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Old January 30th 12, 07:27 PM posted to rec.radio.amateur.boatanchors
Scott Dorsey Scott Dorsey is offline
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First recorded activity by RadioBanter: Jul 2006
Posts: 774
Default Speaker and DSP for boatanchor receivers

Cadiscase wrote:
If I wanted to buy a NEW 3.2 ohm speaker to use with a Hammarlund radio is there one that anyone would recommended for listening to AM broadcasts?
Is there any recommended size speaker such as 6 inch or 8 inch, etc?


I would suggest you look at the Quam 8-inch full range speakers. The
8-ohm ones are fine.

The good news is that if you have a full-range speaker, the larger they get
the lower the low end corner can be, because they can move more air. But the
larger they get, the more high frequency breakup problems you have. The
8-inch drivers are very common since they are used in cheap distributed PA
systems.

Is there any loss in audio quality using a 4 ohm speaker?


No, because the speaker impedance is all over the place. In fact, I would
suggest just using an 8-ohm driver and losing 3 dB of maximum level.

How would two 8 ohm speaker in parallel work?


You'll get interference issues... you'll hear phasing differences when you
move your head because you can't put the two speakers at exactly the same
point in space. An 8-ohm speaker and an 8-ohm power resistor in parallel
would be fine.

Is anyone using a DSP unit with their boatanchor which they would recommend?
Most [All ?] DSP units distort the audio so there is probably always some distortion, but some DSP units would be better than others. I am thinking in term of AM signals broadcast band reception.


You may look at some of the older JPS Communication DSP units. My guess is
that for BC listening, the only really useful DSP feature aside from noise
limiting is heterodyne elimination, and the JPS units were good at that.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."