Hi,
For a vented box with a specific tuning the real "vent air mass" is variable.
Its a poor choice of wording for the "effective inductance" of the port.
For a given "inductance" and hence tuning with the "capacitance" of
the box volume, the smaller the port CSA the shorter it is, the larger
the CSA the longer it, the minimum CSA being determined by the
maximum air velocities in the port, i.e. the onset of "chuffing".
rgds, sreten.
For a vented box with a specific tuning the real "vent air mass" is variable.
Its a poor choice of wording for the "effective inductance" of the port.
For a given "inductance" and hence tuning with the "capacitance" of
the box volume, the smaller the port CSA the shorter it is, the larger
the CSA the longer it, the minimum CSA being determined by the
maximum air velocities in the port, i.e. the onset of "chuffing".
rgds, sreten.
There was never question of any "vent inductance" or "port inductance". We better keep saying that the primary physical nature of a port (or vent) in a bass-reflex enclosure is the air mass contained into the vent, moving back and forth.
Why I am writing this ? Because :
- Thinking in terms of an air mass, one can easily visualize that the mass of the air moving back and forth may slightly differ from the value calculated by multiplying the vent volume by the air density, because of boundary effects. There is abundent litterature about this.
- One can easily visualize that there is a degree of freedom when designing the vent : for a given volume (or air mass) the vent can be long&narrow or short&wide. As a rule of thumb, one can select the "gold" ratio equal to 1.618 between the diameter and the lenght. There is abundent litterature about this.
- One can easily visualize that if by misluck, the vent air mass needs to be very small (for getting the tuning), there may be a problem when combining this small vent to a wide surface loudspeaker. At very low frequency and high SPL, there will be a disproportion between the big air volume displaced by the membrane moving back and forth, and the small vent needing to convey this air volume back and forth too. There is abundent litterature about this.
At this stage, I would like to keep the things simple and intuitve, however accurate about the physical principles.
- Physically, I would say that we need to keep an eye on the maximum air displacement the woofer is capable. This is equal to the woofer diameter multiplied by the woofer excursion. Take a 20 cm woofer able to move 4mm back and forth maximum. The woofer max displacement equals 0.125 litre. I think that it would be wise to have a vent having twice this volume hence 0.250 litre. This way, at max power at very low frequencies, half of the vent air will stay inside the port. This is a starting point. In order to refine, we need to check at various frequencies, for a given SPL profile. Remember that we may be lucky, as the woofer excursion naturally decreases when the frequency is raising, for a constant SPL.
- Physically, I would also say that if the port volume is not neglectible in front of the box volume, there may be an issue causing an asymetry. Remember that the vent is supposed to be a mass. A pure mass with no impact on compliance. Now, if the port volume is significant compared to the box volume, if there is a lot of air travelling into the port, the box may see a non neglectible air depletion when the vent is expelling air. This is equivalent to the vent adding an asymetric dynamic compliance. At the time of writing this, I remember experiments made 30 years ago on bass-reflex boxes yielding to the discovery of an "unexplainable" membrane offset at high SPL, and some loudspeaker producers compensating this by slightly offsetting the idle point of the membrane.
As a general conclusion I would say that nothing is constant in our world. For being able to realize the physical nature of the phenomenon, one must avoid putting intermediate abstractive layers.
This is why I love simulating the systems using LTspiceIV, including the crossovers (active or passive), the amplifiers, the drivers, the enclosures, the vents and the delays that may be caused by the mechanical misalignment of sound sources.
Why I am writing this ? Because :
- Thinking in terms of an air mass, one can easily visualize that the mass of the air moving back and forth may slightly differ from the value calculated by multiplying the vent volume by the air density, because of boundary effects. There is abundent litterature about this.
- One can easily visualize that there is a degree of freedom when designing the vent : for a given volume (or air mass) the vent can be long&narrow or short&wide. As a rule of thumb, one can select the "gold" ratio equal to 1.618 between the diameter and the lenght. There is abundent litterature about this.
- One can easily visualize that if by misluck, the vent air mass needs to be very small (for getting the tuning), there may be a problem when combining this small vent to a wide surface loudspeaker. At very low frequency and high SPL, there will be a disproportion between the big air volume displaced by the membrane moving back and forth, and the small vent needing to convey this air volume back and forth too. There is abundent litterature about this.
At this stage, I would like to keep the things simple and intuitve, however accurate about the physical principles.
- Physically, I would say that we need to keep an eye on the maximum air displacement the woofer is capable. This is equal to the woofer diameter multiplied by the woofer excursion. Take a 20 cm woofer able to move 4mm back and forth maximum. The woofer max displacement equals 0.125 litre. I think that it would be wise to have a vent having twice this volume hence 0.250 litre. This way, at max power at very low frequencies, half of the vent air will stay inside the port. This is a starting point. In order to refine, we need to check at various frequencies, for a given SPL profile. Remember that we may be lucky, as the woofer excursion naturally decreases when the frequency is raising, for a constant SPL.
- Physically, I would also say that if the port volume is not neglectible in front of the box volume, there may be an issue causing an asymetry. Remember that the vent is supposed to be a mass. A pure mass with no impact on compliance. Now, if the port volume is significant compared to the box volume, if there is a lot of air travelling into the port, the box may see a non neglectible air depletion when the vent is expelling air. This is equivalent to the vent adding an asymetric dynamic compliance. At the time of writing this, I remember experiments made 30 years ago on bass-reflex boxes yielding to the discovery of an "unexplainable" membrane offset at high SPL, and some loudspeaker producers compensating this by slightly offsetting the idle point of the membrane.
As a general conclusion I would say that nothing is constant in our world. For being able to realize the physical nature of the phenomenon, one must avoid putting intermediate abstractive layers.
This is why I love simulating the systems using LTspiceIV, including the crossovers (active or passive), the amplifiers, the drivers, the enclosures, the vents and the delays that may be caused by the mechanical misalignment of sound sources.
Hi,
No there isn't because the above is absurd. For a given box with a given
port tuning the only freedom is the port is short+narrow or long+wide.
e.g. a 10L box tuned to 50Hz, dia:length -
1.5cm:1cm, 2cm:2.25cm, 3cm:6.13cm, 4cm:12cm, 5cm:19.5cm.
Practically probably an ~ 4cm dia : 12cm long port would be used.
One port size suggested by those ratios is far too small, around
1.5cm dia : 1cm long, the other somewhat better at 2.5cm : 4cm.
But there is nothing special really about those ratios.
It is not the case the "air mass" / port volume is constant.
rgds, sreten.
Get a proper speaker simulator, after all they run on top of SPICE.
Checkout the free version of Basta! : http://www.tolvan.com/basta/
See the speaker modelling in the manual.
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hello, hello, are you absolutely sure that all the above dia:lenght combinations do provide a resonance at 50Hz into a 10L box ?
Hi,
Hello, Hello ? A lot more than the glaring fundamental error in your post.
No I'm not, I used WinISD and its not the most accurate program out there.
Arguing about the numbers is pointless if your going to ignore the principles.
The idea that for a 10L box tuned to 50Hz the port volume
is constant is so wrong your point above seems insulting.
For constant frequency as you increase the CSA of the port you must
increase the air mass of the port, i.e. make it longer, not shorter, that
it totally wrong, and obviously wrong from a physics perspective* and
any practical experience with loudspeakers, your completely wrong.
rgds, sreten.
*Hemholtz Resonance
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I have nothing against dedicated speaker simulation software. I've used tons of them before ending up using LTspiceIV.
LTspice is free. Using LTspiceIV, you face no limit regarding the design capabilities and output curves capabilities :
- Sum of systems for calculating the global response of multiway systems
- Cone excursion, Air velocity in the vent, Air excursion in the vent
- Arbitrary power amp topologies including conventional wideband voltage amplification, negative resistance drive, current drive, speed feedback and acceleration feedback
- Arbitrary DC-servo topologies like inverting and non-inverting
- Arbitrary active filters topologies
- Arbitrary passive filters topologies
- Arbitrary semi-feedback topologies like estimating the motional voltage and trying to drive the speaker using this voltage as feedback source
- Taking into account delays caused by the sources mechanical misalignment
As safety net, LTspiceIV enables you to plot the free-air impedance of the speaker, with and without the added mass. This enables you to compare your LTspiceIV driver model with the physical reality you are facing. If LTspiceIV is delivering different plots than what you just physically measured, you know you need to edit the parameters like the membrane mass, BL, compliance and so on, before trying to model the system.
From my experience, dedicated speaker simulators still have the edge regarding features and utilities like :
- pre-calculating the Baffle steps and room gain
- pre-calculating the Back wall reflection
- pre-calculating array effects like using 4 drivers or more (comb effect)
- pre-calculating polar radiation patterns
- ease of use for a 8th order passband subwoofer (because such equivalent schematic is far from trivial - I'm still in search of a good one)
- small utilities like splitting one vent into Multiple Vents
- optimizers for automatically calculating the box dimensions and vent size(s).
- optimizers for automatically calculating passive filters
- optimizers for automatically calculating active filters
- optimizers for automatically calculating equalizers like the Linkwitz 2nd-order bass shaper (usually known as the Linkwitz transform)
Today more enthusiasts want to access the physical layer that stays hidden behind the polished user interfaces of dedicated speaker simulation softwares. Let me put forward that LTspiceIV is a good teacher, in this particular context.
With some anticipation, I think that a bright future is to enable plugins into LTspiceIV. After entering the equivalent schematic, you would access a plugin menu and select one plugin. Like automatically calculating the box and the vents. Like running a set of simulations for getting all curves in one shot. Like exporting data using a specific format.
After tasting LTspiceIV as speaker modelization tool, you'll never assume that a 10L box can form a "xxHz resonance combined with a yy vent". Because you'll know that this proposition is a nonsense. There is one parameter missing. You need to specify the membrane surface. Physically, the vent is a mass which translates into a coil in the LTspice schematic. Frequency resonances occur because of capacitors represented in the LTspice schematic. There are two capacitors. One is the driver suspension compliance (in series). The other one is the equivalent box compliance (in parallel). And we know since ages that the box compliance depends on two parameters : the box volume and the membrane surface.
sreten, I have no idea from where you got the idea that a 1.5cm:1cm vent and a 5cm:19.5cm vent could resonate at the same frequency. This is nonsense, put this way. This is not going to help our friend buggsson.
sreten, if you feel that asking a "hello hello ..." question to you is an insult, then there must be many people insulting you everyday. Feel free to flag such insult and it could be your last.
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sreten, you can't ignore that everybody will agree that your proposition saying "a 1.5cm:1cm vent and a 5cm:19.5cm vent could resonate at the same frequency", is a nonsense taken word by word. Because everybody will agree there is something missing in the equation. Initially you provided a 10L box as additional element. But unfortunately according to me this is still not valid. Too bad. As non-agressive settlement proposition, let me conclude that you may be right in your head, but unfortunately, because you are not paying attention to the wording, because you are not bringing one positive element in the discussion, only bringing detrimental claims, you do clash. You asked for the clash. Look your offensive post ! Shame on you.
Everybody will agree that a 1.5cm:1cm vent and a 5cm:19.5cm vent could INDUCE a same resonance frequency, if the loudspeaker membrane surface and the box volume get modified accordingly. A 1.5cm:1cm bass port in a laptop computer induces a quite low resonance frequency, but in such case the driver is less than 1 inch tall ! There is the truth. Sorry.
Everybody will agree that a 1.5cm:1cm vent and a 5cm:19.5cm vent could INDUCE a same resonance frequency, if the loudspeaker membrane surface and the box volume get modified accordingly. A 1.5cm:1cm bass port in a laptop computer induces a quite low resonance frequency, but in such case the driver is less than 1 inch tall ! There is the truth. Sorry.
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More OT remarks and insults removed. Points given.Last warning. Keep it civil or enjoy a stay in the sin-bin.
1.
From the Helmholtz theory, we know that the resonant frequency, for a given box volume, is kept the same if multiplying the cross-section area (of the vent) by the same factor as the lenght (of the vent).
Helmholtz resonance - Wikipedia
There is thus freedom for designing the vent. Say there is a vent diameter and a vent lenght. The same resonant frequency will be acheived with the same box volume with a vent having a x1.41 diameter and a x0.50 lenght. Or with a vent having a x0.707 diameter and a x2.000 lenght. I can't disagree !
2.
From the LTspice schematic, we know that the vent effect is represented by an inductance wired next to the capacitor representing the box compliance.
3.
In the LTspice schematic, the capacitor representing the box compliance is function of the box volume and the driver membrane surface.
4.
The Helmholtz resonator described in 1) and the LTspiceIV schematic described in 2) are not directly compatible. A change of variable is needed. To give you an idea of the difference, the LTspiceIV schematic is basing on membrane speed. While sound is proportional to the acceleration of a moving surface. Need to multiply by the surface and the acceleration. In a Bass-Reflex, there are two output devices, with their own areas and accelerations : the driver membrane surface and the vent cross-section area. In the LTspice schematic, the value of the coil should not be equal to the physical air mass. There should be a scale factor dealing with the surface ratios.
5.
So practically, even if under LTspice for a given tuning the coil representing the vent effect needs to remain the same (for keeping the resonant frequency the same), the actual vent air mass can vary, depending on the vent cross-section area chosen by the designer. I thus agre with you, technically.
We need to remember that we are dealing with representations of the physical reality. We need to remember that we can't directly transpose from one representation to another representation. If you took 1 minute looking at the LTspice schematic you would have been able to explain this, maybe better than me.
From the Helmholtz theory, we know that the resonant frequency, for a given box volume, is kept the same if multiplying the cross-section area (of the vent) by the same factor as the lenght (of the vent).
Helmholtz resonance - Wikipedia
There is thus freedom for designing the vent. Say there is a vent diameter and a vent lenght. The same resonant frequency will be acheived with the same box volume with a vent having a x1.41 diameter and a x0.50 lenght. Or with a vent having a x0.707 diameter and a x2.000 lenght. I can't disagree !
2.
From the LTspice schematic, we know that the vent effect is represented by an inductance wired next to the capacitor representing the box compliance.
3.
In the LTspice schematic, the capacitor representing the box compliance is function of the box volume and the driver membrane surface.
4.
The Helmholtz resonator described in 1) and the LTspiceIV schematic described in 2) are not directly compatible. A change of variable is needed. To give you an idea of the difference, the LTspiceIV schematic is basing on membrane speed. While sound is proportional to the acceleration of a moving surface. Need to multiply by the surface and the acceleration. In a Bass-Reflex, there are two output devices, with their own areas and accelerations : the driver membrane surface and the vent cross-section area. In the LTspice schematic, the value of the coil should not be equal to the physical air mass. There should be a scale factor dealing with the surface ratios.
5.
So practically, even if under LTspice for a given tuning the coil representing the vent effect needs to remain the same (for keeping the resonant frequency the same), the actual vent air mass can vary, depending on the vent cross-section area chosen by the designer. I thus agre with you, technically.
We need to remember that we are dealing with representations of the physical reality. We need to remember that we can't directly transpose from one representation to another representation. If you took 1 minute looking at the LTspice schematic you would have been able to explain this, maybe better than me.
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I keep telling you that simply not true.
If you double the length f goes down by root2.
If you halve the CSA, f goes down by root2,
(If you half the diameter f goes down by half, an octave.)
Therefore if you 1/2 CSA and x2 length fvent will drop by an octave.
You've quoted an article you say agrees with you, but you have not checked
the equations. (How do you argue with someone who appears to do that ?)
The article does state or imply what you say it does.
As your first point is wrong so its your second. I've already illustrated
the correct degrees of freedom for designing the ports, and how you can
arrive at the two ratios previously mentioned, which in fact for fairly large
boxes and not too low tuning one of the two is usually a very usable size.
Helmholtz resonance - Wikipedia, the free encyclopedia
The final equation clearly shows for fixed frequency (A/L) or CSA/length
is constant, not CSAxlength, with all other parameters constant, but
this equation ignores the vent length corrections normally applied to
vents in boxes, so my previous numbers will not plug in correctly.
I still annoyed my posts were not taken at face value.
You've insisted your correct without ever checking.
I don't go round saying the following lightly :
rgds, sreten.
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Please note that in the above point 1 from post #91, I wrote :
You have not undertood that I am not 1/2 CSA and x2 length,
but instead I am x2 CSA and x2 length.
The other post you are referring with x1.41 and x0.50 is coming from another, older discussion with the context already explained dealing with the difficulty of getting "gold" proportions regarding the vents IF wanting to keep the mass the same, which actually is useless, I reckon.
Pay more attention next time. This is getting boring.
You feel annoyed because your posts were not taken at face value. Quite understandable : untill your last post (which is coming from the wikipedia page I was referring about the Helmholtz theory), there was no constructive info. If, from the beginning, you were explicitely referring to the Helmholtz law, the situation would have been nicer.
I'm would like to know if my LTspice modelization remains valid in the particular case when the membrane driver and the vent have the same area. In this particular case, as explained in point 4 of post #90, I think they can "share" the same capacitor representing the box compliance. Any advice welcome.
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Hi,
Yes I need to pay more attention, I missed that is statement 1.
Your right the first statement is correct, but the second does not follow
the first, I assumed what you were meaning to say meant the two
statements followed but they don't. So your disagreeing with yourself.
(I still assume you meant to say what you've been saying all along.)
I can and do disagree :
Compared to a 1 diameter 1 length :
x 1.41 diameter and x 0.5 length frequency goes up an octave.
x 0.707 diameter and x 2.0 length frequency goes down an octave.
This is getting boring if you actually claiming you meant statement 1)
but not statement 2), the latter is what you have been claiming all along.
Now you are saying the principle of 2) is useless, the same
air mass, but simply not admitting that 2) is simply wrong,
the same air mass with different ratios gives different f's.
And that your comments on my posts since I posted 81 are all wrong.
(Points 4+5 in post 90 is what post 81 says, TBH I did not get past 1.)
And that what I've been saying is consistently correct.
A 1.5cm dia 1cm long port will resonate at the same frequency
as a 5cm dia 19.5cm long port in any box, for 10L, at 50Hz.
(According to WinISD). Very easy to check for anyone.
I was not being constructive ? If you had bothered to spend
5 minutes playing with WinISD (or any other simulator except
your own) this sorry argument would have been unnecessary.
AFAIK the vent area makes no difference to the interaction
with the box "capacitor". Vent area = driver area is impractical.
rgds, sreten.
http://www.tolvan.com/basta/Basta!TechDoc.htm
Yes I need to pay more attention, I missed that is statement 1.
Your right the first statement is correct, but the second does not follow
the first, I assumed what you were meaning to say meant the two
statements followed but they don't. So your disagreeing with yourself.
(I still assume you meant to say what you've been saying all along.)
I can and do disagree :
Compared to a 1 diameter 1 length :
x 1.41 diameter and x 0.5 length frequency goes up an octave.
x 0.707 diameter and x 2.0 length frequency goes down an octave.
This is getting boring if you actually claiming you meant statement 1)
but not statement 2), the latter is what you have been claiming all along.
Now you are saying the principle of 2) is useless, the same
air mass, but simply not admitting that 2) is simply wrong,
the same air mass with different ratios gives different f's.
And that your comments on my posts since I posted 81 are all wrong.
(Points 4+5 in post 90 is what post 81 says, TBH I did not get past 1.)
And that what I've been saying is consistently correct.
A 1.5cm dia 1cm long port will resonate at the same frequency
as a 5cm dia 19.5cm long port in any box, for 10L, at 50Hz.
(According to WinISD). Very easy to check for anyone.
I was not being constructive ? If you had bothered to spend
5 minutes playing with WinISD (or any other simulator except
your own) this sorry argument would have been unnecessary.
AFAIK the vent area makes no difference to the interaction
with the box "capacitor". Vent area = driver area is impractical.
rgds, sreten.
http://www.tolvan.com/basta/Basta!TechDoc.htm
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Dear sreten, there is no need to repeat 1 billion times that I was wrong in thinking that in my LTspice simulation, the inductance was the direct representation of the vent air mass. You are harassing me. Let me put straight the whole thing once for all. I already explained in post #94 that I was wrong interpreting the modelization this way. I already explained in post #94 and following posts that I was wrong in assuming that the vent volume (hence air mass) needs to be kept constant for keeping the bass-reflex tuning the same. Some of your offensive posts towards me already went supressed by moderators. Are you planning to reissue them ? Don't try to victimize yourself. This would be dishonest now that your offensive posts got erased by the moderators. One important capability on a public forum, is to be able to understand the logic of the other party. I did the effort trying to understand your energic (to say the least) refutation logic. I did my homework. You delivered no single clue that your energic refutation logic was basing on the well known Helmholtz resonator law. I thus pointed the wikipedia page about the Helmholtz law, to tell you that finally I was understanding your point of view of me being wrong about the constant vent mass criterion. But still can't accept the impolite comments you did, now erased by the moderators.
Then in the next post I asked if you could advise on the apparent paradox, about the capacitor representing the box compliance, and the inductance "related" to the vent mass, with the idea that the value of this inductance is not fixed, but completely depending on the arbitrary shape and size of the vent. I then proposed as explaination to this apparent paradox, that this resonating capacitor - inductance system, was only valid in the context of the speaker driver and vent having the same cross-section area, quite an impractical situation as you wrote. I then asked how to represent, using the LTspice modelization, the general situation where the driver surface and vent cross-section area are different.
I hope you understand the importance of this question. It will enable me to simulate bass-reflex systems and 4th-order dual chamber passband systems, including equalizers, active filters, passive filters, acceleration feedback, speed feedback (dual voice coils drivers), negative impedance drive, current drive and so on. Everything in one single LTspiceIV schematic.
Then in the next post I asked if you could advise on the apparent paradox, about the capacitor representing the box compliance, and the inductance "related" to the vent mass, with the idea that the value of this inductance is not fixed, but completely depending on the arbitrary shape and size of the vent. I then proposed as explaination to this apparent paradox, that this resonating capacitor - inductance system, was only valid in the context of the speaker driver and vent having the same cross-section area, quite an impractical situation as you wrote. I then asked how to represent, using the LTspice modelization, the general situation where the driver surface and vent cross-section area are different.
I hope you understand the importance of this question. It will enable me to simulate bass-reflex systems and 4th-order dual chamber passband systems, including equalizers, active filters, passive filters, acceleration feedback, speed feedback (dual voice coils drivers), negative impedance drive, current drive and so on. Everything in one single LTspiceIV schematic.
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Hi,
My edit of the above timed out. I'm no SIM expert, I don't know LTspiceIV
and quite frankly I don't care when it comes to understanding speakers.
the link I posted is as good as it gets for my understanding of SPICE SIMs.
The way I understand speakers the driver area and port area don't matter.
(Depending on what your looking at, but they don't for frequency response.)
In the simplest terms Vas of the driver to Vbox matters and for the port
its effective "inductance" compared to Vbox, related ~ to CSA/length.
I assume the corrections detailed below need to be included.
rgds, sreten.
Port Length
The port length required to tune a volume of air to a specific frequency can be calculated by using the following equation:
Lv = (23562.5*Dv^2*Np/(Fb^2*Vb))-(k*Dv)
where,
Dv = port diameter (cm)
Fb = tuning frequency (Hz)
Vb = net volume (litres)
Lv = length of each port (cm)
Np = number of ports
k = end correction (normally 0.732)
The value for k, the end correction, can be fine-tuned by using the following values to derive the appropriate end correction figure for each end of the port, then adding them together
Flanged End: 0.425
Free End: 0.307
e.g. if both ends were flanged,
k = 0.425 + 0.425 = 0.850
if one flanged, one free,
k = 0.425 + 0.307 = 0.732
if both ends were free,
k = 0.307 + 0.307 = 0.614
Normally, k=0.732 is assumed
My edit of the above timed out. I'm no SIM expert, I don't know LTspiceIV
and quite frankly I don't care when it comes to understanding speakers.
the link I posted is as good as it gets for my understanding of SPICE SIMs.
The way I understand speakers the driver area and port area don't matter.
(Depending on what your looking at, but they don't for frequency response.)
In the simplest terms Vas of the driver to Vbox matters and for the port
its effective "inductance" compared to Vbox, related ~ to CSA/length.
I assume the corrections detailed below need to be included.
rgds, sreten.
Port Length
The port length required to tune a volume of air to a specific frequency can be calculated by using the following equation:
Lv = (23562.5*Dv^2*Np/(Fb^2*Vb))-(k*Dv)
where,
Dv = port diameter (cm)
Fb = tuning frequency (Hz)
Vb = net volume (litres)
Lv = length of each port (cm)
Np = number of ports
k = end correction (normally 0.732)
The value for k, the end correction, can be fine-tuned by using the following values to derive the appropriate end correction figure for each end of the port, then adding them together
Flanged End: 0.425
Free End: 0.307
e.g. if both ends were flanged,
k = 0.425 + 0.425 = 0.850
if one flanged, one free,
k = 0.425 + 0.307 = 0.732
if both ends were free,
k = 0.307 + 0.307 = 0.614
Normally, k=0.732 is assumed
Now would be a good time to give the thread back to buggson
this doesnt look like helping him one bit right now 😡
this doesnt look like helping him one bit right now 😡
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