Because I can. When these KLH Model 17 speakers re-arrived in my possession I kept getting the idea to experiment with changing the drivers out.
I had scored a set of Philips AD7060 4 ohm fullrange 6 inch drivers from a thrift store a few years back and was waiting to find a home for them. I had heard great things about the Philips full range drivers and sold a similar pair of alnico versions on Ebay for a great price a while ago.
I have hooked the AD7060 to the tube amp and was impressed by the clarity and efficiency of these little 6 inch wonders, I just knew they where shy on the bass without a super large cabinet, this is where the Model 17's come in.
The Model 17's have a great tight bass from an acoustic suspension cabinet along with a fairly efficient 10" woofer that goes well into 40hz.
I opted to gut the crossover and remover the Model 17 tweeters and enlarge the hole to accommodate the AD7060 fullrange driver. I also opted not to use a crossover between the drivers as the KLH has a natural roll off around 1500hz and is a bit less efficient that the Philips. The AD7060 does not really shine until around 150-200HZ and is pretty smooth to 15,000HZ, about where the original KLH tweeter ran out of steam.
I love matching fullrange speakers with single ended tube amps, this is audio nirvana to me, you get to hear all the music.
The changing of the tweeter to a fullrange Philips has made these speakers shine, completely opened up the sound stage, words can not convey the difference this change has made.
I know this would seem unconventional to most but I love the sound from this set up. I have been running off the four watt tube amp and wow! the sound is all there and loud enough.
