A little help with speaker wiring

So I got an older S10 the other day. It has 4 x 10 speakers in the back that sound terrible. I already changed out the GM stereo for a Pioneer that I had in my car but the speakers in the back seem to muffle the sound and are not putting out the same volume as the ones that I had in the car. The 4 x 10's are pretty hard to find and I just happen to have four 4x4 speakers that I had purchased for my home theater and didn't like there. I am thinking that I can make a template and use them in the 4x10 spots. Thing is that they are 4 ohm speakers. I think that I can wire them in parallel and get 8 ohms but I am not sure what the end result would be. Should they be the same loudness as a single 4 or 8 ohm ? Should I just order a 4x10 even if the quality is not so good? I will replace the door speakers later but for now they are OK, not great but OK.

Sounds like you need an amp to push the 4x10" speakers to me

I wouldnt mess with the rear speakers, just unhook them. if they are louder or even as loud as the front speakers it will take away from your sound quality. Get a good set of fronts and call it a day

First, to take a pair of 4 ohm speakers and wire them to produce 8 ohms, you wire them in series. If you wired them in parallel, they'd produce 2 ohms of load on the amp.

Second, most car audio systems assume 4 ohm loads, and if your unit has front/rear faders it very likely has 4 amplifiers, meaning that you ought to present 4 ohm loads, not 8. You would have to check the unit's rating and specs to be sure.

Car's typically assume 4 ohms because at 12 volts (actually about 13 when the car is running), 4 ohm loads provide for twice the power potential of the 8 ohm loads.

However, there is almost zero relationship between the impedence of the speaker and the loudness of the sound you hear, when comparing models. Certainly comparing a single speaker, or two of exactly the same design, in a 4 or 8 ohm comparison, you'd hear some difference. The primary factor determining perceived volume is the efficiency of the speaker. Some designs are 10 to 20 times more efficient than others, often intentionally (though it's usually not the primary target, it's an accepted side effect of choosing better control over the speaker's accuracy).

Some car audio equipment is even designed to support 2 ohm loads.

Check...that might be your best choice if your device does that.

Have you tried parts-express.com?

ATMINSIDE said:

Sounds like you need an amp to push the 4x10" speakers to me

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Oh no, I do have an amp but the Pioneer was plenty loud enough in my Saturn that also had four speakers and there is a noticeable volume difference at the same settings. I do happen to have a Clarion amp but I think that it would be overkill in the cab of a pickup even though it is an extended cab.

dejo said:

I wouldnt mess with the rear speakers, just unhook them. if they are louder or even as loud as the front speakers it will take away from your sound quality. Get a good set of fronts and call it a day

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Well, I like that I can move the sound to exactly where my head is with four speakers.

jasonlylevene said:

First, to take a pair of 4 ohm speakers and wire them to produce 8 ohms, you wire them in series. If you wired them in parallel, they'd produce 2 ohms of load on the amp.

Second, most car audio systems assume 4 ohm loads, and if your unit has front/rear faders it very likely has 4 amplifiers, meaning that you ought to present 4 ohm loads, not 8. You would have to check the unit's rating and specs to be sure.

Car's typically assume 4 ohms because at 12 volts (actually about 13 when the car is running), 4 ohm loads provide for twice the power potential of the 8 ohm loads.

However, there is almost zero relationship between the impedence of the speaker and the loudness of the sound you hear, when comparing models. Certainly comparing a single speaker, or two of exactly the same design, in a 4 or 8 ohm comparison, you'd hear some difference. The primary factor determining perceived volume is the efficiency of the speaker. Some designs are 10 to 20 times more efficient than others, often intentionally (though it's usually not the primary target, it's an accepted side effect of choosing better control over the speaker's accuracy).

Some car audio equipment is even designed to support 2 ohm loads.

Check...that might be your best choice if your device does that.

Have you tried parts-express.com?

Click to expand...

Thank you, I guess I mis-remembered the difference between parallel and series wiring in speakers. It actually says that it supports both four and eight ohms in the manual and I do get that the speaker quality will be more determinant to the perceived quality and volume of the speakers, I just don't know if changing it from four to eight ohms will send less voltage and hence less volume. It also has a sound from the speakers that sounds like tape hiss, so either way they gotta go. I'll try parts-express.com now.

When comparing 8 ohms to 4 ohms, the voltage would remain the same, differing only by some small amount associated with drawing more power from the amp, if any. Instead, what happens is more current is drawn, which is effectively the same thing for your interests. A 4 ohm wiring would draw twice the current from the amp at the same voltage, and thus twice the wattage.

You'll usually see power amp ratings indicate power in watts at a particular load, and the 4 ohm rating is usually twice that as the 8 ohm rating. However, amps with limited current potential could rate the 4 ohm output at something less than twice the power, indicating it's not all that capable of providing full current at 4 ohms.


If the hiss you're describing is constant, even if the source material is silent, that would have to be coming from the electronics, not the speaker. On the other hand, if that sound is associated only with the speaker's attempt to produce sound, it's rattling of the physical structure. It could be that part of the speaker isn't functioning, and as a result you're "overdriving" the other parts, probaby the high frequency portion (if it's coaxial), which accentuates the hiss beyond "normal" perception.

At parts-express.com, they have 3 models of 4 x 10 listed. The Pyle is $33, but don't expect sub-woofer class bass from it. While they state power handling, they don't state efficiency or XMax (the one way distance the cone can move, indicating it's bass capability).

The Kennwood and Pioneer indicate they're 91db/watt/meter, and that's fair. The Pyle might actually be higher, but they don't state. This measure indicates how loud the speaker would be for a given watt of input power (at one meter distance).

At 4 x 10, I wouldn't expect powerful bass from anything anyway, so I don't know there's any reason to spend the $72 or $99 on the other two, but I'm not a particular fan of Pyle myself. Car audio is full of junk products, though, and Pyle is better than most. If you're using a subwoofer, it matters not. If your front speakers have the primary bass role, it matters less. Otherwise, I expect the Pyle is weaker on bass than the other two.

With all that said, I think I will just try it both ways and see if a single 4x at 4 ohms is as good as two wired in series at 8 ohms. I expect that even a single 4x speaker would be better than the 4x10 OEM POS. I got closer and it seems that the hiss only comes from one of the rear speakers, probable the voice coil is blown. I don't expect much bass from them but as I listen to older rock, I don't want any more then what was recorded in fact the highs are more important to me. Amazon has all of those same speakers and others for much less, they are around 60.00 a pair there. I am trying not to buy the rears so I can instead replace the fronts with what little money I have to spend. I will let you know how it goes.

Oh well, the 4 inch speakers would not fit single or together. I ended up ordering some from Amazon for 44.00 with rubber cones and aluminum tweeters. I found that the old GM one that I took out was 10 ohms and the cone had completely separated from the metal enclosure, no wonder it takes so much more volume for the same level. I am going to get a couple of Polk speakers today for the front doors and am expecting that they have probably deteriorated as much as the rear's. I appreciate the help and am expecting much better sound soon.