Hi IamJF, I like your aproach to design. Best design usually indeed come from form to function, but sometimes we have "curiosity" we just have to satisfy. After some years thinking about it, when you finally have your driver in your hands it is like chapter in your life has been fulfilled, whether the object will satisfy you or not.. (Usually not.)
Anyway, did i understand right that you are talking about textreme m74 here? If yes, do you have experience how it differs to other dome materials?
My own personal goal is beautiful lies for home listening, so im looking for paper or silk, but textreme also intrigues me..
Yes, M74T. I didn't had one here for now. But I trust the HiFi Compass measurements it it looks very similar to the Alu version: https://hificompass.com/en/speakers/measurements/bliesma/bliesma-m74t-6
I have experience with the Textren Satori speakers and always liked what I heard - these are excellent drivers.
Go with silk when you actively search for a nice listening effect!
The difference to a hard dome is not like night and day, there is still plenty of detail and big dynamics. When entering a room you would not be able to hear immediately that it's a silk midrange. But it's audible when you do 1:1 comparison and for sure nicer when listening longer.
I would expect Textreme to be very similar to the hard domes, just a little more "laid back". Maybe a little more "natural" as the Alu dome. Not sure if you really could hear a significant difference in a 1:1 blind test in a speaker with tweeter. At least it looks cool and doesn't cost as much as Beryllium 😎
The silk dome M74S is definitely a bit more veiled than the metal dome A or B versions. There is decent low level detail retrieval on the silk version, but it quickly turns into more of a misty, haze as the levels go up. This is IMO a very suitable dome for classical music (string ensembles, acoustic nylon string guitar and solo vocals). There's just enough fluff added when the dynamics increase and it won't go super soft on you. For people who listen to older, more "flawed" recordings, this is your type of mid dome.
If you want decent dynamics with some forgiveness to source material integrity, along with a harmonic balance that doesn't change with volume, I'd always recommend at minimum the beryllium version. There is some cushion there to take the edge off of bad, over EQed recordings.
For all out detail and accuracy, the aluminum dome version is IMO the first choice. The M74A will stick anything back in your face, bad or good. It will also reveal less than decent D/A conversion and it's merciless to anything poorly recorded. I my tests I could clearly make out the type of top end filtering used in the playback D/A. You can actually hear azimuth errors and changes in VTA with vinyl playback, especially if your cartridge isn't dialed in properly.
If you have overly sensitive hearing in the top end, I'd pair the M74A with the T34B. This gives you some continuation of the midrange's character when transitioning to the tweeter, but not quite as edgy as the aluminum alloy T34A. The harmonic spectrum is very similar between the T34A and B. IMHO, Its well worth the extra money to get the T34B.
Regarding the ability of any version of M74 keeping up in the lower mids, I'd mostly agree with IamJF that a single mid will keep up with a very capable 10" or 12" when crossed around 500 hz. Depending on BSC and linearized FR on a chosen baffle, a single M74 will likely not be the first to run out of steam in the lower mids. It depends on the source material ie. final EQ, dynamics and crest factor to be a bit more specific. I'm hesitant to say that typical modern (over) produced music adheres to the typical power distribution rules of the music which was usually produced for the limitations of analog vinyl playback. The tables can turn (no pun intended) when playing back "thicker" sounding, modern recordings that have significantly more saturated lower mids. The spectral power distribution changes with this sort of material, especially when most of the driver's bandwidth is in a lower region of the impedance curve on most 2 way and some 3 way speakers, loading the amplifier more heavily.
You also have to factor in most LF drivers being thermally more robust in power handling due to more thermal mass being available for heat dissipation. This varies by model of driver, but compared to a dedicated midrange, even with a decently large VC, it won't have the ability to absorb as much heat from the VC conversion loss. It makes the mid more susceptible to power compression and thermal overload. Even though the driver can cope, it still may have to deal with a considerable loss in proportional output (compression) as power levels increase. A few hundred Hz here and there difference in HP frequency can make or break the situation for a midrange.
If you want decent dynamics with some forgiveness to source material integrity, along with a harmonic balance that doesn't change with volume, I'd always recommend at minimum the beryllium version. There is some cushion there to take the edge off of bad, over EQed recordings.
For all out detail and accuracy, the aluminum dome version is IMO the first choice. The M74A will stick anything back in your face, bad or good. It will also reveal less than decent D/A conversion and it's merciless to anything poorly recorded. I my tests I could clearly make out the type of top end filtering used in the playback D/A. You can actually hear azimuth errors and changes in VTA with vinyl playback, especially if your cartridge isn't dialed in properly.
If you have overly sensitive hearing in the top end, I'd pair the M74A with the T34B. This gives you some continuation of the midrange's character when transitioning to the tweeter, but not quite as edgy as the aluminum alloy T34A. The harmonic spectrum is very similar between the T34A and B. IMHO, Its well worth the extra money to get the T34B.
Regarding the ability of any version of M74 keeping up in the lower mids, I'd mostly agree with IamJF that a single mid will keep up with a very capable 10" or 12" when crossed around 500 hz. Depending on BSC and linearized FR on a chosen baffle, a single M74 will likely not be the first to run out of steam in the lower mids. It depends on the source material ie. final EQ, dynamics and crest factor to be a bit more specific. I'm hesitant to say that typical modern (over) produced music adheres to the typical power distribution rules of the music which was usually produced for the limitations of analog vinyl playback. The tables can turn (no pun intended) when playing back "thicker" sounding, modern recordings that have significantly more saturated lower mids. The spectral power distribution changes with this sort of material, especially when most of the driver's bandwidth is in a lower region of the impedance curve on most 2 way and some 3 way speakers, loading the amplifier more heavily.
You also have to factor in most LF drivers being thermally more robust in power handling due to more thermal mass being available for heat dissipation. This varies by model of driver, but compared to a dedicated midrange, even with a decently large VC, it won't have the ability to absorb as much heat from the VC conversion loss. It makes the mid more susceptible to power compression and thermal overload. Even though the driver can cope, it still may have to deal with a considerable loss in proportional output (compression) as power levels increase. A few hundred Hz here and there difference in HP frequency can make or break the situation for a midrange.
As to my small issue with my M74As, I've come up with a simple and effective fix. I've inserted a 0.5 mm stainless steel washer under each of the 4 flange screws. There is locktite on the threads, so go slowly and carefully when removing the screws to avoid thread damage. The small buzz was completely cured with this fix.
Thank you for writing that up, @IamJF . The conception of my needs and environment is pretty far along. I hope if I explain it, y'all can help with the excellent fundamental questions you outlined:
Main priority is music listening, not video at all. I want a sense of unrestrained dynamics to allow the unstrained reproduction of classical music. I don't want the anticipatory cringing or urge to go for the volume control as a climax approaches. I want crystalline, transparent to source, beautiful clarity without any (added) glare and am prioritizing minimizing resonances of all kinds (in drivers, no ports, etc.). The main priority is solitary listening in whatever is determined to be the "sweet spot" via measurements, but sounding reasonably good on the couch behind it while my wife and I watch her BBC shows and the occasional movie (the fairly small TV by modern standards is mounted high up, away from any first reflection points). No true near field listening (like monitors on a desk or from a meter away).
Room is very treated:
I want to minimize the influence of the room acoustics (clearly!) on the reproduction, instead hearing the acoustics of the original space in which the music was recorded. Not all music I listen to is acoustic instruments recorded in real spaces, but the best reproduction of those recordings is the most important.
I have decided, with this build, to move beyond 2 channels, but again, not caring about movies/video. I have done a lot of research on the best approach, coming to the conclusion that I like Gerzon's approach the best, read his patents, and am prepared to implement his Trifield, either by buying a used Meridian processor or implementing it in software. Atmos is all the rage, but I think I might start without focusing on discrete surround. I know the catalog is increasing, but I am not excited about listening at low bit rates and, most importantly, I want to listen to the specific conductors/orchestras/performances that I prefer, not based on the performances they decide to go back to and master for surround. Maybe I will add the capability in the future.
So the build I have been discussing here is for identing L, C, R channels. I will eventually add side channels based on his ideas, no room for rears.
So perhaps now you can see my dilemma re. choosing dispersion characteristics and a final design. I have traditionally preferred narrow (to minimize room contributions), but now in a well-treated room it seems wider dispersion would be reasonably accommodated. But conversely, with multiple channels and extracted ambience coming from the sides, narrow dispersion would work great, too.
I have 3 x T34Bs and now need to make my next purchase:
(I know you are a fan of the Hypex DSP/plate amps and convinced of their transparency, and they would certainly reduce complexity, but I am a bit nervous about their ultimate fidelity- wish they would update the amplifiers to their most-recent ones)
Hope this wasn't too long for everyone...
Bill
Main priority is music listening, not video at all. I want a sense of unrestrained dynamics to allow the unstrained reproduction of classical music. I don't want the anticipatory cringing or urge to go for the volume control as a climax approaches. I want crystalline, transparent to source, beautiful clarity without any (added) glare and am prioritizing minimizing resonances of all kinds (in drivers, no ports, etc.). The main priority is solitary listening in whatever is determined to be the "sweet spot" via measurements, but sounding reasonably good on the couch behind it while my wife and I watch her BBC shows and the occasional movie (the fairly small TV by modern standards is mounted high up, away from any first reflection points). No true near field listening (like monitors on a desk or from a meter away).
Room is very treated:
- All first reflection points absorptive
- Front wall is of acoustically transparent material in front of 35cm of insulation, this absorbing everything above ~ 70Hz. The main LF modes of the room are ~ 36 and 72 Hz. After implementing 5 sealed distributed subs my bass response is smooth enough that after painstaking measurements and adjustment, I only need to correct the lowest mode with one band of parametric EQ.
- The drywall on the ceiling was removed, exposing the attic above with several feet to the ceiling. It, too, is covered over the first reflection points to the MLP and couch with acoustically transparent fabric and insulation above. The rest of the periphery of the ceiling is air transparent diffusors (of the "MyRoom" approach).
- Sidewalls behind the first reflection points are diffusive
I want to minimize the influence of the room acoustics (clearly!) on the reproduction, instead hearing the acoustics of the original space in which the music was recorded. Not all music I listen to is acoustic instruments recorded in real spaces, but the best reproduction of those recordings is the most important.
I have decided, with this build, to move beyond 2 channels, but again, not caring about movies/video. I have done a lot of research on the best approach, coming to the conclusion that I like Gerzon's approach the best, read his patents, and am prepared to implement his Trifield, either by buying a used Meridian processor or implementing it in software. Atmos is all the rage, but I think I might start without focusing on discrete surround. I know the catalog is increasing, but I am not excited about listening at low bit rates and, most importantly, I want to listen to the specific conductors/orchestras/performances that I prefer, not based on the performances they decide to go back to and master for surround. Maybe I will add the capability in the future.
So the build I have been discussing here is for identing L, C, R channels. I will eventually add side channels based on his ideas, no room for rears.
So perhaps now you can see my dilemma re. choosing dispersion characteristics and a final design. I have traditionally preferred narrow (to minimize room contributions), but now in a well-treated room it seems wider dispersion would be reasonably accommodated. But conversely, with multiple channels and extracted ambience coming from the sides, narrow dispersion would work great, too.
I have 3 x T34Bs and now need to make my next purchase:
- M74A or T (or should I stretch to the B?) (with series notches at upper resonance) and woofers (dsp crossover 3-way) or
- Larger midrange and woofers (3 way)
- Top-class midwoofers to M74 (dsp or analog crossover to minimize amp channel count if it could be pulled off)
(I know you are a fan of the Hypex DSP/plate amps and convinced of their transparency, and they would certainly reduce complexity, but I am a bit nervous about their ultimate fidelity- wish they would update the amplifiers to their most-recent ones)
Hope this wasn't too long for everyone...
Bill
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Hey, hope this is okay to ask over here.
I am planning a 3 way studio monitor build and I definitely want to include a midrange dome for its clarity.
Came across an offer for two Dynaudio D54 06 for 200€ and I am wondering if there is a better option that would offer better performance for my use case (critical listening, 1m listening distance, no high SPL requirements, planning to cross over at around 3-400hz).
thanks
Vincent
I am planning a 3 way studio monitor build and I definitely want to include a midrange dome for its clarity.
Came across an offer for two Dynaudio D54 06 for 200€ and I am wondering if there is a better option that would offer better performance for my use case (critical listening, 1m listening distance, no high SPL requirements, planning to cross over at around 3-400hz).
thanks
Vincent
Im that guy ho pick drivers i like, and then build "a great" speaker with them.
Now 5-6 diyspeakers in, i got very good results in the end with all of them & would even use the term "top speaker" result on 80 % and "top notch" on one.
And that with "ordanary" drivers (exept 1 pair of Mundorf AMT)
Of course people ho lives on selling speaker, don´t "work" like me, just wanted to say it´s really doable 🙂
@Bill Brown You have the basics covered pretty well. My first choice to go with T34Bs would be the M74A. Its an all around nearly faultless mid that can be used in multiple ways.
The only real M74A caveat is that huge upper peak. It's readily dealt with using a passive series LCR right at the driver terminals.
You'll need to sweep every individual M74A to pinpoint the center frequency for the notch. It won't be symmetrical (ie. dead center), so some trial and error fiddling will be needed to dial in the notch filter as close as possible to obtain the best FR compromise across the effective range of only one notch. Be warned - the first time I heard the M74A breakup region, sweeping manually past 10k was a shocker. This peak is 16 dB tall above average output and when you hit that spot, it will sound like bad high frequency mic feedback, so use caution (hearing protection) when sweeping loudly.
A good starting place for the LCR is 3uF, 33R 15W, .06mH. Thats based on the 5.6 ohm driver DCR. Even if you go with DSP filters, its highly recommended using the passive notch. This stops any chance of HD modulated down into the lower bandwidth of the mid.
My choice for a good LF driver would depend on a few factors, but I'd recommend at least something with a decent motor with induction control and smooth FR past 800 hz. The textreme Satoris are nice, specifically the WO24TX, but they're pricy. The paper versions are also very good, but a little less detailed sounding. I also like the Audax HM210C0 and HM170CO for midbass. The aluminum SB drivers are also good. There's a lot of decent woofer choices these days. Eton has a few good ones as well. I'm a fan of higher sensitivity pro woofers if they have good motors with adequate induction control. Some of you guys have used the SB34NRXL, which is an excellent woofer, even with a higher LP cutoff. It has no issues with a 400 hz cutoff, but the enclosure contruction and dampened is tricky with larger woofers crossed this high. I was contemplating using the 2 pairs of SB34NRXL I had set aside for another project, but using 2 large LF drivers in a (.5) configuration is tricky with passive filters. It would require 2 extra amp channels with a DSP setup.
DSP plate amps would be a much easier solution with all these drivers, just not cheap. Hypex is good, but it requires a commitment to going purely digital, which wasn't going to work for my needs. If I were building this for HT and digital source listening, I wouldn't hesitate to go fully DSP.
The only real M74A caveat is that huge upper peak. It's readily dealt with using a passive series LCR right at the driver terminals.
You'll need to sweep every individual M74A to pinpoint the center frequency for the notch. It won't be symmetrical (ie. dead center), so some trial and error fiddling will be needed to dial in the notch filter as close as possible to obtain the best FR compromise across the effective range of only one notch. Be warned - the first time I heard the M74A breakup region, sweeping manually past 10k was a shocker. This peak is 16 dB tall above average output and when you hit that spot, it will sound like bad high frequency mic feedback, so use caution (hearing protection) when sweeping loudly.
A good starting place for the LCR is 3uF, 33R 15W, .06mH. Thats based on the 5.6 ohm driver DCR. Even if you go with DSP filters, its highly recommended using the passive notch. This stops any chance of HD modulated down into the lower bandwidth of the mid.
My choice for a good LF driver would depend on a few factors, but I'd recommend at least something with a decent motor with induction control and smooth FR past 800 hz. The textreme Satoris are nice, specifically the WO24TX, but they're pricy. The paper versions are also very good, but a little less detailed sounding. I also like the Audax HM210C0 and HM170CO for midbass. The aluminum SB drivers are also good. There's a lot of decent woofer choices these days. Eton has a few good ones as well. I'm a fan of higher sensitivity pro woofers if they have good motors with adequate induction control. Some of you guys have used the SB34NRXL, which is an excellent woofer, even with a higher LP cutoff. It has no issues with a 400 hz cutoff, but the enclosure contruction and dampened is tricky with larger woofers crossed this high. I was contemplating using the 2 pairs of SB34NRXL I had set aside for another project, but using 2 large LF drivers in a (.5) configuration is tricky with passive filters. It would require 2 extra amp channels with a DSP setup.
DSP plate amps would be a much easier solution with all these drivers, just not cheap. Hypex is good, but it requires a commitment to going purely digital, which wasn't going to work for my needs. If I were building this for HT and digital source listening, I wouldn't hesitate to go fully DSP.
If you look at the M74A curve, the upper peak is multi modal. This may be a result of the varying dome thickness across its radial profile. The technology required to make such an advanced diaphragm is significant and no doubt very impressive.
M74A -
M74B -
The M74B has a lighter diaphragm which shows up in the sensitivity specs. To my ears, the M74A is a little crisper and tighter sounding in the upper mids than the M74B. I'm not sure exactly why, but the slight downward FR trend on the M74A may indicate better internal dampening. Regardless of all this, both FR curves look equally impressive.
Based on cost alone, the M74A is a bargain. Most people don't understand it actually has a slight performance advantage in the lower mids to the beryllium M74B. This is partially due to a little lower Qms and Fs. The dome is dampened better radially where it terminates with the surround. Between both versions, when played very loudly, the M74A sounds just a tiny bit cleaner. Again, its a small difference, but its there.
M74A -
M74B -
The M74B has a lighter diaphragm which shows up in the sensitivity specs. To my ears, the M74A is a little crisper and tighter sounding in the upper mids than the M74B. I'm not sure exactly why, but the slight downward FR trend on the M74A may indicate better internal dampening. Regardless of all this, both FR curves look equally impressive.
Based on cost alone, the M74A is a bargain. Most people don't understand it actually has a slight performance advantage in the lower mids to the beryllium M74B. This is partially due to a little lower Qms and Fs. The dome is dampened better radially where it terminates with the surround. Between both versions, when played very loudly, the M74A sounds just a tiny bit cleaner. Again, its a small difference, but its there.
@Bill Brown There's really not that much difference between M74 variants regarding the notch treatment complexity other than having a single filter in the right place. It just takes a little trial and error. The aluminum alloy and Textreme versions are very similar in this regard.
You can smoke any speaker when you play it VERY LOUD.
Yeah, absolutely. Not hard at all. Just hook up a Crown Macrotech to a set of NS10Ms and break out the bag of marshmallows...
The Heco KMC38 and KMC51 were used in some A/D/S speakers. They're the same drivers based on older catalogs.
I just used the SB Audience Nero-12MWN700D in a 2cf (60 liter) 44Hz port box & can report it has good extension & snap down to just below 40Hz and smooth response up to just past 1khz. I'm using miniDSP 2x4 hd, and with +10 dB shelf at 80hz, Q=1, I didn't expect the quality of bass I'm getting. Steep LR8 filter at 30Hz to stop any low frequency overload; it plays very loudly without complaint. I'm crossing at 800Hz & the woofer is doing very well.
This would be a good candidate as a mid-bass driver in a 4-way OB, too.
Dueling guitars, dueling solos in harmony and counterpoint....
It was LOUD... you know, it gets loud, it gets to 11 and then it gets to where you actually FEEL IT.
Sansui was (is) rated at 90 wpc... the power meters were way UP... I think it was the right channel, if so, that was Freddie King's guitar that did it.
Amazes that the 2 inch dome did go up in smoke. In reality, it developed a heat issue... when it got hot it would cut out, but at normal listening levels you couldn't tell. I was in college then, so our normal listening level was.... 10.
I suppose if you're gonna play a midrange dome that loud you should use a metal dome that can dissipate more heat, huh?
I have seen powerfull cervin vega woofers go to speaker heaven when someone turned bass up on mix board while playing LOUD using 2500 watts behringer amp.
I smoked vintage Jensen midranges while playing VERY LOUD while smoking pot and listening to janis joplin.
And many other. Its not that hard. And does not mean speakers which gets smoked are inferior. Most of the time the operator is at fault and could have been easily avoided.
I smoked vintage Jensen midranges while playing VERY LOUD while smoking pot and listening to janis joplin.
And many other. Its not that hard. And does not mean speakers which gets smoked are inferior. Most of the time the operator is at fault and could have been easily avoided.
We used to be a Yamaha Pro warranty center, repairing alot of 1st gen 01R consoles, amps and speakers. There was a model of 15" that would catch fire at the VC and burn the cone. It was the woofer they used in their popular 3 way portable PA box. It had a large mid horn with a Foster CD. The fix was to install a fuse in the crossover to the woofer. A Crown DC300 driven to clipping was enough to make it fail.
Those ADS 3 ways weren't very durable for party use, as this was how alot of people would use them. It didn't matter whether it was a metal or cloth dome mid. The thermal capacity wasn't that great on a small mid like that. Woofers have more metal to act as a heat sink, so if the thermal conductivity was high enough, it would pull some heat away from the VC. An aluminum VC former helps, but it needs a place to direct the heat away from the VC.
More modern heat resistant materials and adhesives help push the power handling but you still had to deal with power compression. Woofers also benefit from VC excursion to circulate cooler air around the magnet gap. That can really boost power handling on smaller VCs that have some winding length on them. It doesn't do squat on a midbass or midrange playing mostly at its lowest point of the impedance curve, where the amp can dump some power into it.
Those ADS 3 ways weren't very durable for party use, as this was how alot of people would use them. It didn't matter whether it was a metal or cloth dome mid. The thermal capacity wasn't that great on a small mid like that. Woofers have more metal to act as a heat sink, so if the thermal conductivity was high enough, it would pull some heat away from the VC. An aluminum VC former helps, but it needs a place to direct the heat away from the VC.
More modern heat resistant materials and adhesives help push the power handling but you still had to deal with power compression. Woofers also benefit from VC excursion to circulate cooler air around the magnet gap. That can really boost power handling on smaller VCs that have some winding length on them. It doesn't do squat on a midbass or midrange playing mostly at its lowest point of the impedance curve, where the amp can dump some power into it.