12cxn88 design in WinISD

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   Hello guys! I'm trying to simulate a BR enclosure with this driver in WinISD, focusing only on the 12" parameters. I have 2 questions:
I've found a compromise of cutoff frequency, port size, enclosure size and port velocity that I like. The thing is that when I apply maximum voltage the driver can take, I'm only utilizing 50% of the Xmax of the driver, is this an indication of a sub-optimal alignment?

The box tuning freq is at 80% higher than the driver FS.

The simulated response has a 4 dB bump near tuning freq that falls off slowly within 2 octaves upwards. Is this too much of a resonance to sound good?

https://www.audioxpress.com/article/test-bench-b-c-speakers-pro-sound-12cxn88-12-coax-driver according to this website the physical xmax of the driver is 5,25 mm, which is much closer to the number I'm getting at full power in WinISD, is this number more accurate/important than whats specified by B&C?

Thanks for any advice.

Edited by osse - 09 January 2019 at 11:18pm

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osse Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 26 August 2013 Location: Sverige Status: Offline Points: 84	Post Options Post Reply Quote osse Report Post Thanks(0) Quote Reply Topic: 12cxn88 design in WinISD Posted: 09 January 2019 at 10:54pm
	Hello guys! I'm trying to simulate a BR enclosure with this driver in WinISD, focusing only on the 12" parameters. I have 2 questions: I've found a compromise of cutoff frequency, port size, enclosure size and port velocity that I like. The thing is that when I apply maximum voltage the driver can take, I'm only utilizing 50% of the Xmax of the driver, is this an indication of a sub-optimal alignment? The box tuning freq is at 80% higher than the driver FS. The simulated response has a 4 dB bump near tuning freq that falls off slowly within 2 octaves upwards. Is this too much of a resonance to sound good? https://www.audioxpress.com/article/test-bench-b-c-speakers-pro-sound-12cxn88-12-coax-driver according to this website the physical xmax of the driver is 5,25 mm, which is much closer to the number I'm getting at full power in WinISD, is this number more accurate/important than whats specified by B&C? Thanks for any advice. Edited by osse - 09 January 2019 at 11:18pm

Pasi Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 25 April 2010 Location: Knutsford Status: Offline Points: 2685	Post Options Post Reply Quote Pasi Report Post Thanks(1) Quote Reply Posted: 10 January 2019 at 8:55am
	With a low Qts driver like that, the resonance bump at tuning is indicating too big box and it won't sound good with 4dB peak. But when you reduce the box volume, your port gets longer... High tuning not only sounds bad plus it explains your reduced Xmax figures. Of course you can go ahead and build one & listen, but i wouldn't personally bother.

Zead Members Profile Send Private Message Find Members Posts Add to Buddy List New Member Joined: 08 November 2024 Location: Nyc Status: Offline Points: 2	Post Options Post Reply Quote Zead Report Post Thanks(0) Quote Reply Posted: 24 August 2025 at 2:12pm
	Hi, wanna do similar design. Mind sharing volume and port size you settled on?

Larry23 Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 07 August 2023 Location: Bristol Status: Offline Points: 95	Post Options Post Reply Quote Larry23 Report Post Thanks(0) Quote Reply Posted: 24 August 2025 at 3:26pm
	Not sure if this is helpful - the box I modelled for that driver is 40.1l, tuning 55.7hz. F3 is ~53hz. Port velocity ~22 m/s with port area 75mm x 100mm, length 279mm. Seems to give a relatively flat/extended alignment, with good control over cone excursion, and sacrifices as little as pos efficiency wise. I use the 12NDL88's in similar cabs, slightly different alignment, and they work very well.