Titan 48/Tuba 30 horn length.

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AcousticScience
Posts: 148
Joined: Tue Jan 20, 2015 4:37 pm

Titan 48/Tuba 30 horn length.

#1 Post 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.

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: Titan 48/Tuba 30 horn length.

#2 Post 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).
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

Grant Bunter
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Location: Ilfracombe Queensland Australia
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Re: Titan 48/Tuba 30 horn length.

#3 Post 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...
Built:
DR 250: x 2 melded array, 2x CD horn, March 2012 plans.
T39's: 4 x 20" KL3010LF , 2 x 28" 3012LF.
WH8: x 6 with melded array wired series/parallel.
Bunter's Audio and Lighting "like"s would be most appreciated...

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Bill Fitzmaurice
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Re: Titan 48/Tuba 30 horn length.

#4 Post 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.

AcousticScience
Posts: 148
Joined: Tue Jan 20, 2015 4:37 pm

Re: Titan 48/Tuba 30 horn length.

#5 Post 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).
Attachments
Tuba.jpg

sine143
Posts: 3066
Joined: Sat Feb 06, 2010 3:27 pm
Location: Raleigh NC

Re: Titan 48/Tuba 30 horn length.

#6 Post 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.
Built:
2x Tuba 30s delta12lf loaded (gone)
4x Otop12 d2512 loaded
8x t48s (18, 18, 24, 24, 30, 30) 3015lf loaded
2x AT (1 mcm, 1 gto 804)
2x SLA Pro (dayton pa6, 6 goldwood piezo loaded)
1x bastard XF208

2x OT212 (delta pro 450a loaded, eminence psd)

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