# has any one had a head unit that did not clip at full vol



## wecode420 (Jun 28, 2011)

has any one had a head unit that did not clip with a oscope at full vol 


i was testing clipping with a 40hz tone going out the sub rca 40 out of 40 still no clipping nice round wave

or am i doing something wrong


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## Syaoran (Jun 27, 2011)

wecode420 said:


> has any one had a head unit that did not clip with a oscope at full vol
> 
> 
> i was testing clipping with a 40hz tone going out the sub rca 40 out of 40 still no clipping nice round wave
> ...



I'm not completely certain but most of the time clipping comes from the amp. Check at full volume on your HU to see if your amp's speaker outs clip.


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## Niebur3 (Jul 11, 2008)

HU's can clip, but most have been tested (by members of this forum) to be able to provide an unclipped signal at full volume.


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## wecode420 (Jun 28, 2011)

Niebur3 said:


> HU's can clip, but most have been tested (by members of this forum) to be able to provide an unclipped signal at full volume.


good to know man thx just makeing sure not not ****ing **** up


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## kyheng (Jan 31, 2007)

Most of the reputable brand's HU won't clip.... but if level matching are not done right, it will clip.....


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## Mr. Nice Guy (Jul 21, 2011)

I've got a Clarion CZ500 that does not clip at full volume (40). Taking a wild guess that you also have a Clarion HU, OP?


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## Mr. Nice Guy (Jul 21, 2011)

Syaoran said:


> I'm not completely certain but most of the time clipping comes from the amp. Check at full volume on your HU to see if your amp's speaker outs clip.


Not correct, 90%+ of HU's clip, generally at >90% of full volume, some as low as 80%. It's why most manufacturers recommend setting gains with HU volume at 75% if you don't have an Oscope to actually see where clipping occurs.


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## 95acc (May 23, 2011)

i have scoped a dew of the mid level JVC deck and have no clipping at full volume. Just shy of 2v outout, 
I like to scope every new cd player that we install and most of them have been pretty good.


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## Mr. Nice Guy (Jul 21, 2011)

It also matters greatly what you use for a signal. Make sure you use a 0db sine wave, if you're burning a disc then once you've burned your tones, open the files in an audio editing program like Goldwave or Audacity and verify that they are 0db clean sine waves. Some people use attenuated tracks to set gains, which will can and does cause problems because you'll always have the possibility of exceeding input levels of the signal you used to set gains with. If you use a 0db wave though, you'll never run into this problem.


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## brianhj (Apr 9, 2009)

P99rs


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

This greatly depends on the head unit and brand. I saw a sony clip at 31 out of 50 with a 0db tone. My Denon R-1 didnt clip at all. The new headunit I'll be using supposedly doesnt clip either, the P99-RS


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## huckorris (Sep 2, 2009)

This is a long shot but is anyone familiar with my Alpine 7854? it's from ~2001


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## narvarr (Jan 20, 2009)

The P99RS does not clip at full volume. It has been tested numerous times on this forum by diffrent members.

Sent from my X10i using Tapatalk


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## narvarr (Jan 20, 2009)

Here's a link to one:
http://diymobileaudio.com/forum/showthread.php?p=1346794
and another:
http://www.diymobileaudio.com/forum/member-reviews-product-comparisons/74329-testing-pioneer-carrozzeria-deh-p01-freq-respose-eq-x-over.html

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## ErinH (Feb 14, 2007)

Mr. Nice Guy said:


> Not correct, 90%+ of HU's clip, generally at >90% of full volume, some as low as 80%. It's why most manufacturers recommend setting gains with HU volume at 75% if you don't have an Oscope to actually see where clipping occurs.


Not entirely correct either. 

I've tested a lot of decks the past few years, all from well known manufacturers. None of them clipped. 

I tested them all with a 560 ohm load (ie: much higher resistance than typical amp/DSPs @ ~20kohm resistance on most) using a 1khz, 0dB sine wave. Occasionally I'd test them with a 60hz tone. Not had a single deck to clip yet. That includes a lot of alpine and pioneer decks as well as eclipse, and kenwood. 

the reason mfgs suggest you use "75%" head unit volume has much more to do with giving the listener a bit of headroom on the volume knob for quieter music rather than to keep the user from driving the outputs into distortion.
Besides, if you think about it, there's more room for distortion to enter the equation if an amps output is set to max unclipped with 75% volume rather than maxing the deck because you would then have the extra 25% to drive the amps output even further - in to clipping - more than if you max the deck out and set the amp gain for max unclipped at full deck power. 
Make sense?


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## kyheng (Jan 31, 2007)

^Well said.... That's another reason why a good tuner dare to charge expensive on tuning a system....


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## Mr. Nice Guy (Jul 21, 2011)

bikinpunk said:


> I tested them all with a 560 ohm load (ie: much higher resistance than typical amp/DSPs @ ~20kohm resistance on most)


Why don't you test with a ≤ 4 ohm load?


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## narvarr (Jan 20, 2009)

Mr. Nice Guy said:


> Why don't you test with a ≤ 4 ohm load?


He's using the RCA outputs, not speaker outputs. No rca out on a headunit would see a 4ohm load in normal usage.

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## Mr. Nice Guy (Jul 21, 2011)

Well then if you can't simulate a load close to what the RCA's would actually see, why test at the RCA's at all? Why not test at the speaker outputs on the amp, with gain turned down all the way to isolate HU gain from the amp gain?


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## narvarr (Jan 20, 2009)

Mr. Nice Guy said:


> Well then if you can't simulate a load close to what the RCA's would actually see, why test at the RCA's at all? Why not test at the speaker outputs on the amp, with gain turned down all the way to isolate HU gain from the amp gain?


Because we want to know at what level the HU's output clips, not the amp it's hooked up to. The level at which a HU clips will not change due to having an amplifier hooked up to the outputs. I think he was just trying to get as close to a "real world" scenario as possible in his testing.

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## Mr. Nice Guy (Jul 21, 2011)

narvarr said:


> Because we want to know at what level the HU's output clips, not the amp it's hooked up to. The level at which a HU clips will not change due to having an amplifier hooked up to the outputs. I think he was just trying to get as close to a "real world" scenario as possible in his testing.
> 
> Sent from my X10i using Tapatalk


But testing the RCA's with 560 ohms instead of 20k ohms surely isn't as accurate as testing at the amp, with gains turned all the way down so as to not be testing the amp's output, just the HU's, with a load equal to the speakers, surely that's a much more accurate way to determine if and when something clips, no?

If going for a "real world" scenario, I would think using a 560 ohm load, which isn't even remotely close to that of any real world components, wouldn't be such a good idea. So what am I failing to understand here?


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## narvarr (Jan 20, 2009)

Mr. Nice Guy said:


> But testing the RCA's with 560 ohms instead of 20k ohms surely isn't as accurate as testing at the amp, with gains turned all the way down so as to not be testing the amp's output, just the HU's, with a load equal to the speakers, surely that's a much more accurate way to determine if and when something clips, no?
> 
> If going for a "real world" scenario, I would think using a 560 ohm load, which isn't even remotely close to that of any real world components, wouldn't be such a good idea. So what am I failing to understand here?


Speaker load on the amp has nothing to do with the load on the headunit. If anything, the load he used is more "taxing" than what would be seen in "real world" application.

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## trumpet (Nov 14, 2010)

I don't have much to add but to restate what narvarr and bikinpunk have discussed, the load placed on a head unit's pre-outs is typically tens of thousands of ohms. You don't use a single digit impedance test load because it's never going to see that in the real world.


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## TOOSTUBBORN2FAIL (Jan 31, 2011)

Agreed with bikinpunk. Since each amp has a different input impedance, bikinpunk is overdoing it by using the load hes using. In other words, the lower the impedance, generally the sooner the head unit will clip. By using 560ohms, hes garenteeing that no amp will put more load on the head unit then his test does, basically garenteeing that the head unit wont clip with an amp, before it does on his test.


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## t3sn4f2 (Jan 3, 2007)

Exactly, it's a worst case scenario (if that). Look at any _preamp_ test online from stereophile and those types of mags. They test with the same 600ohm load.


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## 11blueGTI (Apr 24, 2011)

I have had several, from the beginning, CDA-7995, DVA-7996, DVA-9965, Pioneer P9, Pio DEH-p880 and p800.


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## wecode420 (Jun 28, 2011)

bikinpunk said:


> Not entirely correct either.
> 
> I've tested a lot of decks the past few years, all from well known manufacturers. None of them clipped.
> 
> ...


makes alot of sence thx


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## denetnz (Jul 31, 2009)

P99RS doesn't clip at full volume - but does that still that apply at full volume with full eq boost at a given frequency? Has this been tested?


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## IIGQ4U (Aug 8, 2011)

The Alpine CDA-117 also does not clip at full volume.


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## Tweet (May 27, 2016)

Kenwood ddx9907s scopes out with no clipping, but someone please explain this- how is it that the clip indicator on my amplifier shows clipping at volume 26 out of 40? I'm confused....


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