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Discussion Starter · #1 ·
Hey boys I'm wondering what real world advantage there is with the new recievers offering two sub outputs over the standard one. I curently have the onkyo 876 and use two splitters to feed 3 seperate channels on pro amps to feed 3subs. I like the idea of haveing two seperate outputs for the additional voltage to feed the pro amps and also being one sub is up front it could have a direct connection and the other two are in the back so only one splitter would be required.


So is there enough of advantage to warant a reciever upgrade just takeing in account the extra sub output?
 

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Quote:
Originally Posted by RXPorlando /forum/post/18315971


Hey boys I'm wondering what real world advantage there is with the new recievers offering two sub outputs over the standard one. I curently have the onkyo 876 and use two splitters to feed 3 seperate channels on pro amps to feed 3subs. I like the idea of haveing two seperate outputs for the additional voltage to feed the pro amps and also being one sub is up front it could have a direct connection and the other two are in the back so only one splitter would be required.


So is there enough of advantage to warant a reciever upgrade just takeing in account the extra sub output?

no
 

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Quote:
Originally Posted by jdsmoothie /forum/post/18316181


Generally the lower level AVRs only duplicate the same signal to each sub pre-out and each one is EQ'd the same as well. If that's the case, then no. Some upper level models allow separate EQ'ing so that might be an advantage for you.

Which units have separate EQ for subs? I actually have never heard of this, but I haven't really researched into new AVRs. I always thought Sub Eqs, Eqed for room response so individual subs did not need EQ, but it takes into account for both.
 

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Discussion Starter · #7 ·
So if there is no advantage as far as additional voltage for feeding multible pro amps channels for subs. What's the best way to up the voltage to a solid 2 volts plus per pro amp feed channel? I've heared of a samson product being used but I'm not sure what it was or what it did besides up the voltage to seperate amps.
 

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The Yamaha rx-z11 (list $5499.) has two sub outputs that can be configured as right and left or front and rear. Each has separate settings. The z-11 can be had for a song if there are any left at authorized dealers. Bill
 

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I've been wondering about this, too. I'm curious about the specs being ".2" when I suspect it is really ".1". Am I missing some aspect where they are truly independent channels?


It seems like you would want to do EQ of all the subs operating together, so it doesn't seem like individual EQing of each sub would be useful.


Does the auto-setup set independent phase for each sub? That could be a nice feature.


Do any of the receivers allow you to set independent distances for each sub in the setup? It seems like that might be useful, particularly in cases where one sub is far from the listening position and a second sub is close to the listening position.


A mode that would allow "stereo bass" could be useful in some corner cases where someone actually has their subs located left and right, and maybe is using a higher-than-80 crossover frequency. This kind of setup seems pretty niche, however.


I am really interested to hear specifically what receivers have what features, particularly if the sub outputs are truly independent channels (and not just a y-cable or two electrically independent outputs with exactly the same signal).


As a historical footnote, my Sony STR-DA333ES receiver from the late 90s has dual sub outputs. I suspect the effect is no different than a y-cable. There were no independent settings for each, and I don't even think they were labeled in a differentiated way (e.g. sub1, sub2). That receiver also has a fixed 120Hz crossover frequency, unfortunately.


-Max
 

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The current industry standards (e.g., SMPTE 429M, SMPTE 2036, and their ITU, et al, cognates) seem to make provision for a configuration to contain either a single LFE channel, or an LFE channel pair (typically 'left' and 'right'). But at this time, it seems like the only material mixed with two distinct LFE channels are some experimental/research films. Until that changes, there won't really be a need for real CE agreement on how to handle multiple subwoofers...
 

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Quote:
Originally Posted by aboroth00 /forum/post/18316538


Which units have separate EQ for subs? I actually have never heard of this, but I haven't really researched into new AVRs. I always thought Sub Eqs, Eqed for room response so individual subs did not need EQ, but it takes into account for both.

Harman/Kardon has had dual subwoofer outputs on their AVRs for the last few years. It is part of the HK Room EQ system and each subwoofer is EQed separately and the end-result is a more balanced low frequency response when seated in the listening spot. Harman Corporate including JBL Consumer and Pro R&D teams have been pushing multiple subwoofers for several years. If you google Dr.Toole and/or Dr.Olive you will find some of their technical white papers for this subject..


Just my $0.01..
 

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Quote:
Originally Posted by M Code /forum/post/18324395


Harman/Kardon has had dual subwoofer outputs on their AVRs for the last few years.

I can't find the second Sub Pre-out on my 3550.


The owner's manual also shows one Pre-out for the Sub.
 

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Quote:
Originally Posted by RXPorlando /forum/post/18323473


Do any of the sub EQ's like velodyne etc up the voltage inputs for amps?

Yes. Using an SMS-1 into a QSC pro amp, I do not need a line level shift.


Previously, I had to use an ART Cleanbox (before the rolloff issue was know). The Samson S convert is also commonly used for this.
 

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I sure always loved the concept of dual true L/R subs for stereo 2 ch sources. It seems a dead feature for the most part.




You know as far as LFE is concerned, not as much benefit because after all there is only one .1 or LFE channel from sources.
 

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Quote:
Originally Posted by jehanzeb /forum/post/18371422


I can't find the second Sub Pre-out on my 3550.


The owner's manual also shows one Pre-out for the Sub.

The (2) subwoofer outs were included in their flagship AVRs, starting in 2006 with the AVR745. The 3550 is based on the 354 which are lower cost AVRs use a different processor chip.


Just my $0.01...
 

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Quote:
Originally Posted by JOHNnDENVER /forum/post/18371695


I sure always loved the concept of dual true L/R subs for stereo 2 ch sources. It seems a dead feature for the most part.


You know as far as LFE is concerned, not as much benefit because after all there is only one .1 or LFE channel from sources.

It seems likely (?) that SHV/UHDTV1 will be the next tv broadcast standard [test transmissions starting: Japan in 1015-2017, Europe in 2020+, USA 'whenever']. SHV/UHDTV1 is supposed to include 22.2 channel audio, with the capability to support either a single LFE channel, or an LFE channel pair ("Left" and "Right"). The same 22.2 channel mix will presumably be supported in (derived) material recorded on disk or streamed. But getting content providers to mix two distinct LFE channels, and getting CE AVR manufacturers to do something other than just combining those two LFE channels (into a ".1") after decoding will require more substantial evidence that there is added value to the consumer in ".2" content delivery in a 'typical' home environment...
 

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Thanks for the info Sound Chex... That is encouraging.....


hard to say how much difference it makes, but at leats you wouldnto really have to worry about the subs cancelling each other out by phase differences created by distance differences to any given seating position.
 

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the advantage of two or more seperate sub outs is if you have room correction like audyssey it eq each sub seperate. My Denon AVP A1HD with audyssey Pro looks at each sub differently which it couldn't do with a Y-splitter as it would see the two subs as a single channel.
 
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