"hwh" wrote in message
...

"Chris Paulson-Ellis" schreef in bericht
.. .
Hello,

I'm considering buying a Teac 300DAB mini system

If you're going to use it to listen to DAB it does not matter at all what
kinf of speakers you use.
DAB is not hi-fi.

gr, hwh

I seem to remember this type of comment in the vinyl v cd debate :-)
Unfortunately I have had DAB for 5 years. The quality is crap.

Terry

PS I prefer cds to vinyl.

45 watts into 6.5 ohms means the amplifier can produce a signal of 17v
RMS.

Why not connect an AC voltmeter across your speaker terminals, and see
what
signal level you're using? If it's less than 17v, the new amplifier will
drive your speakers as loud as your existing amplifier.

Tim Martin


Well, I tested this myself. and it doesn't work with my voltmeter.

I connected an oscilloscope and a voltmeter across the speaker terminals,
and tested out the readings with a few sine waves (100Hz, 500Hz, 1000Hz).
The voltmeter and oscilloscope readings matched exactly, with the peak
voltage on the oscilloscope at 1.4 times the voltmeter reading..

However, on music, the match failed. The peak voltage on the oscilloscope
was about 4 times the voltmeter reading. The problem seems to be that the
voltmeter doesn;t track signal level changes fast enough.

Oh well ...

Tim martin

On Tue, 26 Apr 2005 01:52:41 GMT, "Tim Martin"
wrote:

45 watts into 6.5 ohms means the amplifier can produce a signal of 17v
RMS.

Why not connect an AC voltmeter across your speaker terminals, and see
what
signal level you're using? If it's less than 17v, the new amplifier will
drive your speakers as loud as your existing amplifier.

Tim Martin


Well, I tested this myself. and it doesn't work with my voltmeter.

I connected an oscilloscope and a voltmeter across the speaker terminals,
and tested out the readings with a few sine waves (100Hz, 500Hz, 1000Hz).
The voltmeter and oscilloscope readings matched exactly, with the peak
voltage on the oscilloscope at 1.4 times the voltmeter reading..

However, on music, the match failed. The peak voltage on the oscilloscope
was about 4 times the voltmeter reading. The problem seems to be that the
voltmeter doesn;t track signal level changes fast enough.

It's called 'crest factor'. Your voltmeter will be calibrated to read
correctly the average value of a sine wave, hence tyhe good
correlation on sines. However, music has a much higher ratio of pk-pk
to rms value, technically known as crest factor. You need the 'scope
to check what peak voltage you need for your preferred listening
level.
--

Stewart Pinkerton | Music is Art - Audio is Engineering