a little bass amp question...

[Captain P?l]

yo!

i just purchased the Gallien Kreueger 700rb-II from ebay, so all i now need is some cabs..
and i know tis guy selling acouple of Trace Elliot cabs, but they are somewhere between 300 and 350 watts...
would there then be a problem for the cabs to be runned by the 480w &8ohm and 350@4ohm cab?



Edit: THANKS for any help at all!

[Miz]

The cab you use has to match the impedance of the amplifier. So if the amp has an 8ohm output, then you need an 8 ohm cab.
You should also get a cab which can handle the maximum power the amp can put out because of the obvious danger of blowing your speakers.

So in short, don't plug a 4ohm 350W cab into a head which puts out 480W @ 8ohms.

[Captain P?l]

yeah.. but the cab is 480W @ 8ohm and 350w @ 4

so i guess i dont have to worry about that?

anyways, i talked to someone else, and they said it wont really matter as long as i dont turn the volume up too much.. i'll hear when the cab is getting to much power... :p


also: i want to use the bi-amp, and for that i use the Speak-on cable, but does the cab have to hae that bi amp swicht? i saw the GK cabs had, but not Ampeg and others...

GK is impossible to get a hold of here in norway, and im not buying cab's over ebay... FUI

[Genesis]

anyways, i talked to someone else, and they said it wont really matter as long as i dont turn the volume up too much.. i'll hear when the cab is getting to much power... :p

I'm not sure about this, but this is what I know: The amp impedence rating has nothing to do with the volume your cab can handle. It's the load the amp's transformer expects at the output end. If u don't match the impedence, u could blow ur output transformer, resulting in one *expensive* repair job.

If somebody could confirm my post... 

[Skeba]

I'll do that...

Though I've only studied electronics for so many years.. If I saw an output that said 8 or 16 ohms at back, that's what I'd think the amp needs for it's load. You can play an 8ohms output through a 16 ohm cab... Just don't do it the other way around... Some bad shit might happen.

If you put 2 of them 4 ohm speakers in a series though, you'd get a nice result.. Just don't connect them parallel to each other..

[Captain P?l]

They deliver 700W/480W into 4
Ohms. Lower impedances should not be used.
Higher impedances such as 8 Ohms, 16 Ohms, or No
Load are acceptable. One 8 Ohm cabinet is okay. One
4 Ohm and one 8 Ohm is not recommended.

ok, so i can use the cab's..

BUT then i cant use a 4 ohm and 8 ohm?!
how do they mean it? can i parralell conect them or serie's connect them?
cuz the cab's are one 8 ohm (4x10) and one 4ohm (1x15)..

[Skeba]

Well, it is not recommended since the cab with the lower resistanse (4ohms) would take most of the current if you put them in parallel... In series, the effect shouldn't be as catastrophic, since they will both have the same amount of current going through them. The reason that it propably isn't recommended is that it might sound shitty. The 8 ohm cab requires more 'heat' from the amp to function properly, than the 4 ohm one. So the reason is propably that they would sound very uneven, and different from one another. 12 ohms combined could mean that you don't get enough power from the amp.

And do not go connecting them parallel.. It'd drop the combined impedancelevel to about 2,6 ohms... And as you said in the earlier post, no lower impedances than 4 should be used. Could end up hurting the amp real bad.

What you could do, is put 2 8 ohm speakers in parallel, when it'd end up being 4 ohms combined.. But you'd have to make sure that your amp can provide enough power to the speakers.

I'd just go with the cab that sounds better and play with one...

[Johnny Rattlesnake]

Your asking the question at the wrong board.
http://www.gallien-krueger.com/community_board.html
Try that one.

[Genesis]

Some articles:

http://www.basslessons.com/webboard/ab_messages/3208.html
http://www.harpamps.com/transformers.html

[Captain P?l]

aha!
thanks guys!
i finally get it!

damn... and i actully went 3 years of electronics school! well, im blonde....

thanks a bunch! from the heart!!


gotta love this board...

[Captain P?l]

now, im gonna bug you a little more...
i found this chart at Eden-electronics' home site:

 Parallel speaker configurations Total system impedance

Two 8 ohm cabinets 4 ohms
One 8 ohm cabinet and one 4 ohm cabinet 2.6 ohms
Two 4 ohm cabinets 2 ohms
Three 8 ohm cabinets 2.6 ohms
Two 8 ohm cabinets and one 4 ohm cabinet 2 ohms
One 8 ohm cabinet and two 4 ohm cabinets 1.6 ohms

When you connect speakers in series, the load decreases as shown below:
Series speaker configurations Total system impedance

Two 8 ohm cabinets 16 ohms
One 8 ohm cabinet and one 4 ohm cabinet 12 ohms
Two 4 ohm cabinets 8 ohms
Three 8 ohm cabinets 24 ohms
Two 8 ohm cabinets and one 4 ohm cabinet 20 ohms
One 8 ohm cabinet and two 4 ohm cabinets 16 ohms


so, my new question is:
does series connecting them make it sound worse?
im just curius if anyone has tried it..

and i though i just might post it here for later use too...