ohms vs sq

[RebelDogg 10+ year member]

I've been reading contradicting reports on this. At first I thought the ohms rating only had to match the amp and the lower the impedance the more power the sub could draw from the amp.

Now I'm reading that higher impedance will give you a tighter bass response. So would a 1000w 8ohm sub with a 1000w 8ohm amp sound better than a 1000w 1ohm sub with a 1000w 1ohm amp?

I like SPL fine, but I'm really more in it for SQ. I listen to a lot of fast bass metal, so I need that tight response. The subs I've been looking at are 1000wrms 2ohm DVC or 4ohm DVC. I was going to get (2) 4ohm subs and an amp rated for 2000w@1ohm. Now I'm not sure.

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[jbizzle 5,000+ posts]

I'm pretty sure there aren't a lot of amps that put out 1000wrms @ 8 ohms, if they do its prolly one expensive amp. there won't be a difference in sound though.

 

[RebelDogg 10+ year member]

I was just using that as an example. But that's what I wanted to know.

This is what started it all:

"Next is the BXi 2006D for an awe inspiring 2000-Watts at 1-Ohm. 1-Ohm, that's no problem, but all our Brutus amplifiers can run at 4- or 2-Ohms as well, for an even tighter bass response!"

link: http://www.hifonicsshop.com/page/1164887

 

[Electrodynamic 10+ year member]

You might be able to tell the difference in major damping factor changes (going from 1 Ohm to 4 Ohm with the same amp), but with smaller changes you probably won't be able to tell.

Make no mistake, I'm talking about a SMALL difference, IF any. It's not a HUGE thing going up in impedance. And for that matter, impedance does not dictate SQ. If you took sound quality on a 100% scale, damping factor makes up

...and that quote is just marketing BS.

 

[helotaxi 5,000+ posts]

Total BS. The difference that they're talking about is one of damping factor. Any amp worth owning will have adequate damping at any impedance into which it is stable. Once damping factor is adequate, going higher gains you no audible benefit.

 

[SethPhillips 5,000+ posts]

yes raiseing/ lowering the damping factor will have a very small change in sq... like Electrodynamic said...

my vr2000d will put out 1000w at 4 ohm.... but i want all 2000w so i choose 2 ohm...

unless it's a stricly competition car/system.. then i will run 1 ohm and under...

 

[azimuth 5,000+ posts]

i've got a single type R running at 8 ohms on a pc2350. it's around 750 rms at 8 ohms. i can't hear a difference from when i had 2 running at 4 ohms.

 

[dman4486 5,000+ posts]

i've got a single type R running at 8 ohms on a pc2350. it's around 750 rms at 8 ohms. i can't hear a difference from when i had 2 running at 4 ohms.

nice amp, but are you sure you are getting 750 at 8 ohm? bench test?

 

[azimuth 5,000+ posts]

nice amp, but are you sure you are getting 750 at 8 ohm? bench test?

it does a little over 1500 at 4 ohms. i really don't know what it does at 8 ohms, but i'd bet it's around 750. it murders my single type r at 8 ohms, so it puts out a decent amount at 8.

 

[dman4486 5,000+ posts]

it does a little over 1500 at 4 ohms. i really don't know what it does at 8 ohms, but i'd bet it's around 750. it murders my single type r at 8 ohms, so it puts out a decent amount at 8.

set it with an o-scope, then test output with a dmm to figure out the wattage....there will be no more questions of "how much am I really getting"

 

[azimuth 5,000+ posts]

set it with an o-scope, then test output with a dmm to figure out the wattage....there will be no more questions of "how much am I really getting"

it's a very temporary setup. i wanted to run 1 12 ported instead of the 2 sealed i had before. very soon, i'll be getting a bigger 12 to replace the type r. running at 8 ohms is only out of neccesity.

 

[dman4486 5,000+ posts]

it's a very temporary setup. i wanted to run 1 12 ported instead of the 2 sealed i had before. very soon, i'll be getting a bigger 12 to replace the type r. running at 8 ohms is only out of neccesity.

ah...

 

[rc10mike 10+ year member]

Zapco seems to think that higher ohms = better sq.

Personally, I ran my JL w6v2's with 1000 @ 1 and then 1000w @ 4ohms on a different amp, an I could tell a difference, It sounded better, more precise and musical. You just have to know what to listen for. A good way to test this out is to play a song you've heard MANY, MANY times.

Was is a huge enough difference to make me want to run everything at higher ohms? No, not really.

 

[2critical 10+ year member]

Total BS. The difference that they're talking about is one of damping factor. Any amp worth owning will have adequate damping at any impedance into which it is stable. Once damping factor is adequate, going higher gains you no audible benefit.

x 100000000

 

[squeak9798 5,000+ posts]

yes raiseing/ lowering the damping factor will have a very small change in sq... like Electrodynamic said...

As helotaxi pointed out, DF isn't a "higher is better" spec and you will not hear differences between DF when kept outside of the range where it has audible effects (i.e. anything above ~20). The only way you'd hear a difference is if you crossed that line where DF is low enough to cause an audible change. Not many amplifiers on the market will cross this line when operated within their intended range.