ohm ratings?????

bassben12 · #1 01-30-2011, 11:28 AM

I guys,

If I have a head thats rated for 300w @ 8ohm and 500w @ 4 ohm and my cab is an 8ohm cab, that means that I will only ever get 300w out of my head right? Would I then need a 4ohm cab to get the full 500w?

Thanks guys a bunch

phmike · #2 01-30-2011, 11:29 AM

Or another 8ohm cab added to what you already have so the total ohms = 4

steamthief · #3 01-30-2011, 11:50 AM

2x8=4

Billy3000 · #4 01-30-2011, 11:52 AM

Quote:

Originally Posted by phmike

Or another 8ohm cab added to what you already have so the total ohms = 4

Is that the case? I've been considering selling a few things including my Mesa Powerhouse 1000 (it's just too big for me to move it myself) and getting an Orange 410 and 115. They're both 8 ohms, if I run my 4 ohm ampeg into them will that be right?

BassmanPaul · #5 01-30-2011, 12:04 PM

You'll do better with a pair of 4x10s rather than the poor mix of a 4x10 and 1x15.

Billy3000 · #6 01-30-2011, 12:44 PM

I like the mix of a 4x10 and a 1x15. That's not really what I'm debating right now. That mix has served me very well in my powerhouse for years now. And all my favorite bassists lately have been trading their 8x10s for a 4x10 and 1x15. It may not be popular on here, but I know what I like.

The only thing I'm asking about is whether or not the 2 8 ohm cabs will work with my 4 ohm head.

AdamR · #7 01-30-2011, 12:53 PM

Yes, two 8 ohms cabs equals a 4ohm load.
If you had two 4ohm cabs it would equal a 2ohms load

So if you want to use the 500 watt rating you will need either one 4ohm cab or two 8ohm cabs

will33 · #8 01-30-2011, 12:55 PM

Quote:

Originally Posted by Billy3000

I like the mix of a 4x10 and a 1x15. That's not really what I'm debating right now. That mix has served me very well in my powerhouse for years now. And all my favorite bassists lately have been trading their 8x10s for a 4x10 and 1x15. It may not be popular on here, but I know what I like.

The only thing I'm asking about is whether or not the 2 8 ohm cabs will work with my 4 ohm head.

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GrowlerBox · #9 01-30-2011, 10:53 PM

With respect to your initial question regarding the advantage of a 4 Ohm cabinet over an 8 Ohm cabinet -- if they are in other respects equal, there's no real advantage. The difference in volume produced through the same cab at 300 and 500 W is marginal, assuming the speakers can even handle the increase in power. The 4 Ohm cab just means you lose the flexibility of being able to add a second cabinet (assuming a head with 4 Ohm minimum impedance) -- more speakers is where the extra volume happens. Unless you add a 1 x 15 to a 4 x 10, of course

kosmicwizard · #10 01-31-2011, 12:30 AM

Quote:

Originally Posted by Billy3000

I like the mix of a 4x10 and a 1x15. That's not really what I'm debating right now. That mix has served me very well in my powerhouse for years now. And all my favorite bassists lately have been trading their 8x10s for a 4x10 and 1x15. It may not be popular on here, but I know what I like.

The only thing I'm asking about is whether or not the 2 8 ohm cabs will work with my 4 ohm head.

This is just an observation but I would rather wheel the powerhouse than deadlift a 4x10 and a 1x15 in two different trips ... Your powerhouse is already a 4x10 and a 1x15 in the same box, the 4x10 is 8 Ohms and the 1x15 is 8 Ohms so it will work exactly the same way. Cheers.

Billy3000 · #11 01-31-2011, 10:06 AM

Quote:

Originally Posted by kosmicwizard

This is just an observation but I would rather wheel the powerhouse than deadlift a 4x10 and a 1x15 in two different trips ... Your powerhouse is already a 4x10 and a 1x15 in the same box, the 4x10 is 8 Ohms and the 1x15 is 8 Ohms so it will work exactly the same way. Cheers.

That's something that I've thought about too. I like how easy it is to move the powerhouse. The problem is that I live in Atlanta, and my former band is in Raleigh, NC. And I don't think that I can fit the powerhouse in the backseat of my little subaru impreza.

billfitzmaurice · #12 01-31-2011, 10:25 AM

Quote:

Originally Posted by bassben12

, that means that I will only ever get 300w out of my head right?

Moot. How many watts your amp can produce and how loud you can get are only peripherally related.

BassBob1 · #13 01-31-2011, 10:27 AM

Above one 4 ohm or 2 8 ohms= 4 ohm etc has been covered well so I will add to the volume issue. The difference in volume is most definitely dependent on the the cabinet design/configuration just as much as the ohm rating. IME a cab at 4 ohms is not that much louder than the same exact cab in an 8 ohm configuration. I played this past weekend my ampeg svt 7 pro thru a mesa PH212 8 ohm and compared to my 410HLF 4 ohm. With the mesa i had to have my amp volume at about 11 o'clock for the same volume I would get around 8:30 on my HLF. I think a good amount of that volume difference can be attributed to the different speaker sizes a little more than the ohm rating. I think that makes sense?

kosmicwizard · #14 01-31-2011, 10:40 AM

Yes this makes a lot of sense. Might I add that, a 2x12 is only 24 inches, a 4x10 is 40 two 2x12's would blow that HLF out of the water, but a lot of that depends on the way you amp is EQed. IIRC, the MESAs have a bit of a low mid spike, the HLF is low! Cheers.