Saz 3000 at .5 ohms

[fritosaregood 0]

I started running my Sundown 3000 at .5 ohms a little over a week ago, and I figured I'd share my experience with performance in regards to temp of the amp.

Subs: 2 dual 2 ohm audiopulse axis wired down to .5

Electrical: 200 amp alt, one kinetik 1800 under the hood and one kinetik 1800 in the trunk.

Sealed box, 2 cubes per sub, impedence rises over 1 ohm at 18 hz and doesnt drop below 1.1 ohms after that.

Gains on the amp are set with 50volume on the deck as max

Before started I took the temp of the amp it was 62 F

I started playin music on volume 40 for 8 minutes, then I turned it up to 50 for 13 minutes. Total test time 21 mins.

I measured the temp of the amp again:

The side with the power wired was 78.4 F, the side with the rcas was 87.8 F

The A/C wasnt on, outside temp was about 55 F, amp is mounted on a board with nothing above it.

Songs played during the test were:

Chain hang low

Paper Planes Remix

This is why Im hot

Lollipop Remix

Watch my shoes

3 Peat

The subs cone temp were both around 76 F

With this said, I feel comfortable running my Sundown 3000 and .5 ohms daily.

[holley2346 6]

edit: I suck at reading.

Edited April 6, 2009 by holley2346

[Parker 2]

To bad you couldn't try strapping them at 1 ohm.

[cubdenno 0]

I would add another battery at least for reserves. Of course I am a fan of overkill sometimes. Have to let some of the other guys chime in on this. The ones who do this.

As far as output, what did you think? Noticeable over the ported enclosure? Haysoos, It has got to get low. My 1 15 was ridiculous. Your two 15's on double the power has got be earthmoving.

Congrats!!

[bassahaulic 155]

To bad you couldn't try strapping them at 1 ohm.

Diablo and I strapped 2 1500's at 1 ohm. Amps never got that warm.

[jonbearsmt 919]

the tops never got warm or the sides never got warm?

i dont see how 2 amps at .5 ohms could not even get warm.. unless the gain was on min....

[bassahaulic 155]

the tops never got warm or the sides never got warm?

i dont see how 2 amps at .5 ohms could not even get warm.. unless the gain was on min....

Well by warm I mean...... above normal.

and in LA..... it's 80 most the time... haha

[fritosaregood 0]

To bad you couldn't try strapping them at 1 ohm.

If i had another, and two more subs. haha

I would add another battery at least for reserves. Of course I am a fan of overkill sometimes. Have to let some of the other guys chime in on this. The ones who do this.

As far as output, what did you think? Noticeable over the ported enclosure? Haysoos, It has got to get low. My 1 15 was ridiculous. Your two 15's on double the power has got be earthmoving.

Congrats!!

I use to have two 1800s in the trunk and one autozone battery under the hood. but now i have 2 2400s in my garage waitin so i went ahead and put one 1800 up front. my voltage stays up unless i have it full tilt at idle.

For output, i would say it shakes everything more, my car has got some flex back. The lows are nice but compared to my last ported box tuned real low its not as good. But if i had more than 2 cube each it would could get better.

[fritosaregood 0]

Update:

I decide to do another test, but this time with roughly half the power.

Before i started the temp of the amp was 74 F

I played music for 19 mins.

The tempurature this time was 77.5 F on the power terminal side, and 84.8 F on the RCA side. Pretty much the same as the fult tilt test.

So further conclusions are these temps seem to me regular operating temps at this low ohm.

[mattd0344 2]

Update:

I decide to do another test, but this time with roughly half the power.

Before i started the temp of the amp was 74 F

I played music for 19 mins.

The tempurature this time was 77.5 F on the power terminal side, and 84.8 F on the RCA side. Pretty much the same as the fult tilt test.

So further conclusions are these temps seem to me regular operating temps at this low ohm.

Well since impendence rise never goes below 1.1 ohms, in actuality it should perform fine at that load; shouldn't it?

[fritosaregood 0]

Update:

I decide to do another test, but this time with roughly half the power.

Before i started the temp of the amp was 74 F

I played music for 19 mins.

The tempurature this time was 77.5 F on the power terminal side, and 84.8 F on the RCA side. Pretty much the same as the fult tilt test.

So further conclusions are these temps seem to me regular operating temps at this low ohm.

Well since impendence rise never goes below 1.1 ohms, in actuality it should perform fine at that load; shouldn't it?

Thats right. Thats why I noted what my impedence rise was. but most ppl look at non reactive loads. which is the .5 in this case.

[mattd0344 2]

Thats right. Thats why I noted what my impedence rise was. but most ppl look at non reactive loads. which is the .5 in this case.

If you don't mind me asking, how did you measure your impedence rise? I'm kind of interested to see where mine is at.

[Duran 387]

Thats right. Thats why I noted what my impedence rise was. but most ppl look at non reactive loads. which is the .5 in this case.

If you don't mind me asking, how did you measure your impedence rise? I'm kind of interested to see where mine is at.

Hold a DMM to the leads at the amp and play something.

[NB50 206]

Thats right. Thats why I noted what my impedence rise was. but most ppl look at non reactive loads. which is the .5 in this case.

If you don't mind me asking, how did you measure your impedence rise? I'm kind of interested to see where mine is at.

Hold a DMM to the leads at the amp and play something.

You can't measure resistance/impedance with power applied. You have to take voltage and current measurements then calculate it.

[fritosaregood 0]

Thats right. Thats why I noted what my impedence rise was. but most ppl look at non reactive loads. which is the .5 in this case.

If you don't mind me asking, how did you measure your impedence rise? I'm kind of interested to see where mine is at.

Hold a DMM to the leads at the amp and play something.

That way didnt work for me. I think its only dc resistance that does like that,

I did it two ways, first i use a WT3 woofer tester to get an impedence plot showin were it rises to at each frequency. about 100buck. then i used a DMM to measure AC voltage and a clamp meter to find current from 20hz to 70hz, Then i put that in and excel spreadsheet, both ways were very close, my lowest actual rise after 18hz was really 1.097something.

I prefer the WT3 tester, it can test from 1 to 20000hz ,but since it a sub i really only look up to 100hz, in about a second. where as the other way took a while. when i had to get readings, write them, do the math, I let excel do the math for me though

[zfrerichs 0]

so you can use the wt3 to find the box rise? if so can you add a few pics to show how its done?

[fritosaregood 0]

so you can use the wt3 to find the box rise? if so can you add a few pics to show how its done?

Thats what i use it for mostly, it can also find the t/s parameters.

It plugs in to the usb port of your computer.(after you calibrate it with the provided resistor) You just connect it to the pos and neg speaker wires with the gator clips. then hit impedence sweep.

[sundownz 197]

One thing you are over-looking. Real music does not = one sine wave at a time.

http://www.audiograph.se/subpages/technica...odamplifier.htm

"The upper graph illustrates the conventional way of measuring the loudspeaker impedance.

The lower graph illustrates the dynamical approach.

We took a commercial ’off-the shelf’ loudspeaker and did a standard impedance plot for it. We swept the frequency from 20 Hz to 20 kHz, measured the input voltage and current, and calculated the impedance.

However, instead of using a sine wave input signal, we used a square wave. The reason for this is that square waves consist of a large amount of sine waves, as does music. The square wave is of course not an equivalent of music, but for this test it was an easy way of showing that a complex signal (not just a simple sine wave signal) may make the load, from the amplifier point of view, very low.

If you study the graph resulting from the test, you will probably agree that not only is it necessary to check the amplifier’s behavior for resistive, capacitive and inductive loads – the amplifier should also be checked for loads with lower impedance than the nominal impedance of the loudspeaker.

This proves to be very important, since a loudspeaker with a nominal impedance of 4 ohms will sometimes have an actual impedance of 1 ohm or less. The PowerCube helps you perform testing of an amplifier, taking all these load attributes into consideration. "

----

Fortunately for people that run our amps at 1/2 ohm they are robust enough to handle it under most conditions anyway.

[shizzzon 461]

if you want to measure the temperature, you need to take the amp apart.

That would be like measuring the outside of a pc case and sayin it's only readin 5 degrees above room temp and thinkin you are ok.

Same way with the sub. You would need to run a temp sensor up through the vent pole somehow and into the "hottest area" of the design. Preferably, anywhere that will fail first due to heat.

[fritosaregood 0]

if you want to measure the temperature, you need to take the amp apart.

That would be like measuring the outside of a pc case and sayin it's only readin 5 degrees above room temp and thinkin you are ok.

Same way with the sub. You would need to run a temp sensor up through the vent pole somehow and into the "hottest area" of the design. Preferably, anywhere that will fail first due to heat.

I did it that way to show how hot it is to touch, because that is what most ppl use to compare temp for amps and subs.

[rumproast789 0]

what was your voltage lookin like throughout these tests?

[fritosaregood 0]

when im driving, it stays around 14.0~.5, for long bass notes it might drop to 13.5

[jbizzle 1]

when im driving, it stays around 14.0~.5, for long bass notes it might drop to 13.5

I doubt that, especially with YOUR electrical.

I have one hell of an electrical and I'm in the low 13's high 12's on music.

[fritosaregood 0]

when im driving, it stays around 14.0~.5, for long bass notes it might drop to 13.5

I doubt that, especially with YOUR electrical.

I have one hell of an electrical and I'm in the low 13's high 12's on music.

ill post a vid soon and its with a bass test then youll beleive me. What is your electrical

[jbizzle 1]

when im driving, it stays around 14.0~.5, for long bass notes it might drop to 13.5

I doubt that, especially with YOUR electrical.

I have one hell of an electrical and I'm in the low 13's high 12's on music.

ill post a vid soon and its with a bass test then youll beleive me. What is your electrical

Optima yellowtop front, 3 Singer SPV70's rear, Mechman 250a alternator, 2 runs of 1/0.

I'm taking numbers based off my Stinger Volt meter, I could be wrong, because I don't think its 100% accurate. My volt meter on my dash doesn't move a bit.

Edited April 13, 2009 by jbizzle