Trying to set the amp to exactly 1500 RMS with DMM

[Rashaddd 5,000+ posts]

38.7 volts

Click to read more...

 

[Rashaddd 5,000+ posts]

Awesome, now how did you come up with that?

1500 times ohm load, sqrt of that

 

[Proximity 10+ year member]

you do the square root of (power x resistance) so in this case sqrt(1500 x 1) or 38.7.

 

[jco1385 5,000+ posts]

i couldnt remember that for anything!!

//content.invisioncic.com/y282845/emoticons/mad.gif.c18f003ab0ef8a0d9c27ca78d77a6392.gif

 

[jco1385 5,000+ posts]

don't hook up the speakers.

 

[GlocksRock 10+ year member]

because when the amp is under a load, you already figured out the correct voltage for the power you need at the given resistance, so no need to have the speakers hooked up.

 

[Rashaddd 5,000+ posts]

Crap, I need a new answer then... I'm setting it to 1500, because the amp is 2600 @ 1 ohm, and 1700 @ 2 ohm. Needing to run it at 2 ohm, and wanting 1500 RMS.
So 3000 sqrt.

54.77?

Yes

this is a bxi260(?) I'm guessing? I have one too and also runnin at 2 ohms //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I've always just set it with the subs hooked up, never had an issue

 

[Rashaddd 5,000+ posts]

Awesome that's what I needed to know. My friend has a 2608 and is wanting to run it at 2 ohm and get 1500 RMS (approx). So I run the 50 hz tone, with the head unit at around 75%, and move the gains until they're at 54.77?

yup, technically a 60hz tone is optimal, because that's the frequency your dmm will be most accurate at reading, but it really doesn't matter, I've set with anything from a 35hz tone to a 60hz tone

 

[MikeyB 5,000+ posts]

SQRT(Power x Resistance)

Unhook Speaker

 

[MikeyB 5,000+ posts]

Thanks, good to know. Now we have another question. Our local audio shop didn't wire his 2 ohm dvc subs like this:

Instead, each sub is wired like this, and come out of the box seperately:

So the audioshop didn't wire it like the first image, they instead, wired each sub seperately, and then ran each sub to each speaker terminal on the amp. What ohm load is the amp seeing when it's hooked up like this?

And if my friend were to wire the 2 positives together, and the 2 negatives together, and hook it up to the amp bridged, what ohm load would the amp be seeing then?

Just to mention, we're gonna hook it up right, we would just like to know if wiring it like this changes the resistance at all, or could harm the amp or speakers, because the box has been wired like this for a while, and my friend has gone through 3 amps. I really hope having it wired like this doesn't hurt amps, because if so, this audio shop has cost my friend alot of money...

If its a mono block amp the positives and negatives are the same (its just for ease of wiring), and thus, if I am reading correctly, the amp would see a 2ohm load.

 

[MikeyB 5,000+ posts]

Notice how the images you posted are really the same thing if you have two speakers wired like the second image and connect the positives and negatives together.

 

[MikeyB 5,000+ posts]

Ok awesome that's what I thought. If you connect the positives and the negatives and hook it up to the mono amp bridged (outer positive and outer negative right?) then it will see a 2 ohm load.
What about if you don't wire the positives and negatives together, and just hook each sub up to each terminal (2 positives and 2 negatives on the mono amp), what ohm load is it seeing then? Or is it still 2 ohm? This is how the shop had it set up the entire time, just wondering how it affects things, if it does at all...

Either way you have mentioned it will equate to a 2ohm load. (Its the same thing)

See....on a mono block amp, the terminal where the positives and negatives are, lead to the same place inside of the case. Therefore, whichever positive spot or negative spot you use wont make a difference. They are there for ease of wiring.

If that makes sense.