open or closed

[smithski]

I just purchased a pair of Klipsch PRO 4650 60W 2-Way In-Wall Home Audio Speakers. I couldn't pass them up for the price. I would like to build a speaker box for them instead of installing in the wall. Question is, should I leave the back of the speaker box open or close it??

[derrickdj1]

Are you putting them in a wall?  If yes, they are design to work in the wall.  The wall open space is the box.  Also, welcome to the forum.

[Chris A]

22 hours ago, smithski said:

I would like to build a speaker box for them instead of installing in the wall. Question is, should I leave the back of the speaker box open or close it??

If you're trying to get the most out of the low frequencies, then the following chart can be used to determine the size of a flat board (i.e., "open baffle" or "OB") that you can use.  Note that the specifications of your loudspeakers indicate that they go down to 75 Hz (i.e., a -3 dB point is assumed):

 

 

(from: https://web.archive.org/web/20080310035341/http://melhuish.org/audio/baffle.html)

 

Otherwise, you'd have to build a fairly good sized closed box in order to not significantly raise the open-air bass resonance frequency.

 

There are also open-back boxes that use the same principle as an open baffle.  The idea is that the shortest length to the listener's ears of that back wave woofer is the same as the open baffle case.

 

Chris

[smithski]

Thanks for your replies guys, I have decided to go open baffle.

[JohnA]

There is an optimum box size, ported and sealed, based on the parameters of the woofer.  You may be able to get the Theil-Small parameters from Klipsch, or you can buy a Woofer Tester and get your own.  You can use BassBox to calculate the box of your choice.  You can also do it by hand, but a program is too much easier. 

[CECAA850]

12 minutes ago, John Albright said:

You may be able to get the Theil-Small parameters from Klipsch

I don't think I've ever seen T/S numbers on any of Klipschs drivers???  They may be out there somewhere but they're not forthcoming.

[Chris A]

That's why I posted the open baffle size graph above.  Doing a closed box will require more data from Klipsch that's apparently not available for that loudspeaker model...although it should be available for those potential customers wanting to do the same thing. 

 

(I also don't sense that the OP is into doing science projects either: KISS seems to be the order of the day.)

 

Chris

 

 

[WMcD]

This indicates it wants a (closed) box of 850 cubic inches. I'd go with that.

 

http://images.klipsch.com/PRO-4650-C_-_Spec_Sheet_635727471341970000.pdf

 

WMcD

[Marvel]

I was thinking it would be a rather small box, since it is designed for a wall cavity.

[WMcD]

I was thinking a box with a front the size of 8,5 x 11 paper and 10 inches deep.  Some adjustments therefor board thickness.  It is not really small for a six-inch driver. 

 

In the wall we'd have 3 inches deep and 16 inches or less between studs and then form a cavity 18 inches tall.

 

WMcD

[dtel]

I asked about box size years ago for some in-walls, they were cheaper models than yours and was told about 1.5 cubic feet which is close to the average in wall space used.

I guess by the time you move a little insulation that was the estimate ?

 

 

 

[smithski]

Thanks to all for the replies, I did see the spec of 850 CI.