Adding a Subwoofer to a SDA SRS2 Home Theater

Joe08867

When H9 said mish mosh I think he was talking about the Timbre Match of the speakers. You have many different Tweeters and Drivers all trying to work together. That doesn't usually mix as well as timbre matched tweeters and drivers. The Center and the SDA's aren't what I would do but if it sounds good to you then you are all good.

Does your system sound bad? I don't know, You enjoy it and that is what matters.

I think adding subs could be good if you tune them the way DK mentioned. Using them for ultra low and to take the stress off the mains.

mustgtguy

I understood the timbre match thing way before I added the speakers to the SDA's.
Fact of the matter is, if you use older speakers for a home theater you CAN'T truly timbre match them.
Me adding the CSi5 and FXiA6's were at the suggestion of Polk Audio when I called them. They said the would be very closely matched and would work well...they were right!

evhudsons

DarqueKnight wrote: »

One thing to consider is that stereo loudspeakers designed for music are not the best for reproducing the low frequency sound effects from movie sound tracks. You don't want to abuse a nice pair of stereo speakers in this way. The SRS 2's 15" passive radiators were meant for reproducing the low frequencies commonly found in music.

For home theater applications, I would strongly recommend a large good quality subwoofer to handle the very low bass frequencies from movie sound tracks. Routing the very low frequency sounds to the sub will allow the front, center and surround speakers to play more cleanly and accurately.

I want to point out that after installing the subwoofer and getting it calibrated properly, it may sound like you actually hear less bass. What you will be hearing is actually more cleanly defined and articulate bass without the previous bass distortions caused by the smaller speakers trying to reproduce very low bass frequencies. If you pay close attention, you will be feeling more bass against your body and seat rather than hearing louder bass. It takes some people a while to get used to this more accurate low bass representation.

If your home theater system also doubles for music listening duty, then I would say the use of a subwoofer with the SRS 2's is a matter of taste. I have SDA SRS's as front speakers in my home theater system. When listening to music on this system, most of the time I don't use the subwoofer, but sometimes I do if I'm in the mood for a little extra bass kick.

I fully agree with the DarqueKnight, you need the clean low bass that only comes out when needed. In my system, I have on receiver my crs and two side surrounds. Then another receiver just for the sub. I bought mine from an auto sound shop, two 15inch subs in a plexiglassed front sealed but ported on the side band pass box carpeted for trunks. It was huge. I used in my 1974 VW camper van. I used the box as a seat as the stock seats had been removed. I pulled it out and used the 4 ohm speakers hooked to my home receiver, and it puts out just the right amount of bass. I am using the single subout rca jack to the subreceiver, and wires to the sub. Most of the time you really don't hear bass, only from the CRS which does have some clean bass just not theater shaking. With my setup, I think what you are looking for is for those particular moments you physically feel the bass in your bones, some things rattle, and you feel the air pushed around you. My small CRS is not over extended, and everything feels very natural. I don't, and I repeat don't ever turn up a bass knob or selection anywhere in the system. Nope.

I constantly change the volume on my sub receiver, depending on the source and intent of what I want. It gives you choices. I would say it is just the same advice of having more power, gives you cleaner sound so you don't have to turn it up as much. My subs subsonically boom, they don't thud or bump. If you want that, go get a ghetto blaster and overdrive it full volume on some half melted tape and stick your ear right in there.

Here's a picture of my sub after I coated it in wood to blend in. My cat and time and parties took it's toll, and although not pretty, it blends in much better. You can't tell where it is coming from. It can shake the whole house, make the neighbors bring their lawn furniture in, and scare the dogs.

http://www.flickr.com/photos/65915807@N05/6003771184/sizes/l/in/photostream/


http://www.flickr.com/photos/65915807@N05/6003207287/sizes/l/in/photostream/

http://www.flickr.com/photos/65915807@N05/6003216363/sizes/l/in/photostream/

http://www.flickr.com/photos/65915807@N05/6003769266/sizes/l/in/photostream/

http://www.flickr.com/photos/65915807@N05/6003771184/sizes/l/in/photostream/

I'm not sure how to post pictures yet, I tried didn't work. Hope I'm not breaking rules. But you can see that placement can be anywhere, and it doesn't have to be as big as that, or as ugly as it once was. It fills the entire house with the purest sweetest clean properly raised with etiquette bass.

Look around, there are always some broke bassheads getting rid of their boxes and subs, and then you can hook them up to your system, but I found that having a separate receiver is the way to go. You can get really good powerful ones cheap because you don't need any features really, just the amp.

And keep the bass as low as possible, turn it up at a point where there would be a low rumble, and keep it there. you'll be surprised at how much powerful it sounds when you sit back at a lower level than if you had it too high thumping like certain folks riding around town setting car alarms off.

I hope you have a single family home.

evhudsons

I just reread some of the earlier posts about 11 channels. Maybe the guy has a converted church or something.

I tried to do the 7.1, but found it better with SDA to remove the center channel, just have two small surrounds carefully placed to the side, my sub, and that is it. I did away with the center, and surround backs. They interfered. With normal speakers I suppose they add but for my CRS+ it kills the SDA if not set up right. I also emphazise proper placement of the sda speakers. I use a measuring tape and a cross measure to make sure they are in perfect alignment. It is crucial. Eyeballing that wasn't too successful for me. I also think it gives more power to the right speakers if you have less speakers.
I hate distortion and underpowered over driven speakers.

Joe08867

mustgtguy wrote: »

I understood the timbre match thing way before I added the speakers to the SDA's.
Fact of the matter is, if you use older speakers for a home theater you CAN'T truly timbre match them.
Me adding the CSi5 and FXiA6's were at the suggestion of Polk Audio when I called them. They said the would be very closely matched and would work well...they were right!

I also thought you had Mirage Speakers since you only put Model numbers in your first system post. I had forgotten you said you had all Polk speakers.

And I am sorry you can Timbre match them just not with the Current lineup from Polk. Not sure why I am explaining since you seem to have all the answers you want and haven't even commented on the suggestions anyone has put forth so far. Good luck.

Crashdot

From what I understand, theatrical audio is designed for use with subwoofer(s). With such a fine home theater, there is no good reason not to add a sub, but I would recommend adding two for best results.

Acoustically, a single sub is not supposed to be as good as 2 or 4 subs, which will provide better and more even bass response. For example, I have a terrible 45hz peak in my listening position due to standing waves. I tried many things to resolve this, including spending a lot of money on bass traps and many hours trying to use equalization or changes in speaker placement to overcome the problem.

Eventually, with the help of Nyal Mellor at Acousticfrontiers.com, I was able to pinpoint the exact problem, and even find a working solution. I needed to add a second identical sub on the opposite wall from the first one. The bass peak disappeared due to cancelation of the frequency that was being doubled, leaving only clean and satisfying bass that is appropriate to the recording. There are some articles that help explain the phenomena:

http://forum.blu-ray.com/subwoofers/48286-guide-subwoofers-part-ii-standing-waves-room-modes.html

http://www.harman.com/EN-US/OurCompany/Technologyleadership/Documents/White%20Papers/multsubs.pdf

I'm not sure that a single sub would sound much different, aside from a reduction in intermodulation distortion, since you have large speakers - but two subs may produce the significant improvement you may be looking for.

Cheers

mdaudioguy

^^ Yes, but he doesn't seem to be interested in "theatrical" audio. His interests appear to be concert DVDs, not movies with booming LFE tracks. Musically speaking, he's probably got the full range covered.

Crashdot

Dual subwoofers seem to provide much smoother bass than speakers alone, whether listening to stereo or multichannel music. Highly recommended.

OldmanSRS

I run a VTF-3 sub with my 1.2's crossed at 25 Hz and at a very low volume. It adds the explosive effects for HT and the very lowest bass for music. The sub is between the front speakers. I've moved it around the room and settled on the curent placement for smoothest response.

The room has standing waves. The sweet spot is in a null at 30 hz with the 1.2s. I have expiremented with running the sub in and out of phase with the Polks and each mode produces less than perfect results. Such is the case when running a sub with full range speakers. Out of phase produces the best 18-30 hz boost but at the expense of 30-50 hz.

evhudsons

wow, great info!

How do you guys check for the hertz levels?

Nice Mustang by the way odmansrs, I have 1990 gt convertible 5.0 manual. My wife wants me to get rid of it, but I hate to part with quality.

OldmanSRS

I use some recorded test tones and a variable frequency tone generator. I have a SPL meter but ears can tell a lot without the need to see the actual dB measurements.

Thanks for that about the car. It's not a Mustang though... :biggrin:

intangible

Room correction might be able to help with your room modes. The bass response in my room had giant 20db variances, but an afternoon of playing with REW left things as flat as one could hope up to 100Hz.

evhudsons

I think I will lower my crossing level to see how that responds. I like the lower bass but only when needed. You are right about the ears, but I'm not educated on what to be listening for and what level the hertz would or should be.

and, oops, that most certainly is not a Mustang! Sweet ride, indeed, and very rare.