What kind of amp - PeachParts Mercedes-Benz Forum

MarkM · #1 12-27-2006, 08:25 PM

I am a real neophyte when it comes to car audio. I have a few very simple questions. I have a 1984 MBZ 3ooTDT (wagon) that I will be adding speakers to. Here is my current setup:

New head unit - Pioneer DEH-P480MP (Premier)..it puts out max of 50 W per each of four channels, and about 25W RMS per channel.

I have completely bypassed the fader on the center console and have run new wires to speakers.

Current front dash speakers are cheap coax. older Pioneer 3.5 ", which I plan on replacing with 4" MB Quart Reference component speakers. I may mount woofers and tweeters together (if there is room) , or I may mount as separates with tweeter elsewhere.

In the rear, in original locations, I have two Boston Acoustic 4" coax speakers (S45)...each speaker has an RMS rating of 35W, and a max of 70W. I am driving these with an old Sony 2/1 amp (XM-2351) which has an RMS output of 35 watts @ 4 ohms per channel, and a max of 70W per channel. This is a good match for the rear speakers, and I plan on leaving this setup as it functions as rear fill, and provides high freq. sound, esp. for listeners in the back seat.

I plan on adding two 6.5 inch MBQuart "add-a-woofer" mid bass speakers to the rear doors where the ash trays are...RCE 164's, with a rating of 60W RMS per speaker, and a max of 130W per speaker.

My Questions:

If I run the RCE 164's off of the Pioneer head unit, will they be grossly underpowered, or do you think an amp is necessary.

If an amp is needed, what amp do you recommend...i'm considering some type of used Pioneer or Alpine 2-channel amp...what RMS wattage is best...should I try to exactly match the RMS rating of the speakers.

What about getting a 4 channel amp and using it for both the RCE 164's in the rear doors, as well as the S45 Boston Acoustics in the rear. If I do this, I may use the little Sony amp to drive a small 8" woofer in a box in the rear. I really dont want to get into any high power stuff, or large dual woofer enclosures. A little 8" woofer in the back of the wagon would probably satisfy me. BUT, if I use a 4 channel amp for both the 6.5" RCE 164's and the 4" S45 Boston Acoustics, don't I run the risk of greatly over powering the S45 rears.

So the way I am leaning is to forget about a woofer, leave the S45 rears as is, put in new 4" MBQuarts in the dash and drive off the head unit, and get a small 2 channel amp to drive the 6.5 RCE 164's in the rear doors, or just drive these off of the head unit.

Any thoughts,

Your help is greately appreciated.

Thanks,
Mark

Hit Man X · #2 12-28-2006, 10:44 PM

HU power is trash, low, and limited range. Amp everything.

Never can have too much CLEAN power. Dirty, distorted power is what kills speakers. I have 150rms going to a pair of 40w RMS rated Polk DX6s in one vehicle... how can that be? The RMS rating is for full range, 20-20000Hz. Cross them and your power capacity rises vastly.

Zeus · #3 12-29-2006, 09:30 PM

Quote:

Originally Posted by Hit Man X

HU power is trash, low, and limited range. Amp everything.

Never can have too much CLEAN power. Dirty, distorted power is what kills speakers.

Completely agree. Those headunit ratings are ridiculous.

I'm running an Alpine head into the 4 stock original 4" speakers with a 10" Infinity sub in a box in the trunk. I have an Alpine V-power 4-channel amp set at HP which powers the stock speakers; and another Alpine V12 2-channel amp, bridged, set at LP powering the sub.

I've got plenty of bass and the stock speakers actually sound quite decent, with enough clean power behind them. Eventually, I'll add new speakers to replace the stock ones.

I wouldn't worry too much about the amp's ratings. Go for quality. My Alpine V12 is a great amp, well-built and although its advertised wattage rating is lower than say, a cheap Sony Xploder amp from BestBuy, you can bet it will perform better. It certainly pounds the sub, no problem. I've got plenty of headroom left if I need it.

I'm not sure about your mid-bass door speaker idea. I would go for a separate sub instead, with its own amp, set with a low-pass filter.

Same for your smaller speakers - separate amp, set at high pass.

Another thing that kills speakers fast is asking them to deliver frequencies they can't handle. Match your ratings and handling characteristics and things should sound just fine.

Good luck!

denim · #4 01-12-2007, 12:42 PM

For an outstanding 4 channel amplifier that ranks with Zapco but much lower in price, check out the Sundown Audio 100.4.

1985 300SD Sady · #5 01-12-2007, 01:35 PM

Quote:

Originally Posted by Zeus

Completely agree. Those headunit ratings are ridiculous.

I'm running an Alpine head into the 4 stock original 4" speakers with a 10" Infinity sub in a box in the trunk. I have an Alpine V-power 4-channel amp set at HP which powers the stock speakers; and another Alpine V12 2-channel amp, bridged, set at LP powering the sub.

I've got plenty of bass and the stock speakers actually sound quite decent, with enough clean power behind them. Eventually, I'll add new speakers to replace the stock ones.

I wouldn't worry too much about the amp's ratings. Go for quality. My Alpine V12 is a great amp, well-built and although its advertised wattage rating is lower than say, a cheap Sony Xploder amp from BestBuy, you can bet it will perform better. It certainly pounds the sub, no problem. I've got plenty of headroom left if I need it.

I'm not sure about your mid-bass door speaker idea. I would go for a separate sub instead, with its own amp, set with a low-pass filter.

Same for your smaller speakers - separate amp, set at high pass.

Another thing that kills speakers fast is asking them to deliver frequencies they can't handle. Match your ratings and handling characteristics and things should sound just fine.

Good luck!

I have a V-12 as well, and I absolutely love it!