Smd ad-1 vs clamping read before being a smartass please.

[Wicks]

Holy shit, I guess i need to specfiy since we have experts around these parts

I was referring to in a car, amp hooked up to a sub, you willl NEVER EVER FUCKING NEVER have 100% efficiency or a power factor of 1.

WHOA WHOA WHOA lol

..................and you're gonna hate me...................again.

You're 50% right.

Car audio will never see 100% efficiency, but then nothing anywhere has 100% efficiency.

You'll always have some small amount of loss due to resistance (electrical) or friction (mechanical).

BUT in car audio you can see a power factor of 1. Many times actually.

Here is an impedance sweep I did on my actual sub box in my car with my door open:

The red line is the phase angle of the voltage and current to my subs wired at 1 ohm.

Its a normal ported box so we see two impedance peaks along with a dip at the tuning frequency.

I added four green circles at the points where the phase angle crosses the 0 degree line or where the voltage an current are in phase which would be at the points where the system was purely resistive (PF=1).

So from this chart it looks like my system has a PF=1 at ~23.7Hz, ~31.5Hz, ~49Hz and ~84Hz.

Interestingly, so far in my brief testing, my peak SPL frequency is at 49hz.

Also interesting...

I'm wired at "1ohm" yet from real-world measurements I'm only below 2ohms at three small spots:

<15Hz which is obviously filtered out by the subsonic (infrasonic) amp filter.

Between 30 to 33Hz

Between 70 to 107Hz.

Otherwise my "real" impedance ranges from 2 to 12 ohms.

[Bump4life]

very interesting. how do you conduct and graph a sweep like that?

[HunterJohnson]

So far what I've learned from this thread is wicks knows way more than I do

[Wicks]

very interesting. how do you conduct and graph a sweep like that?

With an "LCR" or impedance meter. Inductance-Capacitance-Resistance

It measures impedance at a certain frequency and can sweep through a range of frequency's. Similar to the IM-SG.

It can also measure phase angle which was useful for the info above.

[Wicks]

So far what I've learned from this thread is wicks knows way more than I do

[HunterJohnson]

I just know the impedance meter lol bc I've used it so much. I still don't actually know how to clamp an amp.

I was learning how to set crossover points with a dmm tho!

And the AD I don't know shit about

[Swordlordboy1234]

All I know is this thread has a couple people I'm enjoying reading their info.

I kinda wish I could do a real world test of my car like that.

[fecupe2001]

no way i´m gonna keep getting a headache every time i open this topic, sometimes ignorance is the way to go lol, i get so confused every time one of this awesome guys post here, gonna unfollow the topic now, cheers!

[Wicks]

All I know is this thread has a couple people I'm enjoying reading their info.

I kinda wish I could do a real world test of my car like that.

SMD IM-SG or AMM-1 will get you most of this info.

Don't think they phase angle though, but impedance is probably more important to know anyway as the phase will follow these same patterns so you can approximate.

[Dd9515 king]

So wicks from your statement your amp hardly sees one ohm right. So couldnt you get a bigger amp that does closer to the rms of your woofer at 2 ohms or higher.