SDA in surround

dongar

I am planning to set up my first HT system and want to use my SDA SRS as front speakers. I have run them in two channel to watch movies and the voices seem to mostly come from the screen.I think they would be fine with out a center speaker.I also think that a sub woofer would not be necessary. The room is 15'x37'the first 15' have a cathedral ceiling that is 8.5' at the sides and 13' at the peak. The height then drops to 7' for the next 22'. The floor is ceramic tile. Wall are drywall the lower ceiling has exposed beams. The speakers are 3' from the side walls 8"from the back wall and 6' apart.I usually sit about 10' away.I would be using a Pioneer Elite VSX-82TXS for power. It is rated for 130 watts into 7 channels at 8 ohms.It is not rated for four ohms but I put it on the 6 ohm setting and let it run for several hours at a very high volume and had no problems with distortion or over heating. However this was just with the two speakers in stereo but at a louder level then I would ever listen to a movie( I was on the next floor). I also have a pair of SDA 1-A at 4 ohms and a pair of CRS at 6 ohms that I could use. I was thinking of using the CRS as back speakers but they would have to be on the wall 24' behind me.So my questions are would this work? or would it be better to have 4 small speakers for the back/sides? should I bi amp the fronts to keep the amp load down (this would mean no sides) How important are the sides? Would I get better sound with 4 SDA speakers then with 2 SDA and 4 small speakers? 4 SDA and 2 small side speakers? Do I need a sub? A center? would the rear SDA's be too far away? Would the SDA effect mess up the surround sound. Would the phase compensation setting mess up the SDA? Any comments or advice would be appreciated. Thanks Don

deronb1

I have never tried using sda in a ht application, other than fronts, but from what i have read here, its not a good idea. Maybe some one can chime in with more specifics

Mr. Bubbles

Some like the SDAs as HT some don't. Though the SRS reach very deep they lack the impact that is ususally desired in HT. In my opinion a sub would be a good addition to them. Think SRT, they have bass cabinets added to the mains. It is my understanding that the SRT originally had SDA rears as well as the mains but later changed to a bi/dipole design for the rear. Not sure why this was. Someone with more experience with the SRT could chime in and maybe add to it. I know the SRT is not the same as the SRS but the basic principals are the same I believe. Again some can correct me if I am mistaken as i have no seen or heard the SRT, just read about them.

Schurkey

dongar wrote: »

I am planning to set up my first HT system and want to use my SDA SRS as front speakers.

Good idea. I like my 1Bs for front-main speaker duty.

dongar wrote: »

I have run them in two channel to watch movies and the voices seem to mostly come from the screen.I think they would be fine with out a center speaker.

Unlikely. I need a center channel speaker, not due to sound placement issues, but so I can turn the dialog volume up enough to make it intelligible. Otherwise the dialog is lost in the special effects.

dongar wrote: »

I also think that a sub woofer would not be necessary.

Not necessary. Perhaps desirable. I don't have a subwoofer with my system, although I did install a Buttkicker.

dongar wrote: »

I would be using a Pioneer Elite VSX-82TXS for power. It is rated for 130 watts into 7 channels at 8 ohms.It is not rated for four ohms but I put it on the 6 ohm setting and let it run for several hours at a very high volume and had no problems with distortion or over heating. However this was just with the two speakers in stereo but at a louder level then I would ever listen to a movie( I was on the next floor).

Marginal. May not damage the equipment, but probably not sonically pristine. You'd do well to obtain proper amplification; suitable for >4 ohm operation.

dongar wrote: »

I also have a pair of SDA 1-A at 4 ohms and a pair of CRS at 6 ohms that I could use. I was thinking of using the CRS as back speakers but they would have to be on the wall 24' behind me.So my questions are would this work?

Not my first choice. Even if your processor allows independent volume control, 24 feet may need a time delay for the other (closer) speakers. Try it and see...

dongar wrote: »

or would it be better to have 4 small speakers for the back/sides?

Home theater can readily use small speakers for the side and rear channels. Multi-channel music is less forgiving.

dongar wrote: »

should I bi amp the fronts to keep the amp load down (this would mean no sides) How important are the sides?

Not a good idea. Side speakers (5.1, or 5.0 if there's no sub-woofer) are important. Rears (7.1, or 7.0 with no subwoofer) are also important, but not as much as the sides. Most of the time, I don't power-up the amp that drives my rear-surround speakers.

dongar wrote: »

Would I get better sound with 4 SDA speakers then with 2 SDA and 4 small speakers? 4 SDA and 2 small side speakers?

I'd just love to try SDA speakers for the rear surround channels. NOT for the side channels.

dongar

Schurkey I have never heard a home theater system but I had no problem hearing dialog with the stereo output through the srs or 1-a speakers. Does the surround sound add more volume to the effects? The receiver has a setting to bring out dialog that I will probably try first if there is a problem. I would prefer not to have the center there is no good place for it in my present (hopefully temporary) setup. I do have an old cerwin vega sub that I used with my CRS speakers when they were the only SDA speakers I had. I think I will try the system without it first because I would rather not have an other speaker in the room. I have been working my way through the manual witch is basically a 90 page list of settings and features with lots of footnotes and references to other sections with no explanation of why or how you would use them.I did find out that the receiver can compensate with delays anywhere from .5' to 45' so the 20' should be no problem. I can also assign the back speakers,witch are actually going to be in the dining room,as a second independently controlled zone. This is why I want to use the CRS speakers there. The processor has a automatic setup that measures all of the volumes and delays and then adjust them . After that is done you can go in and tweak them. It also matches phases and this is where I think there could be a problem with the SDA signal. I suppose I could do the calibration with the interconnect disconnected and then reconnect it.I am not sure if the volume and frequency output are exactly the same in both cases so if there is still a problem the phase compensation can be switched off. Although Pioneer doesn't recommend this. I have 2 sets of small speakers i use to use in my kitchen and garage. One with about a 5" woofer and one with about a 3" would these be sufficient for the sides? I would prefer to use the smaller ones if it doesn't make much of a difference. Thanks Don

westmassguy

dongar, I've experimented with similar arrangements with my Home Theater. My Living Room is much smaller, so my results may or may not apply. I own a similar Pioneer AVR, although mine is a 72TX. My SDA 2ATLs brought it to it's knees very quickly, even with the receiver set for 6 ohm loads. The problem with all AVRs is the limited power supply. Your SRSs are running in 2 channel mode, therefore all power is available to them. I have no doubt your SRSs are using every ounce of the available power from that receiver. As soon as you add more speakers, that finite amount of reserve power must now be distributed between all the connected speakers, and runs out very quickly with multi-channel movie sound tracks. A separate power amp for the SRSs will solve that problem, and allow them to reach their full potential.
I used my CRS+s for surrounds in a 5.1 setup for over a year, and they worked beautifully, however others have not had success using SDAs as surrounds. They must be spaced properly, and setup just as you would if you were using them as fronts, no toe-in, parallel to the back wall. In my case, I mounted them on stands slightly above ear height. The area between them filled in nicely due to the SDA effect, and because of my side walls, the sound wrapped around you. Your room is much larger so I have no clue if your results will be similar.
SDAs do provide a solid phantom center channel, but it's only effective if you happen to be sitting in the sweet spot of the perfect triangle. If you have seating off to the sides like most home theater setups, people seated in those positions will not hear a strong center. I highly recommend a center speaker.
Your SRSs do go very deep, so a subwoofer is not required for 2 channel music reproduction. I turn mine off via the AVR when listening to 2 channel. Home Theater is a different beast however. The LFE or subwoofer channel is specifically designed for low frequency effects, and if blended into the SRSs, it will most likely detract from them. Separate subwoofers are really the best option, since they're designed for frequencies below 80 Hz for THX or 50 Hz which is what I have mine set for.
Regarding the AVR's auto calibration, the Pioneer does a fine job, and any calibration should be done with the IC cables disconnected.
I do find the resulting sound a bit thin however. My AVR can store 6 separate memory settings. I do the auto calibration on the 1st memory setting, and then do my own on the next one. Key information such as speaker compliment, distance and delay are carried over from the auto setup, so I manually set the gain for all channels with my trusty Rat Shack Digital SPL Meter. My own manual settings are the ones I listen to most, and rarely go back to the auto calibration setting.
Just my two cents.

dbleagles

I fought the idea of adding subs to my SDA SRS (I'm original owner--still have the boxes)--but after saving for several years, gave myself my last major audio upgrade couple of weeks ago. A pair of Rhythmik audio G25HP subs. Four 15" drivers w 1800 w per cab and 175 lbs. All I can say is OMG ! The Polks are bi-amped w Marantz 7011and Audyssey has them crossed over at 60 hz and used as "small". Room is 3300 cu ft. To say the sound is solid is an understatement. BB King never sounded so good... (I highly recommend 2 subs!). It is an extravagance in lieu of golf and bass boat etc.

sbb2112

Look at my system in my signature. All the things mentioned by everyone are what I have found to be true. More amp, center channel speaker, sub (I am looking at a better more musical one).

F1nut

dbleagles wrote: »

I fought the idea of adding subs to my SDA SRS (I'm original owner--still have the boxes)--but after saving for several years, gave myself my last major audio upgrade couple of weeks ago. A pair of Rhythmik audio G25HP subs. Four 15" drivers w 1800 w per cab and 175 lbs. All I can say is OMG ! The Polks are bi-amped w Marantz 7011and Audyssey has them crossed over at 60 hz and used as "small". Room is 3300 cu ft. To say the sound is solid is an understatement. BB King never sounded so good... (I highly recommend 2 subs!). It is an extravagance in lieu of golf and bass boat etc.

You cannot bi-amp with an AVR as all those amp channels are sharing the same power supply.

If an AVR is what you've been driving the 4 ohm nominal SRS's with you haven't come close to hearing what they can do.

sbb2112

What he said ^^