80w rms x 6

[SamV]

Hi guys,

I'm looking for an amp that can do 80w rms @4ohm x6 channels that is as efficient as possible that runs off 12volts.

Any ideas?

It's to go on my new bike sound system system, this is the old one



The new one will be similiar in size but at least 3db more efficient output wise, and a fair bit more efficient power wise due to upgraded components.

Any recommendations for amps? At the moment it's using a 4 channel JBL GTO75.4 car amp at 2ohm.

[AndrewT]

buy high efficiency speakers.

[Corax]

Terrific looking bike sound system - good job

Are you interested in building your own amps or do you want to buy what ever is on the market from known manufacturers (like JBL, JVC, Kenwood, Magnat, Pioneer, ...)?

In case you wanna go DIY my recommendations are the followings:

Either you decide to make your own class-D amps (look for such threads here) and the necessary SMPS (can be also found here) or you go for instance, if class-D would be to complicated for you, for class-H, in particular for TDA1562Q (from Philips => http://www.nxp.com/.

For the latter case you also find at least a PCB to buy at http://www.elektor.de/jahrgang/2000/...fe.59985.lynkx

If you've a colleague or friend who collects the magazine ELEKTOR (it's for sure published in NL and D but I'm not so sure about UK), it's in issue 350 from February 2000.

This chip-amp would be the closest to your power requirements with very few additional components and still some worth mentioning efficiency.
Talking about efficiency - considering the limited power resources you're going to "carry" with you (the batteries/accumulators), class-D amps cannot be outdo by other classes if we're talking about efficiency.

Good luck

[Bone]

The most you'll get out of 12 v in bridge mode into 4 ohms is about 18 watts!! About double into 4 ohms. To get more you'll need an inverter.

[SamV]

The current subs and speakers are 94db/1w/1m sensitivity.

If the last post is correct then what about all the car amps you see? How can my JBL amp output 4x105w rms or 2x 284w rms?

[leadbelly]

Originally posted by SamV
If the last post is correct then what about all the car amps you see? How can my JBL amp output 4x105w rms or 2x 284w rms?

The last post is correct. Your JBL amp has what is effectively an inverter or upconverter inside of it.

[SamV]

Ah I knew that though. Stop trying to confuse me lol

[footstony]

Hi SamV,

Great system! Corax is on the ball and his suggestions are good. Class D are the most efficient.
I am currently evaluating a TDA1562Q amp kit (class H from jaycar in Australia) for use with a portable system. This chip uses extra capacitors to boost the rail voltage during peaks giving 36w rms into 4 ohms and 70wrms "music power" depending on battery voltage.

Most car amps draw a lot of current are rated at 2ohms and the RMS figures are BS!

Go for the high efficiency speakers. 94db/1w/1m is good but 100db/1w/1m would give you 4 times the acoustic output for the same amp power and battery life.

see here:
http://www.billfitzmaurice.com/

put some wheels on this!
http://www.billfitzmaurice.com/THT.html

maybe the last idea was a bit silly...

Regards Philip

[chris7916]

Why not "AMP9 basic" from 41Hz ?

Christian

[SamV]

Trouble with 100db/1w/1m drivers is that they are not usually equipped with handle moisture and are usually expensive and heavy. Though yes 100db would be awesome.

I have had a look at the AMP9, but I'm not an electrical person, and my solder skills are a bit beginner, ideally I just I was hoping to find links to a 2x80w rms @4ohm amp boards which I could get three of and then ask a friend/someone to build them up to plans and then bung in a suitable power supply.