Hi Oliver,
Sorry for the late reply - your post got by me somehow.
I haven't changed and retested yet. The box is sitting in the garage, taking up space. It's still in its foam-taped state, S1 remains @ 1.0 with the curved baffle entrance. I still need to take out the baffle, cut out the opening (leaving 1/4 of the circle UN-cut per Djim's suggestion) and retest. Then take out the angled board (from S1 to S2) and retest again.
One reservation I have: my drivers have an Fs of 35Hz and it was suggested to me to use them in TH enclosures tuned to the driver's Fs or 1-2Hz higher. The 5Fold/6Section cab has a tuning lower than the Fs of the drivers I have by a couple Hz.
Hi Eric,
I was just getting curious last night as to how the T/S parameters would look after being loaded into a cab...and again what they would look like after getting worked for some hours. Does heat cause fs to change as well? I'd like to buy a woofer tester some time to experiment.
Is it possible to convert this TH to a symmetrical layout? How much larger would it be?
I was just getting curious last night as to how the T/S parameters would look after being loaded into a cab...and again what they would look like after getting worked for some hours. Does heat cause fs to change as well? I'd like to buy a woofer tester some time to experiment.
Is it possible to convert this TH to a symmetrical layout? How much larger would it be?
fs (free air resonance) over time can change du to mechanical fatique
dont realy know how much,but can imagine that cheap drivers or stressed drivers suffer more.(fs should only go down)
heat can change parameters signifantly ,but should not change fs.
(please someone correct me if i'm wrong)
theoreticly i would ad 50~75 ltr extra for a symetric layout.
dont realy know how much,but can imagine that cheap drivers or stressed drivers suffer more.(fs should only go down)
heat can change parameters signifantly ,but should not change fs.
(please someone correct me if i'm wrong)
theoreticly i would ad 50~75 ltr extra for a symetric layout.
Hi Epa,
Change your suspension values slightly and see for yourself
Why do you think that pro pa manufacturers (including Danley) don't use their drivers below their Fs when high level signals are involved?
Some car speakers are mechanically compensated for deliberate use below their Fs to obtain high excursion in a relative 'easy' way. However, it does affect SQ one way or another.
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hi jimHi Epa,
Change your suspension values slightly and see for yourself
Why do you think that pro pa manufacturers (including Danley) don't use their drivers below their Fs when high level signals are involved?
Some car speakers are mechanically compensated for deliberate use below their Fs to obtain high excursion in a relative 'easy' way. However, it does affect SQ one way or another.
i honestly don't know
i tought that free air resonance is a pure mechanical /mass figure?
take the danly 221 tuned to an f3 of 22hz ,the b&c 21 sw152 has a fs off 32 hz
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Hi Eric,
If you look at the impedance plot of the TH221 you can see the minimum excursion is around the Fs of the driver, meaning the excursion maximum is above the Fs of the driver. And even it is designed optimal in my view, in the specs you can see the power rating is adjusted slightly downwards, to keep some (mechanical) reserves I guess. Also the dual driver settings give a small mechanical advantage.
Like I told Crescendo a while ago, if he serious wants to go to below 30Hz, I think he should look for some serious 21" drivers. If he wants low 30ties and still with enough output reserves, I would consider dual 18"settings for TH's.
If you look at the impedance plot of the TH221 you can see the minimum excursion is around the Fs of the driver, meaning the excursion maximum is above the Fs of the driver. And even it is designed optimal in my view, in the specs you can see the power rating is adjusted slightly downwards, to keep some (mechanical) reserves I guess. Also the dual driver settings give a small mechanical advantage.
Like I told Crescendo a while ago, if he serious wants to go to below 30Hz, I think he should look for some serious 21" drivers. If he wants low 30ties and still with enough output reserves, I would consider dual 18"settings for TH's.
Even I haven't seen any Klippel measurements of B&C drivers, when you compare the SW series with the NW series from paper, you can see that the SW series has more mass and lower mechanical losses. In other words, it looks like the SW series is more optimised for stronger mechanical forces (a similar difference you can see in the 9000 series from 18Sound, like you already know .
.
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B&C 18SW100:
Attachments
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B&C 18SW100 Klippel Analyzer BL curve p. 24.png -
B&C 18SW100 Klippel Analyzer mech stiffness of susp Kms curve p. 24.png -
B&C 18SW100 Klippel Analyzer BL symmetry range curve p. 25.png -
B&C 18SW100 Klippel Analyzer Kms symmetry range curve p. 25.png -
B&C 18SW100 Klippel Analyzer L(X) curve p. 25.png -
B&C 18SW100 Soundcheck Response & Harmonics p. 27.png -
B&C 18SW100 Soundcheck Distortion Plot p. 27.png
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