How a bout some more FREE power!

Gadget

That's right folks... we have already discussed that we can get 3db of free power just by putting our subs together to take advantage of coupling... Now, Dave Rat has come forth with a way to get up to around 15% more power simply by reversing one channel of the amp input and reversing the output to correct the phase....read all about it here!

http://www.prosoundweb.com/article/figh ... elivered_/

pretty cool stuff!

G

Dr. J

G -- Interesting article. I run my system in stereo as you know...... my subs suck the most power so all I would have to do is switch the amp into \"Bridge Mode\" and leave the speaker cables exactly where they are (In stereo configuration L&R) and then make sure I reverse back the polarity on the output of the side that got flipped either on the cable itself or at the speaker? I assume from the article that it is the \"B\" channel or channel 2 that reverses BECAUSE the switch was put into Bridge mode and finally...... are the subs still technically in stereo? Just want to be clear..... Thanks!

Dennis

No, it won't be stereo. Signal to ch A; engage bridge mode which will parallel ch A input and ch B input while at the same time reversing polarity to ch B input; reverse polarity on ch B speaker cable. You will have mono subs.

Dennis

Dr. J

I see....... Sounds like in Bridge position it is mono both ways -- one where you can take advantage of the more power theory because the reservoir is opposite of the other channel and the other is just plain mono. Since I am a little low on the sub power -- would you suggest just going Bridge? IF so -- Do I need to go back through the wizard and program it for Mono in the DR? Thanks.

Dennis

I am kind of a nervous nelly about bridging at 4 ohms but I don't think Gadget shares my fear. I don't remember which DR you have and don't know if you have to go through the wizard to program \"mono sub\" or can just push the config. button and change that one feature without scrolling through the whole setup.

Dennis

Dr. J

I will look at the config button to do that BUT I will hang back for G's advice. I won't do anything he doesn't recommend. Thanks Dennis.

Gadget

Thanks for the nod but you can take advice from Dennis and Mikey to the bank...they are both OVER qualified for this forum.

As for the amp thing... bridging has benefits and drawbacks... It can offer more power but it will draw more current.. works the amp harder...

Stereo for live sound is not necessary.. I use it because I like the efx in stereo.

The PA and PX do NOT have a config mode per say... you will need to choose a preset, or set one up from scratch in the wizard...

dkrauel

GREAT POST

would there be any benefit to running this set-up a little different if I am running 2 bridged sub amps. run one normal and do the flip flop on the other amp? We use a power tap and have each amp on different breakers, but would it possibly relieve a little current draw?

Dennis

What was described above is more like running in parallel with a twist...no where near the power of bridging. How many subs do you have, how many drivers in each cabinet, what is the impedance of the drivers, and what are you trying to accomplish?

Dennis

dkrauel

2 enclosures w/ 2 x 18\" wired to 4 ohms load
2 amps... 1 per enclosure

enclosures rated 1600watts rms
amps rated 2000watts rms in bridged mode

after thinking about it... I don't think there would be any gain in running 1 amp one way and the other amp back asswards.

Dennis

With your setup, in order to make use of Dave Rat's \"15% more free power\", you would have to split up the 18\" in each cabinet and give each driver it's own input so that amp channel 1 would drive one 18\" and amp channel 2 would drive the 18\" beside it. Now each amp channel is driving an 8 Ohm load. How much power per channel does your amp put out into 8 Ohms? Add 15% to that.

Dennis

mitchiemasha

So, I'm getting from that article that I run my amp in bridge mono mode with both speakers connected to it like normal stereo. Apart from the B channel speaker which I swap the red & black round.

Wont this now mono my system???

All that this bridge mono switch does is reverse polarity to the signal going to the “B� channel

.

He says that but don't amps sum the A/B input too, If both were connected? The volume controls also change on some amps. The B controll becomes ineffective.

I get the theorey but wont it be a lil more complicated with some amps like the crowns using dsp?

Not that I need to do this as I run my 800w 4ohm mach bins off a qsc 3602. Thats enough power for me.

I'm kind of getting a feeling that this would work for a 4 speaker, 2 amp set up. left feed to 1 amp, bridged but wired normal/stereo to 2 speakers, 1 out of phase (but actualy in phase). Then right feed to 1 amp, bridged but wired normal/stereo to 2 speakers, 1 out of phase (but actualy in phase).

Sorry if that makes no sence but I'm trying to get my head round it.

mitchiemasha

yes my first questions are answered above now I'm getting to grips with this idea.