Help with multimeter readings...

[Rkrajnov 10+ year member]

Ok so I just received my sub back from repairs a few days ago and put it back in. I wanted to be careful not to blow it again so I set everything with a MM using ohm's law. I got the appropriate voltages (34.6 volts for my Audioque 1200d sending 1200 rms at 1 ohm to my 12" Fi Q and 24.6 volts for my JL 300/4 sending 150 rms at 4 ohms bridged to my Hertz HSK 165s... I believe these values are correct).

Anyways, my logic was that I could probably play some music today and see what voltages the amps were hitting under a lot of pressure. So first I put on a few heavy bass songs and my sub amp was hitting max around 32 or so volts, so I figured this is good, maybe even a little breather room (though I'm no expert with this but I tested the old settings I had the sub at and they were hitting in at like 60 volts so I figure I should be pretty safe where I'm at). Then I tried testing the speaker amp, but for some reason I couldn't get it to produce more than 4 volts or so even though the speakers were blasting. Is this just because of the fact that the tracks are playing all kinds of different frequencies or what (as compared to the test CD I used to set them)? Also does my sub have some breather room and possibly even room to turn it up a tiny bit with the headunit? I only bring this up because I was giving it WAY more power before and it still lasted a good 8 months and I heard that Fi Q subs can handle up to about 1500 rms, but I'm sure my logic is flawed somewhere in wanting to increase the output of it even more, even if I do it via the headunit. I'm far from a car audio expert, I'm just trying to get a grasp on everything and still learn more things every day. Any help is appreciated.

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[sacsking916 5,000+ posts]

Music is dynamic so the frequency change changes the volts from your DMM. as you saw. as long as you set it with the correct tones then you will be fine

 

[Rkrajnov 10+ year member]

Music is dynamic so the frequency change changes the volts from your DMM. as you saw. as long as you set it with the correct tones then you will be fine

ya I understand that, but what I'm saying is where the sub amp was hitting around the volts i set it at with the test tone when it hit loud parts, the speakers never moved past like 4v (at any point in the song). I don't know I was just confused as to why.

 

[keep_hope_alive Premium Member]

Just shows you how little power is necessary for speakers to be loud, and how our ears are much less sensitive to low frequencies.

This is why I ignore posts asking about matching amps to speakers, it really doesn't matter. No one gives 50W to a full range speaker while listening to music.

 

[Rkrajnov 10+ year member]

Just shows you how little power is necessary for speakers to be loud, and how our ears are much less sensitive to low frequencies.
This is why I ignore posts asking about matching amps to speakers, it really doesn't matter. No one gives 50W to a full range speaker while listening to music.

gotchya. I wasn't sure if the readings were erroneous or what. I was kind of shocked at how little voltage was being sent and I wanted to make sure I wasn't being stupid and end up blowing something lol.

 

[Moble Enclosurs 10+ year member]

Very true. I give my front stage around 11 watts per channel. Its plenty.