Subwoofer amplification...

glemay

Hey guys,

Got a question on subwoofer amplification. Right now we are running a two channel amplifier pushing a 12" pioneer. With this set up the volt meter will show a slight draw when the bass hits. Will we be able to minimize this draw with the use of a class-D amplifier? I hear they are more efficient, but in which way?

Thanks

Jerry

neomagus00

a minor technical clarification: your amp actually draws current, so when you see the voltage sag a little bit like that, that means your amp is drawing more current than your electrical system can handle, and so the voltage drops as the system tries to recover...

to answer your question simply, yes, a class-D will help, because it produces more power for a given current draw, so the same (say) 400 watts will take very roughly 20% less current... if it's a minor problem, a capacitor will help as well, and likely be cheaper than the amp...

1996blackmax

Before you either buy and amp or a capacitor, the best thing to do would probably be the big 3 upgrade.

http://forum.sounddomain.com/forum/ultimatebb.cgi?ubb=get_topic;f=5;t=007801;p=

glemay

Thanks for the replies guys,

The slight voltage drop is not really a big deal. Just so everyone knows, this system is in a boat. It does not happen when the motors are running, the batteries are getting a good charge and all. The amplifier is running off a big class D battery, I think that is what they are called anyway. They are like 24"x12"x12" or so. The slight voltage drop only happens when we are sitting in a bay with the stereo going at a good pass for a good lenght of time. The batteries are on a constant charge, 40+ true amp charger.

As for the big 3 upgrade, I really think its already up to par. Everything in the boat is heavy duty, (big diesels). Plus it would be, at least I think it would be alot of work to "upgrade".

The only reason I am really after a more efficient amplifier for the subwoofer is so that the battery charger is not under as heavy or constant of a load. It all seems to make sense to me anyway.

Thanks

neomagus00

that would make sense, but as long as you don't drop like a volt below nominal, it's no big deal - more than that and your batteries will begin to lose their ability to recharge fully (happened in my car recently)... in your case, a cap wouldn't help, but a class-d would allow you to play longer before getting the drop you're noticing (i assume you're talking long-term, not a momentary drop)... i personally don't think it'd be worth it, but it is your battery charger

glemay

Thanks neomagus00,

Yeah, normally we would have just ignored it but I'm looking for a amplifier for my boat and the one on my dad's boat would be perfect, and he is always up for improving things on his boat. So he will get a new class D amplifer and I will get a pretty good amplifer for my boat.

As for a class D amplifier, how big would we need to go? We are only running one 12" Pioneer Premier, 400 watts RMS and 800 watts peak I believe. Its a single voice coil subwoofer in a ported box. I was looking at something like this here in regards to power:

http://www.futureshop.ca/catalog/proddetail.asp?logon=&langid=EN&sku_id=0665000FS10040348&catid=#

Thanks

neomagus00

try this hifonics amp, instead... cheaper by quite a bit, still an excellent amp, and has an appropriate amount of power...

glemay

Neomagus00,

So are you saying that the amplifier I mentioned is not powerful enough and I should be looking at something with around 400 rms?

Thanks

neomagus00

for a 400 WRMS sub, that would indeed make sense

MacLeod

No, no, no, no. A Class D will still cause a voltage drop. Now granted a Class D will draw less current than a Class A/B to make the same wattage but the difference aint gonna be by much. You hook up a 400 watt A/B amp and a 400 watt D amp and youll still see a voltage drop. And that Hifonics is going to be far more underrated than the Pioneer so that 400 watt amp will likely be making 500 or more and I guarantee ya, youll still have a voltage drop.

If the voltage drop is minor and the guage stays in the "normal operating" range I would sweat it. Unless youre willing to either give up the sub or upgrade the charging system, its something youre gonna have to live with.

audiobliss

MacLeod wrote:

If the voltage drop is minor and the guage stays in the "normal operating" range I would sweat it.

I'm fairly sure that "would" is supposed to be a "wouldn't".

And yes, that was a constructive and clarifying post, and, thus, it was also a valuable post.

:D

MacLeod

audiobliss wrote:

*****************

Thats better.

glemay

MacLeod,

Then what would you suggest I do? I need an amp to run four speakers in my boat.

1) I can buy myself a new amp and leave the clarion on the sub
2) I can use the clarion for myself and get a new one for the sub
3) other

We I get better performance or something with a class D?

Thanks

MacLeod

I dont understand that question.

What Clarion?

If you buy yourself an amp, then who would need one for the sub?

One thing tho, its not that a Class D performs better than an A/B, its that theyre more effecient and be smaller and take up less juice for the same power. 400 watts from a A/B will sound just like 400 watts from a D.

glemay

MacLeod,

Oh, sorry. I will explain. We currently have a 2 channel Clarion amplifier on my dad's boat running a subwoofer. I am working on my boat and will need a amplifier to run 4 speakers. I am thinking about either buying myself an amplifier or taking my dad's Clarion and replacing his with a class D amplifier. I have two options, what would be the best choice?

Hope that clears things up a little.

Jerry

MacLeod

I would buy yourself a good 4 channel amp and leave the 2 channel on the sub. A class D aint gonna make any difference.