New Bassist simple question (ish) :)

nosniktar · #1 09-23-2010, 06:23 PM

Hey Guys/Girls

I am a reasonably new bassist and I'm running a Line 6 HD750.
I decided to build a cab so i've made a 4x10 running Eminence woofers each rated at 8ohms.

So i did my research and decided to wire the cab in series and parallel as my head takes a single cab of 4ohms or above.

However when it came to wiring all intelligent thought went out of the window and i wired it straight up parallel. Which ultimately means the cab is rated at 2ohms

So heres the thing i've only just realised and i played the cab on tuesday and it sounded awesome.

There was no over heating of the head (didn't even get warm) and nothing blew (phewww)

SOOOOOO do i rewire and sacrifice wattage or as my head seems to be handling the lower impedance with no adverse side effects do i carry on with the 2 ohm??

Any thoughts would be gratefully received, as i say i'm a new bassist and although i understand the concept, nothing replaces experience!!

Thanks in Advance

Sartori · #2 09-23-2010, 06:37 PM

Get a new head.

nosniktar · #3 09-23-2010, 06:40 PM

Thanks for the constructive input, much appreciated!

tsunami1052 · #4 09-23-2010, 06:46 PM

If the head is rated @ 4ohms & 8ohms, I would not run it @ 2ohms for long.

http://www.avatarspeakers.com/wiring%20diagrams.htm

bassplayerbob · #5 09-23-2010, 06:48 PM

Rewire the cab as a 4 ohm. Maybe nothing happened yet, but it most likely will!!

nosniktar · #6 09-23-2010, 06:49 PM

Hi Tsunami thanks for the reply, my understanding is that the lack of resistance a 2ohm cab would provide would lead to an overheating of the amp and therefore damage to the tubes etc... As this is a solid state amp and doesn't appear to be overheating would the same apply?

nosniktar · #7 09-23-2010, 06:51 PM

Hi Bob, how would I rewire 4 8ohm speakers to produce a 4ohm load, from all the research I've done this doesn't seem a possibility!?

Sartori · #8 09-23-2010, 06:52 PM

I'm only being half serious, I just dislike line 6 products.

However, your choices here are pretty simple. You have to rewire the cab so that it's no longer 2 ohms, or get a head that supports a 2 ohm load. I'd rewire the cab at the very least, as you can't add another cab to the rig if the first one is 2 ohms. Running the head at 2 ohms might not hurt it in the short term, at low volume levels, but turning it up or playing it for long could damage it.

nosniktar · #9 09-23-2010, 06:54 PM

Hey Satori, it's early hours here no offence taken or intended!!
I'd happily rewire if I could work out how to make it a 4ohm cab I don't want to lose the wattage inherent to wiring it as an 8ohm, (according to line 6 literally 50%)

Sartori · #10 09-23-2010, 06:58 PM

50% less wattage does not translate to 50% less loud.

If you wire it to 4 ohm, and you decide to get another cab, you will then be running into the same problem if your head is not supposed to do 2 ohms.

nosniktar · #11 09-23-2010, 07:01 PM

The cab I've made is rated at 1200W it totals 11ft3 and took six tuning ports, it's honestly ridiculously loud (but as a project I wanted to push it) I'm reasonably certain that I won't be adding another cab anytime soon. So if anyone knows a way to wire 4 x 8ohm as 4ohm load you'd honestly make my day

nosniktar · #12 09-23-2010, 07:02 PM

That was 11 foot cubed not 11ft 3inches lol

jazzblade · #13 09-23-2010, 07:15 PM

Quote:

Originally Posted by tsunami1052

If the head is rated @ 4ohms & 8ohms, I would not run it @ 2ohms for long.

http://www.avatarspeakers.com/wiring%20diagrams.htm

+1 the way to go

Bass_Pounder · #14 09-23-2010, 07:20 PM

Just re-wire the cab.................

No - it CANNOT be made into a 4 ohm cab. You are stuck with either 8 ohms or 2 ohms. The 2 ohm option will eventually coax your head to give up the magic smoke.

Running at 8 ohms (even with a power drop of 50%) only translates to a loss of 3db.

nosniktar · #15 09-23-2010, 07:22 PM

So using my limited (school knowledge) of circuits and wiring is it not possible to wire in two ressistors to bump the impedance to 4ohms?

magic papa · #16 09-23-2010, 07:28 PM

Quote:

Originally Posted by nosniktar

Hey Guys/Girls

I am a reasonably new bassist and I'm running a Line 6 HD750.
I decided to build a cab so i've made a 4x10 running Eminence woofers each rated at 8ohms.

So i did my research and decided to wire the cab in series and parallel as my head takes a single cab of 4ohms or above.

However when it came to wiring all intelligent thought went out of the window and i wired it straight up parallel. Which ultimately means the cab is rated at 2ohms

So heres the thing i've only just realised and i played the cab on tuesday and it sounded awesome.

There was no over heating of the head (didn't even get warm) and nothing blew (phewww)

SOOOOOO do i rewire and sacrifice wattage or as my head seems to be handling the lower impedance with no adverse side effects do i carry on with the 2 ohm??

Any thoughts would be gratefully received, as i say i'm a new bassist and although i understand the concept, nothing replaces experience!!

Thanks in Advance

Whether the amp supports 2 or 4 ohm depends on its heat dissipation ability. Many amps rated at 4ohm can operate with 2ohm for short period of time or at low volumes.

I don't think you will experience any problems until you crank it up. Not sure about Line6 but some amps would have protection circurits bult in that should enagage if spearkers draw too much current.

To cut the long story short - I wouldn't run a 2 Ohm cab by the amp that requires 4 or more. There was a reason they rated it at 4, most likely at high volumes the power section starts overheating and can blow up.

Cheers

MP

bassplayerbob · #17 09-23-2010, 07:29 PM

Quote:

Originally Posted by nosniktar

Hi Bob, how would I rewire 4 8ohm speakers to produce a 4ohm load, from all the research I've done this doesn't seem a possibility!?

Look at Diagram 3 on the link provided by tsunami....

Series / Parallel

4 x 8 Ohm speaker = 8 Ohm load
4 x 16 Ohm speaker = 16 Ohm load

nosniktar · #18 09-23-2010, 07:32 PM

Thanks to everyone for the help I will wire it as an 8 ohm cab for peace of mind I just wanted to try to educate myself and you have all helped, Bob I originally put I was going to wire as series/parallel before a brain fart left me with a 2ohm cab

Thanks again to everyone

john m · #19 09-23-2010, 07:33 PM

2 ohms or 8 ohms are your only options. Wire it for 8 ohms.
2 ohms will eventually fry the amp----either with volume or too heavy on the low frequencies.

An 8 ohm cab is fine and you can always run anonther 8 ohm cab (outdoor gigs) in parallel for a 4 ohm load.

FYI resistance is not the same as impedance.

bassplayerbob · #20 09-23-2010, 07:34 PM

Quote:

Originally Posted by nosniktar

Thanks to everyone for the help I will wire it as an 8 ohm cab for peace of mind I just wanted to try to educate myself and you have all helped, Bob I originally put I was going to wire as series/parallel before a brain fart left me with a 2ohm cab

Thanks again to everyone

Brain explosions will doit all the time