Personal taste question: how much air/Q would you give the 12mu/4731T00 in an sealed enclosure ?
0.707/0.577/0.5 or below ?
0.707/0.577/0.5 or below ?
alignments are more then just for pushing the frequency up. vance dickason, loudspeaker cookbook, otc in sealed boxes.(was it neville or thiele who did the physics ? i can't remember)
i asked for the personal taste to people who used this driver. cause aligments have an impact of the sound.
a simple question. simple answer.
Ok, I just wanted to point out that your question was like ‘what glass do you prefer for your aperitif?’ Too general.
As a side remark: Qtc is not that important or audible, certainly not if you use an electric band pass filter that has no real interaction with the electroacoustic highpass of the driver in the enclosure as in aiming for a predefined Q and order of the combination of filters. Such mids often are crossed around 500Hz or higher, while fc is mostly around 100Hz. As in: ‘you don’t use the thing in the resonant frequency domain, why bother about Q?’ And it’s likely other effects like lower resonance frequencies from bigger cavities behind the driver play a more important role.
As a side remark: Qtc is not that important or audible, certainly not if you use an electric band pass filter that has no real interaction with the electroacoustic highpass of the driver in the enclosure as in aiming for a predefined Q and order of the combination of filters. Such mids often are crossed around 500Hz or higher, while fc is mostly around 100Hz. As in: ‘you don’t use the thing in the resonant frequency domain, why bother about Q?’ And it’s likely other effects like lower resonance frequencies from bigger cavities behind the driver play a more important role.
@markbakk
eg. see transient response, fig. 6 step response (especially for those who can only "hear" with there eyes 😉 )
https://sdlabo.jp/archives/Closed_Box_Loudspeaker_Systems_Part_1-2.pdf
even friends with "untrained ears" and which no hifi hobbists where immediately able to tell there is a difference and what kind of. (in their words)
so "Qtc is not that important or audible"
maybe its unknown while never experienced, but not audible is a myth
and maybe.... this knowledge is to old and forgotten.
eg. see transient response, fig. 6 step response (especially for those who can only "hear" with there eyes 😉 )
https://sdlabo.jp/archives/Closed_Box_Loudspeaker_Systems_Part_1-2.pdf
even friends with "untrained ears" and which no hifi hobbists where immediately able to tell there is a difference and what kind of. (in their words)
so "Qtc is not that important or audible"
maybe its unknown while never experienced, but not audible is a myth
and maybe.... this knowledge is to old and forgotten.
My experience is that it was audible.
A Q up to 1 is used to get this little exta bassy sound in many small speakers.
Going to 0.7 it is much less pronounced, going to about 0.5 to 0.6 it needs some correction of the output loss ref 0.7 but it sounded clean.
This was with stuffed sealed boxes and close listening and in large space to avoid room modes.
I know the Richard Small paper very wel as at that time i redid the tests .
Having said this in normal use, like in my living room and at longer listening distances the room modes are more pronounced and a concern requiring attention to control these.
A Q up to 1 is used to get this little exta bassy sound in many small speakers.
Going to 0.7 it is much less pronounced, going to about 0.5 to 0.6 it needs some correction of the output loss ref 0.7 but it sounded clean.
This was with stuffed sealed boxes and close listening and in large space to avoid room modes.
I know the Richard Small paper very wel as at that time i redid the tests .
Having said this in normal use, like in my living room and at longer listening distances the room modes are more pronounced and a concern requiring attention to control these.
Sometimes a simple question doesn't necessarily mean a simple answer.
The Q matters in a woofer as it determines the cut off and shape. Are you using the 12MU as a woofer or as a midrange?
As a woofer after selecting the theoretical Q, you also need to take into account baffle step losses. A response around 0.707 at 2pi (near field, anechoic) may actually be close to 0.6 in the free field (4pi), depending on your baffle shape/dimensions. But even a "nice" Q of 0.5 in the free field may go all over the place in-room, at the listening position.
As a midrange, if you're playing it FULL range ie. without a high pass filter, then you need to care about your Q.
If you're using your HP filter on your midrange eg. Fc 300Hz, then it doesn't really matter- your HP filter will determines the cut off and shape.
If this is the case, just put in as large/deep a cabinet that you can tolerate eg. 2-4L, and deaden/dampen it...
So it depends...
The Q matters in a woofer as it determines the cut off and shape. Are you using the 12MU as a woofer or as a midrange?
As a woofer after selecting the theoretical Q, you also need to take into account baffle step losses. A response around 0.707 at 2pi (near field, anechoic) may actually be close to 0.6 in the free field (4pi), depending on your baffle shape/dimensions. But even a "nice" Q of 0.5 in the free field may go all over the place in-room, at the listening position.
As a midrange, if you're playing it FULL range ie. without a high pass filter, then you need to care about your Q.
If you're using your HP filter on your midrange eg. Fc 300Hz, then it doesn't really matter- your HP filter will determines the cut off and shape.
If this is the case, just put in as large/deep a cabinet that you can tolerate eg. 2-4L, and deaden/dampen it...
So it depends...
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Did you (or anyone) do this test with midranges that were bandpass filtered? Do you know the (highpass) filter changes the system Q? I was not talking about units that are running full range.