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Do I need more headroom, or am I doing something wrong?

Discussion in 'Amps and Cabs [BG]' started by My bass in your, Nov 8, 2003.


  1. My bass in your

    My bass in your

    Nov 1, 2003
    Holland
    Hey guys!

    I have a question.
    I own a solid state Ampeg SVT200T. And I have the feeling that this head clips too early. The limiter LED lights up at 50% power. The amp is 350 Watt at 4 Ohm, so that would be 175 Watt.

    My setup from PU to the Ampegs poweramp is:
    Active bass output 100%, no EQ-ing
    Into Sansamp BDDI, some minor EQ-ing
    Into the Ampegs passive input, gain at noon. (LED lights at 1 o’clock)
    Some midrange EQ
    To poweramp section

    My cabs are:
    Ashdown MAG210t…the old version: 2x10” celestions -> 200 Watt, 98 dB
    Home cooked 15” cab with a Eminence Deltalite -> 200-300 Watt, 99 dB
    Both 8 Ohm of course

    I play in 2 bands:
    A loud metal band. Both my guitar players have a Peavey 5150 (120 Watt, tubes) + Mesa/Boogie 4x12”. The drummer isn’t that loud.
    And a cover band: general Rock, 2 guitar players both with 50 watt solid state combo’s.

    I can’t see what’s wrong? With BOTH BANDS I can’t fill the room. Not really a problem for the audience, but this rig can’t monitor me on stage. Sound engineers asked me to go louder (can you imagine!). I ignored the limiter LED the other night and after half an hour I was able the barbeque on the aluminium cooling system. Do I need more headroom?

    Greetings from The Netherlands,

    - Haico
     
  2. One thing that should always be taken into consideration is that a bass players amplification should be around 4times total guitar amplification...

    For example, if you have two guitar players @120watts x 2 = 240watts x 4 = 960watts required to compete with the guitarists.

    This applies for rock at least...

    I'm not absolutly sure if your problem is the setup or the fact that you are underpowered.

    Perhaps you should connect the sansamp to a preamp input in the back of your ampeg (if available)... This will bybass the ampeg pre, but may solve your problem...
     
  3. Skip everything and just plug your bass into the amp jack, this will give you a starting point to trouble shoot your equipment!

    Then let us know what happens!

    [​IMG]
    Treena
     
  4. Hey MBIYF,

    Couple of questions:

    How are you determining the power output at the onset of limiting? The position of the master volume knob isn't a good indicator of that, if that's what you're doing. If you're running the preamp just below its clip level (from your description you are), it's entirely possible that you could get full power out of the power amp with the master at 5. This is normal.

    Have you checked to see if the cabinets are wired with the same polarity? If one of them is cross-polarity with the other, they'll work against each other. This results in a major loss of overall level. Does the rig get louder when you unplug one cab? If it does, then one of the cabs is wired backwards. You can check this with a 9V battery. Just put the 9V across the terminals (use a 1/4" cable to bare wire or something) of the first cab. Align the battery so the speakers move outward, when you touch the terminals. Then repeat for the 2nd cab.
    Make sure you use the same cable and touch the same wires to the battery. If the drivers move in opposite directions, the cabs are cross polarity.

    Of course, there's also the possiblity that there's something wrong with the amp....
     
  5. Active bass into passive input.

    Try the active input.

    This should help if not solve your problem.
     
  6. jondog

    jondog

    Mar 14, 2002
    NYC metro area
    Yep.
     
  7. I strongly doubt that's the trouble.. The 'active' input is just a padded version of the passive one. If he can get his pre gain up to 1:00 before the input clip light comes on, then his signal isn't too hot for the passive input.
     
  8. Yeah, if anything, putting it in the active input would make it even more quiet.

    Hm, but since I'm a computer guy, doing random things for no reason often does result in a solution...Try it anyway...
     
  9. cb56

    cb56

    Jul 2, 2000
    Central Illinois
    The SVT200T is an older model Ampeg solid state amp similar to the B2r or SVT350H except its a better sounding warmer sounding amp IMO. I used one for years with an Ampeg 410 over an Ampeg 18 cab. I did feel like I had to crank it to be heard over my loud guitar players. Of course the soundman always thought I was too loud. The limiter light on mine started lighting up at about the 2 oclock position while the pre amp clip light came on about 1 oclock position. Except of course when I used the ultra low boost. Are you using it? Actually I never worried about the limiter light lighting up. To me that was just an indication thatit was doing its job. You can always turn it off if it bothers you that much. The only other suggestion I can come up with is maybe using larger speaker cabs. 410 instead of 210. 18 instead of 15. Just a suggestion.
     
  10. Haico,

    The fact that the master volume knob is at 5 out of 10 doesn't AT ALL mean you're at 50% power. If the amp clips, you're over 100%. That's what defines clipping.

    In other words: you're underpowered, or you've got way too much bass boost set on your EQ.
     
  11. My bass in your

    My bass in your

    Nov 1, 2003
    Holland
    :cool: Aha, just what Mark Reccord said. I haven't boosted bass that much, actually,.. not at all. So, I'm underpowered,... I'm a bit happy with that, because I was already saving up for a better head. :meh: If I only had the money...

    Thank you all for the tips and tricks. I'm going to try them all out. Maybe tonight. I'll let you know.

    I'm going to check the polarity for sure, because I made the cable for the 1x15" (jack to XLR) myself, so there is a 50-50% chance that this works against me.

    Thanks again all of ya! :cool:

    I'll let you know.

    - Haico