Placing subwoofer in rear corner of room

[Kain]

Is it okay to place the subwoofer in a rear corner of the room? I am asking this because I might not have enough space up front. So, instead of placing the subwoofer in the front-right corner, can I place it in the rear-right corner of the room?

By the way, by placing the subwoofer on the rear-right corner of the room, it will be closer to the seating area. Won't this make the bass "greater" for the audience as it will be closer to them?

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Coming soon...

Home Theater:

Projector: (Still deciding)

A/V Receiver: Denon AVC-A11SR (European version of Denon AVR-4802)

DVD Player: Denon DVD-3800

Center: Klipsch RC-7

Mains: Klipsch RF-7s

Surrounds: Klipsch RS-7s

Subwoofer: SVS CS-Ultra w/Samson S1000 amplifier

[j-malotky]

Kain

IMHO - The main subwoofers should always try to be placed in the rear of the HT if at all possible.

JM

[boa12]

as long as the sub isn't set-up to be directional (which it shouldn't) it should go where u get the best balance of bass quantity & quality to your ears (& where u have room for it).

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My Home Systems Page

[DecibleLvr]

After trying out several thousand placement locations, I setteled on the rear of the room. As bass is considered "non-directional" the only real consideration is how it sounds to YOU. If you are just curious as to any technical reasoning, dont be. Just trust your ears. Enjoy!!

[HornEd]

Boa, as the owner of a highly renowned Velo HGS-18 sub has the right idea. The higher the quality sub, the more non-directional the output is likely to be (puts out bottom scraping lows without >80dB harmonics which create false localization).

Generally speaking, your best corner is most likely to be the best place for an adequate sub. If your full-range speakers provide the associated >80dB sounds, your ears will make you think those great lows are coming from that speaker... and not the subwoofer. This effect is so amazing that owners of great subs tend to check if their sub is working!

I had a half-a-dozen people over to see the opening scene of Saving Private Ryan... and they were amazed that the six KLF-30's in the HT could put out such deep bass on the explosions. They were even more amazed when I told them that all the deep bass was coming from the clean, quick, accurate, megawatt SVS 7' dual Ultra tower in the corner.

The three keys to great HT remain:

1. A better than average Center that is close/equal to your Mains.

2. A better than average Subwoofer to extend your Mains bass range.

3. A better than average side/surrounds that can provide discrete/ambient sounds intended by the mixer.

For multi-channel music, the Center is less important and the discrete aspects of the surrounds become more important than the ambient... and accurate positioning becomes more important. A pre-amp that converts 5.1 source to 6.1 for a monopole rear center... provides a big boost in ambient quality sound.

Clearly, a great bass remains the underpinnings of music or HT... and supplements for localization illusion of bass for all speakers in all conditions... whether they be monopole (full-range), dipolar (KSP-S6) or tripolar (WDST). That's why Klipsch put so much effort in creating the RSW-15. -HornED

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Photo update soon! -HornEd

[T2K]

What are the different types of surround speakers available and what are the differences?

There are three "common" types of surround speakers available today plus some unique types created by different speaker manufacturers.

"Monopole" speakers consist of a speaker or group of speakers all firing on the same plane in the same direction. This includes the vast majority of all speakers made. What people think of as "normal speakers" are termed Monopole. With regard to current surround sound formats, monopole speakers are the least desirable because they are the least effective in creating an "enveloping sound field" (ambience). They are good at localization, but that alone is not enough to produce the desired surround effect.

If you take a monopole speaker and add another speaker placed 180 degrees opposite of it (i.e. back to back) firing in the same phase, you have a "bipole" speaker. Firing in phase means all drivers on both sides are at the same excursion point at the same time. This creates the exact same sounds coming from both sides of the speaker at the same time. By design, Bipole speakers send no sound directly toward the listener. A bipole speaker will produce good "ambience" as all the sound is reflected off the walls of the room, but is not effective in producing "localized" sounds.

If you take the basic design of a bipole speaker with the rear facing drivers firing exactly opposite of the front, you have a "dipole" speaker. Dipole speakers produce a very diffuse sound, which is good for ambience, but, like bipoles, are not very effective at localization. Dipole design further reduces direct sound to the listening position.

Both bipole and dipole speakers should be mounted on the sides of the listening position and use reflected sound off of the walls to produce their effects. So if monopoles can offer localization but not enveloping ambience, and bi-pole/dipole speakers deliver ambience without localization, what can provide both important characteristics at the same time?

Klipsch produces a unique surround speaker that utilizes a technology called Wide Dispersion Surround Technology (WDST). Each WDST enabled speaker contains two Tractrix® Horn drivers and a woofer. Each horn covers a 90-degree arc and the combination of the two covers a full 180 degrees. This coverage gives excellent ambiance without having to use the walls to reflect sound. The controlled pattern of each horn (what we call "controlled directivity") leads to excellent localization of sounds because there is sound directed at the listening position, regardless of where in the room you are seated. And because the WDST surround speaker does not rely on wall reflections, it can be mounted in many different places in a room, leading to greater flexibility with placement. It is rare to have perfect side-wall positions available due to the placement of doors, drapes, furniture and such. WDST design delivers enveloping ambience WITH localization for the ideal surround sound result AND gives you the flexibility of placement to solve room design problems.

[HornEd]

Wow, I must really be a blockhead!

Common sense tells me that if a WDST speaker is getting sound to me without reflecting off something else than it is acting as a monopole speaker and not a bipole, dipole or tripole mechanically creating diffused sound by spraying it 180°.

"Ambient sound, in essence, is background noise that is provided by the "natural" environment. If this sound were not present in the projection of a particular scene -- specifically a scene in which the only sound is dialogue -- the scene would sound hollow and empty to the audience. The environmental noises can be recorded by a separate microphone during filming or in fact may be added by the foley artists in the remix of the scene." -Barnes & Noble Filmography

Clearly, ambient sound can be broadcast from any speaker type.

Unlike the essential wedge shape of the KSP-S6 that sprays sound out in a 180° pattern to bounce around the room to create diffuse sound that will eventually hit you wherever you may be in the room. All "WDST" speakers are built as trapezoids with the ends spraying horn tweeter sound over 90° each (making a total of 180°) on either side of the monopole woofer aimed at the sweet spot to assure some localization as intended by the audio engineer who mixed the DVD.

Obviously, audio engineers can mix diffuse sounds right into the DVD along with the discrete "localized" sounds. Of course, this technique would work better if the mixed diffuse aspect of sound could be broadcast from three or four speakers in the rear array... and I suppose that is why 6.1 and 7.1 configurations are creeping up on the consumer horizon. For the moment, mixers are increasingly treating the rear array somewhat like a phantom rear center.

My understanding of the KSP-S6 was that it was an improvement over the traditional THX certified surround by aiming its front and rear speakers at 45° into the room rather than straight forward and straight back. I further understand that it was referred to as a wide dispersion approach but, technically, that which was labeled "WDST" included a woofer aimed at the sweet spot and was introduced in the year that KSP-S6's were phased out.

The KSP-S6 forerunner of WDST speakers on through the RS-7 are wonderful speakers in many ways. They solve problems in speaker placement and commercial theater simulation that a single pair of surround monopoles couldn't solve... especially if mixed for the original THX version of surrounds.

Pointing one 45° end of an KSP-S6 or a WDST speaker at the sweet spot tends to make that end function as a wide mouthed monopole... and that has the other 45° end spraying sound against the rear wall to create an induced acoustic effect of having a phantom rear center. Hey, that's not a bad plan... it's just not what the sound engineers anticipated. And that's okay by me if it works for you. -HornED

PS: I'm sorry Keith, but this time your explanation didn't pass the PWK Yellow Button test.

This message has been edited by HornEd on 04-27-2002 at 06:56 AM

[T2K]

Oh it's not MY explanation ED. That information came verbatim from this site.

[Kain]

Thanks for the replies.

So you are saying that subwoofers should be placed at the rear corners of the room?

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Coming soon...

Home Theater:

Projector: (Still deciding)

A/V Receiver: Denon AVC-A11SR (European version of Denon AVR-4802)

DVD Player: Denon DVD-3800

Center: Klipsch RC-7

Mains: Klipsch RF-7s

Surrounds: Klipsch RS-7s

Subwoofer: SVS CS-Ultra w/Samson S1000 amplifier

[HornEd]

KAiN64, since you are using SVS subs I think you should take into consideration what Tom Vodhanel told me... "Pick your best reflective corner and put your subs there." The clean, crisp, dynamics of SVS subs (or other quality sub like a RSW-15) will gain strength from the floor and two walls and cover your listening area wall-to-wall in a fraction of a second.

Front or rear locations are only important if you had a much lesser sub with harmonic localization problems. Remember, even the mighty Klipschorn derives much of its power from maximizing a corner advantage... but it is dealing with frequencies that are primarily above 80dB and thus are localized.

Keith, I realize that you lifted the above surround text from the Home Audio FAQ that attempts to explain in simple terms the complexities of acoustics and psycho-acoustics that bring so much joy to average Klipsch owners. And, taken in context the quote makes more sense... but thrusting it into this discussion of the interrelation of speakers with subwoofers and the placement thereof could be confusing.

Here are some problems I have with the quote. On the one hand it states "Both bipole and dipole speakers should be mounted on the sides of the listening position and use reflected sound off of the walls to produce their effects." and later, in reference to WDST's 180° angle mounted Tractrix horns claims, "This coverage gives excellent ambiance without having to use the walls to reflect sound." Both statements are essentially true but can be misconstrued IMHO.

There is nothing "magical" in a WDST speaker that creates a more diffuse sound than the same Tractrix horn in a monopole... except the WDST speaker has two of them aimed at different angles to envelope the room in direct sound that is reflected to create an evenly diffuse sound in most listening areas. Obviously, strategically placed monopoles can produce a similar effect (and with a better tone & timbre match, IMHO).

Klipsch has created a small but effective listening room acoustics problem solver in WDST that recognizes the need for more direct sound toward the sweet spot than was provided in the KSP-S6 design. Dual angled Tractrix horns in a trapezoid is indeed beneficial with surround tracks that are primarily mixed with ambient sounds in the recording studio... and particularly so in breathing life into the vast sea of ProLogic source material.

By spraying the entire room with these pre-recorded ambient sounds, anywhere you sit will be under the broad spectrum of the horns theoretically. But I have found Tractrix horns to be a bit more directional than that despite the degree of dispersion. The reason for toe-in on main speakers is an example of that directivity as I understand it. But, obviously, as the direct radiated sound from the splayed Tractrix horns reflects off of room objects... the recorded ambient sound becomes so diffuse as to become non-directional.

An example of the phenomenon can be heard on the popular "Audio Essentials" Set-Up DVD by switching from stereo to multi-channel formats during the test... as suggested in the DVD.

Many people on this forum with large listening areas derive excellent ambiance with Klipsch monopoles rather than the Klipsch WDST approach... my hero Q-Man for example... and there are others, like SteveP who blend K-Horns and KSP-S6's in acoustic bliss!

The FAQ section is written to help more people in the most common situations... and is not intended to be a definitive treatise on the science of acoustics. As always, my concern is offer personal opinions that cut through the rhetoric and "knee-jerk responses" to encourage folks to experiment with their acoustics space with an eye toward moving forward on the upgrade trail.

My HT and music rooms have and abundance of appropriate ambient and discrete sounds produced by Klipsch monopoles... without the aid of WDST. By no means should anyone infer that WDST might not be the best solution in their listening area. I think that the character of the FAQ suggests that monopole speakers cannot be used as effective side/surrounds... and I know that to be a less than accurate impression when reflected upon the experience of some of us on the Forum.

Thus, I do not believe that it is fair to ridicule those of us who choose a Klipsch path that our ears say is a better way to go when we try to share our experience on this Forum. This is a place to explore and expand our knowledge... a place to share what we learn with others... a place to find better answers when we have fallen into poor conclusions. A friendly place where a helping hand serves better than a testy comment. Peace. -HornED

This message has been edited by HornEd on 04-27-2002 at 08:54 AM

[cakid]

One thing you'll want to keep in mind with rear room sub placement is the phase switch setting (if your sub has one). If you are placing your sub in the rear of the room, but facing it toward the center of the room, you should set your phase switch to (0 degrees). If you are placing your sub in the rear of the room, but facing it toward the front of the room, you should set your phase switch to (180 degrees). I just wanted to mention that, in case you had not thought about it.

HornEd, I had to smile when I read your postings and saw the pic. Your "wall of audio/video" reminds me of how I am. It's fun to read these postings.