Wattages & Loudness: ?I'm Lost?
 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

 Tubes / Valves All about our sweet vacuum tubes :) Threads about Musical Instrument Amps of all kinds should be in the Instruments & Amps forum

 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
 12th August 2004, 03:51 PM #1 edsmith   diyAudio Member   Join Date: Mar 2004 Location: Australia Wattages & Loudness: ?I'm Lost? I kind of gathered from reading post/articles that tube amplifiers rated at 10w will be not much different in max volume to say a 20watt amp. Could someone please explain this in more detail. Are the average joe's out there being in a way misled when told a 100 watt amp will be twice the volume of a 50watt. I'm talking guitar amps if that has anything to do with it. Just curious, Ed
AudioFreak
Warp Engineer
On Holiday

Join Date: Oct 2001
Location: Queensland, Australia
Re: Wattages & Loudness: ?I'm Lost?

Quote:
 Originally posted by edsmith I kind of gathered from reading post/articles that tube amplifiers rated at 10w will be not much different in max volume to say a 20watt amp. Could someone please explain this in more detail. Are the average joe's out there being in a way misled when told a 100 watt amp will be twice the volume of a 50watt. I'm talking guitar amps if that has anything to do with it. Just curious, Ed
For the volume to sound twice as loud, you need 10 times the power.
__________________
- Dan

Sheldon
diyAudio Member

Join Date: Dec 2003
Location: San Diego
Re: Re: Wattages & Loudness: ?I'm Lost?

Quote:
 Originally posted by AudioFreak For the volume to sound twice as loud, you need 10 times the power.
True mathematically, but is that always true if we are talking about perception?

Sheldon

 12th August 2004, 05:23 PM #4 rkc7   diyAudio Member     Join Date: May 2004 Location: Toledo, OH Want the physics? http://www.physicsclassroom.com/Class/sound/U11L2b.html Generally speaking, 10dB increase is double the "loudness", and it's understood that it takes 10x the power output of a speaker to have a 10dB increase in intensity or twice as loud. So going from a 10w amp to a 20w amp would probably only give about a 2db increase. The decibel is the standard unit for the smallest perceivable change in intensity, so 2db will probably not be very noticeable. Of course if you go from 10w to 100w, it should give a 10db increase. And if you go from 10w to 1000w, it should be a 20db increase or 4 times as loud. Now to be twice as loud from 1000w, it would take 10000w.... so you can see how it quickly become infeasible to really increase the sound intensity output above a certain point. Now it comes down to speaker sensitivity on how much dB ouput you get. But then you have another problem.... the longer you listen to listen to loud volumes, the louder you'll have to turn it up to get the same effect as time goes on.
Sheldon
diyAudio Member

Join Date: Dec 2003
Location: San Diego
Quote:
 Originally posted by rkc7 Want the physics? http://www.physicsclassroom.com/Class/sound/U11L2b.html Generally speaking, 10dB increase is double the "loudness", and it's understood that it takes 10x the power output of a speaker to have a 10dB increase in intensity or twice as loud. So going from a 10w amp to a 20w amp would probably only give about a 2db increase. The decibel is the standard unit for the smallest perceivable change in intensity, so 2db will probably not be very noticeable. Of course if you go from 10w to 100w, it should give a 10db increase. And if you go from 10w to 1000w, it should be a 20db increase or 4 times as loud. Now to be twice as loud from 1000w, it would take 10000w.... so you can see how it quickly become infeasible to really increase the sound intensity output above a certain point. Now it comes down to speaker sensitivity on how much dB ouput you get. But then you have another problem.... the longer you listen to listen to loud volumes, the louder you'll have to turn it up to get the same effect as time goes on.

I understand the physics. Sorry, I should have worded the question better. I was interested in perception. If you ask a test subject to turn up the volume until it appears to them that it twice as loud (however they personally judge it), how well does that correlate to a measured 10db? Or, how much does that vary from person to person. I'm sure this data would be easy for me to find, just thought it likely someone here would know.

Sheldon

 12th August 2004, 06:30 PM #6 SY   On Hiatus     Join Date: Oct 2002 Location: Chicagoland 10 dB was the accepted average for a perceived doubling in loudness, but IIRC that number is considered to be a bit too high now. What complicates things is that this is an instrument amp- the loudness stuff is all done with non-distorting components in a chain, a sound reproduction rule of thumb. Once you add distortion, changes in spectral content with volume, acoustic feedback and the like, it gets much tougher to correlate perceived loudness with watts of amp power. __________________ "You tell me whar a man gits his corn pone, en I'll tell you what his 'pinions is."
 12th August 2004, 08:00 PM #7 Sch3mat1c   diyAudio Member     Join Date: Jan 2003 Location: Milwaukee, WI As you can see, most of the subtlety comes in the 1W range. But my 10W 6V6 PP amp is still better than your 6S4 PSE. (I have more "subtlety", aka dynamic range.) Tim __________________ Seven Transistor Labs, LLC Projects and Resources / Electronic Design and Consultation
BillFitzmaurice
Banned

Join Date: May 2004
Location: New Hampshire
Quote:
 I kind of gathered from reading post/articles that tube amplifiers rated at 10w will be not much different in max volume to say a 20watt amp.
The difference will be 3dB; the human ear responds to volume changes logarithmically, so it does take on average a 10dB increase to sound 'twice as loud'. This is also affected by the frequency bandwidth and individual frequencies for that matter, but 10dB will do to keep things simple.

But this is less than half the picture, as the output of an amp in watts is almost meaningless when compared to the sensitivity of the loudspeakers being used. A loudspeaker sensitivity increase of 3dB gets you the same result as doubling wattage with no power increase. Loudspeaker sensitivities can run anywhere from 85dB/watt to 110dB/watt on average. To get a definitive idea of how loud two different systems will be you must compare both the amplifier wattage and the speaker sensitivity to arrive at the potential dB output capabilities of the two.

www.billfitzmaurice.com

 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     Room Acoustics & Mods     Music     diyAudio.com Articles     Car Audio     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         Holton Precision Audio         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 ballsingtripp Chip Amps 18 12th March 2009 08:22 AM Phil Olson Multi-Way 19 29th March 2008 01:14 AM pigophone Multi-Way 12 4th March 2008 03:47 PM pityocamptes Car Audio 4 2nd October 2007 09:24 PM

 New To Site? Need Help?

All times are GMT. The time now is 09:45 AM.

 Home - Contact Us - Advertise - Rules - diyAudio Store - Sponsors - Privacy Statement - Terms of Service - Top - Opt-out policy

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.