Amp output/efficiency?

[Hoemygosh 0]

Alright guys.

I picked up a Hifonics BXX2000.1D for my Fi BLv3 18. A good friend of mine has a scope, so we dialed in gains on a 0db 50hz test tone. I have the electrical to feed it. I’m able to maintain voltage at full tilt. 
 

I was reading about power and impedance rise and decided to clamp the amp and get some readings for myself. I’ll save you the time in telling me “it’s a hifonics amp, you get what you pay for... etc” I’m fully aware. I plan on going Sundown this spring with tax money. However, I’ve ran a few HF amps in the past and have been satisfied.

 

I ran test tones at full tilt, 20hz to 55hz, measured AC voltage at speaker output terminals, and AC amperage output clamped on positive speaker lead. Wired to 1 ohm. Wrote everything down, popped into a spreadsheet, and now I’m a little concerned with the output I’m getting. 
 

Watts calculated = Amps x Volts

Impedance calculated = Volts / Amps

 

From what I understand, the rise and peaks go hand in hand accurately.. but less than 300w actual output??? Am I missing something? I understand HF doesn’t usually “rate” at RMS if ever at all.. but wtf. Can anyone offer any input? Does this sound right, is something up? 

[Tirefryr 1,742]

Music iz dynamic and driver characteristics change in milliseconds.  If you think that's bad, calculate your acoustic watts.  You'll really shit then.

[Hoemygosh 0]

6 hours ago, Tirefryr said:

Music iz dynamic and driver characteristics change in milliseconds.  If you think that's bad, calculate your acoustic watts.  You'll really shit then.

So playing a test tone at the same frequency of a sustained note within a song isn't the same? I'm here to learn, so definitely direct me to where I need to read to understand the difference. I always assumed that a test tone would play the same as the same frequency note of a song. (example, Ying Yang Twins - Salt Shaker I believe is a 39?hz note) but it won't draw/sound the same as a 39hz test tone?

[Tirefryr 1,742]

Think of the tone as a static load.  It doesn't change.  It's not that cut and dry, but a generalization.  That 39Hz note in a song could be measured but it's amplitude won't be the same, all other factors being equal because the dynamic load present on the amplifier before and after that note from the dynamics of the music.

 

Think of it this way;  your faucet on your sink breaks and the water is flowing at a constant rate (i.e. the tone), and your other faucet breaks but this one has the water pulsating while sometimes reaching the same constant rate as the other faucet , and sometimes not. 

 

A rollercoaster is another good example.  Say we have 12 hills all the same height, length, and profile.  The forces exerted will be the same throughout the ride.  We build a different coaster with one hill the same size as the first coaster, but all others vary in difference to this one and the forces will differ for the duration of the ride.  This is rudimentary, but it gives a fundamental understanding, or a picture if you will.

[Hoemygosh 0]

Thanks Tirefryr.. that all makes sense. I've done a ton more reading over the course of today and finally had an AHA! moment. Especially regarding the data I already had from trying to find my box rise. 

The thing I wasn't grasping previously was the fact that yes, the coils are wired to 1ohm.. but the amp itself isn't actually seeing that low of impedance. Especially after going through the above data and running the average, which came out to 2.64ohm. It now makes sense that I can't expect to see 1 ohm power rating output from an amp that's seeing almost triple that on average.. Regardless of how cheap or expensive the amp is. So I think I've kinda learned my own answer after slowing down to read and think a little more. For what its worth though, I did stop at a buddy's house today to use his SPL Lab meter.. 140 flat from the dash on one of my favorite tunes by E40. Not a huge number... but I think mildly respectable considering the power situation? 

[kirill007 52]

Did you disconnect the subwoofer from the amp while setting gains?

Set the gains again with a -6dB test tone, music is dynamic and will never reach 0dB.