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Cornwall in a small room..running 2.0 ??


Northman

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We are building a house, and I have sort of gotten a OK of transforming a gust room to a AV room. Sort of.. its supposed to be used for guests and home office occasionally, so I can´t go full AV.

 

The room is, 11.5 ft x 16.5 ft., with a long slender window above the speakers and 6ft window on the oppsing wall, aswell as a glass door. I am putting heavy drapes across them.

 

Running Cornwalls, in such a small room, in a 2.0 system, would I be missing out on the surrond experience? Or would their massive soundstage kind of neglect it?

 

The TV will be a 75" ULTRA HD 4k, running the new Oppo ( when it releases) sitting 6-7ft away from it and the speakers.

 

Skjermbilde 2017-03-30 kl. 13.52.59.png

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6 hours ago, Northman said:

The room is, 11.5 ft x 16.5 ft., with a long slender window above the speakers and 6 ft. window on the opposing wall as well as a glass door. I am putting heavy drapes across them...Running Cornwalls in such a small room in a 2.0 system, would I be missing out on the surround experience? Or would their massive soundstage kind of neglect it?

You'd miss out on the "immersive experience" in that size of room with few reflections having longer delay times would be present. The deal with small rooms is to get enough surround channels to experience the longer time delays, thus making the room feel much larger during movies and surround sound music.    Your idea for three more Cornwalls is a good one, especially if you can find a "vertical Cornwall" than can lie flat under the screen.

 

The use of a HT center channel is usually an issue with speech intelligibility in your case.  If you only have one couch sitting centered between the corners of the room and on axis with the TV, the issue of locking in the center image is not a big deal.

 

I'd certainly not be shy about placing a more absorption at the front of the room around the TV and make sure that any other acoustically reflective objects in the middle are minimized in order to retain a good center image without having to resort to not toeing in your Cornwalls properly (I'd recommend toeing them in more than you show in the picture).  Reflective objects between your speakers will kill the center imaging. 

 

If you can, think about placing the electronics to the side of the room on one side down low or not more than 12 inches high off the floor if centered under the TV.  Covering the sides of the electronics boxes and stands with acoustically absorbing material would help greatly in regaining the center imaging.  Placing absorption panels or squares on the side walls just at the height of the Cornwall tweeters will also improve imaging a great deal.  For determining how much absorption is needed, you can do all the absorption placement cheaply by pinning up blankets or quilts and having a listen.  This will help you decide on the amount of absorption that will minimize early reflections around the front of the room that will kill your soundstage. 

 

I'd also recommend keeping your Cornwalls within a foot or so of the corners in order to avoid 200-300 Hz frequency response suck-outs and also avoid loss of deep bass response from the Cornwalls.  Using absorption on the side and front walls to control early midrange reflections will give you all your imaging back without killing off your midbass and low bass response from pulling them out of the corners.

 

Chris

 

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11 hours ago, Chris A said:

You'd miss out on the "immersive experience" in that size of room with few reflections having longer delay times would be present. The deal with small rooms is to get enough surround channels to experience the longer time delays, thus making the room feel much larger during movies and surround sound music.    Your idea for three more Cornwalls is a good one, especially if you can find a "vertical Cornwall" than can lie flat under the screen.

 

The use of a HT center channel is usually an issue with speech intelligibility in your case.  If you only have one couch sitting centered between the corners of the room and on axis with the TV, the issue of locking in the center image is not a big deal.

 

I'd certainly not be shy about placing a more absorption at the front of the room around the TV and make sure that any other acoustically reflective objects in the middle are minimized in order to retain a good center image without having to resort to not toeing in your Cornwalls properly (I'd recommend toeing them in more than you show in the picture).  Reflective objects between your speakers will kill the center imaging. 

 

If you can, think about placing the electronics to the side of the room on one side down low or not more than 12 inches high off the floor if centered under the TV.  Covering the sides of the electronics boxes and stands with acoustically absorbing material would help greatly in regaining the center imaging.  Placing absorption panels or squares on the side walls just at the height of the Cornwall tweeters will also improve imaging a great deal.  For determining how much absorption is needed, you can do all the absorption placement cheaply by pinning up blankets or quilts and having a listen.  This will help you decide on the amount of absorption that will minimize early reflections around the front of the room that will kill your soundstage. 

 

I'd also recommend keeping your Cornwalls within a foot or so of the corners in order to avoid 200-300 Hz frequency response suck-outs and also avoid loss of deep bass response from the Cornwalls.  Using absorption on the side and front walls to control early midrange reflections will give you all your imaging back without killing off your midbass and low bass response from pulling them out of the corners.

 

Chris

 

Why you wanna toe in more than 45 degrees? That seems strange to me 

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5 hours ago, Scrappydue said:

Why you wanna toe in more than 45 degrees? That seems strange to me 

You quoted a lot of text, above, to reference one sentence fragment...:blink:

 

Your answer: http://www.libinst.com/PublicArticles/Setup of WG Speakers.pdf

 

Chris

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I see.  I don't use a phone to use websites.  It saves the budget about $100/month, thus providing neutral funding for my old CD buying habit for demastering ripped music tracks and other audio goodies.

 

Can you open that linked article, above?

 

Chris

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I've found a lot of really bad information on the web and elsewhere when it comes to directional loudspeakers...most of it, in fact.  The people referenced at the bottom of that article are some of those that seem to know a lot more of the subject that they're talking about.  (I'd add Roy to that list--but it's a short list, indeed.)

 

For me, "high end" is synonymous with "doesn't really understand...but keeps up with the most recent audiophile memes". 

 

YMMV.

 

Chris

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It's good to disseminate good information.  :emotion-21:

 

Note the important condition of "minimizing nearfield acoustic reflectors between the loudspeakers in the front".  Most people tend to forget that, or otherwise don't believe it.  It's real, trust me.

 

Chris

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Yes. Anything with flat acoustically reflective surfaces--either at the loudspeakers or near the prime listening position(s).   Move them away by at least 4 feet. 

 

If you've got diffusion panels, make sure that they're good down to 300 Hz: most diffusion panels don't do very well in that regard (the requirements wind up producing too thick panels).  I really don't recommend nearfield diffusion based on the best information that I have now, but rather nearfield absorption.  Preserving the phase of higher frequency harmonics is essential for clarity of presentation.  But that's another subject...

 

Chris

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That includes high-backed listening chairs, BTW.  I use thick absorption on the headrests--folded up small fuzzy blankets.

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That's a good article Chris, thanks.  When you ask 10 Klipsch owners about toe-in, you get 20-30 different answers, but I think most fall into a range from "they cross a little bit behind my listening position" to "they cross a little bit in front of my listening position."  A lot depends on room geometry and distance from the speakers.  I wonder if it also depends on the horn itself?

 

For example, if I toe-in my La Scala II's too much, and then sit in position "O" on the outside right of my listening position as the article shows, I can hear the more-distant left-hand K401 horn beaming directly at me much louder than the closer right-hand squawker at an oblique angle.  REW measurements confirm this.  If I back-off the toe-in a bit so that "they cross a little bit in front of my listening position" the sound stage is much more consistent without the "head in a vise" deal.  Somebody with a tractrix horn might have a different experience?

 

There must be a way to represent this with math that's beyond me, but my theory with the K401 is, regardless if you prefer them crossed in front or behind you, when one horn is pointed at you, the other horn shouldn't be too far off.  I'm guessing Northman's experience with the Cornwalls would be similar.

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On 4/1/2017 at 7:38 AM, Chris A said:

Yes. Anything with flat acoustically reflective surfaces--either at the loudspeakers or near the prime listening position(s).   Move them away by at least 4 feet. 

 

If you've got diffusion panels, make sure that they're good down to 300 Hz: most diffusion panels don't do very well in that regard (the requirements wind up producing too thick panels).  I really don't recommend nearfield diffusion based on the best information that I have now, but rather nearfield absorption.  Preserving the phase of higher frequency harmonics is essential for clarity of presentation.  But that's another subject...

 

Chris

I agree, absorbing the primary reflection points is a significant improvement in clarity and sound stage. I found the best way to do it is to have a friend sit on a couch or get a balloon and place it in the middle seat where your head would be when listening. Then have another buddy take a laser pointer and put it on top of the speaker on the front edge. Get a small mirror and place it on the wall at the same height as the person sitting (or balloon). Start right next to the speaker and have your buddy shine the laser on the mirror. Slowly move along the wall until the reflected laser hits the person in the chair or the balloon. That will be the reflection point that needs to be absorbed. Do this for each speaker and each wall so you will have a total of 4 points, 2 on each side between your speakers and the listening position. 

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1 hour ago, pbphoto said:

 I wonder if it also depends on the horn itself?  For example, if I toe-in my La Scala II's too much, and then sit in position "O" on the outside right of my listening position as the article shows, I can hear the more-distant left-hand K401 horn beaming directly at me much louder than the closer right-hand squawker at an oblique angle.  REW measurements confirm this.  If I back-off the toe-in a bit so that "they cross a little bit in front of my listening position" the sound stage is much more consistent without the "head in a vise" deal.  Somebody with a tractrix horn might have a different experience?

Yes.  The K-600, like the K-400 in the Khorn and La Scala and the K-500 in the Belle, clearly have a narrower coverage at higher frequencies, etc.in both horizontal and vertical directions. I've not seen a polar coverage plot of any of these horns, but they are also noted for their "collapsing polar" characteristic in the vertical direction.

 

As you toe in your Cornwalls more than the on-axis point, you will hear less and less more-or-less gradually  This is unlike the K-402, which has solid coverage out to 40-45 degrees horizontally, then drops off in loudness at greater off-axis angles pretty rapidly.  So the toe-in trick doesn't work as well for the K-402 as the K-600. 

 

Chris

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In a room that small, there is no use for diffusion at all.  It will not work in that small space.

 

Absorption is the key and likely a significant amount.  The back wall and side walls will reflect massively and there will be SBIR from the fronts in those corners.  A small room can be a great room, but there is no way it will sound good without absorption and a significant amount.  

 

I would also caution that the waveguides of the conrwalls are not like the SEOS 12, SEOS 15 and SEOS 18, I am not sure that crossing them past 45 degrees will make for the sound that you want.  That can only be determined by testing.    It would appear from a picture of a conrwall that maybe the midrange would have the directivity but definitely not the tweeter.  

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