posted
I was just brainstormin sittin here thinkin, one major disadvantage of ported designs is port tuning.
Sure u have port adapters but it involves physically putting it in and out.
What if you were driving and wanted to listen to 2 songs but each song's strong points are in 2 different parts of the frequency range, one may be awesome loud whereas the other may not be.
This may sound impossible because for I, I would have no idea how this would work, but here it goes-
Build ur box, cut ur hole, use some sort of material that changes form with turbulance.
Such as, if u were playing a 30Hz test tone, this material would extend itself to specifically peak at that frequency. Then play a 60Hz test tone and it would shrink itself to peak at that freqeuncy as well.
Kinda like a Universal port tuning box. It constantly changes it peak according to air flow.
Anyone ever think of this and have any slightest idea over impossible where it might be possible and with what?
posted
Umm... i guess it could be done but all the chemical/material research would probably cost you a hell of a lot more than a sleeve for the port and a linear actuator and a controller =P Think "those swords you had when you were a kid that expanded and stuff" those things go from like 8 in to like 5 feet so i'm sure something of that type can cover your tuning needs. The hard part will be figure out a way to control it accurately unless you have a wall or something where you can see the port without crashin the car. I have thought about doing something like that for a while but i havent really found out a way to make the ports nest together well without any sharp edges and without being too thin. Braced masonite maybe? If you try let us know how it works out.
Posts: 124 | From: Arizona | Registered: Oct 2002
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posted
impossible....music changes frequency wayyyyy to quickly for any material to change. Maybe you could mechanically switch out the port to a pre-determined size for each song...if you get what i'm sayin. Like have 5 ports of different sizes rotating around or something i dont know...
Posts: 429 | From: San Diego, CA | Registered: Apr 2004
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posted
The closest and best results I have had with this situation, is with the 'wicked one' box. It is a dual , 4th order, horn loaded bandpass box. You can see it on Decware.com. The box lends itself to a wide range of bandwidth very smoothly. What I did , was to add the MTX lsb-1 ( hard to find!) , and with this, I was able to dial and boost any frequency I wanted. The box simply responded to the processor's command. For spl, I dialed in 52 hz and boosted the center of that note way up. For music, I dialed in 33hz and boosted it until it was even with my highs. So, instead of a space age box, I use a flat rsponse box with a high quality eq to do the tuning and boosting with.
quote:Originally posted by AstroMan: Umm... i guess it could be done but all the chemical/material research would probably cost you a hell of a lot more than a sleeve for the port and a linear actuator and a controller =P Think "those swords you had when you were a kid that expanded and stuff" those things go from like 8 in to like 5 feet so i'm sure something of that type can cover your tuning needs. The hard part will be figure out a way to control it accurately unless you have a wall or something where you can see the port without crashin the car. I have thought about doing something like that for a while but i havent really found out a way to make the ports nest together well without any sharp edges and without being too thin. Braced masonite maybe? If you try let us know how it works out.
As for your ideas, I think it would be easier to change the width of the port than the length. If you had a very smooth top and bottom, you could theoretically set up one side to slide left and right. It could have a piece of wood parallel to the front of the box attached that slide right behind the front of the box. Cosmetically, it would be .75" back from flush for a single layer baffle, but the airflow in the port would be smooth. The main issue would be how to seal it. Personally I don't think it's worth the effort. It would eat up a fair bit of the baffle, necessitating a large box and plenty of space around the subs for the actuator(s), etc.
I have, however, heard of boxes with a motorized plate to convert from ported for SPL to sealed for SQ. I believe I read about it in a magazine. I think Kicker Solobarics were used, but I'm not sure which size or model.
posted
I wasnt thinking it of changing on the fly, just by adjustment. Good thinking though, but i think it would work either way if done correctly
Posts: 124 | From: Arizona | Registered: Oct 2002
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posted
i used to have a Petras Mr. Q bass processor and i was able to change the freq. on the fly and even with a ported box changing it you could make the bass tight and hard hitting with rock music and on rap you could adjust it to make it boomy or how ever you wanted it
posted
use a passive radiator i use 2 15" prs in my car on 1 15" rf hx2 best spl to date is 142.5 and they can be tuned easily just add weight i can tune from 11hz up to around 50hz in my box
Posts: 61 | From: Buffalo NY | Registered: Jan 2004
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