Project L.O.K.I. Build thread.

[Dabspok]

Did I mention, those are going to be some sekci speakers?

[Pete Schumacher ®]

OK, some preliminary sims using the measured data I got from the RS28A on the sample baffle Ed sent me, and some traced and modified (Response Modeler) RS225 files. This is aiming for a baseline 89dB, or about 3dB overall BSC. XO is right at 875Hz, LR4, with 4 components on the tweeter, and 6 on the woofer. The breakup hash of the RS225 is over 45dB down. The bass alignment is probably not what I'll finally use, but it's close enough to get a potential crossover going. I'll likely tune the enclosure in the low 30s and not the upper 20s, as shown here.

[BeeTL]

Pete,

You've mentioned on several occasions that Ed could machine a custom baffle using the RS28 waveguide.

Do you think he could do one in a 1 1/2" thick laminated hardwood blank, something like this?

[D, Rose]

The WG needs to be 2" thick. What I normally do is use the W. cut-out for the "donut", epoxying the waste for the extra WG thickness needed. I'm working on a cutter that will make using hardwood possible. As for now the machine I use is just a big pantograph with a router instead of a pencil. It takes literally thousands of cuts to get a WG. I then sand the rough profile smooth. With MDF I can use a little body filler on an errant groove here or there. That isn't possible with a beautiful hardwood blank, so theres some risk involved. Hopefully my new cutter(if its even possible to make!) will make using figured hardwoods possible. I'm in the process of moving, and I had to promise the wife 2 weeks of no speaker involvement. This may kill me after being at AK fest!

[BeeTL]

Cool!

I'm thinking the material I'll end up using will be 1" (actual) thick, so doubling up the woofer cutout could be ideal.

I'm still in "what do I want to do for my first project?" mode...

[saabracer23]

Any progress with this build? Was it pushed to the side?

Dan

[Pete Schumacher ®]

Any progress with this build? Was it pushed to the side?

Dan

On the back burner at the moment. Everything came to a grinding halt when Ed decided to move his family 30 miles to a new home.

Hopefully we'll see a bit of movement after October.

I do have a couple of smaller baffles that will only work with a single RS225. It could be adapted to a PE cabinet and make a TM I suppose.

I might just have Ed send me his idle pair of RS225-4 and do the straight up 2-way.

Thanks for bugging me about this.

[aarond]

On the back burner at the moment. Everything came to a grinding halt when Ed decided to move his family 30 miles to a new home.

It could be adapted to a PE cabinet and make a TM I suppose.

I might just have Ed send me his idle pair of RS225-4 and do the straight up 2-way.

Thanks for bugging me about this.

Pete,

Just so you know there is interest in this... I had intended to build exactly what you propose. I was have been waiting for D Rose to make a pair to fit the PE cabs but it has been several months. Now that there is another member willing to do CNC work I might go that route. I had been in contact w/ Mark K about updating his RS22528a project with the newer PE drivers and this WG.

I have 4 of the original RS225-8's. What I would REALLY like is a design that would allow me to add those to the 2-ways eventually (in seperate boxes). I'll be home from deployment in less than week. I already cut the baffle for the driver and passive radiator for the seperate RS225 while I was on leave. I will probably build my own box for the PE sized baffle shortly after I get back. I need to get the 2-way WG baffle ordered so I have it when I get everything else built. My original plan was to play with this as an active setup until someone comes up with a more permanent crossover design.

[TN Allen]

Pete,

Just so you know there is interest in this... I had intended to build exactly what you propose. I was have been waiting for D Rose to make a pair to fit the PE cabs but it has been several months. Now that there is another member willing to do CNC work I might go that route. I had been in contact w/ Mark K about updating his RS22528a project with the newer PE drivers and this WG.

I have 4 of the original RS225-8's. What I would REALLY like is a design that would allow me to add those to the 2-ways eventually (in seperate boxes). I'll be home from deployment in less than week. I already cut the baffle for the driver and passive radiator for the seperate RS225 while I was on leave. I will probably build my own box for the PE sized baffle shortly after I get back. I need to get the 2-way WG baffle ordered so I have it when I get everything else built. My original plan was to play with this as an active setup until someone comes up with a more permanent crossover design.

If you can use turned waveguides, I would do two for you free to Pete Schumacher's dimensions, which I used to turn a set of guides for Dave Pellegrene. If I remember correctly(I'll need to check), one of his has a 3.950" radius, which is what was discussed on the Forum a few months ago, and the other radius is minus .125", or 3.825" to accommodate the thickness of the plastic he uses. The jig I built produces uniform cross sections, the outside diameter can be whatever you like up to about 14". The cross section is tangent on about an 8.5" diameter depending upon the thickness and throat opening diameter, and the thickness is about 2.25". I usually make the guides deeper so the back can be milled out using a router to a depth that opens the throat to the appropriate diameter and accommodates the tweeter face plate. Depending upon the material you want, I may be able to give you that as well as the work. I offer because I am curious about the response of these guides and it seems you are likely to provide data upon completion of your project. Let me know if you are interested.

[aarond]

I offer because I am curious about the response of these guides and it seems you are likely to provide data upon completion of your project. Let me know if you are interested.

TNA,

I'd definitely take you up on it if I had the measurement capability. I would also like to get this info out to those that can use it. I was going to foot the freight to Mark K so he could measure and design. I wish I could be more help on this. I'm not sure how tight Pete's time is but I guess could order some baffles from the new CNC source and have them sent to Pete so he could get the ball rolling. Another option might be to have you fab the guides and I could do the rest of the work necessary to build the baffle but that would require 3 people to be involved in shipping/fabricating something instead of just two if I were to get them CNC'd.

I'm open to whatever gets the job done. Just tossing out ideas.

[Pete Schumacher ®]

If you want to get the guide CNC machined, here's a drawing that defines it very closely and could easily be turned into a 3D file for the cut. I have the RS28F and RS28A on hand to get plots, and the sim above is using actual measured response. Still, final voicing is a personal preference, so modification of values is to be expected.

[saabracer23]

On the back burner at the moment. Everything came to a grinding halt when Ed decided to move his family 30 miles to a new home.

Hopefully we'll see a bit of movement after October.

I do have a couple of smaller baffles that will only work with a single RS225. It could be adapted to a PE cabinet and make a TM I suppose.

I might just have Ed send me his idle pair of RS225-4 and do the straight up 2-way.

Thanks for bugging me about this.

No problem. Please continue on the idea of a TMM. One of my favorite commercial speakers of all time is the Klipsch RF-3. I actually own a pair. They are efficient while being balanced. As soon as you finish that design I'd like to build them as mains for HT duty. So please don't let go of the TMM. If you do a TM that would make for a wicked surround or even a stand mount main.

Dan

[TN Allen]

TNA,

I'd definitely take you up on it if I had the measurement capability. I would also like to get this info out to those that can use it. I was going to foot the freight to Mark K so he could measure and design. I wish I could be more help on this. I'm not sure how tight Pete's time is but I guess could order some baffles from the new CNC source and have them sent to Pete so he could get the ball rolling. Another option might be to have you fab the guides and I could do the rest of the work necessary to build the baffle but that would require 3 people to be involved in shipping/fabricating something instead of just two if I were to get them CNC'd.

I'm open to whatever gets the job done. Just tossing out ideas.

OK. Decide what wood you would like, and as I wrote, if I have it I'll turn guides in it. Otherwise, I'll use what I have. I know the guide configuration Pete used was discussed in an earlier thread, and I know I developed the geometry to check the dimensions and I think found the radius was closer to 3.95", I need to check this. As I recall, 3.953" worked in order to have the radius tangent to the baffle face on a 8.5" diameter, using a 1.625" throat diameter and 2" thickness. I'll turn whatever radius you choose, but we need to decide.

The guides I've turned have a rabbet turned on the back to fit into a similar rabbet in the baffle, will this also work for you. Perhaps I should send you an image of the guide and geometry.

[Erich H]

There's a possibility I'm going to do another plastic product this year. If you guys think it will pay for itself, I believe they could carve your waveguide into the mold next to the project I'm trying to get done. I bet the end cost would be around $10 - $15 if they could simply add in yours next to what I'm hoping to get done. Obviously I'm not 100% sure, but could certainly find out.

If someone could also design an adapter for a couple different tweeters, maybe that could be done too. Then one waveguide could be used for multiple tweeter models.

[theLinks]

That sounds like a good deal, I'm in!
Tim

[Pete Schumacher ®]

There's a possibility I'm going to do another plastic product this year. If you guys think it will pay for itself, I believe they could carve your waveguide into the mold next to the project I'm trying to get done. I bet the end cost would be around $10 - $15 if they could simply add in yours next to what I'm hoping to get done. Obviously I'm not 100% sure, but could certainly find out.

If someone could also design an adapter for a couple different tweeters, maybe that could be done too. Then one waveguide could be used for multiple tweeter models.

That would be great to see. This particular profile produces some of the most consistent off axis plots I've seen to date. The EQ circuit is a bit more complex in that a single cap won't work like it does in conical profiles guides.

We built an adapter for it that allowed us to use the smaller diameter T-lab tweeter. It was simply a conical section, 1/2" thick, with the same 60 degree exit angle that the guide starts with at the opening. That brought the opening down to 1" diameter, a perfect match to the 26mm T-lab. The only penalty was a "bump" in the response at just above cutoff, easily accommodated in the XO.

[arlis_1957@yahoo.com]

There's a possibility I'm going to do another plastic product this year. If you guys think it will pay for itself, I believe they could carve your waveguide into the mold next to the project I'm trying to get done. I bet the end cost would be around $10 - $15 if they could simply add in yours next to what I'm hoping to get done. Obviously I'm not 100% sure, but could certainly find out.

If someone could also design an adapter for a couple different tweeters, maybe that could be done too. Then one waveguide could be used for multiple tweeter models.

im in too.. thanks for the interest.

[Face]

There's a possibility I'm going to do another plastic product this year. If you guys think it will pay for itself, I believe they could carve your waveguide into the mold next to the project I'm trying to get done. I bet the end cost would be around $10 - $15 if they could simply add in yours next to what I'm hoping to get done. Obviously I'm not 100% sure, but could certainly find out.<br />
<br />
If someone could also design an adapter for a couple different tweeters, maybe that could be done too. Then one waveguide could be used for multiple tweeter models.

That would do well!

[Erich H]

If anyone gets a really nice end product that they'd consider 100% finished, then I have no problems getting things priced out.