I have built many sealed boxes but i want to build a ported one. I have found calculators and stuff but i want to know about Hertz. What 'Hertz' do you guys usually go with? What is the difference between high and low values of Hertz?
Yeah. Low frequencies tend to have more SQ because they can drop lower w/o port noise, higher frequencies around 35-40 hz are what gives more SPL, since sub's resonant frequencies are usually in that region, that's what people tune them for to get SPL.
28-36Hz is a good spot for low bass. 45Hz is common for rap and harder hitting stuff like electronica, but it can sound boomy if you're after a deeper more accurate sound instead of just loudness. 55-70Hz sounds like crap, but it's at the Fs of the vehicle cabin, and you get teh highest gain here. This is where SPL competition cars tune bandpass ports to get the most volume. Not recommended for a daily driver setup.
what is the advantage of having it way up high like that, if it has higher volume than more people can hear it?
also you said rap is 45hz, but people who like rap like the really low and deep stuff too. what will be the difference between how hard it hits from 35-45 hz
tuning in the 50Hz+ range is for SPL competitors who compete by seeing which system is teh loudest on an RTA meter. The idea is to tune the box to the same frequency as the cabin of the vehicle's free air resonant frequency, thus capitalizing on getting the most gain out of the vehicle it's self. SPL competitions are all about physics at the higher end of competition.
Most rap music and electronica centers it's bass at a higher frequency than you may think. Usually closer to 45Hz. What sounds deep to you may not really be that deep, and without an RTA, you really don't have any way to tell.
If you want to feel some really low bass, pick up a copy on CD of pink floyd's Dark Side of the Moon. The heartbeat at the very beginning of the CD is a 20Hz tone. When it starts, you don't hear it if you have a good system, but you'll notice it's hard to see out of the car. Everything gets blurry from the resonance the tone produces. I used to use that CD as a demo (MFSL 24K Gold pressed edition) in my competition car. It was fun to see the look on someone's face when they noticed it was hard to breathe, and they still didn't "hear" anything.
glasswolf what do u mean if u have a 'good system'. woudl the w 12" RE x-X-x's im getting be able to do that? and would i onyl get that ' not being able to breathe' quality if my box was tuned to 20 hz?
my box was tuned to 30Hz. If you'd get that effect entirely depends on the amp you use for those subs, along with the rest of the system, and the vehicle you're using. If you can meter at around 150dB then yeah you'll be there too.