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Old 02-16-2012, 01:31 PM
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Jeffhs Jeffhs is offline
<----Zenith C845
 
Join Date: Feb 2003
Location: Fairport Harbor, Ohio (near Lake Erie)
Posts: 4,035
Bryan -

Most of today's flat-panel TVs have headphone/earphone jacks that shut the speakers off when headphones are plugged in. This jack cannot be used with non-amplified speakers, as the output level at the headphone jack is attenuated to prevent or minimize hearing damage. I found this out when I recently tried to connect a pair of unamplified computer speakers to the headphone jack of my flat-screen TV -- the sound was so low I could barely hear it, even at full volume. However, the jack works as intended with headphones, of course.

If your uncle is using the RCA audio output jacks on his TV, they should work even with wireless headphones, since these jacks are meant to be connected to external audio systems; they should have plenty of signal to drive the wireless phones to full volume. Has he tried testing the wireless phones with another device, such as a stereo system or other audio source with a line-output jack? I'd try this: Connect the audio input of the stereo phones' base unit to the output jacks on the external amplifier; if the wireless phones now work with reasonable volume, the problem is likely somewhere in the TV's audio system. However, before doing anything drastic I'd check all connections first, to be sure they are all connected to the correct inputs and outputs. Be absolutely sure these are correctly and securely connected, as a short or loose connection anywhere in the system can lead to severe damage to the TV's audio system.

I had (and still have in storage) an RCA CTC-185 table-model TV that does not have its own audio input/output or external speaker jacks; the only safe way to connect external speakers to this set (probably any RCA TV in the CTC1xx series or, for that matter, any late-model TV of any make) is to connect them through an external amplifier, say the audio output jack(s) on a VCR or DVD player, or the amplifier or receiver in a home-theater system; even the audio outputs of any bookshelf system will work. I have a 200-watt (50 watts x4 channels) Aiwa bookshelf system to which I intend to connect my flat TV eventually; just haven't gotten around to it yet, and to be honest, most of the shows I watch on a regular basis (on PBS, MeTV/Antenna TV and the news, to say nothing of old reruns on DVD) would not sound any better in 200-watt surround sound than they presently do through the TV's own speakers.

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Do not try to connect external speakers across (in shunt with) or in place of the set's internal ones, as most sets in the CTC1xx series are of "hot chassis" design. This does not mean external speakers will not work with this TV; however, it does mean that one must be extremely careful not to short the speaker terminals together or to ground -- this will result in severe and permanent damage to the set. It is much better and safer to use an external amplifier to which your external speakers are connected.

BTW, I personally think stereo sound in most TVs -- both the new flat sets and the older stereo NTSC ones (like high-end Zenith, et al. consoles of the '80s and '90s) -- is a joke, considering the tiny transistor-radio speakers they have. (My Insignia flat screen is even worse, since its tiny speakers are mounted on the back of the set, meaning the sound will be muffled or weakened unless the TV is placed in a corner or against a wall; I wonder what the designers were thinking?)

Moreover, most "stereo" TVs, even consoles and certainly portables/table sets, are nowhere near wide enough to provide adequate stereo separation, so the MTS stereo feature of most if not all TVs, NTSC consoles/table sets or flat screens, is an unnecessary frill -- unless of course one connects the audio outputs to a decent sound system. Just my own opinion.
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Collecting, restoring and enjoying vintage Zenith radios since 2002

Zenith. Gone, but not forgotten.

Last edited by Jeffhs; 02-16-2012 at 10:50 PM.
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