02-27-2013, 08:41 PM
Now let's bring in the woofer. It has a frequency response of 20 to 6000 Hz.
[Image: http://www.philcoradio.com/images/phorum...430c5e.jpg]
[Image: http://www.philcoradio.com/images/phorum...79a0de.jpg]
This thing is as big as several of my radios and even bigger than others!
With a woofer response of 20 - 6000 Hz and a tweeter response of 3000-20000 Hz, using a crossover network with a crossover point of 4500 Hz, this speaker will produce the full audible range of 20 to 20,000 Hz. Certainly the radio will not be producing that kind of frequency response on AM or SW, although the McMurdo's audio amp is probably capable of producing that entire frequency range. Once the set is done, playing something through the McMurdo's microphone input should prove interesting.
Anyway, the next step is to mount the tweeter coaxially in the middle of the woofer. I found that by simply laying the arms on the woofer gasket and tightening the screws/nuts, that the steel sank down into the gasket, making the steel rub against the outer accordion edge of the woofer's cone - not good.
Then I remembered these:
[Image: http://www.philcoradio.com/images/phorum...1a7e5a.jpg]
Nylon washers that I had bought at a hardware store, that turned out to be too big for use in lamp sockets. But now I can use them as spacers:
[Image: http://www.philcoradio.com/images/phorum...476a19.jpg]
These will keep the steel arms from sinking into the woofer's gasket and will keep the arms suspended above the woofer's accordion edge!
Finally, here's how the homemade coaxial speaker looks all together:
[Image: http://www.philcoradio.com/images/phorum...a2d482.jpg]
[Image: http://www.philcoradio.com/images/phorum...324b3f.jpg]
[Image: http://www.philcoradio.com/images/phorum...f99211.jpg]
The next step is to attach wires to both speakers, then attach the speaker inside the McMurdo's Clifton cabinet. I bought some stick-on gasket material to help ensure a tight seal between speaker and sounding board, and I'll be using some of this when I put the speaker in the cabinet.
[Image: http://www.philcoradio.com/images/phorum...430c5e.jpg]
[Image: http://www.philcoradio.com/images/phorum...79a0de.jpg]
This thing is as big as several of my radios and even bigger than others!
With a woofer response of 20 - 6000 Hz and a tweeter response of 3000-20000 Hz, using a crossover network with a crossover point of 4500 Hz, this speaker will produce the full audible range of 20 to 20,000 Hz. Certainly the radio will not be producing that kind of frequency response on AM or SW, although the McMurdo's audio amp is probably capable of producing that entire frequency range. Once the set is done, playing something through the McMurdo's microphone input should prove interesting.
Anyway, the next step is to mount the tweeter coaxially in the middle of the woofer. I found that by simply laying the arms on the woofer gasket and tightening the screws/nuts, that the steel sank down into the gasket, making the steel rub against the outer accordion edge of the woofer's cone - not good.
Then I remembered these:
[Image: http://www.philcoradio.com/images/phorum...1a7e5a.jpg]
Nylon washers that I had bought at a hardware store, that turned out to be too big for use in lamp sockets. But now I can use them as spacers:
[Image: http://www.philcoradio.com/images/phorum...476a19.jpg]
These will keep the steel arms from sinking into the woofer's gasket and will keep the arms suspended above the woofer's accordion edge!
Finally, here's how the homemade coaxial speaker looks all together:
[Image: http://www.philcoradio.com/images/phorum...a2d482.jpg]
[Image: http://www.philcoradio.com/images/phorum...324b3f.jpg]
[Image: http://www.philcoradio.com/images/phorum...f99211.jpg]
The next step is to attach wires to both speakers, then attach the speaker inside the McMurdo's Clifton cabinet. I bought some stick-on gasket material to help ensure a tight seal between speaker and sounding board, and I'll be using some of this when I put the speaker in the cabinet.
--
Ron Ramirez
Ferdinand IN
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