My first car audio DSP processor is JBL MS-8.
It was a huge rave in diymobileaudio.com, with quite many threads and the MS-8 official thread page count by the time of this writing........627 pages.
The thread itself started Jan'07 and still active till now (March'20, 12k+ posts to date)... less and less post, of course.
Well... with a new car in '13, I enthusiastically bought MS-8......... MS-8 DIYMA thread did hell of a job of getting me to part with my money for MS-8 :).
Auto tune, 8 channels (thinking to expand to 3 way), powered output (for rears/center simplicity), Radio Frequency (no need to point the remote) remote control, etc..... Then, MS-8 it is!
After long and exhausting web search, numerous calls to numerous car audio shops.... for the ultimate reason of getting the lowest price in the whole wide world if possible.
Finally bought from an independent guy (forgot his name). Initially also bought along a Morel Tempo sets for my wife's car. Unfortunately, the one he brought to me seems a bit mess. Some glue splatter in the cone, and I thought he brought me a fake one. I emailed Morel to check the SN, and it was legit. Contacted him again to buy it...already sold and he ran out of stock, but I still seal the deal on MS-8 with him.
Deal was done by numerous SMS chats. YES, short messaging services. This is before Whatsapps/BBM/ etc time. Only chat application i recall was Yahoo! Messenger which was ceased service a couple of months ago.
JBL MS-8..... hmmmm...... revolutionary OEM integration processor with AUTOTUNE! Yuuuummmmmmy!!!
Autotune.... why? I recall my first time attending IASCA contest in my country, around early ninetees. That was the first IASCA contest in this country. A honorary judge was a foreigner named Craig .......
With IASCA, RTA measurement is mandatory and I also a believer of good sound always shows in measurement.
In my assumption, with autotune, I could skip of needing to have an access to a RTA.
So, with all equipment installed, then let's pull the autotune trigger.... should be a piece of cake, right?
Half way true.
Basically, the MS-8 autosetup/calibration routine (output setup) are defining operation mode (2 ways, 3 ways, subs, rear, front, center channels combination) to suit the design goal.
2 way front + sub, tweeter high pass at 2.5KHz, midbass bandpass 65Hz to2.5KHz, sub @ 65Hz, all with Linkwitz Riley 4th order .... what's so difficult about that? :) Can always tweak them in very near future :))
Later on I learned from DIYMA (the great Mr. Wehmeyer), in general, it is better to cut subs at 80Hz for MS-8 (because of the way MS-8 autotuning algorithm?)
Also it is recommended to factory reset after several calibration. Perhaps to clear the memory/processor, since indeed this is a computing device.
There is also an Input Setup routine that MS-8 use to de-eq, de-time align & setting headunit before clipping volume of an OEM system with multiple outputs.
Once I realized the purpose of input setup routine (I'm using aftermarket headunit, with only R & L outputs), I always skipped this routine.
Next, assign corresponding channel to suit installed drivers & setting the crossover orders & cut off frequency.
After that, the real autotune routine starts, by first setting the main volume control -20 to -40 depending if the installation using external or internal amp. Next step are some test tones (MLS?) for time alignment & AutoEQ. These are repeated for several seating position.
During AutoEQ measurement, seems MS-8 is smart enough to do spatial averaging of each measurement. By wearing Binaural Mic in the form of cheap economy class airplane free headsets... it measures 6 position in each measurement.
The person wearing the mic need to look forward and turn to left and right rearview mirrors......... kind of neat, isn't it?
Afraid to get lost in the middle of the path? Not sure to look left or look right? Just take a glace to the display, it will point you to the right direction. Right on, MS-8!
Btw, in a few instance i tried to cheat the MS-8.... only straight front position during the measurement :)
What's next? Anything else? That's it? You sure? No.... last step is unplugging the Binaural mic from the MS-8.
If left plugged, according to some, may cause some feedback problem that could destroy unprotected tweets/aeroplane noise of death. It is recommended to install series capacitor (large value, around 60uF if my memory serve me right, so it acts as an all pass filter and won't interfere with tweeter cut off frequency) to protect those teenie weenie voice coils, in case shit happens, say amp turn pop, wrong channel assignment, etc.
Lucky me, in many years of my MS-8 sevice, never one this problem occured.
And that it. Now, let's hear the magic of your revolutionary OEM Integration Processor JBL MS-8, after setting the main volume to about -6 to -9.
Another assumption is... the autotune uses JBL target curve... so the FR must be good, sound must be good, the "Correct Sound", at least according to Harmann.
The first song from my new car with new JBL MS-8 and new audio gears.... well, some are from previous installation.... sounded just like an ALARM CLOCK RADIO ....... Don't ask what it is..., again, sounded exactly like an ALARM CLOCK RADiO.
HOWEVER.......I observed that.... the CENTER IMAGE.....it was like something I never heard in a car before.........very slightly to the left side of the dash but it was TACK SHARP! Maybe I'm exagerating, thus, safely said the center image may be only 1 or 1 1/2 notch below the one you find in a good pair of headphones. Afterall, this is an automobile environment :)
This might be the result of precise time alignment and L/R frequency response uniformness (FR for short).
Maybe MS-8 has a finer time alignment resolution, since I could never experienced center image like this in previous device with time alignment capability (alpine CDA-9833 and Clarion DXZ-776).
Later, I found a way to correct this during the time alignment routine, that is not to look straight to the front, but just a slight tilt a bit to the center rearview mirror.
This method gave a tack sharp center image in the center of the dash, well least this method works in my car, my system & my ear :) I may have difference hearing in my left and right ear :) :) :)
I believe this was the point I boarded on to the car audio long haul long hour journey. All starts with alarm clock radio sound.
Again... back to 400+ of diyma pages to look for some install tips & trick. Some of them, re-check all driver polarity & set to normal, adjusting all amplifier gain to 2 volts, skips the input setup, flipping sub polarity during setup, change input from default to aux and lots lots of different tips and trick from DIYMA.
Mentioned above, I tried only straight front position only, thinking maybe the measurement variation could be too great and screw the algorithm.
Weeks of tweaking and running numerous calibration, I can only manage to get a good center image but unlistenable tonal balance.
Fortunately there is also manual graphic EQ, tone control & sub volume setting, with these, I was able tune the system to a decent sound quality.
Coming months, & moving forward to get the autotune right, I bought a Behringer ECM8000 condenser measurement microphone, a mixer to connect it with my laptop souncard and try to setup a PC RTA platform.
Not satisfied, then I invested on a handheld RTA (Phonic PAA3). I assume (again) maybe with RTA i could find what was wrong (FR standpoint, maybe some extreme peak/cancellation that prevents autotune to complete it's job).
Well, I spotted around 2.5Khz cancellation with my speaker set or installs (vifa P17WJ & small vifa xt25)... Great! I just found a solid reason to shop more :)))
So....the replacement is.......drumroll...........Audison AV K6 sets.
Why Audison? Maybe i share the reason in future posts ;)
Ha ha.... better sounding sets, at least to my ears.
However, still, no luck with autotune here. Another autotune dead end :((
However with several RTA systems, different softwares & speaker sets to play with, I guess, I was developing experience to tune with RTA, say matching L/R FR, applying target curves, smooth out some FR irregularities, tweak crossover points/slope, etc.
Back to autotune.........So much for MS-8 AUTOTUNE, huh?
YES, it is for ME/MY system/MY installation. And until I replace MS-8 with another processor (5-6 years in service), I never once could get a good sound without heavy tuning with those manual settings available.
But hey....... there are so many praises for MS-8 in many forums, so many success stories with MS-8. So how come I just can't achieve the same as others?
I never found the exact problem & answer within my system. Should MS-8 have the capability to give some feedback of why the autotune cannot come to completion, that would be marvellous.
So then, is MS-8 a bad DSP?
DEFINITELY ABSOLUTELY NO.
MS-8 is a GREAT product. Great implementation of a great concept. Could be improved? Hell sure...too bad it was discontinued.
While it did not work as expected in my system, is a different story.
To me, MS-8 is another form of computational product. Say, analogy to a 8 digit calculator, you just simply cannot solve 9 or 10 digit of math problem with it. All computational product have a limit in their computing power. It WILL do the job perfectly as long as the problem DOES NOT exceeds its capability.
Maybe my system & my next to nothing installation skills just somehow creates an 20 digit problem that is beyond the capability of MS-8.
And still, I managed to get a decent sounding system with MS-8, with (maybe) half complete autotune.
Some feature of MS-8 I haven't tried yet, one of them is center channel with L7.
After 5-6 years... it seems no more to tweaķ and I put MS-8 on retirement plan.
Simple reason. No tweak no fun. Cheers!!!
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