Audio equipment question

[QC]

I have an issue with my boat's sound system. No need to discuss the merits of music on a boat, but for the record we are in love with having a big "system". Didn't know before we got it as it was already on our current boat. 1000 watts, 2 - 10" subs, 2 - 6x9s 6 - 6" mids and 4 - mini tweeter things, crossovers, professionally installed. Sounds as good as headphones

Anyway . . . I was losing sound from two speakers on the left side, but had others on the left channel still working. Jacked around with it yesterday and noticed that they would come back if I cranked it up, and they would continue working at lower volumes then. By this time I had wiggled and unplugged/replugged stuff, but I still think there is some validity to the increase in power and then a temporary "fix". The reason that I think there is some relationship is that my home stereo sometimes does the same thing. If I turn the home unit on and only have one side (hasn't happened in a while), if I crank it up it's like it "primed" the connection and then maintains it. Also no need to comment on my electrical knowledge, I know I am as dumb as a stump when it comes to Ohms, watts, James Watt, Amps, Volts, CCAs, AC/DC, AC/DC the band, AC/DC people etc.

 

[valkyr]

Re: Audio equipment question

Wierd...When you push the volume up, your increase voltage across your speaker wires. More voltage = heat in the wires. I guess you could have water in the wires that gets displaced by the extra heat. That might also explain the initial resistance. Moisture around your connections would increase resistance...

Don't know otherwise

 

[dchris]

Re: Audio equipment question

You either have a weak speaker wire connection or your amp is getting ready to go out. The electroncs would be sensitive to heating from playing it loud.

 

[nothreat]

Re: Audio equipment question

Don't know if this will help but I have a similar problem on my home stereo (don't know why, I bought it in 1982). I have found the if I squirt some electronic cleaning solution into the volume potentiometer (the part that the volume knob goes into) I can use if several weeks before it starts failing again. And it only fails again if I go a couple weeks without using it. I think it is dirt or corrosion inside the pot and the fluid and exercise completes the connection. I suspect your boat radio doesn't get that much use and it is in a moist, dirty enviroment (from electronic's perspective anyway). Hope this helps.

 

[QC]

Re: Audio equipment question

No pots on this unit, but thanks. I am worried about the tuner/amp cd combo deal, but that is the least expensive part of this thing and I almost yanked it just outta frustration. It has been cranked often . . . It's just way too much fun at the right time

 

[dchris]

Re: Audio equipment question

If you really believe it is a thermal problem, you can get a can of feeze spray and hit connections and the heat sinks on your amp. The other odd thing about ths problem is heat is usually the ememy and makes things worse.

 

[beerfilter]

Re: Audio equipment question

Without knowing exactly HOW the setup is wired,how many amplifiers,what speakers go to which amplifier , I'll say you MAY have a passive crossover going bad .
Just a guess,as there are a number of ways to wire that setup,depending on a lot of variables.
A single speaker acting up is most likely just that speaker or wire .
As the other speakers on that channel are fine ,I would rule out the source unit .

A few more specifics would be very helpful.

 

[SS MAYFLOAT]

Re: Audio equipment question

Either a capacitor that is having trouble energizing at low power or a cold soldered joint. You have a resistance build up somewhere. Once the voltage is high enough to overcome the weak spot (resistance) it goes away,,,,,,,,,,for now. Eventually it will get worse. In audio, I was taught that the lower the impedence is it is closer to a dead short.

Beerfilter may have a good clue to where it maybe at. Sometimes an overloaded crossover will damage the capacitors causing the so called resistance.

To find the problem, try switching the left and right channel input leads to the amp. If the problem moves, it will be between the input and your amp. If nothing, then switch the speaker channels to see if the problem moves to the other side. If it does, the problem could be in the amp itself. If it doesn't change, then the problem will be within that circuit for those speakers. The load coil in a speaker can also cause this problem. Unhooking the speakers one at a time on that line may help locate the gremlin.

Been a long time since I worked on audio equipment,,,,,,like back in the day of vacuum tubes.

 

[freddyray21]

Re: Audio equipment question

I had the same problem with the car stereo. Most likely dirty inside. As cheap as they are put a new one in. Not work fixing the old ones anymore.

 

[briannh1234]

Re: Audio equipment question

You probably have a bad connections somewhere. I would soldier all the speaker connections at the speakers, then backtrack from there soldiering everything.

 

[Limited-Time]

Re: Audio equipment question

beerfilter and SS seem to be on the right track there GC. Q? does the sound "go out" at low volume or is it not coming on at all on initial power up?? Another question,(taking in to account your admitted technical weakness in all things audio) do you know if the system is set up with multi-amps (bi-amplification) or is one big amp powering all the speakers??

 

[QC]

Re: Audio equipment question

Well I messed with it some today, but ran out of time. The crossovers are between the 5.25 and micro-tweeter deals. I pulled one today, but didn't have time to hook up the 5.25 by itself to see if there was any difference. Was acting up on both sides though today . . . Same sets of speakers, but opposite side.

On the power up thing, kinda both ways, I have had it on and then it started to act up later, but lately, Power up, nada, crank some and it comes back. When I was listening today right channel was fine and then it started to crack and crunch a little, snapped back to good, I cranked it, all good for a minute then it started crapping out again. Based on that I am thinking no on the Crossovers (switching sides)

Single 1000 watt amp, drives everything. At this point I have not eliminated anything really, messing with wires seems to help, but that could still be coincidental and wishful thinking. Isolated to front channel which I can still control with the "head" so the Power amp must be 4 channel plus the subs? Funny thing is I have a spare Amp, I think an 800 watt and different make, but I could use it for troubleshooting. The Tuner/CD/preAmp deal has a removable face and it is getting flaky too. Doesn't always make a clean connection and I have to mess around to get it on sometimes, but I chock that up to bouncing hard and flaky connections face to base. I guess it could be that too, as it is of course four channel . . .

I leave for Lake Powell tomorrow . . . So I'll probably play with it some there, but won't be posting until I get back on the 14th or so. I'm printing this and taking with. Thanks.

 

[Limited-Time]

Re: Audio equipment question

If you really want to kick the system in the azz, add the 800 watt amp to drive the mids and high range speakers and dedicate the 1000 watter to the subs. This could also tell you where the problem lies.

 

[QC]

Re: Audio equipment question

Thanks LT . . . You reminded me and I just thru it in the truck it's actually a 1000 watt Sony Xplod, so who knows what I may end up with.

 

[SS MAYFLOAT]

Re: Audio equipment question

Thanks LT . . . You reminded me and I just thru it in the truck it's actually a 1000 watt Sony Xplod, so who knows what I may end up with.

HEARING LOSS! Like Me!.....

 

[QuadManiac]

Re: Audio equipment question

QC, if the audio interconnects between the head and the amp are RCA connectors (center pin protruding with a shorter, concentric, notched cylinder surrounding it) simply try unseating and reseating them all (both at the head and at the amp) several times and twisting them a few times after re-insertion. There may be some corrosion build up on the mating surfaces that higher voltage is able to 'break through' in microscopic areas... just to return through corrosion growth after being idle again. If you can get to them, twist while the system is on, and see if you can hear the signal 'scratching' or coming and going. Often, RCA connectorized cables fail intermittently at the strain relief and moving them around will make and break the failed connection.

If that fails, remove and hit with some fine grit sandpaper all the speaker wires exiting the amp, then reinsert and try to twist them a little once inserted. The 'quick connect' features on many amps are famous for corrosion over time. If you have screw-on or universal binding post type speaker connections, it's not as likely, but still worth the same cleaning effort.

BTW, water in the speaker wires should be no problem, unless it causes enough corrosion to completely sever the conductor or unless it is somehow shorting through the insulation into the adjacent wire, providing an alternate current path. Not too likely in either case, I would suspect. (Not that i'd like to have water in my wires, lol) Water AT the speaker connection, either at the amp, or at the speaker, is probably not a good thing, and would likely be causing a whole bushel of other problems eventually.

Good Luck!

 

[SS MAYFLOAT]

Re: Audio equipment question

BTW, water in the speaker wires should be no problem, unless it causes enough corrosion to completely sever the conductor or unless it is somehow shorting through the insulation into the adjacent wire, providing an alternate current path. Not too likely in either case, I would suspect. (Not that i'd like to have water in my wires, lol) Water AT the speaker connection, either at the amp, or at the speaker, is probably not a good thing, and would likely be causing a whole bushel of other problems eventually.

Good Luck!

What I have been taught, electric runs on the outside surface of the wire. Not in the middle. That is why most audio cable has so many strands. It is to add as much surface area to the wire for the least resistance. If the wire has corrosion on the surface of it (especially audio cable), it will cause power loss.

 

[QuadManiac]

Re: Audio equipment question

What I have been taught, electric runs on the outside surface of the wire. Not in the middle. That is why most audio cable has so many strands. It is to add as much surface area to the wire for the least resistance. If the wire has corrosion on the surface of it (especially audio cable), it will cause power loss.

This is called 'skin effect'. See http://en.wikipedia.org/wiki/Skin_effect , and in almost all cases does not become an issue until you reach RF frequencies. Many speaker cable manufacturers have tried to tout skin effect as a sales point, but from the physics, it's bunk. Speaker wire is stranded to make it flexible. The majority of audio frequency signals pass through the bulk cross section of the individual strands. You will not notice a difference in sound quality or power delivered to the speaker, in most cases, whether you use stranded or solid conductor wire.

 

[bruceb58]

Re: Audio equipment question

I agree with QuadManiac...There have been many "A" "B" tests with Monster Cable vs regular speaker wire and not even avid audiophiles can tell the difference. The only difference between the expensive speaker wire and regular wire is one makes your wallet lighter. Skin effect in speaker wire is basically a marketing ploy.

 

[BoatBuoy]

Re: Audio equipment question

Geez, guys, QC ain't running Class A tube amps in his boat.