I'm afraid i don't fully understand the question, so i'll answer to the best of my understanding. My goal was to make bookshelf that has good power response, controlled directivity, good phase response, flat frequency response and pass-band free of resonances with as benign impedance as i can - and all that in a conventional packaging with passive crossover.
Visaton waveguide handles edge diffraction higher in frequency, it moves acoustic center of tweeter closer to the midwoofer, it boosts frequency response bellow 10KHz to enable lower crossover point than usual and by that makes power response better without dip at crossover frequency, it lowers distortion. Only thing i could do better than this (that i can remember at this moment) is to use coaxial driver and make vertical off-axis identical to the horizontal.
I took an ordinary metal cone driver and ordinary silk dome tweeter to achieve (what i believe is) extraordinary result. I believe that biggest mistake one could make is to buy some drivers and stop with the design when it is good enough. I've tried to make this as close to perfect as the drivers and my knowledge would let me to, regardless of number of crossover parts or similar mumbo-jumbo. The crossover needs to be as big and complex as it needs, to handle all of the problems on and off axis, in my opinion.
Now that the cone resonance, characteristic for metal cones, is under -45dB (which is domain of harmonic distortion so i would guess quite undetectable) - i think i fulfilled my goal.
0,25uF with 1 ohm across the midwoofer coil is tank filter - or "not quite bottomless notch" at around 8KHz and serves to suppress the resonance even more than slope would do on its own.
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Hi Zvu,
Sorry I wasn't more clear, but your response was still illuminating. I was thinking more about the bass response in the bookshelves. I'm thinking about how you measured them and accounted for boundary reinforcement in the bass so that when you put them in the bookshelves they would be properly balanced.
Ty Re: 8kHz Tank.
Best,
E
Sorry I wasn't more clear, but your response was still illuminating. I was thinking more about the bass response in the bookshelves. I'm thinking about how you measured them and accounted for boundary reinforcement in the bass so that when you put them in the bookshelves they would be properly balanced.
Ty Re: 8kHz Tank.
Best,
E
Bookshelf by size not by role. Maybe i should have wrote "standmount". Their place is on the bookshelf only when my little daughter is in the room.
This is a full baffle step design with F3=45Hz and it merges with the room quite nicely. I did recommend (maybe not on this forum) that their placement shouldn't be in the corners but they don't mind being close to rear wall.
Thanks for pointing that out.
Cheers
This is a full baffle step design with F3=45Hz and it merges with the room quite nicely. I did recommend (maybe not on this forum) that their placement shouldn't be in the corners but they don't mind being close to rear wall.
Thanks for pointing that out.
Cheers
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Ty.
That was NOT a criticism by the way!
I think there is a place for stand-mounts and speakers that go onto bookshelves. The use of a waveguide, plus the picture made me (incorrectly) think you had envisioned them as on-bookshelf speakers to begin with, so I wanted to know about optimizations you might have done around that.
I did not mean to suggest the speakers lacked merit!
Best,
E
That was NOT a criticism by the way!
I think there is a place for stand-mounts and speakers that go onto bookshelves. The use of a waveguide, plus the picture made me (incorrectly) think you had envisioned them as on-bookshelf speakers to begin with, so I wanted to know about optimizations you might have done around that. I did not mean to suggest the speakers lacked merit!
Best,
E
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Why not buy some cheap aluminium cone woofer and experiment with it? I once thought about this and eyed the Dayton aluminium cone as it is cheap and has a pronounced breakup. I wanted to try the Scanspeak approach - cut slices in the cone and add polypropylene or some highly damping glue but aborted it as I am more keen on putting my cash into another experiment on creating a hard cone.
We'll see.
Whether it works or not, i definitely want another pair of L15. I really want to design MTM with it. I've read a ton of negative experiences and very few positive ones about MTM but i presume that the reason is (as often happens) poor design.
I've never listened any good implemented MTM such as Gryphon Mojo, Snell Illusion, YG Acoustics Sonja 1.3, anything from Golden Ear or similar. The ones i did listen i consider inadequate to say the least (bad implementation of lousy drivers).
Whether it works or not, i definitely want another pair of L15. I really want to design MTM with it. I've read a ton of negative experiences and very few positive ones about MTM but i presume that the reason is (as often happens) poor design.
I've never listened any good implemented MTM such as Gryphon Mojo, Snell Illusion, YG Acoustics Sonja 1.3, anything from Golden Ear or similar. The ones i did listen i consider inadequate to say the least (bad implementation of lousy drivers).
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I think one possibility is the choice of drivers and in some cases - the design flaws. A proper MTM would require a few prerequisites to be met:
1. Very close spacing between the midwoofers which might benefit from
* use nothing bigger than 4" with tiny frames
* small flange tweeter like the SB26STCN or even better without a flange and glue it to the baffle with some low-medium strength silicone so it can be replaced if needed
* offset the tweeter so woofers can be mounted even closer (besides the diffraction benefit)
* Y-dimension curved baffle would definitely help with comb effects (many pro arrays use this approach)
or
1. The use of a waveguide and a tweeter like the SB29RDC or the Monacor DT300 - in a 17-18cm waveguide both can take a 4th order LR down to 1.5Khz which allows 5" midwoofers to be used (I did it and it works, first dip from comb was at around 1.6Khz measured at +/- 30 degrees). I`m not home but can post a pic of the finished loudspeaker later.
2. Addition of supporting woofers, 6-7", to fill the gap but this makes the MTM pretty expensive as it will feature lots of drivers and crossover work will be a challenge
3. Listen to them from 2m or farther
Besides, the steep slopes an MTM usually needs mean higher gd and more crossover nonlinearities when you compare the input to the output signal, maybe another reason why you didn`t like them. I have not heard an MTM I like a lot either (even the one I mentioned above designed and built by me )
1. Very close spacing between the midwoofers which might benefit from
* use nothing bigger than 4" with tiny frames
* small flange tweeter like the SB26STCN or even better without a flange and glue it to the baffle with some low-medium strength silicone so it can be replaced if needed
* offset the tweeter so woofers can be mounted even closer (besides the diffraction benefit)
* Y-dimension curved baffle would definitely help with comb effects (many pro arrays use this approach)
or
1. The use of a waveguide and a tweeter like the SB29RDC or the Monacor DT300 - in a 17-18cm waveguide both can take a 4th order LR down to 1.5Khz which allows 5" midwoofers to be used (I did it and it works, first dip from comb was at around 1.6Khz measured at +/- 30 degrees). I`m not home but can post a pic of the finished loudspeaker later.
2. Addition of supporting woofers, 6-7", to fill the gap but this makes the MTM pretty expensive as it will feature lots of drivers and crossover work will be a challenge
3. Listen to them from 2m or farther
Besides, the steep slopes an MTM usually needs mean higher gd and more crossover nonlinearities when you compare the input to the output signal, maybe another reason why you didn`t like them. I have not heard an MTM I like a lot either (even the one I mentioned above designed and built by me
)
Please do. I'm always interested in that kind of stuff.
...I have not heard an MTM I like a lot either (even the one I mentioned above designed and built by me
What's the thing you didn't like ?
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