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Ashdown ABM300 EVO -> QSC RMX2450 ->GK 410 not as loud as I expected ...help please!!

Discussion in 'Amps and Cabs [BG]' started by Femto, Jan 25, 2006.

  1. I've just got myself a QSC RMX2450 poweramp and I plan to use it with my Ashdown ABM300 EVO head.

    I've connected the Ashdown to the QSC via the "effects loop send" socket on the head to the "Channel 1 input" on the QSC.

    Now, this works and I get a wonderful sound, only, it seems to me that it's not exactly drying my clothes like I expected it to do.

    Does anyone know of a reason why I could be having problems? Is the effects send signal from the Ashdown too low?

    Okay, I'll try and answer my own question.. tell me if I'm right..

    The output level from the Ashdown's fx send socket is -10dBu but the input on the QSC is +4dBu.

    Am I just gonna have to buy myself a preamp or is there a way to get more signal into the QSC?

    Thanks all.
  2. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    That's the problem. You need a pre with adequate output level.
  3. Hmm, well here's another thought. Could I use my rack compressor (Behringer Composer Pro) to sort of "make up" the level...without introducing too much noise?

    Heh, I'm kinda clutching at straws here because I need to use the rig tomorrow for a show! :meh:
  4. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    If the Behringer has adequate gain you can, but why not just use the Ashdown's power section?
  5. Well I have been doing that for about 3 years but the band I play in is quite a loud pop-rock band and I always feel that I'm getting lost in the mix.

    We have a hard hitting drummer and the guitarist uses a 200 watt 4x12 half stack. I didn't want to have to lug another cab around so I chose to go with a poweramp instead.

    Yesterday, I tried the compressor unit and it brought the level up a huge amount. There's a little bit of hips from the horn on my cab but only when I play very softly and as soon as I dig in as much as I do when playing normally, the signal far surpasses the noise.

    I think I can live with it for now but I think I'd prefer a preamp to fit my rack.

    Would the tone of a BBE BMAX be anything like the Ashdown head's pre?
  6. dave_bass5


    May 28, 2004
    London, UK.
    Ive got a ABM300 EVOII and am looking for a power amp as well
    not decided yet as im waiting for a Schroeder 1210 to arrive first.
    In the manual it sates the output on the Effects send and tuner/line out is 0dbu and not -10dbu.
    i dont know if this is a different version or Ashdown have got the specs wrong (as they have for the EQ section) but im wondering if this would be ok for me?
    Probably going for a Crown XLS402 but not sure yet

  7. dave_bass5


    May 28, 2004
    London, UK.
    your are running the amp in bridged mode arent you?
    This would give you the most power

  8. pickles

    pickles Gold Supporting Member

    Mar 23, 2000
    Ventura, CA
    Trade off the ashdown head for an ashdown rack preamp. The effects loop is likely taken out of the circuit before the preamp's output stage, so it isn't able to drive the amp. There is also no reason to drag around a whole head when you just want to use its preamp.
  9. Actually, no I'm not. I decided that would be a bad idea as my GK cab is only rated at 400watts and I didn't wanna risk setting the poor thingy on fire, heh.:crying:

    If everyone thinks it'll be safe to do so, I'll do that but when I boost it up with my compressor unit, it's pretty damn loud. I just don't care for the hiss that I get by cranking the comp way up.

    I know I mis-spelled "hiss" somewhere in my last post - I sent that post in on my internet phone while I was at work and the predictive text caught me off guard. :rolleyes: It came out as "hips", doh!

    Also Dave, you're dead right about the FX send output. It is 0dBu - I was wrong.

    Yeah I was thinking exactly the same thing. I might go try out some different preamps and see what I like.

    The Ampeg SVP-PRO looks pretty neat and so does the BBE BMAX....although I don't know if I'm just thinking about different ones for the sake of change. I like the sound of the Ashdown anyway!! Oh dear oh dear.

    Opinions, please? :meh:

    I will probably keep the ABM300 and use it as part of a second rig as I have another cab I can put to use.
  10. 4Mal

    4Mal Supporting Member

    Jun 2, 2002
    Columbia River Gorge
    Not very likley at all. Especially if you use the sub-harmonic feature of the Ashdown...
  11. Nah, I don't use the sub-harmonizer hardly at all, only when I'm messing around just for fun. I play a 1973 Precision Bass with Seymour Duncan Quarter Pound pups in it. I play fingerstyle, quite a lot of pick and the occasional bit of rough 'n' ready slap (though I'm practicing). I like quite a lot of high mid "zing" but not so much that it gets clicky and clanky.

    Does this help anyone to suggest a preamp other than the Ashdown - just to give me a little more choices to go at...?
  12. I don't think that you should be using the effects loop for a power amp. Shouldn't you use "Preamp out" on the Ashdown to the power amp. Maybe also "power amp in"?

    Just a thought.
  13. You're dead right, Bassmanolukas. That's exactly what I'd use but unfortunately for me, my head doesn't have a preamp out socket. The only line level outputs on it are the front mounted line or tuner out and the rear mounted effects loop send socket.

    Ah well... preamps....

    Those of you who use rack based preamps, what is it, what bass do you play and what style of music do you play on it? I'm interested. :)
  14. pickles

    pickles Gold Supporting Member

    Mar 23, 2000
    Ventura, CA

    I think that ashdown pre sounds real nice ... and you already know how to work the controls.
  15. ampeg66


    Dec 29, 2002
    Who'd a thunk it, no preamp outs on the ABM EVO amps...if you like the Ashdown sound, seems like you couldn’t go wrong with getting their preamp. It’s one I’d like to try.

    If you feel your volume is adequate and proportional to the size of the rig when you use the compressor to boost the signal, I think you’ve found the problem.

    I’m curious how you use the power amp’s gain control. Don’t be afraid to crank it up if needed.

    How would I run your rig, with the current setup or with a new preamp?

    I’d turn the amp’s Limiter on, and set the Input Filter to 50Hz (if these things aren’t already set that way). Then I’d run Bridge Mono - requires a special cable - for 1300 watts (and a buttload of headroom) into 8 ohms. I’d BE CAREFUL, and pay close attention until I got comfortable with the limits of the cabinet, but I’d definitely do it. You should be able to hear when you’re getting close to doing damage to the speakers (farting, popping, distortion). But, if you, um, smell something like burning plastic, I’d shut ‘er down for a bit... ;)

    Don't know about Eden availability on your side of the pond, but if you’re looking for suggestions, I like my Navigator pre a lot.

    This is the fun part of having a rack system: you can swap out all the preamps you want until you find THE ONE. With wise purchases on used gear (eBay), you can often sell the item and break even (or close to it) if it doesn't work out. Or, if you have a good relationship with a particular shop, maybe they'd let you have an overnight test drive if they have something you're interested in.
  16. Yeah, I was rather surprised that there wasn't a pre out too.

    I think I'll see if I can demo a Navigator pre to see if I like the tone. Over here, Bass Centre stock Eden gear so I'll pay them a call and have a play around with one.

    Like you say though, I know what sound I'm gonna get from the Ashdown as I imagine the business-bits inside the pre in the ABM head and the actual rack preamp are damn similar if not identical. Plus I dig the VU meter on the Ashdown.

    As for bunging 1300watts into my 400 watt GK 4x10.... I'm a little nervous about it but I suppose if I'm careful and keep my ears and nose on full alert, I should be okay. :p

    I've been running the power amp in stereo but only one channel is turned up at present. I think that gives me somewhere between 450 and 500 watts to the GK. The gain control on the channel I'm using was set at about 2 to 3 o'clock the last time I looked.

    The limiter is switched on and the low cut is set at 30Hz but I think I'll switch that to 50Hz like you say.

    To swap it to bridge mono, I'll just have to open the speakon plug that goes into the poweramp and swap the negative wire from 1- to 2+ I think. It's all stamped on the back of the amp anyway so I'll check before I do it.

    Thanks for your suggestions ampeg66!

    Eden preamp eh....? Hmm interesting. :)

  17. Wow, that's a cool website.

    Only one problem... I've now got gas for an MTD 435, an EA iAmp 800 and a Bergie HT310. Damn you!!

    Where's the money gonna come from, that's what I wanna know!?!? :confused: :meh: Hehe.

    Yeah you're right, the Ashdown pre does sound nice. So does the Ampeg SVP-BSP. Ampeg stuff is way more expensive than Ashdown in the UK though and like you say, I know the controls of the Ashdown very well.

    Mmmmm.. Bergie HT310.. :smug:
  18. OMG I AM RIGHT ABOUT SOMETHING!!! :hyper: :hyper: :hyper:

    Well, I think that no preamp out jack means no way of using the Ash as a pre. :meh: bummer.
  19. Well, I am for now... with the help of my compressor unit.

    Oh and hey ampeg66..??? I Bridged it.

    :eek: Sweet baby Moses in his floaty floaty basket! :eek:

    It's unbelieveably powerful.
    I mean sheeeeat, our practice room is pretty cold so we have an electric heater on a timer switch that comes on every couple of hours to take the chill off the gear while we're not there....
    When I went down this evening to try the amp bridged, the heater was on.

    I slapped on the open A string with the poweramp's gain control at 11:00 and I had to switch the heater off beacuse there wasn't enough mains power for the damn poweramp AND the heater on the same double wall outlet!

    There's also a lamp with a 60 watt lightbulb on the same circuit. It dimmed quite a lot.

    No problem after I switched the heater off though. I thought the amp was fudged for a second.

    Man that thing's got headroom.

    I'm pleased.....can you tell? :eyebrow: :D
  20. ampeg66


    Dec 29, 2002
    Use your newfound power wisely, grasshopper. :D

    I can't take credit for the bridging idea - that was someone earlier in the thread - but I did think it was worth trying. I run 2400w bridged into a 1200w cabinet, it gets stupid loud and the amp’s not working very hard at all.

    Disclaimer: Be sure to take it kinda slow, the one downside to this setup is that you can definitely melt stuff. So can someone who borrows your rig; they may not realize that turning the volume up a bit could shoot your speakers across the room.

    One more thing you could try is to run the single channel on the amp, but don’t be afraid of turning the power amp gain all the way up. It might give you just enough juice on smaller gigs where you may not need the full mega-power-of-doom solution.

    Glad we could help. Enjoy!