[mlundy57]

I’m trying to understand the differences between three types of speaker setups :

(1) a pair of full range towers (20Hz – 20kHz)
(2) a pair of stand mounted monitors plus a pair of subwoofers (one for each channel) and
(3) a pair of stand mounted monitors with the low frequencies summed into a single subwoofer.

Use these systems for comparison:

(1)   A pair of full range speakers:  N3-S's on top plus servo woofers on the bottom
(2)   Stand mounted bookshelf speakers with a separate sub for each channel: a pair of N3-S’s on stands + 2 servo subs, one for each channel but not necessarily positioned directly under the N3-S’s
(3)    Stand mounter bookshelf speakers (N3-S’s) plus a single servo sub with the low frequencies for both the left and right channel summed.

What would be the differences, the pros and the cons of these three setups? Thanks.

Mike

[AKLegal]

I think that if you plan on having the sub play higher frequencies, say above 100 hz, the more stereo subs make sense. Personally I think stereo subs sound better all the time, especially with jazz and classical where low frequencies may localized in a particular channel and not evenly distributed across both channels.

I think if you go with full range speakers AND subs then a better setup would put the subs in the rear of the room out of phase.  In phase would probably overload the room.

My preference would be full range with out of phase stereo subs in the rear.  If I can't do that then I'd go with bookshelf's and stereo subs.  Full range speakers and 1 sub in the rear of the room out of phase would probably be great too.

[mlundy57]

I'm thinking of the subs doing sub duty, 80Hz or lower. Using my N3S example, the crossover would point would probably be around 60Hz.

Since full range speakers have the subs built in, I would think using full range plus additional subs would change the equation.   

Another way of looking at my question would be: which of the following is better for music and why:

(1) stereo subs (playing 80Hz or less) collocated with the midwoofers and tweeter (full range speakers),

(2) stereo subs (playing 80Hz or less) separated from the midwoofers and tweeter (bookshelf plus stereo subs), or

(3) mono sub (playing 80Hz or less) separated from midwoofers and tweeter (e.g. sub crawl)

Mike

[charmerci]

When I hooked up my new 12" sub along with the older 10" sub, the first that I noticed was not overwhelming bass (though I had to adjust down a bit) but the fact that the bass was tighter. This was without miking it or doing any calibration. Having more than 1 sub cancels out most nulls in the room. I'm certainly sold on multiple subs.

[SoCalWJS]

Wow. Loaded question. Gotta ask some back at ya.

How big is the room?
How low do you want to go? At what volume?
How much freedom do you have with respect to placement?
How many boxes are you willing to put up with?
What are your priorities? (strictly 2 channel? HT? WAF?)
Room treatment?
Listening preference? (what are looking for in sound - what are you willing to compromise on?)

Enquiring minds want to know....

[mlundy57]

Wow. Loaded question. Gotta ask some back at ya.

How big is the room?

Either of two rooms. One is 12' x 15' x 8' (most likely) and the other is 20' x 25' x 8'

How low do you want to go?

flat to 20Hz (servo)

At what volume?

     

70 - 75 dB average with peaks up to 85 - 90dB

How much freedom do you have with respect to placement?

fair amount, more in the larger room

How many boxes are you willing to put up with?

That would depend on the magnitude of improved sound quality

What are your priorities? (strictly 2 channel? HT? WAF?)

Listening preference? (what are looking for in sound - what are you willing to compromise on?)

Priority is music: classical, acoustic, vocal WAF is irrelevant for this discussion. She got the N3's (eventually a complete N-series 7.1 channel system) for her room. This will be for my room.

No special room treatment, at least not that I plan on.

However, my interest in this topic is a little more general. Let me pose the question in a different way.

Since frequencies below 80Hz cannot be localized, is there any benefit in reproducing them in stereo vs mono?

Then, if there is a benefit for stereo reproduction of the lows, is it better to have the low frequency drivers close to the mid and high frequency drivers (full range tower) or is it better to have them separated (limited range tower/bookshelf plus subwoofers)?

Mike

[bdp24]

Being a drummer (who also plays a little electric bass), this is an easy one: The open E string of the electric bass (please don't call them bass guitars. I'm looking at you, John Atkinson) and acoustic stand-up bass is 42Hz. That alone spells stereo subs, or at the minimum a x/o frequency of no higher than 40Hz. But there is also the matter of the out-of-phase information included in stereo recordings made in large rooms. That information includes VERY low frequencies. Plus, there are aesthetics to consider; I myself loathe lack of symmetry. Stereo subs is the ONLY way to go!

[bdp24]

"Since frequencies below 80Hz cannot be localized". Maybe so, but their overtones can be. Do you want them to come from left or right when the fundamental doesn't?

[SoCalWJS]

Thanks for all the additional info Mike.

I would go with the larger room and move the speakers as far away from the walls as you can stand. Full range speakers are generally better - many people think that bass can be localized much lower than 80 Hz, especially the harmonics. Multiple subwoofers give you a far better chance of being able to overcome peaks and nulls. You're not after anything incredibly low or loud. OB Servos are the best (IMHO). 2 OB in front and 2 in the rear (out of phase "swarm").

The main thing is to be flexible - don't be afraid to move them and alter the crossover points and slope. Measurements are your friend.

The above configuration is a great starting place, and IMHO, if you start your system with clean accurate bass, the rest of the system is free to live up to maximum potential.

[mlundy57]

Being a drummer (who also plays a little electric bass), this is an easy one: The open E string of the electric bass (please don't call them bass guitars. I'm looking at you, John Atkinson) and acoustic stand-up bass is 42Hz. That alone spells stereo subs, or at the minimum a x/o frequency of no higher than 40Hz. But there is also the matter of the out-of-phase information included in stereo recordings made in large rooms. That information includes VERY low frequencies. Plus, there are aesthetics to consider; I myself loathe lack of symmetry. Stereo subs is the ONLY way to go!

Thanks,

When running stereo subs, is it better to have them physically located with the midwoofers and tweeters like the are in the Super V and Super 7 or is it better to have them physically separated even though that means more boxes?

[bdp24]

Danny discourages mid-range/tweeter boxes being placed on top of subs, for the reason of low frequency vibrations being transferred into the upper box. As long as the two are no further apart than a certain amount of the wavelength at the x/o frequency (that amount you'll have to get from Danny) you'll be fine. I think .

[sharpsuxx]

1) Full Range Speakers - I would define this a true 3 way speaker with high and low pass cross overs at each crossover point.

Pros - Most Coherent top to bottom, single box solution    Cons- Harder if not possible to electronically manage room response, subwoofer has to cover some level of mid bass (very few drivers are capable of this), Typically higher costs

2) Bookshelf and Stereo Subwoofers.

Pros - Subwoofer can be dedicated to Sub bass or mostly sub bass, lower cost, bass can be electronically managed, more flexibility with placement, many options available in the bookshelf market, more even bass response  Cons - lots of boxes, harder to integrate woofer to midrange without a lowpass on the midrange (summation at the crossover point) Low WAF factor, harder to find HiFi quality subwoofers, sometimes disjointed or unrefined bass in the soundstage

3) Bass summed to one subwoofer.

Pros - Low cost, Ease of placement, Electronically managed bass  Cons - Almost impossible to properly integrate bass into the soundstage, uneven bass response, no localization of intruments with bass or sub bass, very few if any drivers are capable of doing the single sub solution properly, an HT received or something that can sum bass is often a poor processor for 2 channel music listening.

I tried to stay relatively factual but of course some of this is going to be opinion.  I personally like either stellarly implemented fullrange speakers (typically these are going to be expensive)  But what I own is bookshelf speakers which I eventually plan to low pass and add a bass woofer and bass management to the system.  It is hard in a non dedicated listening room to get "audiophile" bass.

Pros - Low Cost

[ricardojoa]

Dual subs should be better then a single sub, even though 80hz may sound be hard to localized. You may find it hard to localize in an open field, but if you are in a room, i dont think thats the case specially a 12db slope.
If you want to use one sub, it would IMO be better to cross slighly lower with a steeper roll of.

Whether you want your subs close or away from the mains, the most important thing is integration at cross over points. The difference, assuming perfect integration is that these two set up will result a different bass response, and im assuming you would want to take advantage of this if the sub are set away from the mains.
Also, IMO, impossible to have good integration if the subs are close to mains , without some procesding where it allows delay of front signals.

[brwsaw]

I find having (close to)full range speakers up front beneficial for casual listening or at night when you might be sharing common walls and or floor/ceiling but still want impact when watching movies , tv, games and 2.0 music. Those times when subs wouldn't be appreciated.

[mlundy57]

Thanks everybody.

If I understand correctly for the best music listening experience you want all frequencies (20Hz - 20kHz) to be reproduced in stereo from the front of the room.

The best way to do this would be with 2 enclosures for each channel (L&R). One of the enclosures on each side would cover the low frequencies and the other the mids and highs which could be floor standing or stand mounted. The two enclosures on each side would be placed where they provided the best performance and would not necessarily be right next to each other.  The caveat is that you have to have enough room to spread all these speakers out.

If you do not have enough space to physically place 4 separate enclosures across the front of the room then the next best option is to have two full range enclosures (20Hz - 20kHz) receiving stereo signals across the front. Each enclosure could look something like an MTM on the top and servo WW on the bottom.

The use of a single mono sub with a pair of less than full range mains (whether floor standing or stand mounted) would be better than not having the first (or first and second) octave(s) played at all but not as good as having those octave(s) reproduced in stereo.

Smoothing out bass response with additional mono subs would be a separate issue.   

Does that about sum it up?

Mike