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ampeg svt 4 pro question

Discussion in 'Amps and Cabs [BG]' started by ollybarclay, Dec 14, 2005.

  1. ollybarclay


    Dec 14, 2005
    is it safe to mono-bridge it into any cab? in the manual it says "ensure the cab is capable of handling the extreme output power amp is in this mode"

    can i, for example safely mono-bridge it into an ampeg 8x8 cab? or a single 4x10?

    what kinda of cab ohmage and wattage am i looking for?

  2. chaosMK


    May 26, 2005
    Albuquerque, NM
    Hi-fi into an old tube amp
    I used an SVT-4 with an 8-ohm Ampeg 4x10 cab. No problems. Of course, you cant expect an 8x10 sound out of a a 4x10 so there were limits on how hard I could push it. I usually backed off the lower frequencies a bit. If you hear the speakers farting out, back of lows or volume.
  3. ollybarclay


    Dec 14, 2005
    thanks, as you might be able to tell, i've recently gotten this head.

    used it thru a 4ohm 4x10, was pretty quiet, i had the gain at the (just below obv.) the peaking point and the master volume pretty cranked. this was using just channel a thru a speaker cable 1/4" to 1/4" jack.

    using the speakon is recommended, should i just go for it mono-bridged? given the cab ain't mine i'm loathe to do this...
  4. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    You'll surely get some headroom using it mono bridged......

    4 ohms is as low as it goes mono bridged, so you will get the full 1200W.

    As far as acceptable cabinet ratings.... that depends on so many things, how you play, how you EQ, cabinet frequency range vs your EQ and volume.... speaker cone movement limits....

    "Normally", 2 to 3 times the speaker "rating" is acceptable as amp power, maybe more. That suggests a 400W or so cabinet.

    With a speaker that isn't yours, you may feel the need to be more conservative.....

    I do know that if you use a low-power-handling cabinet with too much power, you can get some *interesting* things happening, and some ain't too good. For instance, the voice coil hitting the magnet backplate.... sounds nasty..... loud bang like like a small pistol... not good for the speakers either (don't ask how I know this).
  5. mobax

    mobax Supporting Member

    Dec 31, 2002
    New Baltimore, MI
    I mono bridged into an 8 ohm Epifani 210UL with no issues. The Epi is a 500 watt cabinet with recommended power of 200 - 1,000 watts. It is safe to use a cabinet rated for lower power as long as your expectations are within reason.
  6. theshadow2001


    Jun 17, 2004
    Its going to be safe to run the amp in mono bridge so long as you dont turn up so loud as the amp is causing distortion in the speaker. If you were getting your own cabinet I would say how many watts do you want to use. Get a cabinet that is capably of handling the wattage you need and then leave the rest of the amps power for headroom.Which is nice. a cab rated 600 to 800 watts would be good to use with the 4 pro. You could also use something rated less like 200 or 300 it would be ok too so long as your not running to loud. Ideally you would have the amp outputing constantly and cleanly the equivalent of the cabinets RMS rating.

    I dont think Im making much sense here but Im after soing to exams today and my head is fried.
  7. nickname


    Jan 22, 2005
    seeing as we're on this topic...

    if im running the SVT4-Pro (1200) into the Mesa Boogie 1516b (400W) at 4ohms, and turn the master up to the point where the limiter randomly lights up, but still have no distortion in speakers can i turn it up?

    basically i want to know if its a bad thing when the limiter lights up, even if there is no distinct distortion happening? i was under the impression taht u never want the limiter to light up, and that the gain should be turned up to the point where the led lights only when my hardest notes are hit.
  8. ollybarclay


    Dec 14, 2005
    i feel the same, having the peak LED on except when hitting the hardest notes i thought was a MAJOR no-no.

    had no problem with the limiter light coming on so far though.

    (incidentally, the show i played last night, using a 4ohm 400watt cab sounded fine)
  9. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    On the 4PRO, "peak" is one thing, and "limit" another.

    The peak light by the input can light up quite a bit with no problem. In fact, it SHOULD light sometimes if you have adequate signal and average gain set up.

    The limit light is over by the master. It isn't a problem if it lights for peaks, string pops, etc. If it's on a lot, you probably are getting the level "squashed" a bit, and are running out of power headroom.