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Author Topic: How to bridge a 2 channel amp for sub ? Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 02-02-2012 09:13 AM                     You high tech guys..........I need this in leigh mans terms, I'm not an electric wiz.......I did a search on the net and got several ways to do this bridging to mono thing, but it is just plain confusing to me...how can you have two + wires going to a sub speaker, what happens to the - post / wire?  |  IP: Logged Robert Minichino Master Film Handler Posts: 350 From: Haskell, NJ, USA Registered: Dec 2005 posted 02-02-2012 09:19 AM                        Push-pull just means there are two active devices on the non-grounded output line, one connected to each voltage rail. A push-pull output stage can be class A, B, or C (or even D, but this is rare). All class B and C amplifiers are push-pull, and most class A amplifiers are as well. A bridged output (also called bridge-tied load or BTL) uses two active outputs to double the voltage swing for the same power supply voltage as compared to a single-ended output, which usually grounds the - terminal.  |  IP: Logged Louis Bornwasser Film God Posts: 4441 From: prospect ky usa Registered: Mar 2005 posted 02-02-2012 10:10 AM                        I am not intimately familiar with thie Smart amp, certainly not in a subwoofer application. Wouldn't any decent amplifier be set up for MONO or MONO BRIDGE operation, just by pushing buttons or dip switches. Like a QSC or Ashly for example? Disregard the negative and connect your sub to the 2 pos. terminals, see above. Louis  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 02-02-2012 10:25 AM                     The original SMART amps did not have bridgeing switchs or push buttons probably that a sub app was the main time that was called for and all of their procesors had a balanced sub output  |  IP: Logged Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 02-02-2012 05:19 PM                     Okay Gordon, I purchased the RDL TX10B Part needed to Bridge the Smart TA425......So I hope you can walk me through the install when it arrives.....I'll let you know when...cost about $38.74 shipped. Thanks for your advice...  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 02-02-2012 06:41 PM                     ..and thx for the info on "Push/Pull" circuitry. I had an idea what it was, but not for sure..why I asked the question. - Monte  |  IP: Logged Oscar Neundorfer Master Film Handler Posts: 275 From: Senoia, GA Registered: May 2000 posted 02-03-2012 11:57 AM                        Gordon said this: "It also is important that on the speaker and booth monitor that there is no connection to ground on the output lines" I will be a little stronger about this. If you intend to use the booth monitor for the sub channel monitoring function, DO NOT do it unless you are 100% sure your monitor has a truly balanced input, is capable of accepting the level generated by the amplifier, and you are 100% sure you know how to properly make the connection. You may end up blowing the monitor, the amp, or both.  |  IP: Logged Paul Vollmers Expert Film Handler Posts: 161 From: Sister Lakes, MI, USA Registered: Jul 2001 posted 02-03-2012 07:27 PM                     Oscar, Thanks for the addional info on using a monitor. I only have it wired for the main speakers. Very good to know.... Stress level going up another notch..!  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 02-04-2012 12:06 PM                     Paul. relax man, it's not that difficult. And I never connect the Sub channel to a booth monitor..think about it for a minute..do you really think a 3"-4" speaker driven by a 5-15 watt amp is even gonna be able to reproduce a sub's signal with enough volume or clarity to tell if there is a problem? Even the QSC DCM series (excellent monitors in many respects) cut out or puke when you try to monitor the sub channel.  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 02-04-2012 04:27 PM                     ...all you really need is the three main ones of L/C/R to monitor.... True, why would one want to monitor sub channel since that just rumbles and grunts to listen to.  |  IP: Logged Jim Cassedy Phenomenal Film Handler Posts: 1661 From: San Francisco, CA Registered: Dec 2006 posted 02-04-2012 06:28 PM                     OOPS! I hit the wrong button!! This needs to be moved to a NEW TOPIC! Sorry! Topic is: "DTS-6D/CP45 Random Mode Switching" I have twice received reports from one auditorum which is using a DTS-6D & CP45 that the "45" has gone into "system insanity", randomly stepping through all the format modes in the middle of a movie. Re-booting the 6D brings everything back to normal. This has apparantly happened twice in the past month, but it's never happened when I've been there, and I am unable to duplicate the problem. Also, I'm getting this info 2nd hand from some booth-monkeys who have limited technical skills. But I'm unaware of anything even a REAL monkey could do that would cause this to happen. The "6D" is running current software and was upgraded to the newer drives about 2 years ago, and I've never had any problems with it. All interfacting between the DTS & CP-45 is through a commercial break-out board using hard-wired connectors, so there's little chance a wire is touching something somewhere in the back of the unit.(But yes, I've checked anyway!) The automation is only capable of pulsing the CP-45 into either Format 4 or non-sync. So I don't beleive it's possible for it to cause the CP-45 to start switching between all modes. If the reports I've gotten are correct, it's happened at least twice since December. >Has anyone else heard of or experienced this problem before?< Also, I know the DTS test disk has a track on it that can make the CP-45 step through all the different format modes. I've run that test & all is working OK. But I'm curious- - does anyonee know how the DTS test track makes the CP-45 do the mode stepping? Is it done through "tones" on the disk? Or is there some machine code on the disk that the DTS recognizes and then outpulses a format change to the processor? Just curious!  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 02-04-2012 11:50 PM                     Simple fix for Jim: cut the body of the new message, and paste this new message in a new window and type your topic title in in the New Topic bar. Then, in this prior message window, simply type "Deleted" in its place and save.  |  IP: Logged

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