SA-8 coil gets hot fast

[ShagggDiesel 25]

I have a buddy that I built a box for and installed two SA-8's. He bought both of them used, one from Darren Francis, the other from a local guy. Anyway, with the subs wired in series/paralell for a 4 ohm load, one of the subs gets extremely hot after only about 3-5 minutes of play. If the sub hasn't been played and is cool, there is no scratching when pushed in, but when it's been played and gets hot, it has a little scratching noise when pushed in. Anyone know why this would be happening to only 1 sub? The other sub stays completely cool and plays fine. It is possible that one of the coils could be blown on the bad sub? I did a quick test with a DMM on the subs wired together and got a reading of 5.5-6 ohms. Anyone have any ideas? I haven't been able to go back to his house to test each coil independently yet.

The subs are being amped by an Alpine MRD-1000. No bass boost on the amp or HU.

[jonbearsmt 919]

sounds to me like the sub is wired into a direct short... remove the sub from the box and check the wiring.....

for some reason this is a commen user mistake on the SA series....

[ShagggDiesel 25]

sounds to me like the sub is wired into a direct short... remove the sub from the box and check the wiring.....

for some reason this is a commen user mistake on the SA series....

Could you explain how a direct short works with a speaker? The sub still plays fine and keeps up with the good sub. Wouldn't a short cause some odd effects to the performance of the speaker even though it's only 1 coil?

[Dictator 39]

whats a direct short?

[jonbearsmt 919]

i had a friend come to me with the same issue on a SA 12 that i sold him....

in his mind he thought that series would be like wiring up 2 12 volt batteries into series..

http://www.google.com/imgres?um=1&hl=en&client=firefox-a&rls=org.mozilla:en-US:official&biw=1280&bih=885&tbm=isch&tbnid=s-KkxrvyWmH3tM:&imgrefurl=http://mymilescity.com/how-to-solar-power/series_wiring_batteries.html&docid=qxLyRtDr1e5dUM&imgurl=http://mymilescity.com/images/series-battery-wiring.jpg&w=294&h=271&ei=rEdnT7boGqGGsgLstJi3Dw&zoom=1&iact=hc&vpx=364&vpy=332&dur=3846&hovh=216&hovw=234&tx=120&ty=89&sig=105210265450493815808&page=1&tbnh=159&tbnw=172&start=0&ndsp=20&ved=1t:429,r:6,s:0

but thats incorrect. that will directly short it.

[lithium 358]

are you sure they are both the same coil configuration?

[ShagggDiesel 25]

No, I'm not 100% positive. I did check the wiring 3 times before putting them in, but there could still be error. This is how I SHOULD have them wired:

Each sub has a wire from + on one coil to - on the other, then the two remaining + and - running in paralell to the other sub.. + to + and - to - on the free terminals on the other sub. I guess the only solution is to take them out and check again.

[jonbearsmt 919]

pics please.

[mathewdylang 2]

have you checked your ohms with both subs hooked up? its possible to have a d2 and d4. which means one would see a lot more power than the other.