4 ohms, 1,000+

[solidcrowd 10+ year member]

it will put less strain on your elecrical system if your amp runs at a higher impedance than its lowest rating for example a class d at 1 ohm will pull more than the same class d at 4 ohms usually.

do u know how much more it pulls? or is it noticable?

 

[dB-r 10+ year member]

Just go back and look at my math example. All Class D amps should be in the 80%-95% range. Those with higher rail voltage will probably be most efficient.

 

[RydHy3845 10+ year member]

I thought class d's are usually in the 70-80% effecient range and class ab in the 60's%

 

[JimJ 5,000+ posts]

All Class D amps should be in the 80%-95% range.

At full power at a low impedance, that's an extremely optimistic range.

 

[squeak9798 5,000+ posts]

do u know how much more it pulls? or is it noticable?

It will have less current draw because it is outputting less power. So yes, it's noticeable...but so is the substantially decreased output. Barring amplifiers like the PG Xenon and JL Slash; An amplifier operating at 1ohm will output approximately 4x what it's capable of at 4ohm. So sure there is going to be a substantial difference in current draw, along with power output.

If you are looking for efficiency, just look for a mono class D amplifier and forget about finding an amplifier to output the power you need into 4ohms. Most amps that fall into your price range and output that power into 4ohms are going to be class A/B and have significantly more current draw than a class D of similar power operating into a 1ohm load.

At full power at a low impedance, that's an extremely optimistic range.

I would have to agree.

 

[dB-r 10+ year member]

He is just confused, someone told him to only run 4 ohms to save his battery and electrical system some stress. They didn't explain that 1000 watts is 1000 watts no matter how you get it, Class AB or Class D. Class D is more efficient.

And 80-95% efficient for class D is no more optomistic than 60% for AB right? Working off theory here, just an example.

 

[squeak9798 5,000+ posts]

And 80-95% efficient for class D is no more optomistic than 60% for AB right?

Not really.

Not uncommon for a class A/B running at full power to be above 60% in efficiency.

Here's just a few examples;

http://carsound.com/articles/publish/article_150.shtml

http://carsound.com/articles/publish/article_298.shtml

http://carsound.com/articles/publish/article_31.shtml

1/3 power the story is a little different, sure. But that's one of the disadvantages of the topology.

OTOH, it's pretty rare for a class D to be >85% efficient, especially into anything other than a 4ohm load.

Working off theory here, just an example.

Which is fine and well....except those newer to the technical side of audio will take those figures as literal and expect to get 90%+ efficiency out of their class D.

 

[dB-r 10+ year member]

What about Class D running at half load or less? What efficiency has been measured/theorized?

getting off topic here. 1000 watts at 4 ohms draws the same current as 1000 watts at 1 ohm on the same amp.

 

[squeak9798 5,000+ posts]

What about Class D running at half load or less? What efficiency has been measured/theorized?

What do you mean by "half load"?

Are you talking impedance, or power output?

If impedance..."half" of what?

If you are talking power output.....they won't have the substantial drop in efficiency like a class A/B will...but they are still typically no where near the #'s you projected.

getting off topic here. 1000 watts at 4 ohms draws the same current as 1000 watts at 1 ohm on the same amp.

Theory is great.

Reality is a kick in the nuts.

PG Xenon; Outputs approximately the same power into loads from 4ohm to 1ohm. Gander at the efficiency at those respective loads;

http://carsound.com/articles/publish/article_413.shtml

 

[RAM_Designs 5,000+ posts]

Massive Audio P3000.1, 1500 at 4ohms, got mine for $450 shipped off of ebay...just an option

 

[CaliforniabOY5 10+ year member]

Good luck on this. I think you're going to end up with a Class A/B bridged. Hope you have a beefy electrical system.
http://www.woofersetc.com/index.cfm?fuseaction=product.display&Product_ID=3179

Probably the closest you'll get. Have yet to see one of these big ones on eBay.

thats VEry impressive!

 

[Diplexers 10+ year member]

THIS ONE!!!!//content.invisioncic.com/y282845/emoticons/graduate.gif.d982460be9f153bb54e5d4cb744f6ae8.gif

PPI PC2350 1400 @ 4 ohms

http://cgi.ebay.com/PRECISION-POWER-AMPLIFIER-PC2350-POWER-CLASS_W0QQitemZ230114285930QQihZ013QQcategoryZ18796QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

 

[dilligaf241 10+ year member]

might wanna look at this

http://www.caraudio.com/forum/showthread.php?t=226339

 

[azimuth 5,000+ posts]

THIS ONE!!!!//content.invisioncic.com/y282845/emoticons/graduate.gif.d982460be9f153bb54e5d4cb744f6ae8.gifPPI PC2350 1400 @ 4 ohms

http://cgi.ebay.com/PRECISION-POWER-AMPLIFIER-PC2350-POWER-CLASS_W0QQitemZ230114285930QQihZ013QQcategoryZ18796QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

i run that one. i fvcking love it. way underrated. mine is on 2 type R's and the gain is set at under 1/2.

 

[Tacosys 10+ year member]

get the new ALPINE PDX 1000.1. It is 100x1@4 and 2 ohms/