# Would an audio test CD help trouble shoot a rattling noise in speaker?

E

#### eastcoastguyz

Jan 1, 1970
0
(Please be kind, I am not an audio expert.)

I have a TV which makes a rattling noised when certain low frequencies
are played at a normal volume. This happens from either cable or
playing something from a DVD. Before I remove the cover and start to
try tightening screws up and other things, I would like to be able to
duplicate the problem while attemping to fix this problem.

I thought perhaps this could be done with an audio test CD I have
heard about. I was thinking I would play it through the DVD player
connected to the TV, and then when it makes the rattled, know that I
have isolated it to begin to fix this.

I don't know if I would have any other use for a $100 audio test CD beyond this purpose, so I was wondering if there already exists some audio test samples that are free I could download someplace that would do the trick. The rattle doesn't happen often enough to simply leave the TV on while trying to duplicate the problem. I don't know how low of a frequency it is, just that it is low when it rattles. This is just a normal JVC TV, no surround sound or anything additional added to it. Thanks! M #### Mr.T Jan 1, 1970 0 eastcoastguyz said: I have a TV which makes a rattling noised when certain low frequencies are played at a normal volume. This happens from either cable or playing something from a DVD. Before I remove the cover and start to try tightening screws up and other things, I would like to be able to duplicate the problem while attemping to fix this problem. Fairly common for the small cheap speakers used in most TV's to rattle when any significant bass levels are attempted. I thought perhaps this could be done with an audio test CD I have heard about. I was thinking I would play it through the DVD player connected to the TV, and then when it makes the rattled, know that I have isolated it to begin to fix this. Why not just use one of the DVD's you are already having trouble with? Turn up the volume, and bass controls if your TV has them. Plug the subwoofer output from the DVD player into the TV audio inputs if you can, then play almost any action movie with lots of low frequency rumble. I don't know if I would have any other use for a$100 audio test CD
beyond this purpose, so I was wondering if there already exists some
audio test samples that are free I could download someplace that would
do the trick. The rattle doesn't happen often enough to simply leave
the TV on while trying to duplicate the problem. I don't know how low
of a frequency it is, just that it is low when it rattles. This is
just a normal JVC TV, no surround sound or anything additional added
to it. Thanks!

Can you plug your computer sound output into the TV audio input? Then you
need a sinal generator/oscillator program that you can adjust the frequency
to find the worst resonance frequencies for the TV speaker. But yes you
could also make your own test CD's for nothing using a program like
Audacity. A low frequency sweep signal is usually helpful.

Frankly I find simply tightening the speakers and packing any plastic
surrounds with rubber to stop vibration helps, unless you want to really fix
the problem by using much better external speakers. That always works for
me.

MrT.

H

#### Homer J Simpson

Jan 1, 1970
0
(Please be kind, I am not an audio expert.)
OK.

I have a TV which makes a rattling noised when certain low frequencies
are played at a normal volume.
I thought perhaps this could be done with an audio test CD I have

No point - wouldn't help. The usual way is to feed 3 VAC into the audio
system and look for the rattle. Failing that, you need an audio generator to
drive the system.

T

#### Trevor Wilson

Jan 1, 1970
0
eastcoastguyz said:
(Please be kind, I am not an audio expert.)

I have a TV which makes a rattling noised when certain low frequencies
are played at a normal volume. This happens from either cable or
playing something from a DVD. Before I remove the cover and start to
try tightening screws up and other things, I would like to be able to
duplicate the problem while attemping to fix this problem.

I thought perhaps this could be done with an audio test CD I have
heard about. I was thinking I would play it through the DVD player
connected to the TV, and then when it makes the rattled, know that I
have isolated it to begin to fix this.

I don't know if I would have any other use for a $100 audio test CD beyond this purpose, so I was wondering if there already exists some audio test samples that are free I could download someplace that would do the trick. The rattle doesn't happen often enough to simply leave the TV on while trying to duplicate the problem. I don't know how low of a frequency it is, just that it is low when it rattles. This is just a normal JVC TV, no surround sound or anything additional added to it. Thanks! **No need to shell out big Bucks on a test CD. Just burn your own. Here is a freeware package which should allow you to do just that: http://www.dr-jordan-design.de/signalgen.htm Just dial up a low frequency (say 50Hz) and test. D #### Dave Plowman (News) Jan 1, 1970 0 N #### N Cook Jan 1, 1970 0 eastcoastguyz said: (Please be kind, I am not an audio expert.) I have a TV which makes a rattling noised when certain low frequencies are played at a normal volume. This happens from either cable or playing something from a DVD. Before I remove the cover and start to try tightening screws up and other things, I would like to be able to duplicate the problem while attemping to fix this problem. I thought perhaps this could be done with an audio test CD I have heard about. I was thinking I would play it through the DVD player connected to the TV, and then when it makes the rattled, know that I have isolated it to begin to fix this. I don't know if I would have any other use for a$100 audio test CD
beyond this purpose, so I was wondering if there already exists some
audio test samples that are free I could download someplace that would
do the trick. The rattle doesn't happen often enough to simply leave
the TV on while trying to duplicate the problem. I don't know how low
of a frequency it is, just that it is low when it rattles. This is
just a normal JVC TV, no surround sound or anything additional added
to it. Thanks!

Its surprising how much distortion can be due to just a paper clip or bit of
machining swarf touching the cone and attracted by the magnet. Try a
different speaker on the same feed is my suggestion.

M

#### Mark D. Zacharias

Jan 1, 1970
0
eastcoastguyz said:
(Please be kind, I am not an audio expert.)

I have a TV which makes a rattling noised when certain low frequencies
are played at a normal volume. This happens from either cable or
playing something from a DVD. Before I remove the cover and start to
try tightening screws up and other things, I would like to be able to
duplicate the problem while attemping to fix this problem.

I thought perhaps this could be done with an audio test CD I have
heard about. I was thinking I would play it through the DVD player
connected to the TV, and then when it makes the rattled, know that I
have isolated it to begin to fix this.

I don't know if I would have any other use for a $100 audio test CD beyond this purpose, so I was wondering if there already exists some audio test samples that are free I could download someplace that would do the trick. The rattle doesn't happen often enough to simply leave the TV on while trying to duplicate the problem. I don't know how low of a frequency it is, just that it is low when it rattles. This is just a normal JVC TV, no surround sound or anything additional added to it. Thanks! Don't remember what web site but I was able to download a couple drum samples which greatly aided my troubleshooting once. The piece I was working on didn't even act up using sine waves, only when lower frequency music was being played. Maybe Google "download drum sample" and see what you find. Mark Z. D #### Dave Plowman (News) Jan 1, 1970 0 Don't remember what web site but I was able to download a couple drum samples which greatly aided my troubleshooting once. The piece I was working on didn't even act up using sine waves, only when lower frequency music was being played. The best check is a warbling sweep. Check out the one I suggested earlier. That's what speaker makers use. G #### GregS Jan 1, 1970 0 The best check is a warbling sweep. Check out the one I suggested earlier. That's what speaker makers use. Sine waves can detect resonances. I have always used low bandwidth music,(AM radio) to shake up rattles in the higher registers. All you have to do is turn the switch and work the knobs, or buttons. greg D #### Dave Plowman (News) Jan 1, 1970 0 Sine waves can detect resonances. I have always used low bandwidth music,(AM radio) to shake up rattles in the higher registers. All you have to do is turn the switch and work the knobs, or buttons. Trouble is you can't *guarantee* random music will have the correct frequencies to show up a rattle etc. Hence the idea of using a repeatable test. The beauty of the 'warble' is going either side of the spot frequency tends to excite any resonance more readily. M #### Mr. Land Jan 1, 1970 0 (Please be kind, I am not an audio expert.) I have a TV which makes a rattling noised when certain low frequencies are played at a normal volume. This happens from either cable or playing something from a DVD. Before I remove the cover and start to try tightening screws up and other things, I would like to be able to duplicate the problem while attemping to fix this problem. I thought perhaps this could be done with an audio test CD I have heard about. I was thinking I would play it through the DVD player connected to the TV, and then when it makes the rattled, know that I have isolated it to begin to fix this. I don't know if I would have any other use for a$100 audio test CD
beyond this purpose, so I was wondering if there already exists some
audio test samples that are free I could download someplace that would
do the trick. The rattle doesn't happen often enough to simply leave
the TV on while trying to duplicate the problem. I don't know how low
of a frequency it is, just that it is low when it rattles. This is
just a normal JVC TV, no surround sound or anything additional added
to it. Thanks!

How old is the TV?

I've seen really old ones where the cement used to adhere the speakers
voice coil wire to the paper cylinder has deteriorated with age such
that some of the windings come loose now float around, scraping
against the other parts of the speaker. This is especially audible at
lower freqs. I'd bet that's what it is.

M

#### mark

Jan 1, 1970
0
Mr. Land said:
How old is the TV?

I've seen really old ones where the cement used to adhere the speakers
voice coil wire to the paper cylinder has deteriorated with age such
that some of the windings come loose now float around, scraping
against the other parts of the speaker. This is especially audible at
lower freqs. I'd bet that's what it is.
Why not just try another speaker if it's old a lot of times the cone is
torn or the speaker is just bad in some way.

B

#### Bennett Price

Jan 1, 1970
0
If the TV has an optional audio input, I'd suggest just plugging in an
audio cable, turning up the volume, and put your thumb on the center
prong of the audio cable. This should generate a loud hum that is
likely to reveal the source of the rattle. (If you don't have a cable,
stick a small screwdriver in the audio input and touch it with your
finger while jiggling it around a bit.)

J

#### Jeroni Paul

Jan 1, 1970
0
I had a similar problem, it had that flex thing that surrounds the
speaker cone broken. It was of some aged material that fell off just
blowing air at it. Fixed it with fine paper adhesive.

Replies
4
Views
647
D
Replies
6
Views
4K
rickman
R
D
Replies
4
Views
937
David
D
E
Replies
45
Views
8K
Eeyore
E
N
Replies
20
Views
2K
Phil Allison
P