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OHMS

C

CliffBurton1

Dec 13, 2008
35
0
Ohio
#1
Ok, someone can probably answer this quickly.

Lookin at the Peavey Tour 450.
It's 450 watts into 4 ohms...
That's what confuses me. I can only find cabs with 8 ohms.
How many watt cab do i need?
Like, doesn't it split into 8?
Or does it double?
Yeah, I'm confused....


Thanks
 
#3
CliffBurton1 said:
Ok, someone can probably answer this quickly.

Lookin at the Peavey Tour 450.
It's 450 watts into 4 ohms...
That's what confuses me. I can only find cabs with 8 ohms.
How many watt cab do i need?
Like, doesn't it split into 8?
Or does it double?
Yeah, I'm confused....


Thanks
Click to expand...

I have no idea what youre trying to ask. Are you trying to pair it up with another cab? What kind of amp head are you plugging these speakers into?

EDIT: nevermind, i get it, I thought Peavey tour 450 was a cab


to get a 4 ohm load out of an 8 ohm cab, you must get 2x 8 ohm cabs i believe.
 
#10
I think I'm even more confused now. Say you have a Peavey Tour 450 head. It's output is 450 watts into 8 ohms. Now take the:
Peavey Tour VB-115 350W 1x15 Bass Speaker Cabinet Features:

* 700 watts program power handling; 1400 watts peak
* 15" 1502-8 classic Black Widow bass woofers
* 8 ohms impedance
So you have 1 speaker and the speaker is rated at 8 ohms. So the formula is 1/8=.125 so it wouldn't work?
Now take 2 of the same cabs...2/4+4=2/8=4 ohms. ??
Ok...then 2 4ohm cabs: 2 cabs/2+2=2ohms?
Or is it...2 cabs/8 ohms + 8 0hms= 2/16= 8 ohms.
And 2 4 ohm cabs is...2 cabs=4+4= 2/8 = 4 ohm.
Sorry, I'm dense...I'm trying.
 
#12
dmot002 said:
Two 8ohm cabinets will give you 4ohms of draw. That said, your peavey head will now give you 450 watts of power at 4ohms with two 8ohm cabinets. Or you could find a cabinet that is 4ohms.
Click to expand...

So it's....2 cabs @ 8 ohms each, you just use 8 ohms as a factor because both speakers are the same impedance. So 8 ohms/2(# of speaker)= 4 ohms?
Also...1 cab @ 8 ohms would be 8 ohms/1(#of speakers)=8 ohms?
I hope I'm getting closer...whew!
 
#13
UncleBalsamic said:
This may help: http://www.talkbass.com/forum/showthread.php?t=166225
Click to expand...

Actually this will do more than just help.

The people that put together the various FAQ's have done an excellent job of compiling the answers to most questions in an easy to understand format. Take just a few minutes to review the above link, then if you have some answers almost everyone on this forum will be more than happy to help you.

Hope this helps.
 
#14
dmrogers said:
Actually this will do more than just help.

The people that put together the various FAQ's have done an excellent job of compiling the answers to most questions in an easy to understand format. Take just a few minutes to review the above link, then if you have some answers almost everyone on this forum will be more than happy to help you.

Hope this helps.
Click to expand...

Done read it....that's why I'm asking now. Sorry. I think I may have it now. Was my last post right?
 
#16
Ray Salamon said:
You're last post was explained EXACTLY in the FAQ linked. Ohms law is spelled out right in it, all you have to do is put in the numbers that are relevant to you.
Click to expand...

I didn't get the part that says if the 2 cabs have the same impedance, say 8 ohms, use that number(8) and divide by the number of speakers. Plus the part that had 3/16 = 5.3333 ohms. I figured out it should actually be 16/3. Thanks though...it is a good thread.
 
#17
mello_bedwetter said:
I didn't get the part that says if the 2 cabs have the same impedance, say 8 ohms, use that number(8) and divide by the number of speakers. Plus the part that had 3/16 = 5.3333 ohms. I figured out it should actually be 16/3. Thanks though...it is a good thread.
Click to expand...

Yes, when all of the cabinets are the same impedance, then it is relatively simple. If you have cabs with different impedance, it is best to use this equation:

Total impedance = 1/(1/a + 1/b + 1/c ... + 1/n)

There are other ways to do it, but honestly if you don't understand impedance/resistance and are not good at math, it's best to use the equation above. It works.

For instance:

IvanMike said:
With a 4 ohm cabinet and an 8 ohm cabinet run in parallel the formula is 1/(¼+1/8). You can’t add ¼ to 1/8 without having the same denominator (I told you this was gonna sound like school), so you have to reduce ¼ to 2/8 so they match. Then adding 2/8 to 1/8 gives you 3/8, dividing 8 by 3 gives you 2.67. So, hooking up an 8 ohm cabinet and a 4 ohm cabinet in parallel to your amp gives the amp a load of 2.67 ohms to power.
Click to expand...
 
#18
mello_bedwetter said:
I didn't get the part that says if the 2 cabs have the same impedance, say 8 ohms, use that number(8) and divide by the number of speakers. Plus the part that had 3/16 = 5.3333 ohms. I figured out it should actually be 16/3. Thanks though...it is a good thread.
Click to expand...

It does not matter how many speakers are in the cabinet. If the cabinet says that it is a 8ohm cabinet it is 8ohms. Example , You could order a Mesa Powerhouse 8 x 10 cabinet in a 8ohm version or a 4ohm version .

http://www.mesaboogie.com/Product_Info/Bass_Cabs/VINTAGE-PowerhouseCABS/VinPHbass8x10-LG.htm
 

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