Old Speakers New Sound
| by Mehul Mepani
Many of us own an old pair of loudspeakers that we have fallen in love with over a long acquaintance. Well, the fact is that they degrade over time. We do not realise it because the degradation is very gradual and spans across, at times, a decade.
Catch the culprit: Before you blame it all on that poor pair of loudspeakers; try different amps and sources. The culprit could be something else than the old wooden boxes!
Cables: Check them, they could have significantly got oxidised. There could be stark improvements in the highs with their replacement. If your old cables are expensive and you do not want to play poker by spending a fortune and finally discovering that the old cable was not so bad then there are ways. Some retailers would merrily lend finished pair of cables for audition with some deposit. Else go to the local electrical shop and try good fresh high quality electrical cable (insist that it is out of the box and not turned and twisted multiple times before handing over to you). If there is improvement here, then it is definitely worth investing into a dedicated speaker cable.
Internal Cables: If you have little bit of engineering skills then try changing the internal cabling too. This will involvehigh-wattage soldering so, ensure that you have good quality soldering material and required tools. Especially be careful with the soldering of the tweeters, as very thick cables and long heating can damage them.
Turn the drivers upside down: Your heavy drivers have been battling the force of gravity for many years now. There is a high chance that they may have succumbed to it a little bit. Turning the drivers upside-down reverses these ill-effects. Just like the damage has been gradual, even the improvement will be gradual. This will be effective for the woofers and mid drivers only. Drilling fresh holes into the cabinet and super-fastening your drivers will improve the performance further.
Connectors: Even the gold plated connectors can get oxidised over a long time span. Try some contact cleaner fluid and moderately abrasive cleaning of the speaker mounted terminals and the cable terminals. It is good to cut down about 10-15cm of the speaker cables at both ends and re-solder them with the (cleaned) old terminals.
Internal Connectors: There could be cold joints (crimped snap-type or pull-up type connectors) on the crossover circuit board. Pull them out and spray the contact cleaner and insert them a few times for self-cleaning. If they have lost tension then (very) carefully pressing them slightly with a flat-nose plier will improve not only the cleaning but also the overall contact. If you know what you are doing, then try soldering these joints with newer cables.
Change the tweeters: Most of the manufacturers use drivers from the OEM manufacturers. There are a few well known like the Seas, Scan-Speak, and Vifa, Focal etc. to name just a few. It is high chance that if you type the product code printed behind your tweeter then you will sniff your way through to these or any other manufacturer who actually made the driver and is still in production. There are websites who sell these in smaller quantities. This could be a big improvement as far as the tweeters are concerned.
Many speaker drivers are ferro-fluid cooled and I have seen many of them where the fluid has leaked out. Replenishing the fluid and plugging the leakage will keep the coils cooler and sufficiently damped to regain the older performance levels – especially during long listening sessions. This is an advanced mode; see that you have expert help or sufficient engineering skills to carry out this mod. Do not try this if you loudspeaker is natively air-cooled.
Crossover: Again an advanced mode but an important one. Inspect the crossover circuit and see if the capacitors are damaged, leaked or aged. Do not remove them unnecessarily till you have the exact replacement in your hand. Avoid equivalent parts; insist on the same part replacement unless the circumstances are exceptional and amounting to repair rather than mod. However, heating all the joints on the board with a tad addition of the fresh soldering metal will help a great deal.