Speaker Install - Once and for all... Is the polarity reversed on Metra connectors?

[Ozz]

Greetings,
I replaced all four speakers in my MM with Kenwood 6889's this week and used the Metra 72-5600 splice wires so I wouldn't have to cut my factory harnesses. Since the factory wires and speakers to not have polarity shown, I assumed that the Metra connectors were correct (large spade to +, small spade to -). The sound improvement was not as drastic as I anticipated so I started investigating. I found this thread regarding the possible polarity reversal of the Matra harnesses:

http://www.mercurymarauder.net/forums/showthread.php?t=1872

Bottom line is, if the connectors are reversed, I will go in and fix them. Can anyone tell me beyond a shadow of a doubt if I need to cut, reverse and resolder the large/small spade connectors on the Metra's?????

Thanks!

[czbill]

Greetings,
I replaced all four speakers in my MM with Kenwood 6889's this week and used the Metra 72-5600 splice wires so I wouldn't have to cut my factory harnesses. Since the factory wires and speakers to not have polarity shown, I assumed that the Metra connectors were correct (large spade to +, small spade to -). The sound improvement was not as drastic as I anticipated so I started investigating. I found this thread regarding the possible polarity reversal of the Matra harnesses:

http://www.mercurymarauder.net/forums/showthread.php?t=1872

Bottom line is, if the connectors are reversed, I will go in and fix them. Can anyone tell me beyond a shadow of a doubt if I need to cut, reverse and resolder the large/small spade connectors on the Metra's?????

Thanks!

According to one company, Electra-Tech I think, you can watch the speaker when the radio power is turned on. The speaker should pop upward, not inward. The movement is slight, I needed lots of light to see it. All speakers should move the same way when powered up.

[RF Overlord]

Can anyone tell me beyond a shadow of a doubt if I need to cut, reverse and resolder the large/small spade connectors on the Metra's?????Beyond a shadow of a doubt? No...

The subject of absolute phase and phase inversion is one that occupies MANY audiophile discussions for days on end...

Some say phase inversion (in the speaker world it's called polarity reversal) cannot be heard, especially by the ordinary listener. Others claim to be able to hear it.

The general consensus is that as long as all the speakers in a listening area are phased the SAME, it doesn't matter whether they are all "normal" or all "polarity-reversed".

You say "The sound improvement was not as drastic as I anticipated...". How did you know how much of an improvement to expect? Have you heard the EXACT same setup in someone else's Marauder? If not, then what did you judge the improvement level on? Sometimes the best improvements are subtle. Case in point: my car...I replaced the speakers with Infinitys and found they didn't change anything "drastically", but they made the bass smoother, and the highs clearer...I guess you could say the overall sound was "cleaner" and easier on the ears. And I believe the adaptors Crutchfield sent did the same polarity reversal as yours...I didn't bother with all the cutting and soldering...I don't believe it matters at all.

[Ozz]

Thanks for the replies.

What about trying to be in phase with the subwoofer? I did not modify its connection. I went and confirmed that, based on the wiring diagram provided in the other thread, that my deck and door speaker polarity did change with the addition of the Metra splice wires. Will this be an issue?

As far as what I expected - I actually had to turn up the treble to get enough out of the new speakers. It seemed softer than the stock speakers. I did not expect to have to do this. I was able to lower the bass slightly.

Bottom line is that I will take the time to do whatever is right - if I can figure it out. An Audiophile friend of mine said that I should not drive the speakers with reversed polarity since they were not really designed to do that. The woofers would tend to be pulled out instead of being pushed it. He also said the phase difference would cause the high frequency sounds to reach the ear much faster than the low end sound. This causes the music to be overly 'bright'. This is not something I noticed but the music did seem to lack 'depth'.

[RF Overlord]

What about trying to be in phase with the subwoofer? Will this be an issue?That's a good point...if the other speakers are high-pass filtered in the head unit, then the answer is no. Otherwise, it would be a good idea to restore the other speakers to the original polarity...although, it may be easier to flip the polarity on the sub, rather than taking the door panels off, cutting & soldering 4 sets of wires, etc...

[Ozz]

RFO,

Please check out my previous reply - I edited it and added more info... Thanks.

[RoyLPita]

I spent the $$$ and went through Crutchfield for their adaptors. I've had no problems with them.

[RF Overlord]

An Audiophile friend of mine said that I should not drive the speakers with reversed polarity since they were not really designed to do that. He also said the phase difference would cause the high frequency sounds to reach the ear much faster than the low end sound. This causes the music to be overly 'bright'.I'm sorry, and I mean no disrespect, but your friend is wrong...lemme see if I can 'splain:

You know what a sine wave is, right? For those who don't, it's a curve that starts at zero, goes up to a positive peak then back down again, through zero, to a negative peak, then back to zero again. How rapidly this happens determines the frequency we hear. If it does this 1000 times per second, it's called a 1 kilohertz signal.

Now imagine a sine wave that starts at zero, goes DOWN to a negative peak, then back UP again, through zero, to a positive peak, then back to zero again. This is the EXACT same 1 kilohertz signal, only 180° out of phase with the first example (call it phase inversion or polarity reversal...it's the same thing in this case). There is NO audible difference in these two signals.

As for your friend's comment that speakers are "not really designed to do that", think about it for a moment. In both of the examples I gave above, the speaker cone is at rest at the zero point, pushed out for a positive peak and pulled in for a negative peak, both equally. The speaker neither knows nor cares whether it pushes out first or pulls in first, it MUST respond equally to both positive and negative peaks, or the sine wave becomes non-linear and massive distortion would occur.

I don't understand his comment about high frequencies reaching the ear faster...sound travels at ~1127 ft/sec, regardless of frequency or absolute phase.

Remember, I am talking about multiple speakers occupying the same acoustic space all being in phase with each other, inverted phase not withstanding. If you have one (or more) speaker(s) OUT of phase with the rest, THEN you can have major frequency-specific cancellation/augmentation issues. Maybe that's what your friend was referring to.

[Agent M79]

I am not an audio technician. I used the Metras in whatever way they were supposed to be used and did not have any problems that I was able to tell.

My improvement was far better than marginal.

[valleyman]

Bottom line is, if the connectors are reversed, I will go in and fix them. Can anyone tell me beyond a shadow of a doubt if I need to cut, reverse and resolder the large/small spade connectors on the Metra's?????

Thanks![/QUOTE]

I can. Beyond a shadow of a doubt the polarity is reversed from OEM. Whether it makes an audible difference or not to you, only you can tell.

[Ozz]

RFO,

I will ask my friend to clarify what my he meant. I paraphrased what he said and probably got it wrong. He is a very intelligent individual and has been obsessed with this stuff for awhile so I know he probably was thinking of the speakers being out of phase with eachother (not the subwoofer)...

Thanks.

I think what I am going to do is take the Metra connectors, cut a patch of insulation off of them in the middle of their length and add another set of spade connectors so that I can try them the other way to see if I like it better.

[RF Overlord]

I think what I am going to do is...add another set of spade connectors so that I can try them the other way to see if I like it better.That sounds like an eminently satisfactory solution... :up: :D

[Ozz]

Last night I spliced additional spade connectors to the Metra's so I could reverse the polarity. I must say that I can tell a difference. With reversed polarity, I had to increase the treble (1 notch from maximum) and decrease the bass for it to sound right but after correcting it, I moved them back to where I had them before the swap. I noticed more midrange as well after the correction. Another thing I found with the polarity reversed was that I couldn't seem to get the fade and balance to an acceptable level. With the mods I did last night, all is well again.

I asked my audiophile friend to clarify his earlier statement. He was assuming I was using component speakers and that they were out of phase (woofer to mid to tweeter)....
Here is what he said:
"ok if these are not component speakers most of what I was saying is hardly applicable.
For 3 ways with SINGLE inputs, yes all would be out of phase in the same manner. this is the very reason why you had to crank the treble way up and the bass down a little for things to sound right. high freqeuncies are very directional...think beeming sounds...your dome tweeter was trying to behave like an inverted dome firing the wrong way. no detail or sparkle and a very soft and uninvolving sound. bass would be lacking a little in impact and pitch definition but have just as much perceived output."

With the subwoofer out of phase the bass was slightly muddy but just as loud. It is more crisp now.

Call me crazy but the polarity made a difference to me! Not to say the overall sound wasn't better with the new speakers, just that it was even better with correct polarity. :)

[rookie1]

As for your friend's comment that speakers are "not really designed to do that", think about it for a moment. In both of the examples I gave above, the speaker cone is at rest at the zero point, pushed out for a positive peak and pulled in for a negative peak, both equally. The speaker neither knows nor cares whether it pushes out first or pulls in first, it MUST respond equally to both positive and negative peaks, or the sine wave becomes non-linear and massive distortion would occur.

I don't understand his comment about high frequencies reaching the ear faster...sound travels at ~1127 ft/sec, regardless of frequency or absolute phase.

Remember, I am talking about multiple speakers occupying the same acoustic space all being in phase with each other, inverted phase not withstanding. If you have one (or more) speaker(s) OUT of phase with the rest, THEN you can have major frequency-specific cancellation/augmentation issues. Maybe that's what your friend was referring to.

absolutely true. Phase is irrelevant if all speakers are the same. The improvement you noticed after reversing them was a result of putting them back in phase with the subwoofer correcting some mid bass cancellation thus making the bass less muddy and clearer.
Not to nit pick , but, I 'm not certain that wiring the high frequency components out of phase with the woofers in a separate component set up would make any difference if a high quality crossover were used. Crossovers are designed to roll off frequencies at the crossover point, if these frequencies were rolled off steeply at say 12 or more db per octave I don't know if the cancellation would be audible.

[Ozz]

Perhaps cleaning up the mid-bass mud made it easier to hear the high frequencies or something...

[the_pack_rat]

Ok ...

We've established the metras have reversed polarity.

We've also established that this reversed polarity should NOT matter if & only if ..... ALL speakers AND the subwoofer of the system are in fact connected in the SAME manner.

With that said ...

Ozz's perception that the output indeed in fact sounded better to him after after having BOTH the speakers AND subwoofer back in "phase" again ...

Was NOT an imaginary thing ... but in fact a LEGIT improvement ?.

Long story short ...

Should I dive back into my car & either :

Reverse all (4) of the metra speaker connectors ?.

OR ...

Just reverse the connector for the subwoofer ?.

My system is ALL stock cept' for the Infinity Reference speakers.

I'm satisfied with the present sound the way it is ...

But if re-versing some connections would improve the sound even further ... I'm all for it.