#1
So i know that the cab ohm rating has to be either equal or higher than the head rating. But i'm looking at getting an Orange Terror Bass 500w head, which has a switch in the back that can switch between 4 and 8ohms. When i get a cab to match, which would be best(ohm rating, not brand)? Does using a 4 ohm match sound different than an 8, or is it for something like multiple cabs?
#2
To quote the FAQ:

Ohms – They’re the impedance of the cabinet and it will say what the ohm rating is. The head will require a match between the ohms of the cabinets and the ohms that the head itself produces in order to get the highest output but we’ll worry about that later. For now, you need to be more than or equal to the minimum ohm rating given on the amp. This tends to be 4 ohms, although 8 and 2 ohm amplifiers exist.

For example, our amp produces 100% of it's output at 4 ohms. This means you can connect an 8ohm cabinet or a 4ohm cabinet and have no trouble. 4ohms would be where the amp is most efficient and have the greatest output. If you used 8ohms, the output will be reduced down to the region of 60%.
You can use two 8ohm cabinets to draw the full output from the head however. To do this you would wire them up in parallel, using both the speaker outs on the back of you head. If you were to have them in series, their impedance would be 16ohms and would only draw about 30-40% of the output of the head.

As your head is 4ohm minimum you must not wire speaker cabinets which would give you 2ohm draw. This would force the amp to work over its rating; it could over heat; start a fire; burn your house down; kill your kitten and you’d have no bass amp to play on. 2ohms could be achieved by wiring two 4ohm cabs in parallel so if you want a full stack with two cabs, go for 8ohm cabs to be on the safe side.
#3
Yeah i read that first and it helped, but as of right now i can only afford the head and one cab. So am i better off buying one thats 500w at 4ohms or 500w at 8ohms? Because the head can handle both, so is there a benefit to one or the other?
Last edited by dosvidanya92 at Dec 6, 2011,
#4
It all comes down to what you are looking for in configurations as far as cabinets are concerned, esp. if you are looking towards multiple cabs.

Now there are some who will swear on their grandmother's grave they can hear a tone difference along with a volume difference between 4 and 8 but if there is one, its minimal to most hearing.
#6
Quote by anarkee
It all comes down to what you are looking for in configurations as far as cabinets are concerned, esp. if you are looking towards multiple cabs.

Now there are some who will swear on their grandmother's grave they can hear a tone difference along with a volume difference between 4 and 8 but if there is one, its minimal to most hearing.



I'll add that, because any audible difference that may or may not exist is so minimal, there's no good reason to not get the 8ohm if they're comparable. You may not be planning on getting a second cab now, but you never know if the fancy might come up down the road--the 8 leaves you more options in the long run.

Most objections will be those claiming the volume difference is considerable because the SS amp will usually put out less wattage at 8ohms than 4ohms. I don't personally think it makes enough of a difference to be a consideration.
#7
In the sense of running say a 500w @ 4 ohm & 350w @ 8 ohm amplifier.

wouldnt it then make sense that the head running at 500w there for has more power to run louder. And i know watts does not equal volume level but say i run my 8 ohm GK quad, I have my volume at say 5 to play with my band and have enough volume to keep above the drummer while if i use my 2 2x10 GK boxes side by side which then runs the head at 4 ohms I only have to turn up to say 2-3 to still be at the same perceived volume level. and for another Example I can run my quad at home on 3 and my amp kicks in properly and it sounds great, with the 2x10's by the time im getting to a volume where the amp sounds good... its too loud at 2 volume so I choose to run my quad at 8 ohms at home rather than 2 2x10's at 4 ohms with the exaxt same head.

So my idea would be that a quad at 8 ohms does not equal a quad at 4 ohms because of the power supplied by the head increases.

But back on track, I enjoy the idea of 8 ohm cabinets and running multiple cabs to bring it down to 4 ohms. say an 8 ohm GK or dave eden cab vs a 4 ohm GK or dave eden cab.. well the only difference really when it comes down to it is how much gear you want to lug and if you want to go 2 cabs or a 1x15 and if your thinking a single quad is more than enough, than an 8 ohm is still perfectly fine. As I said, I can't turn up my amp at 4 ohms at home to sound good enough but then again Im running a 700w SS amp, with something like a 250w SS amp im sure there is a lesser difference.
#8
8 ohms will give you more cab options as stated above
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