I've been tuning my system using 0db test tones at different frequencies and noticed a couple of things that really stood out.
The first is that at 160hz I get all kinds of crazy vibrations from the door and rear deck that I don't get at any other frequency. At 125hz and 200hz, there are no vibrations whatsoever.
The second is at 1,000hz. This frequency plays far louder than any of the others, even after using the EQ to cut it by several decibles. Is there anything in particular that would cause such a sharp peak there.
Are these common trouble spots in car audio, or is it unique to my system?
Are you using any sort of crossovers? The loudness at 1khz may be from multiple speakers playing that frequency.
First you've found the resonant frequency of your door and rear deck; the metal begins vibrating sympathetically with the speakers mounted to it. Best way to remove this is with dynamat, fatmat or something similar.
second; the human ear is most sensitive between 1-2K; that will explain the peak you hear. Unless you're using an RTA instead of doing it by ear, then as in the previous post you may have multiple speakers at that frequency. I don't know anything about your system, but to have a crossover at that point you'd have to be pretty invovled and well beyond a four-speaker-and-sub setup.
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Life moves pretty fast; if you don't stop and look around once in a while; you could miss it.
tomfin2000 wrote:
Are these common trouble spots in car audio, or is it unique to my system?
These are unique to your system/vehicle...
Cars usually have a 'resonant frequency' wherein the metal in the car... or parts of it... vibrates like crazy at that certain frequency... generally, its somewhere just above the subwoofer xover-point.
In your position, I'd play that frequency very loudly, then begin to peg down each rattle as you can with weather-stripping, foam filler, plastic ties.. whatever..
..not sure about the 1khz though..
How's your system setup now tom? You still using the VR stuff or you make a change? Still using the Alpine 5-channel?
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"I'm finished!" - Daniel Plainview
sedate wrote:
[quote=tomfin2000]How's your system setup now tom? You still using the VR stuff or you make a change? Still using the Alpine 5-channel?
Yeah, I'm still using the VR speakers and Alpine 5-channel. The only change I've made so far is that I picked up a JL Audio 12W1v2. I wanted to see if having more cone area and a sub that was rated closer to the 150 to 200 watts the Alpine is putting out would make a difference in the system's bass reponse. It made a little difference, but not a tremendous one.
What did make a difference was listening to the test tones and adjusting the EQ. In addition to what I mentioned above, the system was VERY loud at 80hz (the crossover point) so I cut it accordingly. Then I cut at 63hz a bit, and once I did that, everything from the 31.5hz tone on up was coming in loud and clear.
So I'm making some big strides in terms of getting the sound I want out what I have. After reading all the replies to my last post I realized that I didn't have a good enough understanding of my system and why it performed the way it did. Like you said, throwing money at the problem by buying a $600 amp wasn't going to solve anything. It's just going to take some triail and error until I know what I'm doing.
Cheers! Hell yea man I'm really glad to hear ya got everything working better for ya..
You sound extrodinarily discerning.. maybe you catch the bug right? I see *so* many obvious upgrade paths..
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"I'm finished!" - Daniel Plainview