Total agree. The only thing that got me considering the Tectonics is that Dennis Murphy used them in his BMR models. I have a good bit of respect for his design abilities and he uses them between Purifi woofers and Raal tweeters.
Now, I'm leaning toward the PTT4.0M04-NFC. Lots of $$$$ though.
Now, I'm leaning toward the PTT4.0M04-NFC. Lots of $$$$ though.
Peter, what are your thoughts about the Scan-speak 10F? It sure seems to check a lot of boxes for a very reasonable price. But, I've heard a few say they just don't care for the sound of it.
Why not one of the Bliesma M74 versions? Seems perfect for your application, not cheap, but nor are the Purifi. 🙂
Yeah we can argue now everything that has roughly an OD of 4" and was not able to flee fast enough... 😛😀
So what we're taking about here? Let me quote Troels because he wrote a nice summary here:
Applied to our discussion, with the mentioned Purifi, Kartesian, Illuminator, and also Bliesma M74 you get that dynamic headroom for the money due to strong, stable magnetic circuits and especially large voicecoils that can take electrical power. (BTW: that simple tradeoff was driving also my choice for the WO24P: What gives the most linear displacement volume = dynamic headroom for a driver size 8"-10", as small diameter as possible, with a low distortion magnetic circuit?)
The Tectronics, 10F, and a few more we may dig out play nicely linear within their passbands, and may be sufficient for Paul's needs depending on the requirements. (BTW: SB12NRCX2 was my budget recommendation, because it seems to give the most max peak SPL in my rough simulations in comparison to others. And seems to be flawless in the midband. 10F is also flawless, it just has a tiny voicecoil that cannot be pushed so much.)
@Paul: Therefore I think we have to get your needs and the system context more clear.
So what we're taking about here? Let me quote Troels because he wrote a nice summary here:
Applied to our discussion, with the mentioned Purifi, Kartesian, Illuminator, and also Bliesma M74 you get that dynamic headroom for the money due to strong, stable magnetic circuits and especially large voicecoils that can take electrical power. (BTW: that simple tradeoff was driving also my choice for the WO24P: What gives the most linear displacement volume = dynamic headroom for a driver size 8"-10", as small diameter as possible, with a low distortion magnetic circuit?)
The Tectronics, 10F, and a few more we may dig out play nicely linear within their passbands, and may be sufficient for Paul's needs depending on the requirements. (BTW: SB12NRCX2 was my budget recommendation, because it seems to give the most max peak SPL in my rough simulations in comparison to others. And seems to be flawless in the midband. 10F is also flawless, it just has a tiny voicecoil that cannot be pushed so much.)
@Paul: Therefore I think we have to get your needs and the system context more clear.
- Will the setup stay Purifi PTT6.5 + new Mid + Bliesma T25B, or do you plan to add a second 6.5 Purifi woofer or some Subwoofers?
- What amplifiers are you using?
- What music do you listen to? With what usual listening volume? At what distance to the speakers?
- What are your requirements to the "look and feel" of the driver?
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The biggest issue generally speaking with 4 inch mids, would always be maxSPL aka dynamic range.
Crossing them a little higher could help a bit, but it might not work out well with the woofer.
A 5 inch will have a lot more in sense of sensitivity as well as max power, therefor a much higher maxSPL as well as lower distortion.
But the penalty will be an higher directivity, therefor it will sound different.
I personally also wouldn't use them anymore without a waveguided tweeter, since the directivity mismatch.
In this particular system, I don't see many benefits for the Purifi driver.
Purifi mostly excels in higher cone excursion in combination with low IMD when used fullrange (low + mid).
When just being used used as a mid, these advantages dissappear quickly in my experience.
Also maxSPL isn't as great as you might think.
I think you're running close to what's practically possible with 4 inch mids/woofers.
Great looking speaker btw and very nice approach to it all!!
That's basically just professional level.
(or better, I have seen companies doing a lot worse)
Crossing them a little higher could help a bit, but it might not work out well with the woofer.
A 5 inch will have a lot more in sense of sensitivity as well as max power, therefor a much higher maxSPL as well as lower distortion.
But the penalty will be an higher directivity, therefor it will sound different.
I personally also wouldn't use them anymore without a waveguided tweeter, since the directivity mismatch.
In this particular system, I don't see many benefits for the Purifi driver.
Purifi mostly excels in higher cone excursion in combination with low IMD when used fullrange (low + mid).
When just being used used as a mid, these advantages dissappear quickly in my experience.
Also maxSPL isn't as great as you might think.
I think you're running close to what's practically possible with 4 inch mids/woofers.
Great looking speaker btw and very nice approach to it all!!
That's basically just professional level.
(or better, I have seen companies doing a lot worse)
Hi b_force, thanks for your thoughtful additions.
Yes thats why i took the Kartesian Mid120 - it was the one in my simulations, and from construction features that promisted to give me the most undistorted and uncompressed dynamic headroom. From its properties, it reminds me of a Faital M5N8, Sica 5M1.5PL and other dedicated PA mids just shrinked in size.
The result has proven my hopes, the mid/tweeter unit can e.g. play a well and dynamically recorded Lang Lang piano concert subjectively louder than "in reality" at ~3 m listening distance in a 40m² room until it hurts in your ears but is still free of distortion or compression, just loud. You start to fear that the tiny drivers may burn, but they deliver clear and calmly.
Best regards
Peter
Yes thats why i took the Kartesian Mid120 - it was the one in my simulations, and from construction features that promisted to give me the most undistorted and uncompressed dynamic headroom. From its properties, it reminds me of a Faital M5N8, Sica 5M1.5PL and other dedicated PA mids just shrinked in size.
The result has proven my hopes, the mid/tweeter unit can e.g. play a well and dynamically recorded Lang Lang piano concert subjectively louder than "in reality" at ~3 m listening distance in a 40m² room until it hurts in your ears but is still free of distortion or compression, just loud. You start to fear that the tiny drivers may burn, but they deliver clear and calmly.
Best regards
Peter
Here some simple, rough max. SPL level simulations in Basta! based on datasheet parameters / TSPs on a H46xW23 cm baffle:
(Purifi Woofer with +/- 14 mm max. excursion and ideal port).
Purifi mid with optimistical 200W el. power limit for a 30mm VC (no datasheet value, they state pretty high numbers in general) , M74 with 150W, SB + Kartesian with 100W and 10F with 50W (datasheet says 30W). Purifi gets not louder than much cheaper SB12MNRX2, without considering distorion levels and commpression of course (here the Purifi may have its nose ahead, or not due to thermal compression - the efficiency is <= 4dB behind the other drivers, so it has to be pushed more).
You can also see that there is no real advantage in headroom in comparison with the Kartesian to using the PTT6.5 as a midwoofer (assuming that both have very low distortion), what you primary get is just the wider dispersion pattern matching the T25B without WG.
P.S.: This is what Clement from Kartesian has stated what applications he had in mind in some youtube comment below the presentation of his 4" drivers (translated from french to english via deepl):
(Purifi Woofer with +/- 14 mm max. excursion and ideal port).
Purifi mid with optimistical 200W el. power limit for a 30mm VC (no datasheet value, they state pretty high numbers in general) , M74 with 150W, SB + Kartesian with 100W and 10F with 50W (datasheet says 30W). Purifi gets not louder than much cheaper SB12MNRX2, without considering distorion levels and commpression of course (here the Purifi may have its nose ahead, or not due to thermal compression - the efficiency is <= 4dB behind the other drivers, so it has to be pushed more).
You can also see that there is no real advantage in headroom in comparison with the Kartesian to using the PTT6.5 as a midwoofer (assuming that both have very low distortion), what you primary get is just the wider dispersion pattern matching the T25B without WG.
P.S.: This is what Clement from Kartesian has stated what applications he had in mind in some youtube comment below the presentation of his 4" drivers (translated from french to english via deepl):
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Agree, but the M74 - at around $840 a pair - is considerably above my, self-imposed, budget. I can purchase a pair of PTT4.0Ms for around $500 and the Mid120s for around $380 or so.
I really appreciate this discussion. I've been wrestling with this midrange decision for quite a while and I feel like I'm finally getting the info I need to really make it well. Maybe I should start a separate thread so we can get back to the Schnuckelchens.
I'll try to come back to these questions this evening.
Or sell the purifi to purchase a Pure mid from them , and increase the woofer section which is less demanding on distorsion profile for the ears !
Your 6" seems tp be a midbass unit for 2 ways, maybe not something really suited to make a 3 ways with a 3" or 4" above ?!
Not better then to put the B34 in a WG and staying with the 6" ? Just asking...
Your 6" seems tp be a midbass unit for 2 ways, maybe not something really suited to make a 3 ways with a 3" or 4" above ?!
Not better then to put the B34 in a WG and staying with the 6" ? Just asking...
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Don't underestimate the Purifiy PTT6.5X extended stroke woofers. In a vented enclosure it will not stay behind the WO24P in CB that I use with my speakers...
@Paul:
It is one of the options you have with your stock. Purifi 6.5 + Bliesma with (e.g. Somasonus) WG OR additional small midrange. The first one will give a more narrow, CD-like dispersion (directivity increasing with frequency, example of the principle: https://www.diyaudio.com/community/...sb-acoustics-sb15nbac30-4.391310/post-7524440), the second one a wider, half-space dispersion (with some tradeoffs to make regarding the finite baffle size).
Let's come to some basic questions to find out what the motivation to change something is:
EDIT2: A vaild reason for the mid solution can also be: "I wanna keep the Bliesma because I like this cute thing, but I fear of ripping the grille. And I wanna use and squeeze out the Flex8 with its many channels, and learn to get a 3-way voiced" 😉 Totally fine for me as the solution with the mid is, I know such argumentations from myself...
It is one of the options you have with your stock. Purifi 6.5 + Bliesma with (e.g. Somasonus) WG OR additional small midrange. The first one will give a more narrow, CD-like dispersion (directivity increasing with frequency, example of the principle: https://www.diyaudio.com/community/...sb-acoustics-sb15nbac30-4.391310/post-7524440), the second one a wider, half-space dispersion (with some tradeoffs to make regarding the finite baffle size).
Let's come to some basic questions to find out what the motivation to change something is:
- I assume the setup with Purify Woofer + T25B is already running. What do you like and/or not like with the current configuration?
- Did you take some measurements from the setup you can show us? Do you have some Drawings, Pictures, Xover design?
EDIT2: A vaild reason for the mid solution can also be: "I wanna keep the Bliesma because I like this cute thing, but I fear of ripping the grille. And I wanna use and squeeze out the Flex8 with its many channels, and learn to get a 3-way voiced" 😉 Totally fine for me as the solution with the mid is, I know such argumentations from myself...
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Wonder also for Paul about the MS60D from SB Acoustics : 2.5" as a filller driver from 1 k to 3.5k with the T25B after.
Uh, SB has a lot of nice drivers with very good value, but I really don't like that thing:
Large diameter, but cannot be used below 1kHz due to high distortion caused by failed rear chamber design. Unnecessary large front panel that avoids close CTC spacing with the tweeter, that had been benefical for higher xover frequencies. Yes, a "filler driver" because it cannot be used low as cannot be used high. SB missed a lot of chances here in my eyes...
For a few bucks more, Kartesian Mid120 has many advantages, better design and better performance in comparison.
This one costs less, has small front panel and can be used from 800 Hz upwards although it has a bit smaller voicecoil/membrane:
https://www.morelhifi.com/product/mdm-55/
https://www-hifi--selbstbau-de.tran...l=auto&_x_tr_tl=de&_x_tr_hl=de&_x_tr_pto=wapp
Large diameter, but cannot be used below 1kHz due to high distortion caused by failed rear chamber design. Unnecessary large front panel that avoids close CTC spacing with the tweeter, that had been benefical for higher xover frequencies. Yes, a "filler driver" because it cannot be used low as cannot be used high. SB missed a lot of chances here in my eyes...
For a few bucks more, Kartesian Mid120 has many advantages, better design and better performance in comparison.
This one costs less, has small front panel and can be used from 800 Hz upwards although it has a bit smaller voicecoil/membrane:
https://www.morelhifi.com/product/mdm-55/
https://www-hifi--selbstbau-de.tran...l=auto&_x_tr_tl=de&_x_tr_hl=de&_x_tr_pto=wapp
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I also want to use the M5N8-80 as a midrange driver with a 12-inch bass driver (....but I just suffer from a chronic lack of time....🙄).
However, I don't think you can keep to this rule of thumb with the M5N8-80. I estimate that it can be used from around 400 to 500 Hz. Its Xmax is quite small, but that doesn't matter if you use it at such higher frequencies.
Kind regards
Michael
I've been hesitant to continue to hijack this thread, but I'm also not ready to start my own design thread. Here's what's going on...
I will be designing and building what will likely be my last speaker for myself. The design goals are a full range, low-distortion, highly dynamic system that is preferably on the smaller size (not a "monkey coffin"). In my typical fashion, it will take me years to finish this system. So far, I've purchased the PTT6.5s and the T25Bs and CSS SDX12s. On the electronics side, I've got the MiniDSP Flex8 and a 6 channel Hypex NCX02 based Buckeye Amps amplifier (4 channels via 2 NC502s and 2 channels via a NC252). At the time of purchasing the amp, I planned for a 3 way. Now that I'm planning on using a midrange, I'll have to buy 2 more channels for the SDX12s.
I listen to classical music with a bit of jazz, classic rock and folk thrown in.
The only thing I really care about regarding the "look and feel" of the midrange is that it not be too difficult to route the cut-out for it. Speaking of that, I'm not interested in a waveguide for the T25Bs because I don't want an exposed fragile beryllium dome. Also, I have fairly severe essential tremor so the idea of mounting a waveguide on top of the exposed dome terrifies me.
