Foam Core Board Speaker Enclosures?

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Decware DNA horn in FC?

I just ran across this speaker which claims to be the most compact BLH. It supposedly reaches into the 20 Hz region with a TB W5-1880. Being only 28 in tall and 12.5 in deep x 8 in wide, it lends itself perfectly for fitting into a sheet of 30 in x 20 in FC stock. This is a rear-facing mouth horn design, which I have to say, I really like based on my listening experience with the FC FH3-inspired speaker that I built. This may be a fun and interesting build as there isn't anything complicated about the passages. It has a massive driver chamber and tiny aperture leading to the horn - this is probably how the upper frequency fh is controlled so that only bass output comes out of the horn. It would be interesting to simulate it on AkAbak or MJK first. Anyone interested in this build in FC or otherwise? I will have to estimate dimensions from the images available...

The DECWARE DNA Horn

decwarehorn550.jpg


In case you are wondering what is in the black compartment at the bottom, that is the optional 6 watt SET amp - built in tube amp.


edhorn0.jpg


edhorn17.jpg


dnaresponse.jpg
 
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I'm going to do a perspective correction on the main drawing above to make it planar. Then use dial calipers to pull off the dims. That's a reasonable price for plans but I am happy with my pulling rough dimensions. I have a budget driver in mind too, the 5 in aluminum cone full range driver from MCM for $13. It has specs almost matching the W5-1880 (which is discontinued). The MCM 55-1870. MCM Audio Select 5'' Aluminum Cone Woofer | 55-1870 (551870) | MCM Audio Select. There is no harm done if it doesn't work out. However, I have a suspicion that it will sound quite nice for a $17 speaker.
I need to buy some hot melt. All out :(

Might be a good opportunity to try thicker foam board? Don't know yet.
 
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Founder of XSA-Labs
Joined 2012
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Founder of XSA-Labs
Joined 2012
Paid Member
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Founder of XSA-Labs
Joined 2012
Paid Member
Decware DNA-inspired speaker dimensions

Here is what I managed to get for dimensions of the DNA BLH. Following the procedure we used to layout the Cornu, it would be much easier to make a scale drawing from the pdf file (in full size) and then transfer to the foam core or plywood board. I have some dimensions measured more for purposes of modeling the horn in AkAbak. It is 27 in tall x 7 wide x 12 in deep (internal). The baffle cutout is 4.80 in dia located such that top edge of cutout is 4 in from top of cabinet. The diameter of the internal throat hole is still TBD and I think will best be left for tuning based on calcs dependent on driver. I am guessing it is around 2 to 2.5 in dia.

Good luck on this build! :)
 

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I thought the goal was extension not SPL. I've told the story before, but a Detroit audio store in the 60s had a 3 or 4 watt, as I remember Bozac, demo that could drive you out of the room. Their pitch was the purity of the signal coming from the amp.

Here is a similar report.

Bozak Concert Grand.

I'm just wondering if foam core can handle anything as powerful as those big Pyle amps.
 

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I have no experience with the MCM driver but it seems to have about the right Qts, Sd, Bl, but the Vas is off. The price is right. If you have another 5 in driver you want to try let me know. Once I get this in a AkAbak model, we can play with the throat dia or chamber volume to tune it. The W5-1611saf may be closer to what it was designed for but those are pricey. The Fostex FF125wk can probably work too. When I look at this BLH design it strikes me as having the biggest driver chamber ever. I am thinking it is more along the line of a bass reflex with a horn expansion vent - a very big horn BVR. The dtiver chamber vol probably has to be tuned to the driver Vas and Qts in a BR program to determine the throat dia which is essentially the BR vent. Someone with more knowledge in this may want to jump in and help out. This is my thinking though. The MCM driver has about half the Vas of the TB 1880, so the chamber vo.ume will probably drastically get cut?