During the mid 70's I was involved with a small amateur theatre built in part of a Victorian house. As part of that install there were a couple of loudspeaker baffles installed on the wall, left and right sides of front-of-house, for interval music and some ambient sounds. The corner of the two walls became the speaker walls, with only the triangular tops and bottoms of the cabinets made to complete the sealed enclosure. The sound of that installation was excellent, with a nice warmth to the bass, helped by the wood, stone and velvet of the theatre auditorium. Although we ran them with just a 30w/channel amplifier there was more than enough sound for a good thunderstorm or party music.
That all said, I started again looking into corner speaker designs wondering why more use isn't made of using a solid brick wall for two of the speaker sides in a triangular shape. All design notes I have looked at suggest the 12dB boundary effect bass lift (or18dB if in the corner of three boundaries) is mostly undesirable, and I would agree, so why did ours sound so good... even without reducing low frequencies on the amp?
I've attached the only [very rough] picture I could find showing one speaker in situ from those days.
The speakers were actually the units from the KefKit 1 (B200 and T27+ crossover), and the baffle size was approximately 14in x 36in (35cm x 90cm), which would give an internal volume of around 1800 cu.in (~30Litres). From the Kef specs the recommended volume for the speakers was 21litres.
Would anybody with more knowledge of speaker acoustics be able to advise why they sounded so good yet this design is not made more of these days?
That all said, I started again looking into corner speaker designs wondering why more use isn't made of using a solid brick wall for two of the speaker sides in a triangular shape. All design notes I have looked at suggest the 12dB boundary effect bass lift (or18dB if in the corner of three boundaries) is mostly undesirable, and I would agree, so why did ours sound so good... even without reducing low frequencies on the amp?
I've attached the only [very rough] picture I could find showing one speaker in situ from those days.
The speakers were actually the units from the KefKit 1 (B200 and T27+ crossover), and the baffle size was approximately 14in x 36in (35cm x 90cm), which would give an internal volume of around 1800 cu.in (~30Litres). From the Kef specs the recommended volume for the speakers was 21litres.
Would anybody with more knowledge of speaker acoustics be able to advise why they sounded so good yet this design is not made more of these days?
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There are many factors, you can't just declare it will sound good or bad unless it was designed with the utmost consideration for the location.
Corners can be very good when used properly. The thing about your question I'd want to point out is that the effect varies at different frequencies. Perhaps some of what you read has to do with room modes and applies mainly to the lowest frequencies. These can be balanced with carefully located subs.
Corners can be very good when used properly. The thing about your question I'd want to point out is that the effect varies at different frequencies. Perhaps some of what you read has to do with room modes and applies mainly to the lowest frequencies. These can be balanced with carefully located subs.
Thank you AllenB. I completely agree. I can add that the initial installation will have been made on the basis of confidence in the product, with no real consideration into room modes, except that the environment had generally low reverberance and good damping, with few directly reflecting surfaces. Quite similar to a studio control room actually. My feeling is that the corner mount lifted the LF end of the response, but I don't really know the range of frequencies that would have been lifted. We certainly didn't use (or need) any subs.
I also wondered if with the benefit of applying some acoustic maths (looking to those with experience in this field on this forum) to this layout there was a predictable benefit to using triangular, non-internally reflective, loudspeaker enclosures, mounted in line with two boundaries (walls), which themselves may not have contributed significantly to reflections as a result.
I also wondered if with the benefit of applying some acoustic maths (looking to those with experience in this field on this forum) to this layout there was a predictable benefit to using triangular, non-internally reflective, loudspeaker enclosures, mounted in line with two boundaries (walls), which themselves may not have contributed significantly to reflections as a result.
Subs are also often used to augment the characteristics of the space.
Can you tell me more about the triangular enclosures.. are you talking about the inside or the outside. How are they located.
Without evidence, my own theory for why corners aren't used more is that people seek "imaging" and seek to avoid early reflections and so on...vs your (informed) observations that limiting the radiation angles and taking advantage of boundary support can be beneficial. +1 to Allen's remark about the transition. You're sewing pieces of response together.
I guess I'm reading the inquiry about internal reflections (?) For an enormous (..say 20-30ft3 etc) infinite baffle (empty sealed but lined), IMO, you can probably damp-out the top-to-bottom standing waves with a couple cross-batts of fiberglass if they cover the whole cross-section--and line the walls normally for the rest. If things are tight (driver to walls < say 1/2 diameter), it may make sense to use the (painful to construct) angled enclosure walls in addition to the lining. If it's for a permanent installation, it might be worth a throw-away proto to measure/hear/test with, FWIW.
I guess I'm reading the inquiry about internal reflections (?) For an enormous (..say 20-30ft3 etc) infinite baffle (empty sealed but lined), IMO, you can probably damp-out the top-to-bottom standing waves with a couple cross-batts of fiberglass if they cover the whole cross-section--and line the walls normally for the rest. If things are tight (driver to walls < say 1/2 diameter), it may make sense to use the (painful to construct) angled enclosure walls in addition to the lining. If it's for a permanent installation, it might be worth a throw-away proto to measure/hear/test with, FWIW.
listening test between horn loaded systems / corner loaded systems / free standing systems shows that the bass can profit from room boundary gain and horn loading
so called "room installation" could be used much more and is most easily realized if you already build a house.
But nothing prevents people who have property of their own for just adding a wall at 10cm before a wall just to integrate there elegantly loudspeakers into a solid wall giving large drivers plenty of volume in a perfect solid enclosure.
Given how easy this is its very rare that this is done. Material could be lightweight YTONG certainly stable enough for the purpose.
But nothing prevents people who have property of their own for just adding a wall at 10cm before a wall just to integrate there elegantly loudspeakers into a solid wall giving large drivers plenty of volume in a perfect solid enclosure.
Given how easy this is its very rare that this is done. Material could be lightweight YTONG certainly stable enough for the purpose.
There’s simply not enough info in your post or picture to support your experience. Corner loading can be a significant benefit but can’t realize your assertion than no subs were needed in a HT use case…….not possible with the B200 driver.
As pointed out earlier, stereo or spatial imaging from 2 corner loaded systems is pretty aweful….the sources are easily locatable as the directivity index is is fixed to the first reflections.
As pointed out earlier, stereo or spatial imaging from 2 corner loaded systems is pretty aweful….the sources are easily locatable as the directivity index is is fixed to the first reflections.
Not if done right. The corner can be excellent but you can't just put any speaker there.
Hmm, really? These corner speakers have a huge, deep, wide soundstage and stereo separation. It's a small room (spare bedroom).
Attachments
Still…..your experience doesn’t offset the reality of power response……..the bosom of stereo imaging.
Facts to the contrary notwithstanding? Just joshing you of course, but seriously, how do corner speakers automatically fail at imaging?
Do you mean the "skinny speakers pulled away from walls" trick, where instruments hang in the air? These speakers don't do that exact trick, but they have a massive soundstage and great stereo.
Do you mean the "skinny speakers pulled away from walls" trick, where instruments hang in the air? These speakers don't do that exact trick, but they have a massive soundstage and great stereo.
First, there is a very personal, emotional side of this installation. If you remember these times in the 70's it is not only the sound system, but the nice people you meet, discussions you had etc.
It may be that today, with the same installation you would not be so impressed. People that visited private theaters at that time, did not expect an earth shattering performance. They brought their fantasy and imagined in their own minds what was missing. Like three trees on the stage, which are there to let you immagine the szene happening in a dark wood. So the same with sound effects.´Something sounding a bit like a far away thunderstorm and a few flickering lights helped to imagine what kind of nasty weather it could be.
Today an audience needs 3-D effects and bass that shakes them to the last bone, just to be somehow impressed. That is what 50 years devolution of culture and education have achieved.
Now the technical side.
If you put a speaker in a corner you may not always end up with too much bass. You can simply design a woofer that would have not enough bass in the room, by enlarging the box or using a low Qts chassis. So you end up with a Qtb around 0.5 maybe a little more. The corner placement then extends the low end, while the large cabinet improves efficiency. So a small amp will be enough to drive them.
It may be that today, with the same installation you would not be so impressed. People that visited private theaters at that time, did not expect an earth shattering performance. They brought their fantasy and imagined in their own minds what was missing. Like three trees on the stage, which are there to let you immagine the szene happening in a dark wood. So the same with sound effects.´Something sounding a bit like a far away thunderstorm and a few flickering lights helped to imagine what kind of nasty weather it could be.
Today an audience needs 3-D effects and bass that shakes them to the last bone, just to be somehow impressed. That is what 50 years devolution of culture and education have achieved.
Now the technical side.
If you put a speaker in a corner you may not always end up with too much bass. You can simply design a woofer that would have not enough bass in the room, by enlarging the box or using a low Qts chassis. So you end up with a Qtb around 0.5 maybe a little more. The corner placement then extends the low end, while the large cabinet improves efficiency. So a small amp will be enough to drive them.
Not what I'd expect someone to say, I had no such problem 😉 What have you tried that's lead you to say that?
As you mentioned, it’s a small space so likely with corner loading it couples to the room in the low frequencies very well…..that’s half the battle…..a very good half of the equation. But to answer your question…..yes……the narrow baffle upper midrange through the treble systems image magnitudes better in a mildly reverberant environment….or in other words….a somewhat natural power response. Some folks love headphones…..some despise them……….while some can do both. Floating in the air?…..I think that question answers itself for those who have experienced it and can recreate it within their 3D space. Take those enclosures in the corner and turn off the horn…..replace it with a competent small box MT section on stands out in the room?……now you’ve got my attention!
It's fun for sure. Isn't it only one trick among others, though? I have not been thinking it outweighs the other tricks.
Corner loading will increase bass
that is well known.
Far as getting strange dips.
It is a relation to side walls and very large planes=
Ceiling and floor.
So with bass you stay closer to one or the other.
Sound doesn't care if the " room" is upside down.
So just pick one.
Floor or ceiling.
High mounting above ear level.
Your only concern is highs.
Ironically the typical horizontal maximization
with vertical speakers. Is probably not as relevant.
Trying to aim sound more downward.
In all simplicity even Western electric then Altec
made simple utility boxes with 30 degree baffles
to point the speaker downwards for high mounting.
looking at the picture, the simple tilt from the roofline
seemed to work well.
Wont waste much time discussing the magical
imaginary concepts of imagining.
Its in the recording. and you can spread your speakers
closer or farther apart to emphasize it. THE END
Every recording is different from there.
that is well known.
Far as getting strange dips.
It is a relation to side walls and very large planes=
Ceiling and floor.
So with bass you stay closer to one or the other.
Sound doesn't care if the " room" is upside down.
So just pick one.
Floor or ceiling.
High mounting above ear level.
Your only concern is highs.
Ironically the typical horizontal maximization
with vertical speakers. Is probably not as relevant.
Trying to aim sound more downward.
In all simplicity even Western electric then Altec
made simple utility boxes with 30 degree baffles
to point the speaker downwards for high mounting.
looking at the picture, the simple tilt from the roofline
seemed to work well.
Wont waste much time discussing the magical
imaginary concepts of imagining.
Its in the recording. and you can spread your speakers
closer or farther apart to emphasize it. THE END
Every recording is different from there.
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