavailable before. This opens up room micing opportunities a lot.
I would say that it's functionality is pretty limited, but it's also a pretty cheap piece of material. If you don't have a good sounding room already, you're probably not going to benefit much from this piece of gear. However, if you own a studio and you want to get better sounds out of your amplifiers, I think that this would probably be a fine choice and it wouldn't be too enormous of a purchase. It's one of those things that you wouldn't necessarily need but can definitely improve your sound.
I used it a few hours at home.
This is my first of its kind
good quality foam product recognized
My two amps guitars sound like never before, I thought c'ètait a marketing stunt, I was amazed by the quality of reproduction of the qualities of my hp, flawless sound system, thus making clear that his fruitful.
So, I'm going to buy the mopad for monitors;
An empirical convinced
I did not write one day notice on a board with two foam blocks.
But after putting my guitar amp above, which sits in the same place a few years now, I took quite a slap.
My Boogie has incredibly gained definition, especially in the bass.
Side neighbors, they do not even give me their opinion.