[akg7091]

I have a question to ask from all the gurus.

I have a pioneer 306 DVC sub and 2 mono amplifiers, a sony and a blaupunkt.

I am currently using the 306 with both coils in parallel ( 2 ohm load ) with the blau amplifier. However after approx 30 minutes of use the amplifier trips due to overheating.
I was wondering if it is possible to use both of the amplifiers I have and power one coil through each.
Is it possible ?

SONY amp : 200@4, 400@2
Blau amp : 400@4 , 650 @2

Both ratings are at 14.4v according to the manuals

Also, is it possible to chain amplifiers to increase the output ?

Thanks

[panky12345]

blau amp that you're using is a 4 channel amplifier, thats stable in 4 ohm in bridged mode.

You can very well connect your both the coils via different amps....but your 306 has a nominal impedance of 400 W RMS only, if you use both amps, you'd be pushing on 1050W RMS (thereotically!) and blowing your sub. You've used 306C instead of 306DVC in case you wanted to use it with blau amp.

[navin]

Originally Posted by akg7091

I am currently using the 306 with both coils in parallel ( 2 ohm load ) with the blau amplifier. However after approx 30 minutes of use the amplifier trips due to overheating.
I was wondering if it is possible to use both of the amplifiers I have and power one coil through each.
Is it possible ?

SONY amp : 200@4, 400@2
Blau amp : 400@4 , 650 @2

Both ratings are at 14.4v according to the manuals

Also, is it possible to chain amplifiers to increase the output ?

Thanks

Try using just the Blau amp but turn the gains down a bit. if the Blau amp is table at 2 ohms it should work.

You can connect 2 different amps to 2 differnet voice coils of the same sub but you will have to carefully match gains so that both amps are pushing the about same watage.

[panky12345]

(my poor knowledge) Do we have certain 4 channel (budget) amps that are 2 ohm stable in bridged mode. I know certain expensive amps that are, but not sure on the budget range.

[akg7091]

Originally Posted by panky12345

blau amp that you're using is a 4 channel amplifier, thats stable in 4 ohm in bridged mode.

You can very well connect your both the coils via different amps....but your 306 has a nominal impedance of 400 W RMS only, if you use both amps, you'd be pushing on 1050W RMS (thereotically!) and blowing your sub. You've used 306C instead of 306DVC in case you wanted to use it with blau amp.

Blau is a mono amplifier ( class AB ), capable of 650@2ohm rms < .003%THD
Sony is a mono ( class D ) capable of 400@2ohm < 1 % THD

I have set the blau amp using the DMM and the measured voltage at the output terminals is approx 28.3 volts ( or 400 watts at 2 ohms ) and it trips after about 50 minutes of use.

Are you sure it won't damage the sub and/or the amps if I drive each coil from different amplifier and set the gains on each amp using the DMM ?

I can give it a try after 26th sep when I am free. Till then I am busy due to exams

[akg7091]

check this link for specs on the blau amp Blaupunkt THA1400 amplifier

Also, can one of the mods pls edit my previous post. I mentioned THD as <.003%. It is actually < 0.03%

[blueraven316]

Originally Posted by navin

Try using just the Blau amp but turn the gains down a bit. if the Blau amp is table at 2 ohms it should work.

You can connect 2 different amps to 2 differnet voice coils of the same sub but you will have to carefully match gains so that both amps are pushing the about same watage.

The concept above is correct. The gains have to be adjusted very carefully.
However sir I have one doubt, the amps vary a lot in output, how can optimum balance in power be achieved ? The amps akg7091 is refering to don't support strapping, by which as far as I know multiple amps can power a sub or a combination of subs having on common gain control at the master.
How can we acheive this by using different amps which have different power rating and the output will vary depending on Voltage.

[akg7091]

One more thing navin sir.
I have a normal DMM, not a true rms DMM. Is it okay to use this to set the gains. I will set the gains using a sine wav of 50 hz ( 0db )
I think the normal DMM should be able to show the correct readings as 50 hz is not a very high frequency and they are manufactured to read ac voltages at 50 hz only

[navin]

Originally Posted by blueraven316

The concept above is correct. The gains have to be adjusted very carefully.
However sir I have one doubt, the amps vary a lot in output, how can optimum balance in power be achieved ? The amps akg7091 is refering to don't support strapping, by which as far as I know multiple amps can power a sub or a combination of subs having on common gain control at the master.
How can we acheive this by using different amps which have different power rating and the output will vary depending on Voltage.

I would not suggest strappig either of these amps.

the method suggested earlier is the only way.

I have powered a home DVC sub with 2 mono blocks but in my case the mono blocks were exact copies (concurrent serial numbers from Carver Corp - when Bob was still in charge).

what AKG 701 will have to do is to set the levels so that the sensitivity of both amps is very close. Yes the transfer function of both amps will be slightly different and there will be some back emf due to this but since the amps are both capable of dumping a good ammount of current I dont see this to be a practical issue.

[navin]

Originally Posted by akg7091

I will set the gains using a sine wav of 50 hz ( 0db )
I think the normal DMM should be able to show the correct readings as 50 hz is not a very high frequency and they are manufactured to read ac voltages at 50 hz only

Normally i use 400Hz to set gains. It is a hangover from the days of MOL (tape). But using 50 or 60Hz to set gains for a sub amp should be ok. I would use 60-100Hz to set gains.

[Sam Kapasi]

Originally Posted by panky12345

..but your 306 has a nominal impedance of 400 W RMS only, .

Hi Panky, I'm sure you meant nominal power rating or something. Impedance is only measured in ohms and has little realtion with power rating.

You can have a 10W or 100W speaker, both with a nominal impedance of 4 ohms.

[panky12345]

yes yes my dear yeti! I meant that it has a nominal rating of 400W RMS. Thanks for explaining, too many technical terms you see!! :-)

[akg7091]

ok guys. Will be doing this after 2 weeks.
I will post the results in this thread for others to see