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New member Username: AudioplusUSA Post Number: 1 Registered: Nov-04 | Im in the process of build a single ported box for a 12" Brammah. Does anyone have any info ton tuning the elcosure to a certian freq. like 32hz or 28hz. thanks, Matt |
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New member Username: Rds11Louisville, Kentucky Post Number: 8 Registered: Nov-04 | the Adire Audio website says to tune a ported box for a 12" Brahma to 30 Hz |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 5515 Registered: Dec-03 | tuning ports is based on the length, and diameter of the port based on net enclosure volume. there are calculators on www.bcae1.com and www.the12volt.com |
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Bronze Member Username: BlownrivOH USA Post Number: 33 Registered: Nov-04 | calcuations are good for getting close, but there are always variable in the woofer and/or box that will through calculations off a little bit. the method i use is getting the port close to what you want with calculations, then playing test tones in the tuning frequency range to zero in. using a wave generator or test disc at consistant volume level, watch the cone excursion of the sub. cone motion will almost completely stop at the exact tuning frequency (Fb) of the system. if you're tuned too low, make the vent a little shorter. if you're too high, use a longer length. you don't always need to be exact, but remember that the lower your tuning frequency, the more difference being off by 1 or 2Hz can make. |
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Gold Member Username: GlasswolfNorthWest, Michigan USA Post Number: 5566 Registered: Dec-03 | it's even easier if you have a 1/3 octace RTA and a tone generator. most people don't have either one though. nor the $2k or so to buy the stuff.. lol |
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New member Username: AudioplusUSA Post Number: 4 Registered: Nov-04 | What is a good test cd and are there any i could download off the net? i got bass mekanic 5.0 but i dont think it has what you are talking about on it. |
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Bronze Member Username: BlownrivOH USA Post Number: 34 Registered: Nov-04 | i use bass mechanik - quad maximus. it has a sine sweep track, plus 10Hz-100Hz tones in 1Hz steps. i also use bass mechanik - power tools. it has even more test tones and a greater range of frequencies. still, i use quad maximus more often because it's easier to use, imo. i've never used 5.0, so i don't know. |