What's up with my BRAND NEW speakers??

**tbird2340** · 10-12-2004, 07:35 PM

OK.. Well I will never get subs (wife already axed that plan... it's so teenager she says...)... So I don't think I will ever need another amp.. Here are some questions..

For power, I have a 12 gauge wire for my carputer. If I run a 4 gauge should I just jump off that and take out the existing 12 that goes to my carputer?

Also, I have a truck. Can someone recommend where I would put my amp? And to hook it up.. I should just take the wires that are going to the headunit and snip them there then extend them to the amp right?

**Snootch** · 10-12-2004, 08:03 PM

Woahhh, Woahh, this is getting out of hand. Let me explain a few things...
Your Infinity speakers, like all coaxial factory-replacement speakers are 4 Ohm. The "100 x 2" rating you quoted earlier may be the output at 4 ohms, or 2 ohms, it depends on what the specifications say. A few of the amps I posted Ebay links to were 75watts x 2 @ 4 Ohms, meaning when the two channel amp (x 2) is connected to two 4 ohm speakers, each 4 ohm speaker "sees" 75 watts. If you increased the # of speakers to 4, and wired the pairs in parallel, (+ to +, - to - for the 2 left speakers, ditto for the right ones) the amp no longer "sees" 4 ohms. Because of the parallel wiring of adding another speaker to each channel, the amp now "sees" 2 ohms. Now that the amplifier "sees" 2 ohms per channel, it will double it's power output, going from 75 watts, to 150 watts. Each speaker will "see" a portion of this power, in this case 75 watts. I have a feeling that price is your main objective in putting this toghether. If so, buy a used 2-channel amp, and then you will only need a two-channel amp wiring kit, eliminating the extra RCA cable you would of needed for a 4-channel amp setup.
Simply, buy this amp: http://cgi.ebay.com/ws/eBayISAPI.dll...725125537&rd=1

This wiring kit: Complete 8 Gauge Amplifier Installation Kit- $18.00
http://www.knukonceptz.com/productDe...?prodID=KOLAK8

You don't need 4 gauge power wire, because you:
a- aren't running more that 500 watts, and
b- there's what, 8, 10 feet between the battery and behind the seat in a pick-up truck? 4 gauge wire would be overkill. The only way I would recommend it, is if you planned on adding another amp for a subwoofer later.

Then get some blue crimp connectors from Radio Shack, or Home depot, or similar store: $5.00

Run the speaker wire that comes in the kit from the output of the amp to the dash, behind the radio. Connect the other ends with the blue connectors to the wires that go to the speakers. Tape off the speaker wires coming out of the deck. Run the RCA cable that comes in the amp wiring kit from the amp's RCA inputs to the front RCA outputs of the deck. Run the 8 gauge blue power wire from the battery to the supplied fuse holder (within 18"), then to the power input on the amp. Run the ground wire from the amp to the silver 8 gauge wire, then to a nearby clean, solid metal ground, like a seatbelt bolt. Mount the amp to a wood plate, not to the metal of the truck, this will create noise if it is done. Connect the remote output of the deck to the middle wire in the RCA's, then to the remote input on the deck. Set the gain(s) control on the amplifier to full minimum (counterclockwise). Play some familiar music in the CD deck at it's full undistorted output, then slowly increase the gain on the amp until you hear distortion. Back the gain down slightly, and you're done! Estimating that the amp above goes for $75, you've spent a total of $98 plus shipping and tax, and your system is a heck of alot cleaner, louder, and distortion-free.

**tbird2340** · 10-13-2004, 08:13 AM

Snooth, thanks for taking the time to post that great reply... Although I have just one more question.. I thought I was supposed to run the speakers @ 4 ohms w/ an amp. If I do what your saying than that will drop them down to running @ 2 ohms with the amp. What does that do?

I really do appreciate the writeup.... Since you made the decision for me (which I needed) I will probably try to win that amp if you explain the OHM thing to me.

Thanks man...

**Snootch** · 10-13-2004, 04:47 PM

Well, it's pretty simple really..

The "standard" impedance (think resistance) of home speakers is 8 Ohms, and for mobile audio, it is generally 4 Ohms. Therefore, car audio manufacturers spec and build their amplifiers to put out a set amount of power at 4 Ohms. Most all amplifiers will be able to double their power output when the resistance, or impedance measured in Ohms, drops. This allows electrical current to flow more freely through the amplifier. However, this will cause the amp to draw more power, and develop more heat. Some amplifiers, are stable into even lower impedances, like 1 or .5 ohms, and will have a power increase as the resistance falls. There are so called "cheater" amps in competition that are rated at 50 x 2 watts (at 4 Ohms). However the competitors using these amps are wiring them into speaker resistances of .5 ohms, which allow the "cheater" amp to produce tons more output, and suddenly be a 400 x 2 amp. Earlier I said that amps are "stable" into lower impedances? "stable" simply means that the amp is built for that kind of a load. Most amps (including the one Ebay audction one) is stable into 2 Ohms stereo. If amps not stable, or designed for lower impedances are subjected to them, they will go into protection mode, get really hot, and never turn on again, or start a nice, toasty carpet fire in your ride, so don't go wiring lower impedances into the amp that what it is stable to, or it could become rather expensive. I dug up some information on the Basic Car Audio website ( http://www.bcae1.com/ )for you to read, and maybe it'll help you if my explanation is as clear as mud:

http://www.bcae1.com/voltage.htm
http://www.bcae1.com/current.htm
http://www.bcae1.com/amp.htm
http://www.bcae1.com/resistnc.htm
http://www.bcae1.com/power.htm
http://www.bcae1.com/watt.htm
http://www.bcae1.com/amplfier.htm
http://www.bcae1.com/2ltlpwr.htm
http://www.bcae1.com/srsparll.htm

Happy reading, and i'll be happy to answer any questions I can. Some good car audio websites that I think there is good info on, and I frequent are:
http://www.fbodyaudio.com/cgi-bin/yabb/YaBB.pl
http://www.carsound.com/cgi-bin/UBB_CGI/ultimatebb.cgi/

Good luck with your system!

**WhiteRabbit** · 10-13-2004, 08:55 PM

your problem is actually in fact that you bought infinity kappa. kappas are famous for having cone resonances, especially their oval speakers. (actually exclusively their oval speakers in my own experience) and amplifier may help, but only if you use the high pass filter to take out a majority of the lower frequency range (at 40 RMS, I had to set the cutoff at aound 200 Hz ish for my 6x9's to eliminate resonance.)

test for yourself. get in a position to see the speaekr itself, and play something bassy tha tyou know causeds the distortion, and crank it. do you see standing waves in the cone of the speaker? then youve got the classic kappa cone flex! an amp wont fix it, its the crossover that does. if you have a pioneer, you can set FIE to 250 and it should help a bunch.

lemme know if any of this does or does not work

**tbird2340** · 10-17-2004, 04:04 PM

Snooth... Can you recommend me some other amps?? I lost that one on ebay

Hold up... Your saying an amp may NOT fix this problem?? I don't have the loot to be dishin out if this ain't gonna fix this..

**WhiteRabbit** · 10-18-2004, 09:01 PM

get to a point where you can look at the speaker itself while its playing. if you see cone resonance, like standing waves on teh cone itself while its playing, then you have a classic kappa problem.

the waves are caused by playing frequencies lower than the cone can support without flexing. make sure your cone doesnt flex at all.

unfortunately, you might not like the fix. the fix is to turn up the high pass filter on your crossover until the problem goes away. this could be as high as 150 Hz or even more. talk about losing all semblance of midbass!

if you have no crossover, then an amp would be the way to go, since itll have a crossover built in. but that DOES seem like a rather expensive solution!

but if your radio has a crossover on it that you can just set to whatever it takes to fix the resonance, then *shrug* free is better than $100......

**tbird2340** · 10-19-2004, 07:49 AM

WhiteRabbit, will this be easy to see if it's happening? I don't really know what cone resonance is...

The two pairs of speakers I bought had crossovers come with them. They are a little box that sits between the deck and speaker on each speaker.

Thanks

**WhiteRabbit** · 10-19-2004, 10:32 PM

totally easy to see.

I'm sure you already know a speaker cone should just move in and out uniformly. So if you happen to see the cone wobbling around, you know you have the resonance!

yeah, its pretty obvious when it happens