#1
Say i have a little combo amp that uses a 4ohms speaker, can i use a different speaker like a 8ohms one?
#2
maybe not cos ohms is resistance so a 8 ohm would have twice the resistance.
probly wont work but i dunno rele. doubt it would break it to try
#6
Quote by call1800ksmyazz
What??? Your wrong. Ohms/impedence has nothing to do with this.

It wont work.


Please explain to me why this won't work.
MG Free At Last
#9
P=V^2/R For example, you have a 100 watt amp at 4 ohms. That means the amp is putting out a voltage of 20 V. Double the resistance, and you have 50 watts.
MG Free At Last
#11
Quote by call1800ksmyazz
^-In reference to your MG100?

Haha, I prove you wrong so you start talking crap about my gear. Good one. Shouldn't you be in the pit or something?
MG Free At Last
#12
Kerry knows more about building/modifying amps and electronics in general than you will dream of, N00blet. Run and play with your "UBER MODDED OMG BETTER THAN AN AMERICAN SQUIER STRAT". Maybe you will even put a flamethrower on it. Or build a guitar out of paper mache.

Its simple, you plug a 8 ohm speaker into a 4 ohm head/power amp/whatever, its going to eventually smoke the amp because of it not being loaded correctly. It may work, for a period of time, but the tone is going to sound screwed all to hell. Have fun.

And dont forget to take pictures of the smoke. We love retarded mistakes here.

Silly 06'ers.
Quote by givemeaname
My sisters pretty hot aswell
#13
there's one problem with your "proving wrong" it doesn't work. try putting a 4 ohm resistor there instead of the speaker, just watch, maybe wear goggles...

its not resistance, its impedance. if it was the same thing speaker attenuators would be a $2 pot. I'd advise always using the correct impedence speaker for your amp, it may take 8ohms and itmay be quieter, but its not for the reasons yousaid. it also wont be 50w, as the original 100w is RMS, this isn't straightforward physics where your argument might stand up, its more complicated.


"You're a MESS!"
#14
Owned by The1963Riffer and liquidstate haha.

But really, like they said, if it does work, it wont be for long. Its like saying im gonna plug my 100w head into my small little computer speaker. You plug into the wrong impedence (1 thing wrong) and then you are using 100w over the speakers maybe 5w rating (2 things wrong).

Sometime its going to get all messed up and your going to come and ask us for how to fix it. Well we will tell you that we had told you not to do it in the past.

Its not a good idea, wait to get a new speaker/cab, its a combo so its not like you cant use it just use its internal speaker.

If you REALLY want to use it with the 8ohm cabinet, open up the amp, find the output transformer, find the 8ohm jack, and attach a 1/4" jack CORRECTLY to it and then you can use the 8ohm speaker. If it has this tap only...

Kerry
#15
Quote by liquidstate
there's one problem with your "proving wrong" it doesn't work. try putting a 4 ohm resistor there instead of the speaker, just watch, maybe wear goggles...

its not resistance, its impedance. if it was the same thing speaker attenuators would be a $2 pot. I'd advise always using the correct impedence speaker for your amp, it may take 8ohms and itmay be quieter, but its not for the reasons yousaid. it also wont be 50w, as the original 100w is RMS, this isn't straightforward physics where your argument might stand up, its more complicated.


I'm not sure what kind of 4 ohm resistor you're talking about, but if you get a high powered enough one, I don't think anything would happen. You,re right about it not being exactly 50 watts, just like it's not ACTUALLY putting out 100w, the point is, it's not going to be as loud, which is what I said in the first place. And if not for the reasons I saiid, for what reasons?

Quote by moron #1
But really, like they said, if it does work, it wont be for long. Its like saying im gonna plug my 100w head into my small little computer speaker. You plug into the wrong impedence (1 thing wrong) and then you are using 100w over the speakers maybe 5w rating (2 things wrong).

Power ratings have nothing to do with what we're talking about.

Quote by moron #2
Kerry knows more about building/modifying amps and electronics in general than you will dream of, N00blet. Run and play with your "UBER MODDED OMG BETTER THAN AN AMERICAN SQUIER STRAT". Maybe you will even put a flamethrower on it. Or build a guitar out of paper mache.

Its simple, you plug a 8 ohm speaker into a 4 ohm head/power amp/whatever, its going to eventually smoke the amp because of it not being loaded correctly. It may work, for a period of time, but the tone is going to sound screwed all to hell. Have fun.

And dont forget to take pictures of the smoke. We love retarded mistakes here.

Silly 06'ers.

I don't think you have any idea what you're talking about.
MG Free At Last
#16
Quote by call1800ksmyazz
What??? Your wrong. Ohms/impedence has nothing to do with this.

It wont work.

He is correct. It won't be as loud.
Quote by ljplum12
P=V^2/R For example, you have a 100 watt amp at 4 ohms. That means the amp is putting out a voltage of 20 V. Double the resistance, and you have 50 watts.


Quote by call1800ksmyazz
^-In reference to your MG100?

1800, you got oh so dreadfully pwnt. And the MG100 has nothing to do with it. His statement is true.

Quote by The1963Riffer
Kerry knows more about building/modifying amps and electronics in general than you will dream of, N00blet. Run and play with your "UBER MODDED OMG BETTER THAN AN AMERICAN SQUIER STRAT". Maybe you will even put a flamethrower on it. Or build a guitar out of paper mache.

Its simple, you plug a 8 ohm speaker into a 4 ohm head/power amp/whatever, its going to eventually smoke the amp because of it not being loaded correctly. It may work, for a period of time, but the tone is going to sound screwed all to hell. Have fun.

And dont forget to take pictures of the smoke. We love retarded mistakes here.

Silly 06'ers.

No, untrue. I've heard cases of 4 ohm amps that have had been run with a 16 ohm speaker for 20 years or so. And I know that I *can* run my Bassman's 4 ohm tap at 8, or 16 ohm. 8 ohms sound worse, and 16 ohms sounds pretty bad comparatively, but it works fine. 16 ohms I don't think I would pull off for long, but I'd feel comfortable running it on 8 ohms for ages. Why? It's sturdy output transformer. And FWIW my homebuilt amp can run at 4 ohms and 16 ohms with it's 8 ohm tap, and my Peavey Classic 30 can be run at 8 with it's 16 ohm tap.

Most times, mismatching won't damage anything. There are amps with finicky output transformers that will blow, old Marshalls are famous for this. But still, this issue is rather overhyped, IMO. Mismatching does not equal an imminent explosion.

Quote by call1800ksmyazz
Owned by The1963Riffer and liquidstate haha.

But really, like they said, if it does work, it wont be for long. Its like saying im gonna plug my 100w head into my small little computer speaker. You plug into the wrong impedence (1 thing wrong) and then you are using 100w over the speakers maybe 5w rating (2 things wrong).

Sometime its going to get all messed up and your going to come and ask us for how to fix it. Well we will tell you that we had told you not to do it in the past.

Its not a good idea, wait to get a new speaker/cab, its a combo so its not like you cant use it just use its internal speaker.

If you REALLY want to use it with the 8ohm cabinet, open up the amp, find the output transformer, find the 8ohm jack, and attach a 1/4" jack CORRECTLY to it and then you can use the 8ohm speaker. If it has this tap only...

Kerry

If you have a 100 watt head and you plug it into a computer speaker, ohmage isn't the first consideration. The first issue is the wattage, not the ohmage. The speaker would fry the coil, then you'd have an open connection between the two output leads of the transformer, which could fry it. When it comes to ohmage, most computer speakers would work fine.

Somehow we've neglected to ask if the amp is even tube? If not, it's safe anyways. SS amps have no problem jumping around ohms for the most part, this is why on commercial amps you see stuff like "200 watts at 4Ω, 100 at 8Ω." You can run SS amps unloaded (some tubes too actually, but let's not go there).

Quote by liquidstate
there's one problem with your "proving wrong" it doesn't work. try putting a 4 ohm resistor there instead of the speaker, just watch, maybe wear goggles...

This will work just fine, if the wattage rating is high enough.

Quote by liquidstate

its not resistance, its impedance. if it was the same thing speaker attenuators would be a $2 pot. I'd advise always using the correct impedence speaker for your amp, it may take 8ohms and itmay be quieter, but its not for the reasons yousaid. it also wont be 50w, as the original 100w is RMS, this isn't straightforward physics where your argument might stand up, its more complicated.


Hmm? There are plenty of amps with fixed resistors replacing the speaker, if that's what you're getting at with the pot. The pot would also change the impedance when you rotate it, that would be a larger problem.

This post is pretty unintelligible actually, I'm not sure what your point is or what you're saying. Nevertheless, if you're backing up Kerry here, you're wrong.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#17
Quote by That_Pink_Queen


Somehow we've neglected to ask if the amp is even tube? If not, it's safe anyways. SS amps have no problem jumping around ohms for the most part, this is why on commercial amps you see stuff like "200 watts at 4Ω, 100 at 8Ω." You can run SS amps unloaded (some tubes too actually, but let's not go there).


yes, what I said ages ago
#18
^As you did my good man!

ljplum12: You rule dude.

In short:
If it's solid state, go ahead and do the change, but it will be quieter.
If it's a tube, it's a better idea not to as we don't know what your output transformer can handle. It will probably be ok, but it's always best to match up.
I'm not very active here on UG currently.
I'm a retired Supermod off to the greener pastures of the real world.
#19
Thanks, I'm just glad there was someone else on here with some knowledge that could back me up.
MG Free At Last
#20
to what pink said: i can run my tube amp for short periods of time without my cab, but i wouldn't try it for long. it's usually that, oops, forgot to hook up my cab, reattach it thing.
Quote by corduroyEW
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