Why aren't more speakers designed to be put against the wall or in a corner?

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Doublej

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Why do so few manufacturers have speakers to be positioned against the wall or in corners? It seems to me that for many people having speakers two or three feet from the wall is not realistic.
« Last Edit: 7 Oct 2006, 11:54 pm by Doublej »

Soundbitten

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That's an excellent question .

John Casler

It is a matter of psychoacoustic interaction with room surfaces.

The closer the speaker is to the room surfaces, the more room distortion is created.

Mathew_M

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I think Bose sound better against a wall, in the corner.  Of course they don't have any real highs or lows that would cause massive room reflections.  :wink:

Scotty

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 If loudspeaker is designed to deliver flat frequecy response when placed near a room boundary, specifically a room corner, it will only deliver flat response from that location the reverse condition also holds true. This design eliminated the need for baffle step compensation in the crossover. It also loads the room nodes at the maximum amount possible. Bass response will be very flat except at the rooms resonant frequencies.These aspects of the  design severely limit the end users placement options making them less desirable than a speaker which is more or less flat at several locations in a room. Also if the only corner you have available places the speaker behind something the midrange and high frequency dispersion into the listening position
will be compromised resulting non-flat frequency response and poor imaging.
See the link to Allison Acoustics for a discussion of the advantages of integrating a loudspeaker with the room. http://www.allisonacoustics.com/
http://www.allisonacoustics.com/one_system.html
http://www.allisonacoustics.com/history.html
The design actually appears to minimise undesirable room interactions by loading the room evenly across the bandwidth that the speaker reproduces.
Scotty
« Last Edit: 9 Oct 2006, 02:40 am by Scotty »

JLM

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Klipschorns do exactly that.  They use the room corner to complete their folded bass horn.  Those sorts of designs need approximately 6 - 10 feet of wall on either side of the corner to achieve the full effect.  The problem is finding suitable rooms (that have two such adjacent corners and you can sit far enough back to allow the horns to blend).  It's hard to believe such a room is so hard to find, but just look at some of the rooms we all use for listening and you can see why stereo killed the Klipschorn.

This is a very efficient way to develop bass, however it makes producing depth in soundstage much more difficult.  One solution I've seen is to provide an archway towards the front of the room where the small corners can be used, yet provide room behind the speakers.  It provides a tradeoff between bass output and depth of soundstage.

Duke

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If a speaker isn't designed with the expectation of a wall or two being very close by, two problems can arise when you place it near a wall or in a corner:

First, midrange and/or lower treble energy that normally would have wrapped around the enclosure will now be reflected back toward the listener early enough that it will have a strong effect on perceived timbre, resulting in audible coloration.

Second, frequencies below about 200 Hz will get the benefit of boundary reinforcement, which can cause excess midbass thickness and bass boominess.

Neither of these problems is insurmountable.  Use of a horn or waveguide, or even just a wide front baffle, will reduce or prevent coloration in the midrange and lower treble region by controlling the radiation pattern.  Or, the speaker just can be designed from the outset to give a tonally correct presentation when that early reflected energy is included.

By not designing in an artificial midbass hump, boundary reinforcement probably won't overly thicken the midbass region.  Again, a wide enclosure helps, as does a large diameter midbass driver (because it's more directional).   Finally, a low-q sealed enclosure or EBS-tuned reflex enclosure would be less likely to become boomy when placed up close to a wall.  Corner placement is more of a challenge, and unless the speaker were specifically tuned for corner placement (think Audio Note), some boominess is still likely.  The option of tuning the enclosure much lower than normal would help smooth out the bass with corner placement, transforming what would have been boom into greater depth and impact.

The bass boost you get from boundary reinforcement is the closest thing to a free lunch there is in loudspeaker design.  Someone correct me if I'm wrong, but I think Ed Schilling's Hornspeaker is intended to take advantage of boundary reinforcement to augment the bass from his backloaded horn enclosure.  I've recently designed a couple of speakers intended to address the issues involved and work well when placed near room boundaries, and will post something about them in Marketplace sometime soon. 

Duke

bpape

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Not to mention the fact that when corner loading anything, you're exciting every room mode to the max.  Since EVERY room is different, there is no way to compensate for this in the xover.

Bryan

TONEPUB

Naim is a mfr that voices a lot of their speakers to work close to the wall.
They claim that smaller rooms in Europe dictate this.  I've had great luck
with my Arivas, as I too have a very small living room.

Bill Baker

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I think a lot of it has to do with soundstaging. There are still a few companies that design their speakers for placement close to the wall or in corners. Audio Note speakers is the first to come to mind.
 I have even decided to to do this with our Musica Bella loudspeakers. The wall mount speakers are obviously designed this way from the start. In the standmount speakers, the differences are in the crossover. One of the benefits of  this crossover is a 3dB gain in efficiency not having to use any baffle compensation.
 It's all a matter of personal preferences. You do sacrifice a few things having speakers mounted against the wall with soundstage and imaging being the key elements.

Wayner

Buy some Dynaco A25's from *bay. They are "bookshelf" speakers made to be placed fairly close to the wall on a bookshelf, or even hung on the wall (they come with built in brackets), and are just fine for a smaller room. They will image like crazy. I can hear near perfect stereo in any location in my smallish studio with the speakers mounted 4 feet up from the floor and about 8 feet apart. Yes, it's not an ideal spot for them, but they are forgiving speakers. These speakers were designed with some common sense about speaker placement, IMHO.

W

sharper

North Creek / North Acoustics offers two bookshelf models which are designed to be placed near the rear wall. I owned the Spirits which were quite good.

EMM801

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Buy some Dynaco A25's from *bay. They are "bookshelf" speakers made to be placed fairly close to the wall on a bookshelf, or even hung on the wall (they come with built in brackets), and are just fine for a smaller room. They will image like crazy. I can hear near perfect stereo in any location in my smallish studio with the speakers mounted 4 feet up from the floor and about 8 feet apart. Yes, it's not an ideal spot for them, but they are forgiving speakers. These speakers were designed with some common sense about speaker placement, IMHO.

W
There were reasons the A25 was the best selling speaker of all time, and you hit on several. Many audiophools (including me) had them in their first system. One of their best qualities was being an exceptionally easy amplifier load with a much flatter impedance curve than most speakers of that (or this) era.

Mike Dzurko

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The A25 was a wonderful speaker . . . very well designed and implemented.

Anyone who's heard a pair of our Emerald On-Wall speakers will tell you that on-walls can sound terrific. As others have mentioned, you get a gain in efficiency or greater extension depending on how it is designed. The only thing you give up is image depth . . .  and if you must position your stand mount or floorstanding speakers close to the back wall, you're not going to get that much depth either.

BobM

A good friend has original Klipshorns in a room that he set up especially for them, but perhaps not deep enough to let them blend properly. Driving them with a 2 watt SET amp. Incredible dynamics and inner detail, but no center fill or soundstaging to speak of. Very lifelike and engaging with great natural timbre.

But that doesn't completely work for me, since I'm an imaging and soundstaging nut. Of course I want it all too.

Enjoy,
Bob