Jim85IROC

iTrader: (2)

Equipment: Component speakers up front, 2 subs in the back, a small 4 channel pheonix gold amp for all of them. Head unit is an old school Excelon PS907 with absolutely NO filtering capabilities at all. I have 1 set of RCAs running to the amp, where the subs are low-passed and the components are high-passed at 80hz.

Initially the front speakers were CDTs. Once winter arrived, one of the midbasses began to work intermittantly. Shortly after, the 2nd did the same thing. I always considered this odd that both woofers would suffer the same sort of failure like that. I suspected that cold solders in the crossover were to blame, but resoldering the entire board made no improvement. Finally after one of the 2 woofers locked up tight as a drum, I replaced that component set with a set from RE. They've been fine.

Until today. I hopped in the car today and both midbasses were not playing. Tweeters were playing, and subs were playing. No midbasses. They were working fine when I shut the car off last night.

Just like with the CDTs, after the interior of the car sufficiently warmed up, one midbass came back online, followed by the other shortly after. When they come back, they have a short period of static before quickly coming back on 100%.

I have to assume that this issue is either the woofers or the crossovers, but why would I have the exact same problem in all 4 drivers that have been installed in the car?

Anybody have any experience with this issue? I can't keep replacing components every winter.

thaforce

It is possible that some of the components in the crossover network are temperature sensative, most likely a capacitor.

cub and Matt

OK... Sounds strange to me as well. Have you tried hooking up the woofer directly to the amp. This will eliminate the crossover as the problem or confirm that the crossover is the problem. If it is the woofer, I see you live in Vermont. I know it gets cold there, so I am wondering if maybe the voice coils are ferrofluid cooled. I realize this is reaching, but could the ferrofluid actually "freeze". Let me know about the crossover findings. I will then do some research.

NEEDAZ

Does it do it consistently enough to get a scope on the amp output when things are acting up? I'd start with the amp. It's common to both problems. What's the make and model. And the no audio - noise/distorted audio - working sounds like pre-amp/driver stage bias problem. I have heard this when I've disable the protection circuit to trouble shot. But it's not like the protection always works like it should. It would send the output rail to rail slowly, think like 5-20Hz. If you using the OE x-overs I doubt they have much in the way of low frequency filtering. Even if it was at 30-40Hz you probably wouldn't notice it from those drivers. But 30Hz rail to rail would leave it's mark on the mid drivers. Tweeters would be safe. Odd it's both channels. This would be vary unusual, but you always have the odd ball problems.


And as an extra for you Jim. Two years ago I got play with an early version of this thing. Though it was vary cool.
http://www.mcminone.com/product.asp?...0&info=details

Jim85IROC

iTrader: (2)

I met one of the guys who developed the woofer tester recently. He gave a nice demo of the Woofer Tester Professional model. Interesting stuff. What I was most interested in was the shift in fs and qts in his sample woofer as he changed input voltage during the testing. The extreme non-linearity of a typical driver is really quite an obstacle to overcome when trying to build a system that sounds good at low and high volumes.

Overall, the Woofer Tester 2 seems a bit limited in what it can do for the money, but seems to be quite user-friendly. I do like how quickly and easily the WT2 gets the t/s params. I've got Soundeasy, and besides having an incredibly cryptic manual, it's just not an intuitive program at all. I haven't even gotten to building my wallin jig so that I can do my t/s testing in Soundeasy. I'm still trying to figure out how to get my measured phase response to match reality.

Anyway, back to my problem. I got out of work yesterday and the woofers were working great. Played nicely the whole way home. I started the car today and no woofers again. They didn't come on at all during my 40 minute ride to work. When I got to work, I put my ear down to them, and sure as hell, there was absolutely no sound coming out of them, but the tweeters and subs were playing normally.

The amp is a 4x50 Phoenix Gold Tantrum t400.4. If these woofers were getting a 20-30hz rail voltage, I would expect it to cause the doors to resonate very badly, which I'm not experiencing. They're either functioning properly, or they're off. Even when blowing up speakers, I've never had a situation where they intermittantly worked like this. If there's a 30hz rail voltage melting my voice coils, then so be it, but if that were the case, they wouldn't work properly the rest of the time.

With the last pair of speakers, when they would cut out, sometimes I could crank the volume and they'd come back on. Higher voltage can jump a gap in a bad solder joint. Every indication said that it was the passive filter. Then the 2nd woofer did the same thing. Now 2 more in an entirely different set of speakers is doing it. It's GOT to be something upstream, but man... I still can't figure out why it's only effecting the woofers.

NEEDAZ

It would necessarily be 30-40 Hz. May be 5Hz, or DC. That 80Hz filter in the amp wouldn't matter, it all pre-amp. And I don't think the OE X-overs would have much if any low frequency filtering on the woofers. This is one of these cheepo portable scopes would come in handy.
http://www.allelectronics.com/cgi-bi...LLOSCOPE_.html
It's the only thing I can think of that would damage the woofers. Or you just have had 4 woofers god bad, but how likely is that?

Jim85IROC

iTrader: (2)

Not very. But... even if it's 5hz or DC like you're saying, wouldn't any damage inflicted to the woofers be permanent damage? These either play flawlessly, or they don't play at all, and so far it's been consistant. On my way to work they have been silent, and on my way home, fine. Yesterday they worked all day. Today, I didn't take the car, but since it was real cold overnight (10 degrees), I'm expecting a phone call around 11:00 today with a complaint that her speakers don't work.

I guess it's time to buy some probes for my oscilloscope and try to figure out what the hell is going on.

NEEDAZ

I've never worked on a lot of the PG stuff, but i Think I remember something about some of the Tantrum amps having problems with bad solder joints. Thins is grasping at straws, but say you had two bad connections. One could be just about any where in the signal path and cause no signal out. Then one that was throwing the bias out of whack. You almost never see amp killing speakers any more with the protection circuit worked out now, but in the past it wasn't uncommon.
But we're just bouncing around guesses at this point. We need more info.

1991CamaroRslow

iTrader: (3)

Capacitors in your crossover network have gone bad is my vote. As mentioned earlier pull the crossovers out and play the mid bass if they work plug it back up the way it was and go over the crossover with a heat gun or hair dryer see if that brings the mid bass online when they're shut down. You're still using the CDT crossovers correct?

ScrapMaker

I blame it on the cold weather.

cold weather sucks.

Jim85IROC

iTrader: (2)

Yes, the cold is the culprit, but I'm trying to find out what item the cold is effecting.

It's not caps in the crossover. There aren't any caps in series with the woofers, only shunted, so even if they did sh*t out, there would still be output from the woofers. I also find it highly unlikely, after over 15 years of car audio in the cold, that 2 different sets of crossovers would exhibit the exact same problem in the same car. Something else is driving this issue, and as much as it pains me to say "amplifier" because I haven't yet figured out how it could possibly cause what's happening, it's got to have something to do with it. I think Needaz is the most qualified of any of us when providing theories/suggestions, and although I'm not 100% ready to agree with everything he's said, I think that he's definately the closest to solving this.

ScrapMaker

I'm assuming you've bench-tested the components after they 'failed,' right? To make sure that it's not the amp? Or are the components clearly being damaged?

Jim85IROC

iTrader: (2)

the 2nd set of speakers is still in the car, and thanks to the somewhat warmer temps, has been working fine the last few days.

The first set I pulled out, I examined. One of the woofers was siezed up so tight I couldn't even move the cone, the other felt fine but I did not hook it up to an audio source.

You know what... I think I might have just figured this out.

The woofers are in the doors. That one I pulled out was rusty and I attributed the lack of cone movement to a rusty/corroded pole piece against the voice coil.

This happens when it's cold.

There's water in the voice coil gap. When it freezes, speakers no worky.

Time for some compressed air and a pair of those foam baffle thingies.

1991CamaroRslow

iTrader: (3)

Didn't realize you had swapped the crossovers, and when the caps short out in a 12db per octave passive setup they can shut off the woofers but usually it will mess with the tweeters as well, I've had a set of Kicker Impulse crossovers short out on me however they never came back online, and the tweeters had alot of static coming through them; culprit was a blown cap in the board. I'm actually pretty sure I still have that particular crossover somewhere. I will have to agree with your theory that the woofers are actually freezing, and that does suck, foam baffles should fix that issue for you. Good luck on it.

NEEDAZ

I find it hard it agree with me some times too.

NOT in the kick's, what the h... If this was a Honda with the door speaker I would have said window seals. They just do that. Curve ball on the door speakers. I think you're probably right on the money now. When you pull the drivers out for the baffles, check the speaker out real close. The Handa's would look good but have corrosion on the coils. They may real 4 ohms one day, but on a good humid day all bets where off. I've had to void a lot of warrantys over this one. You'll know. Good luck.

Jim85IROC

iTrader: (2)

It's a camry, but similar situation otherwise. I suppose I should have mentioned that ahead of time.

ScrapMaker

How do those comps sound in the doors, as opposed to the kicks you have custom-built for your 3rdgen?

Jim85IROC

iTrader: (2)

Tonal balance is better, but they don't image nearly as well. These RE woofers are a high Q design that's made for an IB door install, so when I had them in my kicks, they were predictably thick in the midbass. They're much smoother in the doors, but the image is not as far forward, and doesn't have the pinpoint accuracy.

ScrapMaker

Most components prefer IB over small sealed, right?

I wonder how they would sound in 4thgen kickpanels, (like my WS6,) compared to your kicks, or the doors in your Camry...

I've always been interested in messing with different 'box' designs and whatnot for various woofers... but I never have the money!! hehe oh well..

I have my eyes set on the edi6500s... they are nice for the money... although I find it suspicious that they keep dropping the price!! makes me wonder... Everyone still really likes them though, so I dunno...

Jim85IROC

iTrader: (2)

I'm not familar with 4th gen kicks, but if the area is small like in my kicks, chances are you'll face similar issues.

Most car woofers have a high Qts so that they'll have a good bass response in doors, which for all intents and purposes is an infinate baffle. The woofers that I'm using in my kicks have a lower Qts in order to help eliminate the midbass bump associated with the tiny enclosure. In that regard, my experiment seemed to be sucessful. While there's still a bit too much midbass, it's nowhere near as bad as with other "car" woofers I've used in the kicks. The high-pass rolloff seems to be a bit higher than I'd hoped and I don't have complete integration with the subs, but it's not too bad. Once I get time to figure out my measurement software I'll start taking measurements and build a new filter for the components I'm designing, and part of that filter will include a notch filter to deal with any remaining midbass issues.

ScrapMaker

sounds like a winner.

Jim85IROC

iTrader: (2)

Yeah, now I just need to design a crossover that doesn't suck so bad! Of course, since I started this project last year, Tymphany discontinued the tweeters that I had chosen, so now I need to start over with new, more expensive tweeters. This will give me more crossover options, but it'll also raise the price of the kicks.

ScrapMaker

bleh, that's never good...

people have been eagerly awaiting your precious kicks!!

Jim85IROC

iTrader: (2)

I've been awaiting a chance to finally work on them too! Most of my "need to finish before winter" projects are nearing completion, and since we don't have any snow yet, my snowmobiling hasn't started yet. Maybe right after Christmas I'll have a chance to start playing with those again.

cub and Matt

What year is your camry? I have an 06 Solara and I am considering upgrading my system in it (Its my work car/daily driver). I am concerned about the whole water leakage/window seal thing. Is this a common thing with Toyota's? Thanks

Jim85IROC

iTrader: (2)

It's a 92, and I know nothing about them exept that they get better gas milage than my 87 GMC 454 1-ton pickup, which is the ONLY reason I drive it.

It's my fiance's car, but I use it in the winter. Try www.toyotanation.com. They're likely to have answers for you.

NEEDAZ

I still say curve ball on the import.
cub and matt, If I remember right it was more a Honda thing.

cub and Matt

Well if curve ball means avoid them, I understand. I do own a 03 Suburban. Plus we have the 91 parked in the drive. Got the toyota because we live 25 miles 1 way from where we work. The Toyota gets about 37 miles to the gallon. It is next after the TA gets finished.

brians88gta

maynot be your component but signal feed into the amp ive had real bad expierences with bad rca cables and rotory type controls on amps. gets to cold you find you have lots of loose conections. i would check over everything when its not workin to see if movin things around a little makes a connection

Jim85IROC

iTrader: (2)

thanks, but I've already determined the problem. Water in the voice coils of the midbass speakers is freezing. If it was upstream like an RCA, it wouldn't effect just the midbass drivers.

It was 31 today, and it predictably did the same thing until it warmed up a little and they came back on.

ScrapMaker

so water actually gets near the speakers? is it because of old age, or is that the way the car was designed?

NEEDAZ

From what the install shops where telling use (and I still can't remember for certain if it was Honda's or Toyota's) the cars all most all had visible cracking, I assume from age, of the rubber at the base or the window, or it didn't stay tight against the window the whole up and down travel. The just so happen to let the water drip straight down at the speaker.

ScrapMaker

Damn, I would assume that would damage much, much more than just the speakers...

luckily that can't happen with kick panels!

82TransAM_45

that would be honda there. i own a 91 civic hatch and if it rains hard enough i get water on my speakers as well so then i cant listen to my radio check your weather stripping would be a good thing to do. and make sure your window is sealing tight against the door jam seal. lol, i still need to fix mine lol.

Stealthy-One

hey look at it tis way. You can run more power to the comps since they are "liquid Cooled"!

NEEDAZ

First noticed the problem because of repeated amp IC dying in the HUs. When you have to put three amp ICs in a HU in three mounts, theres a problem and it's not the ICs. We had a run of them, maybe two or three a mounth for a year or so. Still see it from time to time.

Jim85IROC

iTrader: (2)

Car doors are designed to have water flow through them. If you get under any door, you'll see water drains spaced along the bottom inside "shelf" area. In this particular case, the stock speakers were shallow enough that their voice coil area was protected by the plastic trim ring that they mount to. The aftermarket speakers stick out the back of this ring, right in the way of the water apparently.

My father had to replace a couple doors for a woman because they rotted at the bottom and the power windows no longer worked. When he got the car, the drains were plugged and the doors had over a foot of water in them!!

NEEDAZ

A foot, the plastic under the door panel must have had a good seal. Pat Goss says to clean these drain holes every couple of years. I thought is was a to much water coming from the wrong places problem. Makes me want to hose down a Honda door and see where the water is running.

In your case, is there room to add an ABS plastic bent like a shade to keep the water off the drivers?

Jim85IROC

iTrader: (2)

I could rig something like that, but I'm probably just going to get those foam baffles and see what those do. Those should be almost 100% acoustically transparent at and below the midrange frequencies.