Fi Audio 18BL warranty issue - failed after an hour of use

[keep_hope_alive Premium Member]

Coil does not need to look black to have failed from heat, though almost always you'll get some smell before they fail from over-heating. Consider smaller drivers move more on the same power and cool better.

great insight. yep, there was a smell right before failure, but it was too late at that point. remember this isn't my vehicle and while i was with the owner he did have time to play it without me, but he didn't go past the volume I told him not to. Clipping wasn't a concern.

i'm starting to wonder if the box caused the cone to "stall" at some frequency and that led to overheating the coil. that makes the most sense. i will run some more tests to verify and change the box design if necessary. i dislike the port placement as-is anyway.

thanks for the responses everyone. I think we kept this thread from getting out of hand, a rarity in this day and age. Good job not acting like e-thugs!!!

 

[hispls 5,000+ posts]

RLDriverv2 hook me up then! i will spend couple k 1st order...

Group buy?

 

[keep_hope_alive Premium Member]

My thoughts exactly, and a worthy topic. One of the reasons I don't like 18" woofers, really. Side by side a smaller cone will move more and cool better. I find smaller drivers hold thermal power noticeably better than larger (assuming same motor, coils, and suspension).

excellent topic. we have a 12 in there now and it's doing just fine. i'm not overly impressed with the cooling on the BL. it's pretty basic and old-school. nothing like the cooling on say, a ML3000.

sub in there now running fine (several years old)

how i got it to mount using the holes for the 18:

 

[LosIsATool 5,000+ posts]

excellent topic. we have a 12 in there now and it's doing just fine. i'm not overly impressed with the cooling on the BL. it's pretty basic and old-school. nothing like the cooling on say, a ML3000.
sub in there now running fine (several years old)

how i got it to mount using the holes for the 18:

Is that a mayhem? I buddy's got 4 12s still kicking

 

[hispls 5,000+ posts]

excellent topic. we have a 12 in there now and it's doing just fine. i'm not overly impressed with the cooling on the BL. it's pretty basic and old-school. nothing like the cooling on say, a ML3000.
sub in there now running fine (several years old)

8 layer coil on that Alphasonic? That would make a difference. From what I've been told by reliable sources the fancy "cooling" options you see don't really make a big difference in real world applications (some, but not dramatic). They look impressive but at the end of the day the amount of metal in the coil seems to be the deciding factor when it comes to how much heat it'll take before coming apart.

 

[mlstrass 5,000+ posts]

great insight. yep, there was a smell right before failure, but it was too late at that point. remember this isn't my vehicle and while i was with the owner he did have time to play it without me, but he didn't go past the volume I told him not to. Clipping wasn't a concern.
i'm starting to wonder if the box caused the cone to "stall" at some frequency and that led to overheating the coil. that makes the most sense. i will run some more tests to verify and change the box design if necessary. i dislike the port placement as-is anyway.

thanks for the responses everyone. I think we kept this thread from getting out of hand, a rarity in this day and age. Good job not acting like e-thugs!!!

I would say more his choice of music vs box design. Might have played a lot of low stuff to really push current thru the coil, then higher stuff which did nothing to help cool it down. Tuning/box size might help some, but it's pretty hard to "idiot" proof a set up that runs way over RMS.

I say overzealous/inexperienced user who didn't read the signs....that wonderful burning coil smell...and didn't back off in time. Live and learn as most on this forum have done that once or twice.

 

[sundownz Pro Seller]

8 layer coil on that Alphasonic? That would make a difference. From what I've been told by reliable sources the fancy "cooling" options you see don't really make a big difference in real world applications (some, but not dramatic). They look impressive but at the end of the day the amount of metal in the coil seems to be the deciding factor when it comes to how much heat it'll take before coming apart.

Alot of that depends on how the cooling works vs. cone displacement as well -- many methods rely on alot of movement to pump air; others will work with much less cone movement and continue to increase in efficiency as movement increases (such as what we have on the SA). I've personally experimented with dozens of different venting methods / airflow patterns over the years -- and they vary alot in when they work the best; so I can see why the topic is so hotly debated.

I spoke with the engineer from Alpine at CES (great guy by the way... very smart) about their method of testing the new Type-R woofer thermally vs. when I tested it at 60 Hz only (he saw my test) -- I killed it FAST on 60 Hz. Their method plays a broad spectrum starting at ~30 hz --- 30 Hz will have 4x the cone movement for a given output level so it's pretty dramatic. The driver meets and/or exceeds their power spec when tested this way -- my 60 hz test is not as indicative of what end-users do to a woofer but I consider it a "worst case" test so I like to check my drivers with it.

The same test on the SA; which has a nearly identical coil in terms of size, wire material, former material, AND adhesive temp rating (it is actually slightly smaller by 0.1" coil former ID than the Type-R as they use a 2.6" coil); the sub played for 9+ minutes at 60 Hz (I've posted a few videos of various tests we've done this way). I've tuned the SA woofers venting several times over the years -- and in most applications can match or exceed a 3" coil that does not use similar cooling tricks thermally. End-user results will back this up if you take a look at what people have done with these drivers in terms of power applied //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Adding more surface area / material is always an easier way to gain thermal performance -- very predictable result and gains thermal performance at any level of travel. There is also something to be said for how quickly the heating occurs -- a bigger coil will be more resilient to the power being applied very quickly.

Anyway -- that is all a little off topic but a fun conversation to have //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[hispls 5,000+ posts]

Alot of that depends on how the cooling works vs. cone displacement as well -- many methods rely on alot of movement to pump air; others will work with much less cone movement and continue to increase in efficiency as movement increases (such as what we have on the SA). I've personally experimented with dozens of different venting methods / airflow patterns over the years -- and they vary alot in when they work the best; so I can see why the topic is so hotly debated.
I spoke with the engineer from Alpine at CES (great guy by the way... very smart) about their method of testing the new Type-R woofer thermally vs. when I tested it at 60 Hz only (he saw my test) -- I killed it FAST on 60 Hz. Their method plays a broad spectrum starting at ~30 hz --- 30 Hz will have 4x the cone movement for a given output level so it's pretty dramatic. The driver meets and/or exceeds their power spec when tested this way -- my 60 hz test is not as indicative of what end-users do to a woofer but I consider it a "worst case" test so I like to check my drivers with it.

The same test on the SA; which has a nearly identical coil in terms of size, wire material, former material, AND adhesive temp rating (it is actually slightly smaller by 0.1" coil former ID than the Type-R as they use a 2.6" coil); the sub played for 9+ minutes at 60 Hz (I've posted a few videos of various tests we've done this way). I've tuned the SA woofers venting several times over the years -- and in most applications can match or exceed a 3" coil that does not use similar cooling tricks thermally. End-user results will back this up if you take a look at what people have done with these drivers in terms of power applied //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

Adding more surface area / material is always an easier way to gain thermal performance -- very predictable result and gains thermal performance at any level of travel. There is also something to be said for how quickly the heating occurs -- a bigger coil will be more resilient to the power being applied very quickly.

Anyway -- that is all a little off topic but a fun conversation to have //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

I can think of quite a bit of music that rides hard @ 50-60hz range AND I would go as far as to say that people tuning in the low 30's may push things a little more at that range to get the output they're used to around tuning. I like the 50hz sine wave as a true "continuous" power rating. I believe this is the standard used by Eminence.

Anyway, if you stop back, care to share what percentage more power any special cooling features will allow over long term? I would hazard to guess that it would translate into inaudible gains with two drivers side by side pushed to limits. Obviously it's nice to make a woofer more idiot proof from a manufacturing standpoint, but as far as end users thinking that every day one will be louder than the other merely because they can throw an extra 150W at a 1500W driver I wouldn't want to get people's hopes up. There's far more things you could do to make a speaker perform better at that stage than throwing 10% more power at it.

 

[denim 5,000+ posts]

excellent topic. we have a 12 in there now and it's doing just fine. i'm not overly impressed with the cooling on the BL. it's pretty basic and old-school. nothing like the cooling on say, a ML3000.
sub in there now running fine (several years old)

If you saw inside the BL motor, you would think other wise. Pole vents and holes in the top or bottom plate, do not always equal superior cooling. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[keep_hope_alive Premium Member]

If you saw inside the BL motor, you would think other wise. Pole vents and holes in the top or bottom plate, do not always equal superior cooling. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

gotcha. i guess a thermal failure out of the gate gives me pause to give them credit for thermal management.

got images of the motor? there aren't any vents on the magnet itself, so all venting is between the spider and plate?

 

[Flastrongman 10+ year member]

I would have really liked to have seen pics of the coil after it was cut out.

 

[SPLaudio 5,000+ posts]

cooling wont help much if ur clipping hard fyi peeps.

 

[keep_hope_alive Premium Member]

Agreed, which is why I prevent it. Pretty easy to do.

 

[mlstrass 5,000+ posts]

Agreed, which is why I prevent it. Pretty easy to do.

Assuming his electrical was able to keep up for his 30-40 minute playing session. What was clean when you set it might not have been when voltage dropped bad, if it did...

 

[Joseph7195 10+ year member]

Lots of good info in this thread, I am glad the nooby troll was squashed before all was lost.