# Pioneer Class-D noise floor issue? What do you think?



## toylocost (Jul 4, 2011)

I've been having problems with amp turn on/off pop and a hiss, finally took the amps out of the car again and made this video to show you guys the problem. What do you think?


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## toylocost (Jul 4, 2011)

Are we not allowed to embed videos? It works in the post preview...

EDIT: Fixed...


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## thefordmccord (Oct 18, 2012)

I am having the exact same problem with my pioneer amps. I'm convinced they are junk. I am already searching for something different.


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## toylocost (Jul 4, 2011)

Are you using a relay to turn them on?


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## thefordmccord (Oct 18, 2012)

I have tried using the remote on the head unit, the acc from the key, a 30 amp relay and I have tried one of these delays: http://www.amazon.com/PowerArt-Swit...TF8&qid=1437477789&sr=8-2&keywords=n555+delay 

Still had turn on/turn off pop/thump.


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## Victor_inox (Apr 27, 2012)

toylocost said:


> Are we not allowed to embed videos? It works in the post preview...
> 
> YouTube - New Pioneer class-D amplifier noise issue - GM-D9601 and GM-D8604






 you just copy part of youtube url after = then click youtube icon in reply window and paste between tags.


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## toylocost (Jul 4, 2011)

Victor_inox said:


> you just copy part of youtube url after = then click youtube icon in reply window and paste between tags.


Thanks...


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## sirbOOm (Jan 24, 2013)

thefordmccord said:


> I am having the exact same problem with my pioneer amps. I'm convinced they are junk. I am already searching for something different.


We don't seem to have problems with these amps... that blows.

If you want to consider another budget amp, look at PPI yet?


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## toylocost (Jul 4, 2011)

sirbOOm said:


> We don't seem to have problems with these amps... that blows.
> 
> If you want to consider another budget amp, look at PPI yet?


I was looking at the PPI before I bought these but they just looked cheap.

I'd rather have working Pioneers if that is a real thing since I've spent so long building the amp rack and installing everything. I still have the problem with my money being in these, I can't afford to buy something else. I should probably call Newegg and see what they say. I'd be willing to try new amps maybe with a different manufacture date but would they exchange all three? Probably not.


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## toylocost (Jul 4, 2011)

Well I just checked my buddy's 9601 and same problem. His doesn't pop loud enough for him to notice through the trunk so he doesn't care. Maybe I can just hear it better with my trunk baffle....

So, who wants to buy some nice almost new in box Pioneer amps???


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## cajunner (Apr 13, 2007)

soft start remote turn on is a thing...

and for turn-off pop, I think the use of a cap to keep the amps energized for a couple seconds after everything else is off, might do the trick?


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## JimmyDee (Mar 8, 2014)

Ya, that's pretty bad... the noise floor (hiss) is high, even with the gains at the lowest setting. You shouldn't hear anything at that level.

Unfortunately, I don't have a solution, other than to suggest you need to return these amps and get something different. These ones are no good...


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## toylocost (Jul 4, 2011)

Well I called Newegg and they said I should have a one year warranty through Pioneer, called Pioneer and they told me I could take it to a repair shop, suggested Paradyme out here in Sacramento, didn't know they did repairs. I took the amps out there and told the guy my problems, he made it seem as if the repair wouldn't be a big deal so that's cool. We'll see what happens, I'll call him in a couple weeks...


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## toylocost (Jul 4, 2011)

Got the amps back yesterday after 2.5 weeks. Invoice says he soldered a connection in the 9601 and replaced the main board in both 8604s. I can't see how that is cost effective at all considering the MSRP of that part is similar to the MSRP of the amp.

I've tested all three amps this morning and nothing has changed! Awesome!

Invoice for the 8604s says "popping when power turned off will be an additional issue not with this unit", "install issue not with this unit". Also, "replaced defective amp board, checked all functions OK"

The pop and hiss is still there and I think louder than before but I can't prove that.

I've taken pictures of all the amps, you can see on the 8604s he dated the board swap. I don't have pics inside the amps before the work unfortunately. Here are the 8604s...


















And the 9601, even though I can't find where he soldered...


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## toylocost (Jul 4, 2011)

I guess I will call him on monday and ask what he thinks the install issue would be even though I've had them on my bench doing the same thing.

Also forgot to mention he noted that the "EQ needs adjustment via customer", I don't know what that has to do with anything unless he is talking about the gains or crossovers on the amps since it does it with no input. Noise is still there with gains all the way down and I leave crossovers off so that the DSP can handle it. I think the pop is loud enough to damage the tweets if I didn't have a protection cap on them.


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## toylocost (Jul 4, 2011)

So I called him this morning and he told me that when he first powered it up there was audible distortion with music. Which is not the problem I brought them in there for but when the woman at the counter is writing the work order and I can't explain anything to the tech idk why I expected that the message would make it's way to the tech clearly. Doesn't matter anyways since he probably wouldn't have done anything if he knew what I was talking about.

In the end he said he could barely hear it and that he didn't think it was a problem and that I could try a remote delay start. (My DSP has one built in that I was using) Then he sent me up front to talk with one of the installers, really cool asian dude wish I could remember his name. He didn't believe me that it would hiss even without RCAs connected and hooked it up on his bench so he could hear it too. He laughed at me when I told him to put his ear to the speaker saying "all amps do that!". Not sure I believe that all amps produce a hiss but I can't prove otherwise.

We talked for a while and he told me that I should try having the head unit turn the DSP on and then having the DSP turn a remote delay on which would turn the amps on. Still I am skeptical but have no other options at this point and I'm going to order a delay and give it a shot. As long as the hiss is not audible on volume level 1 and I can get the pop to a minimal level I should be able to live with it. Fingers crossed!


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## gstokes (Apr 20, 2014)

toylocost said:


> I've been having problems with amp turn on/off pop and a hiss, finally took the amps out of the car again and made this video to show you guys the problem. What do you think?


That's a ridiculous amount of hiss, I would have to say those amps are junk..

PPI Black Ice would be my choice for replacement..


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## Makky (Nov 15, 2014)

toylocost said:


> I've been having problems with amp turn on/off pop and a hiss, finally took the amps out of the car again and made this video to show you guys the problem. What do you think?


I have a Pioneer 8604 and have not come across this issue.
Could it be you have a faulty unit?

I have a JBL 751 monoblock where this pop thing happens but It started after I had to fix a problem with a new relay wiring.


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## toylocost (Jul 4, 2011)

gstokes said:


> That's a ridiculous amount of hiss, I would have to say those amps are junk..
> 
> PPI Black Ice would be my choice for replacement..


Haha you're just looking for someone to try them out before you buy them!


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## jtaudioacc (Apr 6, 2010)

with nothing else connected, head unit, dsp, etc. and all you do i hook up the turn on, i think you're just out of luck with the pop.

the hiss is hard to tell exactly how loud it is on the video. but some amps have more than others. it just matters how much it bothers you. obviously more than you want.

just curious though, if you ever added rca shorting plugs when on the bench and if it changed at all? 

my guess, that's the way they are.


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## The Max (Aug 4, 2012)

Keep in mind that to do proper testing for hiss, you need to terminate your inputs. That is, connect some kind of load to them, even if it's an el-cheapo CD player or whatnot. Otherwise, noise is to be expected from unterminated inputs.

I can't explain the popping at turn on other than it's probably a crap design from Pioneer. I've never had an amp pop on me, though I've only ever used Sony (before the ****ty Xplod series), Rockford Fosgate and recently, Arc Audio. The key is to have amps switch on after all other audio devices switch on. In your case, you're just switching on the amp with no devices plugged in so there's no reason for any popping.

BUT, having said that, I'd still recommend plugging in some kind of line level source into the inputs and then trying the tests again. If it happens again, I'd axe them and save some dollars for more decent amps. That said, I'd stay away from the Rockford Fosgate amps. They've never impressed me and I got rid of mine recently.

I used to use Sony XM-754HX and XM-1002HX amps between '98 and '04. After that, the XM-754HX was sold due to being insufficient power for my tastes. Otherwise, it was the cleanest and sweetest sounding class A amp without blowing the bank balance, for a car. It was replaced with a Rockford Fosgate Punch 850.4, also class A. The problem with this amp though was that it had the typical alternator whine noise, which I fixed myself after modifying the board with a small network of capacitors. After that, it was fine. Still, for that kind of money, no manufacturer can excuse allowing noise into their amps from the power input and it was fundamental electronic design that shouldn't have gone ignored.

Anyway, moving on to my current vehicle, I have absolutely no room for a class A amp in my trunk, so it was my first foray into class D amps. I've heard them in commercial installations, I'm aware of them being used to feed subs but I was dubious about using them to feed quality full-range speakers, in a high pass setting as I normally do. I listened to a few of them and I decided to give Rockford Fosgate another chance with their Power T800-4AD 4 channel amp. No alternator whine, which was refreshing but the one thing I immediately noticed during the first of my music collection with quiet passages, just the sound of a subtle female vocal, violin or piano and I can hear a rough edge to the top end of the frequency spectrum, as though there's a DC offset or the noise floor adds to the actual music being played. Loud passages hide the anomaly but otherwise, very annoying.

So that's a case of Rockford having blown their second chance with me and that's why I don't recommend them. However, the Arc Audio XDi v2 series is fantastic. A little pricier but the ears know what they love and my ears tell me I definitely made the right choice from the moment I heard them in action in another vehicle. Best of all, they have an even smaller footprint than the Rockford Fosgate as well. That means more open space around the amp in the concealed mounting spot for more air circulation.

At any rate, whatever your budget is, double it and then take double the time to save for it. Because let's face it, you spent little in the short term but now you have to get rid of them to buy something actually decent and that means you've already lost money on what you're going to be selling off. Did you really save anything then? Not really, some of that money disappeared into thin air. 

Pay good, get good, get it once. What you don't save in the short term, you'll certainly save in the long term. At least, that's the principle I go by. Pity it didn't work for the last amp.


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## toylocost (Jul 4, 2011)

jtaudioacc said:


> with nothing else connected, head unit, dsp, etc. and all you do i hook up the turn on, i think you're just out of luck with the pop.
> 
> the hiss is hard to tell exactly how loud it is on the video. but some amps have more than others. it just matters how much it bothers you. obviously more than you want.
> 
> ...





The Max said:


> Keep in mind that to do proper testing for hiss, you need to terminate your inputs. That is, connect some kind of load to them, even if it's an el-cheapo CD player or whatnot. Otherwise, noise is to be expected from unterminated inputs.
> 
> I can't explain the popping at turn on other than it's probably a crap design from Pioneer. I've never had an amp pop on me, though I've only ever used Sony (before the ****ty Xplod series), Rockford Fosgate and recently, Arc Audio. The key is to have amps switch on after all other audio devices switch on. In your case, you're just switching on the amp with no devices plugged in so there's no reason for any popping.
> 
> ...


Thanks for the replies guys.

So to get some RCAs on it and redo the tests should I just grab a different head unit off my shelf and light it up too? Using what for input? A silent track, paused track, or something else?

And yeah I'd love to buy ARC or something like that but I am in college only working summers so it wouldn't be till next summer  I might be able to swing something a bit cheaper. I think perfect would be a pair of PDX V9s or some other 5-channels and I might be able to find a pair used if I wait long enough, but it's still a lot of money.


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## sirbOOm (Jan 24, 2013)

Will not need a track at all, just plug the head unit in via RCAs to the amp. You can also plug your phone in via the headphone out if you want.

Like I said earlier, I've never had any issues with these amps personally. I just put a 4-channel and sub amp in someone's car replacing water damaged old school MTX stuff and they worked perfectly fine. Maybe take them back one more time for repair? Can you throw one into a friends car, see what happens? Sometimes it's the car (ground issue, usually).


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## toylocost (Jul 4, 2011)

sirbOOm said:


> Will not need a track at all, just plug the head unit in via RCAs to the amp. You can also plug your phone in via the headphone out if you want.
> 
> Like I said earlier, I've never had any issues with these amps personally. I just put a 4-channel and sub amp in someone's car replacing water damaged old school MTX stuff and they worked perfectly fine. Maybe take them back one more time for repair? Can you throw one into a friends car, see what happens? Sometimes it's the car (ground issue, usually).


When I ordered these I actually ordered a 4th one at the same time, another 9601 monoblock for my friend's GS430 which I installed along with a couple JBL 12s. I checked his car after I heard my problem and his does the same thing he just cant hear it. Maybe I can hear mine better because of the infinite baffle instead of sealed box sealed inside a trunk?


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## The Max (Aug 4, 2012)

toylocost said:


> Maybe I can hear mine better because of the infinite baffle instead of sealed box sealed inside a trunk?


Hiss is hiss and doesn't have anything to do with enclosures.


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## toylocost (Jul 4, 2011)

The Max said:


> Hiss is hiss and doesn't have anything to do with enclosures.


Well yeah, it exists in both cases its just easier to hear with my setup. His is quieter because he has a box sealed in the trunk of a luxury car and I have a box pointed at the back of my head.


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## The Max (Aug 4, 2012)

toylocost said:


> His is quieter because he has a box sealed in the trunk of a luxury car and I have a box pointed at the back of my head.


Ah, I misunderstood you before. My bad.


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## toylocost (Jul 4, 2011)

toylocost said:


> So I called him this morning and he told me that when he first powered it up there was audible distortion with music. Which is not the problem I brought them in there for but when the woman at the counter is writing the work order and I can't explain anything to the tech idk why I expected that the message would make it's way to the tech clearly. Doesn't matter anyways since he probably wouldn't have done anything if he knew what I was talking about.
> 
> In the end he said he could barely hear it and that he didn't think it was a problem and that I could try a remote delay start. (My DSP has one built in that I was using) Then he sent me up front to talk with one of the installers, really cool asian dude wish I could remember his name. He didn't believe me that it would hiss even without RCAs connected and hooked it up on his bench so he could hear it too. He laughed at me when I told him to put his ear to the speaker saying "all amps do that!". Not sure I believe that all amps produce a hiss but I can't prove otherwise.
> 
> We talked for a while and he told me that I should try having the head unit turn the DSP on and then having the DSP turn a remote delay on which would turn the amps on. Still I am skeptical but have no other options at this point and I'm going to order a delay and give it a shot. As long as the hiss is not audible on volume level 1 and I can get the pop to a minimal level I should be able to live with it. Fingers crossed!


Well the delay came in the mail and I reinstalled it in place of the relay on my amp rack and put everything back in the car again... Now that I have midrange and tweeters in the car I can actually listen to music and hear these amps. Horrible. Gains were set with DD-1 and all three amps are at a decent amount less than half gain. 

Turn on and off pop is still there but with the delay it just takes 10 seconds for it to happen  not sure why I expected something else to happen. The guy in the shop seemed like he knew what he was talking about and I was hoping for the best. On quiet tracks the hiss is very audible, I can even hear it while driving. Turning my head unit to max volume on music is not very loud at all. I put a pair of Hybrid Imagines in my brother's Tacoma underneath the door panel on less power and it is MUCH louder. 

I'm considering driving the car to the shop and having them listen to it but even if they agree to walk outside and sit in it they will just tell me it's my install.


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## toylocost (Jul 4, 2011)

knever3 said:


> Press on Pioneer, you did the right thing by going to an authorized repair facility. They gave you the repair parts and labor list and nothing is fixed. It's time to push Pioneer or New Egg on taking back their product. I'm ashamed of New Egg, they should stand behind the sale for a period of time. And Pioneer telling you to service your new amp(s), terrible. These things are so cheap they are nearly throw-away so they should refund you money. I hope you get a fix soon, your build is very exciting!


Thanks for the compliment. 

I have called Pioneer again and all they offered to do was let me take it to another repair facility which is not in driving distance so I would have to pay shipping both ways and hope their tech agrees with me. I may call again but I don't think they will be much help.

New Egg has no obligation at this point because it was sold with a 1-year manufacturer warranty, I understand that. But more help would be nice even though it's not their fault, it would take a lot for me to want to buy from them again.


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## jtaudioacc (Apr 6, 2010)

anytime i try a new amp, dsp, etc. the one thing i'm always hoping for is really low noise floor.

there are a lot of products out there that just have a crappy noise floor. often doesn't bother too many people so they get away with it.

i've only done one of those amps recently and it was on mid bass drivers, so i never heard an issue. from what you've done, i bet i'd hear it if it was used for the mid/highs.


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## The Max (Aug 4, 2012)

Seems to me you're flogging a dead horse. If you can't get BBB to help you get a refund on the items, deal with what you have while you save for a decent amp to replace it with, then sell it off. Otherwise, this saga won't end for you. 

Sent from my SM-N910G using Tapatalk


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## GEM592 (Jun 19, 2015)

Do they even list a signal to noise spec for these amps? Geez


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## The Max (Aug 4, 2012)

Um, yes.

GM-D8604 Pioneer - Amplifier - Car Entertainment


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## CoLd_FuSiOn (Jun 25, 2012)

That's definitely a faulty amp I'd also advise that you sell it, they're nowhere near being Pioneer's good products. 

Sent from my One Plus One using Tapatalk


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