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Old    Darrin (Cabledog)      Join Date: Dec 2013       08-13-2014, 3:14 PM Reply   
Hey guys, I was hoping someone could help me out with some stereo noise I am having in my tower speakers. I found tons of WW threads on the topic but most that I read were for alternator or engine noise. My problem is that I have a hiss from the tower speakers when the boat is on or off at zero volume. Here’s a few details

• Separate amps for sub, in boat, and tower
• WS420SQ
• All amps and EQ are grounded direct to the batteries.
• Boat has a stereo switch on the dash to supply power to the head unit. I did not change how the HU was hooked up from the factory and do not believe the ground is direct to the battery.
• Hiss increases with gain increase. Gain is at maybe 60%
• Tower speaker amp is an Exile XM30.2 driving 4- XM9
• Noise is only on the tower speakers

Thanks
Old    TigeMike (chpthril)      Join Date: Oct 2007       08-13-2014, 3:40 PM Reply   
Quote:
Boat has a stereo switch on the dash to supply power to the head unit
Most likely, that switch is actually only triggering the head-unit's red turn-on wire. Since the noise is what seems to be only gain-hiss, I would not suspect its an issue with the head-unit's B+

Quote:
Hiss increases with gain increase. Gain is at maybe 60%
That is expected

Quote:
Gain is at maybe 60%
High IMO, considering you have an EQ/Line driver like the WS-420SQ
Old    Darrin (Cabledog)      Join Date: Dec 2013       08-13-2014, 3:52 PM Reply   
Thanks Mike, so are you saying turn the gain down until it goes away? If so then how do I get the full power from my amp if that's the right way to word it? I can hammer them all day now without distortion and my bass keeps up so I don’t want to lose clean volume.
Old    David (DavidAnalog)      Join Date: Sep 2013       08-13-2014, 4:04 PM Reply   
Quote:
Originally Posted by Cabledog View Post
Hey guys, I was hoping someone could help me out with some stereo noise I am having in my tower speakers. I found tons of WW threads on the topic but most that I read were for alternator or engine noise. My problem is that I have a hiss from the tower speakers when the boat is on or off at zero volume. Here’s a few details

• Separate amps for sub, in boat, and tower
• WS420SQ
• All amps and EQ are grounded direct to the batteries.
• Boat has a stereo switch on the dash to supply power to the head unit. I did not change how the HU was hooked up from the factory and do not believe the ground is direct to the battery.
• Hiss increases with gain increase. Gain is at maybe 60%
• Tower speaker amp is an Exile XM30.2 driving 4- XM9
• Noise is only on the tower speakers

Thanks
A few things come to mind.
First, the horn tweeter in an HLCD is about 10 dB more sensitive than a conventional or standard tweeter so you will get the equivalent of ten times power in the noise level. That is why you hear it on the tower only. It's likely in the other zones but just not noticeable until you place your ear directly on an in-boat coaxial speaker. The subwoofer amplifier lowpass filter pretty much kills any hiss and woofers don't reproduce treble very well. Remember that anything that accentuates the treble will ruthlessly reproduce noise or hiss.
60% amplifier input gain sounds a little high when you have an EQ with a 5 volt line output and you are running stereo at a 2-ohm load.
Try this. Disconnect the RCA input to the amplifier. Any noise you hear under that circumstance is owned by the amplifier. Any decrease in noise level is a product of components or gain mismatches upstream in the audio chain.
If the main source of noise is upstream then you need to look into the source output to EQ input relationship and how you have managed the EQ gain, whether the front panel settings or the internal gain controls.
A low voltage source like an ipod, iphone, weak HU, or Sat radio tuner, can really compound the noise issue.
Your best shot at low noise is with high gain at the very beginning of the signal path and carried through at every stage of the signal path. One weak link causes the impetus to fall on the subsequent gain stage and any substantial gain increase in any one gain stage is a certain prescription for noise.
If you purchased your EQ from Odin at Earmark Marine then check in with him for a step by step tuning method. Besides his 25+ years in mobile electronics, Odin was a sound engineer in a club for ten years doing the sound set-up for hundreds of different touring bands. Plus, he's a musician. Odin understands gain structure/noise/dynamic range better than anyone I know.
Old    Darrin (Cabledog)      Join Date: Dec 2013       08-14-2014, 7:37 AM Reply   
Thanks David, I will try to isolate it this weekend.
Old    Diggs (pdxWAKE) (tyler97217)      Join Date: Aug 2004       08-14-2014, 8:01 AM Reply   
I always had a hiss with the WS420 when I used to use them also... No matter what we did it was there, but there were ways to reduce it. Seemed to help to turn down the volume on the MIC nob on the WS420 and it reduced it...
Old    Darrin (Cabledog)      Join Date: Dec 2013       08-14-2014, 11:40 AM Reply   
Good call on the mic knob Diggs. Thinking back the noise problem became more noticeable after we had some friends out with us and we were using the mic at a high volume to call out instructions and tips to the groms. Between that and the gain hopefully it will solve the problem. What EQ do you use now?

Last edited by Cabledog; 08-14-2014 at 11:42 AM. Reason: missed word
Old    Shane Rice (Shane10p)      Join Date: Jul 2013       08-14-2014, 12:08 PM Reply   
I had the exact same issue with the WS420 in my last boat when I added it. I didn't have any issues previously with the system and then added the 420 and had lots of noise in the system. Ended up taking it out and just doing sub and tower knobs to control volume. Sounds like this might have been a common problem my installer warned me about it previous to me putting it in... He was right.
Old    Diggs (pdxWAKE) (tyler97217)      Join Date: Aug 2004       08-14-2014, 12:15 PM Reply   
Darrin
I don't have horns with my current system and I am not using an eq any longer. I had that WS420 on a few previous boats with horns and that has always been a discussed topic since it came out. You should be able to reduce it for sure, but my guess is you will always have some his..
Old    Darrin (Cabledog)      Join Date: Dec 2013       08-14-2014, 1:00 PM Reply   
Bummed to hear it’s a common occurrence. I too had no noise before adding it but I feel like the 420SQ really helped my system come alive and provided complete control over the zones compared to my HU. The Exile ZLD wasn’t available as they were between models when I built my system but now that a new one is out I might buy one and try both if the other suggestions don’t work to eliminate the noise. Then just sell the one I like least. But I really like the dual EQ and mic that the 420SQ offers.
Old    David (DavidAnalog)      Join Date: Sep 2013       08-14-2014, 1:48 PM Reply   
Darrin,
Don't throw in the towel.
Every external signal processor and every additional gain stage will add some degree of thermal noise (hiss). No exceptions. The difference is whether the noise is audible and a distraction under normal operating conditions.
I have yet to see a professional installation that included the Wetsounds WS420SQ equalizer where the boat owner couldn't live with the noise, complained of the noise, or where I personally found it intolerable or even a distraction. Admittedly my exposure has been limited to dealers who knew what they were doing. Any number of competent mobile electronics and marine audio dealers will share the same opinion.
Oftentimes the relationship between the upstream source and EQ input is just as critical as the relationship between the EQ output and next downstream component.
Another point is that the newer WS420SQ is a different animal that the first generation product (which was a very long time ago). So comments based on the original aren't really accurate today.
Call Wetsounds or your Wetsounds dealer for quality assistance. Then take the steps they recommend.
Old    Russ Constable (Midnightv10)      Join Date: Feb 2012       08-14-2014, 1:49 PM Reply   
For what its worth:

In my old boat I had 3 Fosgate amps and a WS 420. Tuned by ear and had some hiss especially out of the towers (4 Pro 80's) at the time. Could not really ever get rid of the his other than to turn the gains way down.

Then when I got my current boat I installed 4 WS SYN amps, and the same 420 only this time I put an ARC Line driver between the head unit and the 420 and tuned the system with an SMD distortion detector. That system had NO NOISE whatsoever and my gains were set perfect (at least according to the DD that is.

This year I upgraded to 3 WS SD amps, and the 420SQ. Still use the line driver and again tuned with the SMD DD.. still NO NOISE whatsoever..

Honestly I really need to run a little test and bypass that line driver to see if it is really the ticket but just have not bothered since the system sounds so freaking good!
Old    Darrin (Cabledog)      Join Date: Dec 2013       08-14-2014, 2:45 PM Reply   
David, to your point the noise is only a distraction/ annoyance at zero volume so it’s not an all-day all the time thing, but I’m kind of OCD and know it’s not right. As long as I’ve got your attention as you seem to be an authority on WW for all things audio, when my sub really hits hard I can smell the electricity after a few minutes. I never noticed the smell in any of my car audio systems but the subs were always away from where I sit. In the boat it’s right under the helm. Is this normal or am I damaging anything? It only happens when I really get after it. I have an XM12.1 running a X12DVC.

Russ, I know just enough to do a clean install but not the inner workings of the equipment so I’m probably my own worst enemy. If I’m understanding this right the line driver after the HU pre EQ amplifies (and cleans?) the signal to the EQ then the EQ (WS420SQ in my case) has a line driver to amplify the signal downstream to the amps. This then provides a consistent signal level/ path from HU to amp therefore reducing noise? Sweet MB by the way.

My HU is a Clarion M303 and is direct to the 420SQ now.
Old    Russ Constable (Midnightv10)      Join Date: Feb 2012       08-14-2014, 3:03 PM Reply   
Darrin - yes that's basically the jist of it. As you mentioned the 420SQ has a line driver built into it. the lower signal voltage coming out of the head unit (M-109 in my case) gets boosted by the 420 before being sent to the amps. My theory (and David can probably put it into big fancy tonal quality type words) is that the line driver boosts the signal before it hits the 420 which then only "passes through" the EQ not requiring it to boost it any further and subsequently inducing further electrical noise to the signal.

another way to put it would be "Its Magic!"

Incidentally, my amp gains are all set at around 30% - 35% using the SMD Distortion Detector and my system is very clean and very loud!

I have never heard of being able to "smell" your subwoofer but I LIKE IT!!
Old    Darrin (Cabledog)      Join Date: Dec 2013       08-14-2014, 3:36 PM Reply   
Me either but I gotta admit I like it too. Even if it is wrecking it. Lets me know its working hard. Probably have the gain too high.... Bounces my phone an inch or so in the air off the dash when it hits, probably wrecking the gauges too with vibration but you only live once and its under warrenty.

Brian with Exile has offered to tune it for me but they are a couple hours from my area. Maybe in the off season I will take him up on it.
Old    Brian (brianinpdx)      Join Date: Aug 2009       08-14-2014, 5:00 PM Reply   
cabledog - turn your gains down 15% on all your amps. smelling the woofer is bad sign. Your overdriving it. Burning a voice coil isn't something covered in a warranty. When you smell it, your your to the point that your driving distortion thru the woofer at a level that is starting to cook the VC. At some point, you will loose the sub.

As for the hisssssss. Bring your gains down on the amplifier and see if you can eliminate and or reduce. If no real change, then by pass the 420 and listen again. Then advise for more input.

In 90% of the boats I listen to or that stop by and ask for tuning help I find the same situation regardless of the brand gear involved. OVER GAINED. Gain is not a volume control. And by pushing to much gain in the system, your asking for blown speakers to happen down the road. Not to mention the sound quality turns ugly and the hisssssss is in the system.

-Brian
Exile
Old    Darrin (Cabledog)      Join Date: Dec 2013       08-14-2014, 5:16 PM Reply   
Thanks Brian. I will follow your advice and circle back. Do I have the wrong sub paired with this amp if I'm smoking it? Big 12?
Old    David (DavidAnalog)      Join Date: Sep 2013       08-14-2014, 5:37 PM Reply   
Darrin,
Smelling the woofer voice coil, or any speaker for that matter, is really bad. You are doing damage. That smell is caused from over-heating the enamel coating that insulates the voice coil wires. Continue doing it and the enamel coating eventually is burnt away, including the former adhesives, until the coil windings begin to touch one another. At that point the woofer is toast.
Keep in mind that your amplifier has the potential to deliver twice the power the woofer can thermally dissipate and if driven into hard clipping any amplifier can produce a multiple of it's full power, but at a very distorted level. So a re-tuning is definitely in order. But you still need to be able to audibly identify what distortion sounds like if your equipment is going to last. Btw, stay off any bass boost or bass equalization.

As for the noise, if you don't have distracting noise on the in-boat coaxials then the noise isn't really an extreme condition. It's fixable. To explain just how sensitive a tower HLCD is in reproducing the noise, consider this analogy. Cut the tower amplifier gain in half (-3 dB) and listen to the reduction in noise. Cut it in half again. Cut it in half again (for the third time). You still have yet to reach a 10 dB offset. A horn tweeter that accentuates the highs also accentuates the background hiss. A typical tower HLCD horn tweeter is giving the hiss a 10 dB advantage.
Bypassing the EQ is simply bypassing another gain stage and there will automatically be a reduction in noise, but it does nothing to explain the actual cause and what steps are taken to reduce the noise while maintaining the EQ.
The input source to the HU can also be a factor in noise, especially when using a low gain source such as ipod, iphone, outboard Sat radio tuner, and particularly Bluetooth.
Note that one user has a WS EQ with "NO Noise". That or very low noise is the more common outcome for systems professionally installed and tuned. Correct set-up and tuning is likely to be your remedy.

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