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4th order bandpass enclosure (fi Q 12")


lyons238

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Posted

I'll disagree on the ratio thing hunter. I'll agree on the rest.

One of the most volent and balanced 4th ever in my life was robin butlers Tahoe. Have other ones been louder? Sure.

But when you can murder 15hz to upper 60hz with a very similar intensity? I don't know it seemed like he didn't have a peak to the ear. I'd want mind to perform like that even if I lost a few Db peak. I hate that my bandwidth is 26-38 with authority. Really 30-34 lol.... But your band pass seems pretty successful also with both bandwidth and output so I'm sure plenty of your points are valid vs my noobish observations.

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Posted

2.4:1 over here.

17-60 flat. But I digress.

1996 GMC Sonoma
Four Fi BTL Neo 18's In 2:1 6th Order Bandpass
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On 10/20/2013 at 0:37 AM, KillaCam said:

Fucking with a Prius driver is like making fun of a disabled kid. Pussies.

Posted

Don't worry about ratios.

b_350_20_692108_381007_FFFFFF_000000.png

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Krakin, are you some sort of mad scientist?

I would have replied earlier, but I was measuring the output of my amp with a yardstick . . .

What you hear is not the air pressure variation in itself

but what has drawn your attention

in the two streams of superimposed air pressure variations at your eardrums

An acoustic event has dimensions of Time, Tone, Loudness and Space

Everyone learns to render the 3-dimensional localization of sound based on the individual shape of their ears,

thus no formula can achieve a definite effect for every listener.

Posted

Don't worry about ratios.

+1

Just because a 1:2 or 1:4 or whatever ratio was right for someone else's setup doesn't mean it will be right for yours.

Hey Raptorman, what where the box specs on your setup? I know it worked out really well and it might give lyons something good to compare against when he plays around in WinISD.

"Nothing prevents people from knowing the truth more than the belief they already know it."
"Making bass is easy, making music is the hard part."

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Posted

24 ported, 10 sealed, 341 sq in of port

1996 GMC Sonoma
Four Fi BTL Neo 18's In 2:1 6th Order Bandpass
2 Ampere 5k's @ .5

TEAM FI
TEAM #LITHIUMCANTDEMO

 

On 10/20/2013 at 0:37 AM, KillaCam said:

Fucking with a Prius driver is like making fun of a disabled kid. Pussies.

Posted

All these sexy 4th order subs and me with no 4th order friendly subs!

I guess I'll just have to buy another ride and 4th order that one!

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On 12/5/2014 at 8:06 PM, juan777 said:

See yall there, I'll be the drunk Mexican with aviators on.

On 12/6/2014 at 10:32 PM, boom50cal said:

I did see Juan LMFAO! He REALLY WAS the drunk mexican with Aviators on!

 
Posted

I'd go between 1.5 : 1 and 2.5 : 1. Id lean more to 1.5-1.75 to 1 ratio. Build 1 side to the sealed Reccomended. Then take that to find the 1.75 part of the ratio. Tune between 44and 48hz. That should still dig down to 25hz. Most people tuning to 42 reach down to 20 and that's much much lower.

Most people with 4ths say to give 16-22 sq inches of port per cube with a slot. (Normal ported being 12-14 sq inches) so if I guess with aero ports (normal ported being 8-12 sq inches of port per cube) so my guess would be to shoot for 14-16sq inches of port per cube with an aero.

Definitely invert the sub.

Power handling depends on the ratio you choose, closer to 1:1 you will lose power handling, lose SPL and gain bandwidth. Closer to 3:1 you will gain power handling (mechanically), spl, and lose bandwidth.

The high qts option and stuff I don't think is needed, I'm sure it could help. I've heard that higher qts subs can handle playing lower below tuning.

If you have an android phone then download the ultimate car audio App from xplicit.

Those are all the questions I could answer off the top of my head. Hope it helps.

Anything below 2:1 is a waste imo. Tuning point is the resonant frequency of your sealed chamber, not just a guess.

Port area is strictly based on your cone area/volumetric displacement, not tied into your ported chamber volume whatsoever.

Yes invert the sub.

Power handling is based on sealed volume/port area. Bandwidth will hardly diminish whatsoever from higher ratios, to a certain extent. 3.5:1 is the most I'd do for musical.

High qts option is Fi's way of saying "Sealed box friendly", which, also means 4th order friendly. So get high qts if you can.

I already have the non qts version, will this still be okay? Also I have a 2000w amp so I figure the sun will see around 1700w, would it be wise to go 1.5 in the sealed portion which is as big as the Q is supposed to see or would something like a 1.25 or 1.3 be better for that amount if power?

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