I don't think Vifa reccomend a sealed enclosure. I haven't ever tried modeling a sealed enclosure for it. I have these woofers in my 3 way, vented about 70L currently (I think), can't remember the tuning freq, I've lost all my design documentation 
I think I came up with about 75L vented as a good compromise between size and bass extention for when I redo the cabinets, simulated an f3 of about 36Hz from memory, although I really would like to do better than that, especially since the resonant freq of the woofer is around 28Hz.....
Tony.
edit: Well I went looking for the official vifa spec sheet (I've got a printout somewhere, but it used to be on the web). Didn't find it but did find this: http://users.tpg.com.au/gadget69/M26WR-09-08.jpg Which says suitable for vented or sealed enclosure, so I guess get the modelling prog out and try some stuff out
I think I came up with about 75L vented as a good compromise between size and bass extention for when I redo the cabinets, simulated an f3 of about 36Hz from memory, although I really would like to do better than that, especially since the resonant freq of the woofer is around 28Hz.....
Tony.
edit: Well I went looking for the official vifa spec sheet (I've got a printout somewhere, but it used to be on the web). Didn't find it but did find this: http://users.tpg.com.au/gadget69/M26WR-09-08.jpg Which says suitable for vented or sealed enclosure, so I guess get the modelling prog out and try some stuff out
P.S. The above plot was done with winISD, which is free :
http://www.linearteam.dk/default.aspx?pageid=winisd
there are three different 10"M26WR's in the database.
sreten.
http://www.linearteam.dk/default.aspx?pageid=winisd
there are three different 10"M26WR's in the database.
sreten.
Heres a couple done with unibox
Note that the T/S params are the ones I measured myself (found the printout yay).... The only significant difference to the published specs was the resonant freq which I measured at 29Hz. (using added mass method with a scale acurate to 0.1g)
Note that the sealed graph was optomised for a Qtc of 0.5
Also note that while the vented graph shows 1db response peak its actually .5db rounded up. Further note that the falling off of response after 200 Hz I would say is an acurate model, as the measurements I did recently with speaker workshop show exactly the same behaviour (only in a 70L vented box) in the real world finished item. Modeling done with a series resistance of 0.5 ohm.
Modelling done with Unixbox (also free) for which the main drawback is you need microsoft excell to use it.
If you would like to see the step response I'll post the comaprison graph from unibox...... I can see why people opt for sealed alignments looking at it!
had to truncate the graphs as resising them completely wrecked the fonts.
Tony.
edit: BTW my T/S params are:
Fs 29.2
Vas 125L
Qms 2.79
Qes .368
Le 1.79
Note that the T/S params are the ones I measured myself (found the printout yay).... The only significant difference to the published specs was the resonant freq which I measured at 29Hz. (using added mass method with a scale acurate to 0.1g)
Note that the sealed graph was optomised for a Qtc of 0.5
Also note that while the vented graph shows 1db response peak its actually .5db rounded up. Further note that the falling off of response after 200 Hz I would say is an acurate model, as the measurements I did recently with speaker workshop show exactly the same behaviour (only in a 70L vented box) in the real world finished item. Modeling done with a series resistance of 0.5 ohm.
Modelling done with Unixbox (also free) for which the main drawback is you need microsoft excell to use it.
If you would like to see the step response I'll post the comaprison graph from unibox...... I can see why people opt for sealed alignments looking at it!
had to truncate the graphs as resising them completely wrecked the fonts.
Tony.
edit: BTW my T/S params are:
Fs 29.2
Vas 125L
Qms 2.79
Qes .368
Le 1.79
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