Sony SS-NX1 Speaker disassembly - Late 90's audiophile mini system speakers

[Xmall]

Hi All,
I recently picked up a pair of Sony SS-NX1's from the local tip shop - was not able to find a lot of information online - so after some encouragement on another thread, thought I would post what i know from my tinkering

Photo of the speakers and my setup below:

(Noting there are plenty of mistakes with my setup - working to correct these )

I should acknowledge, that I know little about audio, so I may miss important details or get things wrong. I'll try and roll any feedback back into this main post in case others in future are looking for info. I've been getting some help with the basics on another thread: https://www.audiosciencereview.com/...cy-response-testing.56193/page-2#post-2051620 - but thought I'd start a separate thread for this info.

Background:
So I picked these up from a local tip-shop for a mortgage shattering $15 (AUD) ($9.87 USD at the time of writing) - thinking what have I got to lose.

Unfortunately 1 of the speakers had a swollen cap - which led to burn-out of one of the tweeters (See the Cross-Over section below). I replaced the capacitor - changed the tweeter with an 8 OHm (from a 6OHm) then balanced the high pass impedance with a series and parallel resistor to tune volume - and minimise impact on the cross-over point.

Probably the only important bit here, is I will have modified the response from one of the speakers - so will focus on the 'original' here for any measurements etc (unless people are interested in further details on the repair).

General system Info:
From what I have read, the these were sold in the 90's as part of an 'audiophile mini-system' - As an audio novice, I am going to assume it was targeted at Audiophiles who wanted a setup in other rooms that was... not truly awful to listen to?

Photo of the system below (Curtesy of facebook)

A manual for the system can be found here: https://www.manua.ls/sony/mhc-nx1/manual?p=7

Speaker Details:
Within the manual there was limited information on the speakers but I've snipped what was shown:

Starting with the tweeter - this is a 1" dome, though I cant comment on what type. The tweeter is fixed to the face plate and sits in an isolated cavity within the main speaker enclosure (more on that below). The speaker measures around 30mm deep by 55mm across:

Now, onto the woofer - this seems pretty hefty (coming from a pair of tiny satellites) measuring 170mm across the face plate, 80mm across the rear magnet and about 110mm deep (was hard to measure precisely).

Speaker Enclosure

The enclosure is a solid, but cheaply made particleboard box with a faux birch veneer. The faceplate is plastic, only 3-4mm thick outside of the borders - but has reasonable stiffness. There is minimal bracing inside the enclosure, consisting of MDF wedges glued into all of the corners. The enclosure also includes a thin (maybe 10mm) piece of foam for damping, and I noted the tweeter sits inside an isolated cavity, to reduce impact from the woofers.

To the reflex bass port, this is front facing - approximately 100mm long (with the faceplate on) and appears to have some sort of divider at the internal end - the purpose of which... I'm unsure. The design includes a little rubber gasket which seals between the fixed portion of the bass port and the faceplate.

Cross-Over Details:

Now to the fun bit. After disconnecting everything, I traced out the circuit diagram by looking at component ends and figuring out which were connected.

The crossover screws into the back of the speaker and is mounted on a standoff on a custom made circuit board.

The following components were noted:

1x 3.3uF 50V electrolyte capacitor. This was swollen on one of the speakers, and I believe it led to burning out one of my tweeters.
2x 12uF 50V electrolyte capacitors.
2x Fairly large air core (or plastic core?) inductors. These appear to be custom wound, as they both use the same base - but appear to have a different number of windings.

(The long axis of the circuit board is 80mm for reference)

The swollen capacitor in the photos above was replaced with another electrolyte cap - about 1/5 the size but based on a quick google apparently cap sizes have decreased substantially in modern electronics.

From what I can make out, and the resources I found online I'll take a stab in the dark and say it looks like this is running a Butterworth 2-nd order low pass and 3-rd order high pass?

Circuit diagram below:

As I had to replace the tweeter on one of the speakers, I also had to add a series and parallel resistor to the tweeter (I.e. resistor (about 3Ohm from memory) between the 12uF cap and the tweeter in the second diagram, then a second (I want to say 18Ohm, but i cant find my calcs!) from between the 12uF capacitor and the tweet to ground.

I can upload the modified circuit if anyone is interested. This DOES appear to have impacted the sound (and not in a good way) - but I think I've managed to correct most of it through EQ on the amplifier.

Agricultural Response Curve testing:
Please let me preface this section by saying I KNOW LITTLE ABOUT AUDIO - I'm a newbie with a cheap, calibrated USB-Mic that plugs into a smartphone so please take these readings with maybe a tablespoon of salt (a grain may not cut it!)….

Setup was to empty the room, move the speaker to the front of my coffee table on foam to try and eliminate some of the early reflection. Readings taken with a smartphone and calibrated Dayton IMM-6c on a boom stand. (Note my kids and they couch they are moving were out of the way when I did the readings

First reading: Was mic setup 550mm from the speaker - then testing in front of, and horizontally offset 200, 400 then 600 (So off axis(?) 20, 36 and 48 degrees):

I do have psychoacoustic smoothing on here - in an attempt to show the off-axis performance a bit clearer. Seems unusual that all plots converge about 3.5Khz (Possible a reflection issue here?)

SPL 40 - 95

Top trace (light blue): On Axis;
Second trace (darker purple): ~20 degrees
Third trace (darker blue): ~ 36 degrees
Fourth trace (Magenta): ~ 48 degrees

Second chart is the on-axis speaker response - 1/12 octave smoothing applied. Same empty room setup

I did notice a vibration issue somewhere between 200-300 hz - (think its the crossover mounting board) so I'll see if correcting that makes any difference to horrible peak at that point.

Last one is reproduced from the other general frequency testing thread linked above:

Green Trace: Full Setup, boom mic at listening position, furniture in place - Audyssey EQ Off (Sub crossover 100hz)
Purple Trace: Full Setup, boom mic at listening position, furniture in pace -Audyssey EQ ON (Sub crossover 60hz as set by Audyssey)

SPL Scale 40-90 dB

Wrap Up:
So that's all I have so far. All in all, I'm quite pleased with the sound as it stands. I don't have much experience with 'good' speakers so I cant really give an objective opinion - but I'm happy with where things stand.

Next steps will be making some stands for the speakers to get them off the TV cabinet, a few more tests to better understand reflections etc and room impacts (just for fun), then I want to have a crack at room tuning.

Please let me know thoughts, whether this sort of content is useful - and any tips of tricks for improving the speakers or the sound that anyone might know.

Cheers!
Xmall

 

[TonyJZX]

here's a random back pic off ebay or whatevs

https://imgur.com/a/CKgRbJj

sony put a lot of money in the front so it looks nice in your million dollar apartment but the back looks like a bombed out 3rd world slum

the wood like material looks like it would not last many tropical summers in Malaysia, where they are made, given they look very absorbant... hygroscopic is the word i would use

i think the front looks so 'contemporary' you could use it today

and the cones and crossover looks ok too

i dont doubt they sound donkey

 

[Keith_W]

Looking at the grain size of the enclosure, it looks more like particle board than MDF. Both are sawdust held together with glue, but particle board is less dense and it's cheaper.

I don't wish to rain on your parade. What we should be doing is helping you get the best sound with what you have, and not criticize the design of your loudspeaker and make you feel bad. What matters is whether you are pleased with what you hear.

 

[Ken Tajalli]

From the pictures of the xover, I can see a damaged capacitor!
the one with a domed top. replace that. It is only a 3.3uF, so use a film or plastic cap. Don't just stick an ordinary electrolytic. From the pictures of the cabinet it seems someone has done exactly that!
If you have a dip at around 4K, I am going to take a wild guess that the xover frequency is not right, as that region is a typical hand over frequency.
If after you replace that capacitor, you still have a dip, then the 12uF cap on the bass filter.
Well done and good luck.

 

[Xmall]

Looking at the grain size of the enclosure, it looks more like particle board than MDF.

Thanks Keith, you are correct. I had to google the difference but it does look more like particle board. I'll fix the main post on that point.

don't wish to rain on your parade. What we should be doing is helping you get the best sound with what you have, and not criticize the design of your loudspeaker and make you feel bad. What matters is whether you are pleased with what you hear.

No stress - the purpose of this post was simply to put some info on record that I would have found helpful, but couldn't locate. Quality is a relative metric, if these just end up being a stepping stone and getting into the audio side of things I wont be sad about that - I have to say the wharfedale diamond 12.1s look nice and are a pretty attractive price....

@TonyJZX funny you note the typical swelling behaviour - my set have clearly sat in a shed for awhile and are showing signs of moisture absorption (minor) at the joints - im in the Southern most state in Australia - very little humidity here but can still be a problem.

From the pictures of the xover, I can see a damaged capacitor!
the one with a domed top. replace that. It is only a 3.3uF, so use a film or plastic cap. Don't just stick an ordinary electrolytic. From the pictures of the cabinet it seems someone has done exactly that!

I'm going to have to confess Ken, that i used an old photo from before I swapped out he damaged capacitor... aaaaand I used a cheap electrolytic as that's all I could get from the local electronics store. (I've added some details to the main post - as i meant to add this and forgot).

The new cap is about 1/5 the size (same voltage and capacitance).

I should note however, that this cap change was accompanied by changing the burned out tweeter. Replaced the burned out 6OHm with an 8Ohm, and then had to balance with a couple of wire wound cement ceramic resistors so the rest of the cross over saw the same X-over point - so I think the cap issues probably pale in comparison to the havoc I've wreaked there

I should note, the caps and tweeter were on the 'other' speaker (not the one I took the measurements from - outside of the full setup (third graph) which was both plus sub.

If you have a dip at around 4K, I am going to take a wild guess that the xover frequency is not right, as that region is a typical hand over frequency.
If after you replace that capacitor, you still have a dip, then the 12uF cap on the bass filter.

That's an interesting point - would it be possible from the circuit diagrams and the info I have to take an educated stab at the X-Over frequency as designed?

I didn't notice any swelling in the larger caps - can these degrade without showing external symptoms? Of course if i'm going to start buying better components to swap out - the bigger question would be is it worth it - or should i be investing in a better set of modern speakers.

 

[DWPress]

I applaud your efforts to learn more about taking measurements (on your other thread) and saving these from the landfill. The frequency response really doesn't look that terrible but at this point you're probably better off investing in newer decent speakers to fill a room that size with good sound. With all the plastic bits I'm sure resonances and distortion kick in once you get over a certain SPL and reverse engineering the XO may or may not get you improved sound in the end.

Otherwise if you're going to open them again and continue - add some internal bracing, polyfil and maybe some butyl to the inside of the front facia.

I totally get it though - I use 3 of these in my house TV room. Nondescript 2way speakers from a Panasonic sa-dp1 bookshelf system that sound (and measure) really good up to about 80dB before they start falling apart.

 

[JaapD]

“aaaaand I used a cheap electrolytic”. I hope you at least used a BIPOLAR electrolytic capacitor. We are working with AC voltages here. Expect extremely short life in case of non-bipolar caps.

If it were me I would not hesitate to exchange the caps against non-electrolytic types, easily to be bought on-line.

Cheers!
JaapD.

 

[GXAlan]

What I like about speakers from that era are that they are relatively attractive looking. My recommendation would be to back the speaker up with some room and speaker EQ.

It looks like you have a center channel. What AVR are you using?

 

[Xmall]

I hope you at least used a BIPOLAR electrolytic capacitor.

Thanks JaapD - Yes i did get a Bi-Polar electrolyte cap I noticed the old one had NP stamped on it (non-polar) and managed to figure that bit out.

I had another look - and a place called Mouser Electronics seems to sell components for pretty good prices. When I looked initially I was seeing $10 per component (might have been a special order from the local place - cant recall now). But at a few dollars per component there's no harm in giving it a shot.

They seem to be selling a few different types:

I'm not quite sure what an aluminium organic polymer is...

@Ken Tajalli you mentioned film or plastic - would either of these fit the bill?


If I can get some cheap components I might swap them out just to see the difference

It looks like you have a center channel. What AVR are you using?

The AVR is pretty old, I think it was a mid-range product when i bought it. Denon AVR-1713.

I was using a set of Klipsch Quintet speakers for years - also have a sub that came with that (think its an 8 inch).

I'm still using the Klipsch centre and sub - just swapped out the front left and right for the Sony's - as the room was far to big for the tiny Klipsch satellites

 

[Lux_ury]

Super effort, another one saved from the skip. I've just done a Sony set 10 dollars to save her and she had original boxes from 1982. SS-E34.
clicky

 

[GXAlan]

Thanks JaapD - Yes i did get a Bi-Polar electrolyte cap I noticed the old one had NP stamped on it (non-polar) and managed to figure that bit out.

I had another look - and a place called Mouser Electronics seems to sell components for pretty good prices. When I looked initially I was seeing $10 per component (might have been a special order from the local place - cant recall now). But at a few dollars per component there's no harm in giving it a shot.

They seem to be selling a few different types:


View attachment 385905
I'm not quite sure what an aluminium organic polymer is...

View attachment 385906


@Ken Tajalli you mentioned film or plastic - would either of these fit the bill?


If I can get some cheap components I might swap them out just to see the difference



The AVR is pretty old, I think it was a mid-range product when i bought it. Denon AVR-1713.

I was using a set of Klipsch Quintet speakers for years - also have a sub that came with that (think its an 8 inch).

I'm still using the Klipsch centre and sub - just swapped out the front left and right for the Sony's - as the room was far to big for the tiny Klipsch satellites

In that case, moving to an Audyssey XT32 or Dirac enabled setup will likely give you years of enjoyment!

The value of ASR isn’t just to reward engineering hygiene or accomplishments but to also help people maximize the value of their existing setup and avoid chasing the “next upgrade.”

 

[Ken Tajalli]

Get a pair of plastic or film (anything but electrolythic) from ebay for peanuts.
People have old stock from tube amp days, they sell them for nothing.
OK they are a bit bigger physically, but they never blow up, so your amp and driver stay safe.
Change the other side too.

Vishay Roederstein Capacitor 3.3uF 100V 10% MKT 1822 MKT1822 | eBay

New by Vishay Roederstein. 26.5x18.5x10.5mm. Techno Star. Lead pitch: 22.5mm.

www.ebay.com

 

[Salt]

If I understand correctly you measured the unrepaired one.
Could you provide measurements of the repaired item?

 

[mhardy6647]

Gotta love the bucking magnets for shielding if they're used near a CRT.

 

[Ken Tajalli]

Gotta love the bucking magnets for shielding if they're used near a CRT.

good one!
not everybody is saavy that way to know.

 

[mhardy6647]

good one!
not everybody is saavy that way to know.

aww, shucks -- twarn't nothin'.
Marky blushes.

Using a bucking magnet was one of several ways to make loudspeakers with large-ish magnets amenable to close placement to a CRT. In seriousness, I mentioned it because a priori I'd think making these little loudspeakers "CRT-monitor friendly" results in un-necessary (from 2024's perspective) complication (e.g., of the crossover design). The net effect (as I recall) of adding the bucking magnets (at least typically) is to raise Qts of the driver. That doesn't necessarily mean the drivers are "worse" per se, but they're different than they would be with a single magnet.

As long as I am wasting forum bandwidth: Here's a cute (and surprisingly good-sounding) little Pioneer-made "fullrange" driver made for TV use that also used a bucking magnet.

 

[JaapD]

Get a pair of plastic or film (anything but electrolythic) from ebay for peanuts.
People have old stock from tube amp days, they sell them for nothing.
OK they are a bit bigger physically, but they never blow up, so your amp and driver stay safe.
Change the other side too.

https://www.ebay.com/itm/1220495813...LVlT4nvD2Lg6SsO+VLc3weSw==|tkp:Bk9SR46436KoZA

I confirm what Ken says "anything but electrolythic". Also, MKT's are very good and super reliable.

Cheers,
JaapD.

 

[Ken Tajalli]

Using a bucking magnet was one of several ways to make loudspeakers with large-ish magnets amenable to close placement to a CRT. In seriousness, I mentioned it because a priori I'd

Bucking = shielded
for our British members!

 

[JaapD]

.... for our British members still using CRT's

Cheers,
JaapD.

 

[Ken Tajalli]

.... for our Britisch members still using CRT's

Cheers,
JaapD.

In our defence, we can claim we have been Shielded.
Better than having been Buckered!