After about 30 mins or so the sub just starts to pich in a low sounding hum rather than responding to the amp with any bass. I then turn the power to the sub off which creates a thumping boom and the turn it back on again and its fine for about 30 mins again...any ieas ?

It sounds like the problem is not with your VR-606. If you hear a hum from the sub, the problem is more likely to be in the sub's built-in power amplifier. However, it is worth resetting the amplifier to factory presets. To do this, unplug the power cable from the mains supply and reconnect whilst holding down the power on/standby key. If the hum persists, connect any powered speaker to the sub-out socket, power on and listen for the hum. If no hum then suspect the powered sub amp. Turn the sub on with no connection to the Kenwood VR-606. If hum persists, the sub has a problem and will need to be replaced or repaired. By the way, you said there is a low frequency hum through the 'speakers' for about 30 mins. Is that all speakers or just the sub? Hope this helps.
Cheers, Don.

1st have your subs facing inwards towards the front of the car, not facing out the boot, This creates a better bass.

Wire 1 sub to one channel and the other sub to the other channel.

Turn down your gain as low as possible and then power everything up.

turn volume to desired loudness and then start turning up the gain slowly, if distorts a little turn in back down a notch.

avoid using bass boost, I agree it sounds great but it puts more strain on your amp and shortens its life.

after sorting out your gain, tweak all others until sound is bassy and clear with no distortion.

If you would like to use bass boost, turn on bass boost first, then up your gain etc.

When i hooked up my bass knob the amp made my subs hum i unhook the rca but still humming unhook bass knob still hummin

First off, you need to disconnect your battery immediately.. The reason for the feed back is you have a hot wire touching ground somewhere....probably a large sub speaker cable.....What will happen is the power going from the amp to the speaker or from the head unit to the sub will come into contact with bare metal and feed that current back into the system through the isolated ground. This will either reduce sound, or when the power is high enough, turn from a low hum to a heavy crackle. now if it crackles with the bass, more than likely its in your sub/amp configuration....if its constant or completely random then it could be anywhere in the system. check for bare, broken, or exposed wire.
GOOD LUCK AND PLS RATE THIS POST!!!!

it sounds like a bad sub woofer amplifer, as the unit heats up the capacitors start to leak and the amp will try to shut down. it would depend on how hard you are driving it, (heavy bass versus light bass) that would cause it to fail sooner than later. You need to replace the internal amp

Neither the amp or the sub have grounded power cords.

I have discovered the ML Dynamo takes about 30 minutes to switch to standby in auto mode.

With speaker level inputs connected to the Onkyo A807 amp, both units powered from the same wall outlet, Dynamo sub on Auto, the sub hums for about half an hour after the Onkyo is switched off, then the sub goes quiet. Not so good.

I connected a bonding wire between the two units on 3_7_09. If I smoked some old audio gear I could just look at that as an opportunity, right?

Works fine. Now I have the ML powered from the wall and working normally.

there has to be sumthn hooked up wrong bc i have had same problem with my 12' subs but it was simply a matter of my rca jacks but sense you have checked them try rewiring the speakers if that does not work then your rca module may be burned out within the amp..iso then check the amp by taking the cover off and making sure nuthn is burned on the inside.or if any wires are loose or touching.

kicker subs arnt ment to hit the lowest bass, unless you go spend a **** load of money, im talking 3000 wat amp, ant some 15' or bigger subs. the most commen kickers are 12' subs, so im asuming you have 12' subs, if not, this (said lightly) should work. try turning the bass boost screw on the amp to the middle of its turning range. this will offer the greatest balance between high and low bass. if you want more low bass, turn it past half. if you want more high bass, turn it down. i have mine set to mid range, but i also recently purchased 2 18' kickers. with every new set of subs, you should spend at least 15 min tuning the amp to get the best performance. every sub is different. hope this helps, good luck.

Hi Saint108. You're describing it well, and i know what the problem is already. The MA audio amp, can't hold with a 2 ohm load. It's too low for that amp, that's for sure. Those are budget amps and they are not well built enough to handle low ohm setups like that. It's overheating and there's no ways around it.. Other than wiring your subs differently ! Just wire your sub directly (not in parallel) in a 4 ohm load, you will notice it will stop overheating that much. Do it quick, you'll most likely fry your amp giving it such hard work !! The HUM you're hearing could be related to it also. Try that, and keep me posted on the status. Thanks ! Cheebster.

could be low current ,disconnect all power including ground for 20min N.B most amps will seem to be shorted at output but this is normal due to damping ratio.