posted
Before I start, this is just to mess around with, I havent been able to install what i want.
I have this box a local shop built for me a long time ago. I dont feel like goin out to measure it right now but they made 1 port for it, tuning is unknown.
Well, anyways, back a long time ago, i wanted to add another port and the way i thought was to add another one, same length and all and it would add 3 db, hehe Dont u love assumptions, :-)
Well anyways, now the present time, i am using this box as a temporary setup just until it gets warmer to install my real stuff, but what exactly is happening here-
The port hole i added a long time ago, the whole wall has fallen off so now i got 1 port with low tuning and a hole(length, thickness of MDF, 0.75") that is really high tuned.
When i play music, remarkably, i get incredible low bass response, very low, yet i am still able to pick up the higher frequencies also.
I know you can build a bandpass box like this to cover a wider range of frequencies but it takes up a lot more space.
What i am wondering is, what is happening to the sub itself? Would 2 diff tuned ports cause distortion more?
Would this setup be considered like a bandpass box just in terms of wider port tunings capability?
Also, just a little quick question-
When building a bandpass box, if its a 6th order, lets say for 1 sub, if both the front and the back port is tuned to the same frequency, is that known as the 1 note box whereas it will be X-tremely loud at that 1 note?
posted
I know about them accident boxes, its funny because i made a 1.75 cubic foot ported box....yes very small for a pair of DD 12's....with a port that was 5 by 10....kinda nuts no....yet it played 35-30 HZ at 148+ DB.....very unusual and did not make sense a tall to me, yet it played. No high response at all, just ultra low, crazy. I was powering the woofers with a MMATS D300HC each at the time...lotsa watts.
Posts: 841 | From: Pennsylvania | Registered: Feb 2002
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posted
Two different ports are not going to make it have two tuning frequencies. They are going to sum together, in some ghetto way, to make one tuning frequency.
-------------------- $20 Xtant 15's 9 cubic foot box at 45 hertz MTX 81000d at 1 ohm 144.76 decibels on Termlab Posts: 336 | From: Houston | Registered: Jun 2003
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posted
i love the technical response, "some ghetto way", hehe.
Well, hmm.
If thats true, i know the more ports u got the less air speed.
So... lets say that u tuned VERY low, like 25 hz, then made a lot of ports, lets say like 5 or 7 more that are only like 1-2" in depth, if the sum came out to be like 35-45 Hz, i think that would be interesting cuz the other 5-7 ports are taking up virtually no space especially if there was no wall for em......
Room for new box idea..... Bigger Vb yet low Mach and lows....
posted
The ports won't "combine", the hole will just act like...well...a hole. The sub will "see" a huge air leak in the box, not an actual port at all. Also, bandpass boxes are not made in this way. Two ports with two different lengths do not work (in the same enclosure).
-------------------- 1994 Ford F-250 7.3L Powerstroke Diesel Super Cab Long Bed 33" Mud Terrains Yeah, it's big, and yeah, it's got balls. Posts: 876 | From: Decatur, IN | Registered: Apr 2002
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