Yeah, that's not a particularly good implementation (w/ the insulation).. BUT the cabinet volume looks relatively large and deep - which is excellent.
My recommendation is: also a large volume and deep enclosure, but move the cotton re-bond (insulation) toward the center of the cabinet (hanging) starting at least 3" away from the driver's magnet and then extending most of the length/depth of the cabinet (but not close to the cabinet's panels). Also, a bass-reflex design with the port tuning at least 2 octaves BELOW the high-pass of the crossover (..so that would be <75 Hz tuning freq. for a 300 Hz high-pass). Note that the interior bass-reflex pipe should also not have insulation near its internal opening, and the diameter of the port should be "generous" in size. Finally, wax and buff the interior walls of the cabinet (and the bass-reflex pipe) to further reduce air-drag.
In effect then you've got reflections suppressed by the sound bouncing off of the walls and into the center-mass of the re-bond. There is overall lower friction that would damp the driver's motion in the sub mm range. Finally, there is an air load on the driver's resonance (from the bass-reflex) that damp's the motion of the driver where it is most non-linear and because of its low freq. tuning relative to its high-pass filter - is NOT designed to extend the lower freq. response of the driver (which would increase excursion and resulting distortion).
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Ow, that's BRUTAL! 😱😊
Yeah, the aerogel from Audax can "fatigue" and crack more easily. It's basically an acrylic foam with a polymer "skin" as the substrate for the foam (usually the front of the driver with no "skin" on the back).
My 170ZO's are still OK but then they have been in their boxes for almost a decade now (away from UV radiation). (..projects come-and-gone, where I cannibalized other drivers used with them for yet another project.)
Your right if we only talk about where we human hear sounds best, that is from range 1-5 K. ( to survive the best at the savann)
But my point here was that most instruments and what we hear "and analyzing" and are "real" sensitive to is between 1-2 k
We also talking about hifi and stereolistening and midrange here, and youknowyou´s xoverpoint at 1600hz.
Because now from 1600hz and up youknowyou´s tweeter has all "the responsibility"
Test if you raise the curve in your xover +2-3dB between 1-2 K, and you will likely experience the unwanted nasal cheap sound.
/Jawen
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Wonder how has the best knowledge here Scott 😉 ( no offence )
The man Albert behind this solution is my idol, and in some way also Arnie Nudell, Dan D'Agostino and Nelson Pass.
Albert was in the "industri" seen as "the best" magician on the planet, regarding to drivers knowledge and drivers implementation in a box and at building xover´s.
Designed transducers and crossover systems for audio companies including Klipsch, Polk, Infinity, Apogee, JBL, and many others.
Served as a consultant for companies such as Lucas Film THX, Walt Disney, Steinway, A&M Records, Sheffield Lab, Mobile Fidelity, and JVC.
Here his story in short at Stereophile magasine after he past.
https://www.stereophile.com/content/renaissance-man-damon-von-schweikert-albert-von-schweikert
You can reach "hifi-Nirvana" in different way´s, and no way is the wrong way...just different thinking.
/Jawen
Yeah, the aerogel from Audax can "fatigue" and crack more easily. It's basically an acrylic foam with a polymer "skin" as the substrate for the foam (usually the front of the driver with no "skin" on the back).
Yea, and you are right its no "skin" at the back of the cone.
The first 2 times it cracked i glue´d it with cut out coffee-filter-parts 🙂 , and i coulden´t hear any negative effect after the fix.
But last time when i blow all 4 of them it was the coil´s
The thing is:
With real good sounding speakers, you don´t perceives the sound to be so loud as it actually is
/Jawen
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WOW, coils blown on a sealed MTM! That takes some "doing". 😊
(..btw, you might be surprised about loading the driver's in the manner I mentioned - I don't even think Laurence Dickie is quite as far a long this "path" as what I've suggested (..I'm pretty sure he still uses standard "fill" near the end of his t-lines for his tweeter and mid's).)
(..btw, you might be surprised about loading the driver's in the manner I mentioned - I don't even think Laurence Dickie is quite as far a long this "path" as what I've suggested (..I'm pretty sure he still uses standard "fill" near the end of his t-lines for his tweeter and mid's).)
Couldn't really say that without a lot more data..
If you want something a bit more linear within your operating passband, also consider the Enviee fullrange without whizzer. Though like the E21 it is a larger diameter driver than the Audax. It's also expensive.. (but so is the E21). Also note that the T/S parameters and cabinet volume characteristics will be wildly different (than the Audax).
http://enviee.de/en/basic/data sheet - enviee basic.pdf
Still, if I'm considering a mid. only 8" driver I'd probably gravitate to this Audax:
http://www.dibirama.altervista.org/...udax-hm210z10-mid-range-8-8-ohm-240-wmax.html
-and save a lot of money as well.
Again, something in the 6" mid. driver range at 96 db is more difficult to find that isn't similar (and perhaps in some respects inferior to). The usual suspects though will be from Pro *manufacturers, with SB Audience's NERO-6MRN150D perhaps being the most similar as a design evolution (but it's a bit more efficient so it likely won't be a "drop-in" replacement).
*18 sound, B&C, Beyma, etc.. Note that Faital Pro's cheaper 6FE200 is mechanically/electrically a bit different than those usual suspects, unfortunately it's also not quite as linear up to 1.6 kHz (nor a bit above that).
If you want something a bit more linear within your operating passband, also consider the Enviee fullrange without whizzer. Though like the E21 it is a larger diameter driver than the Audax. It's also expensive.. (but so is the E21). Also note that the T/S parameters and cabinet volume characteristics will be wildly different (than the Audax).
http://enviee.de/en/basic/data sheet - enviee basic.pdf
Still, if I'm considering a mid. only 8" driver I'd probably gravitate to this Audax:
http://www.dibirama.altervista.org/...udax-hm210z10-mid-range-8-8-ohm-240-wmax.html
-and save a lot of money as well.
Again, something in the 6" mid. driver range at 96 db is more difficult to find that isn't similar (and perhaps in some respects inferior to). The usual suspects though will be from Pro *manufacturers, with SB Audience's NERO-6MRN150D perhaps being the most similar as a design evolution (but it's a bit more efficient so it likely won't be a "drop-in" replacement).
*18 sound, B&C, Beyma, etc.. Note that Faital Pro's cheaper 6FE200 is mechanically/electrically a bit different than those usual suspects, unfortunately it's also not quite as linear up to 1.6 kHz (nor a bit above that).
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You still haven´t tell us the answer on these questions.
What woofer do you use and what hornloaded ribbon ?
Have you tried driving the M0 up to 1,8-2 K ?
And can´t have a opinion on the wideband E21 LB 15 Cu, because never heard of it and hardly no data available
/Jawen
I use a Eminence omega pro15a as a woofer, but i will be ordering some Beyma SM-115N and Beyma 15LX60v2 to compare.
my planar tweeter is the hivi rt2ha. im trying to get the PAP-108 horns to compare but cant.
I didnt try to fine tune the sound as its sublime. i therefore dont feel like i must tinker with the xo, and just play with different midrange. that said, i will order a couple of coils and plan on trying to raise the xo a little (mostly to make sure the hivi is always happy)
many thanks with your detailed explanations
I guess audax it is
ll probably try one of their 8" mid to compare
then if i still prefer the PR170MO, ill start to learn how to modify the unit
I know westlake modify theirs unit, as well as sd acoustics SD1 speaker which i think treated the cone with C37. I will try the glue pattern ala scan speak, along C37 enemosser.
ill add measurements along the way.
I don't think the Beyma 15" driver's will do anything better than what you already have. The LX60 should provide a bit more "weight" or "heft" in the upper bass than the 15a, but that's about it, and perhaps slightly inferior with detail retrieval. (Mms of the driver's would show most of those differences.)
Considering the rt2ha has a bit of "lift" on the low-end (1.5 to 3 kHz), the faital pro 6FE200 might work well with perhaps a 1st order electrical around 2.7 kHz. Detail retrieval won't be as good as the Audax but the driver does have some "charms" of its own and doesn't cost a lot to try out.
-really though, finding better would require a different design (and other than harmonic distortion the design is already quite good).
I'd almost say, add 2 more rt2ha's per channel and go the 4x 4" Audax aerogel drivers in a side-by-side small vertical line array (as long as you don't listen in the nearfield). Different design though..
Considering the rt2ha has a bit of "lift" on the low-end (1.5 to 3 kHz), the faital pro 6FE200 might work well with perhaps a 1st order electrical around 2.7 kHz. Detail retrieval won't be as good as the Audax but the driver does have some "charms" of its own and doesn't cost a lot to try out.
-really though, finding better would require a different design (and other than harmonic distortion the design is already quite good).
I'd almost say, add 2 more rt2ha's per channel and go the 4x 4" Audax aerogel drivers in a side-by-side small vertical line array (as long as you don't listen in the nearfield). Different design though..
The SB Audience 15 bianco something made for OB, and if the T&S are acurate, could make a nice sealed as well.
yeah, i also think the Omega pro15a and the SM-115N and LX60 should all near identical. I think the LX60 will be prefered as its ever so slightly more efficient or rather more flat betwenn 100 to 300hz rather then slight depression in the SM-115N or omega pro. More weight will be interesting.
I plan on building 2 more versions. a exact copy of what i have but in a smaller cab (around 90L) and a Geithain quasi-coaxial version in a same size cabinet.
so all of those woofers will eventually find a place.
The SM-115N will probably work better in a smaller cab then my other two woofers.
Maybe you can consider the 5 or the 7" from EMS speaker (but simple magnet line)? They are distributed in Canada and this is Fertin (the man) behind.
http://www.emspeaker.com/ems_products.html
http://www.emspeaker.com/ems_products.html
This Beyma 12 inch is quite interesting....and cheap at 105 Euro!
https://en.toutlehautparleur.com/speaker-beyma-12br70-8-ohm-12-inch.html
http://www.loudspeakerdatabase.com/Beyma/12BR70
Maby use x2 per side 👌💪
/Jawen
I think it has no room on hi baffle for 12 in spite of the 17PM0. Not sure the 12 will fill better the 1.8k to 3 k hz of the Hivi planar he also uses. He has asked elswhere iirc about the 17 as he bougth a Phl which was said to be close but isn't and eventually about a 15" as well if I am not wrong.
The hm21z0 Scott talks about seems to have a scary sensivity, however I do not see how it could be crossed easily vetween 2k and 3khz, last being advised by Hivi. But youknowyou is also listening to in room so does not need all the spl headroom like in a livingroom... I really think the tonal pleases him, however the soundstage is maybe suffering from a dip around the cut off ?
The hm21z0 Scott talks about seems to have a scary sensivity, however I do not see how it could be crossed easily vetween 2k and 3khz, last being advised by Hivi. But youknowyou is also listening to in room so does not need all the spl headroom like in a livingroom... I really think the tonal pleases him, however the soundstage is maybe suffering from a dip around the cut off ?
When I mentioned the HM21ZO it wasn't to suggest using it with the HiVi tweeter - rather take the statement on it's own:
"..if I'm considering a mid. only 8" driver I'd probably gravitate to this Audax".
Really it's to *loud and has to much off-axis pressure loss relative to HiVi. Plus any 8" driver is moving acoustic center further from the tweeter because of its larger diameter - with the potential for greater combing (..though with listening distance and angling the drivers vertically you could mitigate this for a certain listening position).
*the SB Audience 6" driver is also to loud and would require a filter to get a good match.
"..if I'm considering a mid. only 8" driver I'd probably gravitate to this Audax".
Really it's to *loud and has to much off-axis pressure loss relative to HiVi. Plus any 8" driver is moving acoustic center further from the tweeter because of its larger diameter - with the potential for greater combing (..though with listening distance and angling the drivers vertically you could mitigate this for a certain listening position).
*the SB Audience 6" driver is also to loud and would require a filter to get a good match.