Could you have wall mounted SDA's(other than the Soundbar)

okiepolkie

I've been bored lately and this came to mind. It has probably been hashed out here before, but I'd like to keep the same thread reoccurances like the RTi's vs LSi's have going

Could an on wall SDA speaker be made? With all of the wall mounted televisions, many companies are going to speakers that complement them. The SDA ones would not necessarily be for use with a flat panel tv, but I guess they could.

The enclosure could be somewhere between 15"-21" wide and maybe 3"-4" deep. Height could be varied, depending on the numbe of SDA drivers you wanted. They could be ported at the top, sides, or bottoms, or a passive radiator could be used.

I wouldn't expect the same type of bass response for these speakers, since they could not have the same internal dimensions. They could be mated with an appropriate subwoofer, in-wall or freestanding, to supplement the lower frequencies.

This design would be more WAF friendly and still allow us to have our SDA's. I know my wife has cringed every time I show her pictures.

I'm working on a couple of quick sketches(nothing elaborate). I'll post them when I get a chance.

Zach

VR3

How about some inwall SDAs?

I mean... it would compliment an inwall CC... considering it would be horizontally mounted...

They could make them with performance enclosure... could make some nice size enclosures that way...

okiepolkie

Yeah, the inwalls would be great too.

Since it doesn't look like Polk will do this any time soon, could you take a pair of CRS+'s, and make a modified enclosue that could fit in-wall or on-wall. If it were on wall, then the enclosure would have to be elongated to allow for the same internal dimensions, and placing the passive radiator facing out. They would look similar to the SDA 2's, but not quite as large. With the in-wall's you could have two separate grills-one for the drivers, and one for the PR.

This sounds like a fun project to me. Now who wants to send me a pair of beat of CRS+'s on the CHEAP

Larry Chanin

okiepolkie wrote:

I've been bored lately and this came to mind. It has probably been hashed out here before, but I'd like to keep the same thread reoccurances like the RTi's vs LSi's have going

Could an on wall SDA speaker be made? With all of the wall mounted televisions, many companies are going to speakers that complement them. The SDA ones would not necessarily be for use with a flat panel tv, but I guess they could.

The enclosure could be somewhere between 15"-21" wide and maybe 3"-4" deep. Height could be varied, depending on the numbe of SDA drivers you wanted. They could be ported at the top, sides, or bottoms, or a passive radiator could be used.

I wouldn't expect the same type of bass response for these speakers, since they could not have the same internal dimensions. They could be mated with an appropriate subwoofer, in-wall or freestanding, to supplement the lower frequencies.

This design would be more WAF friendly and still allow us to have our SDA's. I know my wife has cringed every time I show her pictures.

I'm working on a couple of quick sketches(nothing elaborate). I'll post them when I get a chance.

Zach

Hi Zach,

With enough determination you could always mount some SDA-CRS+s suspended from the ceiling near a wall.




In this application WAF is not a factor since it's hidden behind transparent fabric.

Seriously, I think the smallest width cabinet for an SDA type speaker was about 16-1/2" for the SDA-1 series. (The width of the CRS's were 20".) The SDA effect requires the spacing between the stereo and SDA drivers to be a head's width, so any SDA design has to be fairly wide. Anyway, if the width could be reduced to 14-1/2", perhaps by staggering the driver arrangement a little, it would be possible to build an In-Wall SDA. This would have the highest WAF of any SDA, short of what I have done... hiding them entirely behind a false wall. :cool:

Using the modern drivers from from the LC265i In-Walls and mating it with newly designed Performance Enclosures, could produce excellent In-Wall SDAs that should go down to about 40 Hz. Of course a supplementary subwoofer wouldn't hurt either.

EDIT: Sorry guys. I started this response and was called a way before I was finished. I didn't get a chance to read your responses until I posted mine. Great minds work alike.

Larry

okiepolkie

It would take twice the effort, but you could put the stereo drivers between two studs and the sda drivers could be between the next two studs.

The 3.1TL's are 15.75" wide, so if you did a little finagling, you could get all of the drivers between two studs. Looking at the pictures, you have at least 1" to work with from the outside of the driver to the outside edge of the cabinet.

Larry, do you happen to know the actual distances between the drivers in your CRS's, or even the 1C's?

When I originally thought of this topic, I was imagining the 3.5" drivers, like the ones in the surround bar, being used in this application. The cabinet would have to be wide, but not necessarily deep. The surround bar is 5.25" deep, so the on-wall versions could be manufactured at the same depth.

Larry Chanin

okiepolkie wrote:

It would take twice the effort, but you could put the stereo drivers between two studs and the sda drivers could be between the next two studs.

The 3.1TL's are 15.75" wide, so if you did a little finagling, you could get all of the drivers between two studs. Looking at the pictures, you have at least 1" to work with from the outside of the driver to the outside edge of the cabinet.

Larry, do you happen to know the actual distances between the drivers in your CRS's, or even the 1C's?

When I originally thought of this topic, I was imagining the 3.5" drivers, like the ones in the surround bar, being used in this application. The cabinet would have to be wide, but not necessarily deep. The surround bar is 5.25" deep, so the on-wall versions could be manufactured at the same depth.

Hi Zach,

The spacing between the stereo and SDA driver on the CRS+'s is 10" center to center. For the 1C's it's 7". The 10" may be a little on the high side since it's supposed to be about a head's width. I suppose it depends on how fat a head one has.

I doubt it would be necessary to use two adjacent stud bays to pull off an In-Wall SDA. I don't believe there's any critical design issue that requires the stereo and SDA drivers to be precisely horizontal, so slightly staggering the drivers should work. Didn't Polk do that with the SRT's? Obviously going to smaller drivers would also solve the cabinet width problem, but it would sacrifice a bit of performance.

However, even if we consider two 6.5" drivers on 7" centers that gives us 13.5" from edge to edge, leaving a full inch to provide for the driver structure and speaker housing. (The speaker frame of course can be wider than 14.5".) Since the In-wall housings are made of thin metal or plastic, rather than thick MDF, one inch should be ample space even if the drivers were positioned horizontally.

Yes, the less than 4" depth required for an In-Wall speaker is not an issue so long as you eliminate the large passive drivers in vintage SDA designs and rely on large, flat supplementary performance enclosures. Polk was not in the habit of publishing the -3 dB frequency response of their vintage designs. However, Stereo Review measured the -5 dB response of SDA-1C's at 20 Hz to 18 kHz. From this we can roughly guess that they have a lower -3 dB response in the mid 30's. Since the modern LC265i's go down to about 40 Hz with the currect performance enclosures, in theory it would be possible to increase the height of the enclosures to duplicate the vintage bass response. However, today the more conventional approach would be to simply use subwoofers. For a totally concealed application, Polk has recently announced In-Wall and In-Ceiling subwoofers.

Larry