My first 3-way build thread. Working name: Ava

[duanebro]

I have started several threads about different drivers I have. I think that I should make a thread to track the design, and build, of this speaker. So here it is:

Before I get to the drivers I would like to note that this all started at InDIYana when I won, as a door prize, a set of Airborne 4101 "ribbon" tweeters. I have always wanted a set of speakers with ribbon tweeters, but they were always to much money. So I was determined to use these. Everything else is just trying to make these work.

The Drivers:
Tweeter: Airborne 4101 $30 each. http://www.solen.ca/pdf/airborne/rt4101.pdf
While billed as usable to 4K, I have found, and Wolf did before me, that they drop off at 8k. The back is open and attenuated ~10db. The interesting thing is the back wave is fairly flat down to 5K.

Mid: Vifa TC9 $12 each.
http://www.parts-express.com/pe/show...umber=264-1062
The 8 khz xo point for the tweeter led me to look for a mid that could go that high. With the help of the guys at PETT I found the Vifa TC9. (Thanks, Don, Sidi, and RPB) This looks like a very nice driver. It will be rear mounted just below the 4101.

Bringing up the bottom end will be a Aura Sound NS6 8ohm version. This is because I have them. If I had a larger woofer I would use it. The high sensitivity of these should make up for baffle step loss.

The Crossover:
I won't do much here until the enclosure is built. But at the high end the xo point will have to be about 8Khz. And the lower xo point could be as high as 1500hz.

The enclosure:
Modeled but not yet built. A large TL for the NS6. Hornresp shows a f3 of ~37hz. Yes, power handling is a weakness of this design. I am going to be building a test enclosure asap to try to decide if the NS6 will be enough. The design is a 9" wide baffle about 13" deep. This depth includes a 30-30-30 triangle on the back. If I like it then I plan on bending 1/4" ply around the sides. The gaps will then be filled with something very dense. Concrete most likely. I would think that this would result in a very dead box. And heavy of course.

[duanebro]

I don't think any one has used the Airborne 4101 before. With the back wave attenuated ~10db would using it OB be of any use?

With the tweeter having a very controlled vertical pattern would trying the mid in a elliptical wave guide help to match the tweeters dispersion? If this would work - does any one know where to start? Is there a program to model it?

BSC - with a 9" baffle the baffle step loss starts at 1500hz. To use the woofer to make up for this I think I need to be considering a xo point at that frequency. So my driver spacing should be kept at or below one wave length, or 9" Before this I have just put the drivers as close as I could and not worry about it. Because of the TL design this could be an issue. I hope that someone with more experience could help me out on this.

Thank you,
Duane

[johnnyrichards]

I think this will be a lovely budget 3-way. What are your eventual plans for them?

[duanebro]

I think this will be a lovely budget 3-way. What are your eventual plans for them?

I would like to show them at MWAF this year. But I very much doubt that I will be able to have them ready. Other than that, I don't know.

[donradick]

Nice plan!
But -
I don't think you should try for 37 Hz on the NS6 - maybe a largish bookshelf to about 50 Hz or so. Other than that, the combination sounds very groovy.

[duanebro]

Nice plan!
But -
I don't think you should try for 37 Hz on the NS6 - maybe a largish bookshelf to about 50 Hz or so. Other than that, the combination sounds very groovy.

My second choice is sealed. Then add a sub.
I avoided ported because my last two builds were ported with output to about 50 Hz. My goal with the design was close to 40 Hz. The model got tuned a bit lower when I drew up the box. (I changed the length a bit.) I will try to get a prototype box done this week and get some measurements, normal plus ground plane and distortion.

[rpb]

I don't think any one has used the Airborne 4101 before. With the back wave attenuated ~10db would using it OB be of any use?

With the tweeter having a very controlled vertical pattern would trying the mid in a elliptical wave guide help to match the tweeters dispersion? If this would work - does any one know where to start? Is there a program to model it?

BSC - with a 9" baffle the baffle step loss starts at 1500hz. To use the woofer to make up for this I think I need to be considering a xo point at that frequency. So my driver spacing should be kept at or below one wave length, or 9" Before this I have just put the drivers as close as I could and not worry about it. Because of the TL design this could be an issue. I hope that someone with more experience could help me out on this.

Thank you,
Duane

I would use the mid flush mounted, and keep things simple. I don't feel that directivity is much of an issue crossed that high. The Vifa mid should be pretty easy to filter for a 400 to 600 hz highpass x-over, since a 9" baffle usually makes a bit of a bump at 800 hz. Your highpass filter on the mid can be used to smooth that bump, and the resulting -6 dB point will probably fall around 500 hz or so with little effort required.

[WernerM]

Duane,
Don did a very good right up using the NS6 in his MAURBACS build, maybe some useful info for you there...

[marscoast]

I'll be interested to see how you make out with that TC9 as a mid. I picked up a pair about 6 mo ago - still waiting patiently on the shelf for me to catch up.

[duanebro]

I have not had time to do any cutting yet. But I did get some practice in with autocad: The top view on the left pic shows my idea for making curved sides.



And I have seen Don's designs with the NS6. I like how simple his xo is. I have some rs-150s drivers also. If I step back from this TL to a sealed design I may see if I can use those. For now I will play this idea out. Things I didn't draw are enclosures for the mid and tweeter and removable baffle. I will just use the NS6 at first. Then decide how I want to proceed.

[WernerM]

I like it!! I will definately keep an eye on this one

[duanebro]

So I started cutting today.


I did run into one issue. The angled pieces at the bottom and top of the box I put in to keep the line at about the correct sq. area require a compound cut. How important is it to put these in? Is there an easy way to cut them? I have a miter fence for my table saw that is very loose in its guide. so I never use it. I also have 10" miter saw that can cut about 6". So I would need to turn the piece around to finish the cut. What would you do?

Thank you,
Duane.

[WernerM]

I like the way you are using the clamps and a level to create a fence for your skillsaw. I was thinking I would have to use a 2x4 screwed o the MDF, but i didn't want to because of obvious screw holes. Looks like I'll be picking up some clamps...

[duanebro]

You need clamps.... Once you have a few you will want more. I have 5 and am always short a few! Lol. I recommend the ones in the pic. You can find them at your local discount tool shop. Just avoid the cheap plastic ones. I use that setup you see because I can't use the table saw on big pieces. It seems backwards but table saws are for little pieces. There is a better saw fence you can/should make with just a little wood. I am on my phone right now but an internet search should find it.

[takitaj]

If you have a Lowes nearby this is invaluable and well worth the money if you don't have a table saw, or just would rather use the hand saw.

[duanebro]

I did some more work tonight. I should never make angled boxes again. They are way harder than rectangles. Here are a few pics:




This last picture shows my way to clamp the angled piece.

[donradick]

Ambitious angled design, particularly with your tool set. I have enough trouble with rectangular boxes, myself. Maybe one day...

[duanebro]

Ambitious angled design, particularly with your tool set. I have enough trouble with rectangular boxes, myself. Maybe one day...

I am only building one. If I like it I have to build another.

[duanebro]

I got it glued up and played some music through it. It works, I will have to get the omnimic out when i get a chance... But that might not be until later in the week.

I have a trig test tomorrow I've got to get some sleep.

[duanebro]

Ok, so I took 10 days off. Well maybe not. I have been trying to work on this when I can. Here is what I am listening to so far:

The sims don't match up with the omnimic. I need to get the fr graphs off the laptop, but they are quite bright. I need to get outside and get some good measurements, I just need more hours in a day. LOL
The xo:
woofer: 3mh and 40 uF
Mid: 18uf (High pass), .4mh and 2.2 uf (lowpass)
Tweeter 1.55uF and .1 mH
I have thought of just using a 1uF cap on the tweeter:


Seems like it might work.

If anyone can help with the TL (stuffing mostly) Plese let me know.