SWR's cut out at high volumes
03-26-2009, 04:40 PM
#11
Yankee
Join Date: Oct 2003
Posts: 3,599
I haven't had a low voltage issue to my amps (verify the terminal voltage) but maybe just maybe a run of power wire carrying the - power in addition to the + run you already used is in order. When I had a 1.5k amp I used a second battery as well.
03-26-2009, 07:46 PM
#12
I have a HO alt on my Focus SVT ... but it is limited to the factory voltage 13.5v ... darn you ford.
I haven't had a low voltage issue to my amps (verify the terminal voltage) but maybe just maybe a run of power wire carrying the - power in addition to the + run you already used is in order. When I had a 1.5k amp I used a second battery as well.
I haven't had a low voltage issue to my amps (verify the terminal voltage) but maybe just maybe a run of power wire carrying the - power in addition to the + run you already used is in order. When I had a 1.5k amp I used a second battery as well.
03-27-2009, 12:00 AM
#13
Status update:
Verified subs are indeed wired at 1 Ohm with a multimeter
Installed 5 Farad cap, lights don't dim anymore
but amp still kicks off if I'm listening to it really loud for a long period of time.
My amp is still mounted upside down. Is there any reason other than asthetics why I wouldn't screw it into my sub box? Also assuming my screws don't pierce the inside of the box.
Thanks!
Verified subs are indeed wired at 1 Ohm with a multimeter
Installed 5 Farad cap, lights don't dim anymore
but amp still kicks off if I'm listening to it really loud for a long period of time.
My amp is still mounted upside down. Is there any reason other than asthetics why I wouldn't screw it into my sub box? Also assuming my screws don't pierce the inside of the box.
Thanks!
03-27-2009, 05:10 AM
#14
Yankee
Join Date: Oct 2003
Posts: 3,599
The amp may NEED to be mounted differently, remember heat rises in air and having the heat sink where it can absorb the heat is a good thing...the output transistors are mounted on the heat sink to directly remove the bulk of the heat so most of the heat is removed by conduction, I am addressing convection
not all amps have this issue as designs vary and some use cooling fans
not all amps have this issue as designs vary and some use cooling fans
03-27-2009, 08:23 AM
#16
Status update:
Verified subs are indeed wired at 1 Ohm with a multimeter
Installed 5 Farad cap, lights don't dim anymore
but amp still kicks off if I'm listening to it really loud for a long period of time.
My amp is still mounted upside down. Is there any reason other than asthetics why I wouldn't screw it into my sub box? Also assuming my screws don't pierce the inside of the box.
Thanks!
Verified subs are indeed wired at 1 Ohm with a multimeter
Installed 5 Farad cap, lights don't dim anymore
but amp still kicks off if I'm listening to it really loud for a long period of time.
My amp is still mounted upside down. Is there any reason other than asthetics why I wouldn't screw it into my sub box? Also assuming my screws don't pierce the inside of the box.
Thanks!
03-27-2009, 09:07 AM
#17
Will check voltage tonight. @work currently.
Also, I think I'll try reorienting my amp so that it faces upwards however I've got limited space in my hatchback. I may end up just mounting it on the piece of hard plastic that seals off the top of the trunk space from the rest of my car. It's currently mounted underneath it.
Also, charging my cap was kinda freaky lol. Not the kinda thing you want to be doing after a long *** day at work while being really tired.
I was sitting on my back seat with the hot lead and the resistor and was getting close to doing it saying to myself 'please don't blow up in my face, please don't blow up in my face' over and over again.
But I started charging my cap, no crazy arcing or anything unpleasant, I just held it there till the light on my 'resistor' went out and the battery voltage leveled out and away I went.
Also, I think I'll try reorienting my amp so that it faces upwards however I've got limited space in my hatchback. I may end up just mounting it on the piece of hard plastic that seals off the top of the trunk space from the rest of my car. It's currently mounted underneath it.
Also, charging my cap was kinda freaky lol. Not the kinda thing you want to be doing after a long *** day at work while being really tired.
I was sitting on my back seat with the hot lead and the resistor and was getting close to doing it saying to myself 'please don't blow up in my face, please don't blow up in my face' over and over again.
But I started charging my cap, no crazy arcing or anything unpleasant, I just held it there till the light on my 'resistor' went out and the battery voltage leveled out and away I went.
03-27-2009, 09:51 AM
#18
2000 Watt CAFz'r
Join Date: Jan 2001
Posts: 2,026
I don't think it is a voltage issue
I firmly believe it is a heat issue.
Reasons why:
1) When amps go into thermal protect, it can take them anywhere from 30 seconds to 5 minutes to cool down enough before they turn on again. Low voltage will cause the amp to turn off and on again from .5 seconds - 2 seconds - It won't take any longer for the voltage to build up even when it is refueling a cap.
2) I have mounted amps upside down and each time I've done it I've run into similar problems. Some of the amps were very hot to the touch while others weren't. The problem was always solved by mounting right-side up.
The amp probably doesn't feel warm because all of the heat is staying inside the amp causing the circuit board to get hot too early, and the thermal sensor to engage. Now, the amp might not even be dangerously hot yet, but the amp is designed for the heat to travel up. So perhaps the thermal sensor is at the bottom of the amp and engages when it gets hot enough for the heat to make it down to it. If this is a possibility, then mounting the amp upside down will have the opposite effect. Heat will rise up to the sensor now, getting the sensor to trip when it really isn't all that hot.
Before you do any other changes or upgrades, flip the amp over.
I firmly believe it is a heat issue.
Reasons why:
1) When amps go into thermal protect, it can take them anywhere from 30 seconds to 5 minutes to cool down enough before they turn on again. Low voltage will cause the amp to turn off and on again from .5 seconds - 2 seconds - It won't take any longer for the voltage to build up even when it is refueling a cap.
2) I have mounted amps upside down and each time I've done it I've run into similar problems. Some of the amps were very hot to the touch while others weren't. The problem was always solved by mounting right-side up.
The amp probably doesn't feel warm because all of the heat is staying inside the amp causing the circuit board to get hot too early, and the thermal sensor to engage. Now, the amp might not even be dangerously hot yet, but the amp is designed for the heat to travel up. So perhaps the thermal sensor is at the bottom of the amp and engages when it gets hot enough for the heat to make it down to it. If this is a possibility, then mounting the amp upside down will have the opposite effect. Heat will rise up to the sensor now, getting the sensor to trip when it really isn't all that hot.
Before you do any other changes or upgrades, flip the amp over.
03-27-2009, 09:59 AM
#19
2000 Watt CAFz'r
Join Date: Jan 2001
Posts: 2,026
One other thing, the SWRs might have a slightly lower re than the pioneers so the amp may see a slightly lower impedance which might be the "straw that broke the camels back"
It was mentioned above that some voice coils actually meter less than their rating (ie a 4 ohm coil is really 3.6 ohm on a meter). My experience is that a vast majority of subs are like this. But we need to remember that dc resistance is different than impedance. Multimeters measure dc resistance, while impedance would be what the amp actually sees. Now, I might be a bit off with this, but my understanding is that impedance represents the "musical average" resistance of a sub. The resistance will be very different depending on the note, or notes played. but generally speaking, across the frequency spectrum it will be pretty close to 4 ohm.
An amps specs are sufficient to match a subs specs measured in impedance. While the re (DC resistance) might be lower or higher, the amp will see what it needs to with impedance.
The SWR are not overloading the amp . . . I'm convinced it is the heat.
It was mentioned above that some voice coils actually meter less than their rating (ie a 4 ohm coil is really 3.6 ohm on a meter). My experience is that a vast majority of subs are like this. But we need to remember that dc resistance is different than impedance. Multimeters measure dc resistance, while impedance would be what the amp actually sees. Now, I might be a bit off with this, but my understanding is that impedance represents the "musical average" resistance of a sub. The resistance will be very different depending on the note, or notes played. but generally speaking, across the frequency spectrum it will be pretty close to 4 ohm.
An amps specs are sufficient to match a subs specs measured in impedance. While the re (DC resistance) might be lower or higher, the amp will see what it needs to with impedance.
The SWR are not overloading the amp . . . I'm convinced it is the heat.
03-27-2009, 11:11 AM
#20
it's possible that the amp being mounted upside down and not feeling very warm, may be overheating inside and can't dissipate the heat. I'd try mounting it right side up temporarily to see if it still does it.
If the kenwood was powering the pioneers in 1 ohm mode previously...then it's 1 ohm stable.
If the kenwood was powering the pioneers in 1 ohm mode previously...then it's 1 ohm stable.
