[1000mp] Speaker Choice - Not HiFi

[WD8ARZ]

Thanks for bring up your point Mac, had the same thoughts in my mind. I tend
to use communications grade stereo headphones a lot my self. I the shack I
will use a pair of HS-1661 Communications grade speakers. When roaming
around the house and outside I use wireless head phones, and wireless
speakers depending on circumstances .... and never do I use music and hifi
speakers for my communications receivers.

A hifi speaker being fed by a narrow bandwidth audio amp output doesn't make
sense of course. Not only is the frequency range of the speaker not
supported by the receiver audio, but your also doing a dis-service to the
signal to noise ratio for the intelligibility portion of the voice audio
that you really want ..... plus the hifi speakers are giving more output to
the low end bass where voice intelligibility is not at .... and the static
crashes are at .... the end result is a much harder to understand human
voice, especially during summer static.

I use Heathkit HS-1661speakers that are tailored for the intelligible range
of human speech .... ends up being easier to understand the output, and with
a better more fatigue free listening to boot. That's what communications
grade speakers are meant to do. Speakers meant for HiFi Stereo are not
communications grade speakers.

Some may have forgotten that transmitted audio puts most of its power in the
low frequencies, but we need the higher frequencies to make out the spoken
word mixed in with noise.... with less power in the high frequencies, range
is reduced.
That's why the dxer higher frequency punch is used and the lows trimmed
...... now the power that was being put into the low frequencies that don't
contribute so much to understandability, is going to the higher range where
it is needed for better readability.

Under strong signal conditions, AM signals on large wider frequency range
speakers can seem to be nicer and thus the way to always go for listening
under all conditions, and that is simply not true of course. Some using the
legally questionable wide 6khz sideband, and pushing low frequency audio
trying to emulate AM audio quality, are actually a step backwards for what
Ssb communications is all about... ...which is improving range and
intelligibility using less power than the same AM signal (AM as in double
sideband with carrier, of course single side band is also AM) AND less band
space.

Reducing the noise and keeping the audio frequency range to the
intelligibility range, also improves the spatial processing of our brain
processor when using dual receiver and diversity mode reception techniques.

73 from Bill - WD8ARZ
wd8arz@ix.netcom.com

----- Original Message -----
From: "J. Mc Laughlin" <jcm@power-net.net>
To: <1000mp@mailman.qth.net>
Sent: Saturday, March 30, 2002 23:08
Subject: Re: [1000mp] Speaker Choice


> I have been puzzled by this thread.  I can not understand why one would
> use a speaker at all with the radio.  Some assumption is not being
> stated.
>
> A pair of headphones with one receiver connected to one side, and the
> other receiver connected to the other side, seems to be the natural way
> for a human to process aural signals.  I understand that some are using
> two speakers.
>
> Signal to noise ratio is the game.  How does a loudspeaker help SNR?
> One would expect extraneous sounds to degrade SNR.
>
> Presumably other persons are about.  One would expect the sound from
> loudspeakers to tend to be disturbing to others.
>
> Teach me what benefit accrues from the use of loudspeakers.     73
> Mac   N8TT
>
> J. Mc Laughlin  -  Michigan USA
> Home:  JCM@Power-Net.Net
> Office:  JCM@McLMcL.Com