Closed End Transmission Line

[planet10]

There are golden ratio enclosures in your site.

My miniOnken tuning in an approximately 0.618:1:1.618 ratio rectangle. I lik eth eshape and they are easier to build than th erectangular or trapezoidal miniOnken. The alignment tends to yield smallish boxes. With the smaller drivers, the driver can be mounted on any of 5 sides. A pr for the Alpair 7.3 recently made in the UK with the drivers on the narrow side (my personal preference is on th ewide side with driver placed using the golden ratio again.

dave

 

[slmnklyc]

Net volume [Vb] determines how much output it will have and its length the tuning, so reduce Vb reduces available [mid] bass output and in general a TL's Vb needs to be anywhere from 4-10x Vas to get good bass output, so if you start at a closed point and need a 100" line, then the driver baffle area at the open end will be whatever is necessary to get the desired Vb.

IOW, if you make a TL's Vb = required for AS, then better overall to just make an AS box.

GM

Thanks For giving approximate numbers.Are these your own experiments?Just I am wondering..If you have any experience share with us..
I also think Using 1Vas Volume For box.I really don't want to obtain normally one Driver can produce..If Fs=64hz I only want to Reach 64hz, not 50hz or 30hz..It is just my opinion..
Even I think Using air suspension Volume and closed tapered TL(Maybe this can give benefit to air suspension enclosure,maybe it is meaningless??)

 

[GM]

Yes, not much in the way of TL/horn design I haven't tried and posted quite a lot over the years here and other forums.

Right, you can tune it to whatever you want and a quick sim in HR shows peak LF power when tuned to 64 Hz = 10x Vas with 4x Vas = ~70 Hz, 1x Vas = ~85 Hz and AS Vb = ~AS tuning, so TL line only adds unnecessary pipe harmonics that will need extra damping.

Classic sealed alignment = ~29.17 L/100 Hz Fc = ~AS tuning, so looks like 4x Vas would be minimum to maybe make it worthwhile, but all things considered, a simple AS box is sufficient and if you want a spiral for cosmetic reasons, just make it whatever length looks good to you and the equivalent AS amount of stuffing should be sufficient also.

GM