i like being asked questions it works out my knowledge
we have a program which we use called bass box pro this allows us to model the response from the speakers then we can tweak and tune to we have a frequency response curve to our liking my aim would be to achieve a flat response from 20-50hz between 1-3 DB per frequency the enclosure I’m using is a series tuned band pass which in a car environment works very well
there will be a basic sound stage in the car with mid and highs at head height for daily listening but it has been mainly an exercise to cram as many in for sheer output in Bass Mid and High Frequency responces
how the SPL is measured i the competition format i compete in is across a frequency range 20hz 25hz 30hz 40hz and the peak frequency spl this is then averaged
this is measured at the headrest and also at the windscreen with a sensor called a termlab
Source material is set by a disc or USB produced by the competition promoter at a 0DB recording so all is fair and there no boosting of frequencies
I see what you mean about maximising efficiency I’ve had a few setups previously with Massive Voice Coiled drivers in a clit dual 3inch drivers rated at 5000Wrms each which is an insane amount of power to put in to a speaker i fed them with 2000wrms each it did get fairly loud achieved 150db at a peak each time i played it the car got a little louder
But there is a drawback to this ok a clit is small so it did get loud but it wasn’t as efficient as my Audi set up and the play time was alot less around half Hour! when you spend X amount on a system i would like to play as long as i like but the driver would get very hot because as the power supply drops off as the batteries flatten you start to induce clip and square waves
My audi setup this was 10 low power drivers 250wrms rated each and a 1.5inch voice coil the total power for this system was 2400wrms a fraction on my clit this peaked at 149Db 1 Db less than the clit but the advantage with this system was the play time! I could play all day and not have to worry about blowing a £1500 Speaker with there was no heat issue as the power supply was sufficient to power the system, I went to Mudded Nationals show with a local car club I had the car on a switching power supply on a genny and played from 9am till about 6PM I was very surprised that nothing let go!
my Audi System
I want the same from this system but on a larger scale and louder scale if im honest i will properly be just as loud with 32 woofers but 48 looks more impressive on the plus side compared to my clit there is 48 coils to share the power and dissipate the heat compared to 4 coils in my clit
then you also have cone area which makes achieving the target SPL a little easier I have the equivalent cone area of 15 18 inch subs if i was to do 15 18s i would need a transit van for it to work at its best lol
i think i have gone on a bit lol
but please ask me more questions i could talk about speakers all day