trittya
Active Member
Greetings ALL
This thread is in response to a query to the said effect by FMs Bluu and Inderbir here
http://www.hifivision.com/sale-owner/17103-mission-speakers-denon-avr-3.html
Unknown to many, the mission m series of floor-standers have a back-loaded cavity at the bottom of the speakers. This is meant to be filled with sand or an alternate material for weighing down the speaker with an aim to cut out the 'boom' in the bass and lo-mid frequencies. It does go a long way towards serving the intended purpose.
The sand(approx 9-10 kgs or more) must not be 'gravelish' and coarse but fine and comprising of fine near-round granules. Riverine white/silver sand with minimum (flaky & shiny) silica content is most preferred. Nevertheless, it still has to be washed thru a very fine steel sieve to make the powdery sand-dust flow away.
Dry the sand for a day in bright sunlight by spreading it on an old bed-sheet or the like.
Roast the dried sand in an open cast iron 'KADAHI'/'WOK' measuring at least 2 ft in dia.
Keep stirring and turning the sand till uniformly hot.
Test heat of sand by throwing in a maize seed. If it pops and turns to a popcorn flake, its just right but dont take it off just yet. Let the sand roast for another 20 min, turning it over occasionally. Be careful, that sand is worse than 'red-hot'.
Let the sand cool down naturally, be patient, stir occasionally to aid cooling. Then let it rest after warm to cool down totally.
Add about one large peg each (60 ml each) of concentrated fungicidal liquid to prevent moulding/fungal growth.
Stir fungicide well into sand, if need be, add a wee bit more.
Let the fungicide dry completely, allowing the smell to subside substantially.
Make you spkr lie face down, dont remove the cloth grilles and do ensure that you prop the face on a couple of soft pillows or the like.
Make sure spkr is fully horizontal.
Remove plastic cover of cavity below the port on the rear.
Fill in about 1.5' - 2" of sand, tapping gently on the cabinet sides with the heels of your palms to make the sand settle.
Throw in a small handful of air-gun pellets(preferably the spike-tipped double-head ones)
Do spread the uniformly over the sand.
Pour in another 1.5' - 2" layer of sand and repeat the pellet routine.
Be patient and keep tapping the spkr cabinet gently all through.
Repeat above process till u reach the top with the cabinet empty enough just to let the cover fit in place. Throw in another handful of lead pellets before putting the lid back on.
Seal the lid with silicone caulk/ sealant(turns to silicone rubber on contact with air and can easily be peeled off).
Place some old heavy books over the lid to ensure sealing. Leave for 24 hrs before making spkr upright.
Repeat with other speakers.
Glasswool and lead pellets is another option.
Will talk more on that after hearing from you guys.
Hope this helps.
Regards
This thread is in response to a query to the said effect by FMs Bluu and Inderbir here
http://www.hifivision.com/sale-owner/17103-mission-speakers-denon-avr-3.html
Unknown to many, the mission m series of floor-standers have a back-loaded cavity at the bottom of the speakers. This is meant to be filled with sand or an alternate material for weighing down the speaker with an aim to cut out the 'boom' in the bass and lo-mid frequencies. It does go a long way towards serving the intended purpose.
The sand(approx 9-10 kgs or more) must not be 'gravelish' and coarse but fine and comprising of fine near-round granules. Riverine white/silver sand with minimum (flaky & shiny) silica content is most preferred. Nevertheless, it still has to be washed thru a very fine steel sieve to make the powdery sand-dust flow away.
Dry the sand for a day in bright sunlight by spreading it on an old bed-sheet or the like.
Roast the dried sand in an open cast iron 'KADAHI'/'WOK' measuring at least 2 ft in dia.
Keep stirring and turning the sand till uniformly hot.
Test heat of sand by throwing in a maize seed. If it pops and turns to a popcorn flake, its just right but dont take it off just yet. Let the sand roast for another 20 min, turning it over occasionally. Be careful, that sand is worse than 'red-hot'.
Let the sand cool down naturally, be patient, stir occasionally to aid cooling. Then let it rest after warm to cool down totally.
Add about one large peg each (60 ml each) of concentrated fungicidal liquid to prevent moulding/fungal growth.
Stir fungicide well into sand, if need be, add a wee bit more.
Let the fungicide dry completely, allowing the smell to subside substantially.
Make you spkr lie face down, dont remove the cloth grilles and do ensure that you prop the face on a couple of soft pillows or the like.
Make sure spkr is fully horizontal.
Remove plastic cover of cavity below the port on the rear.
Fill in about 1.5' - 2" of sand, tapping gently on the cabinet sides with the heels of your palms to make the sand settle.
Throw in a small handful of air-gun pellets(preferably the spike-tipped double-head ones)
Do spread the uniformly over the sand.
Pour in another 1.5' - 2" layer of sand and repeat the pellet routine.
Be patient and keep tapping the spkr cabinet gently all through.
Repeat above process till u reach the top with the cabinet empty enough just to let the cover fit in place. Throw in another handful of lead pellets before putting the lid back on.
Seal the lid with silicone caulk/ sealant(turns to silicone rubber on contact with air and can easily be peeled off).
Place some old heavy books over the lid to ensure sealing. Leave for 24 hrs before making spkr upright.
Repeat with other speakers.
Glasswool and lead pellets is another option.
Will talk more on that after hearing from you guys.
Hope this helps.
Regards
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