Clamping my amp 2ND try!!! WHICH TONE MOST POWER?

[XORstatus 10+ year member]

I tried yesterday to clamp my amp to see what type of power it was pushing, NEEDLESS to say I FAILED HORRIBLY, I tried initially with music.

The reading that I got were RETARDED to say the least.

I have since found my shortcoming and I now have a test tone cd.

MY question is, which frequency will entice the amp to produce the most power?

So I can get an accurate reading?

Click to read more...

 

[bubbagumper6 5,000+ posts]

Maybe you should start by describing your test setup...paying any attention to THD or just winging it?

 

[THATpurpleKUSH 5,000+ posts]

Lol you never clamp on music.

 

[mast240 10+ year member]

depends on your set up, really... i've found best for mine around 40-50hz range... but for different set up, different tones will make different results.

and yes, you NEVER clamp on music, lol

 

[dumple 5,000+ posts]

What kinda clamp are we talking here

 

[XORstatus 10+ year member]

SOME interesting results.

I found the maximum output to be around 950w BUT when testing my car dropped to 9-10 volts. YES my car was on.

I have the amp set not to exceed the the mechanical/thermal capacity of my sub, which I assume is in the neighborhood of 1200 +/-.

AVG amps ~ 17 - 18

AVG volts ~ 50 - 55

What do we have to say about this?

 

[THATpurpleKUSH 5,000+ posts]

Looks like you're getting a 3 ohm load after box rise and power is between 850 and 990wrms

 

[XORstatus 10+ year member]

Not sure why resistance increases?

Could you explain this to me.

My sub is wired @ 1 ohm.

WHY IS THE VOLTAGE DROPPING so badly?

I have DUAL runs of 2 gauge wire from the ALT to the battery. (The battery is in the trunk)

I assume this is the culprit of the low wattage.

AND I dint adjust the gain setttings, which is set to about 8'o clolck. REALLY LOW.

BUT I SHOULD BE GETTING MORE POWER THAN THIS!

 

[hispls 5,000+ posts]

A speaker is a reactive load. The actual impedence at any given frequency will vary both free-air and depending on what box and room(or car) the system is in. For the most part your impedence isn't something you can do a lot about for the purpose of daily listening.

 

[XORstatus 10+ year member]

Are you saying that regardless of the wired impedance of the subwoofer, the actual environment manipulates its legitimate resistance?

So a sub wired @ 1 ohm can gain three times, (or even greater) its wired resistance depending on the circumstances and the box it is installed in???

WHY IS THIS? AND WHY DOES SUB IMPEDANCE matching to appropriate amps matter then?

IM PROBABLY JUST NOOBY AND EVERYONE ALREADY KNOWS THIS, so humor me please.

 

[mast240 10+ year member]

One thing you have to understand, is that max wattage is a relative term... as it is constantly changing.... most set ups are lucky to see 70% of rated wattage during majority of play, unless they are running an EXTREMELY efficient box.

for your voltage drop, is that being measured at the amp terminals/rear battery/front battery?

 

[Imtjnotu 5,000+ posts]

what alternator?

 

[THATpurpleKUSH 5,000+ posts]

Your car's electrical system can't sustain the current draw of the amp. If your voltage is dropping that bad you are most likely clipping the ***** out of that sub which is more harmful than over powering it. The amount of runs to the alt and battery are useless if you haven't bothered to upgrade your grounds (part of the big 3) and have a weak alternator.

The impedance changes for every frequency played, when you play music the sub is never operating at the same ohm load. When you check the resistance with a dmm you will see the actual ohm load before box rise. Ex when I wire my subs for 2 ohms, the real load is 1.55 ohms. I don't know enough to explain why box rise happens, but it does affect the amount of power that the woofer sees. In spl you want a minimal box rise as possible to get the most power possible to the woofer.

 

[mast240 10+ year member]

Are you saying that regardless of the wired impedance of the subwoofer, the actual environment manipulates its legitimate resistance?
So a sub wired @ 1 ohm can gain three times, (or even greater) its wired resistance depending on the circumstances and the box it is installed in???

WHY IS THIS? AND WHY DOES SUB IMPEDANCE matching to appropriate amps matter then?

IM PROBABLY JUST NOOBY AND EVERYONE ALREADY KNOWS THIS, so humor me please.

put it in simplest terms i can for you:

as your sub plays different frequencies, the pressure that builds up on the cone increases/decreases... this creates more/less resistance on your coils. thats about as basic as i can get about it, without going into fluid dynamics, and other nerdy things... this is where the term "box rise" came from as well, as a free air sub wont have nearly as much variation in resistance, as an enclosed one... due to the pressures involved inside a box being much greater then free air....

 

[XORstatus 10+ year member]

One thing you have to understand, is that max wattage is a relative term... as it is constantly changing.... most set ups are lucky to see 70% of rated wattage during majority of play, unless they are running an EXTREMELY efficient box.
for your voltage drop, is that being measured at the amp terminals/rear battery/front battery?

The voltage drop was measured at the front cigarette lighter. I use a plugin meter.

I have other multimeters, other than the one i was using to test voltage out of the amp, I could use one of the other directly on the battery in the rear which would probably give a more accurate reading.

The point is not necessarily to be extremely accurate, but to give a good idea of whats going on currently.

what alternator?

I am using the stock alt which is rated 120 A

The amp I have is an AUDIOPIPE 1.5k D which I understand does rated.

I did have Initial jumps of 60+ volts and 20+ amps which is around 1200w which I expected. This ideal furthers my belief that the real problem is the voltage drop, I believe Im suffocating / chocking my amp.

Again I bow to all fo your superiority when it come to these concepts.

If I haven't said it, thank you all for the help, just giving your two cents helps a lot.