Audio watt meter for speakers?

[Sokel]

That sounds nifty. I'd love to see a demo.

That's the specs of the module's meters:

I seen some on diyaudio that use it,putting meters and stuff.
I have only tested it with my DMM to see and it's cool!

I only have to stop being lazy and make a really nice case for them but first I have to find nice meters and it might take a while.
(I'm super superficial,I admit it,it will be either a scrap board or a really nice case,nothing in between )

 

[Blumlein 88]

That's the specs of the module's meters:

View attachment 264918

View attachment 264919

I seen some on diyaudio that use it,putting meters and stuff.
I have only tested it with my DMM to see and it's cool!

I only have to stop being lazy and make a really nice case for them but first I have to find nice meters and it might take a while.
(I'm super superficial,I admit it,it will be either a scrap board or a really nice case,nothing in between )

You going with some big old analog meters? I tell you what, some of those old vacuum tube magic eye's would be really cool. You could silkscreen the watt reading around the edge.

Of course there are LED replacements or simulators of the old tube version.

 

[sarumbear]

Thanks to all who responded. So, it took a bit, but I finally bought a clamp amp meter and did some measurements. I would appreciate a sanity check here - I might be mis-using my measuring tools.

For a 30 second section of a bassy electronic track, I'm coming up with the following numbers:

0.228 A (peak)
2.1 V (peak)

That works out to:

0.4788 watts at 9.21805 ohms.

This is getting me the following peak measured volume (phone app):

77 db @ 17 feet
83 db @ 8 feet

My speakers are pretty sensitive, but do I really only need half a watt to get to loud (80 db?).

If there's an error here, let me know where you think it might be.

The issue you most likely have is that the measuring devices will not measure most audio frequencies. They are designed for mains which is 50-60Hz. I won’t be surprised they fail above 300-400Hz tops.

You can place a low value resistor and measure the voltage drop across it AND the voltage output of the amplifier simultaneously then use Ohm’s law to calculate the power.

 

[Sokel]

You going with some big old analog meters? I tell you what, some of those old vacuum tube magic eye's would be really cool. You could silkscreen the watt reading around the edge.

Of course there are LED replacements or simulators of the old tube version.

Tubey ones are cool but as I always use golden ratio cases that's a party breaker.
I REALLY like the old big industrial amp or Volt meters,not VU ,the ones that the needle centers in the middle,so it's handy with the Ice's 12-0-12 V.
Problem is that they are hard to find at the dimensions I want.

 

[Berwhale]

Go oldschool...

Vintage Radio Shack Realistic Audio Power Meter APM-100 -UNTESTED | eBay

Find many great new & used options and get the best deals for Vintage Radio Shack Realistic Audio Power Meter APM-100 -UNTESTED at the best online prices at eBay! Free shipping for many products!

www.ebay.com

JSmith

I love how someone has added Dymo tape labels to indicate left and right

 

[Blumlein 88]

I love how someone has added Dymo tape labels to indicate left and right

I'd say over half I'd seen in my life had some kind of Dymo tape. Not usually left or right, but max power or amp name or some such. A fad I guess.

 

[Blumlein 88]

Tubey ones are cool but as I always use golden ratio cases that's a party breaker.
I REALLY like the old big industrial amp or Volt meters,not VU ,the ones that the needle centers in the middle,so it's handy with the Ice's 12-0-12 V.
Problem is that they are hard to find at the dimensions I want.

Well you could use the LEDs to simulate a linear magic eye and make it golden ratio.

Where I worked they scrapped a power distribution center. Dozens of those old big meters from the 1940s. I wanted to take them home, but rules prevented employees from doing that. So they were hauled away for scrap.

 

[Sokel]

Where I worked they scrapped a power distribution center. Dozens of those old big meters from the 1940s. I wanted to take them home, but rules prevented employees from doing that. So they were hauled away for scrap.

That's exactly what I want.
Some of them are so beautiful I want to cry:

(Rules,ha? Pity)

 

[GeorgeBynum]

Just for grins, 15 or so years ago, I hooked up a data acquisition system to dynamically monitor pressure in a constant flow system, 1000 samples/sec. I calculated power in the acquisition system software, but could have done it in a spreadsheet program like Excel. Look at the DI-188 or DI-1100 from dataq.com which will probably give you a pretty good idea. They have 12 bit resolution which would give about 65 dB range. Either of these is under $100; what I used, bought in 2000, was well over 15* that. Remember that the load impedance is not constant across frequencies, so an ACCURATE number will require more knowledge. You could add series resistance and use 2 more differential channels to calculate current.

I'm not going to push a brand, but do recognize that you want differential inputs as most amplifiers today do not have a common output connection.