Enclosure affecting Voltage?

[Boon]

haha box rise effects the ohms not the current the amp will still try to put out the max power it can at that ohm load that its seeing from where the gain is set

Eeek.

Ohms law > you.

Move impedance = less current.

[OldsBoomer]

Eeek.

Ohms law > you.

Move impedance = less current.

i know the law, just the way i understood it is that the amp will try to draw close to the same amount of current just with the ohm changing which causes less power.

Since my peak is 35hz and i rise to 9 ohms at that frequency my amp should be hella efficent right? hmm well it puts out 546.7 watts at 12.9 volts.. now why would i drop that much if i had less current draw?

If im wrong oops

Edited September 22, 2010 by OldsBoomer

[mxman38]

I have a pioneer 42000dvd

orion 5000d @ 1 ohm

Subs read .7 ohms each.

If i turn everything flat and woofer at 0 bass 0 it doesn't get very loud gains all the way down, so no it doesnt turn off, voltage stays aroune 12.5

Amp seems to turn off around 10 volts or if i have volume cranked and i hit the bass Knob, it wont even play for a split second unless i ease into the volume.

Im almost positive its the box, this enclosure just rapes the lows, but my electrical just isnt strong enough.

I orered the powerbastards 250 amp, and im going to replace the battery upfront with a yellow top or something.

Edited September 22, 2010 by mxman38

[bassl0va]

What I meant was that you should re-set the gains with the HU at flat, not just try it. But yeah,that and get a battery.

Edited September 22, 2010 by bassl0va

[Boon]

i know the law, just the way i understood it is that the amp will try to draw close to the same amount of current just with the ohm changing which causes less power.

Since my peak is 35hz and i rise to 9 ohms at that frequency my amp should be hella efficent right? hmm well it puts out 546.7 watts at 12.9 volts.. now why would i drop that much if i had less current draw?

If im wrong oops

Ahh. A quick lesson then

Output divided by efficiency equals input, no matter what the load is.

Say your amp does 1000w into 1 ohm and it's 75% efficient at 1 ohm.

1000w/0.75 = 1333w input

For a laugh we'll say the input voltage (your battery voltage, before drop) is 13.33 volts so you're doing exactly 100A of current.

Now let's say you play a different note and you get box rise to 4 ohms, and your amp does 300w into 4 ohms at eighty percent (stupid 8 0 80 thing) efficiency

300w/0.8 = 375w input

375/13.33= ~28A

So you're doing 72% less current.

Let's say, hypothetically, the old box would rise to 4 ohms from 30-40hz, so you're only pulling 28A and your electrical can keep up, easy. No matter where the bottleneck is.

With the new box, because of changed tuning etc etc, you have a very different impedance graph, and from 30hz-40hz you only have 0.1 ohm of impedance rise, leaving you with a load of 1.1 ohms. So your amp pulls 72% more current than it used to, and suddenly you have voltage drop.

Edited September 22, 2010 by Boon

[mxman38]

ya it seems like when i play upper frequencies it only drops to like low 13's. but as soon as i hit something low the voltage just falls on its face. Thanks for putting some of this into perspective for me.

So basically my box is more efficient therefore it draws more current because my imp. rise isnt much.

[Dub7Banger]

Ahh. A quick lesson then

Output divided by efficiency equals input, no matter what the load is.

Say your amp does 1000w into 1 ohm and it's 75% efficient at 1 ohm.

1000w/0.75 = 1333w input

For a laugh we'll say the input voltage (your battery voltage, before drop) is 13.33 volts so you're doing exactly 100A of current.

Now let's say you play a different note and you get box rise to 4 ohms, and your amp does 300w into 4 ohms at eighty percent (stupid 8 0 80 thing) efficiency

300w/0.8 = 375w input

375/13.33= ~28A

So you're doing 72% less current.

Let's say, hypothetically, the old box would rise to 4 ohms from 30-40hz, so you're only pulling 28A and your electrical can keep up, easy. No matter where the bottleneck is.

With the new box, because of changed tuning etc etc, you have a very different impedance graph, and from 30hz-40hz you only have 0.1 ohm of impedance rise, leaving you with a load of 1.1 ohms. So your amp pulls 72% more current than it used to, and suddenly you have voltage drop.

Reading your posts is so much easier than school

[white4d96]

Reading your posts is so much easier than school

x2.

[mxman38]

im actually suprised it didnt shut my amp off.
3/4 volume Edited September 22, 2010 by mxman38