Was checking out an old pair of Goodmans Maxim 2 yesterday - they had been on my mom's stereo since about '87. Noticed v high dc resistance on one so took it apart expecting a loose connection. After removing the xo board attached to the bottom of the cab it became apparent that a 450mF cap was in series with the mid-bass! This has to be for dc protection surely, but I've never seen it before. The maxim2's were a hi-fi starter speaker with some pretension for sound quality - surely the negative of affecting the SQ outways the benefits of saving them from the small chance of an amp frying them? Any one else seen this in a commercial model?
If as you tell me the impedance of the spk is about 7ohm, this is a high pass filter with one real pole at 101.05 hz, so the speaker can receive those frequencies below with attenuation augmenting 6db each time the frequency goes down an octave. This apparently is wright.
Good luck !!!
Good luck !!!
Hi,
I presume you mean a 470uF capacitor. Yes it has been done before.
KEF used it a lot. Basically you add a series capacitor to a sealed
box with a Qbox of around 1. The capacitor reduces the peaking
somewhat, extends the bass a little and does give DC protection
and some subsonic protection also.
Nice little speakers, used them a nearfields on a desk in a studio.
Probably worth replacing the bipolar electrolytics, try
Falcon Acoustics | The Leading DIY Speaker Parts and Kit Supplier since 1972
Make up the 470uF with a 450uF bypassed with 20uF.
rgds, sreten.
http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Black Box_copy.pdf
I've also modelled it in the free demo version of Basta! and it does work.
I presume you mean a 470uF capacitor. Yes it has been done before.
KEF used it a lot. Basically you add a series capacitor to a sealed
box with a Qbox of around 1. The capacitor reduces the peaking
somewhat, extends the bass a little and does give DC protection
and some subsonic protection also.
An externally hosted image should be here but it was not working when we last tested it.
Nice little speakers, used them a nearfields on a desk in a studio.
Probably worth replacing the bipolar electrolytics, try
Falcon Acoustics | The Leading DIY Speaker Parts and Kit Supplier since 1972
Make up the 470uF with a 450uF bypassed with 20uF.
rgds, sreten.
http://www.humblehomemadehifi.com/download/Humble Homemade Hifi_Black Box_copy.pdf
I've also modelled it in the free demo version of Basta! and it does work.
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