He always measures. Measurements of t/s are here - Data-Bass
He also measured the driver in the 4.5 cu ft sealed box so check the measurements of that too. It measured more like a pro driver in response shape (which is very very good) but with more low end output than any of the 18 inch heavy hitters.
It's a nice driver with a lot of state of the art features but it sure does cost a lot.
@ just a guy
Thanx for the DB link
Even with the T/S from there, i'm still getting an error with the computed data in WinISD v07.0.900 ? This happens rarely in my long experience with it, & only when one or more of the entered specs are incorrect, due to one or more incorrect published T/S specs.
TS Parameter (Measured by Data-Bass.com) Res = 1.7 Ohms - If this is supposed to mean the DC resistance Re ? then it's over 3.5 times the stated 0.45 Ohms in the vendors link !
Now, i'm Not knocking Rikki's design etc, just trying to establish what's what, as something isn't right !
Thanx for the DB link
Even with the T/S from there, i'm still getting an error with the computed data in WinISD v07.0.900 ? This happens rarely in my long experience with it, & only when one or more of the entered specs are incorrect, due to one or more incorrect published T/S specs.
TS Parameter (Measured by Data-Bass.com) Res = 1.7 Ohms - If this is supposed to mean the DC resistance Re ? then it's over 3.5 times the stated 0.45 Ohms in the vendors link !
Now, i'm Not knocking Rikki's design etc, just trying to establish what's what, as something isn't right !
Attachments
Chances are there's a problem with rounding errors. WinISD will throw a hissy fit unless you let it calculate to the nth decimal place.
I'd recommend entering Mms, Fs, Qes, Qts, Sd, Re, Le, and any large-signal parameters you think might be relevant. IIRC, it can calculate the rest from those.
I'd recommend entering Mms, Fs, Qes, Qts, Sd, Re, Le, and any large-signal parameters you think might be relevant. IIRC, it can calculate the rest from those.
Perhaps you were looking at the datasheet for the 1 ohm version (T3S1-19), not the 2 ohm version that was tested (T3S2-19)
Hmmmm....actually the only "0.45" number is for the Le, which is one line below Re.
T3S1-19 - Power 19" T3 Single 1-Ohm Superwoofer | Rockford Fosgate®
T3S2-19 - Power 19" T3 Single 2-Ohm Superwoofer | Rockford Fosgate®
I compared the ammended T/S with WinISD and Horn Response, and virtually got the same auto calculated results.
Maybe the earlier versions did, but the later ones are fine. I know how to use it, i even made a thread about it http://www.diyaudio.com/forums/subwoofers/148729-how-correctly-use-winisd.html
Yes thanx, you're right i was initially. Even after entering the tested specs for the 2 ohm i still get the error alert. However, i can still successfully sim any number of designs regardless.
My mistake, so thanx for pointing it out. I did enter the correct figure when simming though, and i've redone it to make sure.
Maybe the earlier versions did, but the later ones are fine. I know how to use it, i even made a thread about it http://www.diyaudio.com/forums/subwoofers/148729-how-correctly-use-winisd.html
)
Yes thanx, you're right i was initially. Even after entering the tested specs for the 2 ohm i still get the error alert. However, i can still successfully sim any number of designs regardless.
My mistake, so thanx for pointing it out. I did enter the correct figure when simming though, and i've redone it to make sure.
I guessed right. It's just a ported slot loaded box, nothing at all like a horn. Basically a simple 6th order bandpass. The port looks a bit small for 4 of those drivers but he did mention he was getting a bit of port noise. The box is so tiny a larger port wouldn't have fit, compromises need to be made.
I'm wondering why he didn't make it a series-tuned design. That should allow for a larger port in the same total volume.
Indeed. A 12" diameter vent is about the limit of what would fit. It is cram packed on the inside. I wish I could have used a full 60x60" form. The extra volume and space to adjust some things would have been welcome. Unfortunately I just could not fit something that big.
It wouldn't have worked well for this design. No room inside the cab for starters.
I never had any issue with the provided factory parameters for the drivers or the ones I have pulled. Everything adds up just fine.
Care to post your specs that you are entering?
@ Josh Ricci
Hi, i used the same T/S as you did, & after my initial concerns etc, i redid the sim as before & got the same results. I wasn't complaining at all, just wondered why the error appeared. It didn't make any difference to the results.
Once again, Thanx for a Very informative & nicely laid out & tidy www What does ZOD mean ?
Regards
Hi, i used the same T/S as you did, & after my initial concerns etc, i redid the sim as before & got the same results. I wasn't complaining at all, just wondered why the error appeared. It didn't make any difference to the results.
Once again, Thanx for a Very informative & nicely laid out & tidy www
What does ZOD mean ?Regards
@ Josh Ricci
Hi, i used the same T/S as you did, & after my initial concerns etc, i redid the sim as before & got the same results. I wasn't complaining at all, just wondered why the error appeared. It didn't make any difference to the results.
Once again, Thanx for a Very informative & nicely laid out & tidy www
Regards
Only the greatest Superman movie ever!!
https://www.youtube.com/watch?v=UKDFop0aqYQ
@ Josh Ricci
Hi, i used the same T/S as you did, & after my initial concerns etc, i redid the sim as before & got the same results. I wasn't complaining at all, just wondered why the error appeared. It didn't make any difference to the results.
Once again, Thanx for a Very informative & nicely laid out & tidy www
Regards
Hmmm. No idea. No errors on my copy of winisd. Only thing I even use that for is holding driver parameters anymore. I'm not even sure if it's up to date.
Thanks for the encouragement.
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