Psst... Ready to join TalkBass and start posting, make new friends, sell your gear, and more?  Register your free account in 30 seconds.

Amp wattage and cabinet efficiency

Discussion in 'Amps and Cabs [BG]' started by Steve S, Feb 4, 2005.


  1. Steve S

    Steve S

    Jul 26, 2000
    Does the wattage of an amp affect how the speakers operate? I have the WT 550 which gives 500 watts into 4 ohms. When I use it with my Avatar 4 ohm CB 112, I can turn the amp up very loudly with no speaker distortion. When I use it with my HT and EX 112 cabs, I find that I cannot turn the Eden up as loud as with the Avatar and that the sound begins to get harsh and break up. The Avatar is rated at 500 watts while the Bergies are 300 watts each.

    I play a Fender Jazz Deluxe.
     
  2. How do you have it hooked up? Are the Bergs cabled together or do you have a speaker cable going to each Berg from both sides of the Eden? Do you have it bridged? I can't remember how my Eden WT800 was... I think it had two outputs at 4ohms each.. ?
    The Bergs should be able to take a huge amount of power. Sounds like you clipping the signal somehow. I've heard the WT550 is a whoopin' little package and If I'm not mistaken others here on the site use the same combination.

    Also, give Jim Bergantino a call you'll be glad you did.
     
  3. Steve S

    Steve S

    Jul 26, 2000
    Big String,

    I had each Berg plugged into the input jacks of the Eden. I have read tons of information from other bassist on this web about the efficiency of the Eden so was surprised when the speakers started breaking up when I turned up the amp. The Avatar sounds bigger and louder than both of the Bergs played together.
     
  4. AlembicBob

    AlembicBob

    Dec 28, 2004
    MA, US
    The WT550 is a mono amp, so no bridging necessary. If the Bergantinos are rated at 8 ohms, then plugging into the pair should be the same to the head as plugging into the single 4 ohm Avatar. If they are 4 ohm cabs, then the WT550 is pushing 2 ohms, which it is rated for, so there still shouldn't be any problem.

    Still, you can play with things like plugging one cab into the head and daisy-chaining the cabs off each other to see if the head has a bad jack. Are you using the same cable for both tests? If so, did you try both cables with the Avatar to rule that out? How does it sound if you only hook up one of the Bergantinos, does either sound good on its own? Do you have another amp that you can plug into the equation to make sure the cabs are okay?

    And, one of the first questions that must always be asked in troubleshooting... Did it ever work well? If so, what changed?
     
  5. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    Chances are excursion is the problem. The Avatar may well use a long throw driver while the other cabs probably don't. When you do get distortion it's usually because the driver is being pushed past its excursion limit, and that has little to do with either power handling or sensitivity.
     
  6. Steve S

    Steve S

    Jul 26, 2000
    AlembicBob,

    I've used the same cables with the Avatar and the Bergantinos. Each Berg, on its own, sounds great as they do when they are used together. It's just surprising that the Avatar is louder, deeper, much more punchy than both of them together. I've used both cabs in gigs and the Avatar is way louder so I've been using it more. At a gig two weeks ago, our guitar player kept asking me to turn up the Bergs but the output light kept flashing on the Eden then the speakers would sound distorted. Last weekend, I used the Avatar and had no problem turning it up with no distortion.

    Billfitzmaurice, that's what it sounds like....the Berg speakers being pushed too hard.

    The Begs cost almost $1000 while the Avatar was $180...
     
  7. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    sounds like it is an excursion issue. i'm unsure what the sensitivity ratings are for the bergs and the avatar.

    any chance you're boosting a lot of bass? the avatar may use a speaker with a higher xmax and be able to handle that while the bergies might be better suited to running flat. i've heard bergies get stupid loud. try not boosting (or even cutting) the bass. also, the enhance knob boosts bass (among other things) the enhance is "flat" when fully counter clockwise. having it up at "12 o'clock" may eb giving you issues as well.
     
  8. Steve S

    Steve S

    Jul 26, 2000
    I emailed Jim Bergantino and he suggested that I try a test with a 9 volt battery to see if the cables are ok or if the speakers are out of phase. I'll give it a try tonite.

    I'll also try to cut the bass and the enhance knob too.
     
  9. I am also suspicious about the relative phase of your speakers. When you plug both cabinets in, do you have less bass than only one? If so, one is out of phase.
     
  10. alexclaber

    alexclaber Commercial User

    Jun 19, 2001
    Brighton, UK
    Director - Barefaced Ltd
    If the output light is flashing on the Eden (assuming that's a clipping indicator - what else could it be?) then the problem lies not with the Bergs being pushed to hard (and I seriously doubt that the much revered Bergs have less total air displacement capacity then a single Avatar 12") but with the Eden not having enough power to push the Bergs hard enough.

    i.e. the Avatar cab is more efficient so the Eden has enough power to drive it loud enough, whilst the Bergs are less efficient (i.e. fewer dB@1W1m) so the Eden is simply running out of power, clipping, and thus making distorted farting noises. If you want the Bergs to sing at their maximum volume level (which I'm sure will be louder than the Avatar's max) then you'll need to give them more power.

    Try renting a PA-style power amp with plenty of power (1000W+ bridged at 4 ohms) and see how the Bergs get on with that, then you'll know for sure.

    Alex
     
  11. AlembicBob

    AlembicBob

    Dec 28, 2004
    MA, US
    Phase does sound like a promising direction at this point. If there is a phase problem, it could be in the cabinet, cables, or amplifier output jacks.

    Good luck!
     
  12. Steve S

    Steve S

    Jul 26, 2000
    Alex's comments seems to describe it. The speakers look like they are in phase....The Eden seems to be running out of power...
     
  13. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    That also would be a possible indication of inadequate excursion. After the driver reaches maximum excursion more power applied will not result in more volume out, it will just be dissipated as heat. Enough additional power will be heard as distortion, both driver and amp sourced. If you checked what drivers are in the respective cabs safe bet you'd find that those in the Avatars use a longer throw model than the Bergs.
     
  14. IvanMike

    IvanMike Player Characters fear me... Staff Member Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    i second what bill is going after. the little bergies dont have a ton of low end and if you try to make them produce it by boosting lows or the enhance knob past 9 o'clock they will not be happy. i've found a pair to be devestatingly loud with a 400 watt amp (in the store and watching other players use them at gigs), but you won't get them to reach their full potential if you try to fill them with the last ocatave or so al la EQ.
     
  15. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    Avatar long-throw? Far from it. Knowing what I do about the Delta12LF's used in the Avatars, I'd be very surprised if the Berg's are exceeding excursion limits before the Avatar is.

    I'm almost certain they're out of phase. I know you've done the 9v battery test but are you sure you didn't accidentally flip the battery over without realising? I've made this same mistake many times before, as have a lot of people.
     
  16. Steve S

    Steve S

    Jul 26, 2000
    Petebass,

    I double checked the battery to make sure that I'm doing this right...the speakers are in phase. Maybe I need to use less bass boost.