fEarful 12/6 kit : a total noob build diary

[ScotJam Bassie]

Thanks for sharing this, I am seriously considering building one of these or the 15/6/1.

Q. Is the acoustic foam you are using ok/normal for this build? I am guessing it is lighter than acoustic fibre based insulation, but was wondering if type of inside dampening affects sound in a big way, especially in the 6" box?

 

[mambo4]

I'm no expert, but the 2" egg carton foam I used came direct from Speaker Harware. It's evident from others pics that there are a variety of choices for the interior damping material. I'm curious about the physics involved too, but I'm just following the instructions.

For the midrange, Speaker Hardware does specify a different damping material for the more expensive speaker choice. May have more to do with speaker size and the room needed than the acoustics, IDK.

 

[mambo4]

wondering if little dabs of PL are good enough to fill the screw holes? Or is it wiser to get some elmers + sawdust?

 

[wcriley]

A lot of people, including greenboy's authorized builders, use autobody filler.
I used drywall mud because it's what I had on hand.

 

[Roxbororob]

I have used the PL. You need to force it in deep with a putty knife or cardstock. It will expand and protude while curing. Once cured, slice off the protrusion with a sharp chisel, box cutter or other.

 

[Redbrangus]

The DuraTex manufacturer recommends drywall/spackling compound for adhesion reasons, which I guess is OK enough for small nail holes and the like. I used to use auto body filler, but for the past 20 or more years I've used a product called Durham's Rock-Hard Wood Filler. It's a lot cheaper than Bondo, but probably just as durable in cabinet work. It's a dry powder that mixes up with water, so there's nothing that will go bad in the can. The PL would certainly work if you have some and you can get it worked into the hole. It would just be a little harder to shape or sand.

 

[Blues Bass 2]

I've used drywall mud too , thats what the Duratex people say to use , and it's worked real well . By the time it drys and you put the duratex on it's pretty strong . Sounds like Redbrangus has a good idea I might use someday .

 

[ddezz]

Following a recommendation from this thread, I started with the mid range box first. I chance to try out my first counter sink drilling.
View attachment 3843460

First crew split a bit of the wood. I was too timid with the countersink.
View attachment 3843467
Second one I gave a deeper bevel with lots of clearance.

View attachment 3843468

Eminence came out with a new version of the 6 A speaker which has a solid metal basket which could eliminate the wood box.

 

[Balog]

Eminence came out with a new version of the 6 A speaker which has a solid metal basket which could eliminate the wood box.

Interesting. So is it like it's own built in enclosure?

 

[Passinwind]

Interesting. So is it like it's own built in enclosure?

Yep. Unless it's something new the sealed back Alpha mid drivers have been around for quite a few years and Dave Green always recommended against using them in fEARful builds quite vehemently.

 

[Balog]

Yep. Unless it's something new the sealed back Alpha mid drivers have been around for quite a few years and Dave Green always recommended against using them in fEARful builds quite vehemently.

Why is that?

 

[Passinwind]

Why is that?

Too much undamped back reflection.

 

[Doufuss]

I have both. The Alpha 6a is very smooth all the way through its frequency range.

The CBMRA? Not so much. Although it is much more sensitive.

 

[mambo4]

Just little work filling and sanding , in preparation for the duratex.

 

[mambo4]

I started looking at the speaker parts and stumbled across a puzzle. The mid range and bass speakers will screw in to the baffle. But how is the tweeter meant to attach? I had assumed the horn would somehow hold it in place, but there is no way those two ends are meant to match up. The threaded tweeter is almost 2x the size of the socket on the horn.

Did I just receive incorrect parts? Is something missing?

 

[Redbrangus]

Although I really can't speak authoritatively, it appears you've either got the wrong driver altogether, or you're missing the adaptor plate that bolts to the face of the driver and provides the threaded portion to mate with the horn. Without knowing one other thing about it, I'd bet on the second one -- you're missing an adaptor plate.

Edit: Did you purchase the horn and driver as individual parts, or as part of a kit? Using an adaptor plate is not at all uncommon with screw-on horns, but the supplier may not have made that clear in their information. It happens.

 

[singlemalt]

Can you unthread the brass from the horn lens?

It’s been a while, but I seem to remember the driver had a threaded section that screwed into the plastic horn lens. If these parts had already been screwed together, and dropped, you could be looking at a broken driver.

I remember mounting the horn lens and then screwing the driver on to, or in to, the lens.

I’d go look at the Parts Express site and see if there are good pictures of the two parts.

"Eminence ASD1001 1" HF Titanium Horn Driver 1-3/8"-18 TPI" from www.parts-express.com!

"Dayton Audio H07E 6" x 6" Elliptical Waveguide 1-3/8"- 18 TPI" from www.parts-express.com!

What I’m seeing, the brass threads are supposed to be in the wave guide, (I’ve been calling it a “lens” for some reason) and there should be a threaded section on your driver. Looks like the driver is broke. Any extra bits in the bottom of your shipping box?

 

[Foz]

ya - looks like your horn driver is missing some bits - contact seller for replacement

https://www.parts-express.com/pedocs/specs/290-525--eminence-asd-1001-spec-sheet.pdf

 

[Blues Bass 2]

They gave you a bolt on driver instead of the screw on one that will screw into your horn . Foz is right , get hold of the seller to get the right one .

 

[mambo4]

been a while since I updated.

I contacted Leland at Speaker Hardware, and as always he was accommodating. He sent me an attachment flange piece which bolts on to the tweeter, and threads into the horn.

I also finished soldering the crossovers and hot gluing/screwing them onto a piece of scrap wood:

I had to adapt the circuit boards I ended up with , but I carefully checked and double checked what I was doing against the diagrams, so I am pretty sure I got it right.

I started gathering the speakers and stuff together and consider how to wire it up and assemble, and I decided I should solve all the connecting first before attaching anything to the speaker cabinet. So, it's off to the hardware store to gather some small bolts and nuts for the flange, some spade crimping connectors, and some extra 18 gauge wire, just in case.