Driver Vd vs sensitivity - technical questions

[ACUA]

I have to skim read a book like that because of the math content. I have read many books like that. I do get lost often because to truly understand you must be able to follow the math as well. I cannot keep up with the math. Like I said, there is enough verbal explanation and content that the book is follow-able and I really enjoyed it, despite struggling to chop through the mathematical dialog. The book is easily 1/4-1/3 mathematical material. On one hand it made for a quick read, on the other I am still missing key concepts as a result. I do appreciate you sharing it with me for sure! It would be cool to have all of this laid out on an excel file or in Matlab. I have BassboxPro/XoverPro which is a functional GUI to work through many of these engineering problems for loudspeaker designing. I have not used with any success the HornResp program but surely it functions as basically the same thing!

This whole thread started largely relating to the car audio scene. I really enjoy the car audio situation in that the cabin gain aspect really lets the low frequencies develop for very little expense. I enjoy competition and the idea of using my knowledge to participate is entertaining. The problem with those car audio competitions is the way that they are structured. It always comes down to who has the most money invested every time! I wish I had the engineering and mathematical chops to develop an equation that calculates the cabin space of a given vehicle, electric power, driver Sd and Vd all into one neat package that could be compared to a peak spl that is generated and associate the frequency used to establish a ratio of output relative to equipment used. For example, a system that generates 130dbspl at 30hz may actually be outperforming a vehicle doing 150dbspl at 80hz if we can prove that mathematically 30hz is harder to achieve relative to the spl observed. I also would place into the algorithm a frequency range aspect, like make each competitor run a frequency sweep and collect an RMS spl level and if a guy could generate 180dbslp in only a very narrow frequency range he could still loose to a competitor who generates the full spectrum at some lower level, like the RMS across the spectrum is in the equation with a peak value that the algorithm kicks out a figure expressing that something like 130dbspl RMS wide band may be equal to 150dbspl narrow band or something. This would let a guy making 100dbspl capable of competing with a guy with 160dbslp. A perfect score would be something like 1:1, equal input to output. Since that is not possible a ratio is created to determine who has the most efficient system or setup and that could cater to people less financially inclined. I am not against stupid vehicles with 20+ drivers on a theoretical 60+kw. I just want the trophies to exist equally for any pocketbook size. To me surely it could be calculated so that a guy with a ton of electrical power and less Vd in a small car can compete equally with a person with little power but maybe a ton of Vd in a bigger car and the math equation used to calculate a systems performance determines the victor in a fair reliable way!

[Radian]

With car audio competitions, treat it like it’s not about the audio, sound, or music.

It’s a game like any other. Those showing up with more money (hardware) are likely to be the ones with business on the line in some form or another (vendors, manufacturers, influencers, etc.)

As with any game, I’d recommend starting with the rules and working back into the development of the tactics…not the other way around.

And just like any game, the recreational participants will always be seemingly blown away by the full-time players…resultant of the level of commitment.

[Tom Smit]

I understand what Radian is saying.
I like what ACUA is saying.

[Seth]

...make each competitor run a frequency sweep and collect an RMS spl level...

I agree, that could (should) be a class of competition. Average SPL over a frequency range. Or measure peak SPL while maintaining less than 10% THD and also keeping response within a set dB range (+/-3dB, for example) of a designated target response curve.