Hi,
I am assuming that fullrange drivers like Visaton BG20 with whizzers dont provide uniform polars. A whizzer ends up producing highs mostly on axis at the expense of spoiling the off axis response. This is an acoustic problem so cant be solved by EQ either.
Drivers like TC9 etc have a dustcap and their on axis and off axis response are uniform.
See 4&5 for visaton TC9(dustcap) and Visaton (whizzer) comparison below
Radiation patterns of full range drivers
Can whizzers be improved to yield better polars?
Does replacing whizzer with dustcap improve the polars?
Thanks and Regards,
WA
I am assuming that fullrange drivers like Visaton BG20 with whizzers dont provide uniform polars. A whizzer ends up producing highs mostly on axis at the expense of spoiling the off axis response. This is an acoustic problem so cant be solved by EQ either.
Drivers like TC9 etc have a dustcap and their on axis and off axis response are uniform.
See 4&5 for visaton TC9(dustcap) and Visaton (whizzer) comparison below
Radiation patterns of full range drivers
Can whizzers be improved to yield better polars?
Does replacing whizzer with dustcap improve the polars?
Thanks and Regards,
WA
Unfortunately there is no guarantee that a drive unit without additional sub-cones will 'provide uniform polars'.
Off-axis response is heavily dependent on cone geometry / profile, central pole-piece covering / termination and the nature of the surround and basket design. Additional sub-cones are most often (although not exclusively) employed in larger drive units. The most common reasons for their use are
a/ The main cone or an alternative sub-emitter (e.g. central cap) alone cannot produce sufficient HF extension, and
b/ To increase HF outout, ironically enough, for off-axis listeners since the size and geometry of the main cone may result in excessive HF directionality if (if) an alternative method of producing sufficient HF extension (such as a central cap coupled to the VC, ) were used.
The comparison is at best flawed, but if you wish to compare on / off axis responses, I suggest you at least try to do so between drivers of the same size i.e. total surface emitting area (Sd). As noted, even then it's problematical as the drivers are unlikely to be of the same basic design (cone profile / geometry, surround & edge termination etc.).
Off-axis response is heavily dependent on cone geometry / profile, central pole-piece covering / termination and the nature of the surround and basket design. Additional sub-cones are most often (although not exclusively) employed in larger drive units. The most common reasons for their use are
a/ The main cone or an alternative sub-emitter (e.g. central cap) alone cannot produce sufficient HF extension, and
b/ To increase HF outout, ironically enough, for off-axis listeners since the size and geometry of the main cone may result in excessive HF directionality if (if) an alternative method of producing sufficient HF extension (such as a central cap coupled to the VC, ) were used.
The comparison is at best flawed, but if you wish to compare on / off axis responses, I suggest you at least try to do so between drivers of the same size i.e. total surface emitting area (Sd). As noted, even then it's problematical as the drivers are unlikely to be of the same basic design (cone profile / geometry, surround & edge termination etc.).
"Drivers like TC9 etc have a dustcap and their on axis and off axis response are uniform."
really? it beams like laser
have you seen the of axis response?
really? it beams like laser
have you seen the of axis response?
If you see the link I posted, tc9 is best amongst others. Beaming is a loose term. If you mean 'beaming' to be narrow directivity then all waveguides beam. I am after uniform narrow directivity.
A TC9 is a 3” driver, there is little reason for a whizzer on anything smaller than 6.5”. Dispersion is a function of come size (and a whole bunch of other things).
dave
dave