Finding watts

[Alex K]

I feel like a complete faggot asking this, but id rather be safe than sorry.

American bass 500.1 on a lvl 5 15. elec is in sig, and soon going to run some more xs batts. About 4 more to be exact. My voltage is about 13.3 now at full tilt. I know watts are amps x volts. How can I figure my amps out? My box rise sets me to about 1.4 ohms, and going off this chart http://img28.imageshack.us/img28/2126/rmschartnodirections.jpg im guessing I should be looking at the 1.5 ohm section correct? It's 12:16 am so If I missed something lmk. Just wondering which wattage to look at before I turn it up. Gains havnt really be touched yet. been too busy sealing this bish off from the trunk :x

[HHR Ed]

How do you know your rise?

You would have to have measured your current (amps) Output to know your box impedance rise.

[Alex K]

took the dmm, set it to ohms, then put it to my box leads and it read 1.4-1.5 Maybe im fuckin something up here. Or missunderstanding box rise.

Edited September 20, 2010 by Alex K

[HHR Ed]

took the dmm, set it to ohms, then put it to my box leads and it read 1.4-1.5 Maybe im fuckin something up here. Or missunderstanding box rise.

ahh, That's not how you measure box rise.

You have to play a tone, or range of tones because the data can vary with frequency.

Then you use a DMM set to measure AC voltage, and read the voltage on the speaker outputs.

Also, at the same time you must have a clamp on Ammeter (current meter) set to AC amps and read the current output on the speaker wire.

Multiplying these 2 figures will give you your power output,

Dividing the voltage by the current will tell you the Impedance (box) rise.

[Boon]

took the dmm, set it to ohms, then put it to my box leads and it read 1.4-1.5 Maybe im fuckin something up here. Or missunderstanding box rise.

Yes, you are completely misunderstanding box rise.

p.s. never, ever hook up a DMM set to resistance to a live amp.

[Alex K]

only time i took the dmm to the box was before i put it in the trunk. I havn't messed with gains yet. Thats why im here lol, cause last thing I want to do is fuck this up.

[Boon]

Well yeah... that's not 'box rise' - it's just the DC resistance of your setup. At 1.4 ohms DC I'm guessing your Z (also known as AC impedance) is right around 2 ohms - is the sub a D4 wired in parallel or a D1 wired in series, by any chance?

A '1 ohm' coil usually reads around 0.7 ohms and a '2 ohm' coil is usually about 1.4 ohms - still treat them as a 1 ohm and 2 ohm coil, respectively.

Unfortunately it looks like you're another victim of all the misinformation about 'box rise' all over the forum at the moment.

[Alex K]

Subs a dual 2 dc lvl 5 15" I have 4 strands of 8 gauge, 1 on e ach terminal, fastened to bolts on the box. The +'s connect together, and the -'s connect together. A DMM set to ohms reads 1.4 to 1.5. That's what im confused on. And I somewhat know what you mean by box rise, and I know these 2 are completely different. Just trying how to figure out how m any watts im pushing. Not too sure what other info im missin though.

[HHR Ed]

Subs a dual 2 dc lvl 5 15" I have 4 strands of 8 gauge, 1 on e ach terminal, fastened to bolts on the box. The +'s connect together, and the -'s connect together. A DMM set to ohms reads 1.4 to 1.5. That's what im confused on. And I somewhat know what you mean by box rise, and I know these 2 are completely different. Just trying how to figure out how m any watts im pushing. Not too sure what other info im missin though.

Testing for wattage and box rise is the same test. Just read my comment above.

[Alex K]

Ahh sorry ed didn;t see your comment. Skipped over it somehow. So I need one of these clamp on ammeters as well as my dmm to get the wattage? I'm still confused on where you're saying to put the ammeter. The dmm goes to the speaker outputs, and the other goes around the speaker wire?