Car Audio Experts-Got a Question.

[biglou]

Here is the situation: I have a brand new 2002 F150 with the stock radio/CD player. I want to add a set of tweets that I have just to brighten up the sound a bit. I mounted them last night and when I got the first one tapped into the wiring harness, I thought I'd turn things on just to make sure I got the right wires. Well, the wires were correct, but above about 1/4-1/3 volume, the bass was overdriving the tweet making it pop and buzz. I could eliminate the problem by turning the bass down below 1/3, but of course, it sounds like crap like that. I do have caps inline to act as a crossover. I thought perhaps the polarity was wrong, so I switched the leads at the tweeter but it had no effect. I'm not sure what the value of the caps are that are installed right now. That may be the problem right there. I'm just looking to see if anyone has done a mod similar or exactly like this and might have an answer for me.

For the record, they are (were) tapped into the stock front speaker wiring in parallel.

Anyone have any ideas on this? Could the capacitors be too low powered to handle what the stock Ford system is putting out? That seems unlikely to me. Should I get a heavy-duty cap for a crossover or buy an actual crossover setup? I think the latter might be a waste of money since I only need to filter the tweets. Is there some sort of noise filter that could be used, or am I missing something obvious that is right in front of me?

Thanks in advance for any help.

 

[Offroadr]

Shouldn't of bought a Ford! :p

Actually I think your diagnosis is probably correct Lou. Low power and high ohm rating of the stock deck may be causing the problem.

A quick call to your fav audio store might be in order!

BTW I think I am gonna FINALLY get the CD/MP3 player installed in my truck next week! I have had the sub, amp, and speakers installed forever.

Running good aftermarket speakers on a stock deck is a big no no! Not enough power! :ugg:

 

[MrLuckey]

Taken from a source on the net:

A system that distorts at high volumes isn't defective, it's just being pushed too hard. If the sound is fine at low to moderate volumes, but gets fuzzy and distorted as you increase volume, that's a sign that you're underpowering the system. Contrary to popular belief, not having enough power can be more damaging to a speaker than having too much power. If the system sounds fine with the bass and treble controls set to flat, but when you turn up the bass or treble, it distorts, again, the system has reached its operational limit.

Are the stock speakers 4 or 8 ohm? How about the new ones? By wiring in parallel you have increased the load seen by your receiver. Have you thought about wiring in series since your factory rig is probably low on power already?

 

[Offroadr]

A great car stereo reference page

http://www.eatel.net/~amptech/elecdisc/caraudio.htm

 

[clutchcover]

Put crossovers in there at the appropriate frequency range.Tweets can't push bass. Try djusting your levels if you can. Use a noise filter, they don't work too well, but for what you are experiencing it may help.

 

[txvintage]

Parallel increases the load? :think:

 

[MrLuckey]

When wired in parallel it decreases the impedance/resistance and increases the amount of current!

 

[biglou]

I talked to a local audio shop and he said "Really? Hmmm..." He asked me what size caps I was using and I had to tell him that I wasn't sure. He said it sounds like too large of a cap. That would make them buzz like that. Recommended a 2.2 cap (mF, I'm assuming). Looks like I'm going to Radio Shack after work today!

 

[JuliusPleaser]

Lou, you may have shorted one or both of the speakers to the truck body. Try removing the speakers from their mounts while they are still connected. Older Fords had a goofy positive ground sound system, and the new ones may still have the same set up. I had to isolate the (aftermarket) metal speaker frames in my Ford work van 20 years ago so that they would operate without the popping/squealing that you describe.

What kind of tweeters are they? Are they mounted in metal?

 

[CanadianRidr]

Lou this thread looks familar :confused:

If you get really stuck go to www.f150world.com and check their forums. They are amazing and have VERY smart members :cool:

 

[biglou]

JP-They are totally isolated. Mounted to plastic trim. They are Kenwood. Not sure of the model, they are a few years old now.

CR-Thanks for the link. I'm on my way.

If the new caps don't do the trick, I'll just let it go. No big deal. This was to be a no-cost upgrade anyway. I shoulda remembered that there's no such thing! :)

 

[CanadianRidr]

http://www.f150world.com/forums/forum.asp?451

Lou that is the speaker forum, hopefully they can help! There is forums for every specific area on your truck :aj:

 

[a454elk]

If you fixed the prob by turning down the bass then the caps you have are incorrect and are letting the lows come through. Bass will blow a tweeter quicker than anything, don't run them anymore until you get the correct cap. The caps go inline so you have them right but may not have the size. Just ask a shop what size to use based on your tweeter and they can hook you up. Where did you get the ones you have now? Just curious.
Elk

 

[JuliusPleaser]

What he said. If your caps are the wrong value, they will be useless. It may be an impedance issue though.

(We may never hear the end of the story. Lou's probably out cruising chicks.)

 

[a454elk]

I can picture Lou blasting some love tunes through the speakers and they finally gave out!:):)

Tapping into a stock system really sucks anyway! Just ask Ridr, he was trying to put a boom box in his chicks 1978 Grenada and he wondered why it didn't work, DUH!!!:moon:

 

[clutchcover]

Big lou blasting Marvin Gay when all of a sudden smoke poors out and Marvin sounds like Alvin the Chipmunk on speed. Thats what pops into my head. But hey, chicks dig Chipmunk remixes.

 

[biglou]

Got it!

Sho nuff, it was the caps. I was on last night about 7:00 but "The Page Cannot Be Displayed" was all I got as I worked my way through the forums, so I logged off, went to bed and overslept for work today! The "caps" that I was using were unrecognizable as caps. I think they were coils or something. They were rated really weird (.187mH). I picked up a couple 1uf caps at Radio Shack, rewired things and it is kickin'! No love songs here. Just some Sepultura, "ROOTS, BLOODY ROOTS" :aj: thanks to the thread the other day! :)

The tweets did exactly what I wanted them to do-Brought the highs right on up there. The stereo in this thing is really quite impressive. For the time being, I doubt I will even pursue putting in a sub. I think I can live without it for now.... (That'll last about a week! :D )

The reason I didn't have the problem in the chevy was that it already had seperate tweets in the door from the factory, so that coil or whatever I had on my tweets was over and above the factory crossover. Glad I cut it open to see what it was and replaced it.

BTW-F150World.com rocks!

Thanks for the help, fellas.

 

[LoriKTM]

Glad it worked out, Lou!

Yes, those parts you had were inductors or coils. mH= "mili-Henries".

 

[biglou]

:( I've been away from the technical stuff for so long! I should remember this stuff...

 

[Danman]

(.187mH) It was a coil. They are rated by inductance. mH = Milli-Henry.