Strapped SAZ-3000D's engine noise

[hispls 23]

Well,As I mentioned here. I did get a chance to hook up the second SAZ 3000D today.

I measured a nominal 3 ohm load with each coil series and each woofer parallel to eachother. Anyway in theory there would be something to gain (stability if nothing else) running these subs strapped to the 3 ohm load.

Initial testing reveals noticeable gain in output and in SQ. BUT there's a nasty engine noise from the subs now. Seems to not be effected by the gain.

Both amps connected to the same battery (in the trunk) with <3ft lengths of #1/0 guage. resting at 12.6V car off (total 3 batteries in car). RCA is a 1.5ft piece of high qualtiy patch cable.

Now if I ONLY remove the speaker leads, and move the main source RCA to either amp both run dead quiet.

Any ideas of a fix for this? I would really like to keep the pair of these for the extra power and to run them in a more stable impedence. I'm also planning to get a 3 ohm TC LMS driver that I would like to have these two strapped into for playing around with so being able to drive 4KWish into a 3 ohm load (WITHOUT noise) is now my goal.

[johnecon2001 82]

The strapping, the 3 ohms, even the amps them selves have nothing to do with your engine noise.

Try removing the RCA's from the amp, is the noise still there? If it is, the problem lies with your amplifier ground. If its gone, the problem lies with the head unit.

[hispls 23]

The strapping, the 3 ohms, even the amps them selves have nothing to do with your engine noise.

Try removing the RCA's from the amp, is the noise still there? If it is, the problem lies with your amplifier ground. If its gone, the problem lies with the head unit.

Both amps are dead quiet when not strapped. Both grounds straight to the same negative battery terminal <3ft from the amps on 1/0 guage.

Will play more tomorrow in the daylight.

[sqjeep 9]

Well,As I mentioned here. I did get a chance to hook up the second SAZ 3000D today.

http://www.soundsolu...r-not-to-strap/

I measured a nominal 3 ohm load with each coil series and each woofer parallel to eachother. Anyway in theory there would be something to gain (stability if nothing else) running these subs strapped to the 3 ohm load.

Initial testing reveals noticeable gain in output and in SQ. BUT there's a nasty engine noise from the subs now. Seems to not be effected by the gain.

Both amps connected to the same battery (in the trunk) with <3ft lengths of #1/0 guage. resting at 12.6V car off (total 3 batteries in car). RCA is a 1.5ft piece of high qualtiy patch cable.

Now if I ONLY remove the speaker leads, and move the main source RCA to either amp both run dead quiet.

Any ideas of a fix for this? I would really like to keep the pair of these for the extra power and to run them in a more stable impedence. I'm also planning to get a 3 ohm TC LMS driver that I would like to have these two strapped into for playing around with so being able to drive 4KWish into a 3 ohm load (WITHOUT noise) is now my goal.

Question to the part in red. Are the speakers disconnected when you run the setup non strapped?? Also do you have pin connectors on the end of the speaker wire?? Cause my ESX 60.4 did a similar sound and all it was was the set screw was destorying the wire. So i added pin connectors and the sound vanished.

[hispls 23]

Well,As I mentioned here. I did get a chance to hook up the second SAZ 3000D today.

http://www.soundsolu...r-not-to-strap/

I measured a nominal 3 ohm load with each coil series and each woofer parallel to eachother. Anyway in theory there would be something to gain (stability if nothing else) running these subs strapped to the 3 ohm load.

Initial testing reveals noticeable gain in output and in SQ. BUT there's a nasty engine noise from the subs now. Seems to not be effected by the gain.

Both amps connected to the same battery (in the trunk) with <3ft lengths of #1/0 guage. resting at 12.6V car off (total 3 batteries in car). RCA is a 1.5ft piece of high qualtiy patch cable.

Now if I ONLY remove the speaker leads, and move the main source RCA to either amp both run dead quiet.

Any ideas of a fix for this? I would really like to keep the pair of these for the extra power and to run them in a more stable impedence. I'm also planning to get a 3 ohm TC LMS driver that I would like to have these two strapped into for playing around with so being able to drive 4KWish into a 3 ohm load (WITHOUT noise) is now my goal.

Question to the part in red. Are the speakers disconnected when you run the setup non strapped?? Also do you have pin connectors on the end of the speaker wire?? Cause my ESX 60.4 did a similar sound and all it was was the set screw was destorying the wire. So i added pin connectors and the sound vanished.

LOL, yes speaker connected, I meant removed the - to - wires. and the RCA between master out and slave in. Hooking up speaker to either amp.

No pin connectors, but again, just one amp or the other and no noise. Also no isses with protect mode as others mentioned could be a problem, output is fantastic.

Again, will test more in the daylight tomorrow.

[shizzzon 461]

maybe try different strapping rca cables...

That's the only thing different...

From what i remember, use some basic cables, most high end cables tend to have problems sometimes.

[hispls 23]

More testing today. Tweaking ground does nothing.

RCA from HU removed = still engine noise

Both amps hooked up but not to eachother = no noise

RCA between amps removed = no noise

tested 3 different type/size/brand RCA's seemed to have no effect.

This noise is horrid someone please help, I can't be the only one to have had this problem. Running each amp separately to each woofer is out since I need the subs level matched.

[sundownz 197]

You can gain match them separately -- if you are within 0.1v or so it's perfect.

Generally if there is a noise when strapped it can be resolved by changing the RCA cable between the amps.

[hispls 23]

You can gain match them separately -- if you are within 0.1v or so it's perfect.

Generally if there is a noise when strapped it can be resolved by changing the RCA cable between the amps.

I think this would be very difficult with tolerances. Also would make using remote knob a bit tough. Any particular brand/style of RCA that is known to work? If you have a 2 footer you could ship me I'd pay if it works.

So far used :

Stinger

Radio Shack (middle of the road)

Tributary

Might add that the noise begins AS SOON AS the center pin makes contact inside the female on the amp.

Edited September 6, 2009 by hispls

[sundownz 197]

Generally the Radio Shack ones work great -- the really cheap ones.

For two amps gain matched you can use a telephone cord Y-Splitter to control both.

It's really not that hard to get them matched close enough that there is effectively no difference -- we matched six amps in the 160 dB @ 34 Hz build

[hispls 23]

Found some cheap RCA's....no help there. Will attempt to level match for now, but would love to get this straightened out to run to a single 3 ohm coil LMS driver.

[sundownz 197]

Your RCA connector may be loose or cracked - that is a thought.

[team nemesis steve 0]

Try using the ole cheap wal-mart scoche rca's. They seem to work for me perfect. Also, are you using any type of x-overs, line drivers or possibly a maxx link in conjunction with the amplifiers? The maxx link added awful engine noise to my set-up and I removed it.

[hispls 23]

Nothing else in signal path.

Further testing reveals it may be an issue with my electrical system (though I'm still not sure why it doesn't reveal itself with the amps as individuals?). After some highway driving and a full charge on batteries the noise seems to quiet right down.

WIll have all my batteries tested this week and probalby test my alt as well (though that's only 1 year old). Anyway these amps are pretty ballsy it's getting loud enough that I feel it's actually getting dangerous and I can tell you moderation in things has never been my long suit.

Thanks for all the help fellas. I gotta say these amps are as good as anything in their class and the support here is right up there with the best in the industry.

[hispls 23]

Update. Picked up a new alternator and took my old one into a local shop that re-builds.... Sure enough old alt has a smoked diode in the rectifier and with the new one there isn't a hint of noise.

Dunno if this'll help someone sometime but just throwing it out there.

Having the old alt re-built so I have a backup when I smoke this one.

[jcarter1885 995]

Update. Picked up a new alternator and took my old one into a local shop that re-builds.... Sure enough old alt has a smoked diode in the rectifier and with the new one there isn't a hint of noise.

Dunno if this'll help someone sometime but just throwing it out there.

Having the old alt re-built so I have a backup when I smoke this one.

Glad to know everything was ok and that is some good troubleshooting information to know also about engine noise coming from a bad alternator (in case all others methods were tried).

[sundownz 197]

Thanks for the update