TH-18 Flat to 35hz! (Xoc1's design)

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#3,245
but if you are not doing EDM/RAVE festival type outdoors events, you do not really need that low for PA

from own experience i know how 50Hz "sub" cabinets "sound", versus double 18's Bass Reflex 30hz cabinets "sound"
i agree with BP1
i think 50Hz must be called Bass cabinet not Sub cabinet, sub must be 35hz and below

last sunday i run sound for a live band , dance floor was for around 50 people max
with a pair of DSR112's (high pass around 120Hx ) and a pair of yorkville BASS cabinets ( LS608's) driven
by a bridged XLS2500 , i was able to get a nice mix from 40feet away.
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the bass cabinets was high passed @50hz ( per yorkville specs)
and people were all happy dancing all over texmex music

is it true that you do not really need cabinets that can get to 30hz for PA live music,
as
every octave lower you go you will need 4x XMAX to maintain the same SPL.
that means much expensive drivers or bigger cabinet count as going lower will yield less SPL
so you will need more cabs and amps to compensate the loss of SPL because the lower Fs.

and BTW i am eager to make 4 of these,
just one cab will wipe the floor off the 2 old yorkies
( double 15's TH cabs designed by Art Welter)
called the B Lowrider cabinet
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i updated the drawing and added 2 drivers inside
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#3,249
Hello guys!
Please don't stone me, but what is the official Hornresp input mask for this project?

In the course of this very long thread, so much philosophizing, experimentation and alternative stuff was posted. I really don't understand some of it.
It would be really nice if the developer of this project (@Xoc1) could tell me what the current state of things is!

Kind regards
 
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#3,251
lineup said:
Here is a bass recording:

Click to expand...
After performing a spectral analysis using Audacity on a large subsection of the audio from the above track, the results are plotted below. This track has significant low-frequency energy between 21Hz and 80Hz. It's interesting how there are three quite distinct, narrow peaks at 16Hz, 18Hz, and 19Hz, and a much broader peak at 25Hz or so. A very long FFT length was needed to resolve them.

1742325969619.png
 
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#3,254
tigeranand said:
I have a SB Audience BIANCO-18SW450 18" Subwoofer can someone give a box design for this driver.
Click to expand...
I plugged the BAINCO-SW450's Thiele–Small parameters into VituixCAD. It seems that this driver can have a quite extended bass response in a 500-litre vented-box enclosure tuned to 26.0Hz. The −3dB low-frequency cut-off point is a quite low 25.2Hz. it can produce around 117dB SPL for 120W re 8Ω, only exceeding its linear Xmax below about 20Hz. It is highly recommended that an infrasonic filter be applied in the interests of driver protection.

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Adding a 2nd-order 22Hz Butterworth high-pass filter produces much reduced infrasonic driver cone excursion, while only raising the subwoofer's cut-off frequency by 1.3Hz. The results are shown below.

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A 230-litre closed-box enclosure with a high-pass peaking filter and a low-pass filter in action produces the following simulated response.

1743107507852.png
 
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#3,256
An 8th-order low-pass filter, such as the one simulated, to tame all those highly-excitable upper-frequency resonances seems to be a real necessity. A little bit of EQ in the dip between the two SPL peaks would flatten the response by about 3dB. A closed-box or a vented-box system seems to be much easier to implement, but if a maximum SPL output capability is needed, then the tapped-horn enclosure seems to be able to supply it quite well.
 
#3,258
witwald said:
An 8th-order low-pass filter, such as the one simulated, to tame all those highly-excitable upper-frequency resonances seems to be a real necessity. A little bit of EQ in the dip between the two SPL peaks would flatten the response by about 3dB. A closed-box or a vented-box system seems to be much easier to implement, but if a maximum SPL output capability is needed, then the tapped-horn enclosure seems to be able to supply it quite well.
Click to expand...

Check the thread below. He only uses PEQ and no high or lowpass filters (which is basically the same principle in my book).

G

Thread 'So i impulse bought a sub. What would you do with it?'

Yeah so i bought a sub on a whim. Its a skar vxf 15 d4.
T/S Parameters
Bl 39.1 n/a
Fs 35.4 Hz
Re Dual 4 Ω
Sd 779.3 cm2
Cms 0.05 mm/N
Mms 384.3 gr
Qes 0.43
Qms 4.78
Qts 0.40
Vas 47.7 L
Nref 0.47%
Xmax 30 mm (one-way)
Sensitvity
88.7 dB
I plan on attempting to build an hroar box for it. So far i have modeled it in a roar box with very nice response from 26hz-80hz. I havent figured out how to translate bp8s function in hornresp to hroar, but i have a good idea what will work without modeling it. Ill post a hornresp response later today. I really have no particular need for this, i just want...
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