Does anyone have first hand experience with setting up multi-speaker per channel for Surrounds?
I am setting up 7.1 +Presence in a 13’x 22’room using for SPKR SYSTEM A 3x Jensen EHT-8 130W 6 ohm in walls for front stage + 2 EHT-6 110w 6 ohm for Presence speakers (Yamaha RX-V2600 AVR), 2 home made subs, and 2 EHT-4 110w x 6 ohm 40 degree- angled drivers in wall or ceiling (not yet sure) for REAR surrounds. (SYSTEM B: is my old pair of 5spkr x 4way Sansui SP1500 for stereo listening).
Here’s the 7.1 problem area – I have 3 rows of seating so I have been trying to emulate the “multiple side” speakers in commercial theaters so that every row has the correct positioned (side) surrounds (i.e. before I came to know that comm Theatres us 10.2 and have all active (amplified) speakers). So I am trying to place 3 pairs of Surrounds along each side wall at 90 -110 degrees to each row. So do I wire –
• 3x PARALLEL, or
• 3 x SERIES, or
• 2x SERIES + 1 x PARALLEL, or
• 2 x PARALLEL + 1 x SERIES, or
• Use an Impedance Compensation device of some sort (and what should/does that present as an impedance value to the surround channels of the AVR?)
See I don’t want to cause EQ issues for the YPAO system, or degrade sound quality, or affect the “relative” volumes of SL and SR compared to the other channels for the listeners in each of the rows.
Thoughts thus far: My first thought was to maintain 6 ohm load/surround-channel to be seen by the AVR so I don’t introduce quality/balance or danger problems to the AVR. To do this I can’t just wire as 3in Para = 2 ohm, 3 in Ser =18ohm, 2 Para + 1 Ser = 9 ohm, and 2 Ser + 1 Para = 9 ohm (Right???). So I’ve hunted for a “black box” only end up buying on recommendation (?) a no-brand one (1pr -> 4 pr) from Radio Shack/Tandy that was supposed to use combinations of series and parallel (?????) to maintain the impedance seen by the AVR at the same value as “the lowest impedance speaker in the array”. BUT it does not do that. I hooked them up and made measurements –
• 2 SPEAKERS-
o Switch 1 +2 = 6 -> 12ohm (obviously just series);
o Switch 3+4 = same (series);
o either (1 or 2) + either (3 or 4) = <3ohm (seems like just parallel); and
• 3 SPEAKERS –
o any pair of 1 + 2, or 3 +4 with ONE of the other two = 4ohm (not sure why ?????).
• 4 SPEAKERS`-
o of course as 4 speakers it gave the original 6 ohm as the be expected by 2 parallel pairs then each air in series with the other parallel pair. But if I use 4 (side) surround speakers per channel the only space for placement of the 4th pair will be FORWARD of Row 1 and then cause as shift of the surrounds track well FORWARD for each Row. Not to mention the price of another pair of speakers - money thrown away.
o
I have seen webpages with products like Phoenix SAM100 and DAYTON SSC-5 SPEAKER SWITCHING CENTER but none of the sites gives specific information as to what methods are used or what impedance values you can expect with various number of speakers (and no “contact us“ links obvious).
Key Discussion Point: I am now starting to question the merits trying to show the AVR 6 ohm just to match the other channels. The first audio-shop guy said “hook the three up in series (18ohm???) so that even though the volume of each will be lower , the SUM of the output from the 3 speaker array will be the same as the intended original for ONE SPEAKER (I’m not even sure that is right??).
I argued that may(?) be mathematically correct but (a) most of the volume “heard” in any row would be from the near (90-110 degree adjacent speaker and much less from the other two more “distant” speakers, and (b) the reduced volume levels surely would also drop the quality based on the dynamics of the speaker (sensitivity rating etc??). A second audio-shop guy told me “then just hook them up all in parallel: that way each speaker will output the intended volume level as though it were the only one alone. (Yes but what about risk to the AVR at ~ 2 ohm, and its “confusion”, and what do it set in the menu to for spkr impedance where 5 channels are 6 ohm and 2 are 2 ohm?)
So in conclusion I’m more uncertain that ever. Do any of you guys or gals have first hand experience/knowledge as to what is the bets way for me to proceed from here and get it “right” first time? REMEMBER please that with in-wall, in-ceilings I don’t have the luxury or placing them in multiple locations with multiple hookups to repeated test out all the iterations UNLESS I WANT SWISS CHEESE for my final walls and ceilings
Phantomguy
Brisbane. Australia.
P.S. Sorry for long post but after weeks of getting nowhere I’m now highly frustrated.
