Speakerplans.com Homepage
Forum Home Forum Home > General > Amp Forum
  New Posts New Posts RSS Feed - Running an amp in parallell mode
  FAQ FAQ  Forum Search   Events   Register Register  Login Login

Running an amp in parallell mode

 Post Reply Post Reply
Author
Message
goodgroove View Drop Down
Young Croc
Young Croc


Joined: 21 December 2005
Status: Offline
Points: 541
Post Options Post Options   Thanks (0) Thanks(0)   Quote goodgroove Quote  Post ReplyReply Direct Link To This Post Topic: Running an amp in parallell mode
    Posted: 15 March 2012 at 9:05pm
Hi hoping to understand this correctly but if I have an amp that is 1200wpc into 4ohms running stereo thats a total of  2400w giving 600w per speaker , this amp into 4 ohm bridged mode will give 3200w into 2 8ohm speakers  but in parallell mode it will be 4 speakers going down to a 2ohm load getting 3200w  with each speaker getting 800w is this correct ? 
Back to Top
ceharden View Drop Down
Old Croc
Old Croc
Avatar

Joined: 05 June 2005
Location: Southampton
Status: Offline
Points: 9898
Post Options Post Options   Thanks (0) Thanks(0)   Quote ceharden Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2012 at 1:28am
Running in parallel mode will give you the same power into 4 speakers as running in stereo, there's no advantage that I can see.  Although the total load will be 2Ohms, each amp channel will see 4Ohms.  Just as running in bridge mode into 4Ohms, the amp channels will see 2Ohms each.
Back to Top
Dub Specialist View Drop Down
Old Croc
Old Croc
Avatar

Joined: 30 December 2011
Location: Smethwick
Status: Offline
Points: 3233
Post Options Post Options   Thanks (0) Thanks(0)   Quote Dub Specialist Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2012 at 1:42am
to be honest ive never really understood parallell mono i have a number of amps some crown ect that have parallell mono mode what exactly is the difference?
 
theres got to be a difference b'cus why is the mode there? can some pro on here explain please...
 
thanks...Thumbs Up
Back to Top
levyte357 View Drop Down
The 10,000 Points Club
The 10,000 Points Club
Avatar

Joined: 10 May 2004
Location: UK, London
Status: Offline
Points: 11733
Post Options Post Options   Thanks (0) Thanks(0)   Quote levyte357 Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2012 at 1:46am
Switching amp into parallel mode just routes signal input to channel1 to be input to channel 2.

E.g, you want the same signal amplified thru both channels.

As ceharden already said, it's just the same as using in stereo.
"Who am I? I'm the guy who does his job.. You must be the other guy".
Back to Top
Dub Specialist View Drop Down
Old Croc
Old Croc
Avatar

Joined: 30 December 2011
Location: Smethwick
Status: Offline
Points: 3233
Post Options Post Options   Thanks (0) Thanks(0)   Quote Dub Specialist Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2012 at 1:57am
Originally posted by levyte357 levyte357 wrote:

Switching amp into parallel mode just routes signal input to channel1 to be input to channel 2.

E.g, you want the same signal amplified thru both channels.

As ceharden already said, it's just the same as using in stereo.
 
nice one lev nice n simple explantion ...cool...
 
i tell ya tho if i was the copy n paste of the internet it would mek ya laugh.sooo many different answers man....
Back to Top
cravings View Drop Down
Old Croc
Old Croc
Avatar

Joined: 30 January 2007
Location: Ireland
Status: Online
Points: 5029
Post Options Post Options   Thanks (0) Thanks(0)   Quote cravings Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2012 at 2:00am
paralell often means that channel a and b will both reproduce the signal going into channel.. so it's basically a mono amp, but still 2 separate channels. the output figures would be the same as you originally said above (2 x 1200 @ 4 ohm)

edit: lev said it better.. i'm leaving piles of tabs open for too long obviously

Edited by cravings - 16 March 2012 at 2:01am
Back to Top
Chris Murphy View Drop Down
Registered User
Registered User


Joined: 23 December 2011
Location: Walsall
Status: Offline
Points: 28
Post Options Post Options   Thanks (0) Thanks(0)   Quote Chris Murphy Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2012 at 2:20am
Theres a bit of a difference between parallel inputs and parallel mode, especially with crown. Macrotechs require you to install a wire between positive output terminals and run all speakers from channel one, inputing channel one. Compare that to a qsc which does literally just link the input channels when in parallel so that you dont have to input it twice or link it with a cable externally if you want both channels feeding with the same signal. I guess its sort of another type of bridge mode with certain amps, only difference you can drive a 1ohm load.

Quote from crown manual Smile

3.3.3 Parallel-Mono Operation
Parallel-Mono mode is intended for driving loads with a total impedance of less than 4 ohms (see Section 3.3.2 if the load is 4 ohms or greater). Installing the amplifier in Parallel-Mono mode is different from the other modes and requires special attention.

To activate Parallel-Mono mode, turn off the amplifier, wait at least 10 seconds, and slide the stereo/mono switch to the PARALLEL MONO position. Connect the
input signal to Channel 1, and do not use the Channel 2 input. Both outputs will now receive the signal from the Channel 1 input.
Note: The Channel 2 input jack and level control are disconnected in Parallel-Mono mode. A signal feeding Channel 2 will have no effect on the output.
Install a jumper wire between the positive (+) outputs of Channel 1 and 2 that is at least 14 gauge in size. Then, connect the load to the output of Channel 1 as shown in Figure 3.6. The positive (+) lead from the load connects to the positive (+) Channel 1 terminal, and the negative (–) lead from the load connects to the negative (–) Channel 1 terminal.

http://www.crownaudio.com/pdf/legacy/103169.pdf

Quote from Qsc manual :)


Parallel Mode - This setting connects both inputs together. One signal feeds both channels. Each channel's Gain control and loudspeaker connection remain independent.

http://www.qscaudio.com/pdfs/manuals/RMX_3RU_user_manual_EN_revF.pdf


Edited by Chris Murphy - 16 March 2012 at 2:28am
I consider myself an intermediate rather than an expert :)
Back to Top
knet94 View Drop Down
Young Croc
Young Croc
Avatar

Joined: 31 March 2008
Location: NW London
Status: Offline
Points: 1072
Post Options Post Options   Thanks (0) Thanks(0)   Quote knet94 Quote  Post ReplyReply Direct Link To This Post Posted: 16 March 2012 at 3:39am
Come on Spanners tell us what the advantages are.
Back to Top
kedwardsleisure View Drop Down
Old Croc
Old Croc
Avatar

Joined: 20 January 2009
Location: Staffordshire
Status: Offline
Points: 3021
Post Options Post Options   Thanks (0) Thanks(0)   Quote kedwardsleisure Quote  Post ReplyReply Direct Link To This Post Posted: 18 March 2012 at 10:18pm
Certain RCF/DB Tech amps also use internal relays to parallel the output channels in parallel mode, though it's not the norm.

Some amps in parallel mode are just like the crowns in that you can parallel the output terminals to drive very low impedance loads; however this means the circuitry in the amps is carefully matched between channels and shouldn't be done willy-nilly unless the manual says so.
K. Edwards Electronics Engineers

North Staffordshire

Back to Top
GEB View Drop Down
Old Croc
Old Croc


Joined: 13 November 2009
Location: Head in speaker
Status: Offline
Points: 1564
Post Options Post Options   Thanks (0) Thanks(0)   Quote GEB Quote  Post ReplyReply Direct Link To This Post Posted: 19 March 2012 at 9:21am
Comes in handy when you've misplaced one of your xlr link cables when setting up for a gig!
Back to Top
Norseman View Drop Down
Registered User
Registered User


Joined: 04 March 2013
Location: Bendigo
Status: Offline
Points: 34
Post Options Post Options   Thanks (0) Thanks(0)   Quote Norseman Quote  Post ReplyReply Direct Link To This Post Posted: 09 September 2013 at 9:36am
yeah it appears to be good for subs etc in mono, coming from LMS use one output for two bins etc, rather than chewing up two LMS outputs for two bins...
Back to Top
 Post Reply Post Reply
  Share Topic   

Forum Jump Forum Permissions View Drop Down



This page was generated in 0.344 seconds.