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Just joined the pre/power club in a very round about way... and need some advice

Discussion in 'Amps and Cabs [BG]' started by funkmuffin, Sep 21, 2004.


  1. funkmuffin

    funkmuffin

    Aug 18, 2004
    Akron, Ohio
    So I'm sorta stuck with having to send in my Carvin R600 for service, which means I'm out of rigs for about a month. I decided to try and find some sort of beat up head to drive my rig (Carvin RL6815 combo, minus the head).

    Local "Musicians Bargain Basement" had 2 GK's I thought were over priced, and nothing else of any interest. I decided to check out the PA room and they were just testing the newest addition, an Inter M M700 (350 watts a side) for a great price.

    So I figure I've got a Sansamp BDDI, and I'll just rig em up until the Carvin gets back. Anyone using just the BDDI for a preamp? What's a little weird is that the Carvin combo is biamped, so it's like two cab's in one. An 8 ohm 2X8 up top, and a 4 ohm 15 on the bottom. I'll need to run each channel of the amp to one of the "cab's", and that means each channel of the amp needs its own input. The BDDI has two outputs, an XLR and a 1/4". Will I see any mismatch issues between the two?

    One more quick one -- anyone have any experience using the InterM amps for bass? This one happens to be REALLY clean for a used power amp -- it looked brand spankin new.
     
  2. si-fidelity

    si-fidelity

    Apr 13, 2004
    Australia
    I read up a little on the R600 from an ad in Bass player, but I've never used the SansAmp BDDI or InterM power amps.

    The problem I see with you using the power amp is that the R600's speakers are designed for true bi-amping; ie. they rely on an external crossover (unlike trad cabs with a woofer and tweeter, which rely on passive internal crossovers). This would mean that if you wanted to take full advantage of the bi-amping capabilities, you would have to also purchase/hire a 2-way crossover with your power amp. That is: signal from your bass to the SanaAmp pre, then to the crossover, then one "high" and one "low" signal into each side of the power amp and finally into the speakers.

    Of course, you could run in mono/Full range, however you'll need to dig up the specs on the speakers- more specifically the 8" cones. I'm guessing that Carvin picked the speaker configuration especially for use with that head. What I'm concerned with is that the 8" cones may not be able to handle all the low frequencies and burn out or they may be able to handle them, however could be damaged (crease or tear) by the power of the InterM power amp. To figure this out, you'd need to know the speakers RMS rating and Ohm as well as the Power Amp's RMS rating and Ohm. Your tweeter most likely is wired traditionally with the speakers (I'd be guessing the 8"s) with an internal crossover. Using one side of the external power amp may overload the tweeter as well.

    There's a lot of things that might go wrong. But if you get a wiring diagram of the speakers and all their specs along with the amps, the guys at the store should be able to advise you.

    What I'd reccommend is hiring some gear- something that's not the world's greatest rig, but passable to your ear. like a head with a 4x10" or 1x 15". Or buying a cheap/used combo/half rig (behringer make loud gear) 1x15" or 2x10" that you could later use as a practice and/or spare amp.
     
  3. funkmuffin

    funkmuffin

    Aug 18, 2004
    Akron, Ohio
    Thanks si-fidelity... Not to worry about the power handling capabilities of the Carvin stuff -- I called and spoke to their support. The 8's can handle 400 watts, and will get ~220 max, and the 15 is a 600 watt driver which will get 350.

    As to the full-range vs. biamp question -- the R600 is switchable between biamp and full-range, and I've run it full-range on occaision with no ill effects.

    I also figured out that the power amp has a "parallel" mode, which will feed a single input signal to both power sections, which will retain individual volume control, so I don't have to bother with two outs from the Sansamp.
     
  4. BillyB_from_LZ

    BillyB_from_LZ Supporting Member

    Sep 7, 2000
    Chicago
    The only question that you'll have to answer...and you'll know after trying the set-up out is whether the BDDI has enough gain to drive the power amp to full output...or at least enough output to serve the purpose.

    I believe that Cavin posts the specifications of all of their speakers on www.carvin.com IIRC the complete specs are somewhat hidden...there's a link somewhere for the Thiele-Small parameters of the raw speakers that they offer.

    Have fun!!!