Nice looking project the most adventurous I ever got with car software was writing an auto tuner for my Haltech ECU before Haltech even had one.In that case, you might be interested in the Lap Simulator I developed some years ago.
You probably wont believe this, but I swear that it is true. The fastest that I actually physically lapped the circuit in my 1969 Mini Cooper S in standard road trim was 1 minute 23.8 seconds, achieving a speedometer reading of exactly 100 mph at the end of the longest straight.
The "best guess" inputs that I initially entered into the simulator for the Mini Cooper S are as shown in the attachments. Amazingly, as you can see, the predicted lap time is identical to the actual time that I had achieved more than 40 years prior, and the actual and predicted top speeds are effectively the same also, taking into account that speedometers are normally conservatively calibrated to read slightly high.
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No idea when I starting writing this program, must have been at least 10 years ago because I don't even remember writing it. Doesn't look like I got too far.
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I understand, it’s your baby, it would have been interesting to learn from you / it as there just aren‘t many folk left from those days. You have sent me on a journey today reading more about horn theory, I have already revisited some old texts that make more sense to me now, as it does each time I revisit a topic.
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I wish!
My local track is pretty ordinary, and certainly no F1 circuit...
Coincidentally, the Australian Grand Prix is on this weekend - go Oscar Piastri and (hopefully) Daniel Ricciardo!
Unfortunately even with all the controversy surrounding Christian Horner I can't see how anyone is going to beat Max Verstappen in the Red Bull.
max thermal power, Xmax and sealed enclosure volume are not really related.
small chamber may keep Xmax within limits with the specified power (or input voktage, to be precise), but what sense does this make?
just have a look at the manufacturer vented recommended box and see what excursion you get below box tuning.
Every speaker will run out of excursion at a certain level, far below thermal power limit, once the frequency is low enough.
Also, did you see that at the closed box tuning frequency the impedance peak will drastically reduce the input power (still at the same amp output voltage)?
Try simulating the recommended closed box with constant 350 W power and look up the excursion...
It's your responsibility to design a system or regulate the volume knob to keep the loudspeaker in its safe range.
Every speaker will run out of excursion at a certain level, far below thermal power limit, once the frequency is low enough.
Also, did you see that at the closed box tuning frequency the impedance peak will drastically reduce the input power (still at the same amp output voltage)?
Try simulating the recommended closed box with constant 350 W power and look up the excursion...
It's your responsibility to design a system or regulate the volume knob to keep the loudspeaker in its safe range.
There is no issue, as far as I can see.
Pmax and Xmax are separate parameters. Either one can limit the performance of the loudspeaker system. The Maximum SPL chart attached shows the response initially limited by Xmax (red trace) and then at higher frequencies by Pmax (black trace).
Pmax is the maximum thermally-limited power that the driver can tolerate without the voice coil being damaged.
For the driver you have specified, Xmax is calculated as follows:
Xmax = (Voice Coil Length - Top Plate Height) / 2 + 1 / 3 * Top Plate Height
Two completely different parameters...
that's just your assumption, but it's not common to do so.
Just an example:
I have a small dayton dsa-135 woofer.
Specified rms (thermal) max power: 50 W
specified Xmax: 4.9 mm
Using a closed chamber (Qtc=0,707) the max Spl is excursion limited below 135 Hz.
At system resonance (90 Hz) the max. input voltage to reach Xmax is 15 V, equalling 28 W at 8 Ohm.
But the actual impedance is about 32 Ohm at 90 Hz, so the driver only "consumes" 7 W.
If I would be crazy enough to connect my little woofer to a 200 W amp and play a 40 V rms 90 Hz tone the driver would get the full specified 50 W. But calculated excursion would be 12 mm, which means the driver will be probably damaged beyond repair.
Manufacturers recommend enclosures with flat response, not enclosures that allow the driver to be driven at specified limits under all cicumstances.