Amplifier Clipping at low volumes

ryboto · Post by **ryboto** » Wed Jul 02, 2008 3:43 pm

I've got a Blaupunkt Overdrive 12'' sub being powered by an Eclipse XA2000. The gain is not set high. The car has a new alternator in it also, a 130A model, up from the stock 70A. I guess I never noticed it before, but I could have sworn when I initially tested the amp/sub together I saw no clipping at the volume levels I listen to. Today I went to check it, and I saw the clipping light going off randomly on the amp. Now, the amp is rated high enough to drive the sub, and the Alternator+battery in theory has enough to drive the amp. Where would the fault probably be? I don't really know what to test, and I don't really have much equipment to do in depth tests(just a simple multimeter). Thanks for any help!

Ryan from Ohio · Post by **Ryan from Ohio** » Wed Jul 02, 2008 3:49 pm

I had the EA4000 and I ran it hard to my comps/subs. The clip light is just extra sensitive I think. Mine went off all the time, but I never had a problem. My equipment all survived also. So I guess my point is, if its infrequent and very quick, I wouldnt worry. If its lit up solid or a lot, then turn the gain down.

William from NOLA · Post by **William from NOLA** » Wed Jul 02, 2008 3:51 pm

What kind of battery do you have?

Try letting the battery charge up for a bit before turning on the stereo. It seems to me that it could either be the battery or the regulator on the alternator.

Also, check your ground on the amp. Make sure there is no paint where it is attached and that it is solid.

ryboto · Post by **ryboto** » Wed Jul 02, 2008 3:57 pm

William from NOLA wrote:What kind of battery do you have?
Try letting the battery charge up for a bit before turning on the stereo. It seems to me that it could either be the battery or the regulator on the alternator.
Also, check your ground on the amp. Make sure there is no paint where it is attached and that it is solid.

That's a good suggestion, I'll try running the car for a while without the stereo on. How can I check the regulator on the alt?? The battery isn't all that great, probably should get a new one, it's just the one that was with the car when my parents gave it to me. It's probably very old.

I was considering it was a ground issue, but I checked it again, and I get the exact same voltages in the trunk as I do at the battery.

Ryan: Thanks for your input. The light is infrequent, and they are quick flashes, never consistently on. What you say is reassuring. I'll have to set aside some time and play some of the tracks I frequently listen to loud, and watch the light, hopefully it's as you say, extra sensitive.

William from NOLA · Post by **William from NOLA** » Wed Jul 02, 2008 4:09 pm

It's most likely your battery not being able to dish out what the amp needs. Getting a good battery such as a red top will fix you right up.

loudwagon15s · Post by **loudwagon15s** » Wed Jul 02, 2008 4:17 pm

a new batt, and also upgrading the big three will definitely help a lot.

Bwcad1 · Post by **Bwcad1** » Wed Jul 02, 2008 6:07 pm

if the light just flickers your perfectly fine.

solacedagony · Post by **solacedagony** » Thu Jul 03, 2008 2:36 am

Bwcad1 wrote:if the light just flickers your perfectly fine.

x2, it's perfectly fine to have a clipping light flashing now and then. That usually means you're getting full power out of it. Also, sometimes the clip light is a comparator circuit which doesn't actually indicate clipping. I'll see if I can find more on the circuit sometime today.

Ryan from Ohio · Post by **Ryan from Ohio** » Thu Jul 03, 2008 3:14 am

Since clipping is essentially a square wave, the longer the light stays on the worse the scenario.

Like if it just flicks on and off very quickly every now and then its no biggie. It could be because that track was recorded louder than a previous track. Its just that easy to make an amp clip.

Now if it was blinking like Christmas lights, then you have an issue, turn the gain down.

JeremyC · Post by **JeremyC** » Thu Jul 03, 2008 7:43 am

What your seeing is called gain overlap.

If you set your amp to never clip, your output is going to be crappy.

So you can set your gain a little hot so that you gain more output, but keep clipping to a minimal.

If you check out the auto sound 2000 disc set, they have one for setting gains. It uses 0 db -5 db and -10 db tracks to set your gain using an o-scope, or volt meter. It basically lets you set your gain with a known amount of clipping, while gaining up to 10 db. (it actually goes higher, but I only use those 3)

To give you an idea, 10 db of gain overlap will give you about 9.5 dbs more output, but keeps clipping to were most people won't notice it (below .3% of recorded material)

5 db of gain overlap will give you about 4.5 dbs of more output, and keeps clipping below .03% of recorded material. Very few people will be able to notice clipping at this setting.

0db of gain overlap will never clip, but your output will go to crap. So you need an amp with a buttload of head room.