Putting a Q=0.853 driver into a sealed box will give a big "hump" in the LF frequency response. The high Q figure of 1 confirms this.
In a small room, or by placing the box near a boundary, you will get a very unnatural sound to male voice. Known as Bass Boom or "one note bass".
A Linkwitz transform could be used to sort this by reducing the effective Q to somewhere in the range 0.5 to 0.7
This high Q driver could be used in an open baffle, or in an infinite baffle. This would save all the effort in trying to design and build a sealed box.
In a small room, or by placing the box near a boundary, you will get a very unnatural sound to male voice. Known as Bass Boom or "one note bass".
A Linkwitz transform could be used to sort this by reducing the effective Q to somewhere in the range 0.5 to 0.7
This high Q driver could be used in an open baffle, or in an infinite baffle. This would save all the effort in trying to design and build a sealed box.
Oh thank you so much Sir for your prompt and very informative reply.
I've been longing for long to build one using an open-baffle design.
Here I have some questions.
1. Is the size of the driver Okay even for a mini-open Baffle design?
2. What will be approximate baffle size and thickness for this specific driver?
Mms measurements between -68 g and +12 g and two impedance peaks in closed box, that reminds me very much of another thread:
http://www.diyaudio.com/forums/multi-way/238046-speaker-enclosers-s-2.html#post3543951
Maybe you find some useful information there.
http://www.diyaudio.com/forums/multi-way/238046-speaker-enclosers-s-2.html#post3543951
Maybe you find some useful information there.
Thank you for posting the link. I've just given a quick look at that and my situation is identical to the OP of that thread. I will give a second look.
Kindly have a look at my earlier posted parameters and I would be grateful if you could kindly suggest a specific and optimized design for me.
I have no other software except LIMP.
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Thank you for your quick response.
I've been testing various drivers ( what's available here in my area, mainly un-branded, local ones) with OB with blind guess since some days. I like the sound. But I am yet to learn the grammar of OB.
I use active amplifier and equalizer. So I guess equalizing those won't pose a problem.
Could you kindly post some links to diy friendly OB reading material that is easier to comprehend and any free software to design OB?
I was reading your very useful link that you posted earlier and found an easier way to calibrate limp.
So I'm re-doing/modding the limp-jig now and I will post the result of the new test if they differ from the earlier one.
Also I am awaiting the response from Sir Andrew.
Thank you.
...................................................................................
Update:
I also tried my best to measure effective cone size which is 12.2 cm.
With new procedure of calibration vas is reduced now!
Thiele-Small parameters:
Tested with pink noise:
Fs = 74.55 Hz
Re = 8.00 ohms[dc]
Le = 1238.74 uH
L2 = 2017.01 uH
R2 = 3.83 ohms
Qt = 0.83
Qes = 0.96
Qms = 6.04
Mms = 11.08 grams
Rms = 0.858869 kg/s
Cms = 0.000411 m/N
Vas = 7.89 liters
Sd= 116.90 cm^2
Bl = 6.579041 Tm
ETA = 0.33 %
Lp(2.83V/1m) = 87.26 dB
Added Mass Method:
Added mass = 10.00 grams
Diameter= 12.20 cm
******************************************
Thiele-Small parameters:
Tested with Stepped Sine wave:
Fs = 72.51 Hz
Re = 8.00 ohms[dc]
Le = 1272.69 uH
L2 = 2303.91 uH
R2 = 3.55 ohms
Qt = 0.90
Qes = 1.06
Qms = 6.01
Mms = 10.81 grams
Rms = 0.819442 kg/s
Cms = 0.000446 m/N
Vas = 8.56 liters
Sd= 116.90 cm^2
Bl = 6.101374 Tm
ETA = 0.30 %
Lp(2.83V/1m) = 86.82 dB
Added Mass Method:
Added mass = 10.00 grams
Diameter= 12.20 cm
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Thank you so much
Greebster,
kbzx35,
cT equals piD,
Absconditus,
gootee,
AndrewT and
Dissi
for the kind help of yours.
I am feeling confident now with the ABC of the speaker enclosure building.
I made a sealed enclosure two "specs-not-available drivers" for the centre channel after obtaining the parameters with LIMP and it's working nicely.
I checked with the old trusted method mentioned/taught by cT equals piD and then compared the result with what I got with the help of software and web based tools. And both were identical and so I went forward with confidence and the result is satisfactory, I can say.
I also tuned my sub enclosures and now they are going deeper.
Thanks a ton really, to all of you!
Here are some snaps.
Greebster,
kbzx35,
cT equals piD,
Absconditus,
gootee,
AndrewT and
Dissi
for the kind help of yours.
I am feeling confident now with the ABC of the speaker enclosure building.
I made a sealed enclosure two "specs-not-available drivers" for the centre channel after obtaining the parameters with LIMP and it's working nicely.
I checked with the old trusted method mentioned/taught by cT equals piD and then compared the result with what I got with the help of software and web based tools. And both were identical and so I went forward with confidence and the result is satisfactory, I can say.
I also tuned my sub enclosures and now they are going deeper.
Thanks a ton really, to all of you!
Here are some snaps.
Attachments
I thank you Tom for your kind words.
The awesome association and constant handholding of respected, kind and very knowledgeable people like you all are the real privilege for a half educated man with no formal technical background like myself.
So the real credit goes to you all for your patience, suggestion, teaching and guidance.
I am just following all of your footsteps and getting amazed as I am learning new things day by day.
Just finished a ported box tuned at 70 Hz.
Polishing, retouching are yet to be done.
It sounds very good.
Tested with TrueRTA and other freebies.
With the help of PC, it's just a child's play now.
I used Box tune calculator, an android applet, to build the enclosure.
Next plan is to build a T-line with cheap local full range speakers.
Thank you so much all again.
Polishing, retouching are yet to be done.
It sounds very good.
Tested with TrueRTA and other freebies.
With the help of PC, it's just a child's play now.
I used Box tune calculator, an android applet, to build the enclosure.
Next plan is to build a T-line with cheap local full range speakers.
Thank you so much all again.
Attachments
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