need help..quick

[mrray13 30]

today iinstalled 2 15" idq's in individual sealed compartment..maybe 1.75ft^3 a piece, being pushed off a memphis pr series amp(the big 2 channel one) and here's the deal...after a few bass hits..it quits playin....one sub sucks in and the other pushes out. u turn the h/u for a few seconds, it'll start playing again and then uit again.

here is what i checked..

1) the amp never goes into protect mode and doesn't shut off when the subs quit playin...also the amp was benched about a month ago because of the same problem..different car...tested ok

2) all connections are tight..had to fix a few on the box terminals

3) changed from mono bridged to stereo to play with the impedence a little ( the subs are ran in series on the vc's) still did the same thing..even reverse polarity to make sure the subs were in phase...they were

4) ran it for a minute with only one sub(the one that pushes out at cut off) and it didn't do it, but the connection was loose on the other box terminal..which i fixed

5) i think it's the sub that sucked in at cut off, because of what happened in #4..but what is causing it to shut both subs off? should i recommend new subs..or just get them checked out and fixed? what causes what i'm describing?

any help will be appreciated..

wheeeeeeeeeeeeeeeeeeeeeeeeeee

[sandt38 448]

One sucking out and one sucking in is likely just that they are wired out of phase. Use a 9 volt battery to pop the subs and check polarity.

It sounds like for some reason the amp is holding a DC signal rather than AC. If it is doing this with both subs hooked up, but not with 1 sub hooked up, my assumption is a thermal protect. Sounds like a bad load on the amp.

That still doesn't make alot of sense that it would hold a DC signal for protect... that is very hard on the subs as they need movement for cooling. I'd check with a DVOM (DMM, whatever you want to call it) to ensure this is a DC signal. Run it with AC voltage selected, and keep an eye on the voltage, when it locks the subs down, see if it is emmiting an AC signal at all (I think not) then switch to DC on the meter. If it shows a DC voltage, shut that bad boy down fast, there is some serious heat building in them coils. If not, it is going into protect. Disconnect the subs from the amp and see what happens to them.

Got a pic of the wireing, and some amp info? What is the coil config on the subs? Is it run series or paralel (judging by what you explain I bet series ), and what is the final desired load?

Edited February 23, 2004 by sandt38

[mrray13 30]

it's gotta be the amp..i tried just one sub today..and it still quit. the subs weren't in phase....the "professional" installers who originally wired the box, wired one backward at the quick connect...but even after that was changed..all it took is one good whack on the box to shut it off....i don't get it...

anyway..tomorrow the amp is going to the local memphis dealer to get benched.and while there they are going to check the vc's to make sure one of them isn't shorted out....

they are dvc 4...and the impedence needed is mono 4ohm..stereo 2 ohm

wheeeeeeeeeeeeeeeeeeeeee

[sandt38 448]

What did they determine? How are the subs wired? I hope it was series/paralell or they are overloading the amp.

[mrray13 30]

i won't know until this weekend...and i'll post what happened

wheeeeeeeeeeeeeeeeee