I am also considering a bookshelf 3 way speaker and the drivers are quite close to yours for the high and mid. I am considering the Bliesma T25B and the M74S. If I am not wrong the ATC mid driver is also a soft fabric dome midrange, so I am more geared towards the silk version. As for the woofer, I am having a difficult time deciding whether to go for a 12" woofer or a smaller 8" woofer. If you planned on keeping the box small, the 8" woofer from Purifi is a good choice. I heard the bass from this driver is very good and in the end you might not even need a sub with the 8" Purifi woofer.
Getting one of the best midrange speakers with extra wide sound emission and then put the tweeter in a waveguide? You would produce an uneven radiation on purpose. Don't do that.
*) You could put BOTH domes in a big waveguide.
*) You can use a fitting mid driver which fits in beaming to the waveguide (better the WG fits to the mid driver)
*) You can enjoy the wide and consistent spreading of the domes as they are and have very similar sound all over the room. But your room should sound good for that, otherwise some directivity could be better.
Seas ER18RNX are very good up to about 1kHz. Good sensitivity and about 80Hz in a closed chamber when I remember right. THD is very low. To cheap for HighEnd of course ... ;-)
Did you thought about 2 6" drivers? Sensitivity of these Bliesmas is huge!
When 8" is ok for you I can tell you some semi-PA drivers with good sensitivity and very low THD and fine resolution at low levels. WO24P also looks great but more for fullrange. (As are ScanSpeak 8" - the ones with metal membrane have incredible low THD but a little waste when only go down to 80Hz). But for normal listening volumes these are all fine.
Btw - I did a listening comparison between the M74A and S, there is a thread here in the forums. I prefer the A cause I want precision from a mid dome. But for enjoying listening the S is perfectly fine. I'm waiting for the B but Bliesma doesn't get the membranes at the moment.
Tweeters - I would not go for the S, simply cause it's not working as a perfect cone up to 20kHz. The A is, and even better the B. A has very broad radiation, you can stand wide off axis and still have the complete hf information. But I prefer ther Beryllium version, it's a marvel in my opinion. The speaker get's expensive anyway - so ... 😎
Baffle - I use 25mm radius on all my corners which helps to flatten the responses. The router was not supercheap but it stays and in terms of the over all costs for this project ... recommended. Do a baffle simulation and find the best positions, don't do compromises here.
And - be careful what electronic you use in front of the mid dome! It is very sensitive and a noisy source will produce noise in your room. My rooms are very silent and I sit close, but a MiniDSP + tube amp would not cut it for me.
Gaaah! The build is getting more and more expensive! Haha
Looks like the Seas ER18NRX drops of a lot more than the other drivers I have mentioned in the lower region.
I the latest sketch the mw19p woofers 7" have an outer diameter of 187mm, a 8" beyma is 212mm so I guess you could make that work without changing the proportions massively. So any suggestions to 8" are welcome as well.
Nice to hear your impressions of the m74A and S. I read the same thing in an review, and according to the reviewer the P was kinda in between. Sounds good to me, I prefer a little softer sound. That's one of the reasons I did not consider the Be tweeter. But with the dome midrange extending high in the frequency range a little "sparkle" on top might not be a bad thing. Make me save some money on the woofer and maybe I'll make it happen!
I have a minidsp 2x4hd and have not had any issue with noise. I have a linear power supply, that might help over the wall wart switching supply. The flex eight should be quieter. I have mostly heard people think the bigger 4x10 and 10x10 minidsp introducing noise. One of my tube amps i quiet enough to power my Audeze lcd-x at 103db/mw 2cm from my ears without much hiss so I hope the bigger one will be fine as well. I get a small hiss from the tweeter on my current speakers, but only if i have my ear 10-15cm from the driver, and I don't think any of my other amps have been quieter.
Big thanks for the advice.
Looks like the Seas ER18NRX drops of a lot more than the other drivers I have mentioned in the lower region.
I the latest sketch the mw19p woofers 7" have an outer diameter of 187mm, a 8" beyma is 212mm so I guess you could make that work without changing the proportions massively. So any suggestions to 8" are welcome as well.
Nice to hear your impressions of the m74A and S. I read the same thing in an review, and according to the reviewer the P was kinda in between. Sounds good to me, I prefer a little softer sound. That's one of the reasons I did not consider the Be tweeter. But with the dome midrange extending high in the frequency range a little "sparkle" on top might not be a bad thing. Make me save some money on the woofer and maybe I'll make it happen!
I have a minidsp 2x4hd and have not had any issue with noise. I have a linear power supply, that might help over the wall wart switching supply. The flex eight should be quieter. I have mostly heard people think the bigger 4x10 and 10x10 minidsp introducing noise. One of my tube amps i quiet enough to power my Audeze lcd-x at 103db/mw 2cm from my ears without much hiss so I hope the bigger one will be fine as well. I get a small hiss from the tweeter on my current speakers, but only if i have my ear 10-15cm from the driver, and I don't think any of my other amps have been quieter.
Big thanks for the advice.
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Yes, you hear a lot of good things about the purifi woofers, but god they are pricey! It's also the old question about choosing excursion or membrane area for deep bass extension. A 8" purifi and a t34b would probably make one hell of a two-way.
One of the ideas when I started thinking about this build was to keep the drivers as small as possible but not stressing them. And to do that I landed in the idea of the three way and subs, a four way.
Really nice looking speaker Hydrogen Alex! I really like that you see the ply on the sides.
What driver are you using for hf above the beyma?
Unfortunately for me the width is what's most important to keep at a minimum. A projector screen is coming down between the speakers.
But the more I think, and the more perspective, ideas and inspiration I get from the community the further away I get from the original idea, hopefully/probably for the better 🙂
What driver are you using for hf above the beyma?
Unfortunately for me the width is what's most important to keep at a minimum. A projector screen is coming down between the speakers.
But the more I think, and the more perspective, ideas and inspiration I get from the community the further away I get from the original idea, hopefully/probably for the better 🙂
Seas midwoofers never match e.g. Revelators for low-end, but don't forget that their datasheets are shown with baffle loss applied as they're measured in a box so that the designer has an idea what system SPL to go for. http://seas.no/images/stories/about_seas/TEST_BOXES.pdf
The 7" driver test box dims are 215mm W x 320mm H x 265mm D.
If you're high-passing them to subs, what they do below, say 100hz, is not that important. You're really more interested in upper bass and lower-mid chops, and the ER18 has been used in several nice designs.
If you like that softer and classic paper sound, then the 18W-8545-01 is known for this.
Though it seems like you need to just mull on sketches of the different driver widths and decide what ultimate system sensitivity you're OK with.
I tried some passive XO sims with the T25S and it has a weird, non linear top-end response; maybe DSP would make this moot, but it seemed frustrating and wonky compared to most.
The 7" driver test box dims are 215mm W x 320mm H x 265mm D.
If you're high-passing them to subs, what they do below, say 100hz, is not that important. You're really more interested in upper bass and lower-mid chops, and the ER18 has been used in several nice designs.
If you like that softer and classic paper sound, then the 18W-8545-01 is known for this.
Though it seems like you need to just mull on sketches of the different driver widths and decide what ultimate system sensitivity you're OK with.
I tried some passive XO sims with the T25S and it has a weird, non linear top-end response; maybe DSP would make this moot, but it seemed frustrating and wonky compared to most.
Good to know!
Yep, hopefully I get time this weekend to do a few sketches with different baffles and driver sizes. I might bring home som material to build some mock ups in cardboard or similar. I have an open floor space apartment so speakers will be visible from everywhere except my bedroom.
I think the t25S is now out of the equation.
Talk about larger high efficiency woofers and praise of the bliesma BE tweeter makes me wonder if i should shift priority from the mid dome to higher end tweeter (t34b?) and woofer instead. Something to sleep on.
I just like to do things a little differently, for better and for worse. But maybe there is a reason you more often see a two way and not 3-ways with dome mid..
Yep, hopefully I get time this weekend to do a few sketches with different baffles and driver sizes. I might bring home som material to build some mock ups in cardboard or similar. I have an open floor space apartment so speakers will be visible from everywhere except my bedroom.
I think the t25S is now out of the equation.
Talk about larger high efficiency woofers and praise of the bliesma BE tweeter makes me wonder if i should shift priority from the mid dome to higher end tweeter (t34b?) and woofer instead. Something to sleep on.
I just like to do things a little differently, for better and for worse. But maybe there is a reason you more often see a two way and not 3-ways with dome mid..
Don't rule out the T25B; it seems much easier to work with.
All said, you generally don't get as much bang for the buck with a compact 3-way vs a 2-way of similar size, but the promise is better sound in the mid-dome's passband.
All said, you generally don't get as much bang for the buck with a compact 3-way vs a 2-way of similar size, but the promise is better sound in the mid-dome's passband.
Possibly a very shallow wave guide, to optimise top octave DI control, without mismatch at the crossover, the mid will still have a higher DI at the crossover due to a wider dome than the tweeter, so some level, although minor, of DI control should be used on the tweeter imo.
Thanks, I am really happy with them!
The "full range" actually is good for 100Hz to 15 Khz with a wee bit of Eq, I bout the last batch of them from Overkill Audio, they are a unique design based on the BMR principal but taken to extreme...details here http://custominstallaudio.com/ They are the best single driver I have ever heard. In a perfect world I want to use them over around 400Hz to 6KHz with Beyma TPL 200 above and Beyma 15 inch bass mid below... One day!
For 8 inch try the superb 18 sound https://www.eighteensound.it/en/products/lf-driver/8-0/8/8NMB420 4, 8, or 16 Ohm and really awesome in small sealed box.
You probably got a wrong idea of the tweeters - the aluminium version is the sparkly one, the Beryllium is very natural! It reminds me to the sound of a ring radiator, relaxed and without resonances. But with better directivity and less 2nd harmonics. The A version pronaunces a little for e.g. cymbals and details are easy to hear - but not harsh. B is more relaxed but still with all the details.
I will also chose Beryllium for my reference design in the mid band but not sure if this is needed when crossing in the 2kHz area. Will try and report as soon as I get some. A friend uses the paper version and likes it but we did no comparisons.
Noise - don't forget the M74 is 8-10dB more sensitive as your normal speaker! When you can hear hiss in 30cm distance you probably will hear it with this driver on your listening position. Most electronics are fine with 86dB sensitivity. But with 95dB things change. For my home cinema horn driver even the Hypex modules are on the edge for noise. It's ok for the living room but in my listening room (is more silent/isolated) it would be to noisy already.
The Seas ER 18RNX has higher sensitivity - but doesn't go as deep. That's what you want for your design? THD is lower as the other Seas up to 1kHz, would say it's Scan Speak quality. Will have a look if I find measurements - tomorrow.
With 2 6" you would get an interesting looking speaker and get enough output to come closer to the dynamic range of the M74.
I will also chose Beryllium for my reference design in the mid band but not sure if this is needed when crossing in the 2kHz area. Will try and report as soon as I get some. A friend uses the paper version and likes it but we did no comparisons.
Noise - don't forget the M74 is 8-10dB more sensitive as your normal speaker! When you can hear hiss in 30cm distance you probably will hear it with this driver on your listening position. Most electronics are fine with 86dB sensitivity. But with 95dB things change. For my home cinema horn driver even the Hypex modules are on the edge for noise. It's ok for the living room but in my listening room (is more silent/isolated) it would be to noisy already.
The Seas ER 18RNX has higher sensitivity - but doesn't go as deep. That's what you want for your design? THD is lower as the other Seas up to 1kHz, would say it's Scan Speak quality. Will have a look if I find measurements - tomorrow.
With 2 6" you would get an interesting looking speaker and get enough output to come closer to the dynamic range of the M74.
I helped a fellow member design a shallow waveguide to solve a problem of matching the T25B to the M74B. The Augerpro waveguide had too much directivity to match the M74B and using it in a flat baffle suffered from diffraction effects.
Waveguide and T25B measures like this
A 5mm deep plain radius was enough to match them quite well at 3K. The measurements are not mine so I have snipped the relevant bit.
How much vertical baffle there is above the M74 is important to avoid some unfortunate diffraction effects. Centred on a baffle wide enough for 8" drivers and 1" roundover works fine if the vertical is chosen carefully.
To the OP, when looking to have the drivers produce similar acoustic output do not forget the baffle step. Even with two mid woofers it will be hard to fully match the M74's sensitivity after the baffle step has been compensated.
T25 B and M74 P is a combination I have thought about long and hard 🙂
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I'm useing a way deeper crossover frequency between M74 and T25B around 2kHz. In this area the M74 still radiates very wide and transition works well.
If you need higher max SPL I would switch to T34B. The M74 is a beast in SPL, a 25mm tweeter is not able to compete.
Next step would be a combined waveguide, M74 + T34B ... 😎
If you need higher max SPL I would switch to T34B. The M74 is a beast in SPL, a 25mm tweeter is not able to compete.
Next step would be a combined waveguide, M74 + T34B ... 😎
Yep, the t34b felt expensive when I started looking for parts, but its gets more and more interesting..
What kind of crossover do you use in your speakers? I have never designed a passive crossover, but the community seems very helpful here so maybe it wont be any problem. It does free up a little money in the budget when no minidsp (800 eur) and a lot less amplifiers. I'm thinking of maybe start with the 18sound 8NMB420 and a t34b for starters, and get a little feel for them. The 8NMB should work well up a little higher in the frequency range and the t34B seems to be able to cross fairly low. Then wait for M74B when they get in stock. Maybe to get your impressions of it aswell!
I have actually had the 8NMB420 on the radar for a little while since I have seen it in other builds. Should I call that fate?
Thanks for sharing your experience.
Maybe I should let you finish your build first so I can learn from you what works and what doesn't! It will probably save me some time and headache 😉 And maybe some cash.
Not necessary so. It really depends on what kind of inductor, resistor and capacitor you are going to use for your crossover components. For capacitor alone, if you are using the slightly better range like the Jantzen Audio Superior Z Capacitor, that will cost you quite a bit for a 3 way crossover circuit. And every time you decide to tweet the crossover point or the response curve, you got to spend more on different value capacitor, inductor or resistor.
I use the Hpex active modules. I don't love their software but in terms of sound they are top notch! Very low noise what is important for my projects (sitting close with high sensitivity chassis). Sound quality is for sure higher as some mini DSP with some power amps, the parts are correctly gain staged and you get about 115dB S/N with the digital inputs.
18Sound 8NMB420. While a nice driver for PA I wouldn't recommend it for HiFi. THD is very high at low levels, it's not made for that. It was the first driver I tested for my home cinema speaker ... after all I bought and tested about 10 different ones ...
Endet up with PHL or Kartesian Audio - both great for HiFi and high level.
When you go 10" (PHL?) you probably can use it later with the M74 in between.
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Interesting comparison IamJF, thanks for posting. I love the PHL 1130 https://en.toutlehautparleur.com/speaker-phl-audio-1130-16-ohm-6-5-inch.html but I have never used their 8 inch bass mid.... Looks nice though!
Holy hell you are a goldmine.
The flex eight is a new product from Minidsp, specified SNR @128dB(A), THD+N @ -111dB (0.0003%. Even if they may not meet the spec, I think it will be fine. But I have also considered the Hypex plate amp but I really like the flexibility keeping the dsp and amp separate. And I consider my tube amp almost like a ornament in my home! 🙂
I guess I see it as a future problem that I will have to solve later if the noise is a problem. My local hifi-dealer recommends my tube amp to Avantgarde horn speakers, so I still have my hopes up!
I think I have to go 10". Smaller drivers just don't seem to have sensitivity to match. Any drivers that performed well lower in the frequency range? Think no need for subwoofer, or I have my old subs but they don't sound great for music, but OK for movies. Specially in a small box. Ditching new subs allows for redistribution of funds again.
Or go for a MTM or WTMW?
Sorry if keep changing my mind, there is a constant battle in my head between the compromises that you have to make. As usual, the more you read and gather information, the less you realize you know.
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