[Russell Dawkins]

I actually was answering your question in a literal way, as I saw it.

I really would love to have a listening room with the acoustics I described, and in fact did design a forest music studio for a friend that employed these devices, all except the ceiling, which at the time was envisioning as a sliding hard shell. That, and the floor plan was pentagonal.

You just thought I was being sarcastic - in fact I was more than half serious and attempting to trigger creative thought in the matter.

[*Scotty*]

Great bass is in the ear of the beholder as it were. Some, like Elizabeth, are satisfied with the bass produced by their loudspeakers and feel no need for the addition a sub-woofer.
 For those of limited means just starting out the available options are also constrained.
I would have to say it depends on the system and the room, which is not much of answer or a recommendation.
I don't know of a single magic bullet approach to recommend to someone just starting out. If they have purchased a sub-woofer that actually works they have also unwittingly bought a problem as well, standing waves. Then the search starts for the solution to the bass problem created by the sub. Cue the entrance of equalizers and or room treatments.
 Whether a person feels the need to try adding additional sub-woofers to achieve a better result will depend on how dissatisfied they are with results of the first two fixes.
Of course the first step towards solving any problem is realizing you have one in the first place.
Scotty

[JohnR]

I don't really understand the question. I don't think it makes sense to think in terms of the "most significant" thing - any more than it does to ask "which is first"? All of these things are just tools. Does it make sense to ask which is the most significant tool you will use for building your house? Ask a dozen chippies and you may or may not get some consensus on their favourite or "go to" tool but it's not like you are then going to make everybody use only that tool.

Plus, everybody has their own biases/preferences/needs. Some people heard a dipole speaker once and didn't like it, and from then on go on the forums saying dipole speakers don't sound good and coming up with reasons why you shouldn't use them. However, in my experiments, the simplest way to get excellent bass response, both in terms of flatness and meeting the decay time criteria in http://www.hifizine.com/2011/06/bass-integration-guide-part-1/, was to use a single dipole sub located close to the listening position. However, that does require DIY, which some people can't or won't do, and it's not going to work for a very large listening area, which some people apparently need. Others swear by using multiple subs with delay/phase adjustments between them - but I found that using delay between multiple subs to get a flat steady-state response made it sound weird. I could have just not done it right, that's certainly possible. And anyway, I would prefer to not have bass in the whole room, but just in the LP - because that way I can listen late at night without worrying about the neighbours.

So, you know, faced with a question that makes no sense asked with a tongue-in-cheek phrasing, I guess you would have expect some tongue-in-cheek responses

Having said all that, if your question is about improving bass response, then I suppose my answer would be the most significant thing you could do would be to measure (and analyze) what you have and understand how your room behaves. I mean using a sweep, not pink noise or test tones. Then be prepared to experiment.

Hope this answer is more helpful

[jtwrace]

I suppose my answer would be the most significant thing you could do would be to measure (and analyze) what you have and understand how your room behaves. I mean using a sweep, not pink noise or test tones. Then be prepared to experiment.

Yay.

And ultimately unless you do this you do NOT have a clue what is actually happening in your room regardless what approach you take.

[medium jim]

JohnR:

I guess there is some truth to what you say, yet I would have hoped that my initial post would have gave some direction, many figured it out....then my attempt at humor in the title didn't help.   

I'm going to wipe the slate and start over....

Jim

[medium jim]

For clarity, I've retitled the question and cleared the vote.

Thanks,
Jim

[medium jim]

For me it was Dual Stereo Subs.  It smoothed out the room, gave me proper instrument placement in the soundstage and made integration much easier.  Next was some simple eq'ing via passive High Pass Filters, which were designed just for Magnepan Speakers.  The difference was dramatic. 

Jim

[medium jim]

In that I mucked this one up from the beginning, I non-stickied it.  If it gets some steam behind it I will make it a sticky thread as intended.

Sorry for my initial title screw-up....

Jim

[mgalusha]

Voted for multiple subs in mono but I actually have both, 3 in mono and 2 in stereo. The ones in stereo are used as stands for the mains since my mains drop off steeply at about 60Hz, the other three are used for smoothing out the modes. I also have a quite a bit of treatment in the corners and use some eq on the 3 subs around the room for smoothing out the modes. Is it perfect, nope but it is pretty darn good. Yes, it's a dedicated room so having 5 subs and assorted crap (xo, wires, amps, etc) is allowed.

[medium jim]

mgalusha:

Great post!  The funny thing is, if you tell the average guy on the street that you have five subs in your system, they will think you are nuts and have way too much bass.  In reality, the bass isn't over the top.

The best system I've ever heard had four subs, all in stereo, two on the front wall and two on the back wall.  The mains were Avantgarde horn trios.  The two front subs actually are bass horns.

Sure there was plenty of slam, but it was exactly how the music was performed/recorded. The room was about 30x20', no room treatments other than some large potted plants.

My room is square and only 16x15' and stereo subs on the front wall gets me nearly as good.  Not sure if two more subs would be beneficial.

Jim

[JohnR]

There is such as thing as too much bass - even if it measures flat steady-state, it can still not sound right. The number of subs makes no difference. I think it's necessary to make the right trade-off between low-frequency response and low-frequency decay time.

[*Scotty*]

You can certainly run into this problem in a basement, the only surface that the energy can leave through is the ceiling. You can have this happen if your full range speakers are actually flat to 20Hz and designed to be used in an above ground room with conventional wood frame construction. When they are placed in a basement listening room the total energy emitted below 150Hz and trapped in the basement can easily exceed the energy emitted by the mid-ranges and tweeter.
When this happens I am not sure that even multiple sub-woofers operated out of
phase can save you from a hopelessly bass heavy balance.
 A friend of mine ran into this very problem when he built a showroom for audio in his basement.
Full range speakers designed to be used above ground in medium to large rooms could not be used in his basement even though he had a 12in. sub operating out of phase at the rear of the room.
There was nothing he could do to solve the problem except lug the 185 lb. monsters back up the stairs to his living room.
 I think you have a lot more flexibility with a sub and satellite combination, you can always turn the sub down to compensate for amount bass lost through the rooms walls.
Scotty

[*Scotty*]

Addendum to the previous post, the problem of too much bass is related to the cone area of the drivers that cover the bass region and the size of the room the speaker is operated in as well as the type of building construction used. People are frequently advised to buy a speaker that is appropriate to the size of their room and its construction.
 I am unaware of any published rules or recommendations covering this subject that are applicable to all brands of loudspeakers. This kind of problem is frequently masked by the resonant behavior of the room below the Schroeder frequency. An abundance of bass driver cone area and the resulting increase in radiation efficiency at bass frequencies exacerbates the standing wave problems.
 With the advent of the computer as a source, compensating for a speaker to room mismatch in the digital domain is now a viable option.
 This would allow you to buy a speaker with substantial bass capability and optimize the speaker to room relationship with virtually no concern for the size of your listening room. This gives you an increased ability successfully relocate your stereo system and deal with whatever fate puts in your path.
Scotty

[medium jim]

Addendum to the previous post, the problem of too much bass is related to the cone area of the drivers that cover the bass region and the size of the room the speaker is operated in as well as the type of building construction used. People are frequently advised to buy a speaker that is appropriate to the size of their room and its construction.
 I am unaware of any published rules or recommendations covering this subject that are applicable to all brands of loudspeakers. This kind of problem is frequently masked by the resonant behavior of the room below the Schroeder frequency. An abundance of bass driver cone area and the resulting increase in radiation efficiency at bass frequencies exacerbates the standing wave problems.
 With the advent of the computer as a source, compensating for a speaker to room mismatch in the digital domain is now a viable
option. This would allow you to buy a speaker with substantial bass capability and optimize the speaker to room relationship with virtually no concern for the size of your listening room. This gives you an increased ability successfully relocate your stereo system and deal with whatever fate puts in your path.
Scotty

For the most part, I'm a minimalist, less eq, room correction the better.  At the same time it would also be a shame to spend a lot for room treatments only to move or relocate.   

I agree that choosing the right size Sub is important to the room. 

Jim

[*Scotty*]

Jim, I suppose one of the easiest mistakes a beginner to the hobby could make is to under-estimate the size of the sub they need.
They're told that this 10in. sub will do the same job as a 12in. or 15in. sub. No one explains to them that in order for the smaller woofer to play as loudly as the bigger woofer it must be able to move the same volumetric amount of air displaced by the bigger woofer.
Scotty

[medium jim]

Jim, I suppose one of the easiest mistakes a beginner to the hobby could make is to under-estimate the size of the sub they need.
They're told that this 10in. sub will do the same job as a 12in. or 15in. sub. No one explains to them that in order for the smaller woofer to play as loudly as the bigger woofer it must be able to move the same volumetric amount of air displaced by the bigger woofer.
Scotty

Absolutely, there is no way I could get away with two 8" subs in a bigger room, at the same time, a single 10 or 12" would work.  I agree that there needs to be some sort of scale to aide in the selection of the right size sub(s) for different rooms based on total sq ft.

Bigger isn't always better.

Jim

[JLM]

Scotty,

IMO its a factor of room volume, not construction that leads to "true" bass overloading.  By "true" I mean a response without a frequency emphasis beyond standing waves.  Unfortunately for the space constrained, bigger is better. 

I had a big 3-way 30 years ago that overloaded 5,000 cubic foot spaces, but sounded marvelous in a 20,000 cubic foot space (with a NAD 20 wpc amp). 

BTW I agree with you that dual subs at opposite ends of the room is the bass solution, if you don't want to live in a tent.

[7x57]

At the lowest frequencies where the bass waveform would be much longer than any room dimension, you will not have standing wave problems. If you are going that low, then your woofer cones are merely pressurizing and depressurizing the room. Since I listen in a slightly smaller than average room, with the longest dimension no more than 20 feet, and the ceiling height only 8 feet, this pressure mode sets in below 50Hz. My VMPS RM-1 with two 8" woofers and a 10" PR goes about 5Hz lower than my Vandersteen Model 2Ci with a single 8" woofer and a 10" PR. I am not talking actual efficiency and SPL for a power input here, but where each speaker rolls off relative to its higher frequencies. The woofers and PR just can't keep shoving out further and further but have a limit. For the same amount of excursion, you need more surface area to reach further down in frequency in a given room size. The system resonance also determines the rolloff point below system resonance as you need more power below system resonance to get the same excursion from the loudspeaker. I measured a speaker resonance of about 35Hz on my 8" VMPS woofer, which explains my -3dB at 31.5Hz and -6dB at 25Hz readings.

Single sinewave notes are not played in real music, and higher notes interact as to how you psychologically perceive lower notes, so a SPL meter and your ears are two different things. But, the size of your woofer area and your speaker syetem resonance mainly determine how low you can go in the bass. If the second harmonic and all higher harmonics are played in the correct proportions in your bass note, then your brain will recreate the fundamental frequency.......but your body will not feel the vibe. Also, the 24dB/octave rolloff of a bass reflex speaker and the 12dB/rolloff of an acoustic suspension speaker means the the acoustic suspension speaker will appear to go far lower in bass if they both have the same -3dB point in your room. The Ampeg SVT bass amp used acoustic suspension speakers to roll off earlier but actually go lower and more linear than bass reflex systems, by using room boost to equalize the sound.

At one octave below the -3dB point, the Acoustic suspension speaker -15dB, but the BR design is -27dB (and totally undamped and probably doubling and farting). If you add 6dB of room boost to each figure, you get -9dB and -21dB respectively. The Acoustic suspension is 12dB louder, or over twice as loud by perception, with about 16 times the acoustic energy.

[*Scotty*]

7x57,

At the lowest frequencies where the bass waveform would be much longer than any room dimension, you will not have standing wave problems. If you are going that low, then your woofer cones are merely pressurizing and depressurizing the room.

Where did you find this information?
Scotty

[Wayner]

Bass quantity does not equal bass quality. In fact, too much bass is way worse then a speaker or system that is a bit shy on the bass. The real question is can one detect the bass note being played. In the lower octave registers of bass, that ability to detect tone becomes very fleeting, simply because the wave is so long, the human ear can't detect it's pitch. We perhaps can feel it (if it's low enough), but then this very low energy takes a long time to dissipate, slurring the bottom end to end up sounding like many "boom" boxes installed in cars. The kids who have this think they have "great bass" but it's really a one note wonder. This brings up this thought again, is there such a thing as too low a bass (to be practical)? After all, this very low energy is going to require lots of amplifier power, and will make everything that is loose, sing in harmony, like pictures on the wall, glasses on the table, even windows.

In another thread, a comment was made that church pipe organs can go down to 16hz. Well, that is steam power, not electrical power from an amplifier and the church is going to be huge in scale compared to an average listening room, so the comparison does not hold water.

So that is why I voted that it depends on the room and the system. Obviously, it would be nice to have speakers that can produce tones (in a usable undistorted value) in the neighborhood of 30-35hz or so (I'd be happy with that) and that the room is large enough for those frequencies to develop. Then I'd hope that everything is nailed down to eliminate vibrations. And yes. there is the standing wave problem. Room corners seem to be a haven for this, so perhaps treatment is required, certainly speaker position within the room boundaries will be the single, most important factor.

Wayne