my profile | my password | search | faq & rules | forum home

» Film-Tech Forum ARCHIVE   » Operations   » Film Handlers' Forum   » Surround speaker wiring (Page 1)

This topic comprises 3 pages: 1  2  3

Author Topic: Surround speaker wiring Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 01-29-2010 10:10 PM                     What is the best way to wire 3 surrounds on a side wall to bring them to 8 ohms(or 4 ohms)? They are 8 ohms each.  |  IP: Logged Jeremy Weigel Phenomenal Film Handler Posts: 1062 From: Edmond, OK, USA Registered: Mar 2007 posted 01-29-2010 10:35 PM                     What amp are you using?  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 01-29-2010 10:39 PM                     Just wire all three in parallel, if I recall the math correctly it'll work out to around 3.5 ohms...or in any event if you have a modern amp it would handle the load even if it's under 4 ohms. The other, less satisfactory solution is to wire two of them in series, and the third one in series with a 75 watt or higher wirewound 8 ohm resistor. Then wire the two series sets in parallel which will get you 8 ohms.  |  IP: Logged Paul Mayer Oh get out of it Melvin, before it pulls you under! Posts: 3836 From: Albuquerque, NM Registered: Feb 2000 posted 01-29-2010 11:13 PM                        Agreed, definitely parallel if your amp can handle it - with modern amps this should be no problem. Doing series or series/parallel plays havoc with damping and phase issues. Also, if you have enough cable, home run 'em, that is run each speaker's feed back to the rack. Makes it much easier to work on things later on.  |  IP: Logged Tom Wienholt Master Film Handler Posts: 371 From: Towson, MD, USA Registered: Dec 2002 posted 01-30-2010 02:26 AM                     Actually, I believe that wiring the three 8 ohm speakers in parallel would put you at 2.66 ohms.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 01-30-2010 12:08 PM                     Thanks Tom..I was pretty sure it was around 3 ohms, and had for some reason thought it was 6 ohms...I edited my first post. In any event most modern amps, especially for the surrounds, can handle that load, I know the QSC DCA's will.  |  IP: Logged Phil Hill I love my cootie bug Posts: 7595 From: Hollywood, CA USA Registered: Mar 2000 posted 01-30-2010 12:32 PM                  Handy Speaker Impedance Calculator  |  IP: Logged Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 01-30-2010 01:10 PM                     regretably many older ones can't as they have issues delivering that much current  |  IP: Logged Monte L Fullmer Film God Posts: 8367 From: Nampa, Idaho, USA Registered: Nov 2004 posted 01-30-2010 01:45 PM                     ..pretty slick little calculator, Phil .. thx for this link. Couple of years back, I did a single house that just had side surrounds and also with three speakers per side...and I wired them in parallel attached to Peavy 400 amps. Since surrounds isn't going to be doing the large output demand like the front speakers, these amps could handle the usage. -Monte  |  IP: Logged Cameron Glendinning Jedi Master Film Handler Posts: 845 From: West Ryde, Sydney, NSW Australia Registered: Dec 2005 posted 01-30-2010 06:10 PM                     quote: Tom Wienholt Actually, I believe that wiring the three 8 ohm speakers in parallel would put you at 2.66 ohms There are other real world factors, long cable runs and cable type can also increase the ohmage resistance.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 01-30-2010 11:29 PM                     Phil, I also thank you for that link!!  |  IP: Logged Richard May Phenomenal Film Handler Posts: 1057 From: Floral Park, NY USA Registered: Aug 2004 posted 02-01-2010 12:42 PM                     The amp they have will not handle 2 ohms. I may just have to split the surrounds to a third channel on another amp.  |  IP: Logged Sean McKinnon Phenomenal Film Handler Posts: 1712 From: Peabody Massachusetts Registered: Sep 2000 posted 02-01-2010 01:25 PM                        quote: Paul Mayer Doing series or series/parallel plays havoc with damping and phase issues. I was taught to series/paralell to reach a value close to the resistance of the speaker that the amp will tolerate. For example if the surround speakers are 4 ohm's try to come out as close to 4 ohm's as possible. Is this not right, and if so why? ( I know that it will cause some speakers to be slightly louder than others so I always tried to put those at the front of the house)  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 02-01-2010 05:50 PM                       You should try to go for the lowest impedance the amp will feed so 4 Ohms is doable for all good amps except when in bridge mode. Now, the subject of where to place the loudest speaker in your situation is the matter of some debate. Putting it in the front works if you believe it needs to be louder as you are closer to the main channels and of course they are louder as you get closer to the screen. I would tend to put the loudest surround speakers in the last one back or on the back wall at it helps reinforce the idea that the surrounds are coming from the side and back. The patron sitting in the good seats should not get the idea the surrounds are coming from in front of them. This is just me talking here. I hear Steve getting ready to correct me as I write  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-01-2010 08:40 PM                     Not really, I'm in total agreement with you, Sam. I also have been known to put in power resistors (similar wattage to the surround speakers) to ensure an effective match. I also use amps like the QSC DCA-1222...it will safely run in to 1.6-Ohms...so five 8-Ohm speakers can run in parallel. That normally covers all of my situations as I will increase channels after that. Steve  |  IP: Logged

All times are Central (GMT -6:00)

This topic comprises 3 pages: 1  2  3

Printer-friendly view of this topic

Hop To: Select a Forum: Category: Operations -------------------- Digital Cinema Forum Film Handlers' Forum Large Format Forum Ground Level Feature Info, Trailer Attachments & REAL Credit Offsets Category: Community -------------------- Film-Yak Film Handlers' Movie Reviews The Afterlife Bob Maar's Joke-A-Thon Category: Classified -------------------- Equipment and Supplies Wanted/For Sale Help Wanted/Seeking Employment Category: System -------------------- Software Beta Testing Forum

The Film-Tech Forums are designed for various members related to the cinema industry to express their opinions, viewpoints and testimonials on various products, services and events based upon speculation, personal knowledge and factual information through use, therefore all views represented here allow no liability upon the publishers of this web site and the owners of said views assume no liability for any ill will resulting from these postings. The posts made here are for educational as well as entertainment purposes and as such anyone viewing this portion of the website must accept these views as statements of the author of that opinion and agrees to release the authors from any and all liability.