Help modelling subwoofer?

Hey Folks,
I would do this myself but I don't have access to a windows computer right now and I need to make a decision in the next day or so.
I'm looking at the RSS315HE-22 dayton subwoofer.

I've tried having a play with hornresp (I actually managed to make it work on my mac), but have had no luck with WINISD.
It looks like a very small sealed box, ~25L gives a Q= .7, but it reaches max displacement really quickly.
My biggest issue is that I don't know how to model a bass boost for a sealed system in hornresp.
I've tried playing with a ported box, and ~80-90L gives a good response, but the port ends up being very very long to reduce port velocity below 17m/s.

Could someone have a quick bash at modelling this and seeing what an optimal design would look like?
I tried searching on the forums for previous modelling and didn't find much if any!
I'm looking for <100L Box with decent response down to 20hz.
I know I'll need a heap of wattage to make this happen. A 105dB Max output would be perfectly acceptable for me.
A small(ish) box is the main priority.
I will have DSP available.

Thanks for your time, even if it was just giving this a quick read.

T/S max flat:

Vented net volume (Vb) (L) = 20*Vas*Qts'^3.3 = 50 L

Vented box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96 = ~28.3 Hz

F3 (Hz) = Fs*0.28*Qts^-1.4 = ~26.6 Hz

Yes, extremely long as in TL long with 2x Vb (100 L) dropping Fb = ~21 Hz, lowering vent mach and factoring in only needing ~120 W/105 dB/20 Hz/2 pi it still needs a 'critically damped' 5" i.d. dia. vent x 31.1"/79 cm long, ergo ideally needs a single 15" or dual 12" passive radiator(s).


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Thanks gents.
Jeff, that seems a very reasonable vent size and frequency response. Especially when you add in some room gain around the 20hz mark.
How is the vent not stupidly long like I (and GM) found?
Are you able to see how much power it takes before xmax limit?
Joined 2001
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How much EQ do you have?

It will work in 25-50 itres sealed and get you into the mid 20s F10, a good measure of where it will go in room.

I prefer sealed + EQ for subwoofers (ideally you have at least 2).

A 50 litre vented alignment tuned a bit lower than GM suggests gives a more damped response. 25 Hz in the sim below.

Screen Shot 2023-09-18 at 19.15.34.png

How much EQ do you have?
It'll be full digital.

I assume a vented alignment would require a HPF. Probably either option to be honest.

The plan is to have 2 of them, in a 6m x 9m living/dining room. They'll both be within 2m of the sitting position, in different corners/room positions.

I was thinking sealed pushed to f10 at about 25hz, then adding a modest EQ boost of 6dB + room gain would actually pull it down pretty neatly to close to 20hz. But vented would also work very similar.
This is for 50/50 Music & movies. My biggest issue is size of enclosure and I'm just trying to make the best compromises I can.
Joined 2001
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sealed pushed to f10 at about 25hz, then adding a modest EQ boost of 6dB + room gain would actually pull it down pretty neatly to close to 20hz

That is where i went with mine. It may well be more complex than that. Your room is pretty large, ceiling?

You may well not need a ot of lift, but room modes, even after you get the 2 subs placed so that they have the smoothest response you will likely still need a bit of tweaking here & there.

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