Originally Posted by kaiforce
I used the params for the V2 unit posted on SI's site. Are these incorrect?
It looks like you enter your parameters in Qes and Qts(since they are green) so we have different values. I use the way the WINISD help file says to enter them and WINISD auto calculates Qes and Qts as you can see mine are blue. But they are close enough I dont think it would make a 3dB difference in output.
I tried entering your parameters to compare them and WINISD gives me an error for them, I will attach it below.
Also, you said "4 sealed si HT18's is the black line. (1200 watts per box, no HPF)
2 dayton HO 18's in stonehenge boxes is the red line (900 watts per box, HPF @ 20hz)"
I took it you meant 2400watts total for the 4 sealed? That would be 600 per box/enclosure, that is what I used is 2400watt/600 per driver. Maybe you used 1200w total which would make sense how your numbers are 3-4dB less than mine for the sealed SI's. I think this is why we have the difference in numbers.
From WINISD help file.
"The suggested procedure for entering driver parameters is following (check first that "Auto calculate unknowns" option is checked):
1. Enter Mms and Cms
This gives fs. If either is not available, then enter fs and other parameter.
2. Enter Sd, Bl and Re
Now, you should get all but Qms (and Qts), Vas. Please note that Vas may not match exactly what is specified by manufacturer, because exact value of Vas depends on environmental parameters. See FAQ.
3. Enter Rms or Qms.
Either one will do, although I tend to prefer Qms over Rms, because it can usually be measured in driver measurement procedures.
4. Enter Hc, Hg and Pe.
If Hc or Hg or either is available, then enter Xmax and optionally either Hc or Hg if available.
5. Enter number of voicecoils.
This procedure is most accurate. Also note that it also calculates true SPL (1W/1m) value. So it might not match the marketing SPL value, which is generally somewhat vague. Not in all cases, though.
6. Correct Znom, if necessary.
If there are several voicecoils, then you must be careful when entering parameters in that case, because many manufacturers give Bl in voice coils in series, because it yields double value for Bl against parallel connection. If driver manufacturer gives Qes, Bl and Cms or Mms, then you can check how Bl is specified. For that, you can enter following parameters to calculate Re: Qes, Fs, Mms or Cms and Bl. Connection mode can be changed by changing the combobox selection. The driver editor then converts Bl and Re values accordingly.
Equivalently, you can check for Bl by entering:
Qes, Fs, Mms or Cms and Re (for desired connection mode).
If you enter resistance for parallel connection and get about half of advertised Bl, then you know, that Bl was specified that way."