Thread: What's up with my BRAND NEW speakers??

Ohh man, I actually read through this whole thing. A lot of misconceptions and a lot of good advice...

Now for a lil background to help my advice.... I started working for the largest car audio shop in western New York at 17 as a sales guy. In the 10 years following, I have gone from sales, to installations, to owning my own shop, to dumping car audio all together Regardless, I have picked up quite a bit of knowledge in the process.

So lets break this down and keep things as simple as possible. I am going to explain things in simple terms, if others want to argue my points, feel free to send me a note and I would love to get technical, but just don't take over this thread.

1) The noise you hear is from overdriving the outputs of the head-unit, more or less making it push too much power to equal the volume you would like. What people have mentioned about clipping is dead on. We need to find out a way to get you the volume you want without clipping.

2) The speaker mounting charecteristics (sp?) of Ford trucks are rather lousy. One of the things you will want to do is ensure the front side of the speaker is sealed from the back side. They sell lil foam baffles that work rather well for what you are trying to do. You basically pull out the speakers, slide the cups over the back and mount them back in. A cheaper experiment you can try is simple duct tape. Remove the speaker covers and look for holes in the sheet metal that would allow air from the back of the speaker to come to the front. Then apply a couple layers of duct tape to it. It may help, i repeat, MAY. I usually do this on door speaker installations.

3) Yes, oval speakers have standing wave issues, all speakers do. Doing what I described in #2 will help. With a decent amplifier, you will never get to the degree where you will notice the difference between the standing wave characteristics of one speaker to another. The speakers you bought are excellent, don’t let anyone tell you otherwise.

4) Amplifiers and ohms… Let me make this a simple decision for you… Buy a decent named 4 channel amplifier. When I say decent, try to stay with brands you have heard of before. I personally like Phoenix Gold amplifiers from the mid 90’s. There are some great deals on these on ebay. Rockford Fosgate, a/d/s, PPi, Soundstream, Earthquake, even Pioneer and kenwood are all sufficient for what you are trying to do. Stay away from no name brands and weird brands that are a mix of two names you have heard of before. The major problem you will notice is ground noise on these weird amps, which is quite annoying, especially for someone just starting out.
Now if you buy a 50 watt per channel amp, it is NOT half as loud as a 100 watt amp. In fact, to double the volume of a 50 watt amplifier, you will actually have to give it about 10 times the power, or add several sets of speakers. Regardless, my point is a 50 watt amp will be plenty. Find an inexpensive 50 watt X 4 amp.
Why a 4 channel compared to a 2? Well its all about control. Chances are the rear speakers are very close to sensitivity (how efficient they are) compared to the fronts. But they are not exactly the same. What does this mean? Well if you run the fronts and rears off of one channel, one may be louder and there is nothing you can do about it. This would annoy the HELL out of me. I want to be able to turn the back down to a point where its maybe a lil stronger in the fronts than the rears. I like the control of a fader, its there for a reason. I realize you only have one set of RCAs out, but that’s ok, you can buy lil Y adapters for the RCAs so it feeds all 4 channels. Then you can use the gains (adjustments) on the amplifiers to work out volume in the front to the rear.
Don’t bother looking at 2 ohm ratings right now… Like I said above, more power is not needed. Just pay attention to the 4 ohm rating.

5)Wiring…. As they advised in an earlier post, just use a cheap 8 gauge kit. Make sure you fuse the power wire with the included fuse. Next make sure you ground the amplifier to a CLEAN ground. This means making your own screw point by finding a strong piece of metal, cleaning off the paint to make a shiny metal surface about the size of a quarter, and using a self tapping screw to attach the ground. Toss a lil grease on top of it to prevent corrosion.
Next, as described, its probably easiest just to run all 4 pair of speaker wires behind the head-unit and tap into the factory wiring. It will take some thinking to make sure you have all of them hooked up to the proper location (I use a 9 volt battery as a way to “pop” the speaker so I know which wire goes where). But once you figure it out you are good to go.

I know this is a lot, so if you have any questions let us know and we will try to help.

Originally Posted by tbird2340

WOW... Thanks for that informative post Will.. Some of the things I got out of it..

Basically stay away from the two amps I posted links too right ?

Well yeah pretty much. You see you can get away with cheaper amps, but you want to have an investment, not a headache. Used amplifiers are so cheap that I really recommend getting a good named brand. I spent years on the repair end of home and car electronics and its the inside that counts. Most of the amps I have mentioned all have decent components and that is VERY important. It just means a stronger, better sounding amp (yes yes audiophiles, i know the Autolab 2000 challenge) can often be a better value than a huge power, weak internal amp. There is a reason they are a lil pricey... its because they are better.

Originally Posted by tbird2340

Also, Your #2 point may have something to do with my problem... I originally had 5x7's in my rears (stock) and I had to sorta jerry rig to get my 6X9's to fit. I had to drill new holes to get them in.. Your saying to make SURE the speaker is FLUSH with the door? That no air can get through??

Thanks for the amp advice. So now I'm basically looking for a 4 channel amp that is running 50 X 4 RMS at 4 OHMS.

Exactly! Yeah, lets get that speaker mounted correctly. It mush be flush. If that means getting some tin snips out and cutting a lil metal, then do it. It needs a strong seal, a strong baffle to prevent the sound waves eminating from the back to cancel out those in the front. Since sound travels via vibration of air molecules, we have to seperate the air in the back, from the air in the front. Make sense?

And yeah, buy a nice lil 50 watt X4 amp. Make it a decent one and plan on holding onto it for a decade or so. This lil guy will be with you for a long time!

did you ever get around to checking those infinities for standing waves?

Originally Posted by WhiteRabbit

did you ever get around to checking those infinities for standing waves?

Are you sure you are using the proper term here? A speaker by itself cannot produce a standing wave based upon cone flex. A standing wave is produced by the interaction of two wave lengths moving towards each other. This is normally caused by the reflection of a previous wave back to the origin (speaker). That said, the standing wave is dependent upon the physical properties of its environment, and not the speaker itself.

Secondly, you can not "see" a standing wave by looking at a speaker. You may be able to see the movement of the speaker, but not hear the proper volume. If thats the case, you have cancellation somewhere, or extremely low frequencies. but once again, it is not the speaker but the properties of the environment. Possible reflections or improper baffleing causes this all the time.

I can understand noticing a distortion at low frequencies with the Infinity speakers. They are simply not designed to produce low volumes in a free-air environment. Using a crossover helps this. But I will guarantee that the speaker does not move anyway but linearly. Yes, maybe the cone flex is visible, but you would have to have a hell of an eye.

Non-circular speakers do suffer from cone flex issues. Cone flex changes the harmonics of a speaker slightly, causing it to "ring" at a frequency other than that in which it is trying to reproduce, especially at high volume levels. This problem is so minimal that only the highest of audiophiles get a bug up their butt about it.
I prefer a round speaker for different reasons. I stopped selling 4x3/5x7/6x8/6x9s a long time ago. Instead, I would sell a normal round speaker and an adapter plate. For the money, people could purchase a higher quality 6.5" and place it in the 6x9 slot. It always amazed me how much companies like pioneer would charge for the oval speakers compared to their relative quality.

Anyways, i really can not agree that these speakers, or any speaker alone, can have inherent standing wave issues. Remember, its the enclosure/environment....