So what kind of sensitivity improvement are we looking at here in figures?
About 1 to 2dB for the types of driver I‘m used to using. Sometimes you want a 97.5dB/W driver instead of 96 - this is what you’d get going from 67 grams to 48 on a 12”. With really light cone drivers the delta can go a bit higher. Of course, fs does go up here, but that’s ok for a dedicated midrange. You might think “whoopee, I can just drive it with more watts it’s only 2 dB”, but that won’t help the mass corner when driving a midrange horn or get that dB or two back on a 4 watt tube amp.
CCAW is a bit tricky. You can’t always solder to it so if anything tears up you’re looking at full replacement (Reconing not always successful - re-leading always impossible because once it’s been soldered to and de-soldered the plating comes off).
CCAW is a bit tricky. You can’t always solder to it so if anything tears up you’re looking at full replacement (Reconing not always successful - re-leading always impossible because once it’s been soldered to and de-soldered the plating comes off).
There is some British Ersin Multicore solder specifically dedicated to pure aluminum, but I never could get some.
Sometimes used Plan B is to crimp voice coil aluminum wire to copper tinsel wire, then apply a drop of glue to joint, both to mechanically fix it to cone and to isolate it from free air.
It is supposed to become a corrosion troublemaker if not.
Crimping is as simple as slipping both together inside a nickel plated brass tube and crushing it.
Sometimes used Plan B is to crimp voice coil aluminum wire to copper tinsel wire, then apply a drop of glue to joint, both to mechanically fix it to cone and to isolate it from free air.
It is supposed to become a corrosion troublemaker if not.
Crimping is as simple as slipping both together inside a nickel plated brass tube and crushing it.
This wire directionality reminds me of what my building inspector said. He told me to make sure the logo side of my Tyvek house wrap faces to the outside.
Poor guy has been suckered by the marketeers.
Poor guy has been suckered by the marketeers.
Don't know about your house wrap but Tyvek roof underlay should be installed product name facing upwards as it is directional.
Tyvek wrap/underlayment products are directional - the two surfaces do NOT look the same. It is effectively more porous in one direction. Ditto for the OSB board that goes on the studs/rafters/joists. Trader - you would hate to find out that your tyvek or osb were installed backwards when the building inspector shows up.
Hopefully you’ll get the connection gas-tight. Easier said than done quite often. May sound fine for a while but not last. The same problems which cause electrical fires with AL wire make audio circuits (that includes speakers) sound bad.
By the way - such a circuit is quite directional. Passes DC a little better in one direction than the other.
One of them, maybe, won´t argue that.
But the whole circuit becomes symmetrical, you have electrons/current jumping from copper to aluminum at one end of the VC, then from aluminum to copper at the other end.
And when you reverse polarity, exact same happens, only starting from the other end.
Agree that you might have some nonlinearity there, but that does not make it asymmetrical or directional when passing Audio current either way.
But the whole circuit becomes symmetrical, you have electrons/current jumping from copper to aluminum at one end of the VC, then from aluminum to copper at the other end.
And when you reverse polarity, exact same happens, only starting from the other end.
Agree that you might have some nonlinearity there, but that does not make it asymmetrical or directional when passing Audio current either way.
Yeah, with AC it would sound the same with either polarity - pretty much. At small signal levels it sounds the same if you stick a 1N4001 in series with the speaker in either direction. Run a speaker motor hard enough, though and it will have its own rectification effect due to flux modulation. That can interact with a partially rectified incoming AC signal - even just the 2HD produced by the amplifier, so it could potentially sound different reversed. By the time you add that much distortion no one interested in fidelity would care anymore, though.
I'm talking about Tyvek house wrap (WRB). Do you have any proof that it is directional?
My point is that its better for marketing that the logos are exposed to passers-by during construction. I don't have any reason to believe it is functionally directional.
You know ive put up miles of this stuff dating all the way back to the transition from tar paper, and ive never read the data sheet! I can tell you one thing if you‘ve ever actually put it up its a heck of a lot easier to roll it out in the way the words end up out (i reckon dupont knows that!) so in that case it is indeed directional.
you laugh Bill but i can remember as a kid having to save the winter coat from our horses when brushing them out in the spring…..our house was a old farmhouse with lath and plaster walls and according to grandad mixing horsehair with the plaster was the ‘correct’ way to patch it…….of course we always had burlap sacks full of it already from years gone by. My aunt took over the place when they died, i‘ll bet theres still a dozen bags covered up in the barn ! 🤣
That’s certainly what we used in the plaster in this country. Makes an awful mess when you take it out.
Correct, synthetic house wrap is not directional, nor is roof underlay. The difference in the roof underlay having different surfaces is due to the increased friction aka better grip.
To make it directional would be almost impossible. It is intended to pass water vapour but not water droplets. Tell me how you would make that directional. Great idea but not really necessary.
To make it directional would be almost impossible. It is intended to pass water vapour but not water droplets. Tell me how you would make that directional. Great idea but not really necessary.
This is from the Tyvek Supro roof underlay certificate which must be followed for correct installation:
"2.4.3.2 Both products should always be laid horizontally, parallel to the eaves with the grey non-woven PP and product name uppermost."
All breathable roof underlay membranes I've worked with have different surfaces. Whether or not it is for grip or UV protection these membranes should be installed one way only making the directional.
"2.4.3.2 Both products should always be laid horizontally, parallel to the eaves with the grey non-woven PP and product name uppermost."
All breathable roof underlay membranes I've worked with have different surfaces. Whether or not it is for grip or UV protection these membranes should be installed one way only making the directional.
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UV protection doesn't apply as it is an underlay. Yes, the grip is why you have the 'label' side upward. It also helps in advertising as it can be exposed for a few days before being covered and may be seen from the ground.
I guess you could use gore-tex for the membrane. Batsrad expensive way to do it but (if memory serves) as long as the temp inside the roof is higher than ambient vapour would go out. I'll get my coat...