Ported Alignments Confused? WinISD

[nikg736]

I am going to make a few ported subwoofer projects. I have purchased two of the Peerless and one of the Dayton that follow:

Peerless by Tymphany SDS-135F25CP02-04 5-1/4" Paper Cone Woofer

Dayton Audio DCS165-4 6-1/2" Classic Subwoofer 4 Ohm

According to the site below, SBB4 is supposed to yield a larger box with lower tuning, SC4 about same enclosure size and tuning as SBB4 but different f3, and QB3 has smaller box and lower f3.

Bass reflex alignments explained - Step by step | Audio Judgement

I am currently trying to model for the Peerless in WinISD. I put in those three alignments, but I am confused.
SBB4 comes out with 0.104 cuft enclosure and 57.7 port tuning
SC4 is 0.146 cuft and 56.3 port tuning
QB3 is 0.145 cuft and 55.9 port tuning
The results from WinISD seem to contradict the website, especially with regards to the SBB4 -- it is a smaller box with higher tuning??

So a few questions:
1- Is the website wrong or am I missing something?

2- What would be a good alignment for these Peerless?

3- Might the same alignment be good for the Dayton?

4- Now that we have some good computer modeling options, how important is it to stick to a particular "alignment" at all? I have been playing around with WinISD with regards to box size and port tuning. I made an example with 0.20 cuft box tuned to 50hz where the graphs look pretty good. It would theoretically play deeper and cone would not go beyond Xmax until a lower frequency which I like. Of course overall there is a loss of some SPL.

Thanks

 

[conanski]

IMO.. classifying sub boxes into slightly different categories is a fools errand, build whatever custom alignment that fits your needs/desires and don't give it a seconds though, there is no right or wrong.

 

[nikg736]

Thanks I went ahead and started building.

 

[Promit]

Yeah don't worry about alignments. Work with the box size and tuning to get the response you want (transfer magnitude, overall SPL, max SPL) in the size you can accommodate.

 

[nikg736]

Seems like the alignments were much more useful rules before the age of software modeling. A set of options that yielded generally good results. But now we can use the software to model certain outcomes. Of course models dont always reflect actual results because of differences in driver specs etc. But for me they should be good enough. Not like I am taking a total stab in the dark about enclosure size, port size and tuning.