Sony SS-Cbx77 mini system speaker teardown.

[John3655]

Sony must have sold loads of these 25wpc dab/ipod mini systems back in the 2000's. Thought I would take a look inside the speakers. There are loads of these speakers on eBay for around £20.

The only way into the speakers, is to lever off the glued grill frame with brute force. It's broken the chipboard around the posts but cleanup the posts and it slots back together ok. 6 points of attachment, the mounting posts go straight through the front baffle into the interior, so the grills kinda have to be glued or otherwise sealed.


The crossover is one 1.8uf 100v np electrolytic in the path to the tweeter to filter out the low frequencies. The capacitor and all the wires are covered in foam. I guess a rattle might cause a return.



Amazingly for such a cheap speaker, the drivers have bucking magnets to increase field strength. The woofers are roughly 3" or 8cm in diameter.


The cabinet is ported but just glued chipboard with no filling at all. There is one glued in chipboard side brace.

What to do, is it even worth it. Well I had some offcuts of dodomat so I've stuck that inside. It sounds a bit less hollow now. I could add more braces to the corners.

Tacked a 150nf Panasonic ecwf capacitor to the electrolytic capacitors.


Hooked up to the main system they sound good, they won't be replacing my main speakers but might get a tour of duty somewhere.

 

[tgmartin]

I was under the impression that the extra magnets were oriented to cut down on the magnetic field induced outside the speaker cabinet that would cause CRT interference in old style TV sets, NOT for increased flux in the voice coil gap. The picture would get wonky if stray magnetic fields came close to the Cathode Ray Tube. Am I wrong?

 

[John3655]

I was under the impression that the extra magnets were oriented to cut down on the magnetic field induced outside the speaker cabinet that would cause CRT interference in old style TV sets, NOT for increased flux in the voice coil gap. The picture would get wonky if stray magnetic fields came close to the Cathode Ray Tube. Am I wrong?

Good question, well it's not a shielding cup, whether the magnet is increasing the field strength or opposing it I couldn't be sure. Just checked the Sony spec sheet, it says the speakers are not magnetically shielded so I can only guess they are for field strength.

 

[John3655]

Added a handful of loft insulation stuck in with silicone sealant.
Wasn't entirely happy with the gap around the front baffle, it seems fairly tight but there's at least a few mm gap in the groove the baffle sits in and no visible sealant, so went around it with slightly watered down PVA. Better.

 

[QuadDamage]

Those drivers are made by Eastech, by the way.

 

[John3655]

Those drivers are made by Eastech, by the way.

Thanks for that, think I've found the woofer

FSI521535-3806

This is a 3.5 inch 8 ohm driver, it is a Woofer features 0.8 inch voice coil with PESVW. In term of suspension system, cone is consisted by Paper Cone body with NBR surround and spider is consisted by NC. In term of magnet motor system, magnet is consisted by Ferrite material. It can be used on...

www.eastech.com

 

[QuadDamage]

Yep, the make drivers for Sony, Philips and JVC. Mostly OEM for mini hi-fi/home theater systems. Got some tweeters, midrange and woofers here.

 

[John3655]

The results above were good but got to thinking these speakers would be an ideal test bed for the latest full range drivers which are rumoured to be good. Slight risk here of appearing in the 'Speakers with questionable upgrades' thread!

Ordered these 3.5 inch Dayton PS95 full range drivers, they have a frequency response from 110hz to 17khz ~£25 each. Hoping they go lower when mounted up in a cabinet. The main selling point is no crossover, no capacitors, no PCB, no steel leads, no phase issues, all that complexity gone, and a clean point source. These have many glowing reviews, people using them in cars, on their own with subs etc.

I was a bit put out when they arrived as they are smaller than expected, turns out 3.5 inches is from mounting hole to mounting hole, the actual diameter of the cone including surround is more like 2.5".



I had hoped to just slot them in and get away with no woodwork but they only just sat in the existing holes without falling through, so I had to extend the mounting points inwards with blocks of wood, glued and screwed.

Pictured before fixing the drivers, the tweeter hole blocked up just needs blacking out so it doesn't show behind the grill.


The initial spectroid, a few minutes in, showing some response down to 70hz, red plot is the max, yellow ignore it's just what's playing. I might update this later if they run in.
They sound a bit thin but the midrange is really good. High volume levels from such a small driver too and some never heard before very low level details.


There is another model same size, more expensive, but with an aluminium cone, and a lower bass response.

6 hours in they loosened up, became louder and the small diaphragm was showing some high excursions. There is some bass but it's fairly quiet. Overall I would recommend them if it weren't for the fact they are not 3.5 inch drivers. Are they trying to say they're the equivalent of a 3.5inch, I don't know but that would open a whole new world of small cones being passed off as bigger. Maybe I've got it wrong, they are amazing just beware.