Help deciphering speaker specs

[chrisb]

Oh, I don't doubt for a minute that a lower noise floor is desirable - perhaps to a point. I have raging tinnitus that is far more distracting in quieter spaces - such as the booth in hearing test truck, and most certainly at night.

 

[Xaborus]

I have tinnitus too my friend- not incredibly bad fortunately. I was in Aviation in the military and was constantly around 130-140 dB sound sources. Double hearing protection can only do so much.

Sometimes I play low-level music at night in a bedroom setup to sleep. I also really enjoy listening to some binaural beats in comfortable earbuds when going to sleep. I use "BrainWave 32 Binaural Programs".

I'm sure you know about these white noise generators too, but just in case you don't. I really need to get one for my bedroom.

https://www.amazon.com/Marpac-Dohm-DS-All-Natural-White-Machine/dp/B000KUHFGM

 

[dotneck335]

Not true. If you have a clean signal with a 0 Dbfs sinewave at a given volume output, the amplifier will never clip because digital sound will not be above 0dbfs. This is how car audio enthusiasts tune subwoofer amplifier gain, but usually with a sinewave around -10dbfs.

HUH?? Who T.F. listens to sinewaves? I'm talking about MUSIC!!

 

[Xaborus]

HUH?? Who T.F. listens to sinewaves? I'm talking about MUSIC!!

Doesn't matter if it's music or a sinewave. A digital recording does not exceed 0dbfs. A 0dfbs sinewave can be used to set gains on an amplifier; as the gain is turned up clean power increases- until 1% THD or audible distortion, then backed off until clean.

To simplify the process, the same thing can be done with a 0dbfs sinewave and an amplifier w/ a Volume knob. Play a 0dbfs tone and turn up your volume knob until 1% distortion is reached, then back off until clean. Now any music played at or under this volume knob "maximum" will absolutely be under 1% distortion and will never clip, even if the dynamic range of the music is 30dB. This is simply because a digital recording will not exceed 0dbfs.

Disclaimer: Usually a test tone cd with "0dbfs" sinewave tones will actually be -3dbfs tones, as a true 0dbfs sinewave's peak would then be +3dbfs and clip.

0dbfs = maximum possible digital level

 

[Tom2112]

OK, so I get how adding a speaker will add dB: 3 each. But here's my hesitation to adding two more speakers (total of four) to the setup: won't that draw twice as much power electrically speaking? As in, won't my batteries be drained much quicker running four speakers rather than two, given the same speakers?

 

[Xaborus]

At the same volume, accurately the opposite. You can broadly think of sensitivity as efficiency of turning electrical power into sound. More speakers = more efficient = higher volume at same amplifier power output. You can also think of this as less power to get to a certain volume.

For a car analogy, it's kinda like if you could double the engines and get better MPG for the same fuel at the same speed. Obviously cars don't work this way, but it may help you understand. Believe me, when I was getting into DIY audio, all the technical terminology made my head spin too.

Personally I'd buy a few TC9FD's at ~11 dollars each. 4 of them (two per channel in parallel for a 4 ohm load) will run you around $44, sensitivity around 89.5db before baffle step.

Peerless by Tymphany TC9FD18-08 3-1/2" Full Range Paper Cone Woofer

But hey, feel free to experiment with anything you like!

 

[Tom2112]

Thanks for the explanation, Xaborus. I'm hoping to get a bit better bass response that those speakers will produce, but they sure are a bargain! That makes them tempting.

Another question about two identical speakers per channel: would I need to have separate enclosures for each speaker or would one per channel be ok?