what happened??!!

eulogious · Post by **eulogious** » Wed Apr 28, 2010 11:50 am

stipud wrote:Odds are that this will be much quieter than where you set them previously. Benefit is, if you crank your bass music, you won't blow anything.

Quote of the day for sure!!

reallyxxxxxxloud · Post by **reallyxxxxxxloud** » Wed Apr 28, 2010 4:56 pm

stipud wrote:If you don't want to blow subs then make sure your amp doesn't clip. If you don't want your amp to clip you have to set the gains properly. One of the ways to do that is set them with a multimeter and test tone.

All you need to do is play a 60Hz tone at 3/4 deck volume, all equalization disabled, and with no speakers connected. Then measure for sqrt(1200*4) = 69.28 volts A/C at the amp outputs. Leave bass boost off, forever. Odds are that this will be much quieter than where you set them previously. Benefit is, if you crank your bass music, you won't blow anything.

OK now what about the difference in recording levels with CDs these days. A CD with a proper 0db recording level will play as per your setup but a CD recorded at 15db with compression will throw this all out the window!!!

I'll agree yes the system should be set up like how you explained to begin with but that still doesn't show the customer how to listen for clipping.

Here's what I have shown to customers in the past...

To find max safe volume of a CD or track. Turn or rock volume up and down. You'll soon find a spot where the sound ramps in volume quickly. Just before this ramp is you max volume, its just before adding in Clipping/distortion. Clipping/distortion will add volume quickly. Try this with a CD for those with a test bench and a scope. You'll see I'm right. Any knob weather or not they know what distortion is, can understand this simple test.

Post by **Eric D** » Wed Apr 28, 2010 6:14 pm

Clipping won't add volume quickly. Depending on what kind of music or signal it is, you might not even be able to hear it.

waynehead · Post by **waynehead** » Wed Apr 28, 2010 6:18 pm

the reasoning for setting at 0 db is because 0 db is as high as it gets. most recordings dont get all the way to 0. good recordings do in the dynamic peaks. i mean i kow you can encode mp3s and shit aboove 0 db but all that is is compressing it and most times distorting the recording. i dont understand why anyone would want to do that.

kinda defeats the purpose of putting together a great stereo.

well let me edit this, good recordings get close to 0 at peaks. i dont think it is practiced much to push 0. probably something like -3.

waynehead · Post by **waynehead** » Wed Apr 28, 2010 6:24 pm

I know personally that 100 watts worth of music per channel in my face is more than enough even on the most dynamic tracks.

schroedes · Post by **schroedes** » Wed Apr 28, 2010 7:01 pm

All I listen to is satellite radio, is there any way to test this amp on my old rsdc?

Post by **stipud** » Wed Apr 28, 2010 7:22 pm

schroedes wrote:All I listen to is satellite radio, is there any way to test this amp on my old rsdc?

Sure, hook it up but keep the gains low.

reallyxxxxxxloud · Post by **reallyxxxxxxloud** » Thu Apr 29, 2010 12:15 am

Eric D wrote:Clipping won't add volume quickly. Depending on what kind of music or signal it is, you might not even be able to hear it.

My point is with anyone who has no idea this is a good reference. And doing this by backing back just before the volume ramp will save your system (even if there's some clipping should not damage your system).

waynehead
This is an example of what I was meaning. I was being over the top with the +15 but what I meant was the recording is boosted above 0db so anything above 0db gets compressed. It actually really common practice these days and is done for louder radio playback...
This is a good example of what I was meaning, Metallica's new CD and the difference between that and the version on GHIII.

The yellow is the retail CD and the pink is the GHIII version. Oh the song is "The Day That Never Comes". Visually, the difference is obvious. Once the drums come in, the audio level is practically pegged at 0dB for the rest of the song. There are no more dynamics to be had.

Sure, it’s a metal song. Maybe it’s just really that loud, you might be thinking. But no, the Guitar Hero mix shows plenty of dynamic range. And, not to spoil the surprise, it sounds a lot better too.

To be clear, the core problem with the Death Magnetic CD is not that it’s loud. The problem is that it sounds like crap

Post by **stipud** » Thu Apr 29, 2010 6:51 am

The problem with compression is that it doesn't go away when you lower the volume either. If the music is clipped, it will be clipped no matter what the volume. I still think if the amp is properly set up with 0dB gain it should handle this fine. PG amps tend to clip soft, so as long as you're not pushing the amp's physical power boundaries, it should be fine.

Post by **Eric D** » Thu Apr 29, 2010 8:46 am

stipud wrote:The problem with compression is that it doesn't go away when you lower the volume either. If the music is clipped, it will be clipped no matter what the volume. I still think if the amp is properly set up with 0dB gain it should handle this fine. PG amps tend to clip soft, so as long as you're not pushing the amp's physical power boundaries, it should be fine.

I agree 100%

schroedes · Post by **schroedes** » Thu Apr 29, 2010 9:21 am

Thanks guys, will give her some power in free air

gridracer · Post by **gridracer** » Thu Apr 29, 2010 3:03 pm

I was gonna bring up the metallica / metallica GHIII difference in recordings but still going to add that the retail version sounds like crap no matter what volume you have it on because it starts as compressed distorted recording just like stipud is saying.

waynehead · Post by **waynehead** » Fri Apr 30, 2010 2:40 pm

yeah i have heard the difference myself with the death magnetic album. i just misunderstood really*loud. Hows da fuck do we get these record companies to quit with all the compression. I would imagine that sacd's and blueray audio are not plagued by the loudness issue but im afraid that when they become more mainstream they will be. i cant wait till a new medium moves into car audio. cd's are good and all, but sacd's came out years ago.