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.
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.
I installed a SCT X4 87 octane tune earlier this month. The tuner has 93 octane and e85 tunes too.
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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.
Mazda Miata 2.0L engines are in NP01-EVO and NP01-Spec cars.
I do this at EVERY restaurant I go to!
by Ivan
— If you pay attention to the ceiling speakers while getting a salad.
by Ivan
— If you pay attention to the ceiling speakers while getting a salad.
Hey DMB,
Parts Express says the recommended sealed enclosure is 3.75ft3 for the GRS 18PT-8.
Based on the advertised 350rms and 6.8mm Xmax, HR is stating 1.56ft3 is the maximum volume.
What is the issue?
Parts Express says the recommended sealed enclosure is 3.75ft3 for the GRS 18PT-8.
Based on the advertised 350rms and 6.8mm Xmax, HR is stating 1.56ft3 is the maximum volume.
What is the issue?
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?
How are they not?
If the manufacturer or seller says 350wrms & 6.8mm Xmax, then I do not expect them to recommend an enclosure that EXCEED those numbers.
3.75ft3 = 10.66mm Xmax @ 350wrms according to HR.
If the manufacturer or seller says 350wrms & 6.8mm Xmax, then I do not expect them to recommend an enclosure that EXCEED those numbers.
3.75ft3 = 10.66mm Xmax @ 350wrms according to HR.
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. 😊
Dude, the model is in post #14,512.
How do you think I got the 10.66mm excursion???
3.75ft3 x 28.317L = 106.19L.
And, I used 350wrms @ 6.9ohm.
How do you think I got the 10.66mm excursion???
3.75ft3 x 28.317L = 106.19L.
And, I used 350wrms @ 6.9ohm.
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...
It appears that they have, in this case.
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.
This is a SUBwoofer thread.
If you are going to provide an example, then use a SUBwoofer and not a midbass that plays to 90hz.
Pmax should be targeted in the 20-80hz range, not >80hz.
The recommended enclosure SHOULD have an ALL BLACK line in this graph to prevent driver destruction.
If you are going to provide an example, then use a SUBwoofer and not a midbass that plays to 90hz.
Pmax should be targeted in the 20-80hz range, not >80hz.
The recommended enclosure SHOULD have an ALL BLACK line in this graph to prevent driver destruction.