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Discussion Starter · #1 ·
Hi guys I've put together quite a crappy system it seems. It's got a problem for sure.

Sub amp is this Polk PA D1000.1:


The single subwoofer is this Skar EVL 12:


For some reason, the amp needs to have the gain set at the highest and the 'bass boost' set at the highest to get any kind of significant performance from the sub.

And although the sub sounds great when I do max out these two settings on the amp, the sub gets way too hot and starts smelling very strongly. I'm quite sure I've reduced the lifespan of the subwoofer by playing it hard the other night while testing. Very strong glue and other such smells filled my trunk although no smoke was emitted.

For now my head unit is this Sansa clip jam:


I've run tons of amps off this source unit and never had a problem. It has always delivered a plenty juicy signal and I usually only have to turn up the gain on amps halfway or less.

And I've also tried using the factory HU to a PAC LOC with the same exact results. So, the problem doesn't seem to be the signal that's getting sent to the amp and sub.

I've done probably 4 systems myself in my lifetime and have never seen a problem like this. Amps usually only need to have the gain set at about half or even less.

Me and my friend got to talking today and surmised that maybe this D2 sub is wired out of phase with itself inside the enclosure. That would be crazy and would be coming from the factory because although I had to unload the enclosure to get it into the car and then reload it, I only disconnected the one wire from the enclosure terminals to the one set of posts on the sub. I didn't play around with the short wire inside the enclosure connecting the 2 sets of posts on the sub together. That was done at the factory.

I read 2 conflicting reports tonight on dual voicecoil subs wired out of phase. One says no movement and damage will occur. The other says you'll just lose 20% of output and the subwoofer will get hot. Well, my experience matches the 2nd report.

I'm loathe to unload the enclosure to check for this because I risk injury with such a heavy sub and the awkward angles of working inside a trunk. Thinking I'm just going to pay the excellent shop that did my power wire from front to back and big 3 to look at this for me.

Anyway, what do you guys think? Does this sound typical of what happens when a d2 sub is wired out of phase with itself or maybe is there some other problem?
 

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Hi guys I've put together quite a crappy system it seems. It's got a problem for sure.

Sub amp is this Polk PA D1000.1:


The single subwoofer is this Skar EVL 12:


For some reason, the amp needs to have the gain set at the highest and the 'bass boost' set at the highest to get any kind of significant performance from the sub.

And although the sub sounds great when I do max out these two settings on the amp, the sub gets way too hot and starts smelling very strongly. I'm quite sure I've reduced the lifespan of the subwoofer by playing it hard the other night while testing. Very strong glue and other such smells filled my trunk although no smoke was emitted.

For now my head unit is this Sansa clip jam:


I've run tons of amps off this source unit and never had a problem. It has always delivered a plenty juicy signal and I usually only have to turn up the gain on amps halfway or less.

And I've also tried using the factory HU to a PAC LOC with the same exact results. So, the problem doesn't seem to be the signal that's getting sent to the amp and sub.

I've done probably 4 systems myself in my lifetime and have never seen a problem like this. Amps usually only need to have the gain set at about half or even less.

Me and my friend got to talking today and surmised that maybe this D2 sub is wired out of phase with itself inside the enclosure. That would be crazy and would be coming from the factory because although I had to unload the enclosure to get it into the car and then reload it, I only disconnected the one wire from the enclosure terminals to the one set of posts on the sub. I didn't play around with the short wire inside the enclosure connecting the 2 sets of posts on the sub together. That was done at the factory.

I read 2 conflicting reports tonight on dual voicecoil subs wired out of phase. One says no movement and damage will occur. The other says you'll just lose 20% of output and the subwoofer will get hot. Well, my experience matches the 2nd report.

I'm loathe to unload the enclosure to check for this because I risk injury with such a heavy sub and the awkward angles of working inside a trunk. Thinking I'm just going to pay the excellent shop that did my power wire from front to back and big 3 to look at this for me.

Anyway, what do you guys think? Does this sound typical of what happens when a d2 sub is wired out of phase with itself or maybe is there some other problem?
According to Skar, the sub only weighs 10 1/2 pounds.
 

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It's 33lbs.
The sub motor is 166 ounces (10 pounds 6 ounces), maybe 33 pounds with the box. But you only need to remove the sub from the box to fix your wiring.
 

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It sounds like everything is wired properly, but you as an end user are expecting too much from a single 12. Turn the gain down and the bass boost off before you melt the sub.
 

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That is of course another distinct possibility. It all depends on OP's expectations, experience, subjective impressions and characterization, and on our interpretation and assumptions.

Given my experience with the output potential of the lowly Skar IX-8 (both sealed and vented), a vented EVL-12 should be loud as [email protected] But loud as [email protected] to me may be underwhelming or even somehow problematic to the OP.

I'm kinda on the fence at this point...
 

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That is of course another distinct possibility. It all depends on OP's expectations, experience, subjective impressions and characterization, and on our interpretation and assumptions.

Given my experience with the output potential of the lowly Skar IX-8 (both sealed and vented), a vented EVL-12 should be loud as [email protected] But loud as [email protected] to me may be underwhelming or even somehow problematic to the OP.

I'm kinda on the fence at this point...
my guess is a combination of some settings are wrong on the amp or HU, and he expects too much. By saying the sub gets hot and smells, that tells me its playing loud AF.
 

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Discussion Starter · #14 ·
HU is my mp3 player and bass is set to max. Like I said, I've never experienced having to max the source, amp gain, amp bass boost, and amp bass knob to get max excursion from a sub. Just for clarity, if I turn down all of these settings to about half, the sub barely plays and doesn't even move.

So the consensus is that if the sub it wired out of phase with itself it will just play poorly? The article by MTX on this issue about the sub not moving at all and just getting hot is probably erroneous?
 

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Discussion Starter · #15 ·
This account tells of the woofers not moving at all when wired out of phase.


I'm reluctant to be just switching them to see how it goes.
 

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HU is my mp3 player and bass is set to max. Like I said, I've never experienced having to max the source, amp gain, amp bass boost, and amp bass knob to get max excursion from a sub. Just for clarity, if I turn down all of these settings to about half, the sub barely plays and doesn't even move.

So the consensus is that if the sub it wired out of phase with itself it will just play poorly? The article by MTX on this issue about the sub not moving at all and just getting hot is probably erroneous?
Check the impedance at the terminal and tell us what it reads. I could be wrong, but i think its impossible to wire a single DVC sub out of phase and still get music out of it.
 
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Discussion Starter · #17 ·
Yes will do. No idea how to check impedance at the terminal but I got a multimeter and will research how. Thank you for the guidance.

I'm starting to think this lovely Polk amp with great reviews is faulty. I've never seen anything like this. I've hooked up this little matchbox size mp3 player to probably 7 or 8 amps in my "run car audio gear in the home, usually ppi art, hobby", and I've never had such a problem with gains like this. Just looked at my Soundstream Reference 500 that I recently connect this mp3 player to, and the gain is set at a hair over half.
 

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Yes will do. No idea how to check impedance at the terminal but I got a multimeter and will research how. Thank you for the guidance.

I'm starting to think this lovely Polk amp with great reviews is faulty. I've never seen anything like this. I've hooked up this little matchbox size mp3 player to probably 7 or 8 amps in my "run car audio gear in the home, usually ppi art, hobby", and I've never had such a problem with gains like this. Just looked at my Soundstream Reference 500 that I recently connect this mp3 player to, and the gain is set at a hair over half.
where is the LPF set on that amp. If fully counter clockwise then you are getting no sub signals to the sub. raise it to about 11 oclock.

Also is the remote bass controller plugged in? Sometimes amps wont run without that being plugged in.
 

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Check the impedance at the terminal and tell us what it reads. I could be wrong, but i think its impossible to wire a single DVC sub out of phase and still get music out of it.
I would expect the ohm reading of the combined voice coils to be the same regardless of phase, but maybe the there's a shorted coil? ...or?

I too would assume out of phase voice coils would cancel each other out. I read somewhere that they would be down 20dB, with no rationale given for that assertion. I'm tempted to experiment, but I don't want to hurt anything.
 

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Discussion Starter · #20 ·
where is the LPF set on that amp. If fully counter clockwise then you are getting no sub signals to the sub. raise it to about 11 oclock.



Also is the remote bass controller plugged in? Sometimes amps wont run without that being plugged in.
I previously tried maxing and minning the LPF on the amp. Made no difference in volume level but did effectively cut off higher bass frequencies when set one way. I currently have it set max clockwise if I recall correctly without looking at the amp in the vehicle as I'm here at my desk. This setting resulted in the highest frequencies passed through.


Yep, bass knob is plugged in and working fine.
 
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