Yet another Natalie P

[opt-e]

So I've caught the DIY bug and have decided to build the most excellent Natalie P as ported tower mains in a stereo setup. With all the positive feedback on this design I figure I can't go wrong. Currently, I'm running B&W 600S3's powered by a Rotel RA-01 with a HSU STF-2 sub.

Later on I plan to augmented the system with a sub (or two :T). Depending on how these sound ported I may leave the port open once I have my subs, or seal up the ports if I find they sound better that way. Last summer I helped a friend build a Dayton RSS315HF sub, and just recently I completed a pair of John Krutke's Hivi B3N's as "practice."

The enclosure design. 47.3 L gross internal volume. I will be using two shelf-braces to add rigidity, and 1.5" baffle on the top half of the enclosure only. 3/4" MDF all-round. 3" PVC port with a wide-radius elbum. I bought some PVC from the local hardware store. With a 3" port, is a flare really necessary?



The response. Port tuned to 32hz.



The BOM.



Can anyone see any problems with my design?

Anthony

[Evil Twin]

Your documentation appears to be in order.

For dual 7's in the larger enclosure with this Sd and Xmax, a flared port is advisable. The preferable configuration would be a straight bottom firing 3" flared port, with 1.5" risers front and rear, and the cabinet supported on adjustable points. Bends add resistance and reduce the Q of the tuning. The enclosure volume could be upped to as much as 50-58 liters for greater low end extension if you can work with the larger cabinet. But this is by no means mandatory... merely "suggested". Try those sizes in Unibox and see what you think, and check the plots on port velocity and Xmax. I think 120 watts may be a little over the top in the low end, though as an overall power rating for music it's a good choice.

Otherwise, you plans are most satisfactory.

[opt-e]

Will 1.5" of clearance on the bottom be enough for a 3" port? I've seen recommendations that clearance be at least the diameter of the port.

I realize that port bends will add resistance--but the question is how much and does it make a huge difference? Are there any applications that I can use to model the effect of a port bend?

About the internal volume.. this is about as big as I'm willing to go. I've modelled the larger enclosures and to me the increase in size is not worth the marginal increase in bass response.

[dyazdani]

I realize that port bends will add resistance--but the question is how much and does it make a huge difference? Are there any applications that I can use to model the effect of a port bend?

There are equations to calculate the friction loss through pipe and the elbow, but I have no idea on how that might relate to the box tuning. I suspect that with a 3" pipe, it won't be that big an issue. Maybe one of the smart people here can answer more specifically.

The only thing "wrong" I see in your documents is that MDF normally comes in 49x97 sheets :lol: , at least the ones I buy do...

[opt-e]

The only thing "wrong" I see in your documents is that MDF normally comes in 49x97 sheets :lol: , at least the ones I buy do...

Yeah, just noticed that

[opt-e]

Can someone tell me how big the terminals on the RS180 and RS28A are? I'd like to use some female disconnects to make connecting and disconnecting the speakers easier during testing.



Will these work?

[Jed]

Can someone tell me how big the terminals on the RS180 and RS28A are? I'd like to use some female disconnects to make connecting and disconnecting the speakers easier during testing.



Will these work?

Although nice for testing drivers, why not use some good solder for the connections?

[opt-e]

Although nice for testing drivers, why not use some good solder for the connections?

I'll definately be soldering everything up once testing is done. Do you know if those are the right size?

[Bent]

If just for test purposes, a pliers and some calculated "squeezing" would certainly ensure they are the "right" size.

Yellow sleaves typicaly mean good for up to a # 10 AWG, no?

[Dennis H]

I realize that port bends will add resistance--but the question is how much and does it make a huge difference? Are there any applications that I can use to model the effect of a port bend?

A smooth bend like you can buy at a plumbing store will only slow the airflow (change the tuning) a fraction of a percent. Measure the length through the center of the bend and it should be fine. Those sharp bends like PE sells don't look so great. FWIW, musical instruments don't have any problem with bends.

[opt-e]

If just for test purposes, a pliers and some calculated "squeezing" would certainly ensure they are the "right" size.

Yellow sleaves typicaly mean good for up to a # 10 AWG, no?

Yep, these are good to 10 gauge.

A smooth bend like you can buy at a plumbing store will only slow the airflow (change the tuning) a fraction of a percent. Measure the length through the center of the bend and it should be fine. Those sharp bends like PE sells don't look so great. FWIW, musical instruments don't have any problem with bends.

Excellent, the radius of the bend of the elbow I got is about 5 or 6 inches, if was was to guesstimate. :T

[ThomasW]

It's better to use a pair of 45 degree elbows instead of a 90, if the 45s will fit

[opt-e]

It's better to use a pair of 45 degree elbows instead of a 90, if the 45s will fit

Great idea :idea:, i'll look into that.

[WillyD]

Although nice for testing drivers, why not use some good solder for the connections?

Whats wrong with using female disconnects? I am using them for my pair of Modulas and all is well.

[Jed]

Whats wrong with using female disconnects? I am using them for my pair of Modulas and all is well.

Just more parts for the signal to go through-- I like to keep my connections as short and minimal as possible. Audible difference..?.. probably not if there is a good mechanical connection. Over time things may become a little less tight- no worries with solder.

[WillyD]

Just more parts for the signal to go through-- I like to keep my connections as short and minimal as possible. Audible difference..?.. probably not if there is a good mechanical connection. Over time things may become a little less tight- no worries with solder.

Well I guess that is where opinion comes into play.

To me, it isn't a "part" but merely an extension of the wire. After crimping the connection is VERY tight/strong. Also, there is really no possible way that the disconnect itself could become loose...not that I can imagine anyway.


But hey, to each his own.

[opt-e]

So today I got started on the enclosures. I'll be ordering parts this weekend and they should arrive in 2-3 weeks.

The pieces, and my trusty sawboard. No fancy schmancy table saw here.



Top, sides, and back glued and screwed. Top piece will be flush trimmed with the router. There's some crazy optical illusion going here; they look tipsy but they really aren't, I swear!



Braces cut and dry fit.



My ghetto workbench ops: Rainy Vancouver in the background.

[dyazdani]

That first assembly pic is funny, as they say down here - they look kind of "wappy-jawed" :B

Good start on the cabinets, flush trims are great...

[opt-e]

Haha.. They're actually square, I have no idea how it ended up like that in the picture :E

[khellandros66]

Its a trick of the eye, the angle of the camera and how the wood in the background are leaning to the left, camera to the right slightly.

LOL I was like WTF too... Like man this guy has coke bottle glasses or something :blink:

~Bob

[Brian Bunge]

Wappy-jawed? I'll have to remember to add Arkansas to my list of states that Georgians are allowed to make fun of. I might actually have to put that #2 after Alabama and move Mississippi to 4th!

[opt-e]

Little more progress since my first update...

• Glued in the bottom and one of the shelf braces.
• Flush trimmed up everything nice and square.
• Cut up my PVC pipe for the port. The PVC elbow actually fits quite snug so I'll just leave the port unglued for now so I can play around with different lengths.
• Assembled a removable back plate which will allow me to access the inside to adjust the port/crossover/stuffing.

That's all for now... waiting for my drivers before I cut any driver holes. Can't wait!

BTW, I ran across this guy on the DIY Mobile Audio forum who has access to PE stuff at cost and is selling parts at quite a big discount off the list price! I didn't find this thread until after I ordered my Natalie P parts :M, but I'm going to go ahead and pick up a couple RSS315HF's and some other goodies while I can. : :T

[WillyD]

Looks good so far, dude!

[opt-e]

So after three weeks of waiting, my parts have finally arrived from PE.

But of course, there is a problem! PE shipped me a resistor marked 4K7 ohms 5W (that measures as 20 ohms?!) instead of the 0.47 ohm 10W I should have got. :E How critical is R3 and can I test without this resistor for now? I don't think I can wait another 3 weeks for the proper part to ship! :roll:

[dyazdani]

Do you have a Radio Shack or somewhere you could pick up a new resistor? You could use one temporarily until you can get a suitable, matching, replacement from PE.

[opt-e]

Do you have a Radio Shack or somewhere you could pick up a new resistor? You could use one temporarily until you can get a suitable, matching, replacement from PE.

I'll look into that...

On a side note I'm really impressed with PE's handling of this mistake. I e-mailed them this morning and they responded an hour or two later saying that they'd ship the correct parts out today. I don't even have to send back the the "wrong" ones. Granted, it's only 78 cents worth of parts, but they could have easily made it difficult for me.

[plincoln]

I'll look into that...

On a side note I'm really impressed with PE's handling of this mistake. I e-mailed them this morning and they responded an hour or two later saying that they'd ship the correct parts out today. I don't even have to send back the the "wrong" ones. Granted, it's only 78 cents worth of parts, but they could have easily made it difficult for me.

Agreed, PE has always been top notch for me as well.

[opt-e]

Got some more stuff done over the past few weeks. Time to build has been limited as I've been doing the PADI Open Water Diver certification and this has consumed all my time over the weekends.

Binding posts! Man these things are friggen huge.



Crossover. Are my inductors okay the way I've placed them?



Baffles with driver holes. This turned out almost perfect with my DIY circle jig, considering my lack of experience with a router and woodworking in general. Only problem I really had was locking the depth on the driver recesses. It's a bit uneven in places. Nothing major though, and those mistakes won't be seen once the drivers are in place.



View from inside.



Couldn't wait to take a listen, so I put the drivers in and hooked everything up to my LM4780 (paralleled) Gainclone and fired it up. All I have to say is, WOW these speakers are awesome. ;x( Now I want to build the TMWW's 8O



Priming... Taking these speakers apart to finish is painful

[Jordan]

Whoa good work!

Did you plugged them in?

How is the sound?

Jordan

[WillyD]

Whoa good work!

Did you plugged them in?

How is the sound?

Jordan

From his post:

"Couldn't wait to take a listen, so I put the drivers in and hooked everything up to my LM4780 (paralleled) Gainclone and fired it up. All I have to say is, WOW these speakers are awesome."

And great job so far, OP.

[Exocer]

Nice job Opt-E. I too am working on the Natalie P's and can't wait to get my enclosures started.

[Jordan]

From his post:

"Couldn't wait to take a listen, so I put the drivers in and hooked everything up to my LM4780 (paralleled) Gainclone and fired it up. All I have to say is, WOW these speakers are awesome."

And great job so far, OP.

Lol good point. I wasn't clear in my first post! I meant after the break up and all.

Jordan

[yousuredo2]

For dual 7's in the larger enclosure with this Sd and Xmax, a flared port is advisable. The preferable configuration would be a straight bottom firing 3" flared port, with 1.5" risers front and rear, and the cabinet supported on adjustable points. The enclosure volume could be upped to as much as 50-58 liters for greater low end extension if you can work with the larger cabinet. But this is by no means mandatory... merely "suggested". Try those sizes in Unibox and see what you think, and check the plots on port velocity and Xmax. I think 120 watts may be a little over the top in the low end, though as an overall power rating for music it's a good choice.

Otherwise, you plans are most satisfactory.

I am going to build these large...
-what size enclosure would you recomend for greater Low end extention ?
-Is deeper/taller prefered ?(I prefer the Look of deep, narrow, and moderatly tall)
-has anyone played with those sizes in UNIBOX, and determind optimal size yet...(some dimisions would be great to get me started building the cabs) ?
-will my sony reciever be enough at a factory rated 100w x5 channel...
-what is the OHM Load of these...
-What is Optimal port size (Lenght) ?

[ThomasW]

-what size enclosure would you recomend for greater Low end extention ?
-Is deeper/taller prefered ?(I prefer the Look of deep, narrow, and moderatly tall)
-has anyone played with those sizes in UNIBOX, and determind optimal size yet...(some dimisions would be great to get me started building the cabs) ?
-will my sony reciever be enough at a factory rated 100w x5 channel...
-what is the OHM Load of these...
-What is Optimal port size (Lenght) ?

You need to be realistic, there are a pair of 7" drivers in this cabinet. You don't want lower extension than the design posted in this thread or you'll kill the woofers with any attempt to play high SPL's. Just copy the information posted here to build your boxes.

Don't know what loads you Sony is rated for.....
The speakers are a 4 ohm load.

[opt-e]

I am going to build these large...
-what size enclosure would you recomend for greater Low end extention ?
-Is deeper/taller prefered ?(I prefer the Look of deep, narrow, and moderatly tall)

My design is slightly less than optimal in terms of bass response. You can extend the cabinet up and back and aim for about 65L, tuning for 32 hz. For a 3" port, it should be about 6.4" long. That'll give you an F3 of 32 hz.

[opt-e]

Finally got my cabinets painted...

[yousuredo2]

Nice....
what did you end up using...

are these the largest anyone has built of the NatP's

[opt-e]

It's 3 coats of white alkyd primer and a couple coats of black pearl-finish acrylic latex applied with a roller.

Mine are probably on the smaller side of what other people have built.

[WillyD]

Great job Anthony! I love the sleek, simple, black look. 8)

Evil Twin should be proud. :twisted:

And if you don't mind me asking, what will your final total cost be for everything (including materials to finish the cabinets).

[opt-e]

Great job Anthony! I love the sleek, simple, black look. 8)

Evil Twin should be proud. :twisted:

And if you don't mind me asking, what will your final total cost be for everything (including materials to finish the cabinets).

Thanks, appreciate the compliments on my first set of DIY speakers!! :T I'm quite happy with the way they've turned out, but I'm a bit jealous of all the veneered projects out there. Chuck's TMWW's are lookin smokin!

Final cost all said and done is about $600 CAD.

My next project is a couple of ported dual RSS315HF subs to relieve the NatP's of bass duty. Already have all the parts and a Behringer CX2310 crossover.

[WillyD]

Ill agree that some of those veneered cabinets out there are amazing. I have doubts about whether or not I could ever build a pair like that though.

I am also considering a pair of subs to relieve the Modula MTs of bass duty. I am thinking about two sealed RSS390s though.

[opt-e]

The build completed

[soho54]

Looks great. I like the minimalist approach. Nice finish.

[opt-e]

Thanks Jacob! Originally I thought the silver mounting screws would look cool but I'm finding them a bit distracting. Debating on switching over to some nice black chrome. What do you think?

[soho54]

Go to the craft section of W-M and get the smallest bottle of acrylic black pant, and a stenciling brush (1/4' semi-hard bristles, in a round pattern the same size as the screw head). Just paint the screws you have with that, using a stabbing motion. It will dry the same color as the RS line black frames. If you don't like it after it dries you can peel it off the bare metal. I always keep some around to touch things up. It will also get rid of the shine on the factory RS tweeter screws as well.

EDIT: The screws are not visible on my speakers from 3 feet. They kind of fad away into the driver's frame.