Acoustic Guitar Construction

Sorry Ken, You lost me there. What I was pointing at, was first: admire a parlor for its own qualities, and bass response is not one of them.
And second: If you are still intended to alter the frequencyresponse you could look at the soundholesize. It is not something I come up with. Quote from Somogyi: "Diminishing the size of the port lowers frequency of the airmass and the guitar's sound becomes bassey and muted. Enlarging the soundhole raises the resonance of the body cavity and will make the guitar's response bright and shrill."

What I am mentioning (and I know little about it ) is that one suggestion is to add a sound port, I believe the same/similar effect as making the sound hole larger --which increases the air resonance that in turn increases treble frequencies --- how does that then improve bass response? Just making conversation.

Ok Ken, I see what you're at. But the above is in contradiction. Ken Hundley wrote that he expierienced more bass by adding a sideport. Which is as enlarging the soundhole.
My point was that making the soundhole smaller helps the bassy side.

What to make out of that? Maybe a sideport does not increase the part of the bassfrequencies in an absolute number, but it may lead the projection right to the player. Therefore it could suggest an increase of bassresponse. I don't know. One should measure that for instance. Is there anyone here who has the tools for that?

I made me a jumbo that should have low tendency for feedback, while playing next to a loud bassamplifier. It has a bigger soundhole (11cm, 4 1/3") and that reased the soundboxresonance for 1/2 a note. And it does have little feedback in the band.

One other suggestion about the parlor: make it electric and alter the amplified frequencies as you like.

Long scale?

Use bluegrass strings with bigger low strings?

Are you talking about a 'real' parlour' as in real small or 0 or 00 size?