class AB vs D (not the usual question)

[ultimate157 5,000+ posts]

I realize that class AB's have higher sound quality than class D amps. Class AB are less efficient than class D.

But if we are talking only 800w RMS, will a class AB put a much larger strain on the electrical system of the car it is running on vs a class D. As in real-world noticable?

The reason I ask is because my alternator isn't as strong as it used to be. on 400w RMS between two class AB amps my lights dim a little. I will be upping that to 1000w RMS (-200w + 800w) and it'd be nice to get a class D vs a class AB if its going to not strain my system as bad.

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[phyphoestilic 5,000+ posts]

It's possible to get a really ineffective class D, but chances are a class D will be better on the electrical

 

[ultimate157 5,000+ posts]

Typical class D efficiency at rated output = 75%Typical class A/B efficiency at rated output = 60%

800/(0.6*14.4) = 92.6 amperes

800/(0.75*14.4) = 74.1 amperes

You'd be looking at about 20 amperes less peak current draw ...

i'd say that a pretty significant difference.... Thanks guys.

 

[thch 10+ year member]

even better is that the class D keeps a fairly high efficiency even at lower power outputs. class AB does not do this.

 

[supa_c 5,000+ posts]

Typical class D efficiency at rated output = 75%Typical class A/B efficiency at rated output = 60%

800/(0.6*14.4) = 92.6 amperes

800/(0.75*14.4) = 74.1 amperes

You'd be looking at about 20 amperes less peak current draw ...

I must have some super amps then.

My sub amp is rated at 350W@2ohms RMS @13.8V

It has a 20A fuse

If you do the basic math its over 120% effecient....//content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

Its not cheap junk either //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[luvinthebass 5,000+ posts]

I must have some super amps then.My sub amp is rated at 350W@2ohms RMS @13.8V

It has a 20A fuse

If you do the basic math its over 120% effecient....//content.invisioncic.com/y282845/emoticons/eek.gif.771b7a90cf45cabdc554ff1121c21c4a.gif

Its not cheap junk either //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

hmm is that the Alpine m350 model?

 

[phantom240 5,000+ posts]

lol. y amp must be **** efficient for an AB, its an alpine MRV-1507, rated RMD at 14.4v is 900w bridged at 4ohms, and has an 80 amp fuse on it. I know for a fact it puts out more than that though //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[pwnt by pat 10+ year member]

Fuses will handle higher than their rating for short amounts of time.

 

[supa_c 5,000+ posts]

Slow-blow fuse ...

They are rather beefy.

Still doesnt explain the power though

 

[supa_c 5,000+ posts]

hmm is that the Alpine m350 model?

nope, its way more expensive than that