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Old 23rd June 2008, 13:54   #31
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gunbir,
here i am hoping that the young guns will get creative and build transmission line subs in their trunks and more and there you are raining on my parade with reality. :-)
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Old 24th June 2008, 17:53   #32
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absolutely immaculate installs on both cars. could someone post or PM me the installer details in BLR.
thanks
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Old 24th June 2008, 19:11   #33
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Quote:
Originally Posted by navin View Post
The cones of these woofers are rather heavy and I worry about cone sag (even considering the 2 spider suspensions some of these leviathans use) affecting the T/S specs and Xmax over long term use.
Whats the other option? Install it sideways? That would be even worse if this causes the moving parts to be misaligned along the horizontal axis, more so if the sub has a large winding width/ shallow cone and long former etc..
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Old 24th June 2008, 22:03   #34
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Originally Posted by Bass&Trouble View Post
Whats the other option? Install it sideways? That would be even worse if this causes the moving parts to be misaligned along the horizontal axis, more so if the sub has a large winding width/ shallow cone and long former etc..
B&T, if the suspension of a sub cannto support the cone when the cone is vertical the sub needs a re-design. I have used 18" woofers with no trouble this way. Yet many manufacturers actually issue warnings that their subs should NOT be installed face down or face up (usually these subs are those with heavy cones).
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Old 25th June 2008, 00:48   #35
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Quote:
Originally Posted by navin View Post
B&T, if the suspension of a sub cannto support the cone when the cone is vertical the sub needs a re-design. I have used 18" woofers with no trouble this way. Yet many manufacturers actually issue warnings that their subs should NOT be installed face down or face up (usually these subs are those with heavy cones).
Like? Can you tell me which company subs your talking about here?
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Old 25th June 2008, 11:06   #36
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Quote:
Originally Posted by CorsaLove View Post
Like? Can you tell me which company subs your talking about here?
I have seen some woofers sag like the famous "1259" woofer that was used in the NHT 3.3 tower. These woofers used high Mms and soft Cms to reach low Fs in a small Vb (or Vas). There are many speakers that are resistant to cone sag as well.

I experienced the effects of cone sag only once using a 18" EV woofer. A replacement from JBL (2245) did not exhibit this although the trade off was a higher Fs and hence F(-3db) in the same box.

Good woofers from companies like ScanSpeak, Seas, Focal, Dynaudio, etc.. should resist cone sag but if you see a woofer whose cone mass is heavy (100gms+) and whose compliance is soft be wary. In fact if you ever see numbers where the Vas is small while the Fs is low be sure to check the Mms and Cms numbers.

some people go as far as to recommend rotating woofers that are mounted vertically as well, while this may be true in theory I have not seen any woofer that requires this.
Speakers

I got this from the diyaudio archvies which got it from the Adire site

Driver suspension compliance (Cms) = Vas / (1180 * c^2 * (Sd/10000)^2)
Driver mass (Mms) = 1 / ((2*pi*Fs)^2 * Cms)
Sag = Cms * Mms * g (where g = 9.81 m/s^2)
If the sag is more than 5% of the Xmax of the driver, then it's not meant for horizontal mounting

also see
http://www.adireaudio.com/tech_pape...orientation.htm
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Old 30th June 2008, 10:57   #37
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Quote:
Originally Posted by jesal View Post
i would really like to see pics of that black car in the background with those yummy rims please. thanks
Did you mean this one?
Attached Thumbnails
Nice installs from Bangalore...-swift.jpg  

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Old 30th June 2008, 11:05   #38
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Quote:
Originally Posted by gunbir View Post
Did you mean this one?
oh my god its a swift i thought it was some import huge suv or something. sexy mate, do you have some more pics.
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Old 30th June 2008, 11:18   #39
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Thats one sexy looking Swift. Good mags mate.
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Old 30th June 2008, 11:27   #40
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Quote:
Originally Posted by navin View Post

Navin Ji Adire is long gone...I really want to have few of there stuff chalo..

here is the write of the same...

CALCULATING DRIVER SAG AND SUITABILITY FOR
VERTICAL MOUNTING
Often times, you'd like to mount a driver facing down, such as in a Sonotube™ enclosure. However, you
may not be sure whether the driver you have is suitable for such an arrangement. Will the driver hold up to
horizontal mounting? Will the relentless pull of gravity be too much, and cause intolerable amounts of
sag?
Well, there's actually a way to calculate the sag a driver will exhibit when mounted in a downfiring (or
upfiring) position! And you don't need anything more than the Fs, Vas, effective surface area (Sd), and the
Xmax of the driver.
To calculate the sag, we first need to calculate the acoustic compliance of the driver. That is, how soft is
the suspension? This parameter is called Cms, and is related to Vas. Cms is the acoustic compliance of the
driver, and has the units of meters per Newton. It is calculated as:
Cms = Vas / (1180 * c^2 * (Sd/10000)^2)
where
Vas is the equivalent compliance of the driver, in liters
c is the speed of sound, in m/s (use 343 m/s as a good approximation)
Sd is the effective surface area of the driver, in square cm
Note that you can use the following rough Sd estimates for drivers: 8” = 230, 10” = 340, 12” = 480, 15” =
800, 18” = 1150.
Now that we have the Cms of the driver, we'll need to calculate the effective mass of the driver, Mmd. For
this, we'll need Cms and Fs.
Mms = 1 / ((2*pi*Fs)^2 * Cms)
where
pi = 3.1415927...
Fs is the resonant frequency, in Hz
Cms is as calculated above
So, with the Mms and Cms, we're almost there. To calculate the actual sag, you'll need to multiply the
stiffness of the suspension times the mass of the diphragm times the pull of gravity:
Sag = Cms * Mms * g
where
Cms is as calculated above
Mms is as calculated above
g is the acceleration of gravity (9.81 m/s2)
This will give us the sag in meters. So, multiply by 1000 to get to millimeters. Here's an example, using
our Shiva subwoofer:
Vas = 136.6 liters
Fs = 21.6 Hz
Sd = 481 cm^2
Calculating Driver Sag and Suitability for Vertical Mounting 2
So, we calculate the Cms as:
Cms = Vas / (1180 * c^2 * (Sd/10000)^2)
Cms = 136.6 / (1180 * 343^2 * (481/10000)^2)
Cms = 0.0004253
So, now we calculate the Mms:
Mms = 1 / ((2*pi*Fs)^2 * Cms)
Mms = 1 / (2 * 3.1415927 * 21.6)^2 * 0.0004253)
Mms = 0.12766 kilograms
or 127.66 grams. Lastly, we need to calculate the sag of the driver:
Sag = Cms * Mms * g
Sag = 0.0004253 * 0.12766 * 9.81
Sag = 0.0005326 meters
Sag = 0.5326mm.
So, that's all fine and dandy. We can calculate sag. But what does it mean, and how can it tell us if the
driver is OK for horizontal mounting? Well, as a general rule-of-thumb, we use the following:
If the sag is more than 5% If the sag is more than 5% of the Xmax of the driver, then it's not meant for
horizontal mounting.
Simply put, if you lose more than 1/20th of your Xmax from sag, then it shouldn't be mounted that way.
To finish off the example, let's look at Shiva:
Xmax = 15.9mm one way
Sag = 0.5326mm
Percent Sag = (Sag / Xmax) * 100
Percent Sag = (0.5326 / 15.9) * 100
Percent Sag = 3.35%
So, Shiva would be OK for horizontal mounting. And now you can calculate the suitability of your favorite
driver, too! Just run the numbers, and if you're less than 5% of Xmax, you're sitting pretty!

Last edited by low_bass_makker : 30th June 2008 at 11:28.
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Old 30th June 2008, 11:33   #41
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Quote:
Originally Posted by gunbir View Post
Did you mean this one?
I didnt read all this ICE-VICE business, but that is one cool looking swift and quite a nice picture (lots of PP potential)

cya
R
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Old 30th June 2008, 14:54   #42
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Quote:
Originally Posted by gunbir View Post
Did you mean this one?
now where in Delhi did you get Sea? LOL just kiddding
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Old 30th June 2008, 20:41   #43
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Quote:
Originally Posted by gunbir View Post
Did you mean this one?

Amazing wheels! Gunbir, can you please PM me the installers name in Bangalore?

Thanks..
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Old 2nd July 2008, 17:11   #44
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yes, please PM the installers name in BLR
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