Constant Speaker Hiss troubleshooting/ advice??

[Paxdad]

I have aconstant “hiss” sound through my speakers when the volume is turned down fairlylow to no volume at all. With the volume turned up the “hiss” goes undetectedthat I can tell. Please note this is a “hiss”not a “whine” that is commonly producedfrom an alternator noise. The hiss is constant and does not get louder with anincrease in engine RPM etc or increase in volume. The hiss is there when theengine is off and system on as well.
Here is abit of information that I hope helps:
Boat: 2008 SANTE210

• Clarion CMD 5 head unit with remote (I do notuse the head unit other than to power on the system) Remote is set to AUX.
  
• WS 420 EQ- It is the model before the presentmodel out now
  
• Arc Audio XDi805 amp for in boat speakers and WS10 subwoofer
  
• Arc Audio 600.2 amp for WS Pro 485 towerspeakers

As far as I can track down the ground for the 600.2 isrunning directly to the port battery post and the ground for the XDi805 isrunning to the existing ground wire that is in the stock wiring harness for thefactory (old) Polk amp. I assume it is running to the battery selector switch.I have not been able to determine where the ground for the head unit is runningto specifically however, it appears to be tied into some other ground wiresrunning to ???.
12v positive power to both amps is being supplied by one ofthe original wires from the circuit breaker and the other positive wire isgoing to the positive battery selector switch on the starboard side of the boat. Any assistance in how to proceed fromhere to eliminate the hiss will be greatly appreciated. I had a local marinestereo service due the amp upgrades last year and have been really disappointedin the install details to say the least, and don’t care to take it back norrecommend them to others in my area.

[core-rider]

Number 1 thing to do is make sure ALL stereo components are powered from the same source... HU, EQ, amps... everything! It sounds like your grounds are coming from different sources which most likely is the problem. It creats different resistance values for each component and that is transfered to the speakers in the form of noise.

Move all the gounds to a common source B- and see if that doesn't help.

[Paxdad]

Core,
I agree with you on the ground being the likely cause. Just so I understand are you saying to start by running all the grounds to the same B- on the one battery where the 600.2 amp is grounded and leaving the B+ power sources as is for now? Or do both B+ and B- need to originate from the same source/ battery?

[ffmedic74]

Just to jump in, where is the best place to ground if you have a perko dual battery switch.

Sent from my ASUS Transformer Pad TF700T using Tapatalk

[core-rider]

Core,
I agree with you on the ground being the likely cause. Just so I understand are you saying to start by running all the grounds to the same B- on the one battery where the 600.2 amp is grounded and leaving the B+ power sources as is for now? Or do both B+ and B- need to originate from the same source/ battery?

Personally I would do both B+ and B- incase you ever ran into a situation where you needed to kill power to all stereo equipment. I guess for testing purposes you could temporary just the B- to see if it fixes your issue though.

[core-rider]

Just to jump in, where is the best place to ground if you have a perko dual battery switch.

Sent from my ASUS Transformer Pad TF700T using Tapatalk

Negative battery post is the best place if you are talking stereo equipment. You don't have to take all wires to the battery. I run a 1/0 gauge cable from the B- to a distribution block that splits to each amp and a small distribution block that handles lighting, HU, and EQ. In effect this makes all wiring go back to B-.

[David Analog]

It is possible that a difference in either the supply or ground potential could add noise, although rarely this type of noise as described. But you have to deal with and eliminate this possible cause first. ALL audio equipment grounds should reference the same point. ALL audio equipment positive supplies should reference the same point. This should be taken in the strictest sense. No exceptions.

Usually a constant hiss, like white noise, or like the sound of a distant waterfall, is a product of extra signal processing like an EQ or an inequity in gain between audio electronics.
Every signal processor will add hiss as a byproduct to some degree. Some more than others. It's a matter of how much you can reduce it and whether you can still tolerate it.
A tower HLCD speaker doesn't create hiss but will ruthlessly reproduce hiss just like it does music content. And for an HLCD to be effective and intelligible at wake range it must be voiced a bit aggressive in the treble region, where you are most sensitive, and where hiss is most audible.
You'll never completely eliminate hiss when the volume is all the way down and you are at rest. You can only minimize it. The hiss shouldn't be a distraction when underway and with the volume raised as both the wind & engine noise plus music content will mask the hiss.
So if you complete the first phase and you still have hiss you can move on and assume it's an equipment or gain issue. It can either be an inherent quality in equipment or an inequity in the gain structure between equipment. To narrow the cause of noise, disconnect the RCA input of the last electronics component (amplifier). Ideally you would short the RCA input rather than leave it open. Turn the input gain of that component to no higher than 35%. The noise remaining is owned by that component. Reconnect and move backwards through the signal path to the next upstream component (EQ). Disconnect it's input, reduce the input gain to a reasonably low level and repeat the test. Next, move to the source unit and test differences between various sources whether iphone or CD. For example, a low voltage iphone source or a Bluetooth module can reduce gain placing an inordinate responsibility on a following gain stage to elevate the gain....thus a multiplication of the noise floor. An introduction of an upstream component resulting in a sudden and substantial increase in noise will narrow your focus. Some causes are more fixable than others.
Also, keep in mind that amplifier and equipment input gain controls are by no means a volume control and a reduction in the input gain does not necessarily constitute a reduction in the final output power. With some consistency people tend to set gains too high, especially amplifier gains, and this directly creates noise. Ideally you want to begin the signal path with high gain/voltage and keep the gain level consistent from beginning to end. Or, begin with a high gain/voltage and slighty reduce gain from beginning to end. Never so much gain as to saturate an input of the following component, which is unlikely. And never having to correct a gain loss by significant multiplication in one stage/component. A gain roller coaster is a certain path to noise.

[core-rider]

This will better visualize what I'm saying. You can see the main dist. block on the left that runs to each amp and then another power dist. block on the right that handles the HU, EQ, and lighting power. A 1/0 gauge cable runs from the left dist block straight to the battery.

[David Analog]

Jason,
That's nice and clean. From a practical standpoint, I have always preferred evertything out on the surface. Easily to avoid a cluster behind the amp rack. Everything is strain relieved. Easy to diagnose. Easy to service.

[nyryan2001]

Not a grounding problem.

Funny with everything thats been written...none have said the obvious..... the WS420 is well known for speaker hiss. the WS420's pre amp volts arent all that impressive and cause folks to gain up their amps to compensate for lacking volume and introduce the hiss as described above.

cliff notes version to reduce as much as possible for regular folks:

1. ensure your gains on the top of the WS420 are all the way up max.

2. tune your system: amp gains at 1, HU at 75% volume, playing balanced music, one zone at a time, slowly bring gains on your amp up till it reaches a max volume you like, well before they start to distort. Clean undistorted loud music. Do your towers and inboats like this. Also ensure your crossover freqs are good for sub, inboats and towers.

3. Leave the amps. Go over to the HU and bring the volume to 0. how bad is the hiss?

4. Hiss still bad? back your amp gains down a hair at a time till you can accept the level of hiss. Crank the HU back up to 75% and detmine your new max. Acceptable?

You are generally have to choose a trade off between acceptable hiss and your max volume output. really how often do you need to blast at that max? Can you live with a little less?

Else, ditch the WS420 for the newer WS420sq or the ZLD. Pre amp volts are better, and allow you to run lower gains on your amps, much less hiss.

I did a direct back to back swap 2yrs ago from that same WS420 to a ZLD for this very reason... and hiss reduced big time. But that was back when all the audio experts were on the forums overcomplicaintg everything and convincing everyone it wasnt the 420, but that folks were clueless in what they were doing.

Right now I am consiering the move back to a 420sq, for the ability to adjust and tune the 3 zones truly independently. Curent/old ZLD applies 1 tune to both towers and inboats = bad. Waiting to see what this new ZLD has on it, which is about to hit market here shortly.

[core-rider]

Jason,
That's nice and clean. From a practical standpoint, I have always preferred evertything out on the surface. Easily to avoid a cluster behind the amp rack. Everything is strain relieved. Easy to diagnose. Easy to service.

Thanks David... I built it liike that for every reason you stated. It may not be as "clean" as hiding it all, but once it's closed inside a compartment you can't see it anyway.

[core-rider]

Not a grounding problem.

Funny with everything thats been written...none have said the obvious..... the WS420 is well known for speaker hiss. the WS420's pre amp volts arent all that impressive and cause folks to gain up their amps to compensate for lacking volume and introduce the hiss as described above.

I didn't look past the fact the OP stated his power and grounds were not from the same source. Most likely that will solve most of his problem. Your theory is posible as well, but could be all for nothing if power/ground wiring aren't sourced properly.

[nyryan2001]

^^ I'd 100% agree with you if the hiss increased or was related to engine noise, with the engine running vs less when off etc etc.

and I also 100% agree with you they should be all +/- to the same location. No doubt. But the fact that there is no increased engine noise when it is running, doesnt prove, but does suggest, that it is not a ground loop issue. Would be a dead give away if there were engine noise.

Its just that his symptoms exactly replicate what hundreds of other folks have went thru with the first version WS420 like he has.

hopefully he checks the gains on the top of the 420, and its gained down some....causing him to gain up his amps to compensate. Super easy fix and immediate relief from the hiss.

Im kinda hot on this issue... I chased the hiss across 2 boats... and it wasnt anything with how I had it wired, but by the design and performance of that first version 420.

[Chexi]

Bypass the WS420 and see what you get. I am betting no hiss. I have the exact same problems on my REV8s, and I am almost certain it is the WS420 and will be testing it out shortly.

[David Analog]

Everyone knows that the older Wetsounds EQ had a real noise issue and that the newer SQ model is an improvement. That's not news. However, results on the older EQ varied from installation to installation. No one was completely free of noise with the older EQ but some made the noise tolerable while others never could get it close. Pro shops often managed while consumers often did not. And that was the frustration that pro shops dealt with because they generally did not have the same experience with their inside projects. When finished and tuned correctly was there some hiss when the volume was turned all the way down and you stood up directly in the path of the HLCDs in close proximity? Certainly. But it was acceptable unless you had a source unit with anemic preout voltage. Iphones and Bluetooth modules don't improve things. I provided a prescription for determining exactly where the hiss culprit is. Improvement will come from more than a single remedy based on the mix of gear in a given system. The noise is not from a lack of EQ preout voltage as the unit had six discrete outputs that would deliver a solid 5 volts X 6 under every circumstance. That's more than adequate and more than a majority of EQs that split their voltage via a fader. Btw, the second running edition of the WS420 did not have input adjustments as they were removed which goes back many, many years.