I am trying to post a question and it will not allow me to do so.

My Q-
I have a couple of amps in my car
The amp driving the cabin is set to flat
the rear speakers have bass blockers
the front speakers are component w/crossover network

I am still getting a little distortion from the front stage

Q- what effect will it have if i set the amp high pass as well as the bass blockers and crossovers

effectively running 2 highpass filters in series

Hardware
Alpine cda-7838 head unit
Kenwood 7202 920watt 2 channel amp
Kenwood 7202 920watt 2 channel amp
Sony explode 400watt 12" subwoofer (1200watt max)
Q-logic bandpass box
Polk db5250 5.25" component speakers 100watt continuous (200watt max)
Polk db691 6x9 triaxial 100watt continuous (300 watt max)
Pyle 6 farad digital capacitor

thanks in advance
David Lundquist
gigalanman@msn.com

 

With all that amplification I'd be surprised if there wasn't "a little distortion". The usual method of debugging a problem is to divide and conquor. If you can find out which pathway is introducing the distortion you will have some chance of fixing the problem. I think it is unlikely that introducing more components will solve the problem.

 

I was more concerned about how the 2 high pass in series would effect the load impeadance or the cross over frequency points.

would the cross over frequency points increase twofold?
example they are currently 200Hz , would they then be @ 400Hz?

and the load...currently @ 2 ohms
how would that effect the load impeadance - important due to amp stability
(not stable under 2 ohm load)

thank you in advance
David Lundquist
gigalanman@msn.com

 

Is it your impression that you are hearing crossover distortion as opposed to distortion introduced by excessive gain aka clipping or limiting?

 

I believe the front right midwoofer cone rattles on occaision so I am assuming
the factory component crossover network is crossed over to high.
being that I have alot of mid bass and highs i am attempting to crossover (filter)the front @ a higher frequency.unfortunatley I dont have the x-over specs from PolkAudio as it is "trade secret" information.

I would like to try using the amplifiers highpass filter in conjuntion with the x-over ,but have concerns about causing a drop below 2 ohms.

I am not an electronics guy - I thought it would be better to ask someone who understands the theory.

I am curious what result ,in load impeadance ,running 2 filters in series would have on the load to the amp due to resistance change.

I know the r1*r2/r1+r2 parallel resistance equation and with my limited knowledge have wired a 2 ohm load to the amp.
will placing an additional filter (cap w/resister) in series on the positive lead
effect the total load (ohms)
thanks

 

I apoligize - not crossed over "to high " I ment crossed over to low
thanks

 

hello carguy,

before i can give a sensible answer to your query, let me clarify an issue which seems to bother you.

are we talking here of a power amp high pass filter in series to your PolkAudio x-over?

you have not mentioned at what audio level you're playing your system

another thing you said you have a 400+w per channel kenwood driving a 100w midrange?

moz

 

Filters are normally considered "linear" components and the response of two "linear" components is "linear". I understand the difference between crossover distortion in the power output stage of a push-pull amp but I'm less clear about distortion that may be introduced by the passive crossover networks placed between the amplifier output and the speaker.

Because I know of no useful purpose for a non-linear filter, I'm going to hazard a guess and say that the problem is in the amp or the mechanical mounting of the components. No combination of "linear" components can produce a non-linear effect such as distortion.

 

thank you papa bravo , I have switched the leads on the speakers front and back and the distorting speaker is now in the back.

you are correct, 1 channel on 1 amp is creating the failure
I will replace the amp.
thanks

 

it is probably wattage distortion so turn up the high pass filter till the distortion is gone. i have a 4 channel 480 w. amp with ch. a to sub, bridged with low filtered @ 32 hz and ch. b, high filtered with 2 - 8 in. mids at 100 hz and up and hadf to turn down the gains to about half volume so it doesnt have distortion at high volume. so putting 2 high filters in series will basiclly make the tweeters.
hope this helps

 

Its probably your ear drums beating against your skull.......