Wednesday, November 14, 2018

Solid Monitor speakers and ceiling mount safety

DIY.

The Solid Monitor is a speaker manufactured early 90's, which makes them over 20 years old by now. They are (not that) small, solid monitor / bookshelf speakers, with decent high and mid and (for their size) quite acceptable bass.

These speakers are literally quite heavy, so you have to take some care when mounting these against the ceiling.


Atmos

I decided to set up an Atmos / Auro3D amp at home, which meant I needed ceiling mounted speakers. The ceiling downstairs is partially concrete, partially gypsum, so I could not use 'in-wall' (in-ceiling) speakers. (More about my setup and Atmos here.)

I typically don't like overly small speakers (they often sound too thin) and had been considering some JVC woodcone units when I spotted a (four piece) set of second hand Solid Monitor speakers on Marktplaats (Dutch equivalent of eBay). A little investigation on the Internet later I decided to pick them up. These weren't new (hey, 20 years!) and weren't in top condition, but still...

I actually like the sound of these small speakers, tonally they seem to match my 'vintage' (expensive word for 'old') Magnat Lambda's quite well. As one of the speakers had a damaged mount I looked for a second batch and ended up with 8 Solid Monitor speakers, all mechanically sound, drivers in good condition, with two of the eight mounts damaged but that was about it. Not a bad deal I think.

I actually got a Harman Kardon CD player and amplifier thrown in as well. Which I quickly passed along to a relative. 


Rock Solid

The Solid Monitor is also known as Rock Solid Monitor. They were designed by (the people of) B&W, and made in China and Taiwan. Originally a separate brand it seems everyone considers them a 'real' B&W product nowadays. Here's a product sheet comparing the different models.

They are actually surprisingly good. Some of the old reviews (the ones I could still find online) were very positive. The batch that I have (all 8) sound pretty good after 20-odd years. The Taiwan build units seem to have a tad better dampening and better finishing but nothing I could hear. (I only noticed this when opening them.)

There's another speaker, the S100, sometimes called the Solid Monitor S100, which is not the same thing. Then there's the Team model (never seen one in real life) and the HCM2 (sometimes called the S75).

The HCM2 / S75 isn't bad, but not as heavy duty. If you run a smaller amp they might be a good choice, and they do not require a stand so are a better pick when used as a bookshelf speaker.

There seems to have been a variant of the original Solid Sound Monitor with a different looking front and 'hidden' bass reflex port. (Drivers and backside seem to be identical.) I'm not convinced two triangles will sound better than a single round one, but with the fronts on these look better, yes. I've not found any 'official' data of that unit though. Is this perhaps the 'Team' version? Haven't got a clue.




Colors

The Solid Monitor came in different colors and color combinations. I've seen black ones, white ones, there may have been gray ones. Inserts in black, white, pink and green.


You might run into more colors on the Internet, but many are likely to be 'aftermarket paint jobs' 😄

The full white ones look best. Mine are all black. (Two have been white but a previous owner painted them black.)


Specs

From the original folder. Click to enlarge.


90 dB for 2.83V / 1W in 9 ohms, 75 Hz to 20 kHz +/- 3 dB, 150W max... That should do.

I guess the 75 Hz might be a bit of a stretch. Audyssey sets the cross over frequencies to 120 Hz, though I tried some bass test tones and without Audyssey I could definitely hear some bass below 100 Hz, not abyss deep but still enjoyable.

Then again, they are not that small 😏.


Mounting

Mounting speakers on a ceiling can be a problem. In this case, I wanted to create a hybrid Atmos / Auro3D setup, and four (actually five, but I get back to that) are located in places where people walk or sit below them. So it's a good idea to mount them properly, and make sure they won't drop on somebody's head.

When examining the mount you can see a single nut keeping the whole 'T' shaped mount together. This nut might get loose over time. Also the aluminum 'knob' may break (two of the eight speakers I obtained had that part broken).


In the past some kind of safety cable could be bought as an option. I tried to obtain more information about this option but could never find anything, so I had to cook up my own solution.


Inside

Unable to find a small steel cable or other solution, I decided to use a special kind of 'nylon' cord (sorry, I don't know the exact name of the material). I needed some way to fix this to the speaker as well as to the ceiling.

The casing material is a thick, sturdy kind of plastic but it isn't thick enough to hold screws directly, so after opening up the speakers I glued small wood blocks inside.




I then used a round head screw, driven from the outside into the wooden block on the inside, and attached the nylon cable, of course with some knots.

The cable loops over the horizontal part of the original ceiling / wall mount (there's a little space there right at the center of the 'T').


Now if, for whatever reason, the mount breaks or the nut gets loose, and subsequently the speaker would drop then it won't fall down all the way but will be stopped by the cable.

Or so I hope.

I did test though, just to make sure...


Safety first.


Acoustic impact: 0.02% bass reflex frequency

Well, with these speakers being nearly 20 years old I wouldn't have to worry too much about warranty 😁

Ad for the impact on sound quality: adding a cubic centimeter of wood is reducing the internal volume with a cubic centimeter. Well... That's a 0.02% change in volume thus bass reflex frequency. I think I can live with that. ..


Taking the fifth...

I modified all eight speakers to have some spares. Here's my production line 😏 You also can see the different kinds of dampening, compare the 'Made in China' (6x) and 'Made in Taiwan (2x) versions.


I mounted four thus far, but I plan to install number five directly above the listening position for the VOG 'Voice of God' channel in Auro3D. I guess I'll find little material to ever test it, and I'll need an additional amp to use it, but why not. Safety is even more mandatory in that position, I guess 😇

The fifth VOG speaker will require a different kind of mount as it is going to be mounted directly against the ceiling. Unfortunately my SR7011 in 7.4.1 has some amp channels left but doesn't allow me to route VOG to an amp, so I have to add one more box... sigh.

Will be continued...


Artsy

Completely unrelated, but I have never seen a speaker repainted as much as these monitors. Weird... though probably inspired by some factory color combinations. (I know there have been some different color combos but I could never find out which ones were official.)








3 comments:

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  2. Nice reading about your Solids. What further enhances the quality of the bigger Solids, is to put a brace between the side-walls. No need to do some 'precision engineering' or even permanent solution here. Wedge a piece of wood in between dead center, which are held in place by patches of thick fabric on both sides. Then do the knock-knock test on the casing. You'd be surprised. GOne is the slightly hollow sound. Which is good.

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  3. Good idea. Currently my Solid's are all mounted against the ceiling, but I was thinking about using a pair as my desktop monitors (I do have a few spare), so I'll give it a go.

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