JBL Control 5
I bought a pair of these JBL Control 5 between 1989-1990. At that time, I was producing audio-visual shows and I needed a pair of speakers for Voice Over monitoring and Soundtrack mixing. I can still remember I was quite disappointed at them, considering they were JBLs. They don’t seem to be as clear as I expected.
These Control 5s have been haunting me ever since. Now, almost 30 years later, I decided to find out why I disliked the Control 5 that much. I managed to buy a pair on eBay for a reasonable price. As I expected, the speakers arrived with both woofer surrounds rotted. Yes, there’s sound, as described, therefore listed as working. Buyers beware. Just because there’s sound doesn’t mean the speakers are good.
I bought some new surrounds and duly went about with the messy process of refoaming. The worse part is scrapping off all the old glue on the woofer frame. I don’t know what kind of glue JBL used but it looks like contact cement to me. Eventually, both woofers have new foam surrounds which I hope will last longer than the originals.
Control 5 Woofer Thiele & Small
With the surrounds in place, I extracted the T/S parameters with my DATS. It brought up some surprises. The woofer has a nominal impedance of 4Ω, an Fs of about 70Hz and a Qts of 0.59. Vas is about 18 liters. The second woofer measured almost the same. We can take it that they are matched and their voice coils are not damaged.
Control 5 Titanium Tweeter Thiele & Small
The Control 5 titanium tweeter was measured with a nominal impedance of 8Ω. Nothing out of the ordinary there. What is surprising is that it has an Fs of 2,163Hz. That is unusually high for a 1 inch tweeter.
Part 1 – Thiele & Small Parameters
February 12, 2020Projects