NE225W+PM180+ViaWave Design & Build Thread

[jml]

Greetings!

I thought that it would be good etiquette to start a single thread for all questions and progress updates on this (yet to be named) project. Hopefully this makes it easy to follow from beginning to end, and keeps my obtuse line of questions contained to a single thread HAHA!

The next order of business is finalizing box volume(s), so that I can get the dimensions finalized before making some sawdust.

Below is my first draft using UniBox to model the NE225Ws. The one issue that I seem to keep running into, whether I model it with 1 or 2 ports is Port Air Speed. Either way, increasing the port ID enough to reduce the air speed results in impractically long port lengths. How much of a concern is the air speed with a rear-facing port with a 1.5" round-over?

As always, thanks to everyone for your knowledge. I look forward to learning a great deal throughout this build, and hopefully giving back to the forum throughout the process.

Cheers!

Joe

[johnnyrichards]

Re: NE225W+PM180+ViaWave Design & Build Thread

Greetings!

I thought that it would be good etiquette to start a single thread for all questions and progress updates on this (yet to be named) project. Hopefully this makes it easy to follow from beginning to end, and keeps my obtuse line of questions contained to a single thread HAHA!

The next order of business is finalizing box volume(s), so that I can get the dimensions finalized before making some sawdust.

Below is my first draft using UniBox to model the NE225Ws. The one issue that I seem to keep running into, whether I model it with 1 or 2 ports is Port Air Speed. Either way, increasing the port ID enough to reduce the air speed results in impractically long port lengths. How much of a concern is the air speed with a rear-facing port with a 1.5" round-over?

As always, thanks to everyone for your knowledge. I look forward to learning a great deal throughout this build, and hopefully giving back to the forum throughout the process.

Cheers!

Joe

[ATTACH=CONFIG]64043[/ATTACH]

[ATTACH=CONFIG]64044[/ATTACH]

Try modeling it at listening levels that do not result in permanent hearing loss, like, say 90-95db.

[PWR RYD]

Re: NE225W+PM180+ViaWave Design & Build Thread

+1

That's an unrealistic input power and SPL.

[jml]

Re: NE225W+PM180+ViaWave Design & Build Thread

Thanks guys! I did mention that there would be obtuse questions in my original post - glad we got that out of the way.

I've lowered the input power, and it models well without any port noise issues.

[PWR RYD]

Re: NE225W+PM180+ViaWave Design & Build Thread

That's much better.

[johnnyrichards]

Re: NE225W+PM180+ViaWave Design & Build Thread

Nothing drives home how much we listen to two or three watts almost exclusively than an SPL output chart. Once I decided to stop modeling for bleeding ears, I found it is okie-dokie to use smaller-than-ideal ports. I never even top 95db when drunk and listening to 80's hair bands these days, much less when listening for relaxation and emotion.

[jml]

Good Afternoon!

I finally have another update on this project. I got all of the panels for the "inner cabinet" of the design cut today. The cabinet panels interlock via a channel cut into the inner surface of the front and back baffle. There is 1/4" of overhang intentionally, as the "outer cabinet" panels will have a channel cut into them that interlocks over the overhang. The inner cabinet is MDF, and the outer cabinet will be real wood "cladding" varying in thickness from 1-2" for a total cabinet thickness of between 1-3/4" and 2-3/4" - with the exception of the front/rear baffles, which will be 2 layers of 3/4" MDF.

The "double-interlocking" design should be extremely rigid when glued up. The one thing that I would do differently next time would be only going 1/8" deep with the channel. As the channel is 1/4" inch from the edge of the board, the "lip" at the edge of the board is relatively fragile, and it broke off while routing on one of the board. Only going 1/8" deep would have made the lip stronger, created less dust, and probably gotten 90% of the benefit of this construction.

I would honestly consider using this construction again simply to make the glue up that much easier - you could glue it up, and then route the edge off with a flush-trim bit.

Cheers!

Joe

[jml]

Good Evening!

Just a quick update on this project. The inner cabinets are all glued up, and now it's on to the exterior and finish work.

Cheers!

Joe

[jml]

Good Evening!

i've started working on the exterior cabinet for this build. The sides will be a "faux translam" construction, which has been very labor intestine - 80 pieces per speaker.

Attached is the sequence of operations to get the concave curve into each of the pieces. I haven't yet rounded over the corners, but I will be putting a 1.5" round over on all 4 corners. I'll also be putting a very small 45 degree bevel between all of the pieces in order to create a "v" between each 1" this piece.

I haven't quite figured out if I want to pull out the boards with knots or leave them in. I'm also debating on staining them dark (like dark walnut or similar) or leaving them natural. What do you guys think?

Cheers!

Joe

[bill poster]

Wow impressive work. Interesting choice of drivers too.

[6thplanet]

Cool, that should have a pretty unique look! I'm diggin it.

[jml]

Thanks for the comments. The way that the curve exposes the wood grain on some pieces is pretty cool looking. I went through the stacks for all 4 sides today and pulled out some of the pieces that had large knots in them - the diversity in the grain between boards is all part of the look, but I decided that I didn't want them to look "rustic". At this point i'm thinking of leaving them natural in color and just rubbing on a clear wax finish.

Hopefully I'll have updated pictures of the cabinets assembled within the next couple weeks.

Best regards,

Joe

[r-carpenter]

Ambitious project! Looking forward to the progress.
One comment on wax. Wax, by itself offers very little protection and tends to attract dust and dirt. If you would like to keep the color of the woof as unchanged as possible, waterborne coat of clear finish would do the trick. And top with a thin coat of wax.

[jml]

Roman:

Thanks for the input on the wax. I hadn't thought about that aspect of it previously. I've finished projects of oak and ash previously with just stain and clear wax, but they haven't been around long enough to see what happens to the color over time. i'll definitely do some testing with spraying on a light coat of water-based finish and then rubbing on a thin coat of clear wax.

Cheers!

Joe

[jml]

Happy Memorial Day All!

Attached are some updated build pictures. All of the "staves" for the sides are complete and glued in place. Between the two speakers there are 156 staves. Over the course of all the operations to make each one, I probably lost about 15% to scrap due to tear-out, warped boards, excessive knots etc... The boards started out slightly over 1" thick, and in order to get them to stack up to exactly 39" I had to plane them down to .998" each. This process highlighted the issue of "stacked-tolerances", as I originally planed them down to exactly 1.000", but when stacked they required excessive clamping pressure to get them down to exactly 39".

Now that this part of the project is done, I expect progress on the tops, bottoms, and baffles will come quickly.

Cheers!

Joe