Monitor Audio R252

[karma67]

the ferrofluid arrived today,so after work i got too it.
i was pleasantly surprised to find i didn't have to desolder the voice coil,phew!
interestingly there was still quite a bit of the old fluid still present.
i very carefully lifted off the voice coil and cleaned out the old fluid and re-filled with the new,about 15 mins each tweeter.
happy days!

here's a vid showing my sausage fingers in action!
THE BEST BIT IS THEY STILL BLOODY WORK TOO!!


[IMG]IMG_1166 by jamie creighton, on Flickr[/IMG]

[system7]

Marvellous, Jamie.

Enjoyed watching that.

Give your tweeter a ferrofluid oil change!

I can only tell you my ferrofluid had turned to thick sludge like bovril in the SEAS 19TAF/G Monitor Audio tweeters. They weren't doing much.

http://www.bluearan.co.uk/index.php?...e=manufacturer

This stuff is actually very hard to buy. £5 for 5 applications isn't bad.

Makes your tweeters tweetier.

[karma67]

cheers steve,
they do sound a bit better for doing it,treble seems a bit smoother.

[system7]

You can make an interesting comparison of the effects of ferrofluid on tweeters with these two, otherwise identical, SEAS aluminium metal domes. Expand the frequency response and tab between the two. Ferrofluid tends to make tweeters recover quicker from overload and heat.

Without Ferrofluid: http://www.seas.no/index.php?option=...ers&Itemid=462

With Ferrofluid: http://www.seas.no/index.php?option=...ers&Itemid=462

You can see the slight resonance issues in the supersonic range around 27kHz. CD really shouldn't produce any output above 18kHz, but amplifier stability may be affected into distortion. And, of course, there is that slightly zingy metal sound.

I want to show you a modelling project on first order versus higher order filters. IMO, you could actually modify your speakers into something resembling those very fine £2000 Harbeth designs, which also pay great attention to damping the cabinet resonances with stick-on rubbery pads and stuffing. The 7.5R and 0.68uF is called a Zobel network. It tends to tame a rising HF response and give the amp a better load. I'll let the images speak for themselves.

Components available at Wilmslow Audio mostly. http://www.wilmslow-audio.co.uk/supe...itors-68-c.asp

The reason we do higher order filters, is they keep drivers more in their comfort zone, so they go louder and play more complex music like classical with less distortion. Your speaker is a whole lotta fun, I'd guess, but you could take it higher.

Harbeth_Compact_7ES-3.JPGS7 1 Monitor Audio R852 Circuit.jpgS7 2 Monitor Audio R852 1st Order FR.jpgS7 3 Monitor Audio R852 3rd Order Circuit.jpgS7 4 Monitor Audio R852 3rd Order FR.jpg

[karma67]

unfortunately steve that's a bit above my head,i can solder but wiring diagrams and theory are beyond me unless explained in layman's terms .

[brian2957]

I have a pair of Monitor Audio r852s Jamie and would like to try this . Unfortunately I can't get your video to work.

[karma67]

try this link Brian https://www.flickr.com/photos/145822...2/32368540116/

[brian2957]

Nope , not working mate . Just a black screen . It's probably at my side

[karma67]

no worries,theres a few vids on youtube plus the one steve posted. if you do it just be extremely careful removing and putting back the voice coil as the aluminum dome is paper thin.

[brian2957]

OK thanks Jamie , I'll have a look