4 ohm vs. 8 ohm cab sonic differences? Don't worry, I read the FAQ...

[tbassist4]

So, is there actually a sonic reason to buy an amp/cab setup with one or the other, or does it just have to do with calculating the right load for a given amp? I know 8 ohm cabs put up more resistance, but why would you choose that over a 4 ohm cab? Does this have to do with tone, or rather with how you want to configure an amp/cab setup? Are they designed for different size setups, and what do most people use?

For instance, using Generic Head X rated at 4 ohms, you could attach either two 8 ohm cabs in parallel, or four 4 ohm cabs in parallel, correct? Unfortunately, I'm new to "big boy" amps/cabs, so I have no idea which would be more advantageous and why.

[Mr. Foxen]

The maths bit is wrong. The advantage of 8 ohm cabs is that most amps go down to 4 ohm, so you have the option of a second cab. The advantage of a 4 ohm cab is you can squeeze a tiny bit more power out of the amp over a single 8ohm cab, if your amp is really weak, but if you want the power for volume rather than bragging, better off with the two 8 ohm ones.

[username1]

four 4ohm cabs in parallel would give a load of only 1 ohm

[tbassist4]

Originally Posted by Mr. Foxen

The maths bit is wrong. The advantage of 8 ohm cabs is that most amps go down to 4 ohm, so you have the option of a second cab. The advantage of a 4 ohm cab is you can squeeze a tiny bit more power out of the amp over a single 8ohm cab, if your amp is really weak, but if you want the power for volume rather than bragging, better off with the two 8 ohm ones.

So this has absolutely nothing to do with tone, just volume? 4 ohm and 8 ohm cabs are just designed for different configurations that that's all?

[tbassist4]

Originally Posted by username1

four 4ohm cabs in parallel would give a load of only 1 ohm

So it would, my bad on that. A 1 ohm load would fry how fast?

[Son of Bovril]

It has been suggested before that some amps sound better running at 8 ohms (example: eden) and I personally have a Fender MB 1200 poweramp which sounds better to me running at 2 ohms but whether or not there is an actual tonal difference or hust a volume difference is still speculative...

more often and importantly you choose your cabs resistance based on how many you plan on running and what your head can handle

[waleross]

+1 on what has already been stated. Its about the correct connections first. I have the Fender TB1200 head which will accept loads down to 2 Ohms. I try not to mix up my cabs but I know I could run (2) 8ohm cabs (a 410HE and 115 ) and not have any connection problems.

[mulchor]

When kids say "I read the FAQ/textbook" . . . what does that mean they actually did?

[Ric5]

I build my own cabs. They are either 2x10, 1x15, or 1x18. They are all 8 ohm. Then I can always use 2 cabs with a head.

[Alex1984]

Originally Posted by tbassist4

So it would, my bad on that. A 1 ohm load would fry how fast?

Faster than an egg I suppose. J/K, most modern amps have some sort of protection against shorts (ie. ultra-low impedances).

+1 to the above mentioned reasons of adding additional cabs. Another reason why SOMETIMES (probably quite rare) that might be preferrable is power distribution. Supposed you have a head stable down to 2 ohms. If you have a 410 at 4 ohms, and you want to add another 210, if you used a 4 ohm cab, power distribution will be 50/50 between the 2 cabs, so each driver in the 210 sees more power than the ones in the 410. If you use an 8 ohm 210, the power would be even, although I personally wouldn't do that.

[Mr. Foxen]

Originally Posted by tbassist4

So this has absolutely nothing to do with tone, just volume? 4 ohm and 8 ohm cabs are just designed for different configurations that that's all?

More power can mean a bottomier tone can be achieved, to an extent, but it shouldn't affect much at same settings. If you have a valve amp with an output transformer set to the wrong impedance, it can affect the tone, so that sort of counts?

[tbassist4]

Originally Posted by mulchor

When kids say "I read the FAQ/textbook" . . . what does that mean they actually did?

Well it probably means they did something more useful than troll a thread and be condescending to the OP.

Originally Posted by Alex1984

Faster than an egg I suppose. J/K, most modern amps have some sort of protection against shorts (ie. ultra-low impedances).

+1 to the above mentioned reasons of adding additional cabs. Another reason why SOMETIMES (probably quite rare) that might be preferrable is power distribution. Supposed you have a head stable down to 2 ohms. If you have a 410 at 4 ohms, and you want to add another 210, if you used a 4 ohm cab, power distribution will be 50/50 between the 2 cabs, so each driver in the 210 sees more power than the ones in the 410. If you use an 8 ohm 210, the power would be even, although I personally wouldn't do that.

Ah, I see, so unless you had like a 1x15 or some other robust speaker then it might not be a good idea to give a higher proportion of power to the other?

Originally Posted by Mr. Foxen

More power can mean a bottomier tone can be achieved, to an extent, but it shouldn't affect much at same settings. If you have a valve amp with an output transformer set to the wrong impedance, it can affect the tone, so that sort of counts?

I see, so the effect is somewhat marginal except for the apparent connotations of adding more power; that makes sense. Haha, and yeah, I never considered the negative side mismatched impedance.



Thanks so much for all of the help!
Tyler

[Pilgrim]

I don't believe there is a difference in sound - just flexibility in matching cabs to the head.

[VanillaThundah]

yeah, its basically to match up with what your amp can handle. My Carvin BX500 does 500w RMS at 4 ohms, so my 2x10s is a 4-ohm cab to squeeze out as much wattage as I can. Tonally, I haven't heard any difference out of the cabs....heads can be a totally different story, from what I hear

[mongo2]

My 15" 4 and 8 ohm drivers sound very different in the same cab.

But then again, my 4 ohm is a Peavey Black Widow, and my 8 ohm is an EV Pro 15L

[mulchor]

Originally Posted by tbassist4

Well it probably means they did something more useful than troll a thread and be condescending to the OP.

I think it's always been this way, but a good bit of why I don't teach (very many) undergrads anymore.

The first post proves you didn't read the FAQ like you claim.

Four 4 ohms in parallel.
8 is more impedance than 4 . . .

But I appreciate that upon making claims like this, people must have done something they think is equiv to doing the homework.

I'm not trolling, I'm biting on a frequently trolled topic...

I hope you find the answers you're looking for and can get back to

[Alex1984]

Originally Posted by tbassist4

Ah, I see, so unless you had like a 1x15 or some other robust speaker then it might not be a good idea to give a higher proportion of power to the other?

Well, that is one reason why people MIGHT do it, but I personally wouldn't, cuz it'd be too much to think about when other cabs are just as accessible. To sum up though, I'd say sonic differences are much, much less than electrical differences.

[babebambi]

lol, they may well have read it, doesn't mean that they remember it; even less so that they understand it ...

Originally Posted by mulchor

I think it's always been this way, but a good bit of why I don't teach (very many) undergrads anymore.

The first post proves you didn't read the FAQ like you claim.

Four 4 ohms in parallel.
8 is more impedance than 4 . . .

But I appreciate that upon making claims like this, people must have done something they think is equiv to doing the homework.

I'm not trolling, I'm biting on a frequently trolled topic...

I hope you find the answers you're looking for and can get back to

[JimmyM]

if everyone did searches, there would be no need for talkbass.

the only real difference is you get more headroom with a smaller impedance on amps without output transformers like tube amps and the warwick hellborg power amp. but i say big deal. it's so little headroom and that addition of a second cab makes so much more difference that i believe the differences to be moot.

[SactoBass]

I recall reading somewhere on the Internet (dangerous, I know) that when an amp is being run at 4-ohms instead of 8-ohms, the amp's damping factor is halved. Would that suggest that if your desire is to have tighter bass in the low notes, that running the amp at 8-ohms would be better as it would have twice the damping factor?