Few questions about sub |
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Spear
Registered User Joined: 14 April 2015 Status: Offline Points: 19 |
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Posted: 14 April 2015 at 8:08pm |
Hello
I am new on forum. I wanna build my first subwoofer.. I would like to build G SUB for the first time. P Audio 18" 1700W, 12.8kg , 476mm (428mm for installation), 30-200Hz, Fs=42Hz, Qts=0.59 , VAS=99.72 , BL=25.91 T/m, Re=5.2Ohm Does this fit in G SUB? What kind of wood should I use? And what kind of glue? Edited by Spear - 15 April 2015 at 1:58am |
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Spear
Registered User Joined: 14 April 2015 Status: Offline Points: 19 |
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P Audio SD18-1700EL
18" Diameter 1700W AES, 6800W Peak, 8 Ohm 4.5" Voice Coil 98 dB Sensitivity 30-200 Hz Frequency Range Edited by Spear - 15 April 2015 at 1:54am |
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_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
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Qts too high for reflex.
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djk
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Spear
Registered User Joined: 14 April 2015 Status: Offline Points: 19 |
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just found this
http://speakerplans.com/index.php?id=faq1 Qts: Driver total Q. It had to happen at some point, we’ve hit the Q word. Q is basically a describing word, it is used to describe a quality or characteristic about an electrical or mechanical part of the driver. So Qts is the overall Q of the driver, both electrical and mechanical. Qts can be thought of as how strong the motor and magnet system are. A driver with a low Qts of around 0.20 would have a large magnet and be able to move the cone with a lot of force. This makes for a tight driver. A driver with a Qts of 0.45 would have a smaller magnet and less control over its cone. So low values of Qts give a tight and punchy sound but with little weight or low bass and high Qts values give a slow and heavy sound that will give you lots of low frequency output. Watch out for drivers with really high Qts values of 0.6 or above, these would require such a big box to work correctly that in normal size boxes you don’t get much low end. They are better of being used on the rear parcel shelf of your car, where they can enjoy a massive rear chamber. SO LOOKS LIKE HIGH Qts IS GOOD FOR LOW FREQUENCY (and I like DUB BASS) Edited by Spear - 15 April 2015 at 5:49pm |
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_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
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It will work, but the bass will have a 'loose' character, rather than a 'tight' character.
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djk
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MarjanM
Old Croc Joined: 10 February 2005 Location: Macedonia Status: Offline Points: 7810 |
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G sub is too small for that driver.
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Marjan Milosevic
MM-Acoustics www.mm-acoustics.com https://www.facebook.com/pages/MM-Acoustics/608901282527713 |
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_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
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That's not what he want's to hear!
Box size is roughly proportional to the square of the Qts, .3^2=.09, .6^2=.36, so the box size for the Qts=.6 woofer will need to be about 4x bigger than for the Qts=.3 woofer (assuming similar Vas). Edited by _djk_ - 16 April 2015 at 2:41am |
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djk
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bitSmasher
Old Croc Joined: 23 June 2012 Location: Melbourne Status: Offline Points: 2296 |
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Good place for me to clarify what I've read... that a high QTS (up to 0.6 or so) will want the box volume above Vas, and tuned below Fs
So you end up with a huge box that'll go low, but also suffers from high group delay Would this be a correct summary? |
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_djk_
Old Croc Joined: 23 November 2004 Location: United States Status: Offline Points: 6002 |
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Yes.
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djk
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Elliot Thompson
Old Croc Joined: 02 April 2004 Location: United States Status: Offline Points: 5172 |
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Group delay revolves around the tuning frequency. Every reflex box offers a group delay. It is just a matter on where the measured (not simulated) tuning frequency lies. Best Regards, |
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Elliot Thompson
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bitSmasher
Old Croc Joined: 23 June 2012 Location: Melbourne Status: Offline Points: 2296 |
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