Well,recently i revised a old 3-way construction i build in the early
eighties if im remembering correctly. The speaker used were
MHD24TDSM and MHD12FSM-AC from Audax and the first MCD-25
titan-dome tweeter from MB.
It was a rather big box i have to admit,around 65 liters netto for the
bass alone and the crossover network was 18dB/Oct. with some
additional filtering for impedance and level correction.
However,it was a good sounding one with good SPL and power
handling and i build it a couple times for friends and friends of friends.
Well,anyway,more to the point,while the bass is still in production and
the tweeter can easily be replaced by another good one (there is a
buckload of really good 1 inch tweeters out there meanwhile),im having
a hard time to find a replacement for the MHD12FSM-AC.
But probably im seeing the wood not for the trees here. Im looking for
a 4 inch mid with 92dB/W/m and linear response roughly from 400 to
4000 Hz. Help please.
eighties if im remembering correctly. The speaker used were
MHD24TDSM and MHD12FSM-AC from Audax and the first MCD-25
titan-dome tweeter from MB.
It was a rather big box i have to admit,around 65 liters netto for the
bass alone and the crossover network was 18dB/Oct. with some
additional filtering for impedance and level correction.
However,it was a good sounding one with good SPL and power
handling and i build it a couple times for friends and friends of friends.
Well,anyway,more to the point,while the bass is still in production and
the tweeter can easily be replaced by another good one (there is a
buckload of really good 1 inch tweeters out there meanwhile),im having
a hard time to find a replacement for the MHD12FSM-AC.
But probably im seeing the wood not for the trees here. Im looking for
a 4 inch mid with 92dB/W/m and linear response roughly from 400 to
4000 Hz. Help please.
Friedell, If you did a Google search and visited the Audax website you would know that no standard Audax MHD12FSM exists. BAD MEMORY? Wrong number? Custom order number? Pull the speaker and check.
Unless you want to design a completely new crossover, you will need to purchase an EXACT match to your "MHD12FSM-AC". So.... you will need to measure the T/S parameters of the remaining good MHD12FSM and search for a replacement. If the price is modest, you may want to replace both.
Measuring Thiele / Small Loudspeaker Parameters
Measuring Loudspeaker Driver Parameters
I'm currently using this 4" Tangband (Tang Band W4-656SC 4" Shielded Driver) in a quasi-fulrange alignment, high pass @ 100Hz and full range at the top, and it works pretty well.
There are also many threads and posts you could search here that may be helpful, here's one I found that might be of interest, http://www.diyaudio.com/forums/full-range/270614-subjective-blind-comparison-3in-5in-full-range-drivers.html.
Mike
There are also many threads and posts you could search here that may be helpful, here's one I found that might be of interest, http://www.diyaudio.com/forums/full-range/270614-subjective-blind-comparison-3in-5in-full-range-drivers.html.
Mike
This driver might complement your loudspeaker.
http://www.scan-speak.dk/datasheet/pdf/10f-4424g00.pdf
Regarding SPL, 94 dB is too much to ask for because your woofer is no
more than 89-90 dB in open space and the midrange driver is getting spl
boost being band passed anyway. There is the SS 12 MU 4731 T00 as well.
The midrange is probably MHD 12 P 25 FSM. As Linesource tells you, a new filter have to be made if you don't find a midrange that exactly matches the Audax on the electrical and acoustical parameters. An alternative could be to get the old ones restored like here Proraum Vertriebs-GmbH | AUDAX MHD12P25 Reparatur/Reconing or here Lautsprecherreparaturen.
If it is only the surround that needs refurbishment, maybe this one can be something for you Audax MHD 12 P25 FSM Hoch Mittelton Sicken Kit 2 x 96 | eBay
A third option would be to buy second hand drivers Hp audax mhd 12 25 fsm Image & Son Indre-et-Loire - leboncoin.fr
If it is only the surround that needs refurbishment, maybe this one can be something for you Audax MHD 12 P25 FSM Hoch Mittelton Sicken Kit 2 x 96 | eBay
A third option would be to buy second hand drivers Hp audax mhd 12 25 fsm Image & Son Indre-et-Loire - leboncoin.fr
The midrange is a MHD12P25FSM-AC. Its basicly a MHD12 but the membrane
is coated with acronal -hence "AC"- and the surrounding is,well was, flat,not arched
like the ones available for refurbishing. If i use that the Cms goes way up and the
whole tuning south.
Anyway,thanks for the feedback.
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