|
Post by nelsondog on Dec 4, 2006 0:22:48 GMT -7
HI guys, I live in BC, Canada it can get quite cold here in the winter months -20c ~ -30c for a few days in the season. I'm wondering if the Mach 5 MJ-18 will be ok if I run the system in these low temps... I'm thinking that the rising warm air from the house will gather and condensate on the woofers causing frost or even ice... and what about the foam surrounds? Can these drivers take the stress of the elements?
|
|
|
Post by chrisbee on Dec 4, 2006 2:11:07 GMT -7
This must be a common worry to those with a loft installation. It certainly occurred to me when I was going to put a manifold in our well-ventilated roof with occasional sub -20C nights.
It depends whether the rising warm air is able to carry moist air to the metal parts of the driver. Driver cones are air tight and therefore moisture-tight. If the metal pars are on the warm side then the cone will help to protect them from extreme cold. The metal will remain at a higher temperature than if it were directly exposed to the cold air of a loft.
If the metal parts are on the cold side of the cone then moisture cannot reach them through the impervious cone. The metal parts will get cold but remain dry unless they lag behind rising temperature swings of the air surrounding them.
Should icing occur it should hopefully not affect the moving parts. All the metal parts should be plated or treated to protect them from corrosion.
Thomas has said that car audio installations suffer much greater extremes of temperature than any home speaker installation. Moisture and extreme cold are commonplace in many vehicles.
The supplier of the MJ-18 may be able to offer further encouragement to allow you to continue to enjoy your drivers at -30C.
|
|
|
Post by Darren on Dec 4, 2006 7:41:23 GMT -7
My IB has been through 12 degree F without issues... Of course the attic is much warmer than the outside temp. I'd say my attic never gets below freezing.
|
|
|
Post by PeterW on Dec 4, 2006 9:21:07 GMT -7
I live in Red Deer Alberta, the hot air rising from the rest of the house seems to make our attic quite warmer than room temperature. Im guessing that the temperature in the attic can reach 303K to 313K, ;D I would suggest taking a peek in your attic and checking the temperature during a cold spell this winter nelsondog..
|
|
|
Post by ThomasW on Dec 4, 2006 13:07:41 GMT -7
It's hard to imagine a situation where frost could form on parts of the woofer where one side is in a heated living space, and the other side is in the attic above that same living space.
Putting them in a window or exterior door where the back side is exposed to the elements, could result in frost on the metal surfaces.
|
|
|
Post by chrisbee on Dec 4, 2006 16:42:55 GMT -7
If you're really worried about ambient temperatures in your loft get a cheap digital room thermometer. One with an "external" sensor on a very long lead. Put the sensor up near your manifold and the display panel somewhere handy. Some of these things have up to 15 feet of thin two core wire on the sensor. You can even get wireless models with a battery powered "outdoor" sensor. It's a cheap and easy way to monitor what is actually happening up there. Who knows, you may even consider investing in some more insulation to save the planet if it's too "cosy" up there.
|
|
|
Post by pcloadletter on Dec 30, 2006 8:25:02 GMT -7
Attics should be vented and should not be warm. There should be plenty of insulation on the floor of the attic, but if you remove this to install a sub, you are creating a hole for the cold air to come through. I know that speakers are sealed, but a 1 mm thick cone will not provide much insulation. Running the speaker in the cold should be fine, just look at car applications. I am planning on a IB in the floor since my crawlspace is heated.
|
|
siggy
New Member
Posts: 3
|
Post by siggy on Jan 4, 2007 4:19:08 GMT -7
Hi, I live in Norway and I have some experience with frosty woofers. My old IB was icy some mornings, but it did not seem to damage the metal or the rubber(short term?) but you could hear damage to the performance. The lack of bass was reduced somewhat, when I turned the woofers "insideout" and the voice coil and rubber warmed up. At www.zaphaudio.com/temp.html you an read about the ill effects, especially on fs and vas, in cold temperature.
|
|
|
Post by ThomasW on Jan 4, 2007 8:22:13 GMT -7
It's standard operation proceedure to 'heat' up a driver before measuring T/S parameters. Zaph's measurements show the effects a cold driver. Smart thinking to reverse the drivers in your IB....
|
|
|
Post by chrisbee on Jan 5, 2007 1:06:34 GMT -7
Hi, I live in Norway and I have some experience with frosty woofers. My old IB was icy some mornings, but it did not seem to damage the metal or the rubber(short term?) but you could hear damage to the performance. The lack of bass was reduced somewhat, when I turned the woofers "insideout" and the voice coil and rubber warmed up. At www.zaphaudio.com/temp.html you an read about the ill effects, especially on fs and vas, in cold temperature. Hi siggy Did you notice any change in the sound quality as a result of reversing your drivers?
|
|
siggy
New Member
Posts: 3
|
Post by siggy on Jan 5, 2007 7:44:38 GMT -7
Hi , Chrisbee. The warm up time became shorter, and the low frequencies came sooner.Other than that, there was little differency in sound quality. Maybe at low volumes, when playing music on the coldest days, it is hard to tell... I have alu cones (Dynabel 9215)
|
|
|
Post by chrisbee on Jan 5, 2007 10:45:43 GMT -7
Thanks, siggy.
That's good to know.
Because of wall flexure I was thinking of changing my line array to a manifold. That means two of the driver magnets would have to go inside the manifold just so I can open the door to the enclosure. If the SQ was poor with the magnet side firing into the room I wouldn't bother to change to a manifold.
Though unheated, my enclosure doesn't go much below freezing. From what you say I don't think it's worth my building a ceiling manifold with local temps down to -20C most winters.
It's very useful having forum members with direct experience of such details like low temperatures. It takes a lot of the guesswork out of IB building.
|
|