I'm having issues with low subwoofer output

[Jacob Pierznik]

Hello, I have a 2007 Honda accord exl 4cyl with a sound system I've always had trouble with and I'm stumped as to what the issue is. I have a kenwood dmx809s, a skar 800i.d amp and a brand new skar svx10d2 wired to 1 ohm for 800watts, I also have the big 3 kit as well. I've had this low subwoofer output issue for a long time and always thought it was the android headunit I used to have so I changed it, but even after that I'm having issues still. Im having a voltage drop issue and I even re did the ground today since the shop that originally did it just used a self tap screw. I even tested the location with a multimeter and used a nut and bolt but still no luck. At high volume I drop from 14.3 to like 12.8 volts at the amp, but it doesn't make any sense to me being that the car has a 130 amp alternator and I only have an 800watt amp that I'm having voltage drop. Any help with this issue is greatly appreciated .

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[spokey9 5,000+ posts]

What kind of battery are you using and how old is it?

 

[Jacob Pierznik]

What kind of battery are you using and how old is it?

It's a shiruken bt-60 1500watt and it's only a little over a year old. It's also my only battery.

 

[1aespinoza Premium Member]

Any help with this issue is greatly appreciated

Is the engine block grounded to a strut tower?

 

[Jacob Pierznik]

Is the engine block grounded to a strut tower?

There isn't any grounds on the strut tower.

 

[1aespinoza Premium Member]

There isn't any grounds on the strut tower.

The strut towers are reinforced points of the chassis therefore making them perfect grounding points. You can use the strut bolts as clamping just make sure the paint is sanded completely.

 

[dragon.breath 10+ year member]

You shouldn’t be having trouble with output at 12.8 volts. Under normal circumstances, I doubt that you would even be able to hear the difference between 14.3 and 12.8.

 

[Blackout67]

Could be a bad voltage regulator cutting output from the alternator. Wouldn't be unheard of for one to go out on an almost 20 year old car

 

[Jacob Pierznik]

If it's dropping as low as 11.8v after I checked again, would that be the cause of the low output issue or could it still be something else?

 

[some dude]

Is your amplifier gain set correctly?

Are you ever clipping?

Does the sub move a fair amount?

What's the A/C voltage of your amplifier speaker wire terminals when you turn up the volume?

 

[Jacob Pierznik]

Is your amplifier gain set correctly?

Are you ever clipping?

Does the sub move a fair amount?

What's the A/C voltage of your amplifier speaker wire terminals when you turn up the volume

The gain was set by the shop when I had the android unit so I don't know how they set it when I had to use bass boost, loudness, and a setting called smart bass to get any output.

I don't know if I clip on the setup with the svx10 or not with the headunit I have in the car now because I got 2x12s in the car now and I don't know if they turned the gain up to compensate for low output or not because back when I had my old headunit the shop said that my svx10 probably had low output because it was maxed out so I got the 12s which I have sent my amp into protect mode a couple times with because the amp gets hot after a while. I want to put the brand new svx10 I have in to replace my old one I broke before due to the incorrect settings I had to use before, but it has the low output when I put it in back in after the new headunit.

The svx 10 doesn't seem to move anywhere close to where it should at any volume, but it moves a decent amount at high volumes to where I know I have it wired in phase. Low volumes are non existent pretty much.

I got my readings of anywhere from11.8v to 12.8v on high volume from the power and ground terminals on the amp. Should I retest on the speaker terminals instead or does it not make a difference?

 

[some dude]

Test the speaker wire terminals.

Turn it up fairly high, like 70% maximum volume. Take A/C voltage reading on terminals. Let us know what it's highest repeating values are. We can calculate how many watts the amp is putting out.


Also test the ohms (resistance) across the same terminals with the amplifier off.

 

[Jacob Pierznik]

Test the speaker wire terminals.

Turn it up fairly high, like 70% maximum volume. Take A/C voltage reading on terminals. Let us know what it's highest repeating values are. We can calculate how many watts the amp is putting out.


Also test the ohms (resistance) across the same terminals with the amplifier off.

So I couldn't get any readings on A/C at all and I couldn't get any readings on D/C at the speaker terminals on the amp, but the power terminals on the amp I could only get a D/C voltage which was 14.1 at idle and with music playing at 70% on heavy bass notes it drops immediately to anywhere from 13.5v to 11.7, I would say 12.0v to 12.5v are the highest consistent values I see when the volume is up high, but it's all over the place when the volume is up high. I also tested the resistance of the speaker terminals at the amp and got 1 ohm.

 

[SbassLaser]

You won't get a DC reading at the speaker terminals because it's not putting out DC voltage to the speaker. Speakers only work with AC voltage, which is why some dude told you to measure AC voltage.
The amplifier will be putting out an AC signal to the speakers, and based on the voltage of that signal we can figure out how many watts you're getting to the speakers. If you're testing it with music playing it will probably be all over the place and not give you a good reading. Try it again with a 40 hz test tone and you'll see a consistent reading.

 

[Jacob Pierznik]

You won't get a DC reading at the speaker terminals because it's not putting out DC voltage to the speaker. Speakers only work with AC voltage, which is why some dude told you to measure AC voltage.
The amplifier will be putting out an AC signal to the speakers, and based on the voltage of that signal we can figure out how many watts you're getting to the speakers. If you're testing it with music playing it will probably be all over the place and not give you a good reading. Try it again with a 40 hz test tone and you'll see a consistent reading.

I'm getting a reading of 38.2v a/c steady at the speaker terminals with a 40hz test tone playing at 70% volume.