4 Channel Amp Help

[dysfunction26 10+ year member]

I have a Sony XM-4S 4 channel amplifier. I have a Polk component set up front and Polk 6x9's in the rear. I want to add a single 10" sub. Currently the amp has the components hooked up to channels 1/2 and the 6x9's hooked up to channels 3/4. Is there any reason I would not be able to run the components and 6x9's on channels 1/2 and bridge 3/4 to power the 10" sub? The amp manual says it will put out 95 watts x 2 and 205 watts x 1 that way. Will that effect the sound quality I get up front, by having one 6.5, one tweeter and one 6x9 hooked to each channel (1 & 2)?

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[Buck 5,000+ posts]

get a nine.5

 

[Got_Bass89 10+ year member]

Yes will effect it alot... Will cut your power in half... Less power less sound. Better off just adding another small amp just for your sub.

 

[dysfunction26 10+ year member]

Yes will effect it alot... Will cut your power in half... Less power less sound. Better off just adding another small amp just for your sub.

How is it cutting the power in half? It states 50 watts per channel x 4, if you run 3 channels it says 95 watts x 2 and 205 watts x 1. That is all RMS according to the specifications. Channels 1 & 2 should have 95 watts RMS each, if you take in example the 200 watts RMS from using all 4 channels, then it's only 10 watts RMS less if I run 2 channels, in 3 channel mode (bridging channels 3 & 4). Is the math different for amplifiers, because I'm an accountant and the cutting my power in half doesn't add up to me (numerically speaking).

 

[jrwalte 10+ year member]

The amp probably won't even work. The ohm load would be too low due to placing 2 speakers (1 component and 1 6x9) on the same channel. And we won't even get into all the problems you could create if the 6 x 9 and component aren't at the same ohm. Bad idea to mix different speakers on the same channel ever.

 

[dysfunction26 10+ year member]

The amp probably won't even work. The ohm load would be too low due to placing 2 speakers (1 component and 1 6x9) on the same channel. And we won't even get into all the problems you could create if the 6 x 9 and component aren't at the same ohm. Bad idea to mix different speakers on the same channel ever.

They are both Polk Audio and both are 4 ohm speakers. Am I getting personal opinion, or fact? It seems I am getting half answers, you say it won't work, but what are the specifics? Why exactly won't it work, both speakers are the same make and same OHM and pretty much handle the same amount of watts.

 

[dysfunction26 10+ year member]

Bump

 

[jrwalte 10+ year member]

They are both Polk Audio and both are 4 ohm speakers. Am I getting personal opinion, or fact? It seems I am getting half answers, you say it won't work, but what are the specifics? Why exactly won't it work, both speakers are the same make and same OHM and pretty much handle the same amount of watts.

They're 4 ohm because you're connecting 1 speaker to 1 channel. Add other speakers to that same channel and you change the ohm resistance. When you wire in parallel, two 4 ohm speakers connected on 1 channel would give you a 2 ohm load. And if one speaker is 8 ohm and the other 4 ohm, you'd be giving the one at 4 ohm much more power than the 8 ohm, because electricity follows the path of least resistance.

Unless you know alot about ohms and electricity, it isn't wise to mess with mixing speakers on the same channel (subs are different, a little easier to understand because you don't have component systems).

 

[MikeATL 10+ year member]

I'd recommend a seperate amp for your sub as well. I would guess that that amp is stable at 2ohms and you'd technically be fine doing that but you'd lose the ability to fade front/rear. Losing control of my soundstage wouldn't be acceptable for me but may not be an issue for you. As long as your amp is 2ohm stable on the stereo channels and your sub will present a final 4ohm load I'd say give it a shot and see if you like it. I doubt that amp is stable at 2ohm on the bridged channel though so if your sub is d4 you don't really have a choice.

I'm guessing you'll be underpowered on the sub and will end up getting a dedicated amp.

 

[siacarman 10+ year member]

for a 200 watt output you can pick up a 200 watt for next to nothing...just post a wtb add...better to do that then take the risk of frying your amp..or making everything sound like azz..just my .02

 

[dysfunction26 10+ year member]

I'd recommend a seperate amp for your sub as well. I would guess that that amp is stable at 2ohms and you'd technically be fine doing that but you'd lose the ability to fade front/rear. Losing control of my soundstage wouldn't be acceptable for me but may not be an issue for you. As long as your amp is 2ohm stable on the stereo channels and your sub will present a final 4ohm load I'd say give it a shot and see if you like it. I doubt that amp is stable at 2ohm on the bridged channel though so if your sub is d4 you don't really have a choice.
I'm guessing you'll be underpowered on the sub and will end up getting a dedicated amp.

These are the specs of the amp:

Inputs and Outputs

• RCA Audio Input(s) --- Pin Jacks: 0.3 - 6V

• Line Level Input(s) --- High Level Connector

• Input(s) --- Level Adjustment - High Level Input: 1.2 - 12V

 

Speaker

• Speaker Terminal Type --- Output

 

Audio

• Impedance --- 2 - 8 Ohms Stereo; 4 - 8 Ohms (when used in bridged mode)

• Frequency Response --- 5 Hz - 100 Khz (+0/-3 db)

• Harmonic Distortion --- 0.005% or less (at 1 Khz, 4 Ohm, 10W)

• Low Boost --- 0 - 10dB (40Hz)

• Circuit System --- OTL (output transformerless circuit)

 

Power

• Output Power --- Four Speakers 95 W x 4 (at 4 Ohms); Three Speakers 95 W x 2 + 250 W x 1 (at 4 Ohms)

• Internal Power Supply --- Pulse Power Supply

• Power Requirements --- 12 V DC car battery (negative ground)

• Current Drain --- At rated output: 27 A (4 Ohm, 50W x 4) Remote Input 1 mA

• Rated Output --- Four Speakers: 50 W x 4 (20 Hz - 20 kHz, 0.04% THD at 4 Ohms); 60 W x 4 (20 Hz - 20 kHz, 0.1% THD at 2 Ohms)

 

General

• Power Supply --- 10.5 - 16 V

 

Weights and Measurements

• Dimensions (Approx.) --- 8 7/8 x 1 3/4 x 7 3/4" (223 x 43.5 x 196mm)

• Weight (Approx.) --- 4lbs 14oz (2.2Kg)

 

Colors

• Black and Chrome Silver

I have a small vehicle (Toyota Echo) and wanted to steer clear of another amp if possible. If the amp can handle it, I'd just prefer to use that alone. I don't want to put the load of two amps on such a small car, I'm pretty sure the alternator can't take it.

 

[dysfunction26 10+ year member]

These are the specs on the subwoofer:

Max Power: 800 Watts

RMS Power: 400 Watts

Frequency

Response: 30Hz-180Hz

Sensitivity: 88 dB

Magnet Size: 50 oz.

 

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It's not a high end sub, just a cheap 10" that will do the trick in a small vehicle like mine.

 

[benchambers80]

It will work but sony will probably fry @ 2 ohms.

 

[dysfunction26 10+ year member]

If I do buy a second amp, would I have to purchase another amp installation kit? Or can the amps be linked together? These are the connections available on the Sony amp:

 

[dysfunction26 10+ year member]

Also. do you think that would be too much for the alternator on a Toyota Echo to handle, powering both amps?