Speaker Hiss

[moosebump]

I just got a 2017 Z1 and seem to be having some electrical issues. The tower speakers hiss quite loudly even if I mute the stereo. The only way to get it to stop is to turn the Touch system off. When I turn it back on the hiss might stay off for a minute or two but then inevitably comes back. Also, the video screen stopped working but then later kicked in again.

I'm no mechanic or electrician so don't really know where to start. The dealer told me to take it to a stereo repair shop but that would mean a pretty long day of pulling the boat out of the water and driving back and forth a long way from the lake.

Anyone have any ideas of simple things to try first? changing fuses?

[chpthril]

The dealer told me to take it to a stereo repair shop

Was this their first and only attempt/advice or has anything been done in an attempt.

Normally, I would agree 100% with this advice. However, your selling tige dealer needs to take this up with Tige first. 1) its under warranty, 2) there are two major components that can result in speaker hiss and both are vendors to Tige. Tige will need to and likely already is, working with those vendors to resolve the issue.

[moosebump]

This is the first attempt. I am a long way from the dealer and they know i don't want to bring it in unless absolutely needed. They told me to get a quote on a repair and they would then see if Tige would cover the bill under warranty. But i don't really want to haul the boat to a stereo shop to get a quote and then bring it back to get it fixed assuming the expense will be covered. I want to use to boat!

I am hoping to just delay taking it for a fix until the end of the season or until I have more time. In the meantime i was hoping there might be some simple things to try to fix myself. While not a great option i would even disconnect the speakers until fall and then get it repaired.

[chpthril]

There is no simple fix and there is no reason to drag the boat to the dealer without them having a plan. So again, You need to have your dealer with tige for a resolution and tige will work with their vendors on said resolution.

Since your boat has zone control, just turn the tower zone volume down or just keep a little music playing to drown the hiss.

If your dealer does not want to offer help after the sale, then contact tige directly yourself.

[Langwell]

Soooooooo , this is an equipment issue or connection issue? I have a 17z3 with the dsp amps (i think) i have a local wet sounds dealer that can "adjust" the non adjustable amps. Just trying to see what others were doing and how it was resolved. Dealer and audio shop are about 30 minutes away. Just wanted pointed in the right direction , lol.

[Langwell]

What 2 components create the hiss ? What 2 vendors? Sorry for all the questions but want to be educated when i contact the dealer.

[chpthril]

Murphy media source unit and wet sounds amps and speakers. Either can be the source or contribute to the hiss or other issues.

[Langwell]

Your a fine tuned machine. Thanks again for all your help.

[IDBoating]

Obviously defer to ChpThril on marine audio issues, but a common cause of hiss is having too low a preamp output signal level and thus too much gain in your main amp. Less-experienced installers often don't consider the entire signal chain and just crank up the final's gain.

Not sure if this translates to this situation (does Murphy's media source unit serve as a preamp?) but wanted to toss it out there in case it helps.

[chpthril]

The hurdle with the 2017 and up systems is that the amps are DSP and therefor factory tuned with a reprogrammed tune. Nothing for an end user or boat dealer can do on their own. Resolution will come from Tige.

The Murphy is a preamp, just dont know how strong of one it is.

[hcooperrn]

I was told the preamp is actually high, around 5v, on these systems in one of the many conversations I've had with different people trying to find the cause of the problems.

That's just hearsay, I haven't measured it. I can't test or do anything at all though right now, as I have a permanent media connection error now.


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[duffymahoney]

All wetsounds rev10s hiss. I have been on probably 20+ boats with them. All have a slight hiss, so are worse then others. I spent so much time to fix it on mine and finally just gave up. I actually just put a switch on the helm to turn just the tower speaker amp off completely when not in use. That gets rid of the hiss.

[chpthril]

Before blaming a speaker, or anything else, you need to understand how/why the rev-10 gets blamed for noise. Unless there is a clear fault in a speaker, it will not produce any noise. What it will do, is reproduce any noise on the line, whether its AC or DC. This is what we hear as noise. So why does it seem as though the Rev-10 makes noise? Because 1, its a large speaker with larger tweeter (compression driver) and its like 10X more sensitive then a traditional coaxial. So the slightest bit of unwanted noise, is easily reproduced at an audible level.

Now, even in the best of tuned systems, you will have an audible white noise of you stand in front of the speaker with the music paused. This is even worst when streaming BT and pause from the phone. leaving the volume turned up.

Beyond that faint white noise, an audible hiss is usually related to improper gain levels, ie, tuning. whine with engine running and no noise with engine off, is usually related to an installation issue. However, we have seen some ground looping when a mix of amp brands is used, but we're getting real deep there. Static and pops can be poor signal connections, improper wiring, etc. There are some overlapping steps for these issues and there are different steps to isolate and eliminate.

So, lots to be done before anyone should toss in the towel and decide to live with noise.

[IDBoating]

Unless there is a clear fault in a speaker, it will not produce any noise.

x2! A speaker is a passive device. It only (attempts to) reproduce what appears on its terminals.

Actual hiss (white/pink noise) comes from active electronics: Some sort of amplifier, whether the output of a tuner/CD/other source, or a dedicated preamp, or an equalizer, or a final amp. If you don't believe this, disconnect the offending speaker, short its input terminals, and listen for noise. You'll hear nothing. Remove the short and you'll STILL hear nothing. But put the speaker wires on a scope and you'll see plenty!

If you're really wanting to dig into the details, you can reconnect the speaker and short the input to the amp. This guarantees the amp is seeing ZERO input signal. You'll almost undoubtedly hear hiss now, unless the amp is gated (which I don't expect on amps like this). The technical term for hiss is noise, and all amplifiers generate noise. They might play games to minimize your awareness of it, but all amplifiers generate noise.

Next, plug in whatever is in the signal path before the final amp and short ITS input. You'll hear noise again, perhaps more than before, because both amplifiers are generating noise. The first one generates some, and the second amplifies that PLUS adds more noise of its own.

The trick, as ChpThril pointed out, is to properly set the gain levels (I object to the use of the word "tune" in this context but everyone uses it, so let's say "tune"). Too much gain in any one stage can lead to excessive noise. This is particularly common in final amps, which don't usually worry much about noise level because they are large signal devices... preamps pay a lot of attention to noise because they are small signal devices. Many finals don't even bother to provide a noise spec. But if you crank up their gain to compensate for too-low gain setting(s) earlier in the signal path, that final will be delighted to amplify its noise for you!

Finally, it should be noted here that "modern" (read: digitally controlled) final amps will almost always be noisier than pure analog finals. Without going too deep in the weeds, the reason is because when you are setting the gain of a (properly designed) analog amp you really ARE setting its actual gain; reducing its gain ALSO reduces the amplification of its internally generated noise, and going to zero on the gain setting actually yields (near) zero output. In contrast, a (IMHO poorly designed) digitally controlled amp often runs its finals at a fixed gain level, and when you adjust its "gain" (whether at the amp itself or remotely via networked data) you're really just changing the level of input signal that is applied to the fixed-gain final stage. This means the noise is always amplified by the same amount no matter how strong or weak the input signal to the final amp is, which also means your signal to noise ratio varies with volume level. Turn the "gain" all the way down and you still hear noise (hiss) because all you've done is kill the input signal... you haven't actually reduced the gain of the amplifier and thus haven't reduced the amplification applied to the amp's internally generated noise. So, if you have "modern" digitally controlled amps, there may be a lower limit of hiss/noise that you will have to tolerate. It is definitely possible to design a digitally controlled amp to have true gain control, but I've seen a lot of examples where companies cheap-out and take the easy road and just cut the input signal while letting the finals run wide open all the time. I don't know if anyone makes a properly-designed digitally-controlled marine rated final amp... ChpThril, are you aware of any?

[moosebump]

I appreciate the education! Waiting to hear back from Tige after telling my dealer to contact them first.


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