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2 amp setup using guitar and bass amps

Discussion in 'Amps and Cabs [BG]' started by lowendpurveyor, Jul 26, 2012.

  1. I know that there are some well known bass players like John Entwistle and Chris Squire that use a setup that includes bass and guitar amps. Just wondering how they achieve that. I know that they split the signal in 2 using a high pass filter/splitter or so. Can anyonerecommend a high pass filter/splitter to me and how it would be set up? At what frequency should the signal be sent to the guitar amp? Thanks.
  2. CopperheadLXXIX


    Aug 9, 2003
    Jax, FL
    There are a few different ways to achieve this:

    One way (and how I do it) is to wire your bass in "stereo" to where each pickup goes to a different amp, with the bridge pickup normally going to the guitar amp.

    You could also get an aby box and split the signal that way.

    Finally, you could use a crossover. There are a lot of rack versions, but not a lot available as far as in pedal format.

    As for frequency, I find that just so long as you do a fair cut of everything below roughly 80-100hz going into the guitar amp, you shouldn't need to worry about harming the speaker, even at higher volumes.
    scf4003 likes this.
  3. ulynch

    ulynch Supporting Member

    Nov 8, 2010
    Nor Cal
    On the cheap, try a Boss LS-2 Line Selector, and a GEB-7 bass EQ pedal. Split the signal with the LS-2, and run one full range signal to your bass amp. Run the other signal to the GEB-7, and use it to cut all frequencies below x Hz. Adjust to taste. I bottomed out the last two sliders when I did this. This cuts everything from 120Hz and below. Run this to the guitar amp, and overdrive to taste.

    "Bi-amping" like this isn't really necessary, but preserves headroom in the guitar amp by not sending it the low frequency signals that don't generally sound great distorted. YMMV. You might like it running both amps full range.
    scf4003 likes this.
  4. will33


    May 22, 2006
    Where to cross over is a matter of personal tone taste, guitar speaker is OK with anything over about 200-300hz as far as cone excursion goes. May still be some power demand issues on the voice coil if it's a single lower power guitar speaker.

    Most crossovers operate at line level, so a lineout from the bass amp with the low side of the crossover patched back into the effects return/power amp in of the bass amp. The mid/high guitar amp can get more flavor going in the front end and using it's preamp and eq. There, I've set the high out level of the crossover way low before so I can still go in the front of the guitar amp and get it's whole tone. Just patching in it's power section gives you power tube grind at a certain volume level and not as much tonal flexibility. It pretty much just becomes a slave amp.

    Another way is the "poorman's biamp", which means just run your whole bass signal into both amps via a splitter or something and dump the bass knob on the guitar amp and the mid/high controls on the bass amp. Not a true signal splitting crossover, but sounds pretty good.
  5. Johnny Crab

    Johnny Crab ACME,QSC,Fame/Hondo/Greco/HELIX user & BOSE Abuser Gold Supporting Member

    Feb 11, 2004
    South Texas
    The poorman's biamp can also be done using the MXR 10 band EQ stompbox(accepts any signal from instrument to line level). I use one to kill lows when we play large stages with good FOH and monitors to feed a Behringer kickback for mids and highs.
  6. will33


    May 22, 2006
    That's another way to get it done.

    Main idea is, whatever you have to do to get the lows out of the guitar rig, and preferably, the clean upper mids and highs out of the bass rig so you have big clean lows and guitar distorted mids highs coming together in front of the rig. Any weird sound anomalies will be in the middle range where the 2 overlap. The true crossover helps separate them a lot more, but the other ways can sound damn good too.

    @ JohnnyCrab-- we moved in April and I still haven't hooked up a TV. I can't even stand them now if I walk into some place where one is on. That whole feeling of that box and the people in it blabbing at you and telling you "this is really what happened and this is what you shoukd think about it" is totally disgusting. The sitcoms are geared towards the slowest minds out there. Yes, I believe it really is to dumb us all down. All you have to do is not watch it for a bit to see that as in-your-face obvious. Doesn't take long at all.

    wildman2 likes this.
  7. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    A driven guitar valve amp compresses and high pass filters enough on its own to not be blowing guitar cabs with reasonable handling. You don't need much power if the lows are covered elsewhere. You can have a mess in the midrange, it sounds good and dense.
    scf4003 likes this.
  8. So a lesson for anyone who doesn't know.

    Biamping = Sending a signal thru to a splitter/crossover where you separate high and low signals at a certain frequency (Woofer deep/Tweeter gritty)

    Stereo = Simply splitting your signal with your full range on both signals for differing tones on each (Rickenbacker neck pickup clean, bridge dirty)

    Entwistle did biamping (mostly)
    Squire did stereo
  9. will33


    May 22, 2006
    This is a good distinction to make as the terms get used rather loosely sometimes.

    Biamping obviously translates to "2 amps" but it doesn't stop there. You need a frequency split with separate amps and speakers handling each.

    Stereo also needs 2 amps, but it isn't the same as the "stereo" split on your home stereo/record player, etc. Real stereo actually sucks live. At least 2/3rds of the audience gets crap sound with one side blasting their heads off and completely missing out on the other channel. That narrow strip of people down the center of the audience are the only ones who get anything approaching decent sound quality.
  10. TheOriginalName


    May 28, 2018
    How do you wire your bass for “stereo”? Do you use one of those signal splitter dodads? Sorry, a bit new to bass.
  11. The member you are addressing last logged in on March 17 2017.

    The usual method is to replace the basses output jack with a TRS. Wire the bridge pickup to ground, sleeve and the tip and the neck to ground and the ring.
    Kriegs likes this.
  12. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Mine just has a separate output and volume for each pickup, using a TRS jack.

    It isn't really stereo though, dual mono.
  13. PullThePlug


    Jan 8, 2014

    I used to use a bass and guitar amp for my rig when I played in extreme metal bands.

    I found that using a crossover to split the two signals was not satisfying.

    Instead, I used an MXR A/B Box, and ran my signal full range to both amps. I used the onboard amp EQs to get the sound I want. MUCH fuller than using a crossover.

    Strong cut to bass on the guitar EQ, and adjust bass to taste on the bass EQ.

    It was GLORIOUS.

    I was using a Genz Benz NeoX212T and a Genz Benz G-Flex 212 - with an SWR SM900 and Peavey Ultra 60.
  14. TheOriginalName


    May 28, 2018
    What is a TRS?
  15. Tip, Ring, Sleeve. :)
  16. Mr. Foxen

    Mr. Foxen Commercial User

    Jul 24, 2009
    Bristol, UK
    Amp tinkerer at Ampstack
    Stereo type jack. Looks like those jobs for embiggening that come with proper headphones.

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