Just finished an install today on a friends car (1994 Toyota Corolla) It consists of the following:

Alpine CDA 9884

2 10" Fi SSD (brand new, no options) in a 1.35 cubic foot sealed enclosure

BIG 3 (4 AWG)

Stock batt up front, Motomaster Elimintaor in the rear

4 AWG wiring throughout

Memphis 16-MC1500D @ 2 ohms

For some reason, after no more than 10 minutes of test tones (from 25hz to 40hz) at around 75% volume the amp goes in and out of protect mode. All we were trying to do was loosen the woofers up a bit. Car was started, and gains weren't even at full potential.

Fuse holder w/ voltage display states that the voltage was around the 11.8V range before it went into protect (cars heater was on, voltage taken at rear batt)

We then went out fro a drive, and was listening to a variety of music. To my ears, this system doesnt sound anywhere near what it should sound like. For a 1500rms amp, it seems as though its no more than 600rms to the ear. Now I do realize that the woofers are brand new and aren't fully broken in, as well as the enclosure being a prefab sealed one (for the time being)

Can anyone point me in the right direction as to why the amp is going in and outta protect mode?

Also, why is it not sounding near its full potential?

sealed box is probably why. You are probably more used to listening to ported designs.

Play some tones or music above or around the 50hz range, i'm sure that area is decently loud in that box.

Get a dmm and measure ohm load at amp's terminals with the stereo completely off.

You should be reading no lower than ~1.3 ohms (after accuracy compensation)

If it's reading 0.6-0.8 or 2.8-3.2, it's wired incorrectly.

sealed box is probably why. You are probably more used to listening to ported designs.

Play some tones or music above or around the 50hz range, i'm sure that area is decently loud in that box.

Get a dmm and measure ohm load at amp's terminals with the stereo completely off.

You should be reading no lower than ~1.3 ohms (after accuracy compensation)

If it's reading 0.6-0.8 or 2.8-3.2, it's wired incorrectly.

I know for a fact that the woofers are wired correctly. Its something I always triple check. You are right about being used to ported enclosure, but at the same time, songs with higher freq notes just dont sound as loud as they should.

maybe you don't have enough power?

I got a buddy on here runnin 2 10s ported off of 2000w and those subs want more power.. just a smaller box.

We can't add more power to his current box because they move too much right now.

It sounds decent but i know they can get louder.

He did a 140.2 on music with the car off with that setup off a 35A fuse.

I'm pretty sure he can surpass a 142.5 with the car on with test tones but never really tested it since he doesn't compete in that method.

Gonna try and get him a 145 with the car off before the competing season is over in the trunk with the same setup.

maybe you don't have enough power?

I got a buddy on here runnin 2 10s ported off of 2000w and those subs want more power.. just a smaller box.

We can't add more power to his current box because they move too much right now.

It sounds decent but i know they can get louder.

He did a 140.2 on music with the car off with that setup off a 35A fuse.

I'm pretty sure he can surpass a 142.5 with the car on with test tones but never really tested it since he doesn't compete in that method.

Gonna try and get him a 145 with the car off before the competing season is over in the trunk with the same setup.

The amp is rated for 1500 rms @ 2 ohms. The SSD's are stock, with no options. On the other forum i'm part of (canadiancaraudio.com) many are saying that the older memphis amps are very tempermental. I'd like some American point of views lol

well, i'm not keen to memphis equipment but just on the protect mode itself, when you play a test tone, does the sound of the sub change right before it goes into protect?

You will need to be listening to the front fo the sub to be able to tell.

IF the sound output from the sub changes and sounds odd right before going into protect, you may have a signal issue causing the amp to go into protect.

I recently diagnosed a vehicle with that issue locally who is running a sundown 3000d. His preouts on his head unit needed to be grounded due to some defect in the headunit.

well, i'm not keen to memphis equipment but just on the protect mode itself, when you play a test tone, does the sound of the sub change right before it goes into protect?

You will need to be listening to the front fo the sub to be able to tell.

IF the sound output from the sub changes and sounds odd right before going into protect, you may have a signal issue causing the amp to go into protect.

I recently diagnosed a vehicle with that issue locally who is running a sundown 3000d. His preouts on his head unit needed to be grounded due to some defect in the headunit.

No awkward sounds. Just shuts off, and comes back on, basically going in and out of protect mode until you back off the volume. No sudden popping or anything like that.

thermal protection? is the amp hot?

Measure voltage at the power\ground terminals instead of the rear battery.

If neither lead to the answer.. i would check that ohm load again with the stereo off.

Nothing else would make sense if it's not low voltage, heat or low ohm load... These are the three main things that causes protection faults at high volumes.

thermal protection? is the amp hot?

Measure voltage at the power\ground terminals instead of the rear battery.

If neither lead to the answer.. i would check that ohm load again with the stereo off.

Nothing else would make sense if it's not low voltage, heat or low ohm load... These are the three main things that causes protection faults at high volumes.

Heat seems to be a large issue. 5 minutes into playing and its getting very warm to the touch. Amp is mounted on the back of the enclosure with rubber spacers to reduce vibration.

have you opened the amp up yet? And are the air holes on the amp free of any covered obstructions?

have you opened the amp up yet? And are the air holes on the amp free of any covered obstructions?

Have not checked out the amp guts as of yet. There are no air holes on the amp, other than where the fuses are located which is on the bottom of the amp, recessed behind the cover plate

So they have dual 2 ohm coils and are wired in series/parallel? Check each coil with a DMM, just to make sure that maybe one coil isn't defected or something and reading too low.

So they have dual 2 ohm coils and are wired in series/parallel? Check each coil with a DMM, just to make sure that maybe one coil isn't defected or something and reading too low.

Both woofers are dual 2 ohm. One is a recone, and one is brand new from Fi. When wired for a 2 ohm load, each woofer is @ 4 ohms

For some reason, after no more than 10 minutes of test tones (from 25hz to 40hz) at around 75% volume the amp goes in and out of protect mode. All we were trying to do was loosen the woofers up a bit. Car was started, and gains weren't even at full potential.

Fuse holder w/ voltage display states that the voltage was around the 11.8V range before it went into protect (cars heater was on, voltage taken at rear batt)

What do you mean not at full potential? How did you set the gains?

Maybe the amp doesn't likes 11.8V or lower, and draws more current that's (probably) why it heats up and maybe clips and shuts itself off.

For some reason, after no more than 10 minutes of test tones (from 25hz to 40hz) at around 75% volume the amp goes in and out of protect mode. All we were trying to do was loosen the woofers up a bit. Car was started, and gains weren't even at full potential.

Fuse holder w/ voltage display states that the voltage was around the 11.8V range before it went into protect (cars heater was on, voltage taken at rear batt)

What do you mean not at full potential? How did you set the gains?

Maybe the amp doesn't likes 11.8V or lower, and draws more current that's (probably) why it heats up and maybe clips and shuts itself off.

Gains were set with a multimeter, and so once we saw what full potential was (around the 3/4 gain area) we back it down to around 1/2 gain (because we want to break in the woofers slowly in these cold months) That 11.8V was the lowest it dropped at a 45hz test tone, which jumped right back up to 12V and up to 12.2V with the car's heater off

im with kirill007 on this......if voltage isn't high enough, wouldnt the amp go into protect?

For some reason, after no more than 10 minutes of test tones (from 25hz to 40hz) at around 75% volume the amp goes in and out of protect mode. All we were trying to do was loosen the woofers up a bit. Car was started, and gains weren't even at full potential.

Fuse holder w/ voltage display states that the voltage was around the 11.8V range before it went into protect (cars heater was on, voltage taken at rear batt)

What do you mean not at full potential? How did you set the gains?

Maybe the amp doesn't likes 11.8V or lower, and draws more current that's (probably) why it heats up and maybe clips and shuts itself off.

Gains were set with a multimeter, and so once we saw what full potential was (around the 3/4 gain area) we back it down to around 1/2 gain (because we want to break in the woofers slowly in these cold months) That 11.8V was the lowest it dropped at a 45hz test tone, which jumped right back up to 12V and up to 12.2V with the car's heater off

Setting gains with a multimeter is a bad idea...

You are probably over driving the amp with the headunit, a combination of the low voltage issues...

If it is getting hot you may very well have it wired wrong..

For some reason, after no more than 10 minutes of test tones (from 25hz to 40hz) at around 75% volume the amp goes in and out of protect mode. All we were trying to do was loosen the woofers up a bit. Car was started, and gains weren't even at full potential.

Fuse holder w/ voltage display states that the voltage was around the 11.8V range before it went into protect (cars heater was on, voltage taken at rear batt)

What do you mean not at full potential? How did you set the gains?

Maybe the amp doesn't likes 11.8V or lower, and draws more current that's (probably) why it heats up and maybe clips and shuts itself off.

Gains were set with a multimeter, and so once we saw what full potential was (around the 3/4 gain area) we back it down to around 1/2 gain (because we want to break in the woofers slowly in these cold months) That 11.8V was the lowest it dropped at a 45hz test tone, which jumped right back up to 12V and up to 12.2V with the car's heater off

Setting gains with a multimeter is a bad idea...

You are probably over driving the amp with the headunit, a combination of the low voltage issues...

If it is getting hot you may very well have it wired wrong..

So please explain that when this amp was also used in my friends truck, who has a 4 batt system, where the voltage never dips below 13V, did the amp go into protect after 10 minutes, and still start heating up after 5 minutes. Subwoofer used was a BTL dual 1 ohm

Clipping is the problem which everyone keeps trying to tell you, or the amp maybe damaged (only things that make amp hot are : clipping, low voltage, wrong ohm load, not a well vented environment or damaged amp).

Clipping is the problem which everyone keeps trying to tell you, or the amp maybe damaged (only things that make amp hot are : clipping, low voltage, wrong ohm load, not a well vented environment or damaged amp).

What I dont understand is that the woofers arent even moving, nor am I even close to what the gain should be set at, yet the amp is heating up so fast and going into protect

If we do managed to take a look at the inside of the amp, what should we look for? Things such as burned areas? Loose parts?

Yeah looked for cracked parts, burnt parts (or are discolored), if the amp has been repaired before then look for a poor job on fixing amp, loose parts, etc.

Could also be something in the amp, maybe the amp is vibrating so much something in the amp came loose.

just get a diff amp for the time being and have at it

SO...

My friend came by and we opened up the amp. Only thing i noticed is that alot of the internals have a white paste on them (i'm guessing some sort of thermal paste). After a good 10 minute look, we found nothing that looked burnt, fried, or anything abnormally loose.

So far it has only gone into protect once today after a good 15 minute drive with music. We are considering creating a plexiglass cover plate, with a small computer fan on it, either blow air out or sucking air in, and then reverse mounting the amp.

Do both when it comes to fans, one blowing on the amp and the other sucking the hot air away and that should work. Where is the amp mounted?