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Watts vs Volume (db)

Started by joecool85, December 22, 2010, 08:56:56 AM

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saturated

Quote from: g1 on April 05, 2014, 01:37:52 PMIn car audio competitions you measure SPL.  Does a given system with a 200W amp sound twice as loud as the same system with a 100W amp?


I got tickled when I read this  :) as much as I groan when I hear them thumpers driving by I am intrigued by the idea of a contest which I presume the goal is to be the loudest?

If so I think I will keep an eye out for any local event like that it would be fun to watch
 8)
I ask stupid questions
and make stupid mistakes

criticism, critique, derision, flaming, verbal abuse welcome

JonnyDeth

Quote from: saturated on March 26, 2024, 02:34:14 PM
Quote from: g1 on April 05, 2014, 01:37:52 PMIn car audio competitions you measure SPL.  Does a given system with a 200W amp sound twice as loud as the same system with a 100W amp?


I got tickled when I read this  :) as much as I groan when I hear them thumpers driving by I am intrigued by the idea of a contest which I presume the goal is to be the loudest?

If so I think I will keep an eye out for any local event like that it would be fun to watch
 8)

That question is why you really want to understand what VAR is, how to calculate the capacitor for your selected speaker, and then run tests using a sine wave @100 Hz to see how many VAR/Watts it actually sees from that amplifier, probably 10 Khz or at least around 6 to 7 too.

The kid that set the original world record that's since been broken used a specific series of pioneer subwoofer and that series of subwoofer amplifier. Pioneer spared no expense and recruited a degree bearing engineer and techs to design the entire line. They designed the amps so what they produced @1 Khz was also the same as they produced @100 Hz as well as all the way down to 25 Hz, this is why VAR is actually a critical detail when it comes to how much volume you can expect from the lows, mids and highs of a particular woofer and amplifier set, and what is the quality also going to be like.

A speaker whose resonance Q ranges down to 100Hz and still sees 75% of the VAR/watts it will see at 1 Khz will be an absolute monster, even if it's only rated for 90dB rather than 100. The dB sensitivity is still generated by 1-watt @1 meter, so it's not the critically defining feature to how much volume it's ultimately going to produce. It's just a test produce for reference when you're speaker shopping. If it's 110dB vs 95dB, but the 95dB speaker handles 5x the wattage, it's generally going to be louder than the one rated at 110dB when you max their wattage, but it won't be obscene when you compare them, and it's also likely to be better quality in sound fidelity.

I don't have extremely deep interest in car audio, but I do like having a competition class subwoofer in the trunk of my vehicle. My focus for audio engineering will always be focused on music equipment, but also when it comes to signal processing technology, that's going to include car too. I have some rather clever ideas for subwoofer crossovers that will give you brutal volume and thump out of a cheap ass subwoofer and amplifier that I've used in the past. When I finally moved to a competition subwoofer and much stronger power amplifier, it was significantly louder, but only about 20% with a significant amount of rumble. The cheapo was still only about $80 total investment excluding the enclosure I built, and the competition one setup was about $350! It was definitely worth it, but it also wasn't an obscenely dominating increase in performance. I've also been through 3 competitions subwoofers since that one after accidently frying it and having to buy 2 more is what was obscene.