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Titan 48/Tuba 30 horn length.
Posted: Fri Feb 20, 2015 7:40 am
by AcousticScience
Why does the Titan 48, despite actually having a slightly longer horn than the Tuba 30, employ a higher high pass setting?
I read in the archives somewhere about the T48 having about 9 feet and the T30 8.something.
Re: Titan 48/Tuba 30 horn length.
Posted: Fri Feb 20, 2015 1:52 pm
by sine143
the very first part of the horn in the t30 is a bit of an odditty. I would attribute it something to more of a large throat chamber than the actual first segment of the horn.
Adding volume to a front chamber usually helps push the low corner down a lil bit, at the expense of upper bandwidth around 200hz (out of passband).
it also employs a bit of negative expansion after the throat chamber. that, coupled with the large rear chamber, and the 12" driver are likely what push it a bit lower than the t48 (as far as hipass is concerned).
Re: Titan 48/Tuba 30 horn length.
Posted: Fri Feb 20, 2015 4:23 pm
by Grant Bunter
It's not just the T30.
The T30, T45, and T60 all go lower.
The T48 and T39 go louder.
This suggests to me that the two different design types are about a trade off between sensitivity and content...
Re: Titan 48/Tuba 30 horn length.
Posted: Fri Feb 20, 2015 4:54 pm
by Bill Fitzmaurice
Grant Bunter wrote:
This suggests to me that the two different design types are about a trade off between sensitivity and content...
+1. THT is at the other end of the scale, trading sensitivity for maximum extension.
Re: Titan 48/Tuba 30 horn length.
Posted: Tue Feb 24, 2015 5:13 pm
by AcousticScience
sine143 wrote:the very first part of the horn in the t30 is a bit of an oddity. I would attribute it something to more of a large throat chamber than the actual first segment of the horn.
What I understand from this is that because the first segment is slightly wider, it adopts some 4th order bandpass quantities..
Also from my own hornresp tinkering, I find horns with a greater expansion rate need to be slightly longer for the same Fc - the Titan having a faster expansion rate compared to the Tuba 30 having a slow expansion rate until the very end, (although the end is possibly optimised for V-Plate correction).
Re: Titan 48/Tuba 30 horn length.
Posted: Tue Feb 24, 2015 7:10 pm
by sine143
you are correct in your assumption that faster flare will result in higher fc than slower flare (and subsequently smaller mouth) for a horn the same length.
However, the horn with the faster flare has more volume, and more sensitivity.