Is it burning off excess glue or damaging voice coil?

[truckramrod 10+ year member]

I have a RF Power 15 motor with a 4" voice coil that I had reconed by tim roy in the spring.

Ever since I installed it months ago, I've never really cranked it, since I wanted to break it in and it has fairly good output due to the ported box.

Anyways I adjusted the gain, low pass filter and subsonic filter, now it is loud and clear with no distortion. However after a few minutes of hard playing (135db or more). I have a burning smell and I don't know if its the excess glue burning off the voice coil or voice coil overheating, when this happens the dustcap gets pretty hot to the touch. It smells like burnt popcorn or rotting food or burnt wax paper or something.

I dont' think I'm overpowering the woofer since the the cone movement isn't extreme.(I don't think the woofer is reaching its mechanical limits.)

Any opinions or suggestions would be really appreciated!

As far as power it has a single 1.2 ohm coil and its being pushed by the amp in my sig. The original sub was rated at 600wrms and Tim Roy suggested 1500wrms for this woofer. I'm giving it 1000-1100 watts, I don't want to damage it!

I wonder if I need to go from a 2.25 cube box with a 38 hz tuning to a 3-3.5 cube box with 32-33 tuning.

Any opinions or ideas are appreciated!

Click to read more...

 

[truckramrod 10+ year member]

can anyone describe the smell of burning coils and just burning off excess glue?

 

[Trixter 10+ year member]

well, if you are over powering it, putting it in a bigger box and lowering the tuning definitely will not help.

i would talk to tim and ask his opinion...tell him the box design and the power your feeding it. if he says that its good, hopefully he'll back his work if something goes wrong with it.

chances are it is the glue...hell my gen 1 brahma 15" still smells like that sometimes...

 

[truckramrod 10+ year member]

I agreee, but if anything it is reaching its thermal limit, not it's mechanical limit, so a different box design may get me more output with less power.

The RF spec for a ported box is 2.75 cubes tuned to 40hz and Tim says the recone should be somewhat close in parameters, but maybe it would like more volume and lower tuning.

Tim replied back that, it sounds like I may be sending dc current to the sub, at high volumes. I think I'm going to borrow a coworkers Oscilloscope to verify I have a clean signal at those volumes.

 

[sundownz Pro Seller]

With a 4" coil its going to be hard to damage this woofer thermally - so you are just smelling hot adhesives. Pretty normal on high powered woofers.