I have been using my sony ss-mb250h two way bookshelf loudspeakers for about two and a half years. Although i got them for a really low amount of money (eur 60) i was pleased with their sound quality, clean mids and highs, low frequency is not groundshaking but fast and accurate. They accompanied my fisher ca2221 and pioneer vsx-609rds during the last two years.
A few weeks ago, i finished my jfet buffered gainclone with kind help of the forum member 'dxvideo' and after that i realized what these cheap sony bookshelfs capable of... Since i bought them, they have been used for home cinema and daily music listening so i was not expecting miracles from these babies, but with the gc, they began to sound amazing and i decided to do some modifications with the box and wiring.
When i removed the drivers, i was disappointed with the wiring and crossover network, both of the driver cables were 0,5mm² ordinary copper wires connected with standard connection sockets inside and a "elytone" brand (probably china made) 1,8uf non-polar electrolylitic capacitor. On the other hand, thickness of walls and general workmanship is better than many more expensive cabinets around.
First of all i removed what's inside the cabinets, drivers, socket and the synthetic wool. There was only one piece of wool inside, placed on tha backside, but not attached to anywhere. I decided to cover all the walls with wool and attach them so they could not cause any nasty problems. With ordinary wood glue, i placed the old piece wool on its original location and covered all the other walls with a thinner fibre wool because i didn't want to reduce the volume of the boxes. After glueing, i let them dry for about 3 hours.
After the internal wool covering, i've been detailing on the wiring. The midbass cable i used is 1,5mm² oxygen free copper and 0,75mm² for the high frequency driver, again ofc.
The high-pass capacitor was a cheap electrolytic as i mentioned above. I used an EVOX PMR series (metallized polypropylene) capacitor in that position and increased the value from 1,8uF to 2,7 uF because i wanted a better high-mid frequency response. because the evox cap is bigger and heavier than the elytone, i glued it inside the box and on the front wall of the cabinet.
Instead of ordinary sockets that sony used, i soldered the wires to the terminals with a remarkable amount of solder for the best conductivity. After finishing the connections, i insulated all of them with electrical tape, twisted and fixed them together with plastic handcuffs. To reduce the resonance transition between the box and the surface beneath, i put tiny rubber pads under the cabinets.
After that i mounted everything back and now they are ready to rock!!!
First impressions; much better soundstage, tighter, deeper and more accurate bass response, more natural overall sound, high frequencies came up life-real, cymbals, china crashes are amazing. Vocals are realistic.
The total cost of these tweaks was about eur 7, but i can gladly say that the overall performance is doubled, great sound for a pair of eur 60+7 bookshelf speaker set.
Here are some photos:
A few weeks ago, i finished my jfet buffered gainclone with kind help of the forum member 'dxvideo' and after that i realized what these cheap sony bookshelfs capable of... Since i bought them, they have been used for home cinema and daily music listening so i was not expecting miracles from these babies, but with the gc, they began to sound amazing and i decided to do some modifications with the box and wiring.
When i removed the drivers, i was disappointed with the wiring and crossover network, both of the driver cables were 0,5mm² ordinary copper wires connected with standard connection sockets inside and a "elytone" brand (probably china made) 1,8uf non-polar electrolylitic capacitor. On the other hand, thickness of walls and general workmanship is better than many more expensive cabinets around.
First of all i removed what's inside the cabinets, drivers, socket and the synthetic wool. There was only one piece of wool inside, placed on tha backside, but not attached to anywhere. I decided to cover all the walls with wool and attach them so they could not cause any nasty problems. With ordinary wood glue, i placed the old piece wool on its original location and covered all the other walls with a thinner fibre wool because i didn't want to reduce the volume of the boxes. After glueing, i let them dry for about 3 hours.
After the internal wool covering, i've been detailing on the wiring. The midbass cable i used is 1,5mm² oxygen free copper and 0,75mm² for the high frequency driver, again ofc.
The high-pass capacitor was a cheap electrolytic as i mentioned above. I used an EVOX PMR series (metallized polypropylene) capacitor in that position and increased the value from 1,8uF to 2,7 uF because i wanted a better high-mid frequency response. because the evox cap is bigger and heavier than the elytone, i glued it inside the box and on the front wall of the cabinet.
Instead of ordinary sockets that sony used, i soldered the wires to the terminals with a remarkable amount of solder for the best conductivity. After finishing the connections, i insulated all of them with electrical tape, twisted and fixed them together with plastic handcuffs. To reduce the resonance transition between the box and the surface beneath, i put tiny rubber pads under the cabinets.
After that i mounted everything back and now they are ready to rock!!!
First impressions; much better soundstage, tighter, deeper and more accurate bass response, more natural overall sound, high frequencies came up life-real, cymbals, china crashes are amazing. Vocals are realistic.
The total cost of these tweaks was about eur 7, but i can gladly say that the overall performance is doubled, great sound for a pair of eur 60+7 bookshelf speaker set.
Here are some photos:
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http://www.diyaudio.com/forums/showthread.php?t=152582
http://www.diyaudio.com/forums/showthread.php?t=152582
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