Tunning MY04 Stock HU + LOC + Amp + Bose Sub
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From: Irvine, SoCal
Tunning MY04 Stock HU + LOC + Amp + Bose Sub
This is my experience with tunning my MY04 car with these gears. I hope that it will help someone who like to retain the stock HU but like to enjoy music at highway speed. This does not imply that stock HU is as good as after market HU, because the simple fact that adding LOC to the stock HU to convert speaker level down to low level to feed to an external amp will introduce more noise to the whole system. I am very satisfy with my system as of now, specially for the amount of money I spent so far which is $550 total for parts and $200 for installation. I am in the process of upgrading stock HU to Rockford Fosgate RF8250, I hope that it will sound much better, I will if that is true or not. One thing for sure is the improvement from stock system to this new system is amazing to me, more than I expected. Thanks to Phil(PJK3) and Dave(NFRs2000NYC) for help me in upgrading ny system.
--------
My system includes these gears:
MY04 Stock Head Unit - made by Clarion
Door: Infinity Kappa Perfect 6.1
Rear Panels: Infinity Kappa 52.5i
Amp: Memphis 16-MC2004 - 50Wrms x 4 @ 4ohm with 13.8V input
Sub: RSX-S Powered Bose Subwoofer - 100W max, less than 50W RMS
LOCs: one 4-channel PAC OEM-2 for connecting HU's front and rear speaker outputs to Amp, one 2-channel for connecting HU's rear speaker output to Bose Sub.
Tunning:
Both LOC's gain controls are very small screws, you need a small screw driver that are used for eye glasses, you also may need two very small color markers.
MY04 HU's volume control is maxed out at 40, it started to produce some noise at about 28 with stock speakers. The maximum volume I will ever set is 25, to get a little noise from stock HU as possible, I'd tuned my system with volume set no higher than 20. The different of 5 is the reserved. All the tunning are done in closed garage to minimize ambience noise.
First I turn all LOC's gain controls clockwise to maximum, marked the maximum position with one marker, turn gain controls counter-clockwise to minimum, marked the minimum position with the same marker, then I marked the middle of the two positions to be center.
The amp front and rear filters were set at High-Pass, with the Front at 50Hz and Rear at 70-80Hz. With both front and rear gain controls of the amp set to about 8:30 or about 15% and all LOC's gain controls at about the same, I turned on the HU with volume set at 20 with Fader and Balance are set to tune one channel at a time, I'd first work on Front Left speaker. Using very small screw driver, I started to turn the corresponding gain control slowly until I started to hear some noise, i.e., the music started to distort, then I turned the gain backward (counter-clockwise) about half hour (about 15 degree) (Min position is at 7 o'clock and Max is at 5 o'clock, so the total range is 10 hours), to be sure that this is the correct position that will produce minimum noise, I tried a few more songs with knee down and listened to music at about 3 feet with door open, then I marked this position with the second marker, as of now the Front Left gain control has 4 markers: Min, Max, Center and Current Gain.
The position of the Front Left gain control is used to quickly adjust the other 3 gain controls. Next is tunning the Right Front speaker, I first listened to the same musics at the same position with the right door open and left door closed, I fine tune the Right Front gain to match the sound of the Left Front, I then marked the position of the gain after satisfied with the tunning. To verify that they are balanced, I sat in driver seat then in passenger seat to test. In driver seat I hear the left speaker sounded a little louder, and in passenger seat I hear the right speaker louder than the left speaker by just the same amount. This tell me they were very much balanced.
To tune the rear speakers, I disconnected the Sub power wire and moved the seat forward. With Fader and Balance controls set to one rear speaker at a time, I tried to fine tune the gains so that the sound pressure of the rear speakers are about 80% to 90% of the front. After all fine tunning were done, I marked the positions of the rear gains. I do the listening test for rear speakers as I did for the fronts, with the driver seat adjusted for normal driving position and the passenger seat at similar position so that both seats will effect the rear speakers the same amount.
Until now, the sound is fairly low because the amp's gain controls were set at about 15%. The next steps were adjusting the amp gains for Front and Rear speakers. You may want to take a break at this time, to start the engine (after open garage door) to re-charge the battery for 10 minutes or so. You do not want to have your battery totally discharged after your stereo had been on for a long time.
After the needed brake, it was time to adjust the amp, after turned off the engine and closed the garage door. This time I turned the HU volume down to 10 and Fader and Balance to Left Front only, then I started turn up the front gain control while listening for noise, I marked the position where I started to hear some distortion, that will be the maximum the Front gain will ever be. I turned it backward by 1 hour (about 30 degree), listened to a few songs to learn what the sound was like for Front Left speaker. I then changed the Balance to Front Right speaker, listening to the same songs to make sure that Front and Rear are still balance with each other. I then sat in the driver seat with both doors closed and listen to more songs to see if anything wrong, after one song, I moved to passenger seat and listen to the same song again. After satisfying with Left and Right balance, I turned up the volume to 15 then to 20 to see how loud they were and to check for noise at higher level. No noise so far, then I turned up the volume to 25 to check for noise and to see how loud at this near maximum level. It was so loud that I had to turn down the amp gain about 1/2 hour (15 degree), this will also reduce the potential noise generated by the amp. The sound is still very loud, but at a more reasonable level and this from only two front speakers. This step is repeated for tunning the rear speakers. After rear speaker gain were adjusted, I changed the Fader to have all four speakers on to check the balance of front and rear, I found that I like it best with front speakers at about 10% to 15% louder than the rears, by adjusted the amp rear gain down a tad.
After Front and Rear speakers are done, I disconnected the rear speaker, re-connected the Bose Sub, adjusted the fader to the Rear only to tune the sub by adjusting the second LOC gain control. I repeated the step above, i.e., Volume was set at 10, adjust the gain until I started to hear distortion, turned down the gain by 1 hour (30 degree), adjusted the fader to listen to music with Front and Sub, I then adjusted the gain of the Sub's LOC to match with the front. Then listen to music at higher volume level at 15, the at 20 and finally at 25. After some listening, I were satisfied with the Sub volume, I then re-connected the rear speakers. Listened to all speakers including the sub, I found that the rear speakers and the sub at this time is a little too loud and it seem to have a very little distortion from the rear, I re-adjusted the gain of the Sub's LOC gain down by 1/2 hour (15 degree) and the amp rear gain the same amount. Re-played the same musics again with both top up and down, door closed, windows up and down, in both seats. With top up I can hear much more bass from the Bose Sub, I had to turn down the rear a little. With top down and with fader adjusted back to center, the total sound were much more balance.
All comments, suggestions and critics are welcome
--------
My system includes these gears:
MY04 Stock Head Unit - made by Clarion
Door: Infinity Kappa Perfect 6.1
Rear Panels: Infinity Kappa 52.5i
Amp: Memphis 16-MC2004 - 50Wrms x 4 @ 4ohm with 13.8V input
Sub: RSX-S Powered Bose Subwoofer - 100W max, less than 50W RMS
LOCs: one 4-channel PAC OEM-2 for connecting HU's front and rear speaker outputs to Amp, one 2-channel for connecting HU's rear speaker output to Bose Sub.
Tunning:
Both LOC's gain controls are very small screws, you need a small screw driver that are used for eye glasses, you also may need two very small color markers.
MY04 HU's volume control is maxed out at 40, it started to produce some noise at about 28 with stock speakers. The maximum volume I will ever set is 25, to get a little noise from stock HU as possible, I'd tuned my system with volume set no higher than 20. The different of 5 is the reserved. All the tunning are done in closed garage to minimize ambience noise.
First I turn all LOC's gain controls clockwise to maximum, marked the maximum position with one marker, turn gain controls counter-clockwise to minimum, marked the minimum position with the same marker, then I marked the middle of the two positions to be center.
The amp front and rear filters were set at High-Pass, with the Front at 50Hz and Rear at 70-80Hz. With both front and rear gain controls of the amp set to about 8:30 or about 15% and all LOC's gain controls at about the same, I turned on the HU with volume set at 20 with Fader and Balance are set to tune one channel at a time, I'd first work on Front Left speaker. Using very small screw driver, I started to turn the corresponding gain control slowly until I started to hear some noise, i.e., the music started to distort, then I turned the gain backward (counter-clockwise) about half hour (about 15 degree) (Min position is at 7 o'clock and Max is at 5 o'clock, so the total range is 10 hours), to be sure that this is the correct position that will produce minimum noise, I tried a few more songs with knee down and listened to music at about 3 feet with door open, then I marked this position with the second marker, as of now the Front Left gain control has 4 markers: Min, Max, Center and Current Gain.
The position of the Front Left gain control is used to quickly adjust the other 3 gain controls. Next is tunning the Right Front speaker, I first listened to the same musics at the same position with the right door open and left door closed, I fine tune the Right Front gain to match the sound of the Left Front, I then marked the position of the gain after satisfied with the tunning. To verify that they are balanced, I sat in driver seat then in passenger seat to test. In driver seat I hear the left speaker sounded a little louder, and in passenger seat I hear the right speaker louder than the left speaker by just the same amount. This tell me they were very much balanced.
To tune the rear speakers, I disconnected the Sub power wire and moved the seat forward. With Fader and Balance controls set to one rear speaker at a time, I tried to fine tune the gains so that the sound pressure of the rear speakers are about 80% to 90% of the front. After all fine tunning were done, I marked the positions of the rear gains. I do the listening test for rear speakers as I did for the fronts, with the driver seat adjusted for normal driving position and the passenger seat at similar position so that both seats will effect the rear speakers the same amount.
Until now, the sound is fairly low because the amp's gain controls were set at about 15%. The next steps were adjusting the amp gains for Front and Rear speakers. You may want to take a break at this time, to start the engine (after open garage door) to re-charge the battery for 10 minutes or so. You do not want to have your battery totally discharged after your stereo had been on for a long time.
After the needed brake, it was time to adjust the amp, after turned off the engine and closed the garage door. This time I turned the HU volume down to 10 and Fader and Balance to Left Front only, then I started turn up the front gain control while listening for noise, I marked the position where I started to hear some distortion, that will be the maximum the Front gain will ever be. I turned it backward by 1 hour (about 30 degree), listened to a few songs to learn what the sound was like for Front Left speaker. I then changed the Balance to Front Right speaker, listening to the same songs to make sure that Front and Rear are still balance with each other. I then sat in the driver seat with both doors closed and listen to more songs to see if anything wrong, after one song, I moved to passenger seat and listen to the same song again. After satisfying with Left and Right balance, I turned up the volume to 15 then to 20 to see how loud they were and to check for noise at higher level. No noise so far, then I turned up the volume to 25 to check for noise and to see how loud at this near maximum level. It was so loud that I had to turn down the amp gain about 1/2 hour (15 degree), this will also reduce the potential noise generated by the amp. The sound is still very loud, but at a more reasonable level and this from only two front speakers. This step is repeated for tunning the rear speakers. After rear speaker gain were adjusted, I changed the Fader to have all four speakers on to check the balance of front and rear, I found that I like it best with front speakers at about 10% to 15% louder than the rears, by adjusted the amp rear gain down a tad.
After Front and Rear speakers are done, I disconnected the rear speaker, re-connected the Bose Sub, adjusted the fader to the Rear only to tune the sub by adjusting the second LOC gain control. I repeated the step above, i.e., Volume was set at 10, adjust the gain until I started to hear distortion, turned down the gain by 1 hour (30 degree), adjusted the fader to listen to music with Front and Sub, I then adjusted the gain of the Sub's LOC to match with the front. Then listen to music at higher volume level at 15, the at 20 and finally at 25. After some listening, I were satisfied with the Sub volume, I then re-connected the rear speakers. Listened to all speakers including the sub, I found that the rear speakers and the sub at this time is a little too loud and it seem to have a very little distortion from the rear, I re-adjusted the gain of the Sub's LOC gain down by 1/2 hour (15 degree) and the amp rear gain the same amount. Re-played the same musics again with both top up and down, door closed, windows up and down, in both seats. With top up I can hear much more bass from the Bose Sub, I had to turn down the rear a little. With top down and with fader adjusted back to center, the total sound were much more balance.
All comments, suggestions and critics are welcome
damn, I gotta learn to read!
Thread Starter
Registered User
Joined: Dec 2003
Posts: 1,774
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From: Irvine, SoCal
Phil, You had so many posts that you can not remember what you did or did not post. I chery picked the ones that I were interest in, save it then more reading, then save more, and so on. After I collect enough infos, I analyze the problem ahead of times and come up with a procedure to attack that problem 
Dave, You're right about set the HU at 70%-75%, but that is for aftermarket HU with preamp outputs, this is how I tune the stock HU that does not have preamp outputs.
Before anything was upgraded, I listen to the stock system very carefully to see at what volume level it will start to produce distortion and noise. I found that for most music, it start to distort with volume set at 30, few songs can make the system distorts at 27, but no distortion at 25 or lower. All this tests were done in garage with door closed and engine off.
I think that the THD+Noise of the stock HU speaker outputs are increased rapidly as volume increase, much more so for the LOC. What I means is it is better to increase the input gains of the LOC with lower volume setting of the stock HU, this way the total THD+Noise of the amplified signals from HU and de-amplified circuit of the LOC will be minimum. Yes, the distortion of the LOC outputs are still more than the pre-amplified signals of most aftermarket HU, but at a low enough level that most people can not detect at higher volume level at highway speed with top down.
So far, I only turned up the volume to 25 on few occasions that I were alone with top down cruising at 90+ MPH on highway, otherwise, I rarely passed 15. This means if I have very clear sound at 20, I will have clearer sound at 15
Dave, You're right about set the HU at 70%-75%, but that is for aftermarket HU with preamp outputs, this is how I tune the stock HU that does not have preamp outputs.
Before anything was upgraded, I listen to the stock system very carefully to see at what volume level it will start to produce distortion and noise. I found that for most music, it start to distort with volume set at 30, few songs can make the system distorts at 27, but no distortion at 25 or lower. All this tests were done in garage with door closed and engine off.
I think that the THD+Noise of the stock HU speaker outputs are increased rapidly as volume increase, much more so for the LOC. What I means is it is better to increase the input gains of the LOC with lower volume setting of the stock HU, this way the total THD+Noise of the amplified signals from HU and de-amplified circuit of the LOC will be minimum. Yes, the distortion of the LOC outputs are still more than the pre-amplified signals of most aftermarket HU, but at a low enough level that most people can not detect at higher volume level at highway speed with top down.
So far, I only turned up the volume to 25 on few occasions that I were alone with top down cruising at 90+ MPH on highway, otherwise, I rarely passed 15. This means if I have very clear sound at 20, I will have clearer sound at 15
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Joined: Oct 2002
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From: Baton Rouge, LA
dang man.... 
you did do some research and definitely worked out a detailed technique. 
i'm flat out impressed, especially based upon your previous experience to this. the only change i might have made in what you did would have been to go straight to 20 to set the amp gains instead of the 15 stop in between. then after backing down a bit on the amp gain, checked the 25 like you did.
i don't tune exactly like this, but actually cheat a bit here and there.
but reading it, i could see how you have derived this from my posts, and have developed your own technique.
well put.
this does make the assumption that the LOC's have a cleaner input than the OEM HU has output... but that wouldn't surprise me if it were true. the one disadvantage of this that i can see is that i've slightly limited your 'steps' of volume control... but the difference between 25 and 28 is really minimal.
after reading all of this -- you really may enjoy that RF HU a lot more than i anticipated.
you did do some research and definitely worked out a detailed technique. i'm flat out impressed, especially based upon your previous experience to this. the only change i might have made in what you did would have been to go straight to 20 to set the amp gains instead of the 15 stop in between. then after backing down a bit on the amp gain, checked the 25 like you did.
i don't tune exactly like this, but actually cheat a bit here and there.
but reading it, i could see how you have derived this from my posts, and have developed your own technique.
I think that the THD+Noise of the stock HU speaker outputs are increased rapidly as volume increase, much more so for the LOC. What I means is it is better to increase the input gains of the LOC with lower volume setting of the stock HU, this way the total THD+Noise of the amplified signals from HU and de-amplified circuit of the LOC will be minimum. Yes, the distortion of the LOC outputs are still more than the pre-amplified signals of most aftermarket HU, but at a low enough level that most people can not detect at higher volume level at highway speed with top down.
this does make the assumption that the LOC's have a cleaner input than the OEM HU has output... but that wouldn't surprise me if it were true. the one disadvantage of this that i can see is that i've slightly limited your 'steps' of volume control... but the difference between 25 and 28 is really minimal.
after reading all of this -- you really may enjoy that RF HU a lot more than i anticipated.
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