K Horn Optimum Room Size

[Brockybear]

Hi

I am building a new extension to my home - 2600 Square feet. It will be open plan living area but I want to provide an area for my stereo and wonder if there is an optimum room size for the K Horns ?

[Groomlakearea51]

From what I understand, as long as it's not "square", and is more or less the "golden rule" in terms of dimensional ratios. Others on the forum, especially MAS and Dr. Who may have some thoughts on size and dimensional ratios. I have found that the K'horns sound best on the long axis of the room.

[DrWho]

The khorn is an interesting speaker that I have found to be extremely

dependant on the room. And though it kinda goes against typical

acoustic principals, the best room I've heard them in has also been the

smallest...

I guess the real question is what are you hoping to achieve? Do you have full reign over the shape and size of this room?

The absolute best thing you could do for your room is splay the walls.

I'm yet to see anyone on this forum do it, but it is absolutely the way

to go. It's a bit more difficult to do with khorns because they require

corners, but that's just a design point that is easy to work around.

If you can't do splayed walls, then you're simply going to need more acoustical treatment. You might also consider 3-channel stereo if your room starts getting a bit large too.

What kind of music do you listen to?

[Groomlakearea51]

Yes, I agree - splayed if possible. I've got a "splayed" ceiling in the 200 sq ft room we are enclosing for a pair of K'horns, and am also looking at a slight wall "splay" starting about 18"-24" out from the outer corners of the K'horns. Won't be much, maybe 8" down to 4" over a distance of 12'. Just enough, maybe, to have some positive effect. It's obviously a small room I'm dealing with so I may not be able to really notice it when we get finished. Treatment should not be overlooked at all; you might want to read some of the threads in the architectural forum section before you start.

[colterphoto1]

My experience shows that most Khorn lovers who consider their rooms ideal are listening from a position where they are back from the front wall a distance of .7- .8 x the width of front wall. If the spread of the speakers is too great an electrical third channel utilizing a LaScala or Cornwall is generally called for.

I'll start getting room dimensions from callers as well. My room is 20 x 15 with Khorns on long wall. With today's modern homes and huge rooms my experience is that many people are sitting much too far back and would do best to be on the front edge of where their coffee table now stands.

The 60th anniversary takes a lot of this out of the equation because the integral built-in backs allow the speakers to be splayed outwards so the seating area can be a more comfortable distance or the narrow wall can be used for speaker placement.

[ByteWrangler]

The Golden Ratio, BTW, is determined by

X / Y = (Y / X) + 1

which works out to about 1.6 : 1. Practical-sized rectangular rooms with dimensions near Golden Proportions could be approximately

8' X 13' X 20' 6"

9' X 15' X 23'

10' X 16' X 25' 6"

Even if those dimensions won't work for you, they may give you an idea. Mine are on the short wall of a roughly 15' X 27' room with 9' ceiling. It has plaster walls (sheetrock ceiling) and hardwood floor mostly covered with rugs, couch and loveseat, large windows and French doors with sheer curtains (usually closed) and various wood bookcases and pieces of furniture, and no specialized room treatments. Driven with 50 W/ch, they sound great; even playing LOUD the amp stays cool, so it's not working very hard!

[DrWho]

If you're forced to deal with a rectangular room, you want to pick dimensions such that you have a dense, but equally spaced modal distribution with the intent of preventing overlapping problem frequencies (which then become harder to deal with). I'm not sure if a golden ratio ensures that or not, but I would probably rely more heavily on some of the free modal prediction software to determine ideal dimensions for the scenario.

[greg928gts]

I too built a room for my Khorns many years ago. One of the mistakes I made was to locate my large screen tv in the middle of the long wall that the Khorns are on. The large cabinet between the speakers affects the imaging of the sound. Bookcases or furniture on the side walls will impact the impact as well.

So my advice to you, in addition to what has already been mentioned here, is to minimize the amount of stuff on the walls between the speakers and on the side walls for a distance away from the speakers.

Also, make accommodations for a center channel speaker like a Belle. You will be glad you did later on.

Greg

[Brockybear]

Thanks everyone for the advise. I will be meeting with the architect next week and will take along your suggestions

[JJkizak]

You might want to design in some nice sized wire troughs that will hold your future 10,000 billion wires that will accummalete over time.

JJK

[Islander]

According to the Heritage manual/leaflet, Klipschorns need a ceiling height of at least 8.5 feet, because of the height of their tweeters.

[mas]

Just a few comments....

Ceiling heights, etc., are only a factor in that the polar dispersion of the mid and high freq horns may induce first order reflections.

Magic dimensions are only useful in trying to evenly distribute room modes/standing wave peaks. Few have the ability to design such rooms to such specs, and measurements and bass traps can be used to mitigate this. Also, such calculations become moot if the room is not a perfect (as in IDEAL) rectangle. Guidelines and calculators are fun, and can gie you a very rough idea, but simply cut to the chase and measure and address the real space.

Splaying the side walls and ceiling ~12-14 degrees (meaning 6-7 degrees for each side wall) can minimize these. Highly recommended if possible.

As far as the placement of 'stuff' on the side and front walls, the low frequencies will not see much of what is placed there simply due to the nature of the size of the wavelength (upper bound) relative to the object. So keep this in mind. The front wall will most likely have little effect on first order reflections from the mid and high horns due to their Q and polar patterns (assuming corner placement).

But to go beyond this, the focus should still be addressing room modes with bass traps (corner traps and surgically tuned and placed Helmholtz resonators, if necessary), building a defined initial signal delay gap (ISD/ITD) by SURGICALLY removing (absorbing) early arriving first order reflections arriving within ~20ms, and then diffusing the heck out of the remaining reflects in order to create a rich diffuse semi-reverberant space by which to add a sense of largeness to the small acoustical space.

[DrWho]

You make it sound so easy Mark []

[Islander]

It is easy when you have an acoustic scalpel for surgical audio trimming. []

[mas]

The concepts are easy to understand.

With experience (working with measurements), one can estimate 90% of the required applications and their gross placement in 'simple' rooms.

Measurements provide for the specifics that allow for the surgical application of absorption and the verification and proof of performance.

One wonders, how many of you would design one of the so common expensive passive crossovers without parts measurements/values and by simply looking at the external appearance of the (unknown value) components and without knowing the measured characteristics of the various component drivers?

But how many of you who would laugh at the notion of building a crossover using generic unknown value components think that room measurements aren't necessary?

[dbflash]

"Splaying the side walls and ceiling ~12-14 degrees (meaning 6-7 degrees

for each side wall) can minimize these. Highly recommended if possible."

I'm sorry for being stupid, but i was born that way. What exactly do you mean by splaying the walls and ceiling. next spring i hope to gut my 2 channel room and redo it and i'm trying to get some ideas.

thanks,

danny

[mas]

...Not a stupid question at all...I wonder how many others are benefiting from your asking!

Splaying the walls (and/or ceilng) involves building them so that they are wider (higher for ceilings) at the back of the room than at the front.

[DrWho]

Kinda like an amphitheater (but not as dramatic). The goal is two-fold: non-parallel walls won't have flutter echo and then the angles help you push the early reflections away from the listening position.

[WMcD]

You can read PWKs thoughts on this.

I don't have much faith in the calculations because they appear to be based on the assumption there are no doors, no pass-throughs, no hallways, etc. Almost a hermetically sealed room.

I suspect that any real room is either not as good as predicted or not as bad as predicted because of the hallways, open doors, etc. Maybe that is why PWK was finding rooms to be good even though they depart from the ideal values.

Gil

DFH on Rooms.pdf

[mas]

Gil,

All of the various room mode calculators are limited. Rooms are assumed to be ideal. Any variation imposes great non;linear overhead for which even EASE, with its parametric based room models, has problems.

While the calculators can give you a rough idea (think of them as audio's video games), the easiest and most accurate method is to simply measure what the real resultant characteristics are, rather than to use limited prediction tools.based upon ideal assumptions.

Trying to guess what things should be is fun, but measuring the actual room is always easier.

One easy guideline to follow in order to minimize the coincident summing of modes is to avoid dimensions which are multiples of each other, or that feature multiple common denominators.

Hence, for example, I would anticipate additional modal problems in an 8 x 16 x 24 or an 8 x 12 x 16 room.

But regardless of the dimensions, you WILL have room modes that should be addressed. You are not going to magically avoid them regardless of the dimensions. The optimal dimensions will simply minimize the reinforcement via summing of various modes (resonances where the signal persists in time) due to their coincident summing at certain spots at certain frequencies.

And again, the best way to proceed is to minimize predictably bad dimensions (common multiples) and ultimately to measure the room and address the modes with bass traps.