Hi GM,
sorry i didn't respond to your question. The problem is that I'm still finding out what brand and type this driver is, since i bought this driver at the local audio-shop. The only info i have comes from a sticker on the magnet:
"Vision Acoustique
Ref: 40170DB
101352L 29001"
I already posted on this forum to ask if anybody knows this driver: http://www.diyaudio.com/forums/showthread.php?s=&threadid=59732&perpage=10&pagenumber=1
It seems that this driver is an OEM-unit from Audax.
I think this driver is used in Vision Acoustique's modell 'Eden II'.
For pictures you could visit the thread above or the audax site (Thiele & Small Parameters are different):
http://www.audax.fr/prestige/hm170g8.html
I measured the Thiele & Small Parameters myself. Because it's a dual voice coil driver i didn't know how to wire when measuring, but on this forum they told me to measure the way i'm going to use the driver, so these are the TSP when wired in series:
Re = 10,4 Ohms
Fs = 37,43 Hz
Qts = 0,19552
Qes = 0,20079
Qms = 7,44531
Vas = 26,769 L
Sd ~ 216,4 cm2 (6.5" driver)
I hope I answered your question now, maybe you know what brand/type this driver is??
best regards
sorry i didn't respond to your question. The problem is that I'm still finding out what brand and type this driver is, since i bought this driver at the local audio-shop. The only info i have comes from a sticker on the magnet:
"Vision Acoustique
Ref: 40170DB
101352L 29001"
I already posted on this forum to ask if anybody knows this driver: http://www.diyaudio.com/forums/showthread.php?s=&threadid=59732&perpage=10&pagenumber=1
It seems that this driver is an OEM-unit from Audax.
I think this driver is used in Vision Acoustique's modell 'Eden II'.
For pictures you could visit the thread above or the audax site (Thiele & Small Parameters are different):
http://www.audax.fr/prestige/hm170g8.html
I measured the Thiele & Small Parameters myself. Because it's a dual voice coil driver i didn't know how to wire when measuring, but on this forum they told me to measure the way i'm going to use the driver, so these are the TSP when wired in series:
Re = 10,4 Ohms
Fs = 37,43 Hz
Qts = 0,19552
Qes = 0,20079
Qms = 7,44531
Vas = 26,769 L
Sd ~ 216,4 cm2 (6.5" driver)
I hope I answered your question now, maybe you know what brand/type this driver is??
best regards
Paul : Because at subsonic frequencies the cone is safely loaded by the rear chamber. Also note that the driver is only loaded on one side with a BLH,so assymmetrical distortion occurs,2HD.
The effect of the capacitive rear chamber on the horn causes the peak in excursion through whatever means while the BLH doesnt. Note that high BL drivers suffer less problem here(AV12
)So the apparent increase in F3 over a BLH isnt actually usable,and is below the horn cutoff itself.
http://www.volvotreter.de/dl-section.htm
The Dinstale Horn Loudspeaker Design Articles
http://www.geocities.com/xobt/index2.html
Subwoofer shoot out(labhorn measurements)
http://srforums.prosoundweb.com/index.php/mv/msg/6891/56805/0
Labhorn excursion measurement(laser)
Amazing how close hornresp predicts to reality.
Something like
Cornerloaded
S1 : 100cm^2
Sm : 2500cm^2
Expo 255cm
Vrc 33litre
If you used Two drivers,you could reach lower or use less path length to acheive the same ~45hz cutoff
The effect of the capacitive rear chamber on the horn causes the peak in excursion through whatever means while the BLH doesnt. Note that high BL drivers suffer less problem here(AV12
)So the apparent increase in F3 over a BLH isnt actually usable,and is below the horn cutoff itself.http://www.volvotreter.de/dl-section.htm
The Dinstale Horn Loudspeaker Design Articles
http://www.geocities.com/xobt/index2.html
Subwoofer shoot out(labhorn measurements)
http://srforums.prosoundweb.com/index.php/mv/msg/6891/56805/0
Labhorn excursion measurement(laser)
Amazing how close hornresp predicts to reality.
Something like
Cornerloaded
S1 : 100cm^2
Sm : 2500cm^2
Expo 255cm
Vrc 33litre
If you used Two drivers,you could reach lower or use less path length to acheive the same ~45hz cutoff
GM you should try it,Its a large but easy download from microsoft.com I feel like ive spent a few years using it,staring at the SPL graph,wondering whats viable while considering practical size limitationsGM said:
-Ive still only made one!But designed a few which people have used elsewhere.Mike.e
What Gives????
Mark
We all give our opinions and advice freely here. Some of us including myself run consultancies. But I have never asked anyone for payment. And many times I have devoted much research and many hours to some of the answers.
If I'm wrong about this I apologise.
But if I'm correct in the assumption I think the moderators should step in.
Mark
We all give our opinions and advice freely here. Some of us including myself run consultancies. But I have never asked anyone for payment. And many times I have devoted much research and many hours to some of the answers.
If I'm wrong about this I apologise.
But if I'm correct in the assumption I think the moderators should step in.
Then GM has my full apology
To Mr. GM " I'm sorry"
I've watched a few threads get a little on the hook and lure side of things and I personally hate it.
If we post in this forum it is free advice.
Many people take their posts seriously. And if I have read enough of GM's posts he to knows what he is talking about!
Mark
To Mr. GM " I'm sorry"
I've watched a few threads get a little on the hook and lure side of things and I personally hate it.
If we post in this forum it is free advice.
Many people take their posts seriously. And if I have read enough of GM's posts he to knows what he is talking about!
Mark
Hello,
just another horn question again
I'm still busy designing a back-loaded bas horn for use in my living room. It's getting a bit confusing, because there are several ways to calculate the throat area.
I tried Leach's and Edgar's models and the equations from the BIG FUN article, but the results are different.
For example, with Edgar's method, i get a throat area of 36,78 sq. cm.
According to the BIG FUN article, i should use throat to driver ratios of 0,3 to 0,7 * sd, resulting in St=64,92 to 151,48 sq cm. Leach gives a throat area of 26,57 sq cm for a 50 Hz horn.
I already tried different values with hornresp, but i can't get a very smooth response for a BLH.
Could anyone tell me which method i should use for my BLH??
best regards
just another horn question again
I'm still busy designing a back-loaded bas horn for use in my living room. It's getting a bit confusing, because there are several ways to calculate the throat area.
I tried Leach's and Edgar's models and the equations from the BIG FUN article, but the results are different.
For example, with Edgar's method, i get a throat area of 36,78 sq. cm.
According to the BIG FUN article, i should use throat to driver ratios of 0,3 to 0,7 * sd, resulting in St=64,92 to 151,48 sq cm. Leach gives a throat area of 26,57 sq cm for a 50 Hz horn.
I already tried different values with hornresp, but i can't get a very smooth response for a BLH.
Could anyone tell me which method i should use for my BLH??
best regards
Theories and reality
Your up against the great problem we all face when we can't check out the background behind the articles. If they have a bibliography you can generally check the sources for the theories.
The best first question is what are you doing with this woofer? Are you using the horn on a full range driver and augmenting the low end? Or are you making a horn sub?
Mr. Edgar is pretty conscientious in his research. But I think that his equations refer to a front loaded horn with a reactance canceling volume on the rear of the woofer. That statement also depends on the article that you are reading.
Another person who is careful with his sources is the Hornresponse program creator Mr. Mcbean. I have used it for a couple of years and the results are generally in agreement with what comes out. The question is always the same. Are we applying the programs and the theories properly? We tend to always want the smallest package and the lowest extension. Biggest bang for the buck. Sometimes a little less extension can be traded for a better horn and less ripple. Case in point is that length can give you low end potential. But it is a smooth flare rate and the proper mouth size termination that is the most important. Meaning that there will be less to no ripple if the two are in proper balance. The two work in concert. Can't cheat physics!
RCW's statement about a back loaded horn has some merit. There are always the cancellation effects that occur when the horn and the direct driver are covering the same range. The woofer tends to have more intermodulation distortion when it is not controlled by a rear volume of air. That little trick when properly applied makes a horn sing. Mr. Edgar has written quite a bit on that point to.
One other method to check up your results is to use the ML util found on the fullrange driver website. It applies Leach's theories to horn design and it to is quite accurate when you work within its design limits.
Mark
Your up against the great problem we all face when we can't check out the background behind the articles. If they have a bibliography you can generally check the sources for the theories.
The best first question is what are you doing with this woofer? Are you using the horn on a full range driver and augmenting the low end? Or are you making a horn sub?
Mr. Edgar is pretty conscientious in his research. But I think that his equations refer to a front loaded horn with a reactance canceling volume on the rear of the woofer. That statement also depends on the article that you are reading.
Another person who is careful with his sources is the Hornresponse program creator Mr. Mcbean. I have used it for a couple of years and the results are generally in agreement with what comes out. The question is always the same. Are we applying the programs and the theories properly? We tend to always want the smallest package and the lowest extension. Biggest bang for the buck. Sometimes a little less extension can be traded for a better horn and less ripple. Case in point is that length can give you low end potential. But it is a smooth flare rate and the proper mouth size termination that is the most important. Meaning that there will be less to no ripple if the two are in proper balance. The two work in concert. Can't cheat physics!
RCW's statement about a back loaded horn has some merit. There are always the cancellation effects that occur when the horn and the direct driver are covering the same range. The woofer tends to have more intermodulation distortion when it is not controlled by a rear volume of air. That little trick when properly applied makes a horn sing. Mr. Edgar has written quite a bit on that point to.
One other method to check up your results is to use the ML util found on the fullrange driver website. It applies Leach's theories to horn design and it to is quite accurate when you work within its design limits.
Mark
Thanks for the replies!
Edgar's math comes from the Show Horn article. All the articles i read have a bibliography, but i think i'm going to use Leach's equations. Using hornresp, they seem to be accurate for a FLH design. For a BLH, the freq response has little dips and peaks, just like Edgar's math and the eq from the BIG FUN article.
best regards
Edgar's math comes from the Show Horn article. All the articles i read have a bibliography, but i think i'm going to use Leach's equations. Using hornresp, they seem to be accurate for a FLH design. For a BLH, the freq response has little dips and peaks, just like Edgar's math and the eq from the BIG FUN article.
best regards
Front to Back
A front loaded horn has no compression chamber to control the cone. A rear loaded horn does. Ideally the chamber should be sized so as to null the impedance peak that the driver develops as the coupling between the horn and the driver unloads. Obviously a front loaded horn does not have this feature. The bumps and peaks are better understood when you run the impedance response graphs under Hornresponse. They usually coincide with the frequency response peaks. THat is usually a sign that the horn is being compromised somewhere.
This is not always bad. A real in room response of any driver box combination will have similar peaks and valleys. So the real question is if you can live with them.
Check this out:
http://melhuish.org/audio/horninfo.html
Look for : ML Util.zip
THis is an easy way to apply the Leach math.
Mark
A front loaded horn has no compression chamber to control the cone. A rear loaded horn does. Ideally the chamber should be sized so as to null the impedance peak that the driver develops as the coupling between the horn and the driver unloads. Obviously a front loaded horn does not have this feature. The bumps and peaks are better understood when you run the impedance response graphs under Hornresponse. They usually coincide with the frequency response peaks. THat is usually a sign that the horn is being compromised somewhere.
This is not always bad. A real in room response of any driver box combination will have similar peaks and valleys. So the real question is if you can live with them.
Check this out:
http://melhuish.org/audio/horninfo.html
Look for : ML Util.zip
THis is an easy way to apply the Leach math.
Mark
Re: Front to Back
For clarification, the term 'front' and 'rear' are swapped in this description. Ie, a front loaded horn does have a front and rear chamber where the rear chamber is a sealed box, while a rear loaded horn only has what would typically be considered a front chamber. The front chamber is visually between the driver and the horn (although acoustically it is in parallel with the horn - the air the driver moves can either compress the air in the front chamber or drive the horn).
mwmkravchenko said:
For clarification, the term 'front' and 'rear' are swapped in this description. Ie, a front loaded horn does have a front and rear chamber where the rear chamber is a sealed box, while a rear loaded horn only has what would typically be considered a front chamber. The front chamber is visually between the driver and the horn (although acoustically it is in parallel with the horn - the air the driver moves can either compress the air in the front chamber or drive the horn).
Hi,
I'll ask the same Q again.
Assuming that you can reverse the speaker with the magnet pointing into the compression chamber or the magnet pointing down the horn.
Q1. Why should a back loaded horn be any different from a front loaded horn?
Q2. with no compression chamber on either type (FLH & BLH) is the only problem unloading when driven below the horn flare rate lower cut off frequency?
I'll ask the same Q again.
Assuming that you can reverse the speaker with the magnet pointing into the compression chamber or the magnet pointing down the horn.
Q1. Why should a back loaded horn be any different from a front loaded horn?
Q2. with no compression chamber on either type (FLH & BLH) is the only problem unloading when driven below the horn flare rate lower cut off frequency?
Q1; without the sealed chamber there is no difference.
However the back loaded horn is normally used with a wide range driver to get some low end (out of phase) from a direct radiator and the front loaded horn is not normaly used with sealed back chamber.
Q2; Yes unloading will be more extreme. Then its just an issue of . You can call it whatever you like depending on if its pointing to you or away from you
However the back loaded horn is normally used with a wide range driver to get some low end (out of phase) from a direct radiator and the front loaded horn is not normaly used with sealed back chamber.
Q2; Yes unloading will be more extreme. Then its just an issue of . You can call it whatever you like depending on if its pointing to you or away from you
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