Max Unclipped Volume?

[Gas Is Expensive]

I have the F700BT running to my 3Sixty processor which then splits the signal up to my amps. I'm trying to set the levels properly, but I don't have an o-scope to see for certain at what volume level the head unit begins to clip. Max volume is 62.

 

Normally, in a situation like this, I would just set the HU's volume to 3/4 max (~ 46) and do the rest by ear, but at 3/4 volume I can't get the 3Sixty's clip indicator to blink red (the ideal level for the 3Sixty is where the red clip indicator is on the brink of solid red (blinking).

 

Has anyone properly tested this HU for clipping? Is max volume safe?

 

Thanks.

[lromoda]

Cheap but effective way of setting levels. Buy yourself a Radioshack Mini Amplifier Speaker Cat. NO. 277-1008C

 

Play a test tone CD at 1kz with the preamp out plugged into the hand held amp speaker. 1KHz is a good tone to use because its super easy to hear when it transitions from sine-wave to clipped. Set the volume barely audible on the Radio shack unit to make sure you don't clip the hand held's output. We are after input clip from the headunit.

 

Turn up the volume on the Headunit until you hear the tone change to clipped. If you can go full volume without it clipped, great. Mind your EQ settings.

 

Now go to the output of the next component in line and repeat the process and on down the chain until you get to the amps. The amp gain setting is where to decide how much output clipping to allow. If you set up a system that is impossible to clip the output, you will have a quiet system. The key is to not allow any signal upstream of the amp to clip.

 

Important note: EQ settings could take you over the threshold of clipping the signal. If you have 12dB of boost at 40hz, that won't show up in the 1KHz tone test.

[hellodave]

I've scoped my F900

 

Using a 1KHz 0db test tone, flat EQ, SLA on 0 and no bass boost, the unit doesn't clip at volume 62. BUT as soon as you add any boost to the EQ (or change bass boost or SLA settings), it does start to clip. Personally I would use 60 as max volume, to give yourself a little bit of leeway.

 

When I measured it, volume 62 gave the full 2v output, and 58 gave around 1v, which is normal line level IIRC - volume 46 will be very low in comparison. I suspect the 3sixty will cope with input voltages from about 1-5v, which covers almost all head units out there. I'm planning to connect my F900 to the aux input of another head unit/processor, which accepts normal line level signal only (i.e. 2v is too high) - volume 58 worked very well when I tested it all

[Gas Is Expensive]

Thanks for the responses guys. I actually ended up settling on 60 as my max volume setting before reading this (I leave the volume on the unit set to 60 and use the 3Sixty's volume knob as my master volume control). I had suspected that the unit wasn't clipping at the full 62, and I don't use any of the HU's EQ functions anyway, as all of those duties are handled by my external processor.

 

I would, however, like to retune my setup using the unit's full 2 volt output at 62. The only concern I have is that you say the unit will begin to clip using the SLA feature. For whatever reason, the clowns over at Pioneer didn't bother to fix the fact that CD playback is significantly louder than all other sources when they released v2.0.

 

Have you tested for the clipping point of the SD reader? I'm wondering if it's safe to bump up the SLA to +4 (which is STILL not level-matched with the CD player) on just the SD and Sirius sources. I guess I can always try that Radio Shack test. Perhaps I will.

 

Thanks again guys.

[Gas Is Expensive]

I've scoped my F900

 

Using a 1KHz 0db test tone, flat EQ, SLA on 0 and no bass boost, the unit doesn't clip at volume 62. BUT as soon as you add any boost to the EQ (or change bass boost or SLA settings), it does start to clip. Personally I would use 60 as max volume, to give yourself a little bit of leeway.

 

When I measured it, volume 62 gave the full 2v output, and 58 gave around 1v, which is normal line level IIRC - volume 46 will be very low in comparison. I suspect the 3sixty will cope with input voltages from about 1-5v, which covers almost all head units out there. I'm planning to connect my F900 to the aux input of another head unit/processor, which accepts normal line level signal only (i.e. 2v is too high) - volume 58 worked very well when I tested it all

 

Yeah, the 3Sixty actually accepts input voltages from 1-20v. You indicated that the head unit puts out 1v at 58. That makes perfect sense to me, because the 3Sixty requires at least 1v to get its clip indicators to begin flashing, and I had to turn the unit all the way up to 58 in order to get it to do so.