hispls 5,000+ posts
CarAudio.com Veteran
Most actual music played on musical instruments will contain little to no material below 40hz. Even most EDM music I've played will not dip below 35hz. If you do not plan to listen to "bass mechanic" type music or slow speed recordings or similar 35-36 should be plenty low to handle pretty much anything that would play on the radio.So 30 is a bit low tuning for normal music, and people tell me 45 is too high because then it will not play the deep notes, so 35 can be a good solution? Remember, for me the only real bass i need is the one you can feel outside the car, not only hear, but feel too! Sorry for my english, i'm in italy
I would agree that 45hz tuning is going to be a bit high for a good range of music. That and higher tuning is typically reserved for SPL burp applications where you're aiming to just play very loud around your car's resonant frequency which usually is 50hz or higher for most common vehicles.
Anyway, you will notice that some horn/string instruments will play 30hz and lower but if your goal was to reproduce a concert hall sound, you could still get loud enough to be realistic even with higher tuning as the port will control the cone a good bit below tuning frequency.
I believe if you build the box in your picture, make sure the seems are airtight, and everything is solid (add a support/brace between the two woofers to the back panel) you will not have a problem playing just about any music very loud.
You may even find that box is a little too large and you begin to approach mechanical limits of your woofers with so much power on tap. If you do, you can always just add 45 degree pieces into the corners to remove some box volume and add layers to the inside of your port to shrink that as needed to keep your tuning ratio.
I can assure you, your English is better than my Italian!