Heavily modyfied Overnight Sensation for surround and Atmos use

[roadrune]

I can not find much info on DIY Atmos speakers, so here is my take:

Sorry US guys, all measurements are in metric.

As i got a new amp with support for Atmos and DTS:X (Denon AVR-X6200W) i wanted Atmos speakers to upgrade from 7.1.

Being pretty low on cash after bying the amp i decided to use what i already had:

My "old" surrounds is 4x Overnight Sensation bipoles, therefore i already have 8 woofers (HiVi B4N) and 8 tweeters (HiVi T-20).
I wanted a lower profile than the original OS speakers and the bipoles, also i wanted all speakers to be wall and ceiling mounted, which ment the port had to be moved.

After some thinking and messing around with the calculator i ended up with a design which gave a total depth of 115mm and with a slot port opening at the baffle.
I have kept the original internal volume of just under 4,5l and added just a little bit to compensate for the port. The baffle size is almost the same, just 1,6mm lower and 12mm wider.

So i made a but-ugly prototype of my design, and also a original OS (only with slotted port) to compare the sound as i had no idea if this was going to work.
Crossover is the original Paul Carmody design for the HiVi tweeter (only difference from Dayton tweeter is a 15ohm resistance instead of the 10ohm in the L-pad)
I also used 1" polyfill covering the entire back except for the port opening.

This actually sounded a lot better then i would have expected, and i could not tell any difference in the sound from the two.

So i am going to build this, so here is my cut-list which should be enough to build them from aswell if anyone would be interested. This list is for 12mm stock (1/2") (i will use MDF but i suppose plywood will be better) The list is for 8 speakers and using a standard full panel 1220x2440mm or 8`x4`in the US.
I am not shure if a brace on the back panel would be needed, but i think i will ad one just in case.

Only info i can think of is missing from this drawing is the port lenght which shall be 152,4mm and a cutlist for the port pieces which will depend on what stock you are using. The ports sectional area and lenght is the same as the original.
The low profile of the speaker will require a bend in the port to get the correct lenght.
I will also use a roundover bit on all port parts that can interfere with the airflow.

I think thats it, give me a shout if somethings missing.

Hopefully i will start chopping wood this weekend.

 

[roadrune]

Got to cut all the parts today, 48 pieces plus 48 for the ports.

I just cannot tell you how happy i am with my tracksaw for this kind of job, all parts are within 1/10mm tolerance and all cut by hand in less then two hours.

 

[roadrune]

I decided it was just to fiddly with all the small parts for the ports, so i made new ones from a piece of 3/4 mdf i had.

Much easier with just two pieces per port instead of 6.

 

[roadrune]

A small tip:

This drillbit is by far the best i have found for holes in MDF which dont have to be super-accurate.

Its fast and easy.
And its really cheap.

Standard holesaws are no good on mdf since it will easily clog and burn, and the special holesaws for mdf i stupidly expencive here in Norway. 50-60$ each plus the holder. That means more then 200$ just for this project.

 

[roadrune]

Partly assembled box showing the port layout:

And all 8 assembled.

 

[panteragstk]

Very nice indeed. I've been thinking of an on ceiling speaker for my Atmos install, but haven't really stumbled across anything good. I like your approach.

So, if I'm reading this correctly you are going to have matching speakers for surround back, side, and ceiling mounted atmos speakers? Should sound awesome.

 

[roadrune]

Thank you.

Yes, i will have 8 of theese. 4 for side/backspeakers and 4 in the ceiling for full Atmos (7.1.4)

 

[roadrune]

All finished

I forgot to paint the porthole black, so that need to happen, but other then that they are all placed, connected and calibrated with Audyssey.

Just finished them up late last night, so i only played a couple of tracks from Roger Waters The Wall in Atmos, and they sound great.
Actually for its pricerange they sound absolutely awesome!

I can recommend this to everyone wanting a good sounding atmos/surround speaker on a budget.

 

[TheWarrior]

Excellent tip on the mdf cutter for a drill press... me thinks I need to get my Dads old drill a new motor!

Quick questions, love the assembly line production you've done, but what about the crossovers?

 

[rojo]

Nice work! I think the title of your thread is throwing people off. Since this thread started, I've seen "Heavily modified OS" and just thought, "Why would an operating system need to be heavily modified to produce surround sound? Meh, pass." Saw your shameless self-promotion in the New design by Murphy / Kittinger thread, so I figured I better give this thread a look. Glad I did now.

 

[roadrune]

Excellent tip on the mdf cutter for a drill press... me thinks I need to get my Dads old drill a new motor!

Quick questions, love the assembly line production you've done, but what about the crossovers?

The crossovers are standard OS so i didnt bother mensioning them except in the OP.

 

[roadrune]

Nice work! I think the title of your thread is throwing people off. Since this thread started, I've seen "Heavily modified OS" and just thought, "Why would an operating system need to be heavily modified to produce surround sound? Meh, pass." Saw your shameless self-promotion in the New design by Murphy / Kittinger thread, so I figured I better give this thread a look. Glad I did now.

Good point, maybe a mod can change the title to Overnight sensation instead of just OS?

 

[slipperybidness]

All finished

View attachment 19832 View attachment 19833

I forgot to paint the porthole black, so that need to happen, but other then that they are all placed, connected and calibrated with Audyssey.

Just finished them up late last night, so i only played a couple of tracks from Roger Waters The Wall in Atmos, and they sound great.
Actually for its pricerange they sound absolutely awesome!

I can recommend this to everyone wanting a good sounding atmos/surround speaker on a budget.

That is some nice looking work!

How did you finish the cabs? Is that a vinyl wrap?

 

[roadrune]

Yes, its a cheap self sticking vinyl thing from China. Bought it on ebay, really nice to apply, and with a decent finish.

 

[slipperybidness]

Yes, its a cheap self sticking vinyl thing from China. Bought it on ebay, really nice to apply, and with a decent finish.

Looks good in the pics. The only vinyl wraps that I have done, I always used the high quality 3M stuff. It went on very easily and worked out well.

 

[roadrune]

This is quite different from the 3M stuff in both quality and use. This is more like a sticker that cannot be moved around.

I would provide a link, but i cant find my ebay history from my mobile. Will fix it from a computer next time im in front of one.

 

[roadrune]

Looks good in the pics. The only vinyl wraps that I have done, I always used the high quality 3M stuff. It went on very easily and worked out well.

Here's the stuff: http://www.ebay.com/itm/Self-Adhesive-Wood-Grain-Peel-Stick-Wallpaper-Vinyl-Sticker-Film-Sticky-Back-/262304846509?var=&hash=item3d129652ad

 

[yonyz]

Is the purpose of the odd shape of these speakers to increase volume while keeping the speakers relatively shallow? Or is there an acoustic benefit to this shape?

 

[roadrune]

The purpose is to get a shallow profile while maintaining internal volume AND the bafflesize.

Making the baffle wider would have changed the bassresponse.

 

[andy.close]

@roadrune, are you using you OS Atmos speakers with your ER18's as the mains? did you ever get the midrange issues worked out on your ER18's?