Corner-Horn Imaging FAQ

[steve]

It took me long enough to sign in to the new forum! Wow! Hardly enough energy left to post a reply!

That said..

What with all the (greatly appreciated) postings, has anyone set up their KHorns to the proper specs before trying anythig else i.e. long wall measurment X .618 equals short wall measument as stated in the Klipschorn manual?

That's the instructions I got with my 1982 KHorns...I certainly understand and appreciate all the info here, but I think PWK's starting points should be adhered to first!

Regards

Steve

[dubai2000]

I just discovered this thread a bit earlier today. Interesting read even if I didn't get all of it......but what was easy to try was something soft on top of the Khorns - two smallish rugs. To be honest, I didn't think it would make a difference - BUT it did. The tonal balance shifted towards the midrange (a bit) and three dimentionality of 'the stage' increased. There is now greater front-back perspective.....figure that. It's never too late to try something new.

Wolfram

[Chris A]

On 10/29/2013 at 3:53 AM, steve said:

What with all the (greatly appreciated) postings, has anyone set up their KHorns to the proper specs before trying anythig else i.e. long wall measurement X .618 equals short wall measurement as stated in the Klipschorn manual?

That's the instructions I got with my 1982 KHorns...I certainly understand and appreciate all the info here, but I think PWK's starting points should be adhered to first!

Regards

Steve

 

Here is a link to the PWK Dope from Hope article on room proportions, and here is a link to a much improved article from just a few years ago on that same subject.

 

PWK made three suggestions that are echoed in here (albeit a little more generalized and expanded in this thread):

 

1) Pay attention to room relative dimensions if you have a choice of room size and shape, and use room relative dimensions where the room modes don't pile up additively or destructively in multiple modes at the same frequencies. Nearly square or cubic rooms are particularly bad about these issues. Larger rooms work better than small ones.

 

2) Use the long wall in order to get further away from the speakers at your listening position. It turns out this is largely due to two factors:

a. to hear low frequencies better outside the nearfield 1/4 wavelength radius from each bass bin's lowest frequency octave, and

b. to avoid "driver convergence issues" with the Khorn due to time misalignment of its drivers.

If you triamp your Khorns and time align the drivers using an active digital crossover, you can walk up to the speaker much closer and still retain convergence of the sound image. Placing the speakers along a long wall moves the speakers further away from the listener to facilitate convergence due to distance alone.

 

3) Moving the speakers out further widens the soundstage image, thus adding the apparent source width. You can also do the same thing by moving your listening position closer to the corner-mounted speakers, but only if you first time align the drivers.

 

Chris

[Ski Bum]

The above is why I find the contradictions so great that no conclusions can be reached. Smile.

WMcD

This was quite some time ago, probably inspired by this thread, actually...I had two high output impedance amps, one for each channel. I kept one channel hooked up to the source, and removed the input from the other, so one channel was completely unable to be influenced by the other. Using a multimeter to the terminals, I measured about 1.3mv, which from the sound of things was just power supply hum. That's actually better than spec per the amp's manufacturer, probably the reason I recall the actual number. Next, I cranked the volume on both amps, let the one channel blare away, and measured the other channel. I noticed the disconnected channel exhibited higher, and variable, voltage. It wasn't much more than the baseline residual voltage, still in the single millivolt territory, but it was there, . It seems to be an example of measuring the so called "Carver effect"/back EMF, if crudely so. It was so loud in the room that I couldn't tell if there was any actual directly detectable sound coming from the "silent" channel.

Seems like anyone with separate amps and an old scope could do the same thing and actively watch their speaker microphoning away. I would think they would get the highest microphonics with a speaker with open terminals; even something like a tube amp with high output impedance would clamp down a lot compared to that, and a low output impedance amp would act more like shorted terminals. All audible effects would have to be way down in the signal.

So from that experience and general listening, I think the reverb effect is real, but very, very subtle. It's enough to help fool my easily fooled brain about the size of the acoustic space, but far less noticable than an actual reverb processing, which I've tried.

[Chris A]

I knew that it had to be subtle, since many folks aren't aware of the source of the "magic" and what that means. Apparently, it also isn't very prominent compared to most reverb units that really crank in the effect.

 

In my view, as long as you are aware that in small rooms with very efficient loudspeakers...read that as "horn-loaded"...high-output-Z amps have this effect to the extent of the coupling, but if you don't dislike the effect, then...

 

In my pursuits, however, I've been trying to go the other way: as accurate and clean from all types of distortion as I can get in order to hear what is actually on the recordings. That is my personal goal, but clearly that is a minority opinion around these circles.

[raburns]

Thank you all for the insights, very good thoughts and info. I will be studying the document and apply necessary improvements.

[Sancho Panza]

OLD Thread Warning!!!! Top so I may find later

[seti]

"But What About the Equipment/Racks, Architectural Details, and Speaker(s) Between by Corner Horns?"

Again, the most straightforward way to deal with this is to simply remove all objects between the speakers, leaving smooth wall. If this is not achievable, the alternatives are the same as above. I use absorption tiles on the side and top of my center Belle, on the masonry on each side of my fireplace, and a quilt-based cloth fabric on the mantlepiece to control these early reflections.

"But What About the Television Between My Speakers?"

This one is easy: place a temporary quilt, comforter, or acoustic absorption tiles in front of the screen when you listen in stereo music-only (i.e., no video) mode.

I remember reading this thread a while back but part of me has been in denial about it. I have a friend who builds custom horn systems for clients and is also an engineer. He mentioned that I may want to move my equipment rack and turntable setup from between my speakers and to the back wall. I was in denial then as well... My room is not large but is a good size 12ft H x 13.5ft W x 15.3ft L. The jubs are on the 13.5ft wall.

Since I don't have too many major tweaks to make that are affordable. I may as well consider this one now. I'll just need a couple runs of 25-30 ft 18 gauge speaker wire (biamped). My question is how big of an improvement can be made by removing my system rack and turntable setup from between my speakers?

[bracurrie]

My question is how big of an improvement can be made by removing my system rack and turntable setup from between my speakers?

Let me share my experience. I had my Jub clones positioned equidistant from each other and the side wall with nothing between. No joy on imaging.

Placed them in the corners with the Eliptrac horns pointing just behind my head in my listening position with nothing in between and I ended up with a big hole in the middle.

I then implemented a quick and dirty middle channel using a forte II elevated to put the squawker and tweeter to equal height wit the Eliptrac. Lo and behold on a good many recordings the imaging was wide and deep with vocals in the middle when it was mixed that way. One day I received a phone call that distracted me when I was turning everything on and I forgot to turn on the center channel. Listening to Alison Krauss I was grooving on her voice appearing in the middle and the center wasn't even on as I discovered later.

So then I removed the Forte II and the hole in the middle again reappeared. I then put down another rug extending all the way to the back wall between the speakers and turned the Eliptrac on a 45 degree angle like the Jub clones. Again with no objects in between the hole was still there but it was way better. A mono mix appeared in the middle, but Alison Krauss was still diffused left and right.

So then I took an under counter fridge I pulled from my counter and placed it on the back wall in the middle because I had no other easy place to put it. Sat down with a long legal document I needed to review and discovered the hole in the middle was gone.

Then working to improve bass response with the integration of a sub woofer I discovered that a near field listening position worked best for the room. I am now equidistant from each speaker with the horns pointing directly at me and wow can I perceive depth as well as left right if the music was recorded and mixed right. Remove the fridge and the hole reappeared but to a lesser extent than from my old non near field listening position.

I believe but am not qualified to opine that reflections are where the magic occurs or is killed when it comes to imaging. If you can try it make sure you have reference material from which to make your comparison and make sure the floor between the speakers along the back wall aren't super reflective.

Enjoy!

[ka7niq]

On 11/2/2011 at 11:55 AM, Chris A said:

 

 

"So What's The Issue With the K-400 Horn and K-Horn Imaging In-Room?"

 

This "collapsing polar" characteristic means that the K-400 horn actually begins to lose polar control of its output frequencies in the vertical axis below about 1.7 KHz - down to its design crossover frequency of 400 Hz with the Khorn bass bin. This energy winds up on your ceiling and floor as 400-1700 Hz band-passed "extra early reflections". If your room has good carpet and high ceilings, the effect of this extra spilled-bandpassed energy on imaging is to impart a timbre shift in the sound of the Khorn. At worst, with low ceilings or hard uncovered flooring, it becomes a tonally imbalanced speaker.

 

The remedy to this "spilled energy" issue is to have high ceiling and carpeted floors. If you don't have high ceilings (i.e., at least 9 feet or 2.7 meters), then it is recommended to either put acoustic absorption material around the top and bottom of the mouth of the K-400 horn (like the Peavey QT horn) or to place diffusers or even absorption tiles on the ceiling. This would be especially true for basement-located Khorns with low ceilings.

 

Peavey QT Horn

 

"

I have low 6.5 inch ceilings, and a Tile Floor, so what do I do to the  Midrange Horn in my La Scala's, and what material shall I use ? How far back into the horn shall the sound material go ?

[Emile]

3 minutes ago, ka7niq said:

I have low 6.5 inch ceilings

Jeez; you have to "crawl" in your space? How do you place speakers in it?

Cheers, Emile

[ka7niq]

1 hour ago, Emile said:

Jeez; you have to "crawl" in your space? How do you place speakers in it?

Cheers, Emile

6.5 feet

[Chris A]

1 hour ago, ka7niq said:

I have low 6.5 inch ceilings, and a Tile Floor, so what do I do to the  Midrange Horn in my La Scala's, and what material shall I use ? How far back into the horn shall the sound material go ?

 

The material only needs to cover the edge of the mouth itself as it terminates into the mouth flange.  Having a little extra material around the flange will help, too.  The material can be anything thick, dense, and fuzzy.  I use Auralex Sonofiber material (basically it's made from compressed laundry lint). 

 

La Scalas have the forgiving characteristic of having the midrange horn closer to the floor than the other two corner horns (Khorns, Jubs) so for low ceiling rooms, adding absorption on the floor in front (at least 3-4 feet depth) and fuzzy material across the entire top of the top hats of the La Scalas will help. 

 

You can try out absorption on the side and front walls closest to the midrange horn mouths, and perhaps an inch of absorption (or thicker if using diffusion devices instead) on the ceiling at the first bounce point to listen to the effects (fuzzy blankets will work temporarily to hear the difference).  If it's worth it in terms of sound quality, then you'll know what to do.

 

Chris

[ka7niq]

9 minutes ago, Chris A said:

 

The material only needs to cover the edge of the mouth itself as it terminates into the mouth flange.  Having a little extra material around the flange will help, too.  The material can be anything thick, dense, and fuzzy.  I use Auralex Sonofiber material (basically it's made from compressed laundry lint). 

 

La Scalas have the forgiving characteristic of having the midrange horn closer to the floor than the other two corner horns (Khorns, Jubs) so for low ceiling rooms, adding absorption on the floor in front (at least 3-4 feet depth) and fuzzy material across the entire top of the top hats of the La Scalas will help. 

 

You can try out absorption on the side and front walls closest to the midrange horn mouths, and perhaps an inch of absorption (or thicker if using diffusion devices instead) on the ceiling at the first bounce point to listen to the effects (fuzzy blankets will work temporarily to hear the difference).  If it's worth it in terms of sound quality, then you'll know what to do.

 

Chris

Here are my LaScala's in my room corners, and yes, those are 4 ft tall bass traps next to them on one side, and diffusors on the other 

Sorry about pic quality

[ka7niq]

My LaSacala's are sounding very very good, in the corners. If you look in the pictures right above this post, you can see the 4 ft tall bass traps, almost right next to them. The bass traps went in my corners, but when I placed  my speakers there, it made my bass traps homeless  

So, I placed the bass traps next to my speakers, mostly because I was too lazy at that time, to move them out of the room.

 

It is said that sometimes, even a blind Pig will find Corn, and I have found my Corn, because the LaScala's sound wonderful, in my room corners.

And, wonder of wonders, they are imaging very well, to my surprise! 

 

The big Apogee SA 800 B amp has also been a complete and total surprise. Since the big amplifier from California has been hooked up to the LaScala's, it has remained undefeated. I do have a few more amps to try, but at this moment, I am just enjoying the LaScala's, and looking for Klipschorns.