Bandpass Question

[PaulO2288]

In here in this topic you can see the front cabin for the subs are larger than the back by far. How does that work with making a 6th order or 8th order of in gerneral what it does? If I was to build a 6th order, and tune to 60hz, can I tune both front and rear cabin to 60hz?

http://audioforum.termpro.com/topic/35/1192.html

[Decaf]

usually you would tune to two different frequencies (your bandpass)

so lets say front is 55, rear might be 40, vis versa

im not positive but i dont think you tune them the same hz since they are different volumes

found this:

The transient performance of 6th order bandpass systems is usually worse than the sealed, ported and 4th order bandpass systems, making it more suitable for sound reinforcement, multimedia and other less critical applications, rather than high-end audio. Like ported systems, the driver becomes unloaded at frequencies lower than the passband.(so if you tune to 60hz you wont be able to get down past 50hz i bet)

As all of the output of the 6th order bandpass system is via the two ports, the largest port diameter possible for each volume should be used in order to minimize port noises.

[PaulO2288]

usually you would tune to two different frequencies (your bandpass)

so lets say front is 55, rear might be 40, vis versa

im not positive but i dont think you tune them the same hz since they are different volumes

Because I was thinking of makeing the front and back the same size and same frequency tuneing.

[unknownuser200985]

if your talking about that one... its Eric Alexander's setup.. an amazing setup.. which is were i based my bandpass off of... front chamber usually has fairly larger airspace as well port area and is tuned much higher... the rear chamber is smaller and tuned much lower less port area... there usually at least an octave apart in tuning ... his rear chamber is tuned to 22hz.. not sure about his front.. when designing mine... the front chamber was 9 cu ft per sub tuned to 45hz with a 137.5 sq inches of port and the rear chamber was 5 cu ft tuned to 19hz with around 50 of port area .... alignment is a key issue as well other things... basically if u don't know what Ur doing ... its not gonna work and either way... more subs and higher the order the harder it is to design... the bigger it is... and the more of a pain the ass it is lol

[PaulO2288]

Alright so maybe you guys can help me. Bulding the box isent the problem its tuneing is the problem. Im building a 6th order bandpass for spl burps only. My resonant frequency is 68hz, so im tuneing to 60hz to hopefully peak at my resonant. Could be doing that wrong, please correct if I am. If someone could possibly help with what to tune each chamber to it would be great. Ill make a design of the box im doing.

[PaulO2288]

Like this for example. Disregard port lenghts as they are not tuneing length.

[PaulO2288]

Anyone know where to find out how to find the resonant frequency of your car/truck without metering? I know measureing the lenght from window to window, but couldent find the rest from searching.