Nubie's Build - The Copper Project

[tubetrek]

Re: Nubie's Build - The Copper Project

Nub,
I'm also working on a copper build. Here's a mod I did, maybe useless. I defer to the experts here.

The 1685 is really crammed against the lower shelf. To increase driver breathing, I routed 1/2" out of the shelf from the area adjacent to the woofer. That hole-like mark is actually burning. Router speed and handling is an art-form.
Dave H
Chambersburg, PA

Dave,
WOW, my chamfering effort is about 1/4 of yours. Hope someone can chime in and tell us how much is adequate. Will take a photo of mine.

Also thanks for the heads up re: stuffing

FYI, there's a chance those posts are not sized to fit that plate.

Thanks Ben, I did see that discrepancy after doing some research on that plate. Gonna just stick with my original binding posts for now.

Currently in the process of staining, bought two stains, but ultimately will probably condition the wood then poly. The end is in sight.

Ted

[Dave Hartwick]

Re: Nubie's Build - The Copper Project

Dave,
WOW, my chamfering effort is about 1/4 of yours. Hope someone can chime in and tell us how much is adequate. Will take a photo of mine.

Ted

That is a standard 45 deg chamfer that extends all the way through 1.5" of MDF. This obviously reveals a lot of raw real estate. Probably over kill. Paul and Marty?

There's an easier way to do this, but I used a rotary rasp to remove most of the material. I could have done most of this with a 45 deg router bit, but forgot, glued the panels and then it was too late.

Actually, with double thickness baffles like this, I usually first cut the inner main panel's hole with a jigsaw set to 45, the diameter of which being calculated to meet the outer panel's chamfer flush (more or less!).
Dave
(Hope I'm not hijacking your build thread.)

[Dave Hartwick]

Re: Nubie's Build - The Copper Project

For what it's worth, my xover. Warning: That P-core inductor may be fragile, unless I got a lemon. The end of one just fell off into my hand. A Clean break made for successful CA gel gluing. (Jeez! ...I should measure the inductance.)

Anyway, those inductors will be blocked firmly to the board.

Finally, do guys have a favorite wire for internal speaker duty. When in doubt, I use appropriately sized magnet. Vintage stuff that may be 50 years old.

Oh yes! What's the best wood filler these days. I see Bondo in use here. Others?

Dave

[tubetrek]

Re: Nubie's Build - The Copper Project

That is a standard 45 deg chamfer that extends all the way through 1.5" of MDF. This obviously reveals a lot of raw real estate. Probably over kill. Paul and Marty?

There's an easier way to do this, but I used a rotary rasp to remove most of the material. I could have done most of this with a 45 deg router bit, but forgot, glued the panels and then it was too late.

Actually, with double thickness baffles like this, I usually first cut the inner main panel's hole with a jigsaw set to 45, the diameter of which being calculated to meet the outer panel's chamfer flush (more or less!).
Dave
(Hope I'm not hijacking your build thread.)

Dave,

when I hooked everything up for a listen, they sounded great (with my current chamfering dimensions), but you got me thinking. Perhaps I should do some more on one baffle and see if there is a dramatic difference? But then again I'm probably not experienced enough to hear a difference if there was one.:(

as for filler, I use the elmers wood putty and for me it's easily sandable and have fixed numerous router blunders on this project.

Ted

[martyh]

Re: Nubie's Build - The Copper Project

That is a standard 45 deg chamfer that extends all the way through 1.5" of MDF. This obviously reveals a lot of raw real estate. Probably over kill. Paul and Marty?

There's an easier way to do this, but I used a rotary rasp to remove most of the material. I could have done most of this with a 45 deg router bit, but forgot, glued the panels and then it was too late.

Actually, with double thickness baffles like this, I usually first cut the inner main panel's hole with a jigsaw set to 45, the diameter of which being calculated to meet the outer panel's chamfer flush (more or less!).
Dave
(Hope I'm not hijacking your build thread.)

Hey Guys,

Just so you know Paul hasn't built this design and as far as I know has only heard my Iowa 2009 version.

It's fair to say that any additional breathing room made available for a driver is a bonus, so chamfering out that material is a good idea. But remember, if you placed that divider board correctly you shouldn't have any clearance issues and a 45 degree chamfer on the backside of the cut-out will be more than adequate breathing room.

Good Luck.

[Dave Hartwick]

Re: Nubie's Build - The Copper Project

Dave,

when I hooked everything up for a listen, they sounded great (with my current chamfering dimensions), but you got me thinking. Perhaps I should do some more on one baffle and see if there is a dramatic difference? But then again I'm probably not experienced enough to hear a difference if there was one.:(

as for filler, I use the elmers wood putty and for me it's easily sandable and have fixed numerous router blunders on this project.

Ted

Ted,
I'm sure Marty and/or Paul well chime in here and I would wait for their advice.

You see, I go to excess on everything. Since you're reporting great sound, you probably have adequate breathing room. It's good news for both of us and all Copper guys that your work has been rewarded!

Elmer's: Did you use it to deal with that nasty MDF end-grain? Sealing...

I'm curious -- With what are you driving your speakers?

Dave

[tubetrek]

Re: Nubie's Build - The Copper Project

Ted,
Elmer's: Did you use it to deal with that nasty MDF end-grain? Sealing...

I'm curious -- With what are you driving your speakers?

Dave

No I used the Elmer's just for all the big time errors I made with the router. Also on some cuts that weren't exactly 90 degrees (due to my circular saw, hopefully my newly purchased table saw will make life easier). As for endgrain, I really didn't specifically address it since I used veneer with the coldpress method which in theory would work like the 50/50 titebond sealing.

So far I don't see any indication of endgrain through the veneer.

As for running the speakers, my main amp is a 25 watt Dynaco ST-70 moded with the VTA driver board. I also tested it with a solid state AMC 2445 amp (90 watt/ch).

Finished poly and just waiting for it to dry and then onto assembly and enjoyment!

Ted

[martyh]

Re: Nubie's Build - The Copper Project

Guys, I went back into my in-home pair and am going to recommend that you don't chamfer out any material on the enclosure divider board. The advantages of that little bit of extra breathing room are in conflict with the slight, but potentially significant change in the cabinet volume. Yes I know we're only talking 6 cubic inches give or take, but it's Pauls design and he used some pretty sophisticated mathematics. Any changes beyond chamfering the cut-out could impact the port length and the length of the divider line.

The short version: No need to tempt the fates here!

Marty

[tubetrek]

Re: Nubie's Build - The Copper Project

Guys, I went back into my in-home pair and am going to recommend that you don't chamfer out any material on the enclosure divider board. The advantages of that little bit of extra breathing room are in conflict with the slight, but potentially significant change in the cabinet volume. Yes I know we're only talking 6 cubic inches give or take, but it's Pauls design and he used some pretty sophisticated mathematics. Any changes beyond chamfering the cut-out could impact the port length and the length of the divider line.

The short version: No need to tempt the fates here!

Marty

After reassembling the baffles with speakers I'll take another look at what type of clearance I have and will follow this suggestion by Paul C on another thread.

So, I suppose a good rule-of-thumb is "if you can't see the backside of the cone, then the cone probably can't see the inside of the cabinet."

I didn't chamfer anything out of the divider board, just on the 2nd piece of MDF behind the driver.

Sanding off the semi-black off the 2nd baffle now and will paint. Hopefully fully functioning speakers by the weekend.

Ted

[Dave Hartwick]

Re: Nubie's Build - The Copper Project

Guys, I went back into my in-home pair and am going to recommend that you don't chamfer out any material on the enclosure divider board. The advantages of that little bit of extra breathing room are in conflict with the slight, but potentially significant change in the cabinet volume. Yes I know we're only talking 6 cubic inches give or take, but it's Pauls design and he used some pretty sophisticated mathematics. Any changes beyond chamfering the cut-out could impact the port length and the length of the divider line.

The short version: No need to tempt the fates here!

Marty

Marty,
By "enclosure divider board", I assume you're referring to the ~26" angled partition? Or is it the shelf just above the driver, out of which I routed ~2 cubic inches? Post #55 http://techtalk.parts-express.com/sh...=222498&page=3

Altering the intended design is obviously a bad idea. But I note with humility that 6 cubic inches represents 0.34% of the 1.02 cu ft design volume. (Don't you hate when someone whips out the calculator and says "BTW, blah, blah...")

Anyway, your general point is well taken.
Dave

[Paul K.]

Re: Nubie's Build - The Copper Project

I didn't want to embarrass Marty and changed my mind about replying with something similar, but since you've already done so, here's what I found out some time ago on this issue in general. I modeled a TL to a more or less optimum point, then changed the volume within the line, without changing anything else, making volume increases in ~1% increments to see how the line's performance was affected. I ended up "drawing a line in the sand" at a 5% change in volume; up to that point the change in performance was not significant enough to warrant compensating for it. This information is particularly useful when one is deciding how to add bracing and how the volume consumed by the bracing will affect performance.
Paul

Marty,
By "enclosure divider board", I assume you're referring to the ~26" angled partition? Or is it the shelf just above the driver, out of which I routed ~2 cubic inches? Post #55 http://techtalk.parts-express.com/sh...=222498&page=3

Altering the intended design is obviously a bad idea. But I note with humility that 6 cubic inches represents 0.34% of the 1.02 cu ft design volume. (Don't you hate when someone whips out the calculator and says "BTW, blah, blah...")

Anyway, your general point is well taken.
Dave

[martyh]

Re: Nubie's Build - The Copper Project

I didn't want to embarrass Marty and changed my mind about replying with something similar, but since you've already done so, here's what I found out some time ago on this issue in general. I modeled a TL to a more or less optimum point, then changed the volume within the line, without changing anything else, making volume increases in ~1% increments to see how the line's performance was affected. I ended up "drawing a line in the sand" at a 5% change in volume; up to that point the change in performance was not significant enough to warrant compensating for it. This information is particularly useful when one is deciding how to add bracing and how the volume consumed by the bracing will affect performance.
Paul

Embarrass me? Nah....a precedent was set against Penn State last night that I could never match. :(

My 6 cubic inches guess was based purely on that photograph, so adjusting the enclosure volume that much would be significant - or so I thought. Your design has worked so well that nobody should mess with it!

[tubetrek]

Re: Nubie's Build - The Copper Project

Nearly DONE!!

After couple layers of poly and sanding


added weather stripping, ready for baffles





Completed "The Copper Project" TA DA!!


just need to decide on speaker spikes


up close detail, veneering on the corners came out pretty nice for a nubie!!


Again, Thanks to Marty, Paul K., "Dirk" for a wonderful sounding and work of art design! :D

On to my next project!

Ted

[DjDisturbed]

Re: Nubie's Build - The Copper Project

Good thing your wife let you paint those that color because they look Awesome. Great job even for someone experienced . If you hadn't told me you were a newb at it I would have never known. Excellent work

[[email protected]]

Re: Nubie's Build - The Copper Project

Good thing your wife let you paint those that color because they look Awesome. Great job even for someone experienced . If you hadn't told me you were a newb at it I would have never known. Excellent work

ditto. how do they sound to you?