Different length aeros?

[KHARPS 10+ year member]

This may be a dumb question.....but I already have a 3'' aero cut to 15'' in length. For the box I'm building I need (2) 3'' aeros at 16'' each. So what would happen to the tuning/sound if I left my new aero at full length (18'') and used the 15'' one with it?

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[KHARPS 10+ year member]

up

 

[groundpound4200 5,000+ posts]

I dont know what will happen but I cant imagine it going well

 

[80INCHES 5,000+ posts]

hmmmmmm well thats wat some of the tcab boxes use to do...theres a pic posted on roe about tcab boxes and most dual aero port boxes one port was shorter than the other

80

 

[skateboardkid 10+ year member]

what would your tuning be at two 15" aeros?

I think you might get cancellation or weird phase issues with two different legth ports.

OR just go with reg 4" pvc untill you get more funds.

 

[KHARPS 10+ year member]

I can't fit a 4'' because it's for a regular cab truck with the port firing up and I only have enough top depth to do 3'' aeros. If I do both at 15'' then the tuning will be around 40....which is kind of high for daily use.

 

[azimuth 5,000+ posts]

I can't fit a 4'' because it's for a regular cab truck with the port firing up and I only have enough top depth to do 3'' aeros. If I do both at 15'' then the tuning will be around 40....which is kind of high for daily use.

he meant to do (1) 4 inch aero instead of 2 3 inch aero's. are they real aero's or are you using pvc?

 

[Rashaddd 5,000+ posts]

I'm curious what having differently tuned ports would do

helotaxi? immacomputer? one of you people who knows everything about this stuff //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[KHARPS 10+ year member]

he meant to do (1) 4 inch aero instead of 2 3 inch aero's. are they real aero's or are you using pvc?

Yeah I know but my top depth is only going to be 6.25'' which is just enough for a 3'' aero. 4'' aeros require at least 7.25'' of mounting space. They are the Precision Port aeros from Parts Express. The box is for a 10'' BL and I'm using (2) 3'' aeros because the one I made with the 15'' long 3'' aero had too much port noise. But I just re-calculated everything and if both 3'' aeros are 15'' long I'll have a tuning of 38hz..... a little high but it shouldn't be too bad.

 

[KHARPS 10+ year member]

I'm curious what having differently tuned ports would do
helotaxi? immacomputer? one of you people who knows everything about this stuff //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Haha I was hoping helo would see this. He's helped me out a few times //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[KHARPS 10+ year member]

Here's what the box will look like

 

[KHARPS 10+ year member]

anyone else have any input?

 

[Immacomputer 10+ year member]

I'm pretty sure that having two separate ports with different lengths gives different tunings for each port. I don't know how you would separate the two in calculation to find the actual tuning frequency of each, but I'm fairly certain that they would have different tuning frequencies as they're just different masses of air within the same enclosure. The mass of air is one determining factor on how it oscillates so I think I'm correct.

If the lengths are close to each other, then their individual tuning frequencies will also be very close. This could give odd beat patterns when playing a constant tone around those frequencies and the beat will oscillate at the difference of the two tunings. If somebody knows better, let them chime in but I'm pretty sure that's correct.

 

[KHARPS 10+ year member]

Ok, thanks immacomputer. I'll just cut the second aero to 15'' and hope the highish tuning is tolerable.

 

[mcsoul 10+ year member]

I imagine it would yield some mathematical function of the two port length tuning frequencies.

Skewed towards the port with more area if one has it. But Immacomputer's answer sounds better!