Beyma 8NMFW quad

Hard Data
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Took an average of the 4x T/S for the quad of 8NMFW and did a model.

Re 5.3608

Fs 42.3280

Spl 87.2345

Qe 0.3796

Qm 8.85795

Qt 0.3639

Le 1.1259

Vas 18.3616

Bl 13.7778

Mms 50.7498

Sd 214.08 as my normal measurement is calculated. The spec seems a bit high to me.

Using 2 woofers in a 42ltr gross box for size requirements, and then reducing by bracing, driver magnets, ports, and pending xovers; 38 ltrs tuned with a 3"D x 8 25" L port tuned to 37Hz yields an F3/10 of 37/25 Hz. With output to 105dB not breaching xmax and port mach remaining below chuffing threshold, this was a surprise in the required volume and port size.

I did model a PR box as well, but it would not extend as low. However, I found that the SS10PR would likely be a good PR for non-subwoofer alignments because it can tune higher than the RSS265PR is capable.

I’ll post the graphics later from the laptop, but wanted to post my findings.

2 Likes
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I’d be interested in those graphics Ben. Still have my eye on this series come the next worthwhile sale from PE or elsewhere.

Curious how you calculate Sd. I’ve seen some recommend including half the surround in the calc but I always thought that felt optimistic. The radiating area technically includes that but for modeling purposes I imagine the actual effect is small.

I also recently noticed that about the SS PRs. I feel like that is convenient and a good pairing to the RS series, between them it gives a lot of flexibility.