random volume fluctuations alpine

I just installed an Alpine UT52BT headunit, with the KTU445U mini amplified, Type R components, and the RUE-MR1F remote in my motorcycle and I'm having a VERY odd issue. The volume is randomly adjusting itself (can see the volume change on the display). It doesn't seem to be linked to anything that I can find, and it is completely random (could work great for 30 min of riding then randomly just shoot way up, drop way down, or bounce in between).

Any ideas?

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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205

By the heading I was thinking grounds...
But the display means it is changing.
It could be noise that is getting thru and 'signalling' the CPU, tho I'd expect Alpine to have damned fine power etc filtering, but bikes can have pretty harsh electrics and interference. Can you test it in some other vehicle? Else add some supply filter; then maybe moving or adding radiation shielding; and ultimately speaker filtering or shielding...?

Of course it could be a faulty unit - quite possibly a bad connection or dry joint etc (esp between the digital (pulse) dial and the main circuitry).
And maybe bike vibrations effect that. (Try hitting hit or a vibration test.)


BTW - I assume it does not automatically adjust volume depending on 'ambient' noise?

I'm actually starting to wonder if it's a lot simpler than I was thinking. The radio has a volume dial... I'm wondering if maybe the vibrations of the bike are causing the dial to make connection which would explain the randomness. I may try to stuff a piece of paper or something behind the dial to hold it in place and see if it goes away. I check all of the wiring (power, ground, etc). I also made sure to move the antenna for the remote away from anything that I thought could provide interference (amplifier, powered antenna, radio, etc).

It is not linked to noise (volume goes up and down with the same / similar ambient noise), nor do I have the bluetooth mic connected (since those mics can barely filter out noise in a car... not even going to attempt it on a bike... lol).


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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205

Yeah... I assumed it is a typical modern 'digital' volume dial. They typically have 2 sensors that detect (overlapping) slots but it can be anything from wipers & copper tracks (tho not these days!) to optical sensors & choppers.

Vibration could cause disc movement. Whether the triggering of only one sensor can make a (volume) change depends on the (logic) design, and whether vibration can effect BOTH sensors depends on the mechanical design.

An intermittent connection can also simulate sensor detection...

If still under warranty I'd be tempted to try a return & borrow to see if another unit behaves the same. If it does, then (that?) Alpine isn't suited your MC environs. (It's not one of those nasty 45-degree V-twins is it? And HT cables are well away?)

I wonder if the easiest initial test would be a cap across the power feeds - probably a small 0.1u or 0.01uF greencap etc, but maybe (later?) a larger electrolytic if not both.

Or maybe try another faceplate.
Oh - clean the faceplate contacts first - just in case they are contaminated. Check too that all contacts look ok.


I think dial inspection and repair will be difficult. I've had 2 of mine apart - the first to find what had blown after my >16V alternator issues (bad engine to chassis ground!) & the second to try to add display dimming. In both cases I found inspection quite difficult - not that I was looking for suspect connections as you might - but as I recall, track tracing etc was difficult.
And since digi-pots are usually sealed and many circuits are integrated blobs, one is limited to the luck of finding an external suspect component or track. Even the latter has become becomes nigh impossible with multi-layer PCBs and internal vias etc.

Still, I'd suspect a faulty Alpine. Firstly because they are quality units, and secondly because tho I haven't had one on a bike, my driving is such that contents suffer shocking g-forces, and fast corrugations are not uncommon. It wasn't unusual to have CDs miss or skip. LOL - I've even had my mp3 stick miss.... maybe the inertia of electrons under the effect of the momentum of gravity is just too great for my driving habits?

Well I popped off the front of the fairing over the weekend and completely redid all of the wiring. It was a bit of a mess because my original planned layout didn't allow the fairing to go back together properly so I had to move things around... which ended up making a bit of a mess with the wiring. I also moved the amplified antenna and the amp away from the wireless remote antenna. So far it seems to be fixed. I went on a few long rides and haven't had the issue. But I do have to pull it back apart again because I think a wire came off of one of the plastic holders because out of nowhere my right side speaker started sounding like it was blown... but then cleared up after a minute or so. Thanks for the help!

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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205

Interesting... If bad connections, cool - but I wonder if it could have been noise/interference from antennas etc? No big deal; merely curiosity. Problem fixed.

As to bike wiring and fairings...
Didn't Black Sabbath write a song about that... "Fairings Bluddy Fairings"?
(People wonder why I want a naked bike!)


PS - apologies for saying "Problem fixed". I know that means it won't be...

I loved the bike naked but hated now having tunes. I was pleasantly surprised by the clean fit and how the bike maintained the 'sleek' look of the bike. And now I can listen to my tunes while cruising... without having to deal with painful and dangerous head phones inside my helmet.

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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205

Ok, so I've got a new one now (this thing is proving to be a major PITA). Every once in a while the right side speaker will sound blown (that horrible distortion sound with any kind of bass, crackling, etc). But after a few minutes it goes away and sounds perfectly fine. The amp is bridged, giving the speakers 45w RMS which should be fine. And the radio is not up all that much (maybe 1/2 way).

I'm going to check and make sure the wire hasn't found it's way inside the basket, but I don't think that's it. I'll also check the gains on the amp, but they should be good. I just don't get how it can do it and then go away a couple minutes later...

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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205

Why would you bridge your amp? Ever hear of STEREO SEPARATION? You now have a MONO system.

The amp is designed to be bridged. The stereo separation is still very much present and noticeable; so I'm not entirely sure what you are getting at...

https://support.alpine-usa.com/products/documents/OM_KTP-445U.pdf

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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205

The KTP-445U is a 4-channel power booster that can be used as 2-channel. It's not exactly the highest quality sounding unit, but in a restricted space install it can be useful. It distorts horribly if pushed, by the way.

Back to the original question, what kind of motorcycle? Many bikes do not have a very stable 12V system, and in fact often fluctuate from 8V up to 20V depending on the engine RPM. This can play havoc with audio electronics. Also, the extreme vibrations in some bikes like older Harleys can cause electronics to fail and to do all sorts of strange things.

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Support the12volt.com

It's a Yamaha Star Stryker. I am pretty sure I've got it all figured out. I took it all apart and checked the wiring. With everything being so tight back there and no where to really tie the wires up, it looks as if the speaker wire was getting between the speaker and the basket. I fixed it, adjusted the gains on the amp up slightly (to help prevent distortion by having to turn the radio up). So it sounds absolutely amazing now at only 1/2 volume on the radio and so far no further issues. Thank you guys for the help.


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Kenny
Owner / Technician
KKD Garage LLC
Albany, NY 12205