Please help with optimizing system (MS-8) - Camaro5 Chevy Camaro Forum / Camaro ZL1, SS and V6 Forums

gnvlettuce · 09-17-2012, 05:58 PM

This is my first attempt at building a great system and I could use some help optimizing this thing. I have a limited knowledge of car audio but I'm learning as I go along. When I started, I truly had zero knowledge. Anyway, I have the stock HU, JL C2650 component speakers in the front doors, JL TR690-TXi 6x9s in the rear deck, JL XD 400/4 amp mounted in the trunk, JL JX500/1D amp mounted on the back of the rear seats, 2 10" JL subs in custom enclosure, and JBL MS-8 mounted in the trunk. I have run the calibration for the MS-8 countless different ways and it isn't really that close to sounding right. It has flashes of brilliance, but nothing sustained. Let me explain.

With the all the crossover points set close to what the JBL booklet recommends, the front tweeters get absolutely horrible distortion with high notes at any volume above what you could easily talk over. I tried setting the crossover points all kinds of ways and it didn't really affect this at all. I adjusted the gains and noticed mild improvement but only when I had the front gains turned nearly off. I then disabled Logic7 and even at 40-50% gains it significantly reduced but did not solve the problem. It is still obvious at very loud volumes and when you shift the fader all the way up then it becomes even more obvious. The only way to get rid of it almost entirely is to set the gains to 0, adjust fader to about 3 notches to the rear, and turn off Logic7. I have a feeling that this shouldn't be necessary.

I have spent way too much time and money on what is seeming like a bottomless pit with sound that is occasionally awesome but then gets all distorted. Given what I have physically installed in the car, is it not unreasonable to expect to be able to crank this thing up to near concert level volume and hear great sound? Please help!

darkrider01 · 09-17-2012, 10:49 PM

I'll help the best I can. The MS-8 is a wonderful, wonderful device. it can be a beast if you get something wrong though.

Let me start with a few basics.

1. Did your car come with the Boston system?

2. How do you have the MS-8 connected to your head unit?

3. Did you retain your center channel (if you had one)?

4. Are you 100% sure you set your inputs and outputs up properly (I had my rear channels switched my first time - I corrected it during setup).

5. Have you tried 24db octaves?

6. What are you using to control volume - the MS-8 or your head unit? I had best results turning the MS-8 up to max and using my head unit to control system volume.

These are assumptions I am making - is it possible you may have misunderstood some of the directions?
1. You set your output channel 1 and 2 as front (your JL C2650's), 1 way, High-pass, 80Hz, 24db
2. You set your output channel 3 and 4 as side (your JL TR690-TXi 6x9's), 1 way, High-pass, 80Hz, 24db
3. You set your output channel 5 to sub (single because you have a mono-amp), 20Hz, 24db, 80Hz

One note: I would start my system will all gains set to 0. If it doesn't get loud enough to you after setup, I would set the gains to 50% and start over. When I was running my MS-8 (I had all gains at 0%), I could crank the volume to 100% and it was loud and crystal clear, with no distortion. It sounded like a concert on my dash.

TeamTCA · 09-18-2012, 09:15 AM

There are several variables on setting up ANY MS-8. It does great things in a short amount of time but it takes almost always several times to set it up and adjust amp gains EVERY TIME. I have done prob 7 or 8 units myself and it is always the same. Not knowing exactly how you have everything set up currently, keep these things in mind:

1. Approx 1/3 on all amp gains (you will have to adjust later)
2. Never go above -10 on MS-8 volume during setup (usually -20 to -15)
3. Deck volume is irrelevant during setup as everything is setup & tune is produced from the MS-8 itself (freq sweeps- these should not be very loud either during setup- audible but not very loud, especially the subbass)
4. Not necessary to setup both front seats but is better and DOES make a difference with a second person/passenger in the car- So easier with another person in the car.
5. Typical setup will usually result in NO midbass & subbass will not sound correct either until you adjust amp gains. Most important thing to understand is that once you adjust any amp gain AND THEN RE-SET UP the output levels WILL CHANGE AGAIN. Everytime you re-setup the MS-8 you will have to re-adjust amp gains- a real pain in the ass.
6. The MS-8 tries to adjust any system EQ/Tune to a preset "target curve". This is only possible with decent drivers and good setup. It is capable of doing a lot but it does not do miracles.
7. The unit really needs "rear fill"- preferable set up as "SIDE" to operate correctly. The center channel option also works well but is much better with a larger format driver in the center- not really possible in a Camaro. May want to try setup WITHOUT center speaker at all. But REAR is very important. When you go thru menu and select your particular spkr arrangement it will intentionally remove certain freqs from the front drivers and send to the center and also the rear spkrs. Very important to understand how this device works.

Your "distorted at a reasonable volume" comes from clipped signal from the headunit BECAUSE the MS-8 volume level was probably set TOO HIGH when you did the setup. Try lowering it -20 or -15. Remember, you should hear all the freq sweeps during setup but none should be overbearing or too loud. If they are then turn down amp gains. Start at around 1/3 gain on amps and go from there. Once you set everything up you can make small tweaks on the eq. Also, I have found that in most cases, you will need to lower the "MID" gain in the preamp section of the MS-8. THis will help a lot by itself. Stay away from the "SUB LEVEL" also. With your setup it will only make it sound worse, as the unit does not actually increase the SUB only output gain like you would think, but rather increase ALL low frequencies below 100Hz which will affect your front spkrs also.

Once everything is setup properly, then turn the MS-8 main volume ALL THE WAY UP and use the deck volume from then on. No need to adjust after that. You may have to tweak amp gains but will be very minor.

I hope this was of some use to you. Just bear with it. It will get better. It just takes some trial and error to get it right. Let us know if this helps....

gnvlettuce · 09-18-2012, 05:48 PM

Thanks guys for replying. I took a lot of your advice and got the clipping to at least reduce a little bit, but I still wasn't happy. I then started actually looking at the devices and how they were installed as I had a shop do most of the work. They had 2 of the RCA cables reversed on the MS-8. Once I fixed that and recalibrated, there is just about zero clipping. I think I have established a cause and effect relationship here, but tell me if this doesn't seem plausible because I may have inadvertently done something else that is responsible for the improvement. Thanks again, everyone.

09-17-2012, 05:58 PM	#1
gnvlettuce Drives: Camaro 1LT RS Join Date: Sep 2010 Location: GNV FLA Posts: 6	Please help with optimizing system (MS-8) This is my first attempt at building a great system and I could use some help optimizing this thing. I have a limited knowledge of car audio but I'm learning as I go along. When I started, I truly had zero knowledge. Anyway, I have the stock HU, JL C2650 component speakers in the front doors, JL TR690-TXi 6x9s in the rear deck, JL XD 400/4 amp mounted in the trunk, JL JX500/1D amp mounted on the back of the rear seats, 2 10" JL subs in custom enclosure, and JBL MS-8 mounted in the trunk. I have run the calibration for the MS-8 countless different ways and it isn't really that close to sounding right. It has flashes of brilliance, but nothing sustained. Let me explain. With the all the crossover points set close to what the JBL booklet recommends, the front tweeters get absolutely horrible distortion with high notes at any volume above what you could easily talk over. I tried setting the crossover points all kinds of ways and it didn't really affect this at all. I adjusted the gains and noticed mild improvement but only when I had the front gains turned nearly off. I then disabled Logic7 and even at 40-50% gains it significantly reduced but did not solve the problem. It is still obvious at very loud volumes and when you shift the fader all the way up then it becomes even more obvious. The only way to get rid of it almost entirely is to set the gains to 0, adjust fader to about 3 notches to the rear, and turn off Logic7. I have a feeling that this shouldn't be necessary. I have spent way too much time and money on what is seeming like a bottomless pit with sound that is occasionally awesome but then gets all distorted. Given what I have physically installed in the car, is it not unreasonable to expect to be able to crank this thing up to near concert level volume and hear great sound? Please help!

09-17-2012, 10:49 PM	#2
darkrider01 Aural Assault Vehicle Drives: 2010 IBM 2SS/RS, 2015 Sierra Denali Join Date: Jun 2011 Location: Garner, NC Posts: 792	I'll help the best I can. The MS-8 is a wonderful, wonderful device. it can be a beast if you get something wrong though. Let me start with a few basics. 1. Did your car come with the Boston system? 2. How do you have the MS-8 connected to your head unit? 3. Did you retain your center channel (if you had one)? 4. Are you 100% sure you set your inputs and outputs up properly (I had my rear channels switched my first time - I corrected it during setup). 5. Have you tried 24db octaves? 6. What are you using to control volume - the MS-8 or your head unit? I had best results turning the MS-8 up to max and using my head unit to control system volume. These are assumptions I am making - is it possible you may have misunderstood some of the directions? 1. You set your output channel 1 and 2 as front (your JL C2650's), 1 way, High-pass, 80Hz, 24db 2. You set your output channel 3 and 4 as side (your JL TR690-TXi 6x9's), 1 way, High-pass, 80Hz, 24db 3. You set your output channel 5 to sub (single because you have a mono-amp), 20Hz, 24db, 80Hz One note: I would start my system will all gains set to 0. If it doesn't get loud enough to you after setup, I would set the gains to 50% and start over. When I was running my MS-8 (I had all gains at 0%), I could crank the volume to 100% and it was loud and crystal clear, with no distortion. It sounded like a concert on my dash. __________________ My amplifier pop/click/thump solution thread Power Mods * K&N Typhoon CAI, Flowmaster American Thunder cat-back exhaust, Hurst Short Throw Shifter Exterior Mods * Black Phantom Grille * 22" T.I.S. 537MS wheels w/ Nitto INVO rubber * OEM body kit Suspension Mods * BC Racing Coilovers * Lakewood Strut Tower Brace Audio Mods * Stinger SPP 2250 Battery * Mosconi 6to8v8 w/ RCD * Pioneer AVH-X7500BT * Scosche Dash Kit * 2 - Mosconi AS200.4 * 2 - JL Audio 13W6v2 * Focal 165KRX2 Power (active) * Mosconi Gladen One 240.2 * Rockford Fosgate Power T1692

09-18-2012, 09:15 AM	#3
TeamTCA Drives: 2010 Camaro 1SS/RS #21068 Join Date: Apr 2009 Location: Benton, Arkansas Posts: 91	There are several variables on setting up ANY MS-8. It does great things in a short amount of time but it takes almost always several times to set it up and adjust amp gains EVERY TIME. I have done prob 7 or 8 units myself and it is always the same. Not knowing exactly how you have everything set up currently, keep these things in mind: 1. Approx 1/3 on all amp gains (you will have to adjust later) 2. Never go above -10 on MS-8 volume during setup (usually -20 to -15) 3. Deck volume is irrelevant during setup as everything is setup & tune is produced from the MS-8 itself (freq sweeps- these should not be very loud either during setup- audible but not very loud, especially the subbass) 4. Not necessary to setup both front seats but is better and DOES make a difference with a second person/passenger in the car- So easier with another person in the car. 5. Typical setup will usually result in NO midbass & subbass will not sound correct either until you adjust amp gains. Most important thing to understand is that once you adjust any amp gain AND THEN RE-SET UP the output levels WILL CHANGE AGAIN. Everytime you re-setup the MS-8 you will have to re-adjust amp gains- a real pain in the ass. 6. The MS-8 tries to adjust any system EQ/Tune to a preset "target curve". This is only possible with decent drivers and good setup. It is capable of doing a lot but it does not do miracles. 7. The unit really needs "rear fill"- preferable set up as "SIDE" to operate correctly. The center channel option also works well but is much better with a larger format driver in the center- not really possible in a Camaro. May want to try setup WITHOUT center speaker at all. But REAR is very important. When you go thru menu and select your particular spkr arrangement it will intentionally remove certain freqs from the front drivers and send to the center and also the rear spkrs. Very important to understand how this device works. Your "distorted at a reasonable volume" comes from clipped signal from the headunit BECAUSE the MS-8 volume level was probably set TOO HIGH when you did the setup. Try lowering it -20 or -15. Remember, you should hear all the freq sweeps during setup but none should be overbearing or too loud. If they are then turn down amp gains. Start at around 1/3 gain on amps and go from there. Once you set everything up you can make small tweaks on the eq. Also, I have found that in most cases, you will need to lower the "MID" gain in the preamp section of the MS-8. THis will help a lot by itself. Stay away from the "SUB LEVEL" also. With your setup it will only make it sound worse, as the unit does not actually increase the SUB only output gain like you would think, but rather increase ALL low frequencies below 100Hz which will affect your front spkrs also. Once everything is setup properly, then turn the MS-8 main volume ALL THE WAY UP and use the deck volume from then on. No need to adjust after that. You may have to tweak amp gains but will be very minor. I hope this was of some use to you. Just bear with it. It will get better. It just takes some trial and error to get it right. Let us know if this helps.... __________________ Kenwood Excelon, Rockford Fosgate, JBL, Hertz, Audison, Illusion Audio, Mosconi, Diamond Audio, Hybrid Audio, WetSounds, & more

09-18-2012, 05:48 PM	#4
gnvlettuce Drives: Camaro 1LT RS Join Date: Sep 2010 Location: GNV FLA Posts: 6	Thanks guys for replying. I took a lot of your advice and got the clipping to at least reduce a little bit, but I still wasn't happy. I then started actually looking at the devices and how they were installed as I had a shop do most of the work. They had 2 of the RCA cables reversed on the MS-8. Once I fixed that and recalibrated, there is just about zero clipping. I think I have established a cause and effect relationship here, but tell me if this doesn't seem plausible because I may have inadvertently done something else that is responsible for the improvement. Thanks again, everyone.