Voltages on your Speakers

[Markgm]

Hi,
I'm just curious, looking at basic voltages, amperages, and ohms, and watts, and ohm's law, and wondering what voltages people are actually needing when fully driving their speakers.

I have 5 ohm loads. I think that when they are at their max travel, it is probably at around 70 watts (occurring in bass). The tweeters will go farther, but my ears won't. The woofers are rated at I think 80 watts anyways. When I go for more wattage, like on up to 140 wpc, I think the woofer is going into compression.

If I translate this into wattage, using a 5 ohm load, I think I would be satisfied with 25 volts, 5 amps, into a 5 ohm load, for 125 wpc. This makes me wonder why people go to 30, 36, 40v, or more. It seems to me that amperage is the next thing that will wind up not keeping up with the rise in voltage. For two channels, this also means that I, with 5 ohm loads, need 10 amps for two, or if they were 4 ohm loads, 12 amps for two, at the same level of driver extension and efficiency. (In this case, 87.5 dB/1 watt speakers. I have measured 108 dB SPL from the pair before noticing it going into compression, 65-70 wpc, it seems, for fully extended) And then, with clarity but a little compressed, at 110-1 dB, I would guess at around 125-140 wpc.

As a matter of personal preferences, I think I like having the 3 dB crest past the 70 wpc, or around 140 wpc clean for this speaker. But I don't feel like I need anything past that. It's a vifa woofer and tweeter. The impedance in the audible range is from 4.5 to 5.5 ohms.

Cheers,
Mark

[nigelwright7557]

For home use you dont need megawatts.

I run a mobile disco and need up to 800 watts peak.
This means using high power MOSFET amps and larger speakers.
I use 18 inch bass units to get the low down notes.
I use a full range speaker for the mid to high notes.

[Markgm]

Do you know what your drive units are rated to handle in watts? My tweeters are rated for 30, or 300 some would say, and the woofers for 80. I'm curious.
TIA -
Mark