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I blew a speaker...

Discussion in 'Amps and Cabs [BG]' started by brutalmetalguy, Feb 24, 2004.


  1. I blew a speaker in my Ampeg PR 410 HLF! Now I have natural distortion... :D It sounds great! I recommend everyone try it. All you have to do is cut a few slices in your speaker, and crank it for a while. You get this excellent sound that's just............... Okay, so I'm kidding. But I did blow a speaker, and I do need your help.

    I want to replace that speaker, of course, but not with the stock one. I want to upgrade it, and the others, as well. Can somebody tell me a good speaker upgrade for my cabinet? I was thinking Eminenance Kappa 10", but it's magnet is a whole lot heavier and it is 8 ohm. I think the stock speakers in my cabinet are 16 ohm... But I don't know. What do you guys think?

    Thanks a million!
     
  2. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    That's probably not a great idea.

    If you replace one of the 4, they will be mis-matched, and will not tend to move together. Then either the 3 will overpower the one, or the one may move more than the others. Either way, you could have speakers exceeding mechanical movement limits.

    Different speakers will produce different cone force per amp of current. If the new speaker is less powerful (lower BL product) then it might not be able to balance with the others at the same position and air pressure, and its movement could be reversed, extra stress might be put on it, or the effective system resonance might be affected (it's ported).

    If the new speaker is more powerful, it may move somewhat independently of the others, possibly exceeding its limits.

    You really ought to replace with same type, or upgrade all the speakers at once.

    Since it's a ported cabinet, if you replaced the lot you would be re-designing the system, and would need to be careful to use speakers with reasonably suitable parameters.
     
  3. I do want to replace all of the speakers with new ones.... I just don't know which speakers to choose...
     
  4. The Clap

    The Clap

    Jan 5, 2004
    Scottsdale, AZ
    It's definitely not as good of an idea as you think, and I'd advise you to just find a stock replacement. If you're really interested in customizing, read up and make your own 4x10 or 2x12 or whatever floats your boat
     
  5. Thanks for the advice, but why would it not be a good idea?
     
  6. zoran

    zoran

    May 10, 2002
    croatia
    'cause it's not PR 410 HLF anymore. Why don't you take Avatar box and made your own 4x10" as it's said before, and sell repaired ampeg?
     
  7. brutalmetalguy

    You could go for the Eminence Delta, the pressed frame, and it's available in 16 ohm. I'm not sure how the HLF is wired, whether series or parallel, so you may want to make sure before you count the Kappa's out. Either one will be a suitable upgrade to the stock Ampeg speakers IMO. Also, IMO, I think the 'HLF' of the cabinet is referring to the inside dimensions and porting, rather than with the choice of drivers used. Like many manufacturers, if Ampeg discovered that the stock drivers just went up in price for some reason, they'll buy from another supplier (cheaper) and not change their cabinets at all.

    I've replaced speakers in cabinets before, and the changes have always been the same or better, never worse.
     
  8. Thanks, Mo... I appreciate your post.
     
  9. What is and Avatar box? I'm not familiar with this.
     
  10. Avatar makes speaker cabinets, and alot of TB'ers use them because they are good and cheap. They sell empty boxes and let you fill them with whatever speakers you want. That's what he's talking about.
     
  11. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    NOPE

    If we had to change drivers to ones with different parameters, we would likely have to re-port. It's easy enough to do, so I don't know why it wouldn't be done, unless it wasn't necessary.

    Yeah, there is such a thing as economic reality, but we ARE talking about Ampeg here.................
     
  12. Saetia

    Saetia

    Mar 27, 2003
    Wisconsin
    One thing about checking out new drivers to replace blown speakers if you are not using the same kind or direct replacement is to see if it will actually work with your cab. You have to take a few things into account before you just buy new speakers and put them in there, like how much volume each speaker needs and porting. You could run into some problems if the specs on the speakers don't match up to the specs of your cab.
    peace
    -Ben
     
  13. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    BMG, let me see if I can explain this more clearly.

    Have a look at the Eminence website. You will notice that each of the speakers they sell have published "Thielle/Small parameters". Those paramaters are what cab designers use to determine the correct cabinet size and porting. Both are very important parts of speaker cab design and if you get it wrong, even great speakers can perform like garbage. There's a whole bunch of formulas and math/science involved.

    I'll take the Kappa pro 10's you were looking at as an example. The math says that each 10" needs 8.8 litres (0.31cu.feet) of cabinet volume, so 35 litres for a 4x10. You're Ampeg is probably much larger than that. Furthermore, the specs say the cab will have a frequency response which it -3dB at 155Hz. Even with 4 of them, you'll have no bottom end. It's a PA speaker.

    Now lets assume for a sec that we get lucky and we find speakers that will work in a cab the size of your Ampeg. We now have to adjust the porting. Porting is a little more complicated than just cutting a hole for air to escape. A correctly designed port actually tunes the cabinet to a certain frequency determined again by the speakers t/s parameters. So if the ampeg is tuned to say 50Hz, but the speakers you found need to be tuned to 40Hz to work properly, we have a problem. Circluar ports are easier to adjust than shelf ports, but it's a bit of a hassle either way.

    If I were you, I'd be getting the damaged speaker re-coned. Then I'd be asking questions to work out what went wrong that made the speaker blow.
     
  14. Redesign is much more like it.

    The chances of a driver with different parameters being correctly matched with the existing cabinet volume are about nil. I have yet to see ANY commercial ported cabinet that is engineered to correctly match the drivers.

    As for the blown speaker: replace it or repair it with a factory part. Do not use aftermarket recone kits, because it will no longer be an Ampeg driver.

    If you don't like them, or have a need to tweak, sell the Ampeg cabinet as stock and buy something else. Tweaking it will destroy the resale value.

    The Deltas are PA quality drivers. No matter who uses them.
     
  15. If you just had that one blown speaker re-coned would the sound still change seeing its the same motor and construction as the other 3 speakers?
     
  16. Petebass

    Petebass

    Dec 22, 2002
    QLD Australia
    That would depend on the condition of the other 3 speakers.The re-coned speaker should sound very much like it did when it was new.
     
  17. Jerrold Tiers

    Jerrold Tiers

    Nov 14, 2003
    St Louis
    Well, as the OEM, we would start by getting as close as we could......and you can bet we wouldn't be wanting to change the whole cabinet if we could avoid it (and as an OEM, we ask for what we want, and get it if it is gettable, so we could no doubt avoid changing the cab).

    I hate having to go through that, because so often a speaker ends up being a complete compromise that somehow works out right. Be forced to change one thing, the cone type, coil former material, or even the glue or the cone treatment applied, and you may face a lot of work to get back to where you were, if you even can tone-wise. But the same basic T/S parameters can usually be obtained, not that it will always help..

    Porting "correctly" is an interesting point..."correct" is when it does what you want it to. So "correct" may be flat, or just the right "bump" in response, or for best cone movement control with aceptable response, or....................(attach list here).
     
  18. I keep forgetting all the manufacturers WANT that nasty hump at 80 ~ 100 Hz and the corresponding steep rolloff below Fb that results from cramming drivers into too-small of a cabinet volume.

    Or, they WANT that sloppy mud that is inherent in an EBS design, where you need a Big Johnson just to get traction.