Heather's Blogpile

My upstairs speakers are based on a mid-70s pair of JBL L200 speakers. I loved the look of the cabinets, but the sound was a bit limited. So I added 2405 slot super-tweeters and built new crossovers to make them 3 ways. A few months back I bought a pair of JBL 2397 Smith horns - they are mid-range horns, made of grey painted MDF, and designed for a 2 inch compression driver, tho I'm using them with a pair of adapters and my (cheaper) 1 inch drivers. They replace the "round" horns that are in the cabinets, hidden behind the textured foam grill. They sounded very nice but the grey industrial paint was UGLY. So, I found an audio friend who offered to make me a pair in nice wood, and I chose walnut, to match the JBL L200 Cabinets they sit on. They look great and sound WONDERFUL!

Posted by Heather at 7:45 AM | Permalink | Comments (0)

I had been shopping for a better quality active crossover for a while, and a week ago, I won an Ashly XR1001 on ebay - and yesterday it arrived. took a while to swap cables around but once I power it on - well, it really was like a veil had lifted off the music!

Just click the image to see a larger size version.

Posted by Heather at 6:23 PM | Permalink | Comments (0)

Just click the image to see a larger size version.

Well, I still haven't built grills for them, but I've got a JBL active crossover and a pair of amps to feed them, so the woofers are very tightly controlled, standup bass sounds like it should, and the rest of the frequencies - quite nice! I need to toe them in a bit, and we really should have them further from the sidewalls, but - its what we have right now, so I guess I'll suffer as best I can ...

Posted by Heather at 10:01 PM | Permalink | Comments (0)

Ever since I got those old JBL 4320 Studio Monitors in Philly for $300 for my birthday last year, I'd added parts and collected bits and done a series of upgrades from the original 2 way design with horns, to a pair of DIY JBL 3-way studio monitors, and finally into DIY 4-way monitors. I'd found a schematic for a model 4333 (passive) crossover network, built that, and had gotten a nice improvement from all that. I even got an electronic crossover, dual amps and biAmped them. But, it was still a kind of hack.

Continue reading "More big big JBL fun ..." »

Posted by Heather at 9:39 PM | Permalink | Comments (0)

We have these wonderful speakers at the left and right front of the TV room, but I only have a simple JBL EC25 speaker doing center channel dialog duty. Its a nice enough 2-way design - a titanium tweeter and a pair of 5 inch woofers in a very nice beech finish cabinet - and it matches the shelf system very well.

Continue reading "Rethinking the center" »

Posted by Heather at 9:12 PM | Permalink | Comments (0)

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.

Continue reading "biAmpin' the monsters" »

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

Our JBL Control Monitors in their new home on top of the media shelves!

I built the crossovers last week and they sounded great. Satruday was a rainy day so I opened the cabinets up by pulling the3 15 woofer. Once open I mounted the crossover to the inside of the cabinet, wired the 3 drivers to the network using thick copper zipcord, then after a few tests, Emma and I cleared the tops of the shelves and lifted these 100+ lb monsters onto the shelves.

We lost a bit of Bass, compared to their previous position on the floor in front of the shelves, but they do sound nice and we have our floor back again!!!

Posted by Heather at 3:17 PM | Permalink | Comments (0)

Picture of our JBL Control Monitors on the Media room floor, with Dolly on the back of the futon!

The end result - my homebuilt grills & JBL Blue cloth - Rich!

The speakers are ancient (circa 1969-72) and many parts are NLA - No Longer Available. That just means I can improve them while I restore them. One thing I have already done is to add the slot tweeter to extend the high frequency range.

Another goal I have while working on these old speakers is to make them look better and fit our home's style. Thats a tough goal with big dark walnut boxes that are just under 2'x2'x3'. One reason I got them so cheap is because the grills were lost/damaged years ago - exposed speaker faces may excite my inner-geek, but functionally, there's no reason not to cover them up. But again, these are long out of production - so - If I want grills, I'll have to build them myself.

Continue reading "JBL 4320 project continues" »

Posted by Heather at 6:07 AM | Permalink | Comments (0)