is there a maximum particle velocity before which chuffing is audible?
Does it differ between design types? 4th BP vs. Vented alignments vs Tapped Tapers?
Im considering a very low tuned enclosure for my mobile build which will move a lot of air at tuning.
further, In hornresp is there any way to model a flared vent. not just a roundover on the port but a 2" radius on both ens
Does it differ between design types? 4th BP vs. Vented alignments vs Tapped Tapers?
Im considering a very low tuned enclosure for my mobile build which will move a lot of air at tuning.
further, In hornresp is there any way to model a flared vent. not just a roundover on the port but a 2" radius on both ens
You can model flares etc quite easily - just add sections to the port.
IMO, it can vary by application. For instance, a 12" PA speaker isn't going to be fed loads of signal at the port tuning, so you can get away with ports that are theoretically under-sized. Most of the power will be elsewhere, but if you did happen to hit it with a full-power signal at port tuning, there'll be some chuffing.
Subwoofers are narrow-bandwidth devices and so port velocity should be kept low.
Chris
IMO, it can vary by application. For instance, a 12" PA speaker isn't going to be fed loads of signal at the port tuning, so you can get away with ports that are theoretically under-sized. Most of the power will be elsewhere, but if you did happen to hit it with a full-power signal at port tuning, there'll be some chuffing.
Subwoofers are narrow-bandwidth devices and so port velocity should be kept low.
Chris
Well, it depends on how that 12" PA speaker is going to be used 🙂. My POC6 for example was designed to do from 50 Hz to around 200 Hz, and has a "vent" that's 2/3rds of the driver's Sd. There's still measurable vent compression, but it's fairly low. Chuffing isn't audible, at least it wasn't the last time I did some testing on it. Hornresp predicts a particle velocity of just under 9m/s.
Note however a TH that I built using the same driver shows something like 0.3dB of compression!
If the aim of the build is to "move a lot of air at tuning.", go with as large a vent as possible, or consider a TH alignment instead. Just bear in mind that the larger the vent, the more midrange is likely to leak through it and the lower the pipe resonances associated with the vent are going to be, and therefore the less useful the build will be for full-range duty.
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