Interference/distortion please help

[RawbDidIt]

Alright, I have a weird problem I'll post here, any help would be appreciated as I have NO clue what's going on. At high levels (30-40 out of 50 from the head unit) I hear distortion coming from my right rear speaker. At higher levels (40-45/50 from HU) it spreads to the front right speaker as well. Does anybody know what might cause this? I've been running this setup for the past 6-9 months with no changes, and it just started happening today. I've done some minor troubleshooting, the results of which are posted below, as well as components in the system.

Troubleshooting:

I put the balance and fade to right rear, and increased volume until I heard the distortion, then switched the cable so that same cable was powering the left rear speaker. Switched the balance to left and heard no distortion, so it's not my RCA cable running from my HU to the amp. The distortion at first is localized only to the right rear, but even with the balance and fade set to right rear, at higher levels, the distortion can be heard coming from the right front speaker as well. No other sound, just the distortion (sounds like the cone delaminated). Pulled the grilles off of both speakers, no signs of damage to cones or surround, no burnt smell either, same for amp. The only thing that I can think of is interference between speaker level wires leaving the amp, or the amp itself is causing the interference. I'm leaning towards the amp since the speakers seem physically OK, and I've been running this for months and have just now heard the interference.

Disclaimers:

The speakers are NOT overpowered. They are rated at 250W RMS, 500W peak, my amp is at about 2/3 max gain, and can only produce 85W/channel at 4 ohm load. My amp can't exeed the speakers ratings, and my HU can't push too much power to the amp as my gain is set well below max setting.

The amp is getting plenty of power. Beyond the fact that it's happening while only powering one channel, I also had the subs turned off, and I've installed a high output alternator as well. Volts never dropped below 14V for the duration of the troubleshooting.

My head unit has never had issues of distortion at these levels before, only at around 45 will it start distorting, and even then, it's audio clipping, not the sound of a physically damaged speaker.

System components:

Sony GS610BT HU

Avionixx CXA 1040 amp (4x85W @ 4 Ohm)

Brand X XL-692CX 6x9" speakers. (250W/500W)

I don't think it has anything to do with this, but I also have:

Avionixx 1220 amp

Realm by Scosche LFT10-D2 10" subs

Mechman HO alternator (120A @ idle)

70A fuse to PDU

40A fuse to each amp

Click to read more...

 

[loudenuff]

Alright, I have a weird problem I'll post here, any help would be appreciated as I have NO clue what's going on. At high levels (30-40 out of 50 from the head unit) I hear distortion coming from my right rear speaker. At higher levels (40-45/50 from HU) it spreads to the front right speaker as well. Does anybody know what might cause this? I've been running this setup for the past 6-9 months with no changes, and it just started happening today. I've done some minor troubleshooting, the results of which are posted below, as well as components in the system.
Troubleshooting:

I put the balance and fade to right rear, and increased volume until I heard the distortion, then switched the cable so that same cable was powering the left rear speaker. Switched the balance to left and heard no distortion, so it's not my RCA cable running from my HU to the amp. The distortion at first is localized only to the right rear, but even with the balance and fade set to right rear, at higher levels, the distortion can be heard coming from the right front speaker as well. No other sound, just the distortion (sounds like the cone delaminated). Pulled the grilles off of both speakers, no signs of damage to cones or surround, no burnt smell either, same for amp. The only thing that I can think of is interference between speaker level wires leaving the amp, or the amp itself is causing the interference. I'm leaning towards the amp since the speakers seem physically OK, and I've been running this for months and have just now heard the interference.

Disclaimers:

The speakers are NOT overpowered. They are rated at 250W RMS, 500W peak, my amp is at about 2/3 max gain, and can only produce 85W/channel at 4 ohm load. My amp can't exeed the speakers ratings, and my HU can't push too much power to the amp as my gain is set well below max setting.

The amp is getting plenty of power. Beyond the fact that it's happening while only powering one channel, I also had the subs turned off, and I've installed a high output alternator as well. Volts never dropped below 14V for the duration of the troubleshooting.

My head unit has never had issues of distortion at these levels before, only at around 45 will it start distorting, and even then, it's audio clipping, not the sound of a physically damaged speaker.

System components:

Sony GS610BT HU

Avionixx CXA 1040 amp (4x85W @ 4 Ohm)

Brand X XL-692CX 6x9" speakers. (250W/500W)

I don't think it has anything to do with this, but I also have:

Avionixx 1220 amp

Realm by Scosche LFT10-D2 10" subs

Mechman HO alternator (120A @ idle)

70A fuse to PDU

40A fuse to each amp

Hate to be that guy but I guess I'll do the honors. For one I don't think mechman makes such a small alternator. If you paid more than $30 more than you'd pay for an oem alternator then you wasted your money on that. Two, scosche subs aren't worth half the hourly wage of the peopple who make them. Bad driver, they wouldn't sound too hot to begin with. Two of that amp even did it's rated power it would blow those subs bc the power handling wouldn't be much more than 500 I believe. You NEVER turn an amp past 1/2 of the gain. Ever.

Thirdly, that head unit is low end. Which wouldn't be bad considering it's a budget build, if you had your gains set with an oscilloscope. But it's likely you didn't and tuned by ear, pushing the subs to get them as loud as you want them to be, which isn't good for the fact that it's a poor quality system.

Fourthly, that amp is low end and probably doesn't do close to rated without clipping.

You should really have done more research on this and not just assumed before purchasing your equipment. Would've ended up with a better system that might actually please you. Take this like a spoon of nasty medicine and don't argue it... you'll get a lot of hate making ignorant posts like this. Not trying to be an a$$ but nobody gave me info like this straight up and that's why I blew two grand on bad systems.

And audio clipping you can't hear. You can but not when it first starts. Any audio clipping will damage your speaker, you might not notice it immediately but your coils will seize before ya know it. Good luck.

 

[loudenuff]

Brand X is equivalent to scosche. By the way

 

[trumpet 5,000+ posts]

You NEVER turn an amp past 1/2 of the gain. Ever.

No, this depends on the input signal voltage, and sometimes the amplifier might have a range selector switch which also affects the gain knob position.

Thirdly, that head unit is low end.

Sony GS is good. The opportunity was presented to sell Sony while I worked at a shop, but there wasn't a need for another head unit brand. Sony is currently a very solid option for some of the top specialty retailers in the country.

And audio clipping you can't hear. You can but not when it first starts. Any audio clipping will damage your speaker, you might not notice it immediately but your coils will seize before ya know it.

You're partially correct. Some clipping may not be audible, especially if we're talking about subwoofers. Clipping is not an automatic death sentence for speakers. That is a myth. It goes back to real power handling and the amount of time of the power exposure.

 

[RawbDidIt]

That was a bit harsh, and was not at all helpful. The sound is coming from the door speaker, not the subs. I'm not under the impression that my system is the hottest on the block, nor did I ever brag about it like it was. You may not have meant to sound like an "a$$" but you sure accomplished it by tearing down the quality of my system in every area that isn't relevant in this equation. As for the Mechman alternator, you are correct, they don't offer an alternator that fits my model, but they were able to make a custom one for me, if you're referring to the level of Amps I listed, that's the idle rating at my engines idle RPM, not the max output, which I listed because during troubleshooting I wasn't driving around with my engine at 2400 RPM (because how/why would I?). I have no problem with constructive criticism, but your comments were not constructive in the slightest. I don't even think you looked up the part number I gave for the subs, as they are not 500W peak as you mentioned earlier, but 800W (400W RMS since peak doesn't mean squat). If you think the door speaker is bad, just say that and I'll send it back for warranty replacement, but since the sound is coming from other speakers (and only when the right rear speaker is powered, not when it's unplugged from the amp) then I highly doubt it's the speaker. So, if you're quite done ripping on me for not spending as much on my system as you spent on yours, can we please get back to the topic of what the heck is causing the issue?

 

[RawbDidIt]

Well, I found the problem. Turns out the rear speaker tweeter post had vibrated loose. Pulled the back plate off, pulled the screw and reinstalled with some locktite. It's been working for a few months now, so the sound must have been coming from the tweeter post vibrating.