Bink's Test CD

[Deutscher]

Howdy All,

Dno if anyone has used Bink's Test CD. Anyway, I want to test my Audio System to get the maximum Voltage/RMS for my gear so I know where not to turn it over. I've gotten Track 6 - Log Sweep 20Hz-20Khz. Only problem is ... it's a wave file so I converted it to MP3 format (losing no quality), and put it into MP3Gain... analyzed it and comes up with 104dB gain reading. My normal MP3 collection is set to 89dB gain... When I convert to 89dB (test signal), a normal MP3 song gives more volts than the test tone.

Therefore making the test tone a little useless, I'm sure that's not meant to happen. Can someone shed some light onto why this could be happening? The only thing I've changed is the .wav to .mp3 and decreased the dB to the same as my other songs.

The only other thing I can do, it hook up my volt meter and make it show max ... just run all kinds of music through it and get a max reading ... only problem is that that'll take a long time.

[daron]

just remember if you play that wave 3 times in a row you'll fry your tweeters and smoke them
smells nice

umm why did you make it mp3
why did you five it DB gain
that really defeats the test theory

get a db meter /termlab and test for box frequency then you can work out you best bass and stuff
never use mp3s as a base test tone but silly really
and at the end of the day if ya only pumping 120 db or less (most cars wouldnt get this)
just set ya system up to sound Nice not pump max volts/watts cause that means nothing if its distorted

[StoneX]

Burn the wave file as an audio CD, don't convert anything.

[Deutscher]

Burn the wave file as an audio CD, don't convert anything.

That's pretty straight forwards response. But why shouldn't I normalize it? My music is all normalized to 89dB and the wave file is ~104dB... wouldn't that give the wave file more voltage than the music? giving it wrong information?

[Deutscher]

just remember if you play that wave 3 times in a row you'll fry your tweeters and smoke them
smells nice

umm why did you make it mp3
why did you five it DB gain
that really defeats the test theory

get a db meter /termlab and test for box frequency then you can work out you best bass and stuff
never use mp3s as a base test tone but silly really
and at the end of the day if ya only pumping 120 db or less (most cars wouldnt get this)
just set ya system up to sound Nice not pump max volts/watts cause that means nothing if its distorted

When I test my speakers I disconnect all my speakers. So I don't fry anything I know these test tones are Incredibly dangerous. I just want to know what not to turn the head unit over too keep myself from powering the speakers over their rated rms (I know distortion still places a role but.. it's a starting point)

[StoneX]

That's pretty straight forwards response. But why shouldn't I normalize it? My music is all normalized to 89dB and the wave file is ~104dB... wouldn't that give the wave file more voltage than the music? giving it wrong information?

If someone has made the test file, it should already be made properly and not need modifying. A wave file is raw audio, like a CD rip, so burning it back would be putting the exact data onto the CD that was intended by the creator of the test file. Being 104dB you'd know that you'd have quite a margin of protection when you do play your 89dB files.

Are you saying you're measuring your voltages without speakers connected? You know that your speakers put a load(resistance/impedance) on the amp which changes the output voltage? You need the speaker connected to get the correct voltages.

Really, you should use your ears to gauge whether you're running your equipment too hard, don't rely on a specific volume level on your head unit.

[Deutscher]

If someone has made the test file, it should already be made properly and not need modifying. A wave file is raw audio, like a CD rip, so burning it back would be putting the exact data onto the CD that was intended by the creator of the test file. Being 104dB you'd know that you'd have quite a margin of protection when you do play your 89dB files.

Are you saying you're measuring your voltages without speakers connected? You know that your speakers put a load(resistance/impedance) on the amp which changes the output voltage? You need the speaker connected to get the correct voltages.

Really, you should use your ears to gauge whether you're running your equipment too hard, don't rely on a specific volume level on your head unit.

Ah crap... didn't actually think of that. So how would I go about testing it then? how do I connect the postive n negative of voltmeter to a speaker? would I connect it to the speaker terminals not touching the speaker wire?

[holdenboy]

Im with Stone X on this one, you should use your ears other than a digital meter etc to figure out whether your speakers are distorting.

[Deutscher]

Im with Stone X on this one, you should use your ears other than a digital meter etc to figure out whether your speakers are distorting.

meh.. I don't trust my ears that's why I prefer to trust technology.

[holdenboy]

Just take it back to Alberts then with a couple of your CDs and get them to tune the system again.

[Deutscher]

Just take it back to Alberts then with a couple of your CDs and get them to tune the system again.

Thx Holdenboy, but would you know where to hook up to check the voltage anyway? kinda wanna test my DJ setup aswell ... just want to run ~400wrms into them. It's a little too hard to move my gear to someone to tune it for me.. involves too much moving around and my cabs don't really fit a standard car.

[holdenboy]

Dont know too much about using a DMM to test for voltage etc, what i use is an oscilloscope, which shows up the signal as a wave, a non-clipped signal will have sharp points at each tip of the waves, cliiping is shown by a flattened tip on the wave....its a fool proof way to ensure you amps are not clipping (distorting) when at a certain level.

Very handy whens it comes to SPL hence why i have access to one

[Deutscher]

Dont know too much about using a DMM to test for voltage etc, what i use is an oscilloscope, which shows up the signal as a wave, a non-clipped signal will have sharp points at each tip of the waves, cliiping is shown by a flattened tip on the wave....its a fool proof way to ensure you amps are not clipping (distorting) when at a certain level.

Very handy whens it comes to SPL hence why i have access to one

They seeem a bit pricey well I got my MP3Gain to show clipping (it's not perfect but shud b something), a voltmeter will give a voltage which you convert to RMS. I've also got Patchmix, a software for my recording soundcard which shows a peak meter and also a main mixer level (shows if clipping), so I don't think I'm clipping ... from the computer anyway .. only thing I can do with the amp is get a voltage reading on the speakers and make sure it doesn't go over their rated power.

[holdenboy]

The speakers will handle above their rated power in my opinion, ive fed 2000wrms in 300wrms subs for over 6 months without a drama, and ofcourse the front splits which are getting well over double what their rated at. Its common practice to overpower speakers/subwoofers......as stated in a car audio magazine by a very respected long time car audio expert....."far more speakers are blown from underpowering them as opposed to overpowering them". As ive said before, clipping is what kills speakers, not power. You can measure how much rms wattage is going to the speaker all you want.....but just because they are receiving their rated input power dosent mean their running at their full potential, not by a long shot.

Power given is just one of many factors to take into consideration when asking yourself "are my speakers running at their full potential". Installation is another factor, as is tuning.