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Bi-amp or bridge, what would you do?

Discussion in 'Amps and Cabs [BG]' started by embrynat2000, Nov 8, 2005.

  1. Hey there all, I just found myself a trace-elliot ah500x bi-amped head from the late eighties. Pretty cool looking head,with a built in black light.

    It's biamped with two 250 watt amps and can be run 500 watt bridged as well. Previously I have just used combos for bass, though I have had a few guitar stacks. Should I use the bi-amping and get say a 410 and a 15, or go with the bridged and get an 810 or 610?
  2. getz76


    Apr 3, 2005
    Hoboken, NJ
    I'd go bridged. Bi-amping isn't really (as) necessary due to the full-range nature of modern cabinets; it's actually a waste of power.
  3. spectorbass83


    Jun 6, 2005
    Pardon my ignorance...what exactly is bi-amping?
  4. Ian Perge

    Ian Perge Supporting Member

    May 11, 2001
    Evansville, Indiana
    Oversimplifying things, it's running your signal through a crossover, splitting it into "high" and a "low" signals, amplifying them separately and sending them to dedicated cabinets. In theory it's a very efficient way of EQing the high and low signals to the best of their needs, and for effects-heavy players to run effects only to their high-end and leave the low-end clean, however...

    I absolutely agree with the above statement. I think bi-amping was a better workaround solution to inefficient speaker cabinets in the 70's and 80's, but with the release of very high quality/responsive bass cabinets in the last decade or so it seems the general consensus is that it's unnecessary, poor usage of available power, and lacking in low-mid "balls" due to the splitting of signals.

    I had a conversation with a recording/touring pro about this issue, and he had come to the same conclusion after switching from bi-amping to bridging an SWR SM-400 (with a addition power amp) into 2 Goliath IIs - each cabinet was so responsive in bridged mono that there was little use in his bi-amping.

    Granted, there are legitimate uses for bi-amping: as noted above, players running effects can avoid muddying their low-end by only effecting the high-end signal, some Gallien-Krueger amps and cabinets are wired to bi-amp their tweeter with a relatively small amount of wattage from their amps (50 watts), and some players simply like it as part of their sound. However, IMO it takes a tremendous amount of research/trial-and-error to work out the kinks for too little effective worth.
  5. Thanks for the advise, the bi-amping really seems like it would be cool, but I really wouldn't know where to start as far what cabinets would work best for me and all. The bridged option seems better to me as well,
    its funny, the trace head amps are 4 ohms each, so is it 2 ohms bridged? I have to go home and take a closer look after work.
  6. ps. any cabinet recomendations?
  7. getz76


    Apr 3, 2005
    Hoboken, NJ
    I think you have it backwards, if the amplifier is 4-ohm stereo, it would be 8-ohm bridged.
  8. Oh, I guess your right. Probably would be 8 ohms bridged. Where the hell am I gonna find an 8 ohm cab that can keep up with this sucker? It's 500 watts bridged, but I think that rating is a bit conservative. I was playing it through a 200 watt hartke 115xl that has been laying around last night, with my swr workingman combo slaved out to help the hartke a bit. The trace was on "2" and the hartke was still farting like an old lady on atkins diet.

    Maybe I could get two 4 ohm cabinets in series for a total of 8 ohms? hmmm.
    I would like to have the option of going for a 610 or an 810 though, and I haven't seen any that are 8 ohms. Or I could go back to the biamp option. Like I said, My experience with bass rigs has been combos with extension speakers thus far (I'm a guitarist transplant who found that he loves bass). This is my first big rig set up, I have some cash to spend and want to do it right with my cab setup here.
    There is also the stereo full range option, 250wattsx2 at 4 ohms, but I was having trouble getting any sound when I switched it to that setting last night.
    What do ya say there guru's?
  9. Passinwind

    Passinwind I Know Nothing Supporting Member

    An 8 ohm Schroeder 1212 will laugh at your puny 500 watts...really! :cool: Just about any cab rated at ~350 or better should do fine, actually. Take a look in the Amp forum's FAQ (How Much Power?, etc.) for more thoughts on this.

    There is also the stereo full range option, 250wattsx2 at 4 ohms, but I was having trouble getting any sound when I switched it to that setting last night.
    What do ya say there guru's?

    I was about to ask if this was an option for your amp. Try to suss getting that option working, it's a viable one for sure.
  10. Ok, On lunchbreak I went home and plugged into my new baby and fiddled about a bit. In bridge mode, both amp volume knobs on the back of the amp work, if I had the speaker plugged into channel A, i could turn the volume on that amp up or down, but the knob on channel B (with no speaker hooked to it) did not make a difference in amp volume. But when I plugged the speaker into channel B it was the opposite, the volume knob for B works, but not A. This is not how any other bridged amps have worked for me. Usually its just one channel controlling volume, with the other volume knob bypassed.
    On both channels (amps) it says 4 ohms next to the speaker output. From the way the amp is behaving as described above, could I hook 8 ohms into each side, or even 4 into each side?
    I really don't wanna blow my new head!
  11. Passinwind

    Passinwind I Know Nothing Supporting Member

    Sounds like you're in parallel (dual mono), not bridged? Is there a separate bridged output jack, or?
  12. PLUS! the stereo option is kinda weird....

    It says on the back of the amp, by the switch to choose between bridge, biamp, stereo,

    1. mono full range: (both inputs linked)
    2. mono biamp: (channel A high pass Channel B low pass)
    3. Stereo full range: (Inputs seperate; both inputs full range)

    There are line in and line outs next to the volume knob on both channels A and B (located in the rear of the head). The only way that sound comes out (in stereo mode) is when something is placed into the line in on the rear of the amp. I took my line out from the preamp and plugged into this line in in the back and got sound. (I only tried this VERY BRIEFLY, and at extremely low volume, as it seemed like kind of a dumb thing to do.)

    So what's up with that?