Calculate SPL
 User Name Stay logged in? Password
 Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read Search

 Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
 3rd July 2006, 06:22 AM #1 exuviae   diyAudio Member   Join Date: Jul 2006 Calculate SPL Ok i am a bit slow, is there some calculation given an amount of watts and sensitivty that tells you a theoretical max spl? For example I have SoundStream Tarantual series T4-15 with a 91db at 1 watt at 1 meter, and will be pushing those with a 2000 watt rm Picasso PCA200D amp also from soundstream. Without sitting there figuring out exponents (2, 4, 8, 16, 32, 64, 128,256,512,1024,2048) i know this because of computer programming lol. By my faulty calculations i would only hit around 124db. I think that is right, 11 doubles in power, 3db gain for a total gain of 33db added to a sensitivity of 91db = 124. However on 1000 watts and 2 10" in a ported box i hit 138.9 on a term lab meter (official meter of db drags) and the box was to small for the speakers, and the starting sensitivity was only 82. Something just don't add up, with 2 15"'s seeing 2000 watts i should be in the 145-150 on the term-lab meters. anyone know how to figure out what the theoretical SPL should be. I use winisd and it says the same 124db, and only like 110db on my 10's.
 3rd July 2006, 02:54 PM #2 Toast_Master   diyAudio Member   Join Date: Apr 2006 Location: Tasmania, Launceston In house and car there are room and cabin gain, these increase spl tenfold up an extra 10 - 30 db, for reasons I cant fully explain, but I know is right
 5th July 2006, 08:45 AM #3 Nanook   diyAudio Member     Join Date: Feb 2004 Location: Chinook Country.Alberta ah.. a dB question ... the formula for sound pressure level increase ,not power is db=20*log(p2/p1)so for example. if p2=say 100 watts, p1=1 watt, log of 100/1 is the same as log 100(essentially)=2, then 20 * 2 is 40, therefore total accoustical db =91+40=133 similarly 1000watts=:136 dBfor power db the formula is dB=10*10log(p2/p1) this is with the assuption that Z=2 ohms total..not 1/2 ohm of course. Q?: what does SS use for spl, 91 is posted but is that 2 Ohms (voice coils in series) or 1/2 ohm (VC in ll)? also in house there may be as much as 9db "room gain" and upto 12 or 15 db "car gain"..as previously stated. __________________ stew ☮ -"A sane man in an insane world appears insane." Let's help Ruth and Dave
 5th July 2006, 08:51 AM #4 Nanook   diyAudio Member     Join Date: Feb 2004 Location: Chinook Country.Alberta db nt __________________ stew ☮ -"A sane man in an insane world appears insane." Let's help Ruth and Dave

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is Off Forum Rules
 Forum Jump User Control Panel Private Messages Subscriptions Who's Online Search Forums Forums Home Site     Site Announcements     Forum Problems Amplifiers     Solid State     Pass Labs     Tubes / Valves     Chip Amps     Class D     Power Supplies     Headphone Systems Source & Line     Analogue Source     Analog Line Level     Digital Source     Digital Line Level     PC Based Loudspeakers     Multi-Way     Full Range     Subwoofers     Planars & Exotics Live Sound     PA Systems     Instruments and Amps Design & Build     Parts     Equipment & Tools     Construction Tips     Software Tools General Interest     Car Audio     diyAudio.com Articles     Music     Everything Else Member Areas     Introductions     The Lounge     Clubs & Events     In Memoriam The Moving Image Commercial Sector     Swap Meet     Group Buys     The diyAudio Store     Vendor Forums         Vendor's Bazaar         Sonic Craft         Apex Jr         Audio Sector         Acoustic Fun         Chipamp         DIY HiFi Supply         Elekit         Elektor         Mains Cables R Us         Parts Connexion         Planet 10 hifi         Quanghao Audio Design         Siliconray Online Electronics Store         Tubelab     Manufacturers         AKSA         Audio Poutine         Musicaltech         Aussie Amplifiers         CSS         exaDevices         Feastrex         GedLee         Head 'n' HiFi - Walter         Heatsink USA         miniDSP         SITO Audio         Twin Audio         Twisted Pear         Wild Burro Audio

 Similar Threads Thread Thread Starter Forum Replies Last Post sam8888ysl Tubes / Valves 15 26th November 2007 06:48 AM p_eric Subwoofers 21 3rd November 2006 12:52 PM bogdan_borko Solid State 3 18th January 2006 11:15 PM Dave Jones Multi-Way 19 8th May 2004 02:16 AM Dave Jones Multi-Way 3 4th May 2004 09:04 PM

 New To Site? Need Help?

All times are GMT. The time now is 10:24 PM.