8 Ohms or 4 Ohms?

[diosito]

Hey bass players.
I just bought a Gallien-Krueger 1001RB-II (460W @ 8 Ohms / 700W @ 4 Ohms) head.
and I had a Behringer Ultrabass BB210 speaker with a 8 Ohms impedance.
What does this mean, that I am only getting 460w?
Also, how do I switch my Gallien-Krueger from 8 Ohms to 4 Ohms? Is it automatic?
And finally, which impedance is better, 8 Ohms or 4 Ohms?

[WingKL]

Have you read the FAQ?

[packhowitzer]

^this

[SteveHeissner]

One 8 ohm speaker = 8 ohms. Two 8 ohm speakers = 4 ohms. Two 4 ohm speakers = 2 ohms, which is lower than the GK head goes and may damage the amp. The way you "switch" your GK head from 8 ohms to 4 is by adding a second 8 ohm speaker. Happy playing. That GK head is nice IMO.

[Warrior_Bass]

Do yourself a favor and read the FAQ!

[Rick Blanc]

What does this mean, that I am only getting 460w?

Simple answer, yes

how do I switch my Gallien-Krueger from 8 Ohms to 4 Ohms?

By adding another 8 Ohm cab.

which impedance is better, 8 Ohms or 4 Ohms?

Neither. The spec you see on your amp is only telling how much wattage you get at what Ohm. You could get a 4 Ohm cab and get all your watts and you'd think you'd be louder but not necessarily.
700 watts with one 410 cab would not be as loud as two 410 8 ohm cabs. It can get really confusing if you just starting to try to understand this stuff so you should definitely read the FAQs.

[Vic Winters]

Be careful with the volume, that amp will destroy those speakers.

[modulusman]

Originally Posted by Vic Winters

Be careful with the volume, that amp will destroy those speakers.

you act like that is a bad thing.

[basscooker]

Originally Posted by modulusman

you act like that is a bad thing.

indeed. IMHO you're downgrading the amp using behringer.

[DBCrocky]

Think of the power rating as a way to rank an amp's loudness. Your 700w@4ohm amp is louder than a 400W@8ohm amp (running the same speakers in the same room, etc).

However, the same is not true with speakers. A 4ohm speaker is not necessarily louder than and 8ohm speaker. Speaker efficiency will affect perceived speaker loudness, as do the shape and porting of the cab, the properties of the room it is auditioned in, and probably other variables as well.

Think of the Ohm rating of speakers as being for making sure you don't blow up your amp. You should never run it at less than the rated load, which for your amp is 4 ohms. So, since you have an 8ohm cab, means you can add another 8ohm cab in parallel and you'll be OK. If you had a 4ohm cab, you could not add a second cab (at least not in parallel...).

[billfitzmaurice]

Originally Posted by DBCrocky

Think of the power rating as a way to rank an amp's loudness. Your 700w@4ohm amp is louder than a 400W@8ohm amp (running the same speakers in the same room, etc).

Not necessarily, and that's where the fallacy of going to a lower impedance load 'to get all the watts out of my amp' lies. How loud a cab can go is a matter of the cabs sensitivity, frequency response and driver excursion limits. The driver excursion limit is particularly crucial, as once that limit is reached additional power applied won't make the cab go one bit louder. And what no cab company will tell you is that their cabs may reach that excursion limit at 1/2 their rated power, if not less.

[MuzikMan]

Not that Bill needs my backup but I think it is worth re-stating that once a driver's excursion limits are reached it will not get any louder no matter how many watts you throw at it.

MOST COMMERCIAL CABS reach their excursion limit far below their thermal rating.

[gumtownbassman]

Originally Posted by MuzikMan

Not that Bill needs my backup but I think it is worth re-stating that once a driver's excursion limits are reached it will not get any louder no matter how many watts you throw at it.

MOST COMMERCIAL CABS reach their excursion limit far below their thermal rating.

To put it in more simplistic terms, generally "you get what you pay for".
Don't be disappointed if your Behringer speakers blow.

[GrowlerBox]

Originally Posted by gumtownbassman

Don't be disappointed if your Behringer speakers blow.

I'm sure they already blow ...

[Rick Blanc]

Originally Posted by GrowlerBox

I'm sure they already blow ...