1. Please take 30 seconds to register your free account to remove most ads, post topics, make friends, earn reward points at our store, and more!  

Need help with speaker cab & ohms

Discussion in 'Amps and Cabs [BG]' started by ejaggers, Oct 1, 2009.


  1. ejaggers

    ejaggers Supporting Member

    Aug 18, 2009
    Fort Worth, tx
    Some of you may know, that I’ve been away from playing for years, and am trying to get back. I have an old Peavey 400 2x15 amp that sounded like crap, so I took the head to the shop. Shop man charged me 50 bucks to clean it up, and it sound fine thur his Ampeg speakers. I get home and it’s still distorted, so I’m taking it back to the shop Saturday.

    Help me out here if I need new speakers, I’m confused about ohms:
    The back of my cab says 4 ohms, but my head says 200 watts @ 2 ohms.
    I’ve seen replacement brackets for the 4 ohm speakers, and 8 ohm replacement speakers, but no 2 ohms.

    So here are my questions:
    1. The higher the ohms, the less wattage, so why would anyone use 8 ohms, and what would be different if I put them in my cab (other than watts)?
    2. How do you get to 2 ohms with this setup?
    3. The 4 ohm baskets are $110 each, so would it be better to use different speakers.

    I know I need a better amp, and will probably get one later, when I prove to myself that I’m back.
     
  2. G00D+~VIBES

    G00D+~VIBES

    Nov 21, 2008
    Kansas City
    I'll take a shot at a couple of these, but I'M NO EXPERT

    1. I think I've heard something about higher ohms having better stability when using a lot of power (this could be smoke blown into places I only touch when I shower)
    2. I know if you daisy chain two 4Ohm cabs it will yield a 2Ohm resistance

    Hope that helps...
     
  3. billfitzmaurice

    billfitzmaurice Commercial User

    Sep 15, 2004
    New Hampshire
    Owner, Bill Fitzmaurice Loudspeaker Design
    You both need to read the first post at the top of the page.
     
  4. ejaggers

    ejaggers Supporting Member

    Aug 18, 2009
    Fort Worth, tx
    billfitzmaurice,
    Seems to be that it would have taken the same amount of effort to answer the questions as to say what you did. That's assuming, by your statement, that you have answers.
     
  5. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Thousand Oaks, CA
    John K Custom Basses
    Bill didn't say that to be insulting. he efficiently pointed you to where you could get the most help. and yes, he can answer more questions about speakers than you'll probably ever have.
     
  6. Jazzman

    Jazzman

    Nov 26, 2002
    Raleigh, NC
    Bill was trying to save you time - the answers to your questions are already given in the FAQ.
     
  7. ejaggers

    ejaggers Supporting Member

    Aug 18, 2009
    Fort Worth, tx
    I wasn't insulted, I'm just looking for answers. Trust me, I'm not that sensitive. And I did look where he said to look, but haven't found the answers yet. There's alot there.
     
  8. IvanMike

    IvanMike Player Characters fear me... Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    in the sticky check out my ohms thread.

    fwiw, there is negligible sound degredation @ 2 ohms on a 2 ohms stable amp. sure you can find it on a scope, but i've done it a bazillion times and i've never heard it.

    you prolly nead new speakers. get the replacements for yoru cab as they are all made different. DON'T make it a 2 ohm cab by adding 4 ohm drivers. you will regret it the first time you buy or need to borrow a head that is only 4 ohms stable.

    FWIW, you can get a 2 ohm load with four 8 ohm cabs, one 4 ohm and two 8 ohm cabs, or two 4 ohm cabs. additionally, one 4 ohm cab and one 8 ohm cab will give you a load (impedance) of 2.67 ohms.
     
  9. will33

    will33

    May 22, 2006
    austin,tx
    Judging from my own experience, I wouldn't fall for the "low ohms, get more power from your amp" spiel. Doubling your power equates to about +3db. That's one of the smallest, yet still noticable changes in volume recognized by the human ear and that's only if your cab can actually reproduce those changes, most of them cannot.

    It just seems to me a way of saying you're way powerful when you're not. I judge my amps on what they can do to an 8ohm load, be they bassamps, poweramps or whatever. Touting higher power at lower ohms to me equates to telling someone you have a 16channel board when you can only plug 4 mics into it.

    Power at 8ohms = power. How many mics you can plug in = how many channels you have.
     
  10. Simple to some, very helpful to me. Thank you for posting these figures.
     
  11. ejaggers

    ejaggers Supporting Member

    Aug 18, 2009
    Fort Worth, tx
    To: IvanMike and will33

    Thanks for the info. I really appreciate you helping me with this because I like walking into a repair shop having some idea of what’s going on. I’m surprised about how few responds I got from this post, because I can tell there are a lot of sharp people on this site.

    Just like OneMan said, “Simple to some, very helpful to me”, and I totally agree.
     
  12. No disrespect, but what's to be surprised about? A lot of people on this site are sincerely helpful people, but almost anybody will inevitably get tired of answering the same questions over and over and over. That's the whole reason behind the creation of the sticky in the first place.

    Someone who points you to the sticky is doing you a favor, honestly. A fair amount of work went into making it, and it wasn't put there just to blow people off, it was put there to help in an efficient way. Your questions have all been asked many times here, and I guarantee the answers are in the sticky if you look. Or if you search some of the other threads.
     
  13. UncleBalsamic

    UncleBalsamic

    Jul 8, 2007
    UK
    Also, generally it's good practice to listen to what Bill says. He's a really clever bloke.
     
  14. IvanMike

    IvanMike Player Characters fear me... Supporting Member

    Nov 10, 2002
    Middletown CT, USA
    right on.............that's kinda why i wrote the ohms faq and why others have written some great faqs or linked some really good threads.
     
  15. ejaggers

    ejaggers Supporting Member

    Aug 18, 2009
    Fort Worth, tx
    Richard Lindsey

    No disrespect taken. As I said earlier, I’m not that sensitive. As I also said earlier, I didn’t find the answer in the faqs.

    Basically my question (more clearly) is since BW baskets are $110 each would you recommend biting the bullet on an amp that I may replace later or is there a different (brand) speaker that will suffice.

    I’m having a hard time seeing why people think I was being disrespectful or insulting to Bill. I’ll repeat again that all I said was seems to me it was just as easy to say something like, “Yeah, Carvins are cheaper and sound just as good”.

    And yes I was truly surprised, but I don’t know what you’re reading into that.
     
  16. johnk_10

    johnk_10 vintage bass nut Supporting Member Commercial User

    Feb 16, 2008
    Thousand Oaks, CA
    John K Custom Basses
    if by BW you mean Black Widows, those are pretty nice speakers when they are working properly.

    if you go with new speakers, i'd recommend Eminece 3015's. they'll handle just about anyything you can throw at them. (2 8 ohm speakers wired in parallel = 4 ohms), which will work great with your head. you do not need to run a 2 ohm cab with it, and with high efficiency speakers, could probably barely tell the difference whether the cab is 2 or 4 ohms.

    2 cents............
     
  17. Grooveman1961

    Grooveman1961

    May 8, 2006
    Here are my answers to your questions:

    1. You would use 8ohms when your amp was designed to use an 8 ohm load. Some amps cannot go below an 8 ohm rating. As an example,I have a gk800rb, that has two power amps built in. One hig power one low power. The low power amp will not do anything less than an 8 ohm load. Your head says 200 watts at 2 ohms. You can take this to mean that you can safely connect a 2 ohm load. Your cab says 4 ohms, its higher than 2 ohms, so your ok. You would also use 8 ohm speakers together to get lower OHM loads. 1=8, 2=4, 4=2. Speakers are offered in several ratings, like 4, 8,16, and 32 ohm configurations in order to give flexibility in congfiguring combinations of speakers with different amps.

    2. Two eight ohm speakers in one cabinet connected in paralell gives a 4 ohm load. you cannot get a 2 ohm load from 2, 8 ohm speakers. Two four ohm speakers in paralell gives you the 2 ohms your after. Your cab has 2 8 ohm speakers in paralell, to give the 4 ohm rating on the cab. If you had another one of those cabs, both of them together would be 2 ohms. This may be why Peavey set those up that way, so you could have 2 cabs if you wanted.

    3. The peavey baskets are great quality, and should work well in your peavey cabinet. Other 15's could work as well, but you will end up spending the same or more to get similar results. If you sell your rig, having it equipped with OEM speakers will generally be worth a little more.

    Hope this helps.
     

Share This Page

  1. This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
    By continuing to use this site, you are consenting to our use of cookies.