Painting the 2K array black + tuning the M109

[k_numigl]

This is a real DIY problem: I am in favor to replace my (very old) Kans
by a pair of Majik 109s. However, the silver 2k array looks quite obnoxious to me, and the speaker is not available with a black array. Unfortunately, there is no front cloth or grill either... Has anyone tried to change a silver array to something less aggressive? Paint it? scratch it? sand it?

Or alternatively attach some kind of cloth to the speaker's front? As you
may notice, I would be prepared to make quite an effort to get rid
of the silver beast. So if there's any idea which does not ruin the sound,
I would be glad to get advice.

I am not unhappy with my Kans - despite their age they reflected every
upgrade of the LP12 very beautifully. It just happened that I listen to
this system so much, that I thought an upgrade would be worthwhile.
Speakers are driven by a brick style Majik.

Regards, Klaus

[k_numigl]

I'm going to put some fabric in front, as I finally don't dare to touch the
2k-array. I'll use a leftover from a Kaber (fabric) and either have a frame
cut out of a piece of plywood and attach it to the front of the speaker
(as described here some time ago for a Kan grill replacement).
Or take a router and mortise a 2mm channel into the speaker sides - say
15 or 19 mm from the front - in order to attach the fabric with a sewed in
large O-ring. Frame solution first, as it is easier and speaker modification
is less extensive.
As you may notice, I'm planning to live with the speakers for a time
comparable to that I did with the Kans.......
K.

[lejonklou]

Hi Klaus!

Don't Linn have any optional grilles for the 109's? Just a thought before you make your own.

I will paint my pods black, just haven't had time to do it yet. Will report how it worked out as soon as I've done it.

[Lego]

Hey Fredrik you could try the Black paint Leica use;

http://mir.com.my/rb/photography/compan ... k72x-4.jpg

[k_numigl]

No, there's no grill available from Linn. I would have been more than
happy to use it. Klaus

[lejonklou]

Ok, I have taken a closer look at this. First of all, the 2K array is a pain to remove and put back, so reserve plenty of time to fiddle with it.

It's also practially impossible to confirm how tight the metal array (secured with 2 screws from the back) should be for optimal sound, and almost as difficult to try different torques on the plastic pod/cavity/port (secured with 2 bolts to the baffle, from the inside). This annoys me a bit, as I know the difference it can make to optimise these things.

Secondly, I tried some different paints on a similar metal surface and I'm not happy with them. 5 different pens all proved to be uneven in colour and an enamel paint resulted in a surface that was slightly uneven. Probably not visible from a distance, but I'm afraid I'm too much of a perfectionist to accept it. Spray painting would require very good covering of the drive units, which appears difficult (without covering any of the silver metal).

Project put on hold for the time being. :(

[k_numigl]

Mine is progressing, but slowly. I decided finally to use a 'non
destructive approach' in order not to make a later resale of the speakers
( I'm not thinking of it now at all) more difficult or to potentially
compromise its performance before I know this is the final solution.

The idea is, to cut a grill from plywood (8 mm), have this in front of the
speaker, cover it with 'acoustic' fabrics, and hold it by two rubber
strings (ok, it's some better kind of rubber: Neoprene shore 50 with 3 mm
diameter) running round the back of the speaker. This is a clearly visible
solution, but I do not oppose generally to visible constructions. And this
nicely tells you that you had to fix a problem Linn did not care about.
(Is it true that the Akurate speakers have grills fixed with magnets?
I never saw a picture with a grill on them.) I just remain to find some suitable fabric.

When finished, I'll post a picture.

Regards, K.

[JW]

Is it true that the Akurate speakers have grills fixed with magnets?

I only have experience with the 242, and for the 242 the answer is "yes".

JW

[ThomasOK]

Anyone considered the idea of attaching some adhesive-backed black felt to the front of the 2K array? It seems this would make it black, reduce sound reflecting off the metal (which could make it sound better, or worse) and be removable without causing damage. I know the fabric stores around here sell 8" x 10" sheets of it pretty cheaply - as I found out after checking on how much Linn wanted to charge me for those little Trampolin felt strips!

Just thought I'd throw this out as an idea. If done right it should look pretty good from a normal distance, possibly even not too visible close up.

[lejonklou]

Felt is an idea, but it will certainly affect the sound. I have tried felt around various treble units and it has a strong dampening effect on certain frequencies. On loudspeakers that have been good to begin with, it has so far been a serious downgrade...

I am still on the track of enamel paint. Will try making it thinner to see if I can get the surface more even. That silvery pod really does annoy me on my black 109's.

Speaking of the 109's, has anyone had a look inside it and noticed the small foam dampening block directly behind the port? It's also visible from the outside, through the port (torchlight needed). On one of my speakers, this piece of foam was almost completely covering the rear end of the port. On the other, it was a bit more angled away from the port. Thus leaving more room for air to move past it.

My question is: How is that piece of foam supposed to be installed?

[k_numigl]

When I look through the port into the speaker, I see the backside end
of the port to be completely free, and in a certain distance from it
a foam block. This is installed at a horizontal angle, left hand more to the front, right hand more backwards. Whether it is completely vertical, is difficult to estimate - seems it is a bit tilted backwards on top. Same in
both speakers. In one of the speakers there is a tiny bit of another foam
piece visible, lurking from behind the port's downward end into the
channel area. This makes me wonder how these pieces are secured.
If they are not properly fixed, transportation would endanger their
positioning.
I fear, that's all I can contribute...
K.

[lejonklou]

Thanks, Klaus!

These foam blocks are just pushed in between the side walls. It seems yours are away from the port, while mine were both squeezed between the upper surface of the port and the top surface of the speaker - and then angled downwards away from the port.

I might have to practically check how close to the port they really should be for optimal sound. But it's not exactly done in a few minutes...

On Katan and Tukan, the port was enclosed inside a small box with thick cloth on the sides. Therefore I suspected this foam block might be intended as a damping of the port. But perhaps it should just sit at the rear wall, across the crossover, and not damp the port at all.

Does anyone know if it's mentioned in an aktiv conversion manual or any repair manual?

[k_numigl]

Fredrik,
the distance between the channel's rear end and the foam block
is 3.5 cm for both of my speakers. It's easy to measure, sorry
I missed to do so before.
Best wishes, Klaus

edit 26.11.2009:
In order to specify better than in the above text: 'rear end' means
the groove at the end of the plastic channel you can easily see.
This is of no particular importance, see Fredrik's next entrance.
But it shows how far this piece can move from its optimal position.

[lejonklou]

Thanks. Please note that the port ends with a flare; an expansion of the diameter. It's a bit more difficult to measure the exact distance from that, from the outside.

I've caught a bad cold, so I have only managed to make a 5 minute experiment today before I landed on the sofa. But it was quite interesting:

This foam block should cover the rear end of the port!

As soon as I put it in that position, its purpose became obvious: To prevent midrange noise from inside the speaker to exit through the port. Just like the small boxes around the port on Tukan and Katan.

The effect is really pronounced: More clarity and articulation in the midrange, more tuneful and enjoyable. The bass becomes a little more damped, but I wouldn't say it changed in a negative way. Rather it became more pitch accurate and less blurry and fat.

One problem with keeping the foam block in this position is that below it, there is the large roll of white polyester wool (the one that you've seen through the port, Klaus). When that is pushed in, standing up, it can easily push the foam block away. I haven't yet figured out the optimal position for this wool, but will do that as soon as I get well. Right now mine are in an angle, so that the top goes behind the foam block.

If you give this a try, please report. For me, it was very worthwhile!

[Music Lover]

:shock:
M109 QC?

Is it same in other Linn speakers?

[k_numigl]

Thanks for the advice! But how can I access this piece in order
to move it to a better place?

[lejonklou]

Through the bass unit hole. This is what you need to do:

First remove the grille and rubber surround. These are attached to eachother, so you need to insert a thin blade or another sharp object between the rubber surround and the wooden baffle. Then bend the rubber out and the entire grille+rubber will pop out. Just be careful not to damage the wood; direct the pulling force towards the center of the speaker, away from the wooden edge.

Next you loosen the 6 bolts that hold the bass unit. Lift the bass unit out and place it with the magnet down on something beside the speaker. Notice how many turns the cable has from filter to bass unit. On one of my 109's, it was 6 turns. On the other, it was 11. I'm not sure yet which number is optimal.

Now you have access to the white roll of polyester woll. Just grab it at the bottom and pull it out. Then you'll see the foam block behind the port, squeezed in between the sidewalls. If the foam block is bent (mine was), it can be taken out and massaged until it regains its normal shape.

When putting it all back, notice how there is a small mark in the rubber surround. This should point up and helps you orient it so that it pops back in easily.

[k_numigl]

Thanks again for valuable advise, F.! I agree that this position of
the foam block improves the speaker (with other words, the wrong
position degrades it). Access to it was easy enough
when you know where to start opening. The finding, that the foam block
should be positioned directly behind the port is confirmed by Glasgow, btw.
Regards, K.

[lejonklou]

Nice to hear that Linn confirms this position. I found my speakers to improve quite a lot with this fix. Mainly voices have become more expressive and easier to follow than before. I'm enjoying the 109's more than ever, great little speaker!

I have been a bit surprised by the lack of response to this discovery. It seems several other 109's also suffer from the same incorrect position of the foam block, which means the owners don't get the full potential these speakers can bring. (In response to ML: Not sure about other speakers, will examine the Majik center soon.)

How did you place the white roll of polyester wool, Klaus? I assume that its main purpose is to dampen midrange frequencies that will otherwise resonate between the side walls. If so, it might be better to have the wool folded in a different way, perhaps sideways. The side walls each have one piece of bitumen damping pad on the inside. If you listen to the sound these side walls produce when the speaker is playing, you'll probably be surprised by how loud it is. I think that for anyone with time on their hands, it's possible to make some kind of mod here that will improve the 109's even further.

[k_numigl]

I just left it as the roll it was. But I realise you can do many different
things with it - I just thought the Linn guys tested it to the optimum. But then,
who knows how big the difference between the intended design and
the final product might be? (See foam block.)
K.

[lejonklou]

I don't understand.

I can't leave my white roll as it originally was. It pushes away the foam block! Your roll must somehow look different.

[k_numigl]

Interesting. I took some snapshots, but I guess I can explain the situation well enough: The roll was loosely wound up, and oriented diagonally from bottom back to top front. So its upper end was stuck under the port channel. The roll's diameter was small enough not to push the foam block backwards. The foam block is indeed not fixed by anything except the pressure by which it sticks between both sides of the speaker. As the width of the block is very slightly larger than the distance between the speaker walls, the foam block's centre bends a little bit forward.

Regards, Klaus

[Patrik]

This foam block should cover the rear end of the port!

As soon as I put it in that position, its purpose became obvious: To prevent midrange noise from inside the speaker to exit through the port. Just like the small boxes around the port on Tukan and Katan.

The effect is really pronounced: More clarity and articulation in the midrange, more tuneful and enjoyable. The bass becomes a little more damped, but I wouldn't say it changed in a negative way. Rather it became more pitch accurate and less blurry and fat.

I have recently gone active with my 109's and Lejonklou did the tuning of the speakers. Fredrik also did the foam change as stated above. As expected the music was much better compared to my own trials. The sound was extremely analytic though. The bass so thin, dry and defined with a total lack of bluriness. So in a way the sound was very impressive. But I felt something was wrong. It was a bit like watching photographs on a monitor with to much contrast and artificially sharpened.

I consulted Linns helpline. Sometimes people report they get strange answers, so I was persistent to get the designer of the 109's to specify exactly where the foam piece should be positioned. I was asked also to send photos of the inside of the cabinet, (I suppose so no misunderstanding could occur), which I did.

The answer I got was that :"The foam should be just about touching the crossover, ensuring that there is at least a 25mm gap between the port and the foam."

I did that and was pleased with the result. The sound is not so hyper clean as before, partly I suspect becuase higher frequences are leaking out of the port. The bass is stronger but less tight. However I cannot swear that the tune has improved. I did not do a proper tune dem. It feels a lot more natural now. Perhaps my room really needs the port to be fully open and some bassy rooms benefits from moving the foam. Now I can also listen to music at higher volumes and really enjoy it. With the port "closed" the sound was so in my face that I couldn't stand it.

[lejonklou]

Thanks, Patrik! Highly interesting.

My first reflection is that all M109's I have seen have had that foam block directly behind the port. Not 25 mm away as the designer says.

The second reflection is that I've already tried this, and didn't like it. But I could be wrong, so I will probably have to try it again.

Third one is that there might be a simple way to improve the 109. It's obvious that the port transmits midrange noise from inside the cabinet, and this is unwanted. If the foam block provides too much damping for the low frequencies, perhaps the optimal solution is to push the block away (as the designer says) and then add something else in between the block and the port! Something that will filter higher frequencies and leave the lower ones alone. The foam block is hardly ideal in this respect.

Ideas, anyone?

[Efraim roots]

I finally took myself time to do this mod on my 109's. My foamblocks was from the beginning not straight, on one side the foam touched the tube flare while on the other it was 15mm away from the tube flare(sideways). The speaker wire was twisted 10-11times (wasn't very careful when counting). I tried both ways as described in this thread. First with the foam block up against the port and I was impressed by the difference, very much as Lejonklou describes it. I then tried with the foam 25mm away from the port and it was also good but beacause the time it took for me to change the positions it was hard to make a proper tune dem statement. I still decided to go back to the foamblock up against the port and I think I prefer this way, I think this sounds more right. Maybe it sounds more analytical (clear) but also better was my conclusion, easier to follow the music.
How about the white roll, how should position this? Anyone tried what's best? I put it so the top was touching the tube and about equal covering of sidewalls and bottom, not pushed deep in the box.