Urei 813 separation

[mgphoto]

I'm getting ready to build a tracking and mix down room with a pair of Urei 813s and Bryston amps. The speakers will be in soffits.

Can any one recommend the minimum distance of separation of the two speakers or any a link to any technical paper with similar information?

[Robh3606]

Try here. The manuals for the series are on the JBL site.

http://www.jblproservice.com/navigation/Vintage%20JBL-UREI%20Electronics.html

Rob:)

[mgphoto]

Thanks for the reply. Those are pdf for general information on the unit itself but nothing on the minimum suggested seperation distance.

[johnaec]

A general rule of thumb is to put the speakers at 2 corners of an equilateral triangle, with listening position at the 3rd corner, so the farther from the speakers you get, the wider they should be. Another way to say it is that the distance between speakers is the same as from a speaker to the listening position.

John

[Robh3606]

Those are pdf for general information on the unit itself but nothing on the minimum suggested seperation distance.

Well this is right out of the C version users manual that is right on the page I posted. This fall's right in line with what John has posted as well.

Rob:blink:

[doodlebug]

That formula has worked pretty well for my 813As - and for the other speakers I've used, too. Seems to me that this is also refered to as the Cardas setup, although I'm sure he didn't invent it.

Cheers,

David

[mgphoto]

Thanks guys. I have a fundamental understanding of the "triangle" and other things. I've been an engineer for 20 years and I worked at Westlake and Neve for a number of years.

That being said, any stereo speaker system has a minimum distance of separation before you start getting to a proper stereo image. Granted much of that is based upon environment, but most manufactures have a separation point that they believe is ideal for their system. I'm trying to find that distance point for the 813s.

[Robh3606]

That being said, any stereo speaker system has a minimum distance of separation before you start getting to a proper stereo image. Granted much of that is based upon environment, but most manufactures have a separation point that they believe is ideal for their system. I'm trying to find that distance point for the 813s.

OK but these are essentially point sources for the duplex drivers. I can understand that on a conventional multi-driver system where you need a minimum distance from the speaker to get good driver integration. The key to them is to have that horn aimed right at your listening position. It simply may not be an issue in the listening distances typical in a studio set-up.

The only place I have seen a minimum distance listed is in the 4350 Operators Manual however it may be in others. It would be nice if any of the larger monitor owners that have the set-up instructions in there manuals please share them here.

Rob:)

[mgphoto]

Yes, any help from anyone with direct experience on this issue would be appreciated.

I can build the room to any needed dimension but obviously one of the most critical set of dimension is the relationships of speaker to speaker and speaker to the mix position so I'd like to start with that number and go from there.

[Bob Womack]

Hi! I am also an engineer and have spent the last 20 years with 813b/cs as my "home" system. The room where I've worked the most (where I'm currently sitting) is an unlicensed LEDE room built in 1996 with 813b/cs.


http://www.in2guitar.com/stereo/813ssis.jpg


I don't have the blueprints for the room handy or a tape measure, but I used my 12" long clods to measure for you. Center to center (cabinet center), I measure approximately 10 feet and the setback to the mix position is 10 feet as well. This room has excellent stereo imaging with a strong center but very good spread and a well-defined field between center and driver.

Before we built this room, we used the 813s on pedestals and were able to move them back and forth. As I remember, at anything below about 8 feet on center, the mix began to collapse to the center and you lost some of the spread.

As it happens, I have a pair of 811s at home that are set with approximately 10' spread on center forced by the 8' entertainment center they flank. Setback is 10 feet.


http://www.in2guitar.com/stereo/stack.jpg


Though they aren't in a soffit, I'm getting an excellent sound field between them with a well-defined center and a nice spread.

Hope this helps a bit.

Bob

[Mr. Widget]

As it happens, I have a pair of 811s at home that are set with approximately 10' spread on center forced by the 8' entertainment center they flank. Setback is 10 feet.In my rather large listening room using large playback monitors of a different type, I have also come to an ideal of a 9 to 10 foot equilateral triangle. I came to this arrangement after having tried a wide range of listening and speaker positions.


Widget