Sealed to aperiodic conversion

[AudioGMan]

Has anyone taken a mass produced sealed speaker and made an aperiodic design out of it with successful results? I’m going to attempt this. The guinea pig speaker is a Sony SS-MB350H.
I first removed the 8” woofer from the cabinet and extracted the T/S parameters. The results were:
Fs: 34Hz
Qts: .59
Qes: .67
Qms: 4.74
Then I re-installed the woofer into the 0.74 cubic foot(net internal volume) cabinet and measured the Vas at 1.907 cubic feet.
With the woofer back in the cabinet the Fs shot up to 63Hz. The Qts rose to 1.17. Impedance peak rose sharply to around 50 ohms.
I’m thinking this speaker might be a good candidate for an aperiodic conversion. I’m going to use a hole saw to drill a hole on the back of the cabinet near the top. Then I will staple some corse screen to the inside of the cabinet. I’ll use fiberglass insulation to stuff the port and then make a removable screen on the front of the port so that I can tune the cabinet for the smoothest impedance curve and maybe get the Qts to the ideal 0.707. The good thing is that I have an extra Sony cabinet to do all this. If it works out good then I will convert my pair of speakers. What do you guys think?

 

[rothwellaudio]

Does your measuring gear allow you to produce an impedance plot? My experience has been that it very easy to over stuff the port and turn it into a sealed box again. You only need light stuffing to flatten the curve sufficiently. My method was to tune the port as if tuning a reflex speaker, ie two equal humps in the impedance curve, then use stuffing to smooth out the humps. One layer of BAF wadding only about 10mm thick was enough to over stuff it and I had to peel apart the layers to get it thinner. Even one layer of cloth over the port effectively sealed it off. However, my drivers had completely different T/S parameters to start with. It might be easier with your's.

 

[AudioGMan]

Does your measuring gear allow you to produce an impedance plot? My experience has been that it very easy to over stuff the port and turn it into a sealed box again. You only need light stuffing to flatten the curve sufficiently. My method was to tune the port as if tuning a reflex speaker, ie two equal humps in the impedance curve, then use stuffing to smooth out the humps. One layer of BAF wadding only about 10mm thick was enough to over stuff it and I had to peel apart the layers to get it thinner. Even one layer of cloth over the port effectively sealed it off. However, my drivers had completely different T/S parameters to start with. It might be easier with your's.

Thank you for your reply. I am using the Dayton Audio WT3 software so yes it does show an impedance plot.

 

[Gibsonian]

I like it. Speakers seem a very good candidate