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Lack of low end - Auralex Gramma solution??

Discussion in 'Amps and Cabs [BG]' started by Mattbass97, Aug 20, 2016.

  1. Mattbass97


    Apr 9, 2011

    I was wondering if you could help me sort out a problem I have.

    I have a fender rumble 350 and it has served me well, most recently at a gig for Legally Blonde the musical.

    Anyway when I use this amp in my bedroom which is on the second floor the low end seems to completely disappear leaving me with not so pleasant mid range which I have to cut.

    Would a gramma help isolate my amp and provide me with more low end instead of it being absorbed into the floor etc?

  2. Rick James

    Rick James

    Feb 24, 2007
    New Jersey
    Your lows aren't absorbed into the floor. That's acoustically impossible. They're probably being cancelled out by room reflections off the walls.
    Isolation devices don't do what they claim.
    Testing Loudspeaker Isolation Products
    Coolhandjjl, seamonkey and Sid Fang like this.
  3. Mattbass97


    Apr 9, 2011
    Thank you, I'll give that a read.
  4. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    The pad helps if your floor is spongy. I like mine.

    Try an experiment. Raise the cabinet off the floor closer to ear level. This will allow you to monitor better.
    jnewmark likes this.
  5. Passinwind

    Passinwind I know nothing. Supporting Member Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    I have a couple and have found them quite helpful in certain specific cases. Auralex have some before and after sound samples here. The general idea is to kill boom, not to increase low bass output though.
    Al Kraft and beans-on-toast like this.
  6. bucephylus

    bucephylus Supporting Member Commercial User

    Aug 18, 2002
    General Manager TecPadz LLC
    While I understand and agree with what you are probably intending to say here, your statement is overly broad for no good purpose. We agree that lows are not improved per se, etc; however, not all makers of isolation products make that claim. So, asserting such is inaccurate and misleading. The devices make no claims, they just do what they do.

    The actual role of isolation devices is to isolate. There are cases where that function is appropriate and useful, even though that may be limited, and in your particular case, not needed. It is fine to refute incorrect claims; but, going past that begins to sound subjectively questionable.
  7. bucephylus

    bucephylus Supporting Member Commercial User

    Aug 18, 2002
    General Manager TecPadz LLC
    As other posters have suggested, cab coupling may or may not be your problem. There is a relatively simple way to find out before you go spend money on a designed isolation device. Get some inexpensive gardening kneeling pads at WalMart, about $5 each, and put them under your cab. Then see whether or not it addresses what you are hearing. If not, then you did the experiment and aren't out a bunch of cash. If so, then you can figure out what isolation device works best for you.
    Last edited: Aug 20, 2016
    Al Kraft likes this.
  8. hondo4life


    Feb 29, 2016

    That test is awfully fancy.
    Sound quality aside, the little foam pads that came with my Mackie CR3s are enough to keep my heavy wooden computer desk from vibrating. Without foam, the right music could massage away carpal tunnel symptoms.
  9. If your Rumble is the 2x10 model, try standing the amp on it’s side so the woofers are vertical. I suggested this to the host bassist at a jam I went to and he loved the difference it made. YMMV
  10. seamonkey


    Aug 6, 2004
    If the speakers sound better with a gramma pad then there's something wrong with the speaker. Usually cheap or no bracing.
    I would not expect Fender has such a problem.
  11. noagreement


    Oct 12, 2006
    Yo Philly!
    Same as the others, and certainly nothing against Auralex, but try some inexpensive options. I used to get ridiculous boominess (way out of control) at a local club with wood parquet floors, and had looked at those pads as a solution. But I tried two simple pieces of hardwood strips underneath my Aguilar cabs (less than 1" lift total) and the cabs immediately sounded beautiful. Since then, those two pieces of wood are in my truck at all times.
  12. Mattbass97


    Apr 9, 2011
    Thank you for everyone's input! I'll take it all into consideration. The amp when placed on a solid floor sounds brilliant so it's not its fault so to speak its more the room I'm practicing in.
  13. someguyfromNC


    Jul 4, 2015
    I use mine on hollow stages with great results. It wont add low end. Just help the boomyness in VERY specific situations. A milk crate or a chair would give the same results.
    jnewmark and ExaltBass like this.
  14. one of those can be useful to prevent too much bass going into the floor below, but won't give you nay more lows in your room
  15. Rick James

    Rick James

    Feb 24, 2007
    New Jersey
    Products labeled as acoustic isolation devices, including but not limited to Auralex pads and SVS 'magic feet', claim to do what cannot be done. You don't call your devices acoustic isolation devices, and you don't claim that they can do the impossible, so there's no need to get your panties in a bunch every time the snake oil brands get called out for their shenanigans. IMO if you don't want to seem guilty by association with them you should disassociate yourself from them, including not saying what could be misconstrued as defense of them.
    It can't. Bass transmission isn't interrupted by a piece of foam. It's not even stopped by concrete, because bass wavelengths upwards of ten feet long will just go around anything under the cab, unless whatever you put under the cab covers the entire floor. This is basic simple acoustic engineering fact, which every student of acoustics learns in their first semester. But I doubt that encompasses even 1/100 of 1% of the population, bass players included. It's their customers total lack of understanding of how sound waves work that keeps acoustic isolation device makers in business.
  16. bucephylus

    bucephylus Supporting Member Commercial User

    Aug 18, 2002
    General Manager TecPadz LLC
    I'm just curious why you seem to feel the need to be so provocative about this topic? Wouldn't an intelligent and respectful discussion be more useful? We are all bass players. We are all up against similar problems to work out.

    There are actually two physical effects going on as the cab projects sound.

    First, sound waves are being projected into the air via the motion of the driver. We agree that those sound waves are not influenced by isolation devices placed beneath the cabinet. Let's please not waste time arguing that point.

    Second, the cabinets vibrate. The reason for this is Newton's second law. The driver motion is decelerated and accelerated during each waveform. Two responses happen within the cabinet that support this motion. One is a direct action/reaction by the cabinet to the driver motion. The other is an action/reaction by the cabinet to pressure fluctuations within the cabinet. The external response of the cabinet to these forces is vibrations. Those vibrations can be transmitted either into whatever platform or floor upon which the cabinet is placed or to items, such as amplifiers etc, placed on top of the amplifier.

    The latter behavior is the the effect that vibration isolation devices are designed to substantially reduce.

    I don't see this as a big deal, and certainly not a big enough deal to get personally cross wise between us on a public discussion board. Discussions about the effects are fine. I just ask that we please be nice about it.
  17. seamonkey


    Aug 6, 2004
    Low bass is omni directional. It's going to wrap around a cabinet and shake nearby things up no matter what isolation you put around the cab.

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