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Old 30th May 2006, 09:58 PM   #1
jwatts is offline jwatts  United States
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Default Bandpass Question

I am having a difficult time designing a bandpass box because the ports are to long and won’t fit inside the enclosure. My question is this. If I can preserve the front and back enclosure volume ratios can I simple multiply both by a factor and make them larger. The enclosure is a 4th order bandpass.

Example.

Assume was originally calculated to be.

Vf=.3ft^3
Vr=.5ft^3

Can I simply multiply both Vf and Vr by 3 and not change my passband, ripple, and Fb for the enclosure.
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Old 30th May 2006, 11:23 PM   #2
lndm is offline lndm  Australia
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To make a vent shorter, you could make it narrower. Still, try to keep it as wide as possible. A really long vent can cause resonance problems anyway.

Have you considered mounting the vent outside the box?
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Old 30th May 2006, 11:31 PM   #3
jwatts is offline jwatts  United States
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Default Impractical

My current application will not allow me to vent outside of the enclosure.
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Old 31st May 2006, 12:18 AM   #4
Ron E is offline Ron E  United States
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Default Re: Bandpass Question

Quote:
Originally posted by jwatts
Can I simply multiply both Vf and Vr by 3 and not change my passband, ripple, and Fb for the enclosure.
No. Use a PR.
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Old 31st May 2006, 12:25 AM   #5
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Is there any possibility of bending the ports inside the enclosure?If you use plasitc pipe the purchase of 90 degree joints etc is v.easy.
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Old 31st May 2006, 01:13 AM   #6
jwatts is offline jwatts  United States
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Default Pr

Does anybody have any experience using a PR in this type of application? If so does perform as well as a port.
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