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Acmes and the ol' Bass Boost...

Discussion in 'Amps and Cabs [BG]' started by jokerjkny, Mar 29, 2005.

  1. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    hey all,

    i was thinking about some aspects of my Aguilar DB680 / Acme rig, and while looking over my old Acme manual, and in one section, andy says,

    my question is...

    if i use the "+" or "++" boost on my Aguilar DB680, which adds about 3 dB or 8 dB of boost respectively at 30Hz, will i be hurting my Acme cabs?

    with either of these settings, i'm thinking i'll reach a more approximate "flatter", truer bass tone at lower volumes. could be a great way of fatten up my sound for those really low key gigs. but do you guys think i'll be hurting my speakers??
  2. dood


    Dec 9, 2004
    Hmmm... My thoughts would be that you will be fine at lower volumes. As long as the cones isn't thrashing backwards and forwards then I think you are pretty much safe. I would liken it to a gate swinging madly in the wind. That could break it.. If you could 'turn the wind down' (the amp volume) then the gate is gonna swing less and cause less damage.

    Am I on the right track, all you technical types?
  3. I'd call Andy if I were you. Also, try to find out more about what that EQ boost really does. Often, when you boost the EQ at a specified frequency, you're also boosting frequencies some distance above and below that frequency. So it would help to find out how "wide" the boosted band is (IIRC, this is "Q"). In a perfect world, you'd probably want to boost between about 31 and 38 (I think that's where the -3 point is?), but not significantly below 30-31.
  4. tombowlus

    tombowlus If it sounds good, it is good Gold Supporting Member

    Apr 3, 2003
    Fremont, Ohio
    Editor-in-Chief, Bass Gear Magazine
    I have found that my ACME cabs need less bass boost than any of my other cabs (which is nice), but that they also tend to not like me to use much, if any, bass boost on my OBP-1 (or 659 or 680).

    If you talk to Andy (or Dave), I would, of course, be interested in hearing what they have to say. My thoughts, as always, are proceed with caution, and let your ears tell you when too much is too much!

  5. Boosting bass eq is much the same as turning up the master on a bass amp because most of the power is used on the low frequencies.
    +3dB is double the watts. If (for example) your amp is running at 300w and you dial in another 3dB of bass, it will be trying to push 600w. Does it have that much in reserve? If not, it will clip and that's what takes out the speakers.
    +6dB is 4x the watts, so +8dB must be around 6x.
    I'd be more concerned about whether the power amp has enough clean headroom than about the speakers' power handling.
  6. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    I often boost the bass using the onboard EQ on my OBP-3 equipped Warwick. It is possible to upset the speakers but you can hear them complaining long before any damage occurs.

    And when I say boost, I mean sometimes as much as most of the way up on a knob that is +18dB @ 40Hz. Of course, I'm usually lightening up my touch to go with the reggae tone it generates so the increase in volume is not crazy.

  7. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    thx for your help, guys...

    so, i guess i should just use my ears, and listen for any craziness.

    i thought that if i had been using the bass boost, i'd still be doing unseen / unheard damage, despite the tone being soooooooooooooo good. :smug:
  8. tombowlus

    tombowlus If it sounds good, it is good Gold Supporting Member

    Apr 3, 2003
    Fremont, Ohio
    Editor-in-Chief, Bass Gear Magazine
    Well, Andy would of course have the final word on this, but I would think that if the tone sounds great, and you cannot hear the speakers stressing out at all, you should be fine.
  9. Lonnybass

    Lonnybass Supporting Member

    Jul 19, 2000
    San Diego
    Endorsing Artist: Pedulla Basses

    I think you'll be ok as long as you watch your volume level VERY carefully and don't push anything too hard.

  10. Doesn't matter how much you boost 30Hz and below, if there's no signal below 30Hz, there's no output below. Low B is around 27-30Hz fundamental.


    I notice sting handling and bumping the strings seems to cause lots of subsonic signals. For those I've been running a subsonic filter on my rig, that should take out the harmful parts. Fmod makes some that you can use inline for a cable. They come with RCA jacks (m and f), so you need an adapter to get to 1/4" guitar patch cable. I use 2 20Hz high pass in series, I think that ends up being a cutoff of just under 30Hz or so.

    Seems to really help knock out lots of excessive cone excursion. Without affecting the tone.

  11. jokerjkny


    Jan 19, 2002
    NY / NJ / PHL
    vedde interesting, steve...