4 ohm cabinets help

Discussion in 'Amps and Cabs' started by cosmos, Aug 14, 2005.


  1. cosmos

    cosmos Member

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    Hi y'all,

    I'm looking for a 1x12 or 2x12 cabinet, that works at 4 ohms. It seems to me that pretty much every brand that has 2x12s are 8 ohms. Do you guys have any suggestions?

    Also, would it be possible to wire a 2x12 in a way that it would accept 4 ohms? For example, this Koch 2x12 cabinet has 2 8 ohm speakers, and has these inputs:

    [​IMG]

    Would it be possible to re-wire this? So that I would have a 4 and an 8 ohm input for example? (of course, I realise that I wouldn't be able to use it stereo then)


    thanks!
     
  2. sled

    sled Member

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    no... and maybe...

    with two speakers the cab is either two 4ohm in series or two 16 ohm in parallel (probably two 16 ohm)

    if it's two 4 ohm in series, you can use just one speaker for 4 ohms, but I wouldn't...
     
  3. waxnsteel

    waxnsteel Member

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    I have a late eighties/early 90's Fender 2X12" cab that's 4 Ohms, and don't use it. I used to use it with an old bandmaster head. If you're interested, I'll figure out what's in it, and maybe we can make a deal...
     
  4. Fireball XL5

    Fireball XL5 Supporting Member

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    As far as 2x12 cabs go... a lot of the Dr. Z Z-Best cabs are wired to 4 ohms. The Z-Best is a great 2x12 cab!
     
  5. daneswede1

    daneswede1 Member

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    I like the fact your asking that question . I actually have just switched to playing at 8 ohms with my Marshall 2203x head through my Bogner Ubercab which is wired at 8 ohms. X pattern 2xv30s n 2xG75s. Personally, The sound has a nice sompressed fgeel and a fast attack. Playing through my Marshall 1960a cabinet at 16 ohms just wasnt cutting it to me as far as what I wanted my ear to hear.

    Dont get me wrong, Running at 16 ohms is great and i have been doing that with JCM 80os for the past 17 years!! Its just I found that the 8 ohms sounds better to me as well as this new speaker configuration in the Bogner Ubercab! I also have a BOgner Uberschall. I run both amps together in a dual-mono - aural sound with a TC G Force in stereo through both. SOunds like godzilla stomping through your town! Nice tones.

    I have not tried 4 ohms. I do know the less the ohmage, the less your pushing the trannie so ive been told anyway. Good luck with your search!
     
  6. cosmos

    cosmos Member

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    Well, I live in Amsterdam, and I'm assuming you're US, so I'm afraid that 'll be a hard thing.

    @daneswede1: I use a Bassman Export head, so I don't have the option of having 8 ohms. It's 4 ohms only..
     
  7. John Phillips

    John Phillips Member

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    Not a personal dig at you, but be careful with posting stuff like this. There is no "running at 16 ohms" sound or "running at 4 ohms" sound, inherently, and neither "pushes" the transformer more or less.

    What there is, is matching or not matching and these do change the load and stress on the transformer and power tubes. You should NOT mismatch impedances more than a factor of two in either direction, and even then it's always safer for the amp if they do match.

    The reason your Bogner cab sounds so different to your Marshall is very little to do with the change in impedance and almost everything to do with the different speakers and cabinet construction.

    There is also a difference between running the same speakers in a 4-ohm or 16-ohm configuration from the same amp, correctly matched in both cases, but it's relatively subtle.

    Sorry for the lecture, but when people start to say things about "amps sounding better at 8 ohms" or whatever, it can be very misleading and even cause people to assume that the impedance setting is the only thing that needs to be changed... which is a good way to cook your power tubes or even (worst case) your output transformer. Amps almost always sound best matched, whatever the cab impedance is - especially if the kind of sound you want is big and powerful - and are most reliable like that.
     
  8. daneswede1

    daneswede1 Member

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    I understand what you are saying and maybe they way I describe the whole Ohms thing was misleading. This is what I meant. You did say that if you run lets say for example a Marshall 2203x hgead set to 16 ohms run through a Marshall 1960a 4x12" cabinet also set to 16 ohms this is "matched" as you say and correct! What I did was change the Marshall to 8 OHMS setting and then I changed the switch on the back of my Marshall cabinet to 8 OHMS (It has a switch on the back of my cabinet to run at either 16 or 8 ohms) I do know as well that when you switch it to 8 ohms you are now only running two speakers fronm this cabinet. Now what this means is that I am now running my Marshall head at 8 ohms and my Marshall cabinet at 8 ohms with two of the four speakers running (Still correct and matching) Yes it is SUBTLE but i can hear a differance. I dont know how to explain this but to me any way it sounds more compressed. The second thing I did was run my Marshall head STILL SET AT 8 ohms and ran it into my BOgner Ubercab which is already wired at 8 ohms (Again it is matching in the OHMAGE DEPT!) This time it even sounded better again. I know that the speaker configuration has a lot to do with this and the cabinet being a straight formation as well as you say. However, and again IMO I feel that running my Marshall at * ohms through the 8 Ohms Ubercab by Bogner changed the compressed feeling and attack of my sound. I never did incorrectly un match my sound at any time. The only thing I am guilty of is claiming that the MATCHED 8 ohms head and 8 ohms cabinet gives you a "subtle" just as you say yet noticeable to me anyway differance in the attack I will say then if compressed is not the correct term. I have actually reead a lot of articles about running at differant OHMS of course it must always be matched and I agree again with you that you shoyuld never run a 16 ohm cabinet with an 8 ohm head. No good. Thanks for your post and I needed to clarify what I was saying.
     
  9. John Phillips

    John Phillips Member

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    Actually you usually can run a 16-ohm cab with an 8-ohm head (or the other way round) but not 4 and 16 (in either direction) - that's too big a mismatch.

    Yes, the impedance does make a small difference (assuming everything else is the same and matched) but the other factors, including the number of speakers, series vs. parallel wiring, type of cab, type of speakers etc are all more important. The biggest difference with the Bogner cab vs. the Marshall one is the two V30 speakers, which are a lot more solid-sounding (and sensitive) than the G12T-75s, so they really fill out the tone.

    I had to point it out though! When I started repairing amps about twenty years ago, I saw quite a few old Marshalls with blown OTs caused by the 'trick' of "getting a better tone" (which in those days really just meant more distortion) at lower volume by running the amp at 4 ohms into a normal 16-ohm cab. It works - until the power tubes blow or the OT dies. Luckily this 'trick' seems to have been forgotten now we have better MV amps, pedals, attenuators and stuff...

    :)
     
  10. Kiwi

    Kiwi Silver Supporting Member

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    Yes, the stock Matchless ESD 2x12 cab is wired to run at 4 ohms.

    Stellar swirly 3-D sound from two mismatched speakers.

    Kiwi
     
  11. daneswede1

    daneswede1 Member

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    I FINALLY UNDERSTAND. THank you SOO MUCH! Im glad you pointed out the fact that the V30s give you a more solid sound and sensitive type tone. THAT IS EXACTLY WHAT IS going on here! I just cant believe the difference. I was going to sell the Marshall 1960a cabinet I got and get another Ubercab.WOuld you recommend that or just change all the spealkers in the Marshall?

    Thx again!!!
     
  12. John Phillips

    John Phillips Member

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    Cheapest and easiest is just to put two 16-ohm V30s in the Marshall. What I'd actually do is to change the wiring so instead of stereo left/right, the pairs are the V30s and the G12T-75s - that way you could run either, or both - that will give you more tone options for no extra cost :). You could still have them physically in the X-pattern, just connected differently.

    There is a small tonal difference between 8 and 16 ohm versions of the speakers. Also, if you run both cabs together there will be a slight mismatch since they won't be the same impedance - it will work fine, but the Bogner cab will take more power than the Marshall.

    Next most expensive would be to replace all four speakers in the Marshall with 8-ohm ones, which would get you closer to the same sound and allow equal power distribution.

    If you want exactly the same sound, you really need another Bogner cab - even with the same speakers, the Marshall won't sound quite the same since it's built differently and wired differently. That's the most expensive option though.
     
  13. cosmos

    cosmos Member

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    @John Philips:

    Those 2 V30s, are they in the bottom, or in the top of the cabinet?
     

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