Converting A Cabinets Ohmage?

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sirpunkly

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I have a Marshall cab with 4 speakers (16 ohms each) which wired in series makes the cab a 16 ohm cab. My amp's output at 16 ohms is 18w when I could have more at 8 ohms and 50w at 4 ohms. Is there anyway to re-wire so that I can have my cab at 8 ohms, or better yet 4? Some sort of convertor or something? Thanks!
 
If they are 16 ohms each then wiring them in series makes for more than 16 ohms.... it makes for 64. If wired in series parrallel they would be 16 ohms. Wired all in parrallel should make 4 ohms. I am assuming that these are actually 16 ohm speakers tho. If you are getting 16 ohms by wiring 4 speakers in series than they are actually 4 ohm speakers.



Simon
 
If they are indeed ALL 16 ohms EACH, and in total it's 16, the only way that's possible is if they are wired this way:
1 and 2 in series, 3 and 4 in seried, and 1/2 wired in parallel with 3/4. 1+2 = 32, 3+4 = 32: 32 in parallel with 32 is 16.

So is there a switch on your amp that allows IT to go from 16 top 8 to 4 ohms? If so, I understand your problem. If not, then if they're both 16ohms, that's perfect. Matching is more important than anything else when it comes to impedance.
 
If the output on your amp is 16 ohms then you should run a matched speaker cab (16 ohm also.) Different resistance (ohms) can cause your amp to overheat. Chances are that you can run an 8 ohm cab without doing any damage but a 4 ohm cab is likely to put too much strain on the amp. An 8 ohm cab might give you a little more volume but it will also distort more (actually more of a slur, not the good kind of distortion) so if you want a clean sound stick to the 16 ohm cab.
 
Wouldn't putting all four 16 ohm speakers in parallel make the cab's imp. 4 ohms, thereby solvong your problem? You said they were in parallel, and are outputting 16 ohms together, which confuses me....
 
http://www.colomar.com/Shavano/impedance_proc.php

^^^ Impedance calculator ^^^

The links below diagram each speaker configuration along with the calculations for the final impedance.

Four 16 ohm speakers in series:
http://www.colomar.com/cgi-bin/h_impedance_proc?16Z16Z16Z16ZxZxZxZxZxZxZxZxZxZxZxZx
Impedance = 64.0 Ohms

Four 16 ohm speakers in series/parallel:
http://www.colomar.com/cgi-bin/h_impedance_proc?16Z16ZxZxZ16Z16ZxZxZxZxZxZxZxZxZxZx
Impedance = 16.0 Ohms

Four 16 ohm speakers in parallel:
http://www.colomar.com/cgi-bin/h_impedance_proc?16ZxZxZxZ16ZxZxZxZ16ZxZxZxZ16ZxZxZx
Impedance = 4.0 Ohms
 
Yea, I'm a little unclear as to what you currently have as well...

What is the output impedance (ohms) of your amp? Is it switchable to 4 ohms?

How are your speakers currently wired and what is the impedance (ohms) of your complete cabinet as it is today? If you know what the ohm's of each speaker is that would be great too. Are they all the same model speaker?
 
No offense, but you don't seem to know enough about impedance, parallel and series to attempt to do what you want. If you mis wire the cab for either a dead short (Not too hard to do if you aren't careful) or open/no connection you could damage your amp. I would take it into a shop and have them do it for you, they shouldn't charge you that much since it's pretty simple IF you know know what you're doing.
 
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