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CHUCKmfnNORRIS
11-06-2010, 03:38 PM
plan on getting an ssa icon and have the choice of aluminum and copper. what is the difference?

VWBobby
11-06-2010, 03:42 PM
Usually weight and power handling. In general, copper can handle more power but it weighs more. IMO, an aluminum coil sub will respond faster, sound better, but usually can't handle as much power until you get into larger coil diameters or heavier gauge windings.

CHUCKmfnNORRIS
11-06-2010, 04:02 PM
this (http://www.soundsolutionsaudio.com/store/products/12%22-SSA-ICON-12D1%7B47%7DD2.html) is the one i am looking at

loud-n-low
11-06-2010, 06:11 PM
Usually weight and power handling. In general, copper can handle more power but it weighs more. IMO, an aluminum coil sub will respond faster, sound better, but usually can't handle as much power until you get into larger coil diameters or heavier gauge windings.

Dont more often then not, SQ oriented subs have a copper coil, therefore a lower Fs?

jdawg
11-06-2010, 06:34 PM
aluminum coil subs usaully have a higher fs

CHUCKmfnNORRIS
11-06-2010, 08:02 PM
"fs"?

denim
11-06-2010, 11:27 PM
Fs is the resonant frequency of the driver. The Aluminum coil option is for people who are going to really abuse the driver and push it too its power limits and want a little more peak in their output.

Haunz
11-06-2010, 11:47 PM
All things considered, copper is the superior conductor. period.

Aluminum is cheaper :fyi:

CHUCKmfnNORRIS
11-06-2010, 11:55 PM
Fs is the resonant frequency of the driver. The Aluminum coil option is for people who are going to really abuse the driver and push it too its power limits and want a little more peak in their output.

ok i got ya now

hatedonmostly
11-07-2010, 12:20 AM
Fs is the resonant frequency of the driver. The Aluminum coil option is for people who are going to really abuse the driver and push it too its power limits and want a little more peak in their output.

This is the only answer.

SPLaudio
11-07-2010, 09:21 AM
if both coils are = then the alum will be louder. the copper will handle the power betterfordaily though...

denim
11-07-2010, 08:12 PM
if both coils are = then the alum will be louder. the copper will handle the power betterfordaily though...

The coils are not equal in this case, so the aluminum have a little higher thermal limits.

SPLaudio
11-07-2010, 08:29 PM
alum cools faster yes but why its louder is weight.

VWBobby
11-08-2010, 11:57 AM
Aluminum cools faster but I thought part of the job for the former and the gap is to cool the coil?
A heat conductive former will draw heat out of the coil and cooling vents for the gap, exhaust the heated air.
Aluminum wiring in houses tends to burn, that's why they switched over sometime in the 70's for safety reasons.
I would imagine you would have to have a lot heavier gauge aluminum to equal the power handling of copper?

hispls
11-08-2010, 12:02 PM
alum cools faster yes but why its louder is weight.

X2 MMS is a HUGE factor in efficiency.

sundownz
11-08-2010, 12:03 PM
Aluminum wiring in houses tends to burn, that's why they switched over sometime in the 70's for safety reasons.

This was due to dis-similar materials on the connectors with varying expansion ratios loosening over time - thus creating heat from the loose connection and eventually fires.

sundownz
11-08-2010, 12:11 PM
The real factor is the ratio of motor force factor to the MMS and not just MMS... unless you are running a very high frequency where the downward shifting FS will hurt score with the copper.

Example:

Z v.2 Copper ratio is 0.59
Z v.2 Aluminum ratio is 0.62

My testing showed zero SPL difference between the two coils -- in theory the aluminum should have been 0.1 louder based on the ratio but in real life they metered the same... up until over 6kw where copper was a bit louder as power compression was lower.

But on the SA-8 :

Copper : 0.51
Aluminum : 0.54

In this case they are also still very close... but we tested at 68 Hz -- so the much higher FS of the aluminum coil overrode the ratio and gave us a gain of ~0.8 dB or so.

Haunz
11-08-2010, 08:53 PM
alum cools faster

The thermal conductivity of copper is considerably greater then aluminum... :fyi:


This really isn't rocket science.. with one aluminum and one copper coil of equal mass, wind height, adhesive, former, ect, the copper coil will handle slightly more power.. additionally, because the windings of the copper coil will be considerably smaller you can use a tighter gap for increased BL...


The only reason to use aluminum, as far as I am concearned, is to save money.... (same as with house wiring)

SPLaudio
11-08-2010, 10:16 PM
copper takes longer too cool. you wont have a copper and alum coil the same ww and same weight,lol. tighter gap than copper use alum flatwound. are you mad frenchy?

Haunz
11-09-2010, 09:04 PM
copper takes longer too cool. you wont have a copper and alum coil the same ww and same weight,lol. tighter gap than copper use alum flatwound. are you mad frenchy?


If you want to compare apples to apples you need to compare two coils with the same mass... period... and to be fair in other terms of performance wind height should also be the same... I can get aluminum & copper round in a wide variety of gauges as well as flat, and edge wound, at any wind height... so there is no reason why a direct comparison shouldn't be made...

As far as copper taking longer to cool, try looking up the thermal conductivity... :suicide:

Kyle_Keating
11-09-2010, 09:34 PM
if both coils are = then the alum will be louder. the copper will handle the power betterfordaily though...

SPLsens is based on BL, Re, Mms and Cone area. The difference between Cu and Al is 3 times the mass but only 2/3rs the Resistance. There is a thermal conductivity difference to in favor of copper, but we'll ignore large signal differences for now.

There is no way to tell is Cu will be more or less sensitive than than AL because the Mms also depends on the rest of the soft-parts. For example, lets say the coil only made up 1% of that mass - In that case copper would out perform aluminum on all fronts. Now lets say it made up 99% of the moving mass - AL would be the clear choice.

CHUCKmfnNORRIS
11-09-2010, 09:59 PM
are you all still arguing on what metal cools faster?

SPLaudio
11-09-2010, 10:26 PM
nobody is arguing this is the sub section and we can have more indepth conversations.

its better that is x louder than y,lol.

sorry if it bores you guys...

SPLaudio
11-09-2010, 10:34 PM
if there is people more knowledgable than you about something always listen, im always open to being skooled...

CHUCKmfnNORRIS
11-09-2010, 10:39 PM
yeah i know, i've been reading all the posts and have learned a lot after what i thought was a quick easy answer.

hispls
11-09-2010, 10:50 PM
The thermal conductivity of copper is considerably greater then aluminum... :fyi:


This really isn't rocket science.. with one aluminum and one copper coil of equal mass, wind height, adhesive, former, ect, the copper coil will handle slightly more power.. additionally, because the windings of the copper coil will be considerably smaller you can use a tighter gap for increased BL...


The only reason to use aluminum, as far as I am concearned, is to save money.... (same as with house wiring)

Would there be significant difference in coils of equal mass and height as far as gauge of the coil wire and thermal power handling?

sundownz
11-10-2010, 09:09 AM
Yes, there would be a difference in mass if the coils were even somewhat similar (if they were of equal mass they wouldn't even be close)... example :

4-layer copper / 63.5mm former / 45mm WW / 7.01 ohm = 0.48mm diameter wire / ~113 grams / 67.74 mm OD
4-layer CCAW / 63.5mm former / 45mm WW / 7.06 ohm = 0.54mm diameter wire / ~40 grams / 68.19 mm OD

If we try to make them of equal mass the CCAW coil would need to be about 97mm long given a DCR close to the above (7.17 in this case).

-----

Using just a sample driver with 110-grams non coil mass -- top plate gap adjusted to be equal from CCAW to the Copper :

COPPER:
Motor Force Factor = 109
Total MMS = 223 grams
Ratio = 0.488

CCAW:
Motor Force Factor = 84
Total MMS = 149 grams
Ratio = 0.563

In this scenario the CCAW would be about 0.5 dB louder assuming FS isn't having a big impact on the score in your setup.

But to examine Kyle's point further about coil mass as a percentage of total mass lets make the non-coil mass 250 grams :

COPPER:
Motor Force Factor = 109
Total MMS = 363 grams
Ratio = 0.300

CCAW:
Motor Force Factor = 84
Total MMS = 289 grams
Ratio = 0.290

Note that the CCAW coil now has a worse ratio.

Moral of the story ? It depends on what you goal is in the design process... copper, aluminum, and CCAW all have their place based on application.

sundownz
11-10-2010, 09:15 AM
I miss this type of discussion -- we should have them more often.

denim
11-10-2010, 11:36 AM
I miss this type of discussion -- we should have them more often.

Might be the best technical topic here in a while. :)

VWBobby
11-11-2010, 05:06 PM
Indeed. I've only recently been visiting, but there definitely needs to be more discussion like this and a lot less bickering.

Haunz
11-12-2010, 12:55 AM
Yes, there would be a difference in mass if the coils were even somewhat similar (if they were of equal mass they wouldn't even be close)... example :

4-layer copper / 63.5mm former / 45mm WW / 7.01 ohm = 0.48mm diameter wire / ~113 grams / 67.74 mm OD
4-layer CCAW / 63.5mm former / 45mm WW / 7.06 ohm = 0.54mm diameter wire / ~40 grams / 68.19 mm OD

If we try to make them of equal mass the CCAW coil would need to be about 97mm long given a DCR close to the above (7.17 in this case).



We obviously can't make two coils using different materials the same.. so this time try to forget about DCR... The aspect I bring to the table is based on performance considering identical mass and wattage (and not DCR per say)... so lets try an aluminum coil with a corresponding larger dia. wire and overall O.D. for the same mass and wind height and see which handles more power and has the better sensitivity...


I must admit that aluminum has some advantages for SPL burping being light weight, and with it's gram for gram heat capacity.. but copper is clearly the better conductor, and is much more suited to playing music / overall abuse....

SPLaudio
11-12-2010, 07:17 AM
nobody is going to disagree copper is far better the conducter.

now i hear what ur saying so it would be like a 4 layer copper against a 12layer alum to get the same weight.

the alum will win! esp cause by the time you have a 12 layer alum coil to get the mass up the gap is gonna be pretty big on that motor and the copper will be too skinny of a coil and bl will fall.
when building a sub you normally keep inmind of what coil your gonna use and build the gap for it.

i am a spl guy so i like the tight gaped subs but gapping is a whole other topic..


for a daily beater sub i choose copper for a 3sec burp sub i want alum...

sundownz
11-12-2010, 08:24 AM
We obviously can't make two coils using different materials the same.. so this time try to forget about DCR... The aspect I bring to the table is based on performance considering identical mass and wattage (and not DCR per say)... so lets try an aluminum coil with a corresponding larger dia. wire and overall O.D. for the same mass and wind height and see which handles more power and has the better sensitivity...

I must admit that aluminum has some advantages for SPL burping being light weight, and with it's gram for gram heat capacity.. but copper is clearly the better conductor, and is much more suited to playing music / overall abuse....

Even for your alternate example... lets examine:

4-layer copper / 63.5mm former / 45mm WW / 7.01 ohm = 0.48mm diameter wire / ~113 grams / 67.74 mm OD

Now using the largest typically available CCAW wire :

4-layer CCAW / 63.5mm former / 45mm WW / 1.46 ohm = 0.90mm diameter wire / 66.8 grams / 70.88 mm OD

The coil is vastly different so not even comparable at all... to get somewhat comparable in mass at a given WW you would have to get into 8-layer or more flat aluminum coils (like 12-layers).

I like a good copper coil as well -- I use them in my SA series and Z v.2 series. It really is going to come down to the overall design -- one material isn't simply superior flat out, IMO. I use both materials in design based on my goals.

Haunz
11-14-2010, 08:11 PM
4-layer copper / 63.5mm former / 45mm WW / 7.01 ohm = 0.48mm diameter wire / ~113 grams / 67.74 mm OD

4-layer CCAW / 63.5mm former / 45mm WW / 1.46 ohm = 0.90mm diameter wire / 66.8 grams / 70.88 mm OD

The coil is vastly different so not even comparable at all... to get somewhat comparable in mass at a given WW you would have to get into 8-layer or more flat aluminum coils (like 12-layers).

one material isn't simply superior flat out, IMO. I use both materials in design based on my goals.


Thinner dia. then .48mm copper wire is certainly available, so for a direct comparison with mass in mind, you still elude my point... I wholeheartedly agree that one material is not flat out superior to the other.. as with anything there are trades offs.. but I will always hold the view that copper is the better metal to use for a voice coil... (and I'd use silver if I could)


nobody is going to disagree copper is far better the conducter.

now i hear what ur saying so it would be like a 4 layer copper against a 12layer alum to get the same weight.

the alum will win! esp cause by the time you have a 12 layer alum coil to get the mass up the gap is gonna be pretty big on that motor and the copper will be too skinny of a coil and bl will fall.
when building a sub you normally keep inmind of what coil your gonna use and build the gap for it.

i am a spl guy so i like the tight gaped subs but gapping is a whole other topic..


for a daily beater sub i choose copper for a 3sec burp sub i want alum...

I might agree for the 3sec burp...
Just keep in mind the 4layer copper would also require a much, much, smaller gap then a 12layer aluminum...

SPLaudio
11-14-2010, 09:42 PM
spl subs are ment for the loud 3 secs...

papermaker
11-15-2010, 06:46 PM
It's hard to say as each woofer will have different results in nearly every app..
I know this for a fact though mass in spl isn't a huge deal because you can use huge gaps and we have retarded strong Motors as well as super stiff spiders..

The biggest factor is power compression and believe it or not the proper dampening for a given input cabin and box...
The woofer has t complement the installation..

Kyle_Keating
11-15-2010, 08:26 PM
Glue a 1kg weight onto your cone and re-burp your driver. You're going lose dB in the double digits. A smaller increase in mass may be less significate, but clearly there is a linear trend to increasing mass and losing dB. One of the best ways to fight power compression is to decrease the mass. Of course at some point you decrease it so much that the driver can become suspect to damage because its weaker due to lighter/thinner parts.

iLL Ridge
11-15-2010, 09:08 PM
Good reading