on Sale - $55/pr (drivers & XO)

[Herman Trivilino]

My ntn backs

For the port I routed a 1/16 larger than the out side diameter PVC pipe I used and @ 1/2 deep. I then used hot glue to secure the PVC pipe and the drilled a hole from the outside and then used a flush cut router bit to route it out to the inside diameter of the PVC pipe and then used a round over bit for the flare.

I did the same thing, except I used gorilla glue. They came out nice. Here are some pics of today's work.

[Chris Roemer]

Re: on Sale - $55/pr (drivers & XO)

Try this . . . take a large drill bit and put a hold through both sides of the enclosure in one pass, then slide a carriage bolt through the enclosure and tighten it (not too much mind you). If you can find a way to counter sink the bolt and nut end then fill with wood filler and sand/finish flat, my guess is that one one would be able to tell.

Not a bad idea, but why not drill a 5/8" or 3/4" hole (through both sides) and epoxy a hard wood dowel through there. All wood.

Chris

[lostboy77]

Re: on Sale - $55/pr (drivers & XO)

Not a bad idea, but why not drill a 5/8" or 3/4" hole (through both sides) and epoxy a hard wood dowel through there. All wood.

Chris

Sometimes I over think things. Your way (of course) is simpler, cleaner, and easier to cover up. If fact, I believe that this may be a simpler method and easier to implement method than installing and securing a internal block brace.

[Chris Roemer]

Re: My ntn backs

I did the same thing, except I used gorilla glue. They came out nice. Here are some pics of today's work.

Nice port installation, but (I wouldn't worry about this, it's just info for your future projects) I like to have a vent NOT centered on the box height. It's usually better to stagger distances in speaker design work, especially trying to avoid "harmonic" dimensions, like 1/2, 1/4, etc.

That's one reason why tweeters are often horizontally offset off the center of a baffle, to give unequal distances from the tweeter to the adjacent baffle edges (where diffraction occurs). For vents, I like to have them 1/3 up (or down) from one end, or 2/5ths or 3/5ths, or 2/7ths, etc. (I think you get the idea). Most people will even stagger the positioning of internal braces, just to avoid reinforcing any certain resonance frequency.

Chris

[Herman Trivilino]

Re: My ntn backs

I like to have a vent NOT centered on the box height.

I just checked, and you're right, it is centered! That's really the only place I can put it if I want it in the back. If you look at the third photo (in Post #346) you can see that if I lowered it to spec it would be too close to the xover board. I was debating putting it in the bottom, but it's too late now.

[ericJ]

Re: My ntn backs

I did the same thing, except I used gorilla glue. They came out nice. Here are some pics of today's work.

It's looking nice, sir. On my PVC port, I just used (gasp!) Titebond II. I used a step down method with two hole saw sizes to make a recess on the inside of the rear panel. Scuffed up the PVC really good, smeared a lot of TitebondII around it, and inside the recess, inserted port in recess, clamped and let sit for a day. I tested this on scrap MDF with a small scrap of PVC to determine how well it would hold. I'm satisfied with the adhesion. If it falls out, I'll repent and eat my words, haha. I forgot to pick up the 5 min epoxy while I was at the store so I just went with what I had.

[fastbike1]

Re: My ntn backs

For your next build, the crossover could be mounted on the bottom, or on the back behind the drivers or on the back lower. The terminals could easily be mounted higher. Lots of options where to mount things. Bottom line is that the port location is a compromise that didn't need to be made. The crossover looks like it could have moved to the back without too much trouble.

I just checked, and you're right, it is centered! That's really the only place I can put it if I want it in the back. If you look at the third photo (in Post #346) you can see that if I lowered it to spec it would be too close to the xover board. I was debating putting it in the bottom, but it's too late now.

[cwad8505]

Re: on Sale - $55/pr (drivers & XO)

Well ... finally got around to ordering the change of/additional components for the NTN build today. All I know for now is the bottom will be removable, XO mounted to that piece. Also, bought my paint at PPG today...don't want to spoil the surprise, but the color is eye-catching to say the least!!:eek: . Hope to get the boxes done this weekend and to the body shop toward the beginning of next week (buddy is going to paint these with automotive finish). These "should" be darn near a mirror finish with the process he describes. I'll def post pix of the finished product and details if anyone wants them. I'm not yet sure if I will build stands or not, I will most likely put these on the dresser in the bedroom and move the ONS to the computer area (sorry Paul...moved, not forgotten!!~..lol). Wish me luck! Chris

[cwad8505]

Re: on Sale - $55/pr (drivers & XO)

BTW... Have there been any NTN photos posted yet that weren't in a "tower" format?? I don't believe I've seen any (not that the towers designs aren't awesome..cuz they iz...).. Thanks, Chris

[Chris Roemer]

Re: on Sale - $55/pr (drivers & XO)

BTW... Have there been any NTN photos posted yet that weren't in a "tower" format?? I don't believe I've seen any (not that the towers designs aren't awesome..cuz they iz...).. Thanks, Chris

They'd work pretty dang well in some of PE's 0.5 cf curved cabinets. ;-)

[GregKramer]

Re: on Sale - $55/pr (drivers & XO)

I just finished a pair of the towers for my brother. 6" x 9.25" x 40" with a 5/8" roundover.
About .74 cubic ft. I have a small compartment in the bottom filled with deconstructed granite to lower the center of gravity. I was rushed on this project and just rolled on the paint with a 4" foam roller. It actually turned out well. 4 coats of primer and 3 paint.
They sound very nice. Thanks for the design.
BTW my Khanspires are behind it.
Greg

[cwad8505]

Re: on Sale - $55/pr (drivers & XO)

They'd work pretty dang well in some of PE's 0.5 cf curved cabinets. ;-)

Wouldn't that just take all of the fun (misery) out of it??!! lol.. I have a plan.. and I believe it will be the most "visually" loud set built yet..
Chris..btw.. on the NTN, didn't u mention to start the top driver's center 4" down from the top (then continue with original spacing)? Also, with regards to the port, where the does the length actually start... from inside the baffle..or from the front of the baffle.. in other words, if I wanted to do a pvc port 7" long, flushed with the back, should it be 7 or 7 3/4? I know the port issue has been covered over and over, but this part still confuses me (doesn't take much!) Thanks.. the other Chris

[ericJ]

Re: on Sale - $55/pr (drivers & XO)

Mr. FedEX left me a gift today for my build. A 2x8 sheet of maple veneer from formwood. NLB. Standard grain, nothing too cool. Closeout price of $15 and some cents. $34 shipped.

Plans are to veneer top, bottom and sides. Flat black baffle and rear. I have maple cabinets and some stain to match, so these will be in that realm.

The other Chris..that finish sounds hot. You doing that funky color change paint that was on all the cars a few years ago?!

[cwad8505]

Re: on Sale - $55/pr (drivers & XO)

The other Chris..that finish sounds hot. You doing that funky color change paint that was on all the cars a few years ago?!

I think they call that Harlequinn?.. actually looked that over at PPG today..not what I went with. Doing my drawings tonight and now realize why everyone's doing the NTN as a tower..wasn't until I put it to paper that I realized how tall it already is.. think I'm gonna stick with 28" tall and build an optional base depending on where they sit... Def post pix of that veneer job when you get done! Chris

[Herman Trivilino]

Re: My ntn backs

The crossover looks like it could have moved to the back without too much trouble.

I want the crossover to be visible through the window on the front of the cabinet. These will be in a classroom/lab and I want the students to be able to see the circuit elements. It's a nifty application of the use of resistors, capacitors, and inductors.