The ask Tin about audio thread

**raroz28** · 04-24-2015, 08:01 AM

I got rid of the bridging and switched it to 2 channel mode.

It cooled it down a lot and is still just as loud. I am confused. I thought if I bridged it, it put out 180/rms per channel. If I did that, i could turn the gain down by half and get the 90w to each speaker and put less load on the amp.

Now I'm running in 2 channel mode with the gain at about 75% and it is a lot cooler.

**Tin** · 04-24-2015, 08:32 AM

Originally Posted by raroz28

I got rid of the bridging and switched it to 2 channel mode.

It cooled it down a lot and is still just as loud. I am confused. I thought if I bridged it, it put out 180/rms per channel. If I did that, i could turn the gain down by half and get the 90w to each speaker and put less load on the amp.

Now I'm running in 2 channel mode with the gain at about 75% and it is a lot cooler.

Watts aren't a good measure of how capable an amplifier is, it's all in the power supply and how it handles voltage peaks. My 3W (yes, 3 stinkin' watts) tube amplifier I sold a few months back had a very stout power supply, and when it needed could provide an extra 10dB of headroom in very short bursts. Your typical amplifier will only provide another 3dB to 5dB of headroom, even the megabuck stuff only afforded by the well-to-do. Every +5dB increase in volume is perceived as twice as loud by the human ear. The other part of the equation is speaker efficiency. An amplifier needs to provide twice the output power to raise the dB level 3dB, and then you have the maximum acoustic output of your particular speakers. If they're only capable of 110dB SPL and are 87dB 1W/m efficient, you really don't need that much amplifier to drive them. With 1W of input power, your ears will get 87dB of sound at a 1 meter distance. Here's a little example chart for you, assuming your speakers are 87dB 1W/m. Wattage output is a means to market amplifiers. 99% of the time, most people are only using a couple of watts of power while listening.

Input power: dB SPL @ 1m:
1W 87dB
2W 90dB
4W 93dB
8W 96dB
16W 99dB
32W 102dB
64W 105dB
128W 108dB
256W 111dB

Conversation level is around 60dB, a jackhammer is 100dB, and a rock concert is about 110dB, FWIW. I normally listen to music at 80 to 85dB, and that's pretty fucking loud

**347convert** · 05-11-2015, 09:58 PM

https://en.m.wikipedia.org/wiki/One_...rmal_Challenge

**Tin** · 05-12-2015, 05:33 AM

Originally Posted by 347convert

https://en.m.wikipedia.org/wiki/One_...rmal_Challenge

James Randi is my hero

**347convert** · 05-12-2015, 09:21 AM

I thought you would like that

**Tin** · 05-12-2015, 09:35 AM

Originally Posted by 347convert

I thought you would like that

Truer words have never been spoken.

“There exists in society a very special class of persons that I have always referred to as the Believers. These are folks who have chosen to accept a certain religion, philosophy, theory, idea or notion and cling to that belief regardless of any evidence that might, for anyone else, bring it into doubt. They are the ones who encourage and support the fanatics and the frauds of any given age. No amount of evidence, no matter how strong, will bring them any enlightenment. They are the sheep who beg to be fleeced and butchered, and who will battle fiercely to preserve their right to be victimized.”