My Natalie P Journey Begins

[JonMarsh]

Ha!

I will not say thing about the last time someone commented on the hemostats in my tool box!

But mine have a slightly different color on the tips from projects in the far, far past.


These days, I even keep a set of these on the stereo rack for cleaning the stylus on my turntable.

I own a good set of those, but unfortunately, mine are in the work lab at the moment, and my stereo microscope is in my storage unit- had to get by with naked Mk I eyeball. Solution? Squint a lot...

[Hdale85]

Damn...definitely going to have to take a trip to Pittsburgh soon! So many new speakers to listen to!

[wkhanna]

Damn...definitely going to have to take a trip to Pittsburgh soon! So many new speakers to listen to!

Yeah, you really should come by some time!

[JonMarsh]

NatalieP Deluxe for Bill....

OK, making some progress this Saturday, my comp day yesterday got blown off by my boss, but today is wife his probably keeping him busy and at bay... :W


So, what we've got here is an updated schematic proposal for Bill, considering his plan to use the nice and spendy Scanspeak tweeter instead, which is about 4 dB more efficient. And some nice shiny new expensive caps in the crossover, too. Not being one to leave well enough alone, I also have dreamed up a more deluxe version, using a zobel network for the tweeter, which makes things a little more happy in the tweeter roll off. Sort of the OCD approach to a NatalieP, as if one really wanted an Ardent, but was settling because that dip Jonmarsh can't ever seem to finish the Ardent design, and besides, your wife wouldn't approve that much money for crossover parts!

So, first the "standard" upgrade, without the zobel network added:







Quite respectable performance for a budget setup (a few more things tweaked slightly in component values), but no way to fix that unsightly bump in the response of the tweeter that arises from it's Fs impedance peak around 500 Hz.


Next, the slightly higher priced spread:





Mmm,mmm, good!




And just for good measure, the usual sanity check with a reverse connection of the tweeter:



Nothing to complain about there...


well, you could probably build this just on my LspCAD sims and things SHOULD work out just fine, but if you're not in an all fired hurry, I should be able to get parts on hand in early October to build a test channel, (excepting the SS tweeter, which will be a slightly less sensitive version) and build and test this out by Halloween. Right now my discretionary budget for September is tied up in a couple of parts orders for the Isiris midrange re-build, and in a ludicrous amount of new gear to support the music server- as they say, I'm all tapped out! Can't even afford a new guitar this month, not one!!! :roll:

[Rbrockman]

Feeling very fortunate to have just found this discussion! I've been looking for a new speaker build for a 2-channel music only system. These may just be the ticket. My first ever DIY build was the Modula MT many years ago, and am still using these as rear channels. After plunging into home theater for the last few years, I'd like get back into a good music only setup.

This week I've been looking at many DIY builds, all of them requiring a long cabinet build process which I'd like to avoid - and then along comes this build thread - which if I'm following correctly could be completed with the PE 1.0ft cabinets! Please correct me if this is not the case.

I do have a question though. Your build is using a vastly upgraded tweeter over the original NatP. I'm wondering if you ever considered different improved woofers? Perhaps something in between the RS180 and the SS Relevators - maybe something like the Seas Prestige U18RNX/P? Just interested in your thoughts on the woofer selection - I realize you already have the investment in the RS180's.

[wkhanna]

Yes, these are perfect for the PE cabinets.

As I understand, the performance of the RS180 is far above its price point.
But even more importantly, its characteristics fit Jon's design goals incredibly well.
Sometimes you just do not need to spend more to get more.

If you are looking a V good & relatively economical 2-way specifically for music, I can not recommend a better design.
I have been happily using my standard NatP's in my music system for over six years.
During that time, I have made upgrades to every other component & have always been able to extract all of the enhanced performance.
I have heard a lot speakers since I built these & in all honestly, I have yet to come across any retail product that is as balanced, detailed or involving for anything under $4k.

[Evil Twin]

Yes, this can be built with just the PE 1 cu ft MTM cabinet- for more extended low frequency response, a larger DIY floor standing tower with the same width is a path proven by many.

While I am not Bill, and cannot speak to his preferences, as the original designer, I can speak to the issues surrounding component selection for the NatalieP.

• Drivers were selected for neutality within the planned operating range, balanced against cost. Distortion was given equal consideration with response linearity, both non-linear distoriton and linear distortion (resonance within the passband, such as is often revealed with impedance measurments, where mechanical reactances show up as a bump in the impedance curve
• The over riding preference was to avoid sins of commission; let the program speak for itself, to the degree possible within the design budget
• The crossover is an unorthodox design specifically optimized by inherent design for the front to back displacmeent of tweeter and midwoofer mounted on the same baffle; hences, it's derivation from a Linikwitz Riley style 3rd order, which does not work suitably with conincident drivers with acoustic origins in the same plane, and is therefore not studied or understood by most.
• The RS180 has exceptionally low non-linear distortion as almost any 7" woofer goes (even the Scanspeak Illuminator series has little advantage, or the Revelators), and is free of linear resonances in the critical midrange up through 3 kHz.

I do not in fact believe that the Seas you mention would be an "upgrade"-




The woven polypropylene damps the high frequency resonance, outside the desired passband, making crossover development easier for the unskilled. But I discarded using polypropylene cones in the 90's after detailed investigations highlighted resonances and non-pistonic cone behavior which contribute to audible coloration in the midband- evidence of this is seen in the H1571's impedance plot.

For this type of system, the question arises, for a two way, what is a true performance upgrade within the physical format of dual 7" woofers that have to work cleanly up to about 3 kHz to manage an 1800 Hz 3rd order crossover? Design changes which better optimize the low end usually compromise efficiency and upper range behavior. Even the very expensive Illuminator mid woofers do not make a clear value proposition case, if a two way is chosen.

Generally, the next step of optimization beyond tweeter and crossover components would be adding an external subwoofer- this will essentially convert this to a three way system with a low crossover point to the woofer. IF this path is planned, then sticking with the 1 cu ft MTM enclosure in one of it's variants makes the most sense, unless you desire esthetic embellishments with more exotic wood finishes than PE offers.

[wkhanna]

So as not to disrupt or cause conflicting humors of space/time continuum within the force, a new thread entitled My Natalie P Journey Continues has been created & implemented as per instructions due to intercepted communications from Rebel Command.

[Evil Twin]

So as not to disrupt or cause conflicting humors of space/time continuum within the force, a new thread entitled My Natalie P Journey Continues has been created & implemented as per instructions due to intercepted communications from Rebel Command.

A very wise move- there is enough confusion here due to the ongoing influence of the Rebellion here, that we do not want to unduly distract the new DIY apprentices.