Quick Load Q, Tantrum bridged @ 2

[ajaye]

OK right now I have 1 12" that is dual 4 ohm coils. I'm feeding a Tantrum 500.2 from my Clarion EQS746 Subwoofer outputs since it has a sub level control. Its lowpassed at 90 right now by the Clarion ouput (that's a whole different discussion, other amp has fixed high pass @ 80, its getting replaced w/ my ZX) and is feeding the Tantrum inputs with xover bypassed. I have the amp bridged with coils wired in parallel. I'm getting lights dimming with it loud which I really feel shouldn't be happening, although my alternator is a $20 junkyard job, it shows 14.4ish when the car is running and the battery is pretty much brand new and specs for the car. I've done big 3, I've got like 18" tops of 8 gauge power wire from distro to Tantrum, I've changed the ground to 4 gauge since I lengthened it to ground at an optimal chassis connection.

Is there anything to gain efficiency-wise by wiring each coil to a channel from the amp? The issue is I like the sub level control on the preamp, so the only way I can figure to do this and keep the control would be run a Y cable from the sub outputs to sum the L+R preamp signal, run the signal on a single RCA to the amp, then use another Y cable to feed both of the amp's inputs. Seems like a pain but I'm willing to try it if it will somehow help with overall current draw showing the amp 4 ohms x 2 vs bridged 2ohms.

[Bfowler]

you're running a 500.2 at 2ohms bridged with 8awg wire from distro to the amp? you are lucky it didnt melt then

that amp isnt made for that load, let alonf without dedicated 4awg and a cap.

you will cut your power in half, but you should run that sub with its coils in series for 8ohms until you get your 2ohm stable zx in

[trickyricky]

Agree with bfowler.... bridge the amp at 8ohms and you will be good to go, until you find a 2ohm mono stable amp.

[ajaye]

you're running a 500.2 at 2ohms bridged with 8awg wire from distro to the amp? you are lucky it didnt melt then

that amp isnt made for that load, let alonf without dedicated 4awg and a cap.

you will cut your power in half, but you should run that sub with its coils in series for 8ohms until you get your 2ohm stable zx in

Well the manual says min bridged load is 2 ohms and max power bridged load is 4 ohms, and I've had it fused with a 40 amp fuse just in case. Certainly not ideal but its been way too cold and I drive it way too little to do anything else recently. I guess I need to hurry up on the new distro and get everything swapped and rewired. I was really hoping to keep the Tantrum for sub duties and use the ZX 350 for fronts...so I assume you think I'd be better summing the signal and running 1 coil/channel in that case then?

[ajaye]

Agree with bfowler.... bridge the amp at 8ohms and you will be good to go, until you find a 2ohm mono stable amp.

Yeah the problem is right now I have no extra money. Like I haven't even had enough to order caps and diode for that ms275 I got. I have 3 amps sitting here in my room and the 2 in the car and of course the only 1 that is 2 ohm stable is the 1 I really wanted for front stage. I may go putz around tonight and see how things sound w/ coils in series, I'm not winning any spl contests so maybe it will do the job like that. Getting things crossed a bit lower on the sub once I have some more control over the high pass on the other amp should help too I would think

appreciate the input guys.

[Mr. Wild]

Your sub will sound much better too, if you run it at 8ohm bridged. Especially if its ported.
No need to touch the signal cables, just put the subs coils in series and that will sum L+R channels.

[Bfowler]

you're running a 500.2 at 2ohms bridged with 8awg wire from distro to the amp? you are lucky it didnt melt then

that amp isnt made for that load, let alonf without dedicated 4awg and a cap.

you will cut your power in half, but you should run that sub with its coils in series for 8ohms until you get your 2ohm stable zx in

Well the manual says min bridged load is 2 ohms and max power bridged load is 4 ohms, and I've had it fused with a 40 amp fuse just in case. Certainly not ideal but its been way too cold and I drive it way too little to do anything else recently. I guess I need to hurry up on the new distro and get everything swapped and rewired. I was really hoping to keep the Tantrum for sub duties and use the ZX 350 for fronts...so I assume you think I'd be better summing the signal and running 1 coil/channel in that case then?

you dont need to change anything in your signal path. just wire the sub's coils in series inside the box and you will be set

[ajaye]

you dont need to change anything in your signal path. just wire the sub's coils in series inside the box and you will be set

Your sub will sound much better too, if you run it at 8ohm bridged. Especially if its ported.
No need to touch the signal cables, just put the subs coils in series and that will sum L+R channels.

I'm a little slow sometimes. Stereo to each coil would be a more complicated way of doing the same thing as bridged to coils in series. Thanks for saving me the headache guys.

[ajaye]

see what I mean I can't even say what I'm thinking sometimes. 2 channels of mono signal w/ 1 channel per coil, not stereo to each coil.

[trickyricky]

Since its subs you want the signal to be mono. Therefore having the subs bridged in series gives you an 8ohm mono load (which the amplifier sees the same as a stereo 4ohm load...as if you where to wire each sub to each channel). Which is way better on the amplifier than a 2ohm mono load (1ohm stereo), not saying the amplifier can handle it, its just a matter of time of the temp protection circuit kicking in.

[ajaye]

Just drove home at like 8am from the club trying to implode my eardrums with Songs In the Key Of Life so I'd say bridged @ 8 sounds just fine. Clearly not stressing the electrical like before either. Thanks dudes.