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

[SPLaudio]

bl uses a fatter 4 layer 3.250od alum coil with bout 2.250 ww.

i wanna see pix of the sub parts before i pass judgement.

Fi's fail most the time for ripped spiders or the leads damaged from being between the spiders.

[mrogowski]

Whatever it is its bad QC. I guess they needed something else since the spiders stopped catching on fire

Bad QC from whom - the company who assembled the product or the company who wound the voice coil?

I've reconed several subs with unwound coils for diff people. 8 out of 10 times it's clipping and the coil, or what's left is black. Other few times it's been thermal/over powering and glue heats up. These subs were seeing 2-3x RMS and playing music for extended periods.

My one question: wast most of the music/burps around 50Hz or so? If so did you notice very little excursion out of the sub as that will create a lot more heat with little to no movement to cool the sub.

Could just be a case of too much power/too little excursion and the sub overheated and let go. BL's aren't exactly killer strong subs...

Good point.

In fairness, lead wires catching on fire seems like a supplier issue. As somebody who has worked in a quality engineering position before, let me tell you that lots of problems like these are completely out of manufacturer control. Yet, nobody understands the concept of process flow and how many different companies are involved in a finished product. So many people over-simplify the process to rationalize pinning the tail on manufacturer.

While it could be Fi's mistake that tinsels were catching on fire, the build house could have compromised the leads, or the raw materials supplier might have made defective wire/sheathing. I'm sure that it was thoroughly investigated, especially considering the safety issues involved with the malfunction.

Indeed.

[keep_hope_alive]

pics are on a thumbdrive at work. i will post them once i get them off the drive.

Fi and I went back and forth. They agreed to pay for the recone if I pay for shipping back to myself. I agreed. Out $120 but better than nothing.

To explain why the coils measure 1 ohm and 2 ohm:

Yes, the coil is a quad 2 layer with pairs of coils wound in parallel. This boils down to 4 1.4 DCR coils with pairs wired in parallel at the coil winders to yield the proper packing factor for our needs and a dual .7 Ohm (1 Ohm nominal coil). One of the coils came apart when it unwound and broke. This opened up half of the coil. Each is tested before leaving to ensure proper function of the speaker as well as DCR.
If the coil left here with a 1.4 and .7 coil, there still is no way of wiring it that would draw more power or be more harmful to the coil than a correct D.7. I have seen the swelling and coil delamination before and can reproduce it. It stems from a coil that is wired out of phase and provides little to no movement and all heat build up.

The terminals are placed correctly (with respect to color and phase) and it is impossible to wind the coil out of phase at the factory. Leads were not crossed under the cap (which would be very difficult for a builder to do).
We can not find any specific inherent factory problem with the build of the sub that would allow this to occur.

I will recone the sub free of charge if you agree to pay for the return shipping.

I am satisfied with the offer.


To the following, i replied explaining that the sub only saw music for 30-40 minutes and 30 second sweeps of sine waves. I don't expect an hour of use to cause the sub to look completely different:

The tech log book on your speaker indicated that the suspension and spiders were as stiff as a new speaker and if it did move it was very little. The log book also states that the coils were wired out of phase of each other which swelled the wire off of the former causing the coil to unwind and fall off in the gap. If it were wired properly the suspension would have shown wear and it would be broken in some as well as the tinsels would have been moved a bit from their factory location, but according to the notes is very close to the same suspension compliance as a brand new sub and the tinsel leads show no signs of any significant movement.

It hasn't been addressed how "out of phase" coils could still have significant output, because it wouldn't. In the end, they blame me but agree to fix the sub. I know the coils were in phase, but settling for paying shipping both ways.

We are on week 4.

[LosIsATool]

So they are saying the coils where out of phase but still making you come out of pocket after waiting 4 weeks? You're going to be pretty loud where the coils are in phase. That's good news

[keep_hope_alive]

So they are saying the coils where out of phase but still making you come out of pocket after waiting 4 weeks? You're going to be pretty loud where the coils are in phase. That's good news

coils were in phase. no way they weren't, if they weren't it would have been obvious immediately. the sub was failing before the measurement and the measurement wasn't at full rip.

i agree, a properly built sub will be great!

[LosIsATool]

I still don't understand if they are saying it was fualty from the start why would you have to come out of pocket for anything? In phase or not they said it was out. That's a defective coil is it not? That's a manufacturer defect. That's a full warranty.

[TheUnderFighter]

I still don't understand if they are saying it was fualty from the start why would you have to come out of pocket for anything? In phase or not they said it was out. That's a defective coil is it not? That's a manufacturer defect. That's a full warranty.

No, what they are doing is avoiding any blame. They're saying HE wired it out of phase. However, as anyone that's done this will know, wiring a sub out of phase produces little to no output. However, Richard experienced impressive output for the short while it lasted, which proves right off the bat that it was not wired out of phase. I don't know why it is SO hard for Fi to imagine that of ALLLLL the subwoofers they put out, just one might have had a defective coil? That doesn't mean Fi did anything wrong, maybe it was bad coming straight from Precision.

[SPLaudio]

****** companys put the blame on the customer without showing real facts!

[keep_hope_alive]

I am taking what I can get. I feel it should be a full warranty claim but they won't. I either throw away $460 or spend another $60 and have something to show for it.

In the future I will not buy subs from online retailers. My local shop would have exchanged over the counter.

[keep_hope_alive]

[LosIsATool]

I am taking what I can get. I feel it should be a full warranty claim but they won't. I either throw away $460 or spend another $60 and have something to show for it.

In the future I will not buy subs from online retailers. My local shop would have exchanged over the counter.

A local shop wouldnt do it for everybody though, at least the ones I know of. If they know you and you've spent money with them they tend to not give a hard time. So many shops take advantage of people though. I got tired of sending ups across the US I'll stick with my shop but I do know the owner and he does take care of me. not everybody has that.

[SPLaudio]

looks like they went back to floating leads too many failures with the leads woven in the spiders.

dont think that bout all online places i take care of my customers even if i gotta reach in my own pocket and call it a loss.

if the coil isnt burnt it should be under warrenty...

[d77543020]

online dealers need to realize they will live and die by word of mouth and they have now lost keep_hope_alive as a customer over such a small issue, and many others reading this will also think twice before ordering anything from fi, i personally never bought anything from them only because i seen way to many post on how hard it was to get in contact with them and now i see how they deal with customers with problems

[hispls]

Not to fi they arent ...the customer yes

There is absolutely no way in hell they're reconeing a speaker for 10$ If you know a way to do that you will get rich quickly selling recones for 50$ and undercutting everyone else by half.

trust me, it costs fi more than $10 in parts for a recone. just the coil is about $10

If you buy 100 coils the price of a 4 layer 3" is close to 30$ , I can't imagine them dropping down to 10$ even if you bought 10,000 at a whack. Really I doubt you could get garbage quality Chinese coils for 10$

i am curious if anyone else has had a coil let loose from the former, and what the circumstances were/are.

I have twice (and I break a lot of woofers), both 18" woofers, 5KW and up pushing hard, and they stunk bad before they let go.

Sounds like a lemon to me ....ive seen lots of spider issues but no coils lettig loose..esp on that power..and i kno this is far from ur first rodeo so id say they are just jewing u around ....every company no matter how reputable has issues like this..just ***** fi chose to go about it this way

Maybe Fi is backed up and subs are getting rushed. If you set with a DMM for 1000 per coil I doubt you where getting over RMS. to me it sounds like they skimped on assembly.

If this is manufacturer defect it is in the coil and nothing Fi did or did not do. Anything over 1200W continuous power will make a 3" 4 layer coil fail, Once you cross that threshold of where it can't dissipate heat fast enough they will overheat and fail quickly, exponentially faster as you increase power or decrease cone movement (cooling)

no, id rather not "trust you" coils bought from precision, when bought in the bulk fi buys in are about 3-4 dollars each.

Calling bullshit on this without some sort of proof.

how many have seen a coil unwind and what were the circumstances? how many have had a brand new sub fail within hours and why was it (besides pure SPL destruction purposes)?

obviously, to get the coils to unwind they need to be hot enough for the glue to let loose. the amps never went into protect and the coils aren't shorted. they weren't ran long enough to overheat from extended use (only pushed a few minutes at a time). if they coils were mis-matched, one coil would heat up more than the other. that is the only concrete evidence we have right now, mismatched coil DCR.

I've only ever had coils go slinky from gross abuse. I've had some subs break within a short time after building them, but that's mechanical from either me being abusive or trying to skimp on glue. Of course you would know if it was a glue issue.

wast most of the music/burps around 50Hz or so? If so did you notice very little excursion out of the sub as that will create a lot more heat with little to no movement to cool the sub.

Could just be a case of too much power/too little excursion and the sub overheated and let go. BL's aren't exactly killer strong subs...

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).

good questions. music covered a wide range and the tones weren't that long in duration. clipping didn't happen, i'm sure of that. scopes don't lie. and nothing was black, coil looks new just unwound.

there was plenty of cone excursion with initial testing around 50Hz, and i agree that the coil would heat up if the cone wasn't moving to create airflow to cool the coil.

maybe i need to take a closer look at cone behavior in the box and if the cone seems to "stall" around certain frequencies. even still, i would expect it would take longer, since the music was constantly changing and the tones were higher.

the intent is a daily system, not an SPL monster. Box is tuned around 28Hz. The sub in there now does just fine.

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.

If they are using 8-layer flat wind coils from Precision in Florida... the coil itself is 2.5-3x that much. A 4-layer round is still 1.5x that much if it's fairly long.

Either way -- they do use Precision coils at Fi; I am just not sure what type in that model driver -- Precision makes some of the best coils available and a coil that is simply defective is almost unheard of as far as a coil just sliding off of a former.

So that would leave us to figure out how the coil got so hot so quickly.

When you used the scope did you test it on the music signal as well in case the level was different ? The amps made in the style of the Massive Nano (similar design to Audiopipe) make a VERY weird and jagged wave with spikes when clipped on the ones I've tested. We did some testing here a few weeks and when we pushed amps of that design into clipping the coil smelled rapidly; same clamped power on a Korean Class-D (which clips very smooth and flattens out up top) no such smell.

Either way; good luck resolving your issues

This is the most accurate explanation of cost of coils and most likely explanation for cause of failure. I wouldn't rule out that Precision made a dud coil, but this seems most likely.

---------- Post added at 10:36 AM ---------- Previous post was at 10:35 AM ----------

:roflbowdown: @ people paying more than 3-4 for a precision 3" coil. You guys are high.

I guess Jacob doesn't buy enough of them to know what the real price is right? Please tell me how I can get my coils for 3-4$.

[SPLaudio]

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