Haunz
10+ year member
Packing 4/0
I think immacomputer's first post is what everyone should pay attention to.. transient/impulse response will depend on QTS of the system which is a function of all the woofer's T/S paramaters and the enclosure as well as the electrical inductance of the system..
Not at all.. I think the test was valid.. and shows how the raw driver (which is a mid) responds naturally, and with added inductance or added mass..
I haven't read the whole paper but at first glance you can see in the first two graphs how the impulse response is improved with the added mass (as the added mass lowers the drivers Q)... while the added inductance hinders the driver's impulse response.. you can also see how adding inductance delays the driver's response...
I think these graphs spell out transient/impulse response, what it is, and what affects it quite well..
so what is the question? it almost seems that all of the analysis thus far only goes so far as to prove inductance and mass are not limiting factors.
look at the OP's PDF link. the timescale is on the order of 5ms, with visually identifiable events within a fraction of a millisecond. pretty much all of that is stuff that is well above 200hz. the main parts are closer to 2khz it would seem.
This calls into question the validity of the testing -- after all, for car audio someone will be using most likely a 4th order (-24dB/oct) lowpass below 2000hz and even below 200hz. when this is added to the response the "transient" response would likely look almost like a flat line. in the 5ms timescale the filter would largely reject the impulse, except for the lower frequency components, which would not appear "transient" on the 5ms timescale.
further, the zoomed in picture shows a delay difference of what seems to be 1 sample, or 21us. this would be similar to having the woofers located a massive 1/4 to 1/2" further away from you then the rest of the speakers. its likely your time correction features won't even be able to correct for such a small difference.
Not at all.. I think the test was valid.. and shows how the raw driver (which is a mid) responds naturally, and with added inductance or added mass..
I haven't read the whole paper but at first glance you can see in the first two graphs how the impulse response is improved with the added mass (as the added mass lowers the drivers Q)... while the added inductance hinders the driver's impulse response.. you can also see how adding inductance delays the driver's response...
I think these graphs spell out transient/impulse response, what it is, and what affects it quite well..