Good HZ for a Ported Box
Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=35037
Printed Date: May 13, 2024 at 10:04 PM
Topic: Good HZ for a Ported Box
Posted By: JustDoIt2
Subject: Good HZ for a Ported Box
Date Posted: July 04, 2004 at 2:31 PM
HI, Im building a box, Ported box for my subs (2 12" Kove argamedon) and I was wandering What is a good HZ to tunned the box, I was thinging like 36HZ. What do you guys think?
Replies:
Posted By: JustDoIt2
Date Posted: July 04, 2004 at 2:45 PM
Oh these are the specs of my subs *Power Handling: 800 watts RMS *VCdia: 3" *Le: 2.5 mH *Nominal impedance: 4 ohms per coil *Re: 3.0 ohms *Frequency response: 20-300 Hz. *Magnet weight: 192 oz. *Fs: 34 Hz *SPL: 90 dB 2.83V/1m *Vas: 1.2 cu. ft. *Qms: 5.33 *Qes: .39 *Qts: .36 *Xmax: 18 mm *Dimensions: Overall Diameter: 12-1/2", Cutout Diameter: 11", Mounting Depth: 6-3/4", Magnet Diameter: 8", Magnet Height: 3-1/8 the box is 2.56 ft^3 per chamber - .15 ft^3 port displacement - .16 ft^3 driver displacement = 2.25 ft^3 net internal volume if I tuned to 36hz the port will be 13" X 1 1/4" X 11 9/16" SO i dont know if 36hz if a good HZ to port my box the amp is 1100 W RMS at 1 ohm
Posted By: DYohn
Date Posted: July 04, 2004 at 3:35 PM
Posted By: JustDoIt2
Date Posted: July 04, 2004 at 5:30 PM
Thanks for the Info. but in your opinion 36HZ will a be a good frequenzy ??
Posted By: stevdart
Date Posted: July 04, 2004 at 6:19 PM
Kove lists their port and enclosure specs here. ------------- Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.
Posted By: JustDoIt2
Date Posted: July 04, 2004 at 6:27 PM
Yes i know, but i dont have the model number i just know they are the argamedon but dont have model number, Thats why i was asking if 36hz was a good HZ to tunning my box
Posted By: Marshallmadman
Date Posted: July 04, 2004 at 9:35 PM
It might be helpful if you told us what you are looking to get from these subs. What kind of music do you listen to? Are you going to be utilizing a subsonic filter? If so, how many db/octave is it? Etc., etc.....
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I'm just a regular guy. I don't know why all the fuss about me....
Posted By: JustDoIt2
Date Posted: July 04, 2004 at 10:35 PM
Yes I will use a subzonic filter. to the lower HZ which is think it is 20hz the amp is the menphis 1 ohm,,i cant remember the model i listen to rap reggae, that kind of music..
Posted By: DYohn
Date Posted: July 05, 2004 at 9:58 AM
From subwoofer DIY website, here are the formulas for calculating tuning frequency (Fb) in a ported enclosure. To determine the optimum box size and tuning for a ported enclosure system, you will need to know the following Theile/Small parameters for the driver: Vas = Equivalent air compliance (litres) Qts = total Q of the driver at its resonant frequency Fs = resonance frequency of the driver (Hz) Dv = internal diameter of port (cm) then, Vb = 20*Qts^3.3*Vas Fb = (Vas/Vb)^0.31*Fs F3 = (Vas/Vb)^0.44*Fs dBpeak = 20*LOG(Qts*(Vas/Vb)^0.3/0.4) where, Vb = net box volume (litres) Fb = box resonant frequency (Hz) F3 = -3dB frequency (Hz) dBpeak = maximum peak or dip in system response ------------- Support the12volt.com
Posted By: Marshallmadman
Date Posted: July 05, 2004 at 10:23 AM
You might want to consider running your subsonic at more like 40hz. That's just my opinion. You've got some really good speakers there. Kudos to you for putting forth the effort to make sure you get the most out of them.
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I'm just a regular guy. I don't know why all the fuss about me....
Posted By: DYohn
Date Posted: July 05, 2004 at 10:50 AM
The "subsonic" filter should be set just below Fb in a ported enclosure. If it is set above Fb, you will never achieve max SPL from the enclosure. You do not want to drive a woofer too hard below Fb, however, as the speaker is unloaded below that frequency and is basically running in free-air. If your enclosure is tuned to 36 Hz, the "subsonic" filter should be at least 18db/octave and set around 30Hz, in my opinion. ------------- Support the12volt.com
Posted By: forbidden
Date Posted: July 05, 2004 at 7:42 PM
Which I will agree with as usual and add to it that 36hz is a great tuning frequency, for that matter so is 31.75 and you will probably never be able to hear the difference as it is less than 1/2 octave down in frequency. A noticeable difference in tuning frequencies for the most part (not all the time) will come when you are tuning by a full octave in bandwidth. So if you a tuning point of 36hz, a new tuning point of 18hz would be one full octave down and produce a noticeable difference provided the amp can provide the current to drive the sub with enough amplitude for you to hear it.
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Posted By: JustDoIt2
Date Posted: July 05, 2004 at 11:11 PM
ok, thank you to all you .. I got the idea. thanks
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