Whats The Difference Between 2,4 or 8 ohms?

[Munjibunga]

You also could PM me, and hope I'm in a good mood.

 

[splattergod]

so if i was to add another 810e cabinet to my SVT CL i would switch the amp to 2ohms?

 

[epic!]

After reading through this and the Ohmns FAQ i have a question. This may be a bit of dumb question but none-the-less one that I am having a bit of trouble understanding. Why would you want a high impedance rated cab (assuming only 1 cab)? Seems like everyone is always striving for a louder amp, so why not stick with 4 or even 2 ohmns if your head can handle it? Do higher impedance cabs sound better? Do the speakers on high impedance cabs not distort at high volumes? Thanks for the help

 

[CaptJoshGrizzly]

No. Your head must have equal or lower impedance

Head Cab
4ohm 8ohm = GOOD
4ohm 4ohm = GOOD
4ohm 2x8ohm = GOOD
4ohm 3x8ohm = BAD
4ohm 2x4ohm =BAD
4ohm 40hm + 8ohm = BAD
2ohm up to 4x8ohm or 2x4ohm = GOOD

gold. I actually read the sticky so i got it, but this is basically what people are concerned about.

 

[Jaco who?]

Why would you want a high impedance rated cab (assuming only 1 cab)? Seems like everyone is always striving for a louder amp, so why not stick with 4 or even 2 ohmns if your head can handle it? Do higher impedance cabs sound better? Do the speakers on high impedance cabs not distort at high volumes? Thanks for the help

OK, I have to be quick so TB's stupid software doesn't kick me off of here, but there's always a compromise between available power and the speaker surface area you have to work with.

My old Peavey that does 450 watts @ 2Ωs works best with two 4Ω 2x12 cabs, but if I was using say, a GK 700 rbII with 480 watts @ 4Ωs, I'd be better off with either one 4Ω 4x10, or two 8Ω 2x10s or 2x12s.

8Ω 4x10s are sort of stupid unless you've got stupid power to work with, like a GBE1200 or something similar, by the same token, 4Ω 2x10, 1x12 cabs are stupid unless you've only got maybe 150 watts total to work with. All gross over-generalizations, that causes mucho grief for many around here, so I'll stop now.

 

[billfitzmaurice]

After reading through this and the Ohmns FAQ i have a question. This may be a bit of dumb question but none-the-less one that I am having a bit of trouble understanding. Why would you want a high impedance rated cab (assuming only 1 cab)? Seems like everyone is always striving for a louder amp, so why not stick with 4 or even 2 ohmns if your head can handle it? Do higher impedance cabs sound better? Do the speakers on high impedance cabs not distort at high volumes? Thanks for the help

Because you never know when you may need to add a second cab, and because most cabs reach their maximum output at no more than half their rated power, so 'getting all the watts out of my amp' usually won't get you any louder anyway.

there's always a compromise between available power and the speaker surface area you have to work with.

Driver surface area is moot. Driver displacement (cone area x excursion) is what determines output capacity.

 

[lbwdog]

My long standing theory is; If you need to operate your amp at it's lowest impedance, then you really need a more powerful amp.

I've fortunately played G-K 800RB and 700 RB for years, and they have had enough power (into 8 Ohms) to do any gig, and that includes "Big Stage" events such as arenas and outdoor festivals.
On some of these larger gigs, I will add another 8 Ohm cab (just because), which I couldn't do if I had a 4 Ohm cab.

I don't feel like my 8 Ohm 410 Goliath III is stupid at all in this case, but I certainly wouldn't have use for a 4 Ohm 112 or 210, as these would definite need a second cab to produce the clean volume I normally need.

 

[Jaco who?]

Driver surface area is moot. Driver displacement (cone area x excursion) is what determines output capacity.

Hence the general disclaimer: "All gross over generalizations", but technically you are correct, oh great one, I should have used "driver displacement" in that sentence.

 

[Marley's Ghost]

Another zombie thread, and ohms of all things.

 

[steveksux]

One point in this theads reference link I think is incorrect
In it states "Doubling your watts results in a 3 dB increase in volume, which is generally the smallest change in volume a person can hear. That’s why using a 4 ohm cabinet instead of an 8 ohm cabinet with your head doesn’t always blow you away."

I believe, in fact that 1 decibel, not 3 is the minimum change that one can discern. 3 decibels is indeed a doubling if volume, however a doubling is not what the average person might conclude from that amount of change. Perception factors in here.

You're missing the context. The questions usually asked are something like "Would getting a new amp 50/100 watts more than my 200 watt head make me a lot louder" and the response is "even doubling the wattage only gets you 3dB louder, which is about the smallest increase which you would notice".

Meaning you would notice it, it would stand out, but not be overwhelming. They're not saying its the smallest dB increase people can detect if they're straining to hear if there's a volume difference.

Randy