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I recently installed a system in the Gf's car, and it works great. Polk DB651s up front, some scrap yard sonys in the back (not bad actually) and two MTX 4500's in the trunk. Got about 100 RMS going to each speaker (820W 4chan Power Acoustik) and 200RMS to each sub (840W 2chan Power Acoustik)


The speaker amp has a full crossover. I tuned it by first turning it to LPF, and tuning first the front and then rear speakers untill there was just a little bass coming through at high to moderate volume. Then I did the HPF, but the claps and 's's and cymbals are still always too loud, no matter where I set it (I believe 240-20khz? sound right?) All the gains are about the middle. (LOC, Amps) She has a stock headunit (horray for 2channel eq!) and turning the trebel half down seems to help.

Is there a way to coax out more of the midrange?

Thanks for the advice,

Ryan

There is no way to drop the DB's a few on the upper ranges? I have separate crossovers for my components, and I dropped my tweets -6DB so they weren't harsh anymore.

hm. No, no external xovers.... These are 2way coax, built in non-adjustable xover (aka capacitor/inductor)

Would and inline resistor mess things up? Just on the tweet parallel....

geaaa left + ride side tweets in parallel off one left n one right ch. on amp.... As long as u don care about fading. That'll cut the tweets wattage down. Or just turn the treble down on the deck/ change the treble boost frequency on the deck to a lower frequency if its possible.

Just an FYI, the range of human hearing is between 20Hz and 20,000Hz (or 20kHz). Therefore, if your amp is turned up to HPF - its for high frequency; LPF is for lower freqency. Every speaker is rated with a frequency response range. Subwoofers would have a frequency response of something like 10Hz - 9000Hz. Since we can only hear as low as 20Hz, you wouldn't hear anything lower than that. Same thing with high frequency.

If you were to turn down the HPF and turn up the LPF, that would put the range right in the middle. You should also turn down the treble and maybe turn up the mid a little more. Bass, Mid, and Treble all have different frequency ranges. This is where you can tune the stereo in a way that's pleasing/not damaging to your ears.

With regard to decibels, one thing to keep in mind is that we can handle 85dB for 12 hours straight before permanent hearing damage (hearing loss) will occur. Each time you step up 5dB from there, the time decreases by half:

90dB - 6 hours
95dB - 3 hours
100dB - 1.5 hours
105dB - 45mins
110dB - 22mins (rock concerts)
115dB - 10 mins
120dB - 5 mins
etc.....

I had friends that really pushed their tweeters and to me it feels like someone is firing glass into my ear.

Damaging your hearing will result in a smaller range of hearing (ever notice that older construction workers can't hear high-pitched noises?)

Hope this helps... A little overkill but that's my nature

They do make bass blockers which filter out low frequency from speakers, to avoid blowing them, so I don't see why you wouldn't be able to block higher frequencies.....

Resistors exist to prevent speakers from exceeding their frequency response, causing distortion. Distortion will blow speakers.

Sir, I know all of this. I have made my own PCB's, and screwed around a lot with electronics. Her amp is HPF/LPF which you would have read in my first post. I don't know if I mentioned it, but I tried setting the HPF all the way down, and said sounds were still overpowering at higher volumes.

She's getting used to it though, its just so different from the stock paper cones.

Raising the LPF won't do anything to affect said noises, just put more stress on the speakers. Thats what the two 10" in the trunk are for.

Adding inline resistors won't change the frequency responce, only the power recieved by the speaker. Amps are always the weakest link in the system, untill you melt your voice coil and cause issues in the circuit. What I think you're talking about is passive crossovers, which is a combination of a capacitor, where increasing farads take out more and more of the low, and inductors, where as inductance increases lowering the highs.

The idea with the resistor was to put a high power handling, low resistance resistor ( up to 200W ) in the tweeter parallel, in order to reduce the power going to the tweet, not reduce the frequency responce.

Lowering HPF still wasn't enough.

You are talking a fair bit below me

Oh..... a thousand pardons

lol

Can you adjust the angle of your tweeters at least to help decrease the amount of high frequency going into your ears?

No, we skimped and only got Db's (polk) no adjustabilty. Maybe I'll just tape something over them, lol.


I was thinking last night, and the reason that the exposure time to permanent damage halves is because bels are logarithmic functions, base 10 to be exact.