syn6 noise

[kiwia]

i have a syn 6 that i just got back from wet sounds where they checked it for noise from pumps lights etc, they told me it was all good, refitted amp with new rca cables & alls good, no more outside noise. Then i crank up the volume & it starts making a loud noise like it will blow out the speakers, sometimes i can turn the volume down & it will stop, other times i turn the volume off & the noise is still there & its so bad the dog will run & hide, thanks for any help

[Truekaotik]

Eliminate the head unit by using a 3.5mm to RCAs and go directly to amplifier to see if persists?

[chpthril]

Give us some more details about the system.

Are there other amp? What are they?

What speakers are being driven by the suspect amp and the other amps?

Any difference in the issue with the engine running running?

Described the noise?

[kiwia]

there is a syn2 for the tower with two rev8s, i disconnected the syn6 & the tower speakers sound great, so then disconnected the syn2 & still have same problem, syn6 is running 10af sub bridged & 4 xs650 on channels 1-4, i tried disconnecting speakers one at a time, on different, i did not try with engine running but had a battery charger on it, the noise hard to explain but very loud popping or thumping noise on & off

[chpthril]

With the battery charger off and the system off, measure the voltage at the Syn-6 power cable terminal. The power the system off and measure again. Low voltage will make amps to strange things and the Class-A/B Syn-6 is a beast and may be effected by the voltage level but not the Syn-2.

[kiwia]

will check voltages today & get back

[kiwia]

checked voltages, all off at battery 12.46, at amp12.46, radio & amp on 12.2 at battery, 12 at amp. Power at amp drops to 10.8 when it makes noise & 11.75 at battery. With 10amp charger on battery amp drops to 10.4 when it makes noise & battery to 11.4

[chpthril]

When the issue happens, you've got nearly a 1 volt drop. Thats not good. This could be a combination is weak battery, which 12.46V and its been on a charger is not good, bad amp cable, and possible something in the amp spiking current draw.

Do i suspect a bad battery, yeah
Do I suspect cable issue, yep
Can i rule out an issue with amp, not yet.

Next, I would pull the turn-on wire from the Syn-2, to leave all the battery juice for the Syn-6.

Next, swap the RCAs for the Syn-2 and Syn-6. Now, the Syn-6 will have 2 sets going to it, one for the sub, which we dont need to mess with, and the other set for full range in-boats chnls. Since the noise is not present in the Syn-2, we can assume that its current RCA set is good and the signal from the head-unit is good. This is going to be tough to do, but I want to swap these at the amp, not head unit. If needed, use a test set of RCAs to just lay in from the amp to head-unit, but use the head-unit outputs that are going to the Syn2.

[kiwia]

i am using a kicker zxmrlc, so i only have one set of rcas from hu to zxmrlc & one set from that to each amp, i have disconnected the power to the syn2 & by passed the zxmrlc with new good quality rcas straight to syn6, still the same

[Truekaotik]

Your battery sound cycled and needs replaced most likely. You should never run a amplifier below 12v...
Just because a battery holds voltage above 12 resting doesn't mean it's good. once a load is placed on a battery it shows its condition fast.. I say replace battery first..