Ambitious cabinet design for Nat P!

[Coconutout]

oh god this is almost too much... ;x( :P

[Johnnz]

access panels and binding post assembly

oh god this is almost too much... ;x( :P

hehe, :lol:

From last nights effort, here are some more photos:

Got the domes from a sewing shop in the end, a lot cheaper than buying a whole second hand jacket as it turns out:



One speaker with access panel and binding post wrapped in leather and attached, the other laying out in parts on the bench:



Close ups:

[Hdale85]

That looks fantastic.

[cjd]

I often wonder if I would take the time to do work this nice if I had a proper shop, not a temporary-take-over-of-the-garage ...

keep the pics coming!

C

[Johnnz]

Access hatch

Got a delivery today of T-nuts and bolts etc for the access hatch and Xover attachment. Got the 5mm T-nuts installed today for the access hatch but will wait until I have finalized the location of all components on the crossover board before I install the 4mm T-nuts into them (giving priority to components and solder lugs since it will be a tight fit to get everything on there (150mm x 175mm) Then I will use countersunk bolts beneath the access hatches to secure the X-overs in place.

Unfortunately, although it has now been 4 months since I placed my order with a local (NZ) supplier of speaker parts, I am still waiting for some crossover components that were missing in my order. Also waiting on a tweeter (one got broken in the warehouse apparently...) Not very happy about this situation at all. Not much more I can do until I know the exact size of all components so I can decide where the solder lugs will go that I will rivet in to the 5mm hardboard. Looks like I will be making blackboards for my wife's restaurant tomorrow instead... been putting those off for a while now...

Crossover components roughly laid out on boards:



Access panel test fitted and fastened into position:



Note the tight fit for the X-over between access hatch and port pipe! Should be fine though after testing with a block same size as finished Xover:

[Johnnz]

Thinking about the above brings me to wonder, what if the second tweeter is not a matched pair? I notice the one i have has some numbers printed or stamped on it - dB? How important is their matching? Can I compensate by altering one crossover if there is a difference, or is this a negligible factor?
Thanks

[fbov]

This is a very real issue if you're purchases are widely spaced. I have 2 RS28a's purchased ~2.5 years apart that differ in marked sensitivity by over 1dB. It's real, I can hear it and it shows up in FR measurements comparing the two speakers. A stopgap suggested by Jeff Bagby was to put a 10ohm resistor across the hot tweeter to bleed off some power. This got my FR curves closer together, and they sounded very good, but....

I've since bought parts for a second pair of NatP's (sealed, unshielded, silk dome this time), and while building boxes thought I'd throw the new RS28F's in to replace the mismatched 28A's - it's now better than very good, it's the way I remember it should be (assuming falsely that my opinons are purely objective).

Now I'm looking for the match to one of mine. Why one old one? My first build was a CC so that's all I needed.

Have fun,
Frank

[Johnnz]

This is a very real issue if you're purchases are widely spaced. I have 2 RS28a's purchased ~2.5 years apart that differ in marked sensitivity by over 1dB. It's real, I can hear it and it shows up in FR measurements comparing the two speakers. A stopgap suggested by Jeff Bagby was to put a 10ohm resistor across the hot tweeter to bleed off some power. This got my FR curves closer together, and they sounded very good, but....

I've since bought parts for a second pair of NatP's (sealed, unshielded, silk dome this time), and while building boxes thought I'd throw the new RS28F's in to replace the mismatched 28A's - it's now better than very good, it's the way I remember it should be (assuming falsely that my opinons are purely objective).

Now I'm looking for the match to one of mine. Why one old one? My first build was a CC so that's all I needed.

Have fun,
Frank

If you change to using the nicer 28f's is it necessary to alter the crossover?

[cjd]

Everything I've seen/tested suggests the RS28A and RS28F are largely interchangeable. Sensitivity differences are the biggest issue - the mild rising top end on the F vs the small dip on the A (and potential compensation) being second on that list.

[Johnnz]

I may look into those tweeters, but I am really hoping it won't come to that. Shipping from the States is really expensive to NZ so i hope my parts supplier here will pull through with the goods... As an example, today I ordered veneering supplies from Joe Woodworker in the States - shipping was a good ten percent more than the total cost of the items I had in my cart - Ouch :E 8O .

Anyway, been working on the crossovers today, got one almost done less the two missing capacitors and hook up wire (hoping to get some short lengths tomorrow from a local hifi shop). I will install solder terminals onto the back of the board so once the X-over is mounted the speakers can be wired up.

Bare boards with mounting hardware and solder lugs fitted:



Almost done - all components are hot glued to the board with the inductors also cable tied in around board as well:

[fbov]

Everything I've seen/tested suggests the RS28A and RS28F are largely interchangeable. Sensitivity differences are the biggest issue - the mild rising top end on the F vs the small dip on the A (and potential compensation) being second on that list.

When I did the swap of sensitivity-compensated A's for F's, what I noticed was the speakers now sounded the same, but not all that different from before. Granted, my 56 year old ears are dead above 14KHz, so the primary FR diffferences are beyond my hearing range, and I know what I did, so physhologicals are going to favor the change. I could be fooling myself....

Note that R3 is the padding resistor in the NatP XO. My first pair of NatP's(shielded, 28A) were purchased within a few months of my 90.4dB RS28A, and they sound very well balanced with the 0.47ohm in place. If I end up using current stock, I plan to reduce or remove R3. You should consider it, too.

Ah, I only see 2 resistors... no R3.

HAve fun,
Frank

[Johnnz]

R3 is there, just hidden between two capacitors. Got both done as far as I can go now. Can't think of anything else to do now apart from gluing up the cabinets but might get some more sash clamps before I start that procedure.

[Owen Bartley]

Everything I've ever built is fiercely jealous of these cabinets already; and they're not even finished.

I have to agree. John, these are coming along very nicely, and they are definitely near the top of the list of my favourite projects in the DIY areas. Keep up the great work!

[BeerParty]

Almost done - all components are hot glued to the board with the inductors also cable tied in around board as well

So, are you planning to mount the crossovers externally to show off your excellent work here? Just kidding, I know you are planning to mount them internally.

It's too bad really, that work is worthy of an external box with a plexiglass window. And I hate boxes with plexiglass windows.

This is a fantastic build, thank you for sharing with us. :T

[Renovator]

I may look into those tweeters, but I am really hoping it won't come to that. Shipping from the States is really expensive to NZ so i hope my parts supplier here will pull through with the goods... As an example, today I ordered veneering supplies from Joe Woodworker in the States - shipping was a good ten percent more than the total cost of the items I had in my cart - Ouch :E 8O .

Have to agree with the part about the shipping. Last thing I bought was the drivers for the Nano's on Parts Express forum. ( think --k-- posted his build here?) Was supposed to be a cheap speaker. Freight was the same price as drivers and crossover component cost

Then add the exchange rate and the idea of cheap goes out the window.

Never mind. As people often advise - I'm not here to save money.

Lewis

[Johnnz]

I have been informed that my missing tweeter and other bits are due to arrive on Monday. Not sure where they are meant to be arriving but here's hoping it's my place... ;h

Anyway, have just glued up one cabinet after an extremely frantic 25 minutes. An extra pair of hands might have been helpful, but had everything assembled and glued after 15 minutes. Unfortunately, I cranked up the long sash clamps prior to putting tension on the sharp corners of the four triangular pieces with the F clamps, consequently they tended to slip inside, so another frantic 10 minutes was spent reversing that as much as possible. A few small gaps remain, but with 9 biscuits top and bottom there is plenty of strength and a bit of gap filling will never be noticed after veneering over the top. Overall, not much of a biggie, though it put a bit of adrenaline into the bloodstream at the time!

Other good news, my veneering supplies arrived from the States (Joe Woodworker) within a week, so was very impressed there.

[Johnnz]

The learning curve kicked in rapidly for the second cabinet. This one went together perfectly. Mainly due to tightening the F clamps first. Got a bit more glue in this time and either side of the biscuits too so it's oozing out along all the joins nicely.

[wkhanna]

To quote Sir ThomasW's kind and encouraging comment during my build:

Progress is our most important product..... :W

[Txgrizzly]

very nice, cant wait to see them finished... question: with the angles what type of finish are you putting on them? i can see where doing veneer would be difficult

[Johnnz]

Thanks. I intend to veneer them using an iron and HeatLock glue I got from Veneersupplies. I also got some veneer conditioner that makes the veneer extremely pliable so this should help for the sides where I will use one big sheet. The rear has a little angled step in it which I will probably do in three parts.
I am just a bit worried that the conditioner might cause the paper tape joins to fail on the wide sheet I need to use on the sides. I will find out shortly... but I will start by only spraying the bottom of the veneer so the tape isn't directly wetted.

Gluing on the rear panels and packer:

[Hdale85]

I am LOVING those cabinets. I'm not sure I could accomplish something like that......boy would I love to though.

[bbcmp1979]

Very nice build, I love the craftmanship :-)

[cjd]

Yeahp. Uh huh. If I had a studio and could leave projects going, I'd start work like this!

Would I finish it?

errrrr.

Looking awesome. I love seeing stuff like this take shape.

[Johnnz]

Thanks for the comments.

Got my sheets of cherry wood veneer out on the bench today and sorted out which sheets to use on which faces. I gave a sample piece a good soaking spray both sides of veneer conditioner, but it turns out I was being a little unrealistic in thinking that it could make straight grained cherry wood as supple as a burr veneer that is shown in the products website being rolled up into a cigar sized tube.

I will do more experimentation tomorrow with a hot steam iron to see if that can convince the veneer to fold around the angle on the sides (195 degrees measured from outside). If that fails (meaning I want a nice sharp fold as opposed to a soft curve around those edges) then I will have to probably cut the veneer and see how carefully I can glue the pieces back together at the join. I think that as far as shrinkage goes while ironing, it will be minimal with the grain (up and down the line of the grain). But I will have to test to confirm. Another difficulty if cutting the veneers will be that the edges on the cabinet are not dead straight anymore since sanding them...

Latest word on missing tweeter and Xover parts: "Shipment delayed. Now due in the country on Saturday..." :gah:



Ready for veneering (baffle sat on top)

[john trials]

I'm not sure about Heatlock, but when I used cherry veneer and the iron method (with Titebond glue), the Titebond really softened up the veneer. On a dry fit, the veneer cracked when wrapped around a 3/4" radius. Once the Titebond was applied to the back of the veneer (and had dried) the veneer was much more flexible. The heat from the iron (dry, not steam) helped, too. Try a test piece of veneer with the Heatlock.

[repeet]

Latest word on missing tweeter and Xover parts: "Shipment delayed. Now due in the country on Saturday..."

I must add after dealing with the same NZ company, HAS Audio, that they certainly aren't the most professional company to deal with.
It took 9 weeks for delivery of my mini statements parts that they said would take 9 days with the same excuses that I here you posting about.
I stupidly placed another small order for a circle jig with them that took 3 weeks instead of 1 week. It finally arrived with a postage date 2 weeks after the order was placed and a tracking number which I had previously asked for and they denied having. They said they would refund my money for my troubles, which they never refunded and then asked if I could send the part back.
I'm sorry that this is my first post on this forum but feel that a warning about dealing with this company must be made.

[Hdale85]

Heat lock does the same thing from what I remember. I don't think you're supposed to use a steam setting though? Not entirely sure but I don't believe I did.

[Txgrizzly]

Thanks for the comments.

Got my sheets of cherry wood veneer out on the bench today and sorted out which sheets to use on which faces. I gave a sample piece a good soaking spray both sides of veneer conditioner, but it turns out I was being a little unrealistic in thinking that it could make straight grained cherry wood as supple as a burr veneer that is shown in the products website being rolled up into a cigar sized tube.

I will do more experimentation tomorrow with a hot steam iron to see if that can convince the veneer to fold around the angle on the sides (195 degrees measured from outside). If that fails (meaning I want a nice sharp fold as opposed to a soft curve around those edges) then I will have to probably cut the veneer and see how carefully I can glue the pieces back together at the join. I think that as far as shrinkage goes while ironing, it will be minimal with the grain (up and down the line of the grain). But I will have to test to confirm. Another difficulty if cutting the veneers will be that the edges on the cabinet are not dead straight anymore since sanding them...

Latest word on missing tweeter and Xover parts: "Shipment delayed. Now due in the country on Saturday..." :gah:

Ready for veneering (baffle sat on top)

If you are unable to get the veneer to go the way you want i vote for a high gloss automotive style finish in a metallic gray color... ^_^ :T

[Johnnz]

Well, I think I have got a good result using the iron to bend the veneer around the edge with glue on. Just about to start on the cabinets.





Holes plugged, ready for gluing:

[Johnnz]

Ironed on:



Trimming:



Re-exposing holes:



Bottoms done:

[Txgrizzly]

great start... really looking forward to see these finished.

[Johnnz]

Finally got all the veneering done. That turned out to be a intensive headache inducing task! All done now, a couple of little splits but I hope that the Heatlock glue will hold them where they are with the power of its "crosslinking polymers"! I discovered that it does pay to preshrink the veneers by lightly ironing them prior to gluing. Also I ended up taping the all the end grains prior to ironing into position.

Now onto spraying laquer etc!

Mock up with base

[fbov]

I'm looking at this speaker that's floating in air against a wall...

Then I notice the shelves in the background, and nothing's sliding off....

Great results in reality, but that initial image was even better!

HAve fun,
Frank

[JonP]

Just WOW....

They're looking even better than I thought they wood, uh, would.

And not even stained and finished yet! :T

[Johnnz]

Thanks.

Just about ready to spray now. Will use Sanding Sealer followed by a couple coats of lacquer.

Have just received an email that states my missing parts have been forwarded on to me so this entire project should be over within a few days now. Got some nice offcuts of "solid long grain copper" Audioquest speaker cable from a local hifi shop to wire up the internals with today too. Only a bit concerned however that solid copper wiring on the internals could be a bad thing given the vibrations it will be subject to and the risk of metal fatigue?

The bottom firing ports come in handy now for raising the cabinets up on spikes for spraying:

[Txgrizzly]

Thanks.

Just about ready to spray now. Will use Sanding Sealer followed by a couple coats of lacquer.

Have just received an email that states my missing parts have been forwarded on to me so this entire project should be over within a few days now. Got some nice offcuts of "solid long grain copper" Audioquest speaker cable from a local hifi shop to wire up the internals with today too. Only a bit concerned however that solid copper wiring on the internals could be a bad thing given the vibrations it will be subject to and the risk of metal fatigue?

The bottom firing ports come in handy now for raising the cabinets up on spikes for spraying:

make sure you let us know what type of rig you are shooting the lacquer with

[JonMarsh]

Thanks.

Just about ready to spray now. Will use Sanding Sealer followed by a couple coats of lacquer.

Have just received an email that states my missing parts have been forwarded on to me so this entire project should be over within a few days now. Got some nice offcuts of "solid long grain copper" Audioquest speaker cable from a local hifi shop to wire up the internals with today too. Only a bit concerned however that solid copper wiring on the internals could be a bad thing given the vibrations it will be subject to and the risk of metal fatigue?

The bottom firing ports come in handy now for raising the cabinets up on spikes for spraying:

Just about the moment of truth! Great progress- :T I'm jealous!

[Hdale85]

Just about the moment of truth! Great progress- :T I'm jealous!

That coming from Jon says A LOT.

[Johnnz]

Thanks Jon. Being a bit of a newbie around here, I am not sure, but have a feeling that you are the actual designer of this speaker configuration? Albeit in an alter ego perhaps?? If so, thank you for your encouragement and for sharing your work.

I have yet to wire these up to listen to yet. I am still short of a tweeter, some caps etc., but have been assured in the last few days that after 4 months these parts are finally on the last leg of their journey to me. If so, it will be just in the nick of time to not delay me getting to listen to them.

I have now finished lacquering (really amazing dry time in the sanding sealer and lacquer - 30 minutes between sanding/recoat!) Will put up some photos of the gear I used shortly.

I have listed my current speakers (Mission M71 bookshelf type) and amp on our Ebay equivalent, and am hoping to sell them for a good price so I can get a more powerful amp. I am selling my Rotel 930AX (30W at 8ohm) and am hoping to buy a Audiolab 8000S (60W at 8ohm). If I still have the Rotel when I bring the speakers in to listen to do you think I would be OK to run them safely? As far as I understand I should be safe as long as not cranking up so loud to get any clipping.

Thanks!

[Johnnz]

Still waiting for final pieces to arrive in the mail, expecting they should be here on Monday as I actually have a tracking number now...

Have got all wiring done on the X-overs now. Used the Audioquest cable for them and bought some more flexi cable for the leads going to the drivers. Putting the solder tabs on the back will make for easy access to remove the X-overs if need be in the future.

Also got the holes drilled in the baffles with a circle jig fastened in with a screw to a slat behind the baffle.

[oldbar]

Latest word on missing tweeter and Xover parts: "Shipment delayed. Now due in the country on Saturday..."

I must add after dealing with the same NZ company, HAS Audio, that they certainly aren't the most professional company to deal with.
It took 9 weeks for delivery of my mini statements parts that they said would take 9 days with the same excuses that I here you posting about.
I stupidly placed another small order for a circle jig with them that took 3 weeks instead of 1 week. It finally arrived with a postage date 2 weeks after the order was placed and a tracking number which I had previously asked for and they denied having. They said they would refund my money for my troubles, which they never refunded and then asked if I could send the part back.
I'm sorry that this is my first post on this forum but feel that a warning about dealing with this company must be made.

You are not the only one having problems with the company you are talking about ....
I normally buy from Madison but the prices were to good to pass up since i live in Australia.....So far they have been terrible to deal with

[repeet]

:evil:

[Johnnz]

Well, I just received the remainder of parts that were missing from my original order - 5 months after I placed my order, but then I guess it has taken me as long to get the cabinets done anyway The supplier included some solid looking Dayton spikes (though I already have a set) and a 50w Dayton mini amp... At least coming through with the goods is better than leaving me in the lurch...

Watch this space for a completed set of Nat Ps...

[Hdale85]

Are they done yet :B

[serioushifi]

You are not the only one having problems with the company you are talking about ....
I normally buy from Madison but the prices were to good to pass up since i live in Australia.....So far they have been terrible to deal with

If you used the free shipping deal(which most people do), what do you expect? So many people complain about shipping costs from the USA. So they use a postal service which with hasaudio is FREE at a certain order price. When something goes wrong or delivery times get thrown out the window which can easily happen, guess who gets the blame? If you were charged what you would pay for shipping via fedex,dhl etc, then you would have reason to complain.

With regards the nat P order. Not much to say really about that one. Mistakes were made, bits weren't ordered when they were meant to be, bits were broken during shipping. But no more. Not doing special orders anymore. If we don't have it, buy overseas.

We try our best.