Wayne Parham Messages: 18789 Registered: January 2001
Illuminati (33rd Degree)
What you propose sounds like it would work pretty well. You would lose a couple synergies that are designed into the three π and four π models though. And you would need to test your design with acoustic measurements, paying special attention to the lower midrange. I think you'd be alright there though, because your cabinet is small enough that it would have relatively high-frequency standing waves inside, and those would be attenuated the fiberglass stuffing material. The standing waves are potentially problematic in larger cabinets.
The synergies I'm talking about are matching the baffle step with the flanking sub rolloff, which both conjugates baffle step and mitigates higher-frequency room modes and self-interference notches from nearest boundaries. This is what you get from the existing three π and four π designs when used with flanking subs.
A smaller baffle will have baffle step higher in frequency, and you wouldn't want to run flanking subs high enough to fill in that gap. So there will be a little bit of a droop between the flanking sub upper frequency and the baffle step frequency.
But you might still give it a go. I wouldn't try to compensate for baffle step with an electronic filter, I'd just live with the droop and see if it was objectionable. My guess is it would sound just fine.