Bass stacks and crossovers

Discussion in 'Amps and Cabs [BG]' started by coully, Jul 23, 2009.

  1. coully


    Jul 20, 2009
    At risk of sounding naive, I have a question about using speakers of different sizes in a stack (say 1x15 and 4x8 as an example).

    If in a PA you would use an active crossover to direct the sound to the most appropriate speaker (bass/mid/high to the appropriate box) why would you not do this in a bass rig??

    Speakers with tweeters or HF compression drivers normally have a crossover network internally but with separate speakers the rule seems to be to drive them with exactly the same frequency range regardless.

    Has anyone experimented with doing this and if so, what were the benefits or drawbacks? How did you set the rig up?

    Are there pre-amps or amps which support this kind of approach?

    Thanks in advance :meh:
  2. nixdad


    Aug 15, 2008
    Los Angeles, CA
    Coully -
    If you're using a 1x15 and a 4x8, you will be running the rig "full range." This basically means that no crossover is involved, that the individual characteristics of the speakers and the cabinet design (along with the amp and your bass) will contribute to the overall tone. You'll find that running full range is most beneficial in most rooms, and that it also sounds better with most bands.

    The pitfalls you need to understand if you run a bi-amped rig is that although the separated tones of the top and the bottom may sound great when you're playing by yourself (and especially for slap & pop,) the issue is that in many rooms those tones will not cut through the mix. The bottom will be in the frequency range of the kick drum, and the top will be in the frequency range of the guitars - you will be lost in the mix. Bass actually cuts through best in most rooms in the mid-lows - not the honky, annoying midrange, but in the low kick-you in-the-chest area. Bi-amped rigs with crossovers (1x18 & 2x10 cabs were common) were VERY popular in the 80's, but most guys (including yours truly) went back to full range rigs. The few guys that you will typically see using bi-amped rigs these days are in pro bands on BIG stages where they have all frequencies covered. Full range rigs are easy to set up and very easy to manage - just plug and play.
  3. mrtn400


    Dec 6, 2008
    People use active crossovers in bass rigs for the same reason as they're used in PAs.

    You get to bi-amp (or tri-amp, quad-amp, dodeca-amp if you want to be an ass ;)) your speakers to run a certain range of frequencies to certain speakers, without having to resort to power-wasting passive crossovers.

    Basically, so you're not running 20k into an 18", and 60Hz into a 1" compression driver.
  4. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Look at the fEarful threads and the earlier Carvin LS 1503 ones for examples of bassists taking the approach you're talking about. Old school biamping with say a 115 and a 410 generally worked poorly, but something like a 15/6/1 combination lends itself well to multiamping.