"John Byrns" wrote in message
...
In article
,
AB9GO wrote:

Speaker designed for use with amateur and two-way radio,
shortwave and
scanner listening.

http://www.soundssweet.com

Look at how it is constructed and buy the parts from
www.partsexpress.com
.
Here are reviews from hams that own this speaker:
http://www.eham.net/reviews/detail/2754

I don't know if I would trust that speaker to "sound
sweet", it is a
"tuned port, bass reflex speaker", and those tend to have
a peaky
resonant bass, not a sweet bass sound. They probably used
the "tuned
port, bass reflex" because the box would have had to be
larger than
their target size otherwise.


Regards,

John Byrns

Bass reflex cabinets are capabl of excellent
non-resonant bass but the cabinet and speaker must be
matched. A bass reflex cabinet is the acoustic equivalent of
a lumped constant impedance matching network of the L type.
At system resonance most of the output comes from the port.
If the loudspeaker Q is too low or if the system tuning
isn't right there will be a ringing at some bass frequency.
Properly designed the system is flat and has low distortion.
A lot of commercial ported enclosures are not really
bass reflex cabinets, just resonant boxes meant to give some
impression of bass where there really isn't any.
Speakers can be _too_ efficient for a bass reflex.
However, the cabinet can still extend the bass and reduce
bass distortion, however an electronic equalizing filter is
needed. All this stuff is in the literature.


--
---
Richard Knoppow
Los Angeles, CA, USA

On 1/26/08 12:49 AM, in article ,
"Don" wrote:

Many people
say the Alnico magnets give better sound than ceramic magnets, so look for
that. Since each speaker only gets 15 watts, they are designed for
efficiency instead of long throw, and fill an auditorium or basketball court
with ease.

Many people say a lot of things that have little basis in fact. There's
nothing in an alnico magnet that will make a speaker sound better. This myth
probably came from the fact that the early speakers with ceramic magnets
were cheap junk. They had no clue how to design a proper motor system using
ceramic, so the drivers were lousy. But by the late 70's, alnico got so
expensive that virtually everyone stopped using it and everyone went to
ceramic. Once they figured out how to properly use the magnets, the
performance was at least as good, if not better, than the alnico systems
they replaced. And even if alnico magnets have slightly better immunity to
flux modulation, a modern ceramic magnet system can be designed to work just
as well. Alnico also has the distinct disadvantage of being susceptible to
demagnetization from the voice coil. By any objective standard, today's
speakers with ceramic magnets absolutely trounce anything made with alnico
back then. And btw, today the Chinese have a monopoly on alnico, and it's
more expensive than ever.

wrote in message
...
I like listening to shortwave and ham stuff using biggish speakers.
Little speakers like computer speakers sound chintzy to my ears.

As examples, I have an old 50's Caliphone record player/PA system that
has two remote 15" speakers and I just love the way my shortwave and
ham stuff sounds through these speakers. I also have some Electovoice
EV5's (again, big old mellow speakers) and I love the way things sound
through these.

If you want to build your own baffle or case, maybe you'd like to try a Quam
8C10FEPAXB. 8" coaxial (i.e. has whizzer cone), 40-20,000 Hz, 97 dB spl
(1w/1m), 8 ohms. $14.16 from http://www.tselectronic.com

On Jan 25, 7:35*am, " sho...@trailing-
edge.com wrote:
I like listening to shortwave and ham stuff using biggish speakers.
Little speakers like computer speakers sound chintzy to my ears.


I seem to come across lots of good deals on radio-phono combinations -
the typical late 40's or 50's radio phono in a squarish cabinet.
Passed one up lat weekend , 20 dollars , complete, with eye tube.
this is typical of them because no collector needs yet another one of
these. even the 60's transistor sets- same thing - can't give them
away.

but for parts, lots of good transformers, tubes, large speakers can be
had for a reasonable price usually.
you could buy one of these and modify the cabinet to suit your need
for a box to put it in, just re-use the speaker and cloth and cut the
box down to suit.

I hate destroying these things, because lots of enjoyment can be had
with them, but for large speakers, I dont' see why there is much
demand for those..

smaller speakers , like one would find in a tombstone or cathedral,
now that is a different story..
Phil

On Jan 25, 10:35*am, " sho...@trailing-
edge.com wrote:
I like listening to shortwave and ham stuff using biggish speakers.
Little speakers like computer speakers sound chintzy to my ears.

As examples, I have an old 50's Caliphone record player/PA system that
has two remote 15" speakers and I just love the way my shortwave and
ham stuff sounds through these speakers. I also have some Electovoice
EV5's (again, big old mellow speakers) and I love the way things sound
through these.

But I don't want to undo my record player setup or stereo system setup
to borrow the speakers. If I wanted a new speaker with similar
qualities - nothing fancy, just a big speaker in a big wood box -
where would I look? Would a guitar amp speaker (something I can buy at
a guitar store?) be the right thing for me to buy?

Going into Short Circuit City or Radio Shack I don't see anything that
really seems like what I want. I did get a couple of Radio Shack patio
speakers (5 inch drivers in a metal box) and those are better than
anything else new I've found, but they still don't sound mellow enough
and still a bit tinny. They're sort-of listenable and I've been using
them for a while but their tinny is kinda grating after a while. I
want big and mellow. Where do I go and what do I ask for?

Tim.

Something like these?
http://cgi.ebay.com/Two-12-PM-speake...QQcmdZViewItem

On Jan 25, 10:35*am, " sho...@trailing-
edge.com wrote:
I like listening to shortwave and ham stuff using biggish speakers.
Little speakers like computer speakers sound chintzy to my ears.

As examples, I have an old 50's Caliphone record player/PA system that
has two remote 15" speakers and I just love the way my shortwave and
ham stuff sounds through these speakers. I also have some Electovoice
EV5's (again, big old mellow speakers) and I love the way things sound
through these.

A little bit more insight: I went shopping for speakers and found that
almost all 12" speakers have a natural responsive range of a little
under 100Hz to a little over 3kHz when installed in a simple box (no
ports. etc.)

This is, through no strange coincidence, exactly the frequency range
that I want to listen to :-).

I ended up picking a 12" Jensen musical instrument speaker which
seemed to have a frequency response curve remarkably like all the
other 12" speakers out there. There were some 12" PA speakers but
those seemed to be aimed at power handling capabilities in the
hundreds of watts (approaching a kilowatt!) and price kept me away
from them (although it's very likely they would work as well and
probably stand up to nearly infinite abuse.)

For non-hi-fi radio listening, I think there's a perfect match going
on there. I feel (no proof, just my ears) that hi-fi speakers that try
to go higher than a few kHz are reproducing stuff coming out of my
radio that I never wanted to hear to begin with.

Looking at it, I have a hard time seeing how chintzy little computer
speakers can legibly reproduce speach etc. at all! I'm guessing they
don't get any flat response at all over the fundamentals of male
speech and are only good on the harmonics. Maybe in a perfect world
that's you need for legible reproduction but with all the noise and
scratch on the HF bands it does not cut the mustard with my ears.

Tim N3QE