False Korners vs. Real: Any difference?

[Mallette]

This has been discussed (and is now being discussed in another thread) but I would like the latest thinking. I rather like my setup, but as mentioned in that thread it is a bit small. While the sound is good, there is not a lot of room and I have a rather large family area I am thinking of kicking the kids out of. There is another area they can occupy.

This are has one corner but it open to a path/balcony overlooking the front door (typical US pleasantville two story). If I built a false corner for one of the 'horns, I could get about 16' X 24' of spacing and have significant room. 'horns on the 16' side.

Is there any real, audible difference in a false corner? Must it have a floor, or do you just need a nice, rigid 90 degrees?

Dave

[Duke Spinner]

yes, a Korner .. should have a Floor ...

[ZAKO]

A Korner without a floor is like a Korner with a trap door,,,, But there should not a difference !!!

[Brac]

I put a floor just caused it seemed like the easiest way to get some strength... but I guess you don't need one as long as you can keep it tight to the speaker at the bottom..

[greg928gts]

Yes, I think there is a difference, but if the false corner is very solid, and built large enough, I think the difference is very minor. Keep in mind that all rooms have differences from one side to another, usually. All rooms usually need some sort of treatment to be optimum. So the difference between a false corner and a real corner is probably not much more than having a stuffed chair on one side of the room and a glass case on the other.

Yes, you should always have a floor under your Khorns. []

Greg

[Mallette]

>So the difference between a false corner and a real corner is probably not much more than having a stuffed chair on one side of the room and a glass case on the other.

Hmm... That's significant. There is a rolling chair in my music room that I am constantly moving as it seems to impact the sound even when it is not in direct line. Of course, it might contain a small black hole...

[DrWho]

Any difference? I would expect far better performance from a properly constructed false corner. I would wager a lot more horns would be built out of drywall if it was actually an acoustically better material...

The reason for letting the room complete the flare on the khorn is purely logistical and economical...not a performance enhancement.

[Duke Spinner]

re: Floor ..

lets not forget what " Space " we are in

[Bill W.]

Dave,

A properly built false corner WILL make a real, audible difference. Years ago, I had a similar situation in a living room with good dimensions but only one solid corner. The other would- be corner was a pass- thru to the kitchen and dining area. There was nothing to prevent the bass from traveling into the kitchen, resulting in poor loading of the bass horn at low frequencies and anemic bass in the listening area, even though one khorn was in a solid corner. A false corner was constructed for the open area based on the DFH memo on false corners that Klipsch released in the late 70's. I built this as a double sided 3/4" plywood structure which was glued and srewed onto a 2x4 frame. As an added measure, this was sand filled to provide maximum low frequency performance. This room became on of my favorite listening rooms for the khorns as a result of the improvement.

Another experience involved the Klipsch retailer in Tucson AZ, also in the late 1970's. They had recently opened a second location that included sound demonstration rooms on two levels. The "high end" room was located upstairs on the second level with walls constructed of wood paneling over a wood frame. The Klipschorns that were installed there did not live up to their potential because the corners were acoustically porous. Even at moderate volumes, low and mid bass frquencies were heard outside the room where the corners were located. This combination of severe leakage and resonant wall materials resulted in a tubby mid-bass characteristic and a loss of solid fundamentals below about 80hz. This was the worst Klipschorn presentation at a dealer showroom I have heard in 35 years. I agreed to build a matching set of false corners for this room. After installation, we held an extensive listening session. The false corners solved the underlying problems to such a degree that this room became one of the better listening rooms for Klipschorns I have heard .

btw- there is no requirement to provide a bottom to the false corner as long as the existing floor is level and even, allowing for a good acoustic seal.

Bill

[Cut-Throat]

My wife was asking me this just the other day. I told her that I could definitely tell the difference between falsies and the real thing!

[Mallette]

>I built this as a double sided 3/4" plywood structure which was glued and srewed onto a 2x4 frame.

You put the sand in the base? Anybody else have a comment on this? I can see doing that if you have a hollow bottom, but I am wondering if simply useing a 1" solid base would not be close enough without going to that extra bit of trouble. My target room is carpeted, so I think a solid floor is required, but I am not sure I want another 5" added to the 'horn height.

I am getting intrigued. I may give this a shot in a couple of months. I am also considering building a gravel-filled base for my TT's. My shelves simply are not rigid enough.

Dave

[Bill W.]

Dave,

The reason I tried the sand - filled approach was that our room walls were constructed of fully grouted slump block. I wanted to try getting the same sound from each bass horn. It was probably overkill but it did work just fine.

Bill

[IndyKlipschFan]

FYI false backs will help a lot.. False corners will really do well as well.

But NOTHING, I repete NOTHING, will do better than a good room with your seats in the right place.

[Brac]

walls were constructed of fully grouted slump block

What is this?

[Bill W.]

Brac,

Slump block is a common building material in the Southwest. Basically a cast concrete block that is removed from its mold before it firmly sets up, allowing it to sag or slump, bulging in the middle. this gives them a slightly irregular appearance. Grouting is filling the voids of a block wall with a concrete slurry to increase its strength and load-bearing capacity.

[Guest BobG]

Bear in mind that the best placement for Klipschorns puts them in 1/8th space. That means a corner with walls that extend to infinity. OK, so your house is not infinitely large. The size of the corner determines how low in the bass you get effective 1/8th space reinforcement. If you want that down to say 30 Hz, you need corners that are ~35' in each dimension. Really small false corners help but it's not like corners with 10' sides made of acoustically opaque material.

[Mallette]

>Bear in mind that the best placement for Klipschorns puts them in 1/8th space.

1/8th of WHAT space?

>If you want that down to say 30 Hz, you need corners that are ~35' in each dimension.

You are kidding me. That means it is totally impractical to get real low bass (32' organ pipe) from a 'horn at a realistic level and makes a subwoofer not really optional to the organ lover.

Dave

[Deang]

http://www.trueaudio.com/st_spcs1.htm

With false corners, you still need the corners -- but you don't have to be in the corners, just within a foot of them.

[Mallette]

OK, I am still not entirely clear on this, but it seems that false corners are not going to do it, at least theoretically. I assume they must extend to cieling hieght and even then you are going to have one side under size (one side of the room I was considering is completely open).

OTOH, I've learned that, when I build my new house in a few years, I need to spec rigid corners where the 'horns are going to be from floor to cieling.

A bit dissapointing, as the PAW had fully bought in (!) and I was beginning to like the idea.

Dave

PS - This is also a bit disappointing in general. I originally understood from PWK's mouth that, properly seated in a normal corner of the average room, the K'horn design am was to extend response to 32hz. Recent comments cast doubt on this.

[Bill W.]

Dave,

Bob G. meant 35 inches in each direction, not feet.