Wall mount speaker build and help

[icetraxx]

Can someone point me to a guide to build a set of wall mount LCR speakers. I am looking for a design similar to atlantic technologies fs3200 series (long and thin 6in wide, 5-6in deep, and 36" long) The LR and center are going next to a 52" lcd that is mounted on the wall.

I am pretty much stuck as to what I speakers I would use also. Tweeter is certain, however I am unsure if I need just mids or woofers or both to give me my mid range with some lows. A sub will be next on my list.

The receiver that they will be connected to will be a denon 789.

I am new to all of this but I am a avid do-it-yourself type that has the tools for a project like this and want to give it a try.

Thanks,
Larry

[ThomasW]

It's a little more complicated than one might imagine....this should get you started...

http://www.rjbaudio.com/Audiofiles/FRDtools.html

[impulse]

Hi Larry.

I am actually on the look for the same setup as you. It seems there are few if any DIY builds that cover this design criteria (wall-mounted, depth of 5-6 inch). I've just finished the Bose Buster but they didn't do it for me. The tweeter sound a bit harsh, and little or no bass. The main problem is power handling. Even with active crossover to sub at 150Hz they reach X-max quickly. They work well in very small rooms, but in my livingroom (17 x 17 ft) the sound is to lean.

What you are looking for is a design with some x-over options. When placing a convetional speakerdesign up against the wall the x-over normally don't need BSC (or at least less BSC then stand-mounted).

I am now thinking in terms of coax. This design use the Seas Excel Coax in a 5 liter (0.17 cu ft) sealed box so it should be possible to make a box that fits your size. A benefit of the coax is that it doesn't care if you mount it vertically or horisontally so you can use it on the side for center and vertical for L&R.

I have no idea if the x-over have BSC or not. Maybe someone here have some tips for us?

Regards

[ThomasW]

The tweeter sound a bit harsh, and little or no bass. The main problem is power handling. Even with active crossover to sub at 150Hz they reach X-max quickly. They work well in very small rooms, but in my livingroom (17 x 17 ft) the sound is to lean.

This is really a computer monitor speaker.

When there's a lack of output in the midbass, the tweeter will sound hot.

People need to understand providing sufficient SPL in a room requires speakers large enough to move a reasonable amount of air. Tiny speakers simply can't do this. In addition speakers work best when there's room for the cone to 'breath'. This is why good loudspeakers are typically deeper than they are wide.

Trying to cram a full range loudspeaker into the depth of a stud bay is an exercise in utter futility.....

This is the a reasonable way to get good sound when one can't place boxes on the floor....

https://www.htguide.com/forum/showthread.php?t=32111

[impulse]

Ok, that thred was educational for me. I looks like a good "ruls of thumb" is to leave at least 2" - 3" behind the speakers magnet. Depending of the woofer size (or total depth of woofer) this woul give an min. internal box-depth of 4,5" - 5,5" given woofer depth of 3,3" and baffle thickness of 0,75". This gives us a box depth of 6,0" - 7,0".

With an internal depth of 4,5" - 5,5" some care should be taken regarding standing wawes. In this example the problem will occur between 2300Hz (5,5" depth) - 2900Hz (4,5" depth).

You say that speakers work best when there's room for the cone to 'breath'. The question is: what is enough room (detph)? I guess this depends on (at least) two things:
1. Size of woofer (is it a 5" or 10")
2. How low is the woofer playing

or?

[ThomasW]

Primarily it's how low and how loud the driver is playing.

Below is my option based on experience, not something I've done exhaustive research studying....

In an optimal situation I think there should be a distance no less than the diameter of the driver from the magnet to the back wall of the cabinet. And the greater the distance the better...

If one uses something like OC-705/703 or 8lb Rock wool behind the drivers, then they can be closer to the back wall.

For a in-wall shallow depth 'box', limit driver size to ~6.5" diameter. Use multiple drivers rather than larger diameter drivers if more output is needed.

[Smokinghot]

http://www.rjbaudio.com/Audiofiles/FRDtools.html

I can't speak enough about this walkthrough. It's made the favourites list of every computer I have at my disposal.

[icetraxx]

I am trying to find/get ideas for a design that does what ThomasW is talking about in the above post. Create a LCR set that is made up of tweeters and 4-6.5" drivers, woofers. Ex. A 1" tweeter, 2 drivers and 2 woofers per speaker. I'm looking for idea to get started and pointed in the right direction. I appreciate that link above it made for some good reading.

[ThomasW]

Pete Schumacker who hangs out over at PE Tech-Talk designed an complete in-wall surround system system called the Frontal Assault.

I can't find a thread about them so you might contact him for info