with no experience on these drivers i cant really make actual recomendations but i can give you my two cents, i think that a 3 way with the XT, the 3" mid dome (D75MX) and then the M18, maybe with a crossover of 750Hz and 4.5KHz. my reasoning behind this is that the lower midrange smoothness of the M18 should not be wasted.
what do you think?
what do you think?
Mmm, the experienced heads around here (not mine) might say that in it's price range (and somewhat beyond) there's nary a driver smoother from 300-3000 than the P13.
Besides, the idea of crossing the M18 lower rather than higher is to relieve it of the job of handling mids and hand that off to a specialty mid driver, as the P13 is considered.
Mos
Besides, the idea of crossing the M18 lower rather than higher is to relieve it of the job of handling mids and hand that off to a specialty mid driver, as the P13 is considered.
Mos
My company sells a kitset called the AKSonic with a complex, carefully engineered crossover using the Vifa M18 and the X25T ring tweeter in a two way.
This is an exceptionally good combination, with gorgeous imaging, unbelievable detail and wonderful engagement.
The M18 has a very strong motor (BIL of 7.5) with very high mechanical Q (6.7). This makes it place rather than play the note.
Recommended.
Cheers,
Hugh
This is an exceptionally good combination, with gorgeous imaging, unbelievable detail and wonderful engagement.
The M18 has a very strong motor (BIL of 7.5) with very high mechanical Q (6.7). This makes it place rather than play the note.
Recommended.
Cheers,
Hugh
Hi, Hugh
You think the M18 has good potential to be crossed over low in a 3 way?
The results I've got from LspCad show a good F3 of 35hz in a 55 litre box tuned to 34hz.
Michael:
I was thinking about the Vifa M22 8", built for smaller vbs and with and Fs of 26hz. It's just a lot more expensive, that's all, and when you're buying 4 woofers that can get out of hand.
--------
Furthermore, Keith Kidder (Hi, Keith) gave me an idea when he suggested that the Vifa M series drivers were a poor man's scanspeak.
If you try modelling the drivers, dual M18s, P13 and XT 25, they could be made to perform (and look
) like a poor man's Sonus Faber Cremona quasi-clone. Not quite the bang but nowhere near the buck.
Anyone?
Mos
You think the M18 has good potential to be crossed over low in a 3 way?
The results I've got from LspCad show a good F3 of 35hz in a 55 litre box tuned to 34hz.
Michael:
I was thinking about the Vifa M22 8", built for smaller vbs and with and Fs of 26hz. It's just a lot more expensive, that's all, and when you're buying 4 woofers that can get out of hand.
--------
Furthermore, Keith Kidder (Hi, Keith) gave me an idea when he suggested that the Vifa M series drivers were a poor man's scanspeak.
If you try modelling the drivers, dual M18s, P13 and XT 25, they could be made to perform (and look
) like a poor man's Sonus Faber Cremona quasi-clone. Not quite the bang but nowhere near the buck.Anyone?
Mos
Mos,
I like these Vifas. Half the cost of th 8545 Scanspeak, and maybe 90% of the quality. I don't see them as a poor man's Scanspeak; rather, I see the Scanspeak as a cynically marketed speaker for the DIY perfectionist.......
Yes, these drivers will do fine crossed over low, BUT, they are also a midrange speaker, up to 2,500Hz is just fine, and I see this as a waste.
I prefer to use two ways, and augment with a sub. I feel this has less damaging effect on the music in that essential 200Hz-3KHz range where most of the imaging is found. A three way uses a band pass filter and their effect on phase is horrific.
Cheers,
Hugh
I like these Vifas. Half the cost of th 8545 Scanspeak, and maybe 90% of the quality. I don't see them as a poor man's Scanspeak; rather, I see the Scanspeak as a cynically marketed speaker for the DIY perfectionist.......
Yes, these drivers will do fine crossed over low, BUT, they are also a midrange speaker, up to 2,500Hz is just fine, and I see this as a waste.
I prefer to use two ways, and augment with a sub. I feel this has less damaging effect on the music in that essential 200Hz-3KHz range where most of the imaging is found. A three way uses a band pass filter and their effect on phase is horrific.
Cheers,
Hugh
Mos Fetish said:
Pardon me if I can't stand to express my believes. I have been keeping this for myself just because I found no experts have the same belief...
No software can quantify all what your hearing can. Anything that you assume "good result" from the LspCad output doesn't necessarily have high correlation with anything good to your hearing.
You can cross M18 at 250Hz and you can cross it at 1KHz. In both cases you may have a flat response around 80Hz. But these 80Hz will have different quality to your hearing!
Good sounding speaker came from good sounding LP band AND good sounding HP band. And it's not just about where you should cross your driver.
As michael suggested, I'm afraid an LP band from M18 crossed at 250Hz will never be better than an LP band from anything 10" crossed at the same frequency.
Every driver have somekind of "best filter". You can incorporate certain drivers with their "best filters" to make up a speaker. But this is not always possible. Often one driver must be operated a bit outside it's "best filter" to make up a working speaker, as dictated by formulas and graphs.
To have a speaker which have drivers operating at their "best filter", we have to select a "matched" Woofer-Tweeter, W-M-T, W-W-M-T and so on. The more cross-points, the more difficult to find this match. My intuition is you cannot have better speaker out of M18+P13+XT25 than what you can have out of M18+XT25 or M18+D75+XT25 (as also suggested by michael) or even P13+XT25+subwoofer.
"This is an exceptionally good combination, with gorgeous imaging, unbelievable detail and wonderful engagement [AKSA]". I can imagine that from M18 and XT25 drivers, especially if they can work together at their "best filters" with simple series crossover. A "best filter" is marked with the placement of sounds (and singer) in space. You don't hear any sound coming from your drivers' cones.
I prefer to have my drivers working at their "best filter" with a few problems here and there than to have a smooth speaker who cannot make me fly (is this the same word for "wonderful engagement"?).
Thank's Mos, for not saying this is a stupid opinion
I'll just add you'll need two M18's in this application wired in
parallel.
Due to the ' baffle step' effect the bass unit must have
~ 6dB more IEC baffle sensitivity than the midrange and
treble drivers. Way to do this is use two in parallel.
Some of the arguements below are simply ignoring this fact.
In a 2 way the 6dB baffle step is corrected by the crossover
giving you fairly low sensistivity through midrange and treble.
The 3 way with two M18's will be ~ 6dB more sensitive and you
wont have to pad the midrange and treble drivers to death.
But note it will require double the bass enclosure volume.
And be half the impedance (4ohm vs. 8ohm).
Arranging the bass / midrange crossover is complicated by the
baffle step occurring around this frequency - probably the cause
of many 3 ways not integrating bass and midrange well.
/sreten
parallel.
Due to the ' baffle step' effect the bass unit must have
~ 6dB more IEC baffle sensitivity than the midrange and
treble drivers. Way to do this is use two in parallel.
Some of the arguements below are simply ignoring this fact.
In a 2 way the 6dB baffle step is corrected by the crossover
giving you fairly low sensistivity through midrange and treble.
The 3 way with two M18's will be ~ 6dB more sensitive and you
wont have to pad the midrange and treble drivers to death.
But note it will require double the bass enclosure volume.
And be half the impedance (4ohm vs. 8ohm).
Arranging the bass / midrange crossover is complicated by the
baffle step occurring around this frequency - probably the cause
of many 3 ways not integrating bass and midrange well.
/sreten
Bricolo,
I think the answers given so far suffice; speaker building is highly subjective, the artful management of compromise.
We use 3rd order filters because we find they sound the best overall. I will not disagree with sreten; he knows his stuff. But this is an art, many things are done seemingly without explanation, and this is the reason many design decisions come from left field, without apparent explanation. The final outcome is determined, as our friend from Jakarta has said, by what is heard.
For reasons of protecting IP I'm not willing to discuss each and every design point of my products in a public forum; the industry is extremely competitive and one must keep a few secrets.
I hope you understand - there are no categoric statements!
Cheers,
Hugh
I think the answers given so far suffice; speaker building is highly subjective, the artful management of compromise.
We use 3rd order filters because we find they sound the best overall. I will not disagree with sreten; he knows his stuff. But this is an art, many things are done seemingly without explanation, and this is the reason many design decisions come from left field, without apparent explanation. The final outcome is determined, as our friend from Jakarta has said, by what is heard.
For reasons of protecting IP I'm not willing to discuss each and every design point of my products in a public forum; the industry is extremely competitive and one must keep a few secrets.
I hope you understand - there are no categoric statements!
Cheers,
Hugh
Thanks AKSA - nice to know someone thinks ' I know my stuff' !
I'll just note the point of the the 3 way with 2 M18's
would be the higher sensistivity, and the two bass
units will allow a more extended bass alignment before
you run into excursion limitations in the low bass.
I'll also note that 55 litres is a silly volume for a driver
with Vas = 29 litres IMO. IMO 45 to 55 litres is about
right for two M18's with the port tuned to ~ 30Hz for
an overdamped extended bass alignment that should
match real rooms fairly well.
The port can be tuned higher for more power handling
and a less lean bass, but its not what I would do.
/sreten.
I'll just note the point of the the 3 way with 2 M18's
would be the higher sensistivity, and the two bass
units will allow a more extended bass alignment before
you run into excursion limitations in the low bass.
I'll also note that 55 litres is a silly volume for a driver
with Vas = 29 litres IMO. IMO 45 to 55 litres is about
right for two M18's with the port tuned to ~ 30Hz for
an overdamped extended bass alignment that should
match real rooms fairly well.
The port can be tuned higher for more power handling
and a less lean bass, but its not what I would do.
/sreten.A short posting with a page of what I think you have to read before you start buying anything:
http://www.linkwitzlab.com/mid_dist.htm
The Vifa isn't really THAT good (just like the ScanSpeak)....
If you have a low crossover frequency for the crossover, you could also take a look at the new Visaton TIW200XS (is pretty cheap for what it can do!)
With this unit you'll get: FS=28Hz, a LOW Rms, Mms of 33g (FAST)... with a pretty flat response until 1000Hz (above that the resonance at about 4kHz starts to grow in annoyance).
http://www.visaton.de/cgi/VisatonFramed.asp?Artikel_ID=768&Sprache=english
As you can see, it isn't ugly at all I can find only one drawback (is that the right word?) : is has an efficiency of 84 dB/1W/1m.
Just for your information.
Grtz, Joris
http://www.linkwitzlab.com/mid_dist.htm
The Vifa isn't really THAT good (just like the ScanSpeak)....
If you have a low crossover frequency for the crossover, you could also take a look at the new Visaton TIW200XS (is pretty cheap for what it can do!)
With this unit you'll get: FS=28Hz, a LOW Rms, Mms of 33g (FAST)... with a pretty flat response until 1000Hz (above that the resonance at about 4kHz starts to grow in annoyance).
http://www.visaton.de/cgi/VisatonFramed.asp?Artikel_ID=768&Sprache=english
As you can see, it isn't ugly at all
I can find only one drawback (is that the right word?) : is has an efficiency of 84 dB/1W/1m. Just for your information.
Grtz, Joris
Hi joris >>>
midrange performance is irrelevant for a bass unit in 3 way.
Your Visaton unit has at least two 'drawbacks' which is the right word.
1. low sensitivity - which you pointed out
2. Vas at 60 L is twice the M18 at 29 L, with similar Q's the
Visaton will require ~ twice the enclosure volume of the M18.
What do you get in return ? Excursion capability.
Its all a question of compromises and IMO the M18 is a very
good unit for compact quality speakers.
The Visaton IMO is not optimised for compact speakers.
/sreten.
midrange performance is irrelevant for a bass unit in 3 way.
Your Visaton unit has at least two 'drawbacks' which is the right word
.1. low sensitivity - which you pointed out
2. Vas at 60 L is twice the M18 at 29 L, with similar Q's the
Visaton will require ~ twice the enclosure volume of the M18.
What do you get in return ? Excursion capability.
Its all a question of compromises and IMO the M18 is a very
good unit for compact quality speakers.
The Visaton IMO is not optimised for compact speakers.
/sreten.Thanks for all your replies.
I made it clear early on that this design was intended to have 2 x M18s, so 55 litres is a good vb for a mid-30s f3. Room gain shows a slight lowering of the f3 with quite a low boost overall.
Personally, I like the idea of taking a driver like the M18 that has tuneful bass and then allowing it to handle that bass exclusively while handing the midrange off to something else like the P13.
Does anyone classify a 3 way with 2 x M18, P13 and XT25 as a "small" 3 way? I think it would have plenty of powerhandling, extension and would be all you would need for an average sized room (mine is 8x4x2.3 meters).
Mos
I made it clear early on that this design was intended to have 2 x M18s, so 55 litres is a good vb for a mid-30s f3. Room gain shows a slight lowering of the f3 with quite a low boost overall.
Personally, I like the idea of taking a driver like the M18 that has tuneful bass and then allowing it to handle that bass exclusively while handing the midrange off to something else like the P13.
Does anyone classify a 3 way with 2 x M18, P13 and XT25 as a "small" 3 way? I think it would have plenty of powerhandling, extension and would be all you would need for an average sized room (mine is 8x4x2.3 meters).
Mos
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