Prev: RF, Audio? I can't tell the difference any more.
Next: efficient PA system and great mic technique
From: Tone E on 10 Jul 2008 08:25
Hi All

I'm seeking advice (and probably the logic why) on how best to run the
following system.
The setup : 1 x QSC PLX3402 and 8 single 8 ohm 15" subs.

Is it best to:

A: run 4 boxes either side, that is as rated 1.7kw into a 2 ohm load per
side

or

B: bridge the amps output and run 3.4kw as rated into 8 boxes patched up to
present a 4 ohm load to the amp.

The subs are crossed at 110hz. Running in stereo is not a priority at this
venue.


Many Thanks

Tony






From: George's ProSound Company on 10 Jul 2008 08:34

"Tone E" <tonymika(a)bigpond.com> wrote in message
news:ldndk.18635$IK1.4663(a)news-server.bigpond.net.au...
> Hi All
>
> I'm seeking advice (and probably the logic why) on how best to run the
> following system.
> The setup : 1 x QSC PLX3402 and 8 single 8 ohm 15" subs.
>
> Is it best to:
>
> A: run 4 boxes either side, that is as rated 1.7kw into a 2 ohm load per
> side
>
> or
>
> B: bridge the amps output and run 3.4kw as rated into 8 boxes patched up
> to present a 4 ohm load to the amp.
>
> The subs are crossed at 110hz. Running in stereo is not a priority at this
> venue.
>
>
> Many Thanks
>
> Tony

either way your not getting the sound you paid for out of the amp
the bass will be soft and mushy
get a additional amp and run two speakers per channel
george
>
>
>
>
>
>


From: Eeyore on 10 Jul 2008 09:07


George's ProSound Company wrote:

> "Tone E" <tonymika(a)bigpond.com> wrote in message
> >
> > I'm seeking advice (and probably the logic why) on how best to run the
> > following system.
> > The setup : 1 x QSC PLX3402 and 8 single 8 ohm 15" subs.
> >
> > Is it best to:
> >
> > A: run 4 boxes either side, that is as rated 1.7kw into a 2 ohm load per
> > side
> >
> > or
> >
> > B: bridge the amps output and run 3.4kw as rated into 8 boxes patched up
> > to present a 4 ohm load to the amp.

Frankly it makes no odds except the patching will be a PITA.


> > The subs are crossed at 110hz. Running in stereo is not a priority at this
> > venue.
>
> either way your not getting the sound you paid for out of the amp
> the bass will be soft and mushy
> get a additional amp and run two speakers per channel

Agreed.

Graham (never run 2 ohms/ch or 4 ohms bridged except in emergencies)

From: J Wald on 10 Jul 2008 18:19


"Eeyore" <rabbitsfriendsandrelations(a)hotmail.com> wrote in message
news:4876099B.E49291CD(a)hotmail.com...
>

>
> Agreed.
>
> Graham (never run 2 ohms/ch or 4 ohms bridged except in emergencies)

My plan is/was to run 4, 8 ohm 600/1200/2400watt Peavey SP118 subs with 2
QSC 2450's. Bridged, they provide 2400 into 4ohms which would be 1200 to
each cab. Correct?
Thanks.
--
J Wald

Tattaglia's a pimp
Vito Corleone - Godfather I

>


From: liquidator on 10 Jul 2008 20:36

"J Wald" <wldj4(a)grics.net> wrote in message
news:g561v6020m1(a)enews2.newsguy.com...
>
>
> "Eeyore" <rabbitsfriendsandrelations(a)hotmail.com> wrote in message
> news:4876099B.E49291CD(a)hotmail.com...
> >
>
> >
> > Agreed.
> >
> > Graham (never run 2 ohms/ch or 4 ohms bridged except in emergencies)
>
> My plan is/was to run 4, 8 ohm 600/1200/2400watt Peavey SP118 subs with 2
> QSC 2450's. Bridged, they provide 2400 into 4ohms which would be 1200 to
> each cab. Correct?
> Thanks.
> --
> J Wald
>

You are somewhat being blinded by science.

While what you post is true, the amp will only put out 1200 watts mid band.
Take a look at the ratings- you'll note the 8 and 4 ohm per channel readings
are full range, lows to highs, while the 2 ohm and 4 ohm bridged (basically
the same to the amp) are at 1 khz only. This allows them to say the power is
higher than it really is.

And since you are using these at LF not at 1 kHz, they won't put out that
much power.

If you haven't bought subs yet, seek 4 ohm units and give each it's own
channel. Even if you have, I would still give each it's own channel.

Bridging is championed a lot by unknowledgeable people. While there is a
time and place for it, many times it's a bad idea.


 |  Next  |  Last
Pages: 1 2 3 4 5 6 7
Prev: RF, Audio? I can't tell the difference any more.
Next: efficient PA system and great mic technique