You can test your setups bass drop out. Mine active 8" bass reflex drops out at 33hz.
Just put it at 100hz on moderate volume and start sliding it to the left:
Online Tone Generator - generate pure tones of any frequency
Just put it at 100hz on moderate volume and start sliding it to the left:
Online Tone Generator - generate pure tones of any frequency
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DJK's notes in this thread https://forum.speakerplans.com/don-keeles-vented-box-formulas_topic41578.html#top
how about this for a modest assisted B6 sub? is there something better suited in the same price range? https://www.parts-express.com/pedocs/specs/295-434--dayton-audio-ds315-8-specifications.pdf
Resonant Frequency (Fs)24.2 Hz
DC Resistance (Re)6.1 ohms
Voice Coil Inductance (Le)1.43 mH
Mechanical Q (Qms)1.79
Electromagnetic Q (Qes)0.37
Total Q (Qts)0.31
Compliance Equivalent Volume (Vas)5.62 ft.³
Mechanical Compliance of Suspension (Cms)0.44 mm/N
BL Product (BL)15.6 Tm
Diaphragm Mass Inc. Airload (Mms)97.4g
Maximum Linear Excursion (Xmax)5.5 mm
Surface Area of Cone (Sd)506.7 cm²
Materials of Construction
Resonant Frequency (Fs)24.2 Hz
DC Resistance (Re)6.1 ohms
Voice Coil Inductance (Le)1.43 mH
Mechanical Q (Qms)1.79
Electromagnetic Q (Qes)0.37
Total Q (Qts)0.31
Compliance Equivalent Volume (Vas)5.62 ft.³
Mechanical Compliance of Suspension (Cms)0.44 mm/N
BL Product (BL)15.6 Tm
Diaphragm Mass Inc. Airload (Mms)97.4g
Maximum Linear Excursion (Xmax)5.5 mm
Surface Area of Cone (Sd)506.7 cm²
Materials of Construction
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hmmm - I've a pair of PE 15" trap cabinets and 15PZB40 - maybe an Interface B eq box . Make a little 3-way with 6.5" Eminence closed back midrange on a JBL waveguide (?) 0.4* 15pzb40's vas = 45.3 liter. PE says their 15" trap box is 2.75 cubic foot. woofer, vent and horn would eat up some of that space. Can I get a useful vent in it with the horn?
http://i.imgur.com/rJUXa82.jpg
midrange response 6.5" + WG with cap hghpass - would a 2nd order filter be better than
the 12uF cap?
- could go 2-way with DE250 and QSC waveguide
http://i.imgur.com/rJUXa82.jpg
midrange response 6.5" + WG with cap hghpass - would a 2nd order filter be better than
the 12uF cap?
- could go 2-way with DE250 and QSC waveguide
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If you're using more bass than your room, you gotta damage your ear drums and the people around you. If you wanna use those large drivers in the name of recording, accept the fact that they will not sound as good as expected. In recording, everything should be balance.
File: 18FH500.bb6
-----------------------------------------
Driver Properties
Name: 18FH500
Type: Standard one-way driver
Company: Faital Pro
No. of Drivers = 1
Fs = 30 Hz
Qms = 12.5
Vas = 374.8 liters
Cms = 0.205 mm/N
Mms = 137.1 g
Rms = 2.068 kg/s
Xmax = 9.25 mm
Xmech = 13.88 mm
P-Dia = 380 mm
Sd = 1134 sq.cm
P-Vd = 1.049 liters
Qes = 0.36
Re = 5.1 ohms
Le = 1.35 mH
Z = 8 ohms
BL = 19.14 Tm
Pe = 600 watts
Qts = 0.35
no = 2.71 %
1-W SPL = 96.48 dB
2.83-V SPL = 98.43 dB
-----------------------------------------
Box Properties
Name:
Type: Vented Box w/ Active HP Filter
Shape: Prism, square
Vb = 7 cu.ft
Fb = 27 Hz
QL = 5.828
F3 = 26.93 Hz
Fill = minimal
No. of Vents = 3
Vent shape = round
Vent ends = one flush
Dv = 4 in
Lv = 15.44 in
-----------------------------------------
Active 12 dB/oct. HP Filter
Fx = 27 Hz
Qx = 2
I did the ports with for a standard 4" (100mm) PVC pipe, others are possible.
-----------------------------------------
Driver Properties
Name: 18FH500
Type: Standard one-way driver
Company: Faital Pro
No. of Drivers = 1
Fs = 30 Hz
Qms = 12.5
Vas = 374.8 liters
Cms = 0.205 mm/N
Mms = 137.1 g
Rms = 2.068 kg/s
Xmax = 9.25 mm
Xmech = 13.88 mm
P-Dia = 380 mm
Sd = 1134 sq.cm
P-Vd = 1.049 liters
Qes = 0.36
Re = 5.1 ohms
Le = 1.35 mH
Z = 8 ohms
BL = 19.14 Tm
Pe = 600 watts
Qts = 0.35
no = 2.71 %
1-W SPL = 96.48 dB
2.83-V SPL = 98.43 dB
-----------------------------------------
Box Properties
Name:
Type: Vented Box w/ Active HP Filter
Shape: Prism, square
Vb = 7 cu.ft
Fb = 27 Hz
QL = 5.828
F3 = 26.93 Hz
Fill = minimal
No. of Vents = 3
Vent shape = round
Vent ends = one flush
Dv = 4 in
Lv = 15.44 in
-----------------------------------------
Active 12 dB/oct. HP Filter
Fx = 27 Hz
Qx = 2
I did the ports with for a standard 4" (100mm) PVC pipe, others are possible.
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Yes, when the bass horn's mouth area [or both combined if stereo] IS the sound wall. For drivers, you're ~ limited to a 1 WL max spacing of the XO point, so make the XO point low for largest flat area array; otherwise let peak SPL at vanishingly low distortion set the driver choice, manifold array design parameters.
GM
The upside of the BMS is that it has shorting rings, for lower harmonic distortion. This is very apparent in a box that is not horn loaded. A quality horn load will limit harmonics via bandpass. The BMS will sound noticeably cleaner in both the subs, and in the vocals, than those drivers without the shorting rings. The vocals bit is because the driver will be more sensitive in the band outside of which you are using it, and thus the harmonics will be too.
I don't understand this comment. I also see some pushback on it in other comments.
It might just be the "deep bass" portion. Are you talking about getting down to 10hz or 20hz? Because the OP is wanting to get to 40hz. It seems to me that this driver is easily going to do this. What am I missing? I don't want to say you are wrong, only want to make sure we are all discussing the same thing.
Q in
Which raises the non-rhetorical question: why would anybody want anything less than the lowest possible Q in their system... no matter what your sim may command you?
B.
I assume that's a rhetorical question since nobody I know thinks it is smart to maul your damping factor.
Which raises the non-rhetorical question: why would anybody want anything less than the lowest possible Q in their system... no matter what your sim may command you?
B.
So how does this all work?
I'm getting funny numbers.
The Qts of my speaker is .30 Which is good I think.
So 0.30^2 = 0.090
Fs isn't given.
Fr is, and that is 18Hz so 18^3=5832.
Vas is 151dm^3
voice coil length of 18mm.
I'm not really sure how to calculate when
I don't have the specific numbers though.
Then the dreaded Qms of a high 8.80???
Ouch.
Bummer.
And I'm still trying to follow along but
it way over my head.
So when we have two drivers in push-push, do we
divide or multiply the resulting calculations by 2?
The numbers are for the Eton 581/50 HEX driver
for living spaces. I don't see much about them
nor much written up.
cheers,
I'm getting funny numbers.
The Qts of my speaker is .30 Which is good I think.
So 0.30^2 = 0.090
Fs isn't given.
Fr is, and that is 18Hz so 18^3=5832.
Vas is 151dm^3
voice coil length of 18mm.
I'm not really sure how to calculate when
I don't have the specific numbers though.
Then the dreaded Qms of a high 8.80???
Ouch.
Bummer.
And I'm still trying to follow along but
it way over my head.
So when we have two drivers in push-push, do we
divide or multiply the resulting calculations by 2?
The numbers are for the Eton 581/50 HEX driver
for living spaces. I don't see much about them
nor much written up.
cheers,
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For sealed & reflex boxes you only need Qts, Vas, and Fs
Makes little difference unless you ar eusing a current amp.
2 drivers volume increases by 2, ports x2. Some numbers double, some halve, some stay the same.
A 55 litre vented box looks good. Tuning depending on how much room gain you have.
dave
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