Ok, guys, I'm sure that I'm over-thinking things but I haven't designed a side-firing woofer before. Hopefully someone can set me straight. Please bear with a rather lengthy explanation as I meander around to the questions.

I'm working on a three-way in a tall box. Basically, it's a 4' tall, 10" wide, 14.5" deep box with the mid located near the top of the box and the woofer on the side roughly half way from the floor. The woofer is ported on the front of the box near the floor. FWIW, the woofer is an SB29NRX75-6 (spec sheet is here).

I have constructed a prototype box, taken measurements, and started working on the XO. Taking the mid and tweeter measurements is easy enough but I'm not sure what woofer measurements to use in the XO design.

The below shows measurements for NF woofer (green), NF port adjusted for relative woofer diameter (mustard), and summed response (blue).

I then adjusted the combined NF down to a theoretical 1 meter SPL shown below (purple). I also took a 1 meter woofer/port measurement on the mid axis (red) primarily to get an idea of the distance/delay (thinking of acoustic centers here) between the mid and woofer. The delay seems to be slightly more than 8".

[Note that all of these are MLS measurements (at 2.834V with a calibrated mic) and actual SPL is, therefore, 3dB higher.]

The low-frequency limit of the FF woofer/port measurement is a bit under 200Hz. The NF curve is theoretically useful below roughly 500Hz (based on D'Appolito's white book if I did the math correctly). The on-mid-axis measurement is, of course, more than 1M from the mic.

Finally, I plan to cross-over to the mid at 250Hz or below. While wavelengths are long here, I'd like to keep things in phase as much as possible.

So here are the questions: Should I design the XO using the NF curves? Or should I take FF on-axis woofer measurements and splice with the NF for XO design? Given that low order filters will allow significant woofer output (side-firing and reflecting off of whatever surfaces are nearby) into, say, the 1kHz+ region, what acoustic order would you target?

I'm sure that more questions will come to mind just as soon as I post this. In the meantime, thanks for any advice.

I'm working on a three-way in a tall box. Basically, it's a 4' tall, 10" wide, 14.5" deep box with the mid located near the top of the box and the woofer on the side roughly half way from the floor. The woofer is ported on the front of the box near the floor. FWIW, the woofer is an SB29NRX75-6 (spec sheet is here).

I have constructed a prototype box, taken measurements, and started working on the XO. Taking the mid and tweeter measurements is easy enough but I'm not sure what woofer measurements to use in the XO design.

The below shows measurements for NF woofer (green), NF port adjusted for relative woofer diameter (mustard), and summed response (blue).

I then adjusted the combined NF down to a theoretical 1 meter SPL shown below (purple). I also took a 1 meter woofer/port measurement on the mid axis (red) primarily to get an idea of the distance/delay (thinking of acoustic centers here) between the mid and woofer. The delay seems to be slightly more than 8".

[Note that all of these are MLS measurements (at 2.834V with a calibrated mic) and actual SPL is, therefore, 3dB higher.]

The low-frequency limit of the FF woofer/port measurement is a bit under 200Hz. The NF curve is theoretically useful below roughly 500Hz (based on D'Appolito's white book if I did the math correctly). The on-mid-axis measurement is, of course, more than 1M from the mic.

Finally, I plan to cross-over to the mid at 250Hz or below. While wavelengths are long here, I'd like to keep things in phase as much as possible.

So here are the questions: Should I design the XO using the NF curves? Or should I take FF on-axis woofer measurements and splice with the NF for XO design? Given that low order filters will allow significant woofer output (side-firing and reflecting off of whatever surfaces are nearby) into, say, the 1kHz+ region, what acoustic order would you target?

I'm sure that more questions will come to mind just as soon as I post this. In the meantime, thanks for any advice.

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