Questions regarding RS28a and 3" flared port

[MOState]

This coming weekend im going to be finishing my coffee table/sub. All I have left to do is paint. While I am home, I will also take on the challenge of building the cabinets for some Nat Ps. The problem is I am a college student without the funds of buying any of the electronics. I won't be buying the port either so I can just order everything at once. So...I don't have anything to physically measure to base my cuts off of.

So, last night I prepared my cut list as well as the diagrams and such. I just have a couple of questions:

Regarding the RS28A:
1) What is the thickness of the flange? I want to get all of this cut out while I am at my parents house and have the tools, seeing as how its not a short trip. I found something by searching for the thickness of the RS180 already, but nothing on the tweeter.

2) I have found contradictory info on the size of the cutout for the tweet. The initial post in the Natalie P thread states 3" diameter. Parts Express says 3.25". Im assuming I will go with PE on this...but just incase its a typo...

3) The picture of the actual box in the Nat P thread shows 2 notches in the hole for the tweeter. Can I assume thats for the leads?

Regarding the Flared Port:
1) Since this port is flared (obviously), what size hole needs to be cut for it to fit?

One last question:
I plan on making this out of some 3/4" oak ply from lowes or home depot. For anyone who has used this...does it chip easily...or should I ask, is it prone to chipping? Does the chipping decrease when cutting with the grain vs. against?

Thanks,
Shaun

[ThomasW]

It's really best to have the parts in hand when doing fabrication.

If Jon's CAD drawing says 3" that's what I'd use.

There is one notch and both tweeter leads go through it.



The instructions talk about using a 3" straight port for a larger box, or 2" flared port for the PE sized box

http://www.psp-inc.com/psp-inc.com/public_html/instructions.htm

One could write a book about techniques for cutting pre-veneered ply, and working with it is not a job for n00bs. If you've never worked with it I strongly suggest veneering after the box is assembled.

[DeanP]

I can only help with the plywood aspect!
This stuff doesn't like cross cutting. The best way is to put the oak side down, on top of another piece of wood. This will help in it not splintering. So, just to make sure I'm explaining good,its saw table top, then scrap plywood(mdf works best),then the oak plywood with the oak side down.

[MOState]

It's really best to have the parts in hand when doing fabrication.

If Jon's CAD drawing says 3" that's what I'd use.

There is one notch and both tweeter leads go through it.



The instruction talk about using a 3" straight port for a larger box, or 2" flared port for the PE sized box

http://www.psp-inc.com/psp-inc.com/p...structions.htm

It may be months before I can afford the electronics, because for whatever reason noone is hiring now. More than likely months after THAT before I have the time to go to my parents house and actually build it. Im not doing the complete assembly, I just want to get as much done as I can, while I have the time.

I guess I missed the 3" straight vs 2" flared in all the reading. I was basing a great deal of my towers from soundbite's design, in which he used a 3" flared. If I were to use a flared, any idea on the size of the cutout?

[MOState]

I can only help with the plywood aspect!
This stuff doesn't like cross cutting. The best way is to put the oak side down, on top of another piece of wood. This will help in it not splintering. So, just to make sure I'm explaining good,its saw table top, then scrap plywood(mdf works best),then the oak plywood with the oak side down.

So make an oak sandwich basically. That may be difficult if using a table saw though.

[ThomasW]

You might want to call or email PSP to get that info

[Gir]

I just finished up an RS225/RS28A 2-way, and I'll have it up here by next week (I too am in college and it's currently sitting at my parents house). I can give you the measurements for the RS28A by next friday if that's not too late.

[MOState]

I just finished up an RS225/RS28A 2-way, and I'll have it up here by next week (I too am in college and it's currently sitting at my parents house). I can give you the measurements for the RS28A by next friday if that's not too late.

That would be great, thanks.

[wkhanna]

I am just putting the very last finishing details on a set of Nat P's, so I just took out the RS28A to make some measurements for you.
Flange thickness is .135" or just over 1/8" by about the three hairs.
Diameter is just under 4.125", so a 4-1/8 diameter routed recess should be about right.

I waited till I had my drivers 'in hand' so I could test-fit, though.

It has been suggested to put a very light coat of silicone on the flange to act as an air-tight seal, and this will add a V small amount ot flange thickness if you go this rout.

Good luck, and don't hesitate to ask questions.

[MOState]

I am just putting the very last finishing details on a set of Nat P's, so I just took out the RS28A to make some measurements for you.
Flange thickness is .135" or just over 1/8" by about the three hairs.
Diameter is just under 4.125", so a 4-1/8 diameter routed recess should be about right.

I waited till I had my drivers 'in hand' so I could test-fit, though.

It has been suggested to put a very light coat of silicone on the flange to act as an air-tight seal, and this will add a V small amount ot flange thickness if you go this rout.

Good luck, and don't hesitate to ask questions.

Thats exactly what I was lookin for. Thank you

[jbateman]

If you are using the 2" flared port, you cut a 4.25" hole. This will allow you to insert the assembled port from the rear, and remove it if necessary without having to get inside the box.

Don't know the dimension on the 3" flared port, though.

[wkhanna]

IIt has been suggested to put a very light coat of silicone on the flange to act as an air-tight seal, and this will add a V small amount ot flange thickness if you go this rout.

Just want to clarify; the silicone was recommended to be applied to the cabinet surface of the recess, not the flange of the driver.

[JonP]

If you are using the 2" flared port, you cut a 4.25" hole. This will allow you to insert the assembled port from the rear, and remove it if necessary without having to get inside the box.

Don't know the dimension on the 3" flared port, though.

Hmmm, just happen to have notes handy here at work...

For the RS28, I measured .145" (probably included the gasket, with a squeeze) That came out pretty well once tightened down. I drilled a 3" thru hole, and it probably took 1/4" notches for clearance, but you can do that later when you have the driver.

For the 2" Precision Port, (which I flush mounted.. looks much nicer!) I cut a 5.25" rabbet .125" deep. I used a 4 1/16" thru hole, for a press fit, but really it dosen't need one and can be bigger than that. I also wouldn't know if the 3" port has a thicker flange.

Now, after all that... I'd reccomend ignoring it, waiting till you have your parts in hand, and measure with your calipers 4 times and cut once, hopefully!!! :W

[JonMarsh]

Now, after all that... I'd reccomend ignoring it, waiting till you have your parts in hand, and measure with your calipers 4 times and cut once, hopefully!!! :W

Good notes form Jon, but I have to really agree with having the parts in hand- that way if you slip a digit or a measurement, you can check and tell really quick...

[jquin]

I've taken to relying heavily on 3D CAD for modelling speakers before construction.

I'd be lying if I said it was time saving but it's a bit of a passion for me so I do it anyway.

However if you use a package like Solidworks you can construct the model the same way you would fabricate it.
This is basically a full dress rehearsal before you make a single cut.

If someone else here shares a 3D model of the port you could easily see just what cut to make.

It is extremely helpful for new designs because it forces you to sort out all the issues and design something that could be fabricated.
This is not such a big thing if you are copying proven designs posted here, like most of use newbies.

Anyway making 3D models of all the parts like RS??? drivers and ports can be really useful to share for others.

I will soon (end of may) have 3D models of the SS6600, RS180, RS225 & RS28A if anyone wants them.

Bear in mind the cost of the software, unless euphemistically speaking you are going to do one of those "unlimited evaluation" deals it could get expensive.
I am fortunate enough to have access at work.

Regards
John Q

[JonP]

Haven't heard of any Solidworks models, (not to say they're not out there) but there are a few Google Sketchup models in their "warehouse". Not the most accurately dimensioned things either... but Sketchup is free.

I keep hearing of Alibre (sp?) as a near Solidworks clone, easy to use, and has a reasonable $99 version out there. Still haven't downloaded the demo...

[JonMarsh]

I've taken to relying heavily on 3D CAD for modelling speakers before construction.

I'd be lying if I said it was time saving but it's a bit of a passion for me so I do it anyway.

However if you use a package like Solidworks you can construct the model the same way you would fabricate it.
This is basically a full dress rehearsal before you make a single cut.

If someone else here shares a 3D model of the port you could easily see just what cut to make.

It is extremely helpful for new designs because it forces you to sort out all the issues and design something that could be fabricated.
This is not such a big thing if you are copying proven designs posted here, like most of use newbies.

Anyway making 3D models of all the parts like RS??? drivers and ports can be really useful to share for others.

I will soon (end of may) have 3D models of the SS6600, RS180, RS225 & RS28A if anyone wants them.

Bear in mind the cost of the software, unless euphemistically speaking you are going to do one of those "unlimited evaluation" deals it could get expensive.
I am fortunate enough to have access at work.

Regards
John Q

Quite true, but it is time consuming...

I used AutoCAD a long long time for speaker design, but last year started using Concepts Unlimited 3D. It can export ACIS models, solid works and AutoCAD can read them. But sometimes I create 3D models that are quite valid for the enclosure and drivers, but check everything else as I go along in the production process- especilaly if I don't have all the stuff on hand to measure while conceptuallizing the design.

Unfortunately, due to this being a time consuming hobby, and time being a diminishing resource (haven't had a day off in weeks), not everything get's done with the procedural rigor I would like...

~jon

[Dennis H]

not everything get's done with the procedural rigor I would like...

Chuckle, my idea of cabinet rigor is a sketch on a napkin. Or maybe the backside of a piece of used printer paper. I can cut wood faster than I can do 3D CAD and I did CAD for a living for a while. Of course it helps to have a basic 3D image in mind as you measure and cut to fit as you go.