impedance is fairly flat from 20 - 80Hz, at about 2.5ohm, with a single peak at about 28Hz...
and the impedance decreases under 20Hz down to 1ohm at 10Hz... from memory...
it was designed to use the car as part of the box, to act as a tapped horn, so the drivers are then the same distance from the back wave to the front wave
impedance is fairly flat from 20 - 80Hz, at about 2.5ohm, with a single peak at about 28Hz...
and the impedance decreases under 20Hz down to 1ohm at 10Hz... from memory...
it was designed to use the car as part of the box, to act as a tapped horn, so the drivers are then the same distance from the back wave to the front wave
this is in the car the impedance measurements were made, because its intended to be used in the car
issue is, that the dayton woofer tester will give fairly varying results.
just been playing around with the dayton woofer tester again.
measuring "t/s specs" with the drivers in the box, and in the car.
generally the WT will report an FS of around 24Hz, but sometimes (1 out of 5 maybe?) it will claim an FS of 50+hz.
I'll post some photos of the impedance plots, most have been changed to only display 10 - 100Hz, and 15ohm maximum impedance, while others show the full frequency range...
pics to come! I'll let you all decide if its a transmission line, or a high tuned box...
measuring "t/s specs" with the drivers in the box, and in the car.
generally the WT will report an FS of around 24Hz, but sometimes (1 out of 5 maybe?) it will claim an FS of 50+hz.
I'll post some photos of the impedance plots, most have been changed to only display 10 - 100Hz, and 15ohm maximum impedance, while others show the full frequency range...
pics to come! I'll let you all decide if its a transmission line, or a high tuned box...
my mistake... 1Hz - 100Hz
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
my mistake... 1Hz - 100Hz
Something's not right there. If the WT3 is not giving consistent results, then you need to investigate why and fix it. For example, remove any possible external factors that might be interfering with the measurements (e.g. take the measurements with all windows up, the car off and the subwoofer disconnected from the amplifier).
You should have gotten some ground plane measurements just to see how it stacks up to other subwoofers on this forum (I know I know it was designed to be used IN the car, but still woulda been neat)
Old thread I know, but for what it's worth, one cannot measure T/S parameters since the speakers are in an enclosure. The reason the specs come in differently is not because of cone area as had been suggested, it is because there are two main impedance minimums, which then causes several impedance peaks which is what the WT3 looks for when calculating T/S parameters; but with two peaks it is surely getting confused and doesn't know which one to "hone in" on because a free-air (or baffled) speaker only has one impedance peak from which to extract T/S parameters.
Really? I thought WT3 was supposed to be able to measure this too. You'd use it within those circumstances when adjusting an AP membrane to achieve the tuning you want- I haven't done this myself yet, but know of others who have.
The intent was to use the WT3 to measure the impedance response, not the t/s parameters.
Measure what, impedance? Of course, one of it's main functions is to generate an impedance curve that can be a tool for tuning an enclosure. I wasn't attempting to debate that, simply stating that the WT3 cannot "look" for parameters while a speaker is installed in an enclosure.
..then perhaps I misunderstood your reply to that post. I know you know your stuff
they're sitting in the basement (aka, "rape dungeon")
I have 18 of them now, one the rubber gasket on the front is completely unglued
and nearly all of them are starting to de-laminate, so the yellow "kevlar" is separating from the cone surface
they didn't last long...
however, I still plan to make some tapped horns for them, probably when I'm not living in my parents house...
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.