Spiky, et al:

I re-read this thread and noticed a comment I'd missed earlier.

Reference "holes" caused by mulitple subwoofers: Am I correct that this only applies when the multiple subs are delivering the same signal?

I'm seriously considering (WAF) using dedicated Sat-Sub combos for each channel - or at least each channel pair, plus a separate LFE sub. With each sub receiving a unique signal, will the "hole" problem still occur?


This message was edited by Bruce Burson on 12/31/01 03:00.23.

Bruce Ol' Bean; In researching for another sub & then for a replacement I came across a rather extensive paper entitled " The placement of one or several subwoofers." By Ingvar Öhman. First published in "Musik och Ljudteknik", no.1, 1997, Sweden.
Way to long to post here.
[Link: sonicdesign.se]
Dougofthenorth

This message was edited by Dougofthenorth on 12/30/01 10:53.27.

Thanks, Doug:

I've read that article before: Although it talks about using multiple subs to eliminate standing waves, I'm pretty sure that was not what Spiky was discussing when he said "There are problems with location of 2 subs, the sound could actually cancel out in certain parts of the room, leaving holes in your room at certain frequencies." Spiky?

Also, it doesn't address my hypothetical situation where each sub is delivering a different signal. The author specifically mentioned he was addressing a situation where all subs carried the same mono signal.

More to follow, I hope! :) Happy New Year to us all!

Bruce/Spiky; I guess the 2 sub issue would tend to cancel out if they were carrying the same signal & placed in such positioning in relationship to each other,the article would then seem to apply.However, should the subs be hooked up split/stereo I think this would favour a better complementation.
As for multiple subs & signals, IMHO I would postulate that there would be 1) some fracturing of the bass injected into the room, & problems with the "steering" of the bass effects. More research then is in order. No?
"Multiple subs can yield smoother in-room response than a single subwoofer. Loading the bass into the room from two or more points can give a better balanced bass throughout the room. However: if the crossover frequency is low, (usually below about 80-90Hz), the best bass will often be with the multiple subs placed next to each other.
-A third sub may be used for the rear surround channels. The Dolby tm. standard calls for a bass roll-off in the rear channels...but "Blockbuster" films often have substantial bass content mixed back into the rear channels. AC3 standards call for more range in the surrounds. Some film lovers feel that having a subwoofer for the rear channel improves impact and realism with such films."
[Link: audioc.com]
[Link: eadcorp.com]

Dougofthenorth

This message was edited by Dougofthenorth on 01/01/02 10:59.30.

Doug,

That's what I'm wondering. I tend to think that multiple full-range speakers (one per channel) don't conflict? If I'm right, whether each channel was a sub-sat combo instead of all drivers in one cabinet shouldn't matter.

Ref your quotation: the rear-channel bass roll off was part of the ProLogicI standard, Dolby Digital allows full-spectrum. They are right about the "blockbuster" movies, too! Since I wired the subwoofer to the surround channels and placed the sub behind my seat, wow. Definitely worth the non-standard configuration, IMHO. :) And since they were talking about 5.1, maybe we need a fourth sub for the rear center? Here we go again...

Hmm...I don't know what to make of that article. Most of the things I've read say that placing 2 subs with the same signal (say, from the LFE channel) in each of the front 2 corners will not do much for your room. I've seen many people with setups where they put both subs in the same corner since that corner is the best place for a sub. Since they are both there, it acts like the article says, reinforcing each other. Doug's last post points this out, too.

I do want to say that for rear channel bass, that's why there are small settings for speakers, to put all the bass in the subwoofer. That's assuming a normal setup where you only have 1 sub. Since bass is almost impossible to localize with our ears below 60-80Hz, one sub does the trick.

There's a guy with an insane setup who is a moderator at avsforum.com with a multiple sub setup. But he also has about $20k into just his Theta preamp, as well. Not exactly the typical room. Here's a link: [Link: digitaltheater.com]

This message was edited by Spiky on 01/02/02 10:02.00.

This guy's my new hero, Spiky. Five subs? I knew I was in trouble when I only recognized two brand names on his equipment list, and both of those WAY out of my price range! I'd love to see it in person, though.

Howdy; I`m trying the Paradigm PW2200 at home this weekend against the YAM YST SW320 - HELP!!-It's trying to shake my house apart!! I had to take stuff off the walls! - I got my first taste of the WAF!! I now know what the boys in U-571 went through- I have now been there with them!! The Yam SW800 should be here in the next few days to test against the PW2200. I came across the Paradigm Reference SW the Servo-15 that has reviewers saying incredible things about it & rate it equal to or better than a lot of heavy hitters out there! Anyone ever listened to it?
Comments?
Dougofthenorth (there go the Ming vases!!)

Hey Doug...
Ive been tossing up to buy the Yamaha YST-SW320 or the Yamaha YST-SW800, Ive listened to them both, i personaly like the 800, but not too sure if its worth the extra money over the 320...
Your opinion on what one you would buy out of those two would be nice.
Also, in the end. what sub do you plan on buying?
And please post back to let me know how the 800 performs in your setup.
Thanks :)
ciao

This message was edited by Cruel^Intentions on 01/07/02 01:26.34.

Cruel; I really like the Yamaha YST-SW320 it is still here along with the Paradigm PW-2200 sub.
I am leaning towards the 320 over the 2200 as the 320 bass is very tight, but the 320 lacks (I think) a very little bit in the music mode(even if the music/movie switch is used), although I admit I left the volume & bass level settings the same.
The Yamaha YST-SW320 lacks NOTHING for movies!
I am probably Cro Magnonish but I will !NOT! start reconfiguring settings from one mode to another! I never had to with the Ken Thx SW & won't with any other either! Short of pushing one easy to reach button.
I find the Paradigm PW-2200 to brutish & "thudy" & even tweeking the sub's settings doesn't solve it.
It responds inappropriately: keys in a scene being thrown on a table create a thud!? In an interview on a TV show the background outside noise drones?! It's like it puts bass where base doesn't belong?
FM radio announcers' voices have a thud thud pud pud? -Not for me & gets the WAF up! For music it's great!
For movies- [after U-571 I think I can qualify for a War Veteran's Pension - I (& my house) got POUNDED!
Collector plates rolled off the wall rails! Pictures tilted! My wife opened the front door & the three dogs vibrated out of the house! Water in the turtle tanks turned to froth & created foaming bubbles-MY GAWD!]
Reviews also only find a little fault with only the 320's MUSIC mode. I have not found 1 review which faults the 800 for anything. I have no WAF with the 320 bye the way! So I figured the 800 should solve my problem. The YST-SW800 will be here anyday.
BUT ...I have also ordered the Paradigm Reference Servo-15 which should be here by Friday.
If I had to choose now:
Between the 320 & the 2200 I would get the 320.
Between the 320 & the 800 I would get the 800 sight unseen & sound unheard.
Between the 800 & the Servo-15 - well I'll know soon enough!!
I will keep you posted re the 800 (& the Servo).
Dougofthenorth (U-571 + 2200= WHEW!!)

The Paradigm Reference Servo-15 arrived yesterday & I tried it out - it's here to stay. Very nice & mellow
where it needs to be. Very natural sounding. Packs an extremely good punch where it has to. it presents the source accurately & does not overstate, or add what is not there. Not "thuddy" at all. I enjoy it for music & HT equally.
I cancelled the Yam SW800 order- sorry cruel.

Dougofthenorth