Newbie: speaker cuts out

Archived from groups: rec.audio.tech (More info?)

The centre channel speaker (Infinity brand) on my home stereo often cuts out
when the volume is turned down too low. I turn the volume up a bit and I can
hear it again. I've tried reseating the speaker wires on the amp end and the
speaker end but the problem really never goes away. What's my most likely
culprit? Amp, Speaker or wires? Is this common? How would I test it? I own a
volt-ohm meter. Thx.

Archived from groups: rec.audio.tech (More info?)

Thanks.

"John A. Weeks III" <john@johnweeks.com> wrote in message
news:john-8EA42D.06153323032005@ip-lcc.supernews.net...
> In article <OK60e.761637$6l.431678@pd7tw2no>,
> "Alan Smithee" <AlanSmithee@nowhere.com> wrote:
>
> > The centre channel speaker (Infinity brand) on my home stereo often cuts
out
> > when the volume is turned down too low. I turn the volume up a bit and I
can
> > hear it again. I've tried reseating the speaker wires on the amp end and
the
> > speaker end but the problem really never goes away. What's my most
likely
> > culprit? Amp, Speaker or wires? Is this common? How would I test it? I
own a
> > volt-ohm meter. Thx.
>
> We have to figure out if it is the speaker, speaker wire, or
> your receiver. The easy way to do this is swap the center
> and left channel at the receiver. Now play the system for
> a while. Does the center speaker (now playing the left
> channel sound) still cut out? If so, it is the speaker
> or speaker wire. Replace the wire. If that doesn't do it,
> then you have a bad speaker.
>
> If the cut out moved to the left channel speaker (which is
> now playing the center sound), you have a problem somewhere
> between the program material and the receiver. It could be
> a bad DVD player, a bad RCA cable, a bad connection at one
> of the cable ends, or a bad receiver. It could be the
> volume control itself. You can get a can of control cleaner,
> pop the cover on the receiver, unplug the unit, then spray
> the cleaner into each section of the volume control while
> twisting the volume knob.
>
> -john-
>
> --
> ======================================================================
> John A. Weeks III 952-432-2708 john@johnweeks.com
> Newave Communications http://www.johnweeks.com
> ======================================================================

Archived from groups: rec.audio.tech (More info?)

Thankfully the problem turned out to be much more banal than even I could
have imagined. Once I got up the nerve to open the speaker I noticed the
male/female automotive type connector plugs which join the speaker cable
"grab" mechanism to the cross over circuitry looked loose. They were encased
in what looked like rubber cement, probably to avoid oxidation. As I removed
the rubber cement the female part of the push connectors literally fell
apart inside the rubber cement compound. I'm guessing the cheap brass
connectors were corroded by something in the rubber cement like compound
meant to protect them from oxidation. Five minutes of soldering later my
centre channel is as good as new. Thanks for the insights though.


"Barry Mann" <zzzz@zzzz.zzz> wrote in message
news:42419a06$1$avgroveq$mr2ice@wcnews.cyberonic.com...
> In <OK60e.761637$6l.431678@pd7tw2no>, on 03/23/05
> at 05:01 AM, "Alan Smithee" <AlanSmithee@nowhere.com> said:
>
> >The centre channel speaker (Infinity brand) on my home stereo often
> >cuts out when the volume is turned down too low. I turn the volume up
> >a bit and I can hear it again. I've tried reseating the speaker wires
> >on the amp end and the speaker end but the problem really never goes
> >away. What's my most likely culprit? Amp, Speaker or wires? Is this
> >common? How would I test it? I own a volt-ohm meter. Thx.
>
> Somewhere you have a bad connection. Turning up the volume causes a
> tiny little spark that propels some metal across the gap, creating a
> fragile, temporary repair. Most likely the problem is between the
> receiver's internal power amplifier and the speakers.
>
> As another poster suggested, methodically changing something. If, when
> you swap the center speaker wiring with another channel at the back of
> the receiver, the problem moves to the speaker now connected to the
> center, then the center channel speaker and its wire are not the
> problem.
>
> ---
>
> A very common mid life failure is inside the protection relay inside
> your receiver. This relay is responsible for keeping the speakers
> disconnected from the receiver's amplifier while the amplifier powers
> up, shuts down, or if there is an amplifier failure. Ultimately, the
> best fix for this failure is replacing the relay. Most of these relays
> are enclosed in a plastic housing. Sometimes one can open the housing
> and mechanically clean the contacts. Cleaning is not always a practical
> option because some relays were never designed to be opened, some relay
> contacts are fragile and may damaged by the cleaning process, and some
> relays are very difficult to reach and properly clean. For the
> difficult to reach relays, professional service is probably the best
> route. In this case, by the time you've paid the technician to access
> the relay, there is little additional cost to simply replace it. Also,
> you don't want to disassemble a unit very often.
>
> The new relay will last approximately as long as the original.
>
> I've struggled with different techniques over the years. I started by
> cleaning them and some relays responded well and the cleaning lasted
> for the remaining life of the unit. Cleaning didn't always work for
> long and customers were disappointed and annoyed. If I considered the
> value of my time giving a lengthy explanation of the problem, options,
> and general discussion of why the cleaning didn't last long as the
> customer thought it should, it was cheaper to replace the relay without
> any discussion. And, after cleaning, if the unit came back in a short
> while, the customer would expect me to solve the situation at no or low
> cost. For some customers "a short while" was a year or two or three.
>
> At this point I hope the customer will call me first because I can
> suggest a home remedy that usually solves the problem, gives the
> customer some control over the situation, gives me some excellent
> diagnostic information -- and creates a loyal future customer who gives
> plenty of recommendations. I've also learned that this type of problem
> often temporarily resolves itself on the way to the shop. By the time I
> get my hands on the unit it is working fine and I have to guess what
> might be or have been wrong.
>
> ---
>
> Introducing "flash cleaning" of the protection relay:
>
> Switch on a highly compressed source. I typically use a local rock
> music station. In your case, force the tuner into MONO and use DOLBY
> PRO LOGIC. Most or all of the sound will be directed to the center
> speaker. Turn the volume up to just below the point where you will
> destroy something if you go any higher. While the music is playing at
> this near destruction level, turn off the power. It is critical for the
> process that the speaker be bellowing at the instant power is removed.
> Repeat the above 20-30 times. Note that the receiver does not need to
> sustain these levels, a fraction of a second is all that is needed. The
> units typically don't heat-up much during this process, but if you are
> nervous, you can stretch out the process.
>
> Physically, you are creating a small spark at the instant the relay
> contacts open. This miniature plasma will burn off surface
> contamination, "soften" the relay contact a bit, and restore operation.
> While this is not always a permanent repair (remember, even the
> replacement relay will fail again), it will usually restore proper
> operation for at least a few months, usually longer. In the future, if
> the problem returns, repeat the above.
>
> In addition to saving everyone a needless trip to the shop (or even
> pulling the unit off the shelf if you are the DIY type), the above
> procedure is an excellent diagnostic. If the unit responds to flash
> cleaning, assume it's a relay issue. While there are a few other
> possibilities, I rarely see them. (And it's always the same models that
> behave like they have a protection relay problem when it's something
> else. Unfortunately, its a tedious, messy fix for these few models.)
>
> Flash cleaning is not a panacea, but over the long haul it has proven
> to be more effective than mechanical cleaning -- and it is much safer
> -- considering all the accidents and mix-ups that can happen while the
> unit is disconnected, transported to and from the service center, then
> reconnected.
>
> -----------------------------------------------------------
> spam: uce@ftc.gov
> wordgame:123(abc):<14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
> 13> (Barry Mann)
> [sorry about the puzzle, spammers are ruining my mailbox]
> -----------------------------------------------------------
>