Although this post is DIY-orientated, I hope that the mods won't mind keeping it here, as I think it might be of interest to all.
In my experience, the main cause of failure of dead subwoofers is a blown plate amp. 90% of the blown plate amps I have seen are not repairable or - to be clear - not economically repairable. An alternative to repair is obviously to replace the whole plate amp, but these are not really available in our market, unless you import, which does incur further costs. It is also quite rare that products' distributors are able to provide assistance, especially for discontinued models (I'd be happy to be proven wrong on this one).
One viable option to restoration is to replace the plate amp's function with an external amplifier. That is, to bypass the plate amp and to feed the driver directly from the external amp. If done this way, one should be aware that whatever features were built into the original plate amp will be lost. Apart from the user adjustable controls, such as low-pass crossover frequency and level adjustment, there are two features that the user may not be aware of that might be included into the design of the plate amp:
1. Sealed subwoofers, especially those with small enclosures, may contain low-frequency boost equalisation.
2. High-pass filtering to protect the driver and limit power demands on the amplifier.
Point (1.) is something that may result in my proposed fix being not equivalent in performance, but it's worth a try.
To Illustrate:
My own DIY sub uses an Adire Audio Shiva 12" driver that has two voice coils. I was able to use two channels of my Rotel RB-985 AV amplifier to drive them each, respectively. Normal subs would need only one amplifier channel. I used my AV processor to manage crossover between my main speakers and the subwoofer (mains set to "small", crossover 80Hz).Connection is as per usual; use the subwoofer line out to drive the new dedicated subwoofer amplifer and connect the amplifier's speaker output to the subwoofer driver. Ensure that the enclosure air seal is restored after implementing the connection.
AV processors and receivers typically have bass management on board, especially newer models. I have not yet appied equalisation, but my current setup is a leap forward from what I had been using the past few years, due to extended low frequency and relieving my main speakers from low bass duty. My "surround" experience is currently limited to 3.1, but it is no great loss, as I listen to stereo, mostly.
In my experience, the main cause of failure of dead subwoofers is a blown plate amp. 90% of the blown plate amps I have seen are not repairable or - to be clear - not economically repairable. An alternative to repair is obviously to replace the whole plate amp, but these are not really available in our market, unless you import, which does incur further costs. It is also quite rare that products' distributors are able to provide assistance, especially for discontinued models (I'd be happy to be proven wrong on this one).
One viable option to restoration is to replace the plate amp's function with an external amplifier. That is, to bypass the plate amp and to feed the driver directly from the external amp. If done this way, one should be aware that whatever features were built into the original plate amp will be lost. Apart from the user adjustable controls, such as low-pass crossover frequency and level adjustment, there are two features that the user may not be aware of that might be included into the design of the plate amp:
1. Sealed subwoofers, especially those with small enclosures, may contain low-frequency boost equalisation.
2. High-pass filtering to protect the driver and limit power demands on the amplifier.
Point (1.) is something that may result in my proposed fix being not equivalent in performance, but it's worth a try.
To Illustrate:
My own DIY sub uses an Adire Audio Shiva 12" driver that has two voice coils. I was able to use two channels of my Rotel RB-985 AV amplifier to drive them each, respectively. Normal subs would need only one amplifier channel. I used my AV processor to manage crossover between my main speakers and the subwoofer (mains set to "small", crossover 80Hz).Connection is as per usual; use the subwoofer line out to drive the new dedicated subwoofer amplifer and connect the amplifier's speaker output to the subwoofer driver. Ensure that the enclosure air seal is restored after implementing the connection.
AV processors and receivers typically have bass management on board, especially newer models. I have not yet appied equalisation, but my current setup is a leap forward from what I had been using the past few years, due to extended low frequency and relieving my main speakers from low bass duty. My "surround" experience is currently limited to 3.1, but it is no great loss, as I listen to stereo, mostly.
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