Announcement

**technodanvan** · 20 March 2023, 14:59 Monday

I will build this.

**Efalegalo** · 20 March 2023, 15:39 Monday

I too will build this!!!

**theSven** · 20 March 2023, 16:06 Monday

This sounds like it would make an excellent surround for the 7.x I have been dreaming to create. Does Evil Twin have any cabinet designs to share for this design?

**Evil Twin** · 21 March 2023, 09:23 Tuesday

There is a 3D CAD drawing started for the sealed version of this concept- it should be ready to show soon. In its present form, it is derived from the SMJ-40 concept project, basically an extended version of the top module cabinet. I have taken over THAT effort also, and an update will be coming there as soon as some local communication issues are ironed out, with regards to an "assistant" interfacing with the local telecommunication infrastructure.

Expect a 10-1/2" cabinet width, approximately 24" tall, and 12-14" deep. Width is "fixed" at this point, the other two parameters will be adjusted to achieve a suitable height and necessary cabinet volume.

**Evil Twin** · 21 March 2023, 10:00 Tuesday

Originally posted by svenarajala View Post

This sounds like it would make an excellent surround for the 7.x I have been dreaming to create. Does Evil Twin have any cabinet designs to share for this design?

The timing and perspicacity of your inquiry leads me to speculate that perhaps you are in alliance with Rebel spies active near this facility...

It is most curious that the server reports that I was not "authorized" to make this comment in a "Comment"... is there a prohibition against Siths?

**Evil Twin** · 21 March 2023, 10:02 Tuesday

While showing that I was logged in, the system nonetheless required a password again to enter the post above.

**Evil Twin** · 21 March 2023, 15:46 Tuesday

I am aware of that requirement. However, I had logged in "fresh" this morning.

**Evil Twin** · 21 March 2023, 21:58 Tuesday

Two examples of enclosure concepts being considered...

For the sealed 28L net application, and for the 48L net Passive Radiator approach.

Sealed 28L net...

The high volume enclosures could be fabricated as a tower, but my experience shows that often creates issues with column resonance. So, a different approach is used here, requiring a stand suitable to the listening circumstances.

**DonGalgr** · 22 March 2023, 11:53 Wednesday

This looks awesome, I will build these. I have been looking for a good home for my pair of Peerless DA25TX's. Is the choice of the Dayton RSS210HF fixed enough to put these on order? I can play with them as the design finalizes.

**Evil Twin** · 22 March 2023, 13:06 Wednesday

The choice of the RSS210HF-4 is VERY fixed- having tested many 7" and 8" woofers, it's combination of superior cone behavior of a wide frequency range, a linear motor with three faraday rings, and moderate Xmax and sensitivity have earmarked it for several designs- there are currently 8 on hand in my lab storage, with more coming in the end of this week.

Note, for one application 4 are being employed in series parallel, and at 90 dB output the distortion signature for HD2 and HD3 looks like this:

I consider this to be "most satisfactory"... Note that the distortion spikes are outside the operating range and can be greatly reduced or eliminated by series notch filters in the last stage of the LF crossover.

The RS210HF-4 is another driver that straddles the "divide" between a subwoofer and woofer, with T/S parameters enabling extended bass, but having a motor and cone design which is clean to a relatively high frequency with monotonically decreasing distortion, unlike some other newer products (like the E180HE-44) which did not live up to expectations when tested in our lab... Of course, there is no avoiding Hoffman's Iron law, so the price to be paid is lower sensitivity for extended bass performance in moderate size enclosures- not too unlike the 6.5" PuriFi drivers.

Using data measured in other cabinets or QNF, a POC crossover has been developed to give a clearer picture by using baffle modeling with the QNF data; a design will not be fully developed until actual measurements can be made on a sample cabinet.

This incorporates Notch filters for both woofer and tweeter breakup modes, which as demonstrated with the Calliope system, and the original Natalie P, greatly reduce or eliminate resonance amplification of distortion products.

All wood materials are on hand for the initial prototype build for the sealed cabinet version. Once a test cabinet has been constructed, measurements will be collected and the crossover development will proceed in earnest.

**Evil Twin** · 23 March 2023, 09:34 Thursday

Some topological updates to the crossover were explored to lay the ground for working with measured data in the test cabinet when available...

Normal connection SPL

Reverse Null connection SPL

**DonGalgr** · 23 March 2023, 19:38 Thursday

The RSS210HF is on sale at the moment at Parts Express for $114.98.

**technodanvan** · 23 March 2023, 20:22 Thursday

Originally posted by DonGalgr View Post

The RSS210HF is on sale at the moment at Parts Express for $114.98.

Why do you hate me?

**Evil Twin** · 24 March 2023, 09:56 Friday

I believe you might say Don is just exhibiting the more playful part of the Dark Side of the Force...

**technodanvan** · 24 March 2023, 12:08 Friday

As an aside, I'm going to go out on a limb and suggest anyone who doesn't paint these black will have a dark visitor.

**Evil Twin** · 24 March 2023, 21:36 Friday

Originally posted by technodanvan View Post

As an aside, I'm going to go out on a limb and suggest anyone who doesn't paint these black will have a dark visitor.

This might be a reasonable inference in it's basic expression... but "paint"?

If one aspires to that ultimate expression of confidence and power, mere "paint" is not a satisfactory effort...

Something requiring more research and focus will be expected....

this is an "adequate" example...

Otherwise, following that example, and the planned construction for this set, using premium materials such as bamboo composite and pin block maple ply, a skilled application of wipe on polyurethane would be considered "acceptable". Note the use of the word "skilled"... there are standards to be upheld.

**Evil Twin** · 28 March 2023, 16:13 Tuesday

Some questions have arisen in private communications regarding the enclosure alignments, particularly the sealed alignment...

In one popular tool, the inquirer noted that it calculated a Qtc of 0.9 for the sealed alignment, and was concerned that this might have audibly degraded response, as regards step transient response, compared with a classic Butterworth 2nd order with a Qtc of 0.707, I.E., -3dB at Fs.

Obviously, with a system F3 of 41 Hz, and a system Fb of 46 Hz, something is going on....

Let us explore this question a bit.

First, let me remind curious minds that only a Q of 0.5 or lower is critically damped. For this alignment, the response is -6dB. This seems an impractical or undesirable target in some regards, but one fairly well known manufacturer from Boulder Colorado employed this, given the consideration that the speakers were to be located in a Cardas arrangement at sufficient distance from boundaries such that the boundary lift of 6dB occurred at the system Fb.

The tool used for preliminary enclosure design in the case of the Natalie P Ultra is Unibox, created by Cristian Ougaard 23 years ago, to run under Excel, which thankfully it still does, macros and all.

In the configuration optimization for the sealed enclosure case, there are four options for enclosure damping, and the one used is "Heavy Fill". With "No Fill", the calculated Qtc is 0.925; with "Minimal Fill", 0.921, with walls covered (it does not say what they are covered with...) 0.891, and with "Heavy Fill" 0.801. Of course, for alignments like vented and passive radiator, the typical usage is wall covered, though I have created systems in the past which benefitted from heavy fill- it all depends on the complete assessment of the alignment.

Note that both the vented and PR alignment proposed here for the Natalie P Ultra are not sharply tuned as regards the Helmholtz resonance and behavior more like a Bessel filter in the roll off and step characteristic instead of a Butterworth or Chebyshev.

Of course, regarding how "tight" the bass is, if one is truly referring to transient step response, as opposed to merely avoiding a bloat or hump in the bandpass due to poor system response or placement, calculating the step response can be reasonably illuminating...

Natalie P Ultra Sealed 28L net

Natalie P Ultra Vented, 40L

Natalie P Ultra 1 RSS265PR 48L net

Note that this is a soft corner relatively well damped Passive Radiator design. See the posted calculated response curve earlier in the topic.

**Efalegalo** · 29 March 2023, 17:21 Wednesday

ET - Thanks for the post above.

One question: is offsetting the tweeter an option?

**Evil Twin** · 29 March 2023, 22:14 Wednesday

That was not planned for the development of this system- there are potential reasons to consider that if a speaker is not going to be toed in, but it requires a more thorough examination of the directivity on the enclosure and adjustments to the crossover, as was done for the original Natalie P.

**technodanvan** · 30 March 2023, 18:50 Thursday

I just noticed you don't have the tweeters flush mounted in your models, is that on purpose? My (albeit limited) understanding is that would exacerbate the time differential between tweeter and woofer.

Also, I seem to recall the Calliope using felt around the tweeter. Will that be recommended for this design as well? Or am I mistaken...

**Evil Twin** · 30 March 2023, 19:50 Thursday

The baffle plate for the DA25TX00-08 is fairly thin- and with the use of a felt pad in the tweeter region, rebating is optional. This is another reason that the dual purpose brace/crossover platform acts as a subenclsoure for the tweeter, so that it does not have a rear pressure wave to contend with.

**Steve Manning** · 30 March 2023, 21:49 Thursday

FYI Danny, for both the Calliope and the Ardent D, the tweeters are recessed and no felt in site.

**Evil Twin** · 31 March 2023, 10:18 Friday

Is this the time I should mention my "secret" plan to create and evaluate Wilson style diffraction rings on the tweeters?

**Evil Twin** · 01 April 2023, 11:28 Saturday

This topic is no longer a "Design Study" but is now an active construction and test project.

2D detailed drawings are nearly complete for the 28-30L enclosure concept, and part fabrication is underway. PDF's should be posted shortly.

Components are being collected for the initial POC crossover development, and drivers are ready.

**technodanvan** · 01 April 2023, 16:00 Saturday

Originally posted by Evil Twin View Post

...drivers are ready.

As are mine!

Edit: For those interested in the PR version of these, the PR in question is on sale right now.

https://www.parts-express.com/Dayton...500?quantity=1

**Evil Twin** · 03 April 2023, 09:59 Monday

Now I will share some preliminary drawings which may be "useful" for those considering their own build of the sealed version in the near future...

Note that the front panel design posted here was created with a 1-1/8" width, as is available for single sheet MDF. The Imperial build from DFAL will use 1-1/4" maple ply, due to its superior mechanical properties.

PDF's for download are below of all cabinet parts.

Attached Files

**Efalegalo** · 03 April 2023, 15:44 Monday

Originally posted by technodanvan View Post

As are mine!

Edit: For those interested in the PR version of these, the PR in question is on sale right now.

https://www.parts-express.com/Dayton...500?quantity=1

Tempting - but the smaller/sealed enclosure is equally tempting. Decisions - Decisions!

**Efalegalo** · 03 April 2023, 16:26 Monday

Originally posted by Evil Twin View Post

........and fabrication is underway.

How exciting - looking forward to your results. I'm curious if the performance of the tweeter will be impacted at all by the tall surrounds of the woofers.

A few years ago, I made an MTM using Dayton ND105s and Vifa BC25SC06-04. The performance of the tweeter was severely compromised due to woofers' high surrounds and close proximity (further exasperated by symmetrical tweeter placement).

**technodanvan** · 03 April 2023, 17:53 Monday

I think I'll be going sealed for these, and I might make three (if Parts Express seriously has one Peerless tweeter actually available). I have been wanting to make a standmount loudspeaker with PR, but I believe I am set on a design by the late Jeff Bagby - the Helios. These may make a very nice LCR setup for a game room though.

I did order 8 PRs anyway (to go with the 12 I already have for another project) for my version of the Saint-Saëns loudspeaker.

**theSven** · 03 April 2023, 21:26 Monday

I'm leaning towards sealed too for these and would use them for rear and side surrounds. Bear built some Helios a year or two ago I seem to recall. I also am thinking very seriously about the SMJ-40 as I have wanted a ribbon tweeter build forever and a day. I was fascinated from when I heard a ribbon set a friend had.

**JonMarsh** · 03 April 2023, 22:51 Monday

Originally posted by technodanvan View Post

I think I'll be going sealed for these, and I might make three (if Parts Express seriously has one Peerless tweeter actually available). I have been wanting to make a standmount loudspeaker with PR, but I believe I am set on a design by the late Jeff Bagby - the Helios. These may make a very nice LCR setup for a game room though.

I did order 8 PRs anyway (to go with the 12 I already have for another project) for my version of the Saint-Saëns loudspeaker.

You'll find that you can't buy just that one, because of how Peerless setup a minimum quantity.

I have three more coming with order processing pending on the last three at an Australian distributor- if you want one of these, I can sell it to you at my cost, but that came to about $100 each with shipping. Of course, if you know of a better performing tweeter for $100, please let me know- Steve and I have been looking for a while!

I have about 7 pairs on hand saved for Steve's projects and for ET's Natalie P Ultra LE build. LE stands for Limited Edition- as in the sourcing of the tweeter.

**Efalegalo** · 04 April 2023, 00:01 Tuesday

Originally posted by technodanvan View Post

I did order 8 PRs anyway (to go with the 12 I already have for another project) for my version of the Saint-Saëns loudspeaker.

Y’all are just crazy!!!!

**JonMarsh** · 04 April 2023, 10:15 Tuesday

Hey, Danny's not crazy, he's just taking a proactive measure to manage supply chain issues in the modern world!

I currently have 12 Dayton PRs of various sizes on hand, and 8 of the new SLR26R XM003.

Of course, I have delusions of running an engineering research group for speaker building in my golden years, too... I'm not sure what Danny's reasoning is!

Besides, this way, Steve can't whine at me about supply chain issues considering how I'm doing my part!

Oh, and notice @ 12 AM today that the 3 DA25TX00-8 are shipping from Australia.

G'day, mate!

**technodanvan** · 04 April 2023, 11:02 Tuesday

Originally posted by Efalegalo View Post

Y’all are just crazy!!!!

I resemble that remark!

Originally posted by JonMarsh View Post

Hey, Danny's not crazy, he's just taking a proactive measure to manage supply chain issues in the modern world!

I currently have 12 Dayton PRs of various sizes on hand, and 8 of the new SLR26R XM003.

Of course, I have delusions of running an engineering research group for speaker building in my golden years, too... I'm not sure what Danny's reasoning is!

Supply chain concerns are definitely a part of it. Taking advantage of sales is another, so I'm disproportionately PR-heavy right now. Of course, for every new project I decide to add, the queue gets backed up further and further. I think I know my next build (all parts in hand for at least two years now) but that will push my own loudspeaker design even further. Here in Las Vegas, that might not be a bad thing. I'm much more productive in the cool months, and it would be beneficial to only work on 'small' projects during the summer. Maybe it would be best to tackle my own design(s) in the late autumn...maybe by then Jon will have a spare day or two to help me out with measurements and crossover design!

In any case, I'm sure my backlog of projects and inventory of drivers pales in comparison to Jon's!

Being part of an engineering research group for speaker building sounds like a blast! Alas, I'm a bit short on the technical capability to contribute much more than genuine enthusiasm for the craft.

Edit: I'm going to get that last tweeter Jon, even if I have to call the CEO of Parts Express!

**Steve Manning** · 04 April 2023, 11:31 Tuesday

Hey Danny, call the CEO anyway and tell him to place a frigin order with Peerless so we can buy them for our projects!

**technodanvan** · 04 April 2023, 12:45 Tuesday

I mean, I imagine this design would be fairly popular among the DIY crowd if the parts were all available. Maybe if one were to demonstrate this and the other designs are freely available to the community they'd make an order? This one even uses Dayton parts, so it's a full PE build - they should probably make some premade cabinets for a kit!

Barring that, I wonder what it would take to do a group buy. I could see keeping several pairs in storage for myself, plus building a 7.1+ system out of the Nat P Ultra LE would probably be pretty killer.

**Scareurpasenger** · 05 April 2023, 08:09 Wednesday

Has anyone tried allicdata before? They show stock.

**Scareurpasenger** · 05 April 2023, 08:38 Wednesday

Any chance that a variation with the t34b would be considered? I “accidentally bought some” thinking I could take on the built cost/size of the iris but am really liking this concept.

**Evil Twin** · 05 April 2023, 10:15 Wednesday

Originally posted by Scareurpasenger View Post

Any chance that a variation with the t34b would be considered? I “accidentally bought some” thinking I could take on the built cost/size of the iris but am really liking this concept.

This is quite within the realm of possibility, as another set of T34B are on hand, and getting reliable data for this configuration would be straight forward.

**Scareurpasenger** · 05 April 2023, 14:13 Wednesday

My memory failed me. I have the t34a.

**Evil Twin** · 05 April 2023, 16:51 Wednesday

The differences are relatively simple to account for- a slightly lower breakup mode peak frequency (29kHz instead of 31kHz) and a top end that is softer by about 2dB above 5-6 kHz. Some may even prefer that...

As I have both types on hand, checking the design characteristics will not be challenging in the least...

**technodanvan** · 12 April 2023, 15:55 Wednesday

I have officially received the very last Peerless DA25TX from Parts Express. I haven't heard a thing from that other website yet, curious if anyone else has?

**JonMarsh** · 13 April 2023, 10:04 Thursday

I just received the last three DA25TX from Waggner online in Australia... the total cost per piece from them has been about $100. Well worth it in my opinion...

**theSven** · 14 April 2023, 04:57 Friday

Originally posted by JonMarsh View Post

I just received the last three DA25TX from Waggner online in Australia... the total cost per piece from them has been about $100. Well worth it in my opinion...

The $50.00 tweeter is was $100.00 USD, was that from shipping I imagine? Having two build with these this tweeter I admit I still get a smile on my face when I hear them. It will always bring a memory back of when I went to Steve Manning house in 2019 to hear the TTC build when I made the decision to go DIY for new speakers as my friend wanted his back that were graciously on loan to me for 6 years till he could get a house with space to use them. Steve showed me to the chair, put on some music and it was hook, line, sinker from that point on. When I asked Steve what kind of tweeter that was on the SMJ Calliope he said it was titanium... I said come again??? I guess it was love at first listening session... Yes! I can say for my ears I really love the way this tweeter sounds and the designs JonMarsh has created attest to that.

Announcement

What if the Wavecor Ardent and Natalie P had a "love child"?

What if the Wavecor Ardent and Natalie P had a "love child"?

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