Not getting 1000 watts out of my SAE-1000D

[themerc 0]

I did some testing today. I got out my craftsman DMM/clamp and played some 50Hz tones.

(I have a Panasonic headunit with 2V preouts, an Excessive Amperage 250A alternator, 1 Duralast Gold size 65, 2 Kinetik HC1800's, big three with knukonceptz 1/0 gauge, etc...)

This is my gain right now (red dot indicates)...

I did volume 30/40 and sub at 0 on the headunit playing a 50Hz tone. I got 28.6 volts (AC) at the speaker terminals and 19 amps (AC) on the speaker wire, so 543.4 watts. I did volume 32/40 and sub at 0 on the headunit playing a 50Hz tone and got 33.2 volts and 21 amps, so 697.2 watts. I measured the resistance on my sub wires... 1.0 ohm. What's the deal? Why am I only getting 500-700 watts?

[///M5 2,833]

Why are you at 30 of 40? Measure the output of your deck and see how few mV's you are outputting...

[themerc 0]

Why are you at 30 of 40? Measure the output of your deck and see how few mV's you are outputting...

Hate to sound stupid, but how do I do that?

[ford302redneck 15]

Where are you from?

[themerc 0]

Where are you from?

NE Florida, why?

[Tirefryr 1,742]

What frequency is the amp measured at from the factory? That's going to be your biggest issue I feel. Most amps are rated at 1KHz, but being this is a class D amp, I have no idea what it's tested at. That, and I'd bet your preout voltage is nowhere near 2 volts, and if it is, it also is probably at that 1KHz rating.

[themerc 0]

I'm giving the amp 13.95-13.98 volts with the engine running.

[ford302redneck 15]

Where are you from?

NE Florida, why?

There was a reason, but it dont matter now.

Your also, only rising a half of a ohm.

So your doing ~650rms at 1.5ohms.

Which is a little shy of what I think it should be doing.

But also it does ~1000rms at EXACTLY 1ohm at 14.4 volts.

The couple tenths of volts, and rise is hurting your I assume.

[///M5 2,833]

Why are you at 30 of 40? Measure the output of your deck and see how few mV's you are outputting...

Hate to sound stupid, but how do I do that?

Measure it at the RCA. Regrettably to find out how far you can turn up your outputs on your headunit, you are going to need an Oscope not just a DMM.

[Tirefryr 1,742]

That's good to know, but your input voltage on the AC side is the problem here obviously. The AC input (signal from your RCAs) is what is being amplified. Your gain should ultimately be matched to this signal for optimal performance and to extarct the most power out of the amp without clipping.

[ford302redneck 15]

What frequency is the amp measured at from the factory? That's going to be your biggest issue I feel. Most amps are rated at 1KHz, but being this is a class D amp, I have no idea what it's tested at. That, and I'd bet your preout voltage is nowhere near 2 volts, and if it is, it also is probably at that 1KHz rating.

Jake doesn't rate his amps using 1KHz, I don't think.

[Tirefryr 1,742]

Also in order to get a verified measurement, you have to have a TRUE RMS clampmeter, as well as a resistive (IIRC) load on the amp. Sean, correct me if I'm wrong on load type.

[themerc 0]

I have this clamp meter... http://metersupport.com/manuals/73756.pdf

[ford302redneck 15]

What are the other settings on the amp?

SSF?

LPF?

BB?

[themerc 0]

What are the other settings on the amp?

SSF?

LPF?

BB?

ssf... 1/4 turn up

lpf... 1/2 turn up

bb... all the way down

[ford302redneck 15]

What are the other settings on the amp?

SSF?

LPF?

BB?

ssf... 1/4 turn up

lpf... 1/2 turn up

bb... all the way down

Try turning the SSF all the way down.

Also, What drivers are you using, and box?

[themerc 0]

One Fi Q15 with BP Power in 4 cubes @ 32Hz with 58.5 sq. inches of port. Turn the SSF all the way down and try playing?

Edited March 16, 2008 by themerc

[shizzzon 461]

do NOT do that and leave it like that!

You are doubling impedance rise which is typical.

DCR is 0.7 ohms, your measurement of 33.2v and 21 amps = 631w @ 1.58 ohms

This may be a signaling issue with the gain matching but also it depends on how the graph looks on an o-scope. If the wave is not filling the screen from top to bottom then you are not getting full potential, but also do not clip or that is bad as well.

You will ALWAYS have impedance rise on every frequency and this rise will be different from one note to another.

This is why people can claim to run thousands of watts to a single sub.... because they are NOT. They are using amps that have the "potential" to but are not due to rise.

Now, i'm sure this amp can do what it's rated but to get that, it's very hard.

When wiring an amp and sub together safely, that means choosing a sub that can safely be wired to an amp without ever going below it's stable rating, you will usually never see it's maximum rated wattage.

Dual 2 ohms subs in parallel are usually either 0.7, 0.75, 0.9 ohms.

Even at 0.7, rise will be above 1 ohm so no trouble in safety there but will be above 1 ohm, not 1 ohm so output will be less than rated spec.

That's just how it is.

Now, you could run 2 dual 2 ohms, which depending on RE per coil, wired in parallel could be 0.35, 0.375, 0.45.

Since rise can be as low as less than double what it is at DCR, you can see that even 0.45 DCR would not be practical for daily!

You have to wire safely but in doing so will keep the rise above it's lowest stable resistance resulting in not full output according to specs.

This is typical for all amps except for some newer ones who use crown or crown-like technology where resistance is more forgiving to retain same output power and power supply is regulated.

Edited March 17, 2008 by shizzzon

[ford302redneck 15]

Try playing a lower frequency, also.

But like stated above, don't leave your SSF all the way down. Just do it while testing.

[themerc 0]

Alright, so basically, to get full potential I need to buy an o-scope.

[shizzzon 461]

u have an o-scope, you can set your gain perfectly, the way it should be.

To get maximum potential, just crank everything up to max and leave SSF down but don't do that if you like your equipment,

To get maximum CLEAN potential, then get an o-scope. Anything beyond that, not wise, not cheap, and not warranted.

the one i bought a long time ago was on Parts Express. It was a Velleman. Works perfectly for this scenario.

[themerc 0]

the one i bought a long time ago was on Parts Express. It was a Velleman. Works perfectly for this scenario.

$195 on partsexpress... I sure hope I upgrade down the road so this isn't a waste of money lol.

[shizzzon 461]

the reason i bought mine when i did was because i was blowing my rear speakers every 4 months. After the 3rd pair got damaged i bought one. Havent had anything get damaged in years since.

[loudcav 1]

accualy your subsonic is set too high and you low pass needs to be turned down a hair then you need to properly set your gain. also if I remember right the frequency that Jake measures power at is 60hz

[themerc 0]

accualy your subsonic is set too high and you low pass needs to be turned down a hair then you need to properly set your gain. also if I remember right the frequency that Jake measures power at is 60hz

That's weird... that's what Jacob told me to set them to...