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Discussion Starter #1
I recently sold a subwoofer to a guy from Craigslist. Met up with the guy, helped wire and install the sub. He had blown his Polk DB sub and was replacing it. Since he didn't need the sub any longer he passed it on to me. He told me it was blown, then as he was leaving said that it only worked when he pushed down on the cone. I didn't believe him but he was right, it only works when the cone is pushed down to about half the xmax.

I popped off the dust cap and don't see anything that seems wrong with the vc. I think there might be a bad connection in the tinsel leads going to the vc perhaps???

Any ideas?
 

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First step: Take a multimeter and measure across the terminals and see how the results differ with the cone at rest vs pushed in. If it's an open circuit at rest and normal when pushed down then perhaps it is a bad connection like that. If it's shorted then... that's worse.
 

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it is scratchy at all when you push on it? possible bent former?
 

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I've had that be tinsels, some the tinsels even looked just fine but could move one and it would work. Usually at the terminal or at the cone.
 

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bad voice coil, there is a break in it and when you push down it makes contact. it most likely arcs out so it gets stuck together and it will play for a few seconds.
 

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Discussion Starter #6
it is scratchy at all when you push on it? possible bent former?
No, it doesn't rub or anything when pushed in. Feels fine.

bad voice coil, there is a break in it and when you push down it makes contact. it most likely arcs out so it gets stuck together and it will play for a few seconds.
Hmm, that makes sense.

I also have a pair of Polk DXi's that were handed down to me. Both are DVC's and have blown coils. What is it with these people blowing out Polk subs?? They're rated at 360 rms just like the DB sub.
 

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I recently sold a subwoofer to a guy from Craigslist. Met up with the guy, helped wire and install the sub. He had blown his Polk DB sub and was replacing it. Since he didn't need the sub any longer he passed it on to me. He told me it was blown, then as he was leaving said that it only worked when he pushed down on the cone. I didn't believe him but he was right, it only works when the cone is pushed down to about half the xmax.

I popped off the dust cap and don't see anything that seems wrong with the vc. I think there might be a bad connection in the tinsel leads going to the vc perhaps???

Any ideas?
I'd say it could be the tinsel connection is either loose or broken off from the terminal's. I had this problem once with some P-Miller Bazookas, the tinsel wire came off from the terminal, a little solder and wa-lla.

If the wire/tensils look good then hook a multimeter and see if it has any resistance, move the cone (pushing it and pulling it up) to see if the resistance changes and if there is any break in the resistance.
 

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Discussion Starter #8
Won't have my meter till tomorrow. My brother is using it on a sensor on his car. What should I be looking for once I get the meter on it???
 

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Won't have my meter till tomorrow. My brother is using it on a sensor on his car. What should I be looking for once I get the meter on it???
Usually a resistance of 3.6-4ohms if its a 4-ohm woofer or 1.5-2ohms if its a 2-ohm woofer. But you should get a reading right away without touching the cone. Once you have a reading you can blow on the cone and see if the reading changes, then you can push or pull to see if the resistance changes (it usally jumps up pretty high but thats normal).

I have a fluke 111 and its pretty neat because it has range/min&max setting and if there is a short while moving the cone it will beep. Otherwise you will have to look for a "OL" open circuit display on the meter.
 

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bad voice coil, there is a break in it and when you push down it makes contact. it most likely arcs out so it gets stuck together and it will play for a few seconds.
X2...I agree with your opinion...I've seen this happen a few times over the years...I think you need to throw it in the trash and move on:p
 

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First of all; I'm REALLLLY sorry for bumping a 6 year old thread, lol! But since the thread is about my problem too, or similar - here it goes.

I got a Soundstream tarantula t4 12" sub (second hand) and it's connected it series. The sub is dual 1ohm vc, but when I hook up a multimeter to it, it shows 4.1ohm. Was reading a few until a few hours ago.. I bumped some tunes (loudly) and it stopped working, only works when I push the cone in.

Worked fine for about 3 weeks and now this happens :(

I quickly checked the tinsel leads and while testing it did't work, so basicly it only works when pushed down.

I'll take a closer look tomorrow as I'm currently not able to check, but I'm going on a wild guess and say that the coils are fu**ed? :(

Also, wasn't overpowered (ran by renegade ren1800 - set at 500ish W bridged mode), atleast for the time spent in my possesion.
 

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The extra resistance could be from the meter leads and that's why it's reading high. Just something to check.

As for you problem, The tinsel leads go into an area under the dust cap Where they are soldered to the leads from the coil. This area is called the triple joint and is a common place for wiring problems. To get to it you'll have to get the dustcap off, but you can buy a new dustcap and glue it in as long as you don't damage the cone. Obviously You should check the tinsel leads first.
 

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A lot of people clip the hell out of their sub amps and dont know it. Its much harder to hear on subs. Most subs are not meant to "beat". They are simply made to play the lower freqs. Unfortunalty a lot of people insist on playing them 10 to 20 times louder than the rest if their system.
, meaning around 20 db louder than they were designed to play. You cant get that loud without clipping with that low of power. At 120db a car has decent bass balanced with most systems. At 120db not much in the car shakes and there isnt a lot of pressure on your ears.
If it takes 500w to hit that 120 it takes 1000 to hit 123 and 2000 to hit 126. Most guys are running nowhere near enough clean power for the ouput they want much less than having any headroom at all. So they clip the hell out of the sub amp , because they cant hear it clipping and think everything is ok. Boom blown subs.
Getting high pressure "booming" with music takes subs that are built for that purpose and a **** ton of power considering subs are usually not sensitive at all. 600w produces an output cleanly of around 110 db on an 85db sensitive sub. Maybe add another 10db for cabin gain. So we are at 120 now. To hit 123 we need 1200w of power. To hit 126 we need 2400w of power. I see at least 10 blown subs a week in a pile every saturday and the reason is almost always the same. Kids want loud bass and have no idea what it takes to it right. Asking a 500 watt amp to make 140db of bass in a average system is begging for the clipped system to cook subs.
 

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I'm aware of everything you said, but i set the sub gain at much lower wattage (500ish - the amp max is 700-750w rms bridged) and the sub is 900w rms.

I'm currently running 4ch only off of headunit so I didn't push the sub too far :|
 

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I'm aware of everything you said, but i set the sub gain at much lower wattage (500ish - the amp max is 700-750w rms bridged) and the sub is 900w rms.

I'm currently running 4ch only off of headunit so I didn't push the sub too far :|
Was stuff in your car shaking? At casual listening levels in a balanced system youd barely see movement in your rear view and have a slight felt sensation in your seat. Zero pressure on your ears. Asking 500w to do anymore than that on a 900w rms sub and i can almost gurantee you were clipping.
Anyway thats all irrelevant. If it isnt a tensil your sub is done. Look for a recone kit or a new sub.
 

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'Olla again. I've checked the sub and it's been worked on before. Here are a few pics.

As you can see on the pictures the aluminium where the voice coil is at isn't in good shape, but when i turn the sub sideways there's no scratching. The tinsel leads were already broke and in "fixed" in an idiotic way. How do I get to the voice coil? Is there a way to melt the silicone (i think it's silicone, it's very hard to touch but doesn't look like glue.)? I was thinking of getting some new tensil leads and soldering them directly from the coil to terminals.

This cleans up the issue I have with coil resistance as the voice coil is probably ghetto af.

Also, what's the price on recone kits and where to find it? Or a replacement one that's suitable for this sub.
 

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Me again. The desoldering braid took a beating and broke. Does anyone know what kind of tinsel lead wire I should get, thickness wise? Or, if anyone has an idea on where to find a recone kit for my sub (Soundstream t4 12") Thanks!
 

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You won't need anything large for that sub. Here's some for $6 shipped:

1000 Watt Braided Speaker Tinsel Lead Wire .044" Dia. - 6" pcs x 2 | eBay

As for a recone - the cost vs the value of the sub might make it prohibitive, but fixmyspeaker.com would be the easiest way to get one.
Thanks alot for the quick response!
Haa - 30$ shipping to Croatia ;P Also, it states 1000w peak (this one is 900wrms, peak "2300w").
I'll try to get someone within that thickness, or a little thicker. And yeah I suppose recone is probably too expensive taking the general state of the woofer in consideration :/ It's sad cause I reaaally like it, bumps like hell. First "better" sub I've had, i recently had a 10" pioneer 350wrms and a pyle 600wrms (currently using that one since the SS is doomed).
 
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