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Alpine MRV F407- running Tweeters off channels 1/2 high passed, and the woofers off channel 3/4 band-passed...

I have thought for a awhile now that my two tweeters were out of whack sound level wise- it is very subtle, and I thought maybe my right ear has some hearing degradation compare to the left or maybe the Tweet was blown... so I disconnected them and swapped channels temporarily, sure enough, there is a clear difference with sound range. Both channels power the speaker, but the sound is different.

Anybody even run into this? Is there a way to measure the output coming out of those two channels to see if it is in fact different?

I'm planning to bridge this Amp and run mid range speakers off it, and tweeters of the DSP.... anybody have a resource for Amp repair is needed?
 

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Are you comparing them installed? The left and right will sound different, even if the speakers have the same frequency response because of the crappy environment that is a car. This is why a good tune will use a DSP with indepenent EQ for the left and right, both sides will need to be EQ'd differently.

So, does the sound difference follow the speaker when you swapped the wiring? Do you have a test speaker that you can use for troubleshooting? You can put an ohm meter on both tweeters to make sure they have the same impedance.
 

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You can use a multimeter measure the voltage coming out of each channel of the amplifier and see if the voltage is the same with
Try turning your head unit up to 35 and then measure the voltage on the left channel and then right channel and see if they match ,
if they do , and you still have a major sound difference between the two . there may be a problem with the speaker cable


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Discussion Starter #4
Are you comparing them installed? The left and right will sound different, even if the speakers have the same frequency response because of the crappy environment that is a car. This is why a good tune will use a DSP with indepenent EQ for the left and right, both sides will need to be EQ'd differently.

So, does the sound difference follow the speaker when you swapped the wiring? Do you have a test speaker that you can use for troubleshooting? You can put an ohm meter on both tweeters to make sure they have the same impedance.
they are installed, surfaced mounted on the little back panel by the side mirror. The sound difference appears to be channel specific- so if I play tweeters on channels 1/2 (left and right), channel 1 sounds attenuated on the left side. If I swap the tweeters at the amp (switch speaker wires), channel 1 sounds attenuated on the right side (so both Tweeters are in good operating shape). That is with my head in between the two front seats head level... the very high frequencies on that channel 1 are not there, and it is not playing as loud. There is no level control for individual speakers (haven't got that DSP yet), so only the gain on amplifier itself, so the tweeters should be at the same level.

I ordered a Multimeter, should be here Friday.
 

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A multimeter will tell you a lot. In the meantime you can use some test tones and a free SPL meter app on your phone to compare the output of each side.
 

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Couldn't hurt to mark where the gain is set, and then exercise the pot a little. Could just be some slight imbalance on the pot.
 

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Can be dust in the gain, gain has loose solder, RCA has bad solder or ground. Beyond that is more complex. You can also measure the voltage at idle it should be very small (millivolts), if its larger the amp needs some love. They are great amps I'd still be running me some old alpine if I didn't need 125w/ch in this car. They are very repairable if you can find someone to do it.
 

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Comparing the electrical signal of two channels, relative to each other, is in the domain of an oscilloscope.
 
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