Concert Bass Head: What Cabs Should I Run?

[BRAILLE]

This is my first ever bass head and I'm very excited about it. The head is rated at 200 watts and 2 OHMs. I've read a few articles on OHMs and wattage but I can't seem to fully understand the concept... I will read a few more articles later but for right now I'm sick of sitting infront of the comptuer. Anyway, I was curious what you'd reccomend I run out of this amp? Would it be possible to run a 1x15 and 4x10? If any of you could reccomend me combos of what I could run out of the amp I'd appreciate it! I would also appreciate it if anyone could post useful websites that have info on OHMs, wattage and DIY cab guides!

Thanks

[Johann]

alright, I'll start this off by saying that while the back says you can run the coliseums at 2 ohms, 4 is probably as low as you should go so as to maintain its lifespan.



now I will try to explain the way ohms work in relation to cabs and amps:

cabs come in three main impedances, 16, 8, and 4 ohms

when you combine two cabinets, you are putting them in parallel 99 times out of 100

this means two 16 ohm cabinets will become 8 total ohms to the amp, 8 becomes 4, 4 becomes 2

when you use odd numbers(other than 1) or mismatch impedances between 2 cabs you have some nice fractional ohm calculations, which I'm sure joe or edbass would gladly post for you, I'll just stick to the basics.




with solid state amplifiers like the coliseum, it isn't necessary to have any particular ohm load, as long as it is above the minumum of 2 or 4 ohms. however the higher you go impedance wise, the lower your output wattage will be.


I think it's been said that at 4 ohms the coliseum bass puts out in the neighborhood of 150 watts, I'm not really sure.


so to sum it up, if you got a 1x15 and a 4x10 that were both 8 ohms, you'd be fine to use them both 

[BRAILLE]

Ahh yes, that explination was very easy to understand.

So what if I had a 1x18 cab that was 8 OHMs but 500 watts? Would that not work because the speakers increadible amount of wattage compared to the head?

If I wanted a 4x10 8 ohm cab and if I were buying individual speakers would each speaker need to be 16 OHMs to mach up to 8 OHMS or could they be 8 OHMs each?



Thanks, I appreciate your help!

[Johann]

the wattage just means how many watts the speaker can handle running through it constantly, that speaker should sound fine with your amp.



when you buy individual speakers for cabs, there are a few ways you can wire them to make them come out the ohms you want

for instance if you want an 8 ohm cab, you would buy four 8 ohm speakers. then you would connect a pair each in series to each other, and connect the pairs parallel, to make 8 ohms collectively. it's kind of hard to visualize just based on that if you are unfamiliar with wiring cabinets, but if you go to the Celestion website they have a section on wiring cabinets that would help you, I'll get the exact link for you in a minute to help clarify.

[Johann]

http://professional.celestion.com/guitar/features/drdecibel/index.asp

if you go to the second drop down box here(under "secrets") and select Wiring Diagrams, that should hopefully clear up any other questions you might have about individual speaker impedance.

[BRAILLE]

Wow that helps a bunch, thank you!

[Johann]

no problem, enjoy your amp 

[Ryanx]

okay now here's my question reguarding this issue. 


i have 2 8 ohm cabs stocked with 8 ohm speakers.  if i re-wire the cabs completely in series would that make 2 32ohm cabs?  and then when run in parallel with each other make a 16 ohm load?

my head won't let me run 4 ohms and i need to situate something before i can replace all 8 speakers.

[ryanowens]

Correct,
4 8 ohm speakers in series gives you a 32 ohm cab.
Running two of them parallel gives you a 16 ohm load.

Honestly though, I would suggest looking into more efficient speakers (which has been mentioned in the past).  I used to run a Coliseum Lead (into a Beta 402) & Coliseum Slave (into a 4x10 cab I loaded with 108g Transducers) before I snagged a Beta Lead which I use with only the 410.  Speakers which compliment your head/are very efficient work out much better (and louder) than just daisy chaining to oblivion for a wall of sound.  Basically, work smarter not harder for your tone.

[Isaac]

okay now here's my question reguarding this issue. 


i have 2 8 ohm cabs stocked with 8 ohm speakers.  if i re-wire the cabs completely in series would that make 2 32ohm cabs?  and then when run in parallel with each other make a 16 ohm load?

my head won't let me run 4 ohms and i need to situate something before i can replace all 8 speakers.

What kind of head do you have that won't allow you to run a 4 ohm load?

[Ryanx]

orange rockerverb 100

[pickinatit]

http://www.shredmuzic.com/SearchResults.asp?Cat=50&Redirected=Y

This is a pretty good page for speaker wiring & Ohm/impedance
information.