bass boom

Discussion in 'Amps and Cabs [BG]' started by K Dubbs, Nov 4, 2003.

  1. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    What creates the bass-boom effect that is sometimes heard when playing at loud volumes? The effect I'm referring to is where low end loses definition and low frequencies sound more like wah wah wah wah rather than sharp and intelligable.

    Is this the effect of group delay gone wild, low damping power amplification, room acoustics? Perhaps it is an unavoidable phoenominon with cabinets that produce loud bottom end?


  2. rickbass

    rickbass Supporting Member

    Have you tried a compressor ??? Compression is considered essential by so many bassists.

    If not, what is does, put simplistically, is limit dynamic range.

    A compressor tyically makes a bass sound punchier by evening out the the bass notes so each seem to reach the audience at about the same time, instead of booming low notes that sort of boom in the back of house while higher ot stay in the front rows.
  3. jdombrow

    jdombrow Supporting Member

    Jan 16, 2002
    Colorado Springs, CO
    You could also try turning down the bass control so you're not producing as much low bass. This should give you a cleaner sound.

    You might also try de-coupling the cabinet from the stage with an Auralex Gramma pad or something similar.
  4. ihixulu

    ihixulu Supporting Member

    Mar 31, 2000
    getting warmer
    I think what is happening is that the bass frequencies, which are omnidirectional, are bouncing off the walls and other surfaces and reflecting back to overlap each other. Add in the various sympathetic resonances in the room and it becomes a complete mess.

    I don't think a compressor would help in such a situation as the problem is more related to room acoustics and cab placement .
  5. K Dubbs

    K Dubbs Just graduated from OSU, Go Bucks!

    Mar 16, 2002
    Toledo, Ohio
    thanks guys

    ihixulu, i think you're onto something. I was figuring that it was happening because of something like this. If concert halls were all shaped like the resonance-damping 1x1.6x2.6 dimensions, I wonder if this booming would be reduced. Or perhaps clubs need more sound absorption materials on their walls. I also keep my eq flat, so I don't think it is too likely that the problem lies with literal boosts in the low freqs.

    Also, some cabinets are referred to as being "boomy." One commonly described this way is the swr henry 8x8. I'm wondering why this cabinet would sound "boomy" when an eden 410xlt may not.
  6. nonsqtr

    nonsqtr The emperor has no clothes!

    Aug 29, 2003
    Burbank CA USA
    Let's see, I have two tidbits to chip in to this discussion.

    One is, I've gotten lots of "boom" out of the stage. My band plays this one place on a fairly regular basis, where the entire stage is like a gigantic bass port. It sounds horrible too, the boom comes in right around 100 Hz. So every time we play there, I have to bring the parametric and tweak it to the room.

    The other thing is, ported cabs will "always" have a resonance. I don't know if the Henry is ported or not, but I wouldn't be surprised (small speakers and all). Personally I'd never use an 8" speaker for bass, but YMMV (and even a 10 for that matter, seen too many of those tiny little cones flying clear across the stage, which sucks when you're in the middle of a gig and you didn't remember to bring the backup cabs that night:)
  7. ihixulu

    ihixulu Supporting Member

    Mar 31, 2000
    getting warmer
    Hey K,

    There is an art and science to designing acoustically "perfect" rooms. If you ever come to Boston, try to catch a show at Symphony Hall for an exmaple of an acoustically perfect hall. In contrast, most bars, saloons, pubs and clubs were desgned with only one thing in mind: serve beer.

    Acoustic tiling and other damping materials are one option of dealing with the problem but most bars are simply too cheap to pay up for it. The recent fire in Rhode Island happened because the bar owner used improper soundproofing...

    Try moving your cab around. I've found that some locations on suspect stages actually act as hot spots to your rig turning the whole floor into a soundboard for your low frequencies.
  8. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    The Henry is about as ported as they come - three (I think) huge ports on the front, each about 8" in diameter!

    I believe the main cause of that nasty undefined booming are room (and hollow stage) resonances and standing waves. This problem can be increased by using cabs with particularly large amounts of low end or (even worse) large humps in the low frequency response which, if you're unlucky, sometimes correspond to the room's standing wave frequencies.

    Acoustic panelling won't help with this, though properly designed bass traps can but that's not something you're likely to find outside of recording studios.