Monday, 25 September 2017

JBL Control 5 Restoration Project #2 - Part 4: Crossover Repair

Due to the age of these speakers, the original 4.7uF electrolytic capacitor had dried out. This resulted in a very quiet tweeter throughout all the 3 speakers. Brand new capacitors are on order to be fitted into the crossovers.
I installed the new crossover capacitors on the 30th of September. This did fully resolve the tweeter issue and the two tweeters are now working perfectly.
10x Polyester Film Capacitor-Various Values-100v,250v,400v,630v- 1st CLASS POST25x Electrolytic Capacitor (1uF 2.2uF 4.7uF 10uF 22uF 47uF 100uF 220uF 470uF)

Saturday, 23 September 2017

JBL Control 5 Restoration Project #2 - Part 3: Tweeter Magnet Repair

During transit, the tweeter magnet of the blown tweeter came away from the front metal and plastic attachment where the diaphragm glues onto. This is very difficult to align due to the VERY strong magnet.
You can get around this by inserting strong cardboard shims, letting the glue set for around an hour and them removing them. I used super glue to bond the 2 metals back together.

Friday, 22 September 2017

JBL Control 5 Restoration Project #2 - Part 2: Cleaning up old materials and preparation for new parts

I began the long laborious task today of taking these to bits, cleaning up the old woofer foam, cleaning the cabinets, and then diagnosing any possible issues.
A comprehensive list of the faults are:

  • All 3 woofers suffer foam rot
  • All 3 crossovers are defective in the sense they output a quiet signal to the tweeter, which can only really be due to dried out worn out capacitors. which new ones are ordered to replace them
  • One tweeter is severely damaged. The magnet was loose in the box as it had became detatched from the blown diaphragm. Getting this aligned again will be a huge pain but hey.
  • There are some holes drilled into the cabinets. This must be filled in with clear filler then painted black as otherwise you will experience air leaks which will really make them sound like junk.
On the whole, the condition is good. The cabinets look good and there is only one blown speaker in the equation, none of which thankfully are the woofers which happen to be the most expensive to replace. The grilles and the logo badges are amongst the best condition though out of the whole cabinet.
Please see the pictures I have attached to this post, from when I first unpacked them and took the grilles off, to them being fully apart and ready for parts.
The stages of repair will be: Cabinet repair, woofer refoam, crossover board recap, tweeter new diaphragm and line up the magnet repair.

Monday, 11 September 2017

JBL Control 5 Restoration Project #2 - Part 1: Ordered in

I have gone for something a bit different this time, I have managed to get hold of 3x JBL Control 5 speakers in immaculate condition. These have been imported from Spain, and have been a total investment of £103. The problem with them is, is that 2 have possible blown tweeters, and all suffer from foam rot. These will all be restored to full original working order. Despite the heavy price tag I paid, new tweeter diaphragms are only £15 a pair, likewise the foam surround kits per pair, and the total project will cost under £150. To get 3 new ones, the equivalent of a mint condition restored pair, you are looking at £600, so it is totally feasible and a good project at the very least. As soon as they come in I will add photos of them.

Homemade Subwoofer Restoration Project

A few weeks ago I was at a family members house and was offered this active subwoofer for free as it was about to go to the dump otherwise. Realistically I should have said no, it had a lot of problems, I have to work to a busy scheduele, so to me a 50 watt active subwoofer isn't worth saving from the trash. Anyway, this thing has an interesting story behind it. It was originally a Yamaha SW-P40 subwoofer, but it was taken to bits and only the subwoofer plate amp and volume/crossover control board was kept. A new cabinet was built, using thick MDF. The speaker driver was also replaced with a Sony 12" Xplod Car Audio subwoofer, yeah, totally not my cup of tea but that's what the previous owner decided to do. To make it worse, they painted it poo brown, and this was not the last of the problems. The cabinet, although very well built, rattled as the top plate had a thinner piece of MDF, the port tube was far too small so it caused a lot of port noise and didn't really help the subwoofer, it had a hole the top so was a nightmare for air leaks, and the thing rattled as the top plate like I said was thin. I had a free weekend last week and was pretty bored, so I decided to take a look at it. I began by removing the front driver, and began to tackle the air leak problem. I filled in the top hole with standard wall filler, which did the trick, and then decided to do something about it's lack of dampening material, which will have contributed to the fact that the cabinet resonated and rattled on the top plate. I took the insides of an old duvet and used a staple gun to cover each side of the cabinet internally, being sure to add extra material onto the top for good measure. Now this was done, the subwoofer was technically working fine, albeit with a stupidly oversized driver that so isn't designed for any kind of home audio application. I decided to paint it anyway, I sanded the "poo brown" cabinet down slightly, and then wiped off the dust with a damp cloth. The colour I chose was grey, as grey is not only an appropriate colour, but I happened to have a lot of it left over after decorating a room. I carefully began to paint the cabinet, saving painting the front fascia until last. I utilised a hair dryer to help set each coat of paint dry, the thing in total took 2 coats of paint to get a high quality and good looking finish. So this item has been saved from the trash, and instead, restored and then put on a local Facebook selling page for £35 under an all offers considered arrangement. At the end of the day, this is not a high quality piece of equipment, it looks good, has a big driver and goes loud, but it's not audiophile or high quality, unlike what I am used to. It is a good piece of kit for house parties because lets say if it blows up, your not going to cry about it, especially for the price I listed it for. But yeah, that's another piece of electrical equipment saved from the trash, and it should find itself a new home soon.

Saturday, 2 September 2017

JBL Control 5 Restoration Project

For many years, I wanted to own a pair of the JBL Control 5 speakers. I heard them in numerous commercial settings, including both Sheffield HMV branches (Meadowhall and High Street). These speakers to me have a certain look that somehow screams quality and pro audio. And what's more, the tone of the Control 5s have the JBL signature tone written all over it. Some might not understand what I mean by this, but basically all JBL Control series speakers have a certain midrange sound that is very distinctive. It is a strong, warm, midrange sound, that all the Control series speakers possess. But yeah, I scored my pair of these on eBay for a total of £153. I ran them for a short while on my 1989 Sony TA-V701 50W per channel amp, which naturally has a beautiful warm sound and was one of the high quality Japanese made units. Although I did not intend to use these Control 5s with this amp, instead I wanted to use them with my 5.1 home cinema amplifier as front speakers. So I did connect them to this (the Sony STR-DB780) and I set the impedance switch on the rear to 4 ohms so that the amp would not be overloaded by the 4 ohm impedance of the Control 5s. However, the next day, I was playing some music, and the foam surrounds went! At first I thought it was a blown driver, but I was very wrong. A few days later I managed to find a way to prise the grille off (yeah with a pizza scraper haha), and I discovered a small crack in the foam. I did a further inspection and noticed the actual foam surround was not even connected to the cone anymore, hence the violent rattling sound when the bass kicked in which lead me to believe at first I blew the speaker. So that was that, 2 days later I played Kingdom Of Rust by Doves rather loudly through the working Control 5, and then in no time the foam went on that. The solution was a refoam kit I had to import from Australia from a company called Queensland Speaker Repairs. I installed the refoam kit and they were as good as new, and the kit happened to cost £25. I made PayPal pay for this through a dispute though, as £150 or so is the top end value for a pair of fully working Control 5s with lots of life left in them, so I said the item was not as described and not tested properly (which was the case, if the seller had tested these properly the foam would have went on him also), and I managed to get the cost of the foam surrounds paid for. To this day, they sound incredible on my surround setup. And these are RARE speakers, they are no longer produced. They are available to buy, but for around £300-£600 A PAIR because they are no longer made. These prices are extortionate. JBL has actually now discontinued the old Control Contractor Series, and the Control 5 a while ago, so these speakers restored will have a very high value, although I definitely have no intention of selling them, I love these speakers, and once you hear the sound of them, it will become clear why I like them so much.

Wharfedale Diamond 6R Upgrade Project

These Wharfedale Diamond 6R speakers were manufactured in 1995. These at the time were a budget speaker for around the £200/pair price ran...