Stereo subs - Do they rock or is it overkill?

[Enoch]

Originally Posted by Westcoaster

I have done this for years...

If you have a receiver that has 'pre-out' and 'main-in' you can use and electronic crossover to get the bass to a set of stereo subs.

See my recent post here: http://www.avrevforum.com/subwoofers...er-2-subs.html

you could run speaker level to the sub on it's way to the mains (or rears in my case) Two subs: one for the front two and one for the rear two. This helps with my multi-channel audio listening. Most subs still have speaker level inputs, don't they?

[Mitchell Erblich]

Ooops,, DID I had stereo subs years ago?

My vintage modified Infinity IRSs Betas currently reach down to 10Hz which hopefully are stereo or are they quad
(2 mid/tweeter panels and two sub towers) . So, the biggest question do full range speakers require one or two or no sub(s)?

If a sub has a high xover freq and/or a slow rollover, won't it be producing directional freqs? Speakers in general
produce a loudness based on the size of the drivers and power. With a sub these power demands are extremely high.
So, with a room of say 100 sq ft, probably doesn't need 2 subs if it isn't producing directional freqs. However, my
Beta subs are directional and are for rooms close to 1000 sq ft or larger...

Some hi-end companies are adding up to 4 channels of sub support in their processors. Do you really need
that with FULL range speakers? Did they assume you have sats?

IMO, some movies are producing freqs that are specific for subs, so you
will be missing SOMETHING. BUT IMO, a center is the more important 2nd step, then rears if your fronts are
full range, then add subs...

Well, I am currently PLAYING with 8.4, yes 4 channels of independent sub channels with 8 full range
(ah, my center ML Logos doesn't go that low) so minus 1, 7 channels. But no, I think Yamaha is coming
up with 11 main channels.. Where will this stop??? Go to your IMAX theatre, maybe a home IMAX.

[blownrx7]

Originally Posted by Brian

I have found that they work better in my room than a single subwoofer. The room nodes are minimized and each subwoofer is required to work less.

I also have two subs
They are in non-ideal positions but, oddly enough, I needed minimal room correction. I wonder if this node cancellation thing is the reason.

[hifidr]

I have been reading articles on this subject for years. Most are based on perfectly legitimate theoretical considerations. However, a simple experiment (which I have repeated many times with different systems and rooms) will solve the question for those willing and able to perform such an experiment.

Wire up a system this way and follow these instructions:
1. Preamp main outs to power amp to stereo speakers with limited or declining bass output below ~40 Hz.
2. Secondary preamp outs (or split main preamp output) to preamp with remote controlled mono/stereo switch (I used an old Adcom). Set preamp volume to unity gain.
3. Preamp outputs from secondary preamp to stereo subs. Set sub volume controls with 35 HZ Hz test tone and Radio Shack SPL meter to equal volume of primary speakers at 40 Hz (This is not too critical and can be done by ear using a recording of a musical instrument spanning these frequencies.)
4. Position subwoofers symmetrically to the outside of and at a slightly different toe-in angle to main speakers.
5. Listen to any familiar well-recorded CD in your normal listening position and switch between stereo and mono on the secondary preamp.

The actual frequencies necessary for producing the large improvement in sound which you will hear have experimentally been determined to lie below 25 Hz. I won't bother to describe the exact nature of the sonic benefit that follows from this setup nor will I engage in theoretical arguments such as those put forth in the Harmon white paper. Do this experiment and you will be convinced. Once you have done this, you will never consider using single or dual mono subs ever again. Every high end system should be set up this way.

[rickcreel]

In designing commercial and residential theaters, we use multiple subs. The thing to remember is that subs are non-directional. The idea is not to get "stereo" sound from the subs. Really, all you want is yoiur crossover to send the lower frequencies to the subs. The purpose of two is so you don't have to crank one all the way out and thus they both work easier. As for sound quality, the larger the speaker (18" comapare to 12'), the better the sound. Also, the more "throw" the sub has, the more air that it moves. This is what gives you feel. Time alignment with your other speakers (if your sstem allows that) is what will assist you in getting clearer sounds over muddy ones.

You can visit our site at www.advancedaudiovideo.com for more information on designing a room for sound and placement of speakers. I hope this information helps.

[rlpiii]

Originally Posted by rickcreel

In designing commercial and residential theaters, we use multiple subs. The thing to remember is that subs are non-directional. The idea is not to get "stereo" sound from the subs. Really, all you want is yoiur crossover to send the lower frequencies to the subs. The purpose of two is so you don't have to crank one all the way out and thus they both work easier. As for sound quality, the larger the speaker (18" comapare to 12'), the better the sound. Also, the more "throw" the sub has, the more air that it moves. This is what gives you feel. Time alignment with your other speakers (if your sstem allows that) is what will assist you in getting clearer sounds over muddy ones.

You can visit our site at www.advancedaudiovideo.com for more information on designing a room for sound and placement of speakers. I hope this information helps.

Never heard of this before (from your web site): http://www.advancedaudiovideo.com/ho...erroomsize.htm

POINT 2 - Dimensions

If your room is 12W X 16'L X 8'H, notice that all of these dimensions share a common denominator of 4. This goes back to the same audio anomaly's mentioned in the previous point. However, you can change these figures by just 1 foot and eliminate many of these problems. You would also eliminate the "common denominator" factor.

Also noticed you sell BOSE! HA HA