Natalie P questions

[ba123]

I am about to order all the parts for the NatP's from parts express and had a few last questions.

As far as my order-

1- Would the 3/4" 3-layer sonic barrier be OK, or should I use 1 1/4"? ($90 vs $120 @ 6 sheets)

2- Would this be good for internal crossover and external speaker wiring?

And as far as the build-

3- For a small tower are soundbites internal dimensions of 7.5”x9.5”x48” recommended?

4- On the crossover pic (below) is the cross just to the right of the .44 iinductor a intersection of the wires or are they separate?

And lastly-

5- Will my old nad 1155 amp w/ 55w X 2 be enough to drive these, or should I like for a new amp?


Thats it. Thank you all for all the work in these projects. I am really looking forward to trying my first diy speaker project. :T

[JonMarsh]

1). Should be alright, but I haven't tried it. I use the thicker stuff, from WhisperMat. If it's a budget breaker, go for what you can afford.

2) Should be OK- I'm not fond of PVC insulation myself, but that's a good price for wire. I built mine with Cardas Crosslink speaker cable, which is about $3.50 a foot if I remember correctly- check out the Modula MTM thread to see.

3) Does it add up to 50 liters or so? (I'm packing for a business trip right now, so this is the Y part of DIY! I like a little deeper for the midrange backwave. The ideal thing would be to follow the PE enclosure size, but extend the height; if you want it taller than would work out to 50 liters, just block it, unless you're putting the port in the bottom.

4) LspCAD doesn't put junctions where wires connect- that IS a connection. All four.

5) It should be fine to get you started, as long as it's happy with 4 ohm loads- most NAD amps are, that was part of their deal, able to drive low impedance loads.

[Jim Holtz]

I am about to order all the parts for the NatP's from parts express and had a few last questions.

As far as my order-

1- Would the 3/4" 3-layer sonic barrier be OK, or should I use 1 1/4"? ($90 vs $120 @ 6 sheets)

2- Would this be good for internal crossover and external speaker wiring?

And as far as the build-

3- For a small tower are soundbites internal dimensions of 7.5”x9.5”x48” recommended?

4- On the crossover pic (below) is the cross just to the right of the .44 iinductor a intersection of the wires or are they separate?

And lastly-

5- Will my old nad 1155 amp w/ 55w X 2 be enough to drive these, or should I like for a new amp?


Thats it. Thank you all for all the work in these projects. I am really looking forward to trying my first diy speaker project. :T

Here's the wire I use and recommend: http://www.apexjr.com/wire.html
I like the 14 gauge sliver plated teflon coated variety for internal wiring. Top quality and easy to solder. I woul;dn't recommend it for external wiring. Many other choices.

For foam, the somic barrier is fine but not at that price. If you're just building the one project, you're getting way too much. You can also roll your own with the asphalt sheeting and 1 1/2" eggcrate foam from PE for much less.

Here's another excellent option for foam:

http://www.foambymail.com/Wedge.html

And another:

http://www.silentsource.com/index.html

Dimensions of 9"W x 11"D x 49"H will get you 50 liters with a 1 1/4" thick front baffle.


HTH

Jim

[silvercans]

http://www.foambymail.com/Wedge.html

Would you go with the 2" or 1" thick foam?

[ba123]

Wow, thanks for all your reply's.

The $120 cost of the sonic barrier is 6- (18" X 24") sheets @ $19.90. That is enough to do 3 sides of 2 48" towers. I checked the wedge foam and vinyl and for the same amount it is almost as much. Am I wrong about putting it on all sides?

[ba123]

Also, I think I will use the cardas cable found here. In the thread with the picture below it mentions these leads go to the 2 dayton drivers, but for for external use would I wire the pair ends together into traditional 2-wire cables, or is there better wire for that?

Thanks again for your help.

[BobEllis]

www.markertek.com also has egg crate foam real cheap. IIRC, $27 for 54"x54"x2" works fine.

As far as I am concened, wire is wire as long as it is big enough. Why sweat a few feet of speaker cable when it goes into a nice looking spool with 80' of generic magnet wire? I like the Dayton 12 gauge wire everywhere except the tweeter circuits where it becomes too hard to solder and I use 16 gauge zip cord.

The Cardas stuff sure is pretty, though.

Yeah, I am a tightwad

[Jim Holtz]

Wow, thanks for all your reply's.

The $120 cost of the sonic barrier is 6- (18" X 24") sheets @ $19.90. That is enough to do 3 sides of 2 48" towers. I checked the wedge foam and vinyl and for the same amount it is almost as much. Am I wrong about putting it on all sides?

I'm a little lost how you're going to use 18 sq. ft. of sonic barrier lining the walls of the two cabinets. You are just lining the three interior walls, correct?

Jim

[Jim Holtz]

Would you go with the 2" or 1" thick foam?

2" foam. I just bought 48 sq. ft. of it in the larger buy they list. It is very nice foam and has a great NRC rating. This is a whole lot cheaper than the other alternatives other than the Walmart eggcrate stuff some folks use.

Jim

[ba123]

The interior has 2 sides @ 7.5" and a back @ 9.5" so that uses the 24" width and the sides are 48" high so 3 @ 18" = 48". So that should be 3 @ 18"X24" per box. Am I wrong?

[ba123]

Thanks for all your help. I went ahead and placed my order for all the NatP parts with parts express and I ordered the 1 1/4" sonic barrier foam.

Thanks again for your help.

[jclin4]

Finished Madisound Cabinet

I also want to build the Natalie P as a tower. I'm thinking of using the new finished cabinets from Madisound. The baffle width is the same as the PE MTM cabinets: 9 inches.

There's a movable shelf that allows the upper portion to match the 29.4 liter internal volume of the PE Cab...or I could use the maximum volume of 38.2 liters.

Would the port dimensions need to be adjusted, if I went with the larger volume?

I used Precision 2" ports from PE; the center tube will need to be cut to 3-1/4" to 3-1/2"

Also, since the baffle is the same width, I assume no XO changes would be required. Is this right?

[ThomasW]

Collo's little program is very handy for those wanting to experiment with different box sizes and port tunings

http://www.users.bigpond.com/bcolliso/freesoft.htm

[ba123]

Sorry, but I am off to the lumberyard tomorrow and have a couple more questions about how much material and what router bits to buy.

I am going to use 3/4" MDF and a veneer finish for the cabinets, but....

1- What is the recommended thickness of the front baffle (3/4 or 1 1/2)?

2- Is it recommended to flush mount the drivers?

3- If I round over the cabinet corners, to keep my baffle width do I widen the cabinet to the edge of the roundover, or does it stay the same?

4- And lastly, is there a recommended way to build grills, or would it sound better without them?

Thanks again.

[Dotay]

You can also roll your own with the asphalt sheeting and 1 1/2" eggcrate foam from PE for much less.

Would you care to elaborate on this or provide links that describe this process? Please and thanks.

[Jim Holtz]

Would you care to elaborate on this or provide links that describe this process? Please and thanks.

It's relately easy to come up with a similar product to PE's Sound Barrier. Simply combine this asphalt sheeting (http://www.partsexpress.com/pe/showd...number=268-020) and 1 1/2" eggcrate foam (http://www.partsexpress.com/pe/pshow...number=260-516) using spray on 3M #90 contact cement. The asphalt sheeting has a self adhesive backing and sticks tight. It's also available in smaller sizes than the one I listed.

Another alternative for foam is Foam By Mail (http://www.foambymail.com/Products.html) I just ordered 48 sq. ft. of the 2" wedge which has a NRC rating of 81.

Actually, if the box is well braced, you won't see much if any benifit from the asphalt sheeting. The wedge foam would be a good solution just by its self. Attach with 3M contact cement directly to the walls of the cabinet.

I've used this method many times with success. I can't see or hear a diffeence between this and Blackhole 5, Whispermat or Sonic Barrier. YMMV

Jim

[Dotay]

Thanks for the response Jim, makes sense now. Would using something like the peel and stick tiles as EdL suggests this post work on the same principle? Would one work noticeably better than the other or it kind of splitting hairs at that point?

[ba123]

Thank you all for your help. I just got my NatP's finished and they're up and running and sound fantastic. I am really impressed with the bottom end of these speakers. I haven't rounded my edges or veneered them yet - giving them a week or two to make sure everything stays put - but when I do I'll post a couple pictures. Thanks again for the collective design and all your support.

[madclown99]

http://www.foambymail.com/Wedge.html

I'm going to buy 72sq ft of 2" wedge foam from this place, they also sell 17oz cans of spray adhesive. Is this the best way to attach the foam and how many sq ft will 1 can cover?

[Evil Twin]

Thank you all for your help. I just got my NatP's finished and they're up and running and sound fantastic. I am really impressed with the bottom end of these speakers. I haven't rounded my edges or veneered them yet - giving them a week or two to make sure everything stays put - but when I do I'll post a couple pictures. Thanks again for the collective design and all your support.

Yes, I thought I felt a new current in the Force... Congratulations on completing your initial apprenticeship. These speakers are multiplying like clone troopers...

[Brian Bunge]

The first speaker kits I built from ACI years ago came with 2" acoustic foam and they suggested using silicone to attach the foam to the cabinet walls. Worked like a charm but every time I leaned over the cabinet to stick another piece in the cabinets the fumes damn near killed me.

[Jim Holtz]

I'm going to buy 72sq ft of 2" wedge foam from this place, they also sell 17oz cans of spray adhesive. Is this the best way to attach the foam and how many sq ft will 1 can cover?

Sorry, I really can't answer your questions. I use 3M #90 spray contact cement. I'm sure #77 would work just fine also. I'm not familiar with Foam by Mail's contact cement but I suspect it would be just fine. The price is right if shipping doesn't get you.

The foam is easy to work with and should do a great job based on it's NRC rating.

Jim

[opt-e]

Thank you all for your help. I just got my NatP's finished and they're up and running and sound fantastic. I am really impressed with the bottom end of these speakers. I haven't rounded my edges or veneered them yet - giving them a week or two to make sure everything stays put - but when I do I'll post a couple pictures. Thanks again for the collective design and all your support.

Where are the pictures?

I just started construction on my pair of NatP's last weekend. Can't wait to finish 'em but I'm already thinking about what to build next 8O This DIY stuff sure is addictive... and expensive ops: :E

[Jim Holtz]

Did you say next project?

Where are the pictures?

I just started construction on my pair of NatP's last weekend. Can't wait to finish 'em but I'm already thinking about what to build next 8O This DIY stuff sure is addictive... and expensive ops: :E

If you like the Natalie P. then this is a natural. Extremely nice!

It's Dennis Murphy's RS 3-way design with dual RS225's, RS150 and a Seas 27TBFC/G tweeter. Ultra smooth and detailed. :T

Jim

[Jonasz]

Jim: Very very nice speakers! :T

Maybe these are what I should build for my sister? I was thinking about the Natalie P but these looks like they can move some serious amounts of air! :B

Jim can you give us a subjective sound comparison between these two candidates? Also, what is the approximate difference in cost regarding drivers and crossoverparts between the two?

Jonas

[Jim Holtz]

Jim: Very very nice speakers! :T

Maybe these are what I should build for my sister? I was thinking about the Natalie P but these looks like they can move some serious amounts of air! :B

Jim can you give us a subjective sound comparison between these two candidates? Also, what is the approximate difference in cost regarding drivers and crossoverparts between the two?

Jonas

Jonas,

Thank you for the kind remarks. I appreciate it!

The Natalie P and the RS 3-ways are both fine speakers and I suspect your sister would be very pleased with either one. There are many similarities as you might imagine since they are both using RS drivers.

That said, the RS 3-ways have some distinct advantages, IMHO. The dual RS225’s will move substantial amounts of air. I’m a sealed bass fan which is the way I built these. F3 of 49 Hz. is low enough that room gain plus the much slower roll off of sealed bass provides substantial bass down into the 30’s. Ultra clean and powerful I might add.

I also prefer the H1212 to the RS28. They sound very similar and full bodied but the H1212 is more extended sounding to my ears. The RS28 just sounds a bit dead on top, IMHO.

Mids are very smooth and detailed on both the Natalie P. and the RS 3-way so there are less differences. Dennis is a proponent of and used 2nd order slopes in the RS 3-way so it has a little different presentation than the Natalie P. There might be a slight edge in imaging with the RS 3-way but the differences are more a matter of taste than anything.

If you’ve never heard one of Dennis’s designs you’re in for a treat. He meticulously voices his designs and listens to extremely demanding music to be sure that they sound just right before ever signing off on the design. They are never harsh and always very smooth and accurate sounding to my ears. They do everything extremely well and some things so well that you wonder how much more sound quality mega buck speakers can offer. They’re just really very, very nice. :T

There is a cost difference, however. The Natalie P’s will run about $310 USD for drivers and crossover parts. The RS 3-ways will run about $460 USD for drivers and crossover parts. Those prices are based on Dayton caps, Eagle resistors and Madisound or Jantzan inductors. Whether the sound quality differences are worth it is a subjective decision.

HTH

Jim

[opt-e]

If you like the Natalie P. then this is a natural. Extremely nice!

It's Dennis Murphy's RS 3-way design with dual RS225's, RS150 and a Seas 27TBFC/G tweeter. Ultra smooth and detailed. :T

Those shore are purrty However, I was thinking more along the lines of a standmount monitor to replace the B&W 600S3's in my bedroom system. Peerless Exclusive 7" and a 27TDFC perhaps.

[Jim Holtz]

Those shore are purrty However, I was thinking more along the lines of a standmount monitor to replace the B&W 600S3's in my bedroom system. Peerless Exclusive 7" and a 27TDFC perhaps.

Thanks for the kind remarks.

How about John K's (not Krutke) new NaO Mini? It's a di-pole but I don't think the crossover would change if it was put in a box. John posted on MAD that he was going to give it away as a free design.

Jim

[opt-e]

How about John K's (not Krutke) new NaO Mini? It's a di-pole but I don't think the crossover would change if it was put in a box. John posted on MAD that he was going to give it away as a free design.

I've been wanting to try an open baffle/dipole design for quite some time now but I have neither the space nor the money to build such a system. Perhaps sometime in the not so near future I'll do an all out Arvo :T

[Jim Holtz]

I've been wanting to try an open baffle/dipole design for quite some time now but I have neither the space nor the money to build such a system. Perhaps sometime in the not so near future I'll do an all out Arvo :T

Actually, the NaO Mini is a MTM with 7" Exclusive woofers and a 27TDFC tweeter. What I meant was, you could use John K's crossover for a conventional speaker using those drivers which I think was what you asked for.

Jim

[opt-e]

Oh okay, I misinterpreted that Thanks.