Heather's Blogpile

As part of my biamp project, I recently bought an old Crown D-75 off eBay. Seller said the Amp was in good shape, and I trust people at their word. I have bought and sold parts via eBay - I sold a pair of Triumph motorcycle forks, and a pair of JBL 4312 speakers - big heavy things, I padded and packed them tightly and they got to the buy on the west coast just fine.

When the Crown amp arrived a few weeks later, I was just amazed. Somehow the seller decided to use a box for a DELL flatscreen monitor and the original white foam for the monitor as packing material for the heavy amp. As you can see in the pictures, this didn't fill the box and there was no extra foam/ bubblepack or anything to hold the amp in place. It must have bounced all over the place because it broke up the foam and bashed a hole in the package. Thats not UPS's fault - its the seller's fault for doing such a poor job of packing.

I hooked the amp up to my speakers and it works fine, but I give all the credit to Crown for making a bulletproof amp, not to this yahoo seller who apparently just used his old computer trash/packing to ship a $130 amp! Amazing!

Posted by Heather at 5:30 PM | Permalink | Comments (0)

My old (early 70s) JBLs are big box 3 ways - 15" woofer, 1" horn midrange, and a slot tweeter. I'm currently running them with my aging JVC AV receiver - its a nice unit, but it doesn't provide much headroom for the woofers. JBLs are very efficient speakers - it doesn't take a lot of power to run tweeters or mid-range horns, but woofers are power eaters in a decent system, and big woofers are worse. You see, speakers make music by moving air, and it takes lots of power to move a big speaker cone.

Another reason for more power is dynamic range - thats the difference in volume (sound level) between a quiet sound and a louder sound. Your speaker may play fine in normal use, but you need more power to play cleanly with a dramatic change in volume like the cannons in the 1812 Overture, (or "bullet time" in The Matrix).

The best audiophile technique is to give each driver in the speaker its own amp, but that can get real pricey. Second best is to feed the woofers with a more powerful amp, and use a medium powered amp for the midrange (MF) and tweeters (UHF). Thats the approach I've decided to take.

Through ebay and some other sources, I've started collecting the parts that will allow me to biAmp my speakers. From one of the Lansing Heritage folks in Australia, I got a JBL/UREI active crossover. I'll feed that from my receiver's preamp out, and divide the audio band into Low Frequency and mid/hi range.

I got an old Crown D75 amp (75w/ch) to feed the left and right mid/hi drivers, then found an old Harmon kardon Citation 22 to feed the woofers. This is a heavy monster, over 60 lbs (!), and its still on the way here, but it puts out 200w/channel. Not that I need to run the system that loud, but with nearly double the power to the woofers, it means nice crisp signal shapes for things like drum beats and other sounds with a sharp attack.

I'll post more when I'm further along ...

Posted by Heather at 6:00 PM | Permalink | Comments (0)

I've been way busy in the other world ... I just haven't been updating this site regularly!

Work has been busy -

Summertime always means lots of yard work.

Our friend Janet is now Reverend Janet Avery!

Last weekend we attended Roanoke Pride

Emma has been getting ready to start a new Church plant in Harrisonburg...

And I've been building the website for her ... http://www.mccshenval.com/

Posted by Heather at 7:23 PM | Permalink | Comments (0)

As usual, click the image to see a doublesize version.

Posted by Heather at 8:00 PM | Permalink | Comments (0)

As usual, click the image to see a doublesize version.

I always loved the style of MCC DC - such a wonderfully open space, full of light, and with that huge tree behind the altar and cross ...

We had been invited to the ordination service for our friend Janet Avery, what a great day it was.!

Posted by Heather at 9:20 PM | Permalink | Comments (0)