[mob17]

this is something that taibanl advised me on so credit goes to him.

if you have an MS-8 and some channels are powered by it and some are amped, the amped channels will be limited by the non amped channels. this is a great work around. there are some instructions that are specific to my set up (e.g gains at 11 o'clock) but generally this can be used by most people:

0.5)
You will do a prelim calibration of MS-8 with gains at the 11 o clock position. (or whatever position is 2v)

1)
When you calibrate ms-8, and you are playing the MS-8 CD, use the hidden menu to find out what volume level gives the OK OK OK display on MS-8...remember it (my car doesn't have a hidden menu so i just remembered 45 clicks)

2)
Set OEM HU at that volume

3)
Go to Test menu of MS-8 (left,right), select pass-thru mode (recommend that you assign your morels (my front mids) to the same OUTPUT channel as the front INPUTS to MS-8)

4)
use pass through mode to play test tone straight to the XD....set the gains according to the JL manual, using a voltmeter

(Dont do this on the bridged center channel...do it for the front channels)...for now leave the center channel gain on minimum.

This will be the MAX gain to which the XD can be set..(i still havent done this as most of the ac voltmeters i have used do not have 1khz in their freq range. once i do it, i will mark this on the amp so i know never to go past this)

5)
MS-8 test menu, select output identification. this is sending unfiltered pink noise through individual channels. i used a db app on my iphone called dB Volume, this has a slow response so is good for measuring. Edit: thanks to Kaigoss. Remember to set amp's LP filter for your underseats to 20-30hz above the ms-8 crossover freq. So if its 200hz then set LP filter to 220-230hz. If you can't do this then set the woofer gains so they are 5db louder than the other speakers

5a)
find the quietest driver in your system (prob rears/ms-8 powered channels)
5b)
turn DOWN the loudest gain to within a few (0-4) dB of rears.
5c)
MATCH the center dB, the front dB, and underseat dB from the driver seat, as closely as you can. (adjust gains on XD)...pay attention to the driver's side SPL, pass side will be a bit softer.

6)
re-run MS-8 calibration at -20 to -25 dB. it can be this high as the amped channels are the same "volume" as the OEM rears. Edit: i have found that the best way for me to get the right calibration volume is to use an SPL app, and after level matching in step 5, adjust the ms-8 vol until the pink noise is 50-55db. Remember the ms-8 volume that gives these readings. This will then give you 5 volumes which you can try.

7)
after final calibration, turn up the gains each by the SAME amount. Edit: This only works if you have only your rears on ms-8 power, as this step will attenuate any ms-8 powered channels. Rears don't bother me too much so its ok for me.

I have used the above method and it sounds brilliant. but i could make it even better by getting more efficient 2 ohm speakers for the rears, so i wont have to turn the gains on the amped channels down that much to match the rears, which in effect means after calibration the gains wont need to be turned up.

[makkan00]

Excellent write up. Few questons in my mind and will ask you.

[kartracer]

Subscribed. On paper for now, I'm piecing together an upgrade for my 2010 E92 base suckeo sound system and the MS-8 will be the heart of it. Let us know how things progress!

Mike

[afsar]

In step 1-4 you seem to set highest undistorted high level for the headunit and amp volume - This ofcourse will be very loud when we are doing it in a residential street, how did you circumvent this? Also what is point in setting highest undistorted volume where they have to be matched to 30-40w each MS-8 channel, they aren't so powerful and all the amps are easily producing 70+ watt per channel. Aren't these steps redundant?

My amp is PDX-4.150, so 150 watt each channel set for 2v could fry the stock L7 speaker, atleast it will be too loud.

What is the idea here, is this understanding right?

1) Get the SPL level from all the speakers same, but in this case what is the use of having extra amplifier as you will have to reduce SPL level to minimum to match non-amped channels.
2) Do driver and passenger seat acoustic calibration after reducing volume a bit - Do you know what volume is best for calibration, I have read it at various threads that reduce your amp gain to 0 to do this calibration, that will undo the first step.

Excuse me for these noob questions.

[mob17]

Originally Posted by afsar

In step 1-4 you seem to set highest undistorted high level for the headunit and amp volume - This ofcourse will be very loud when we are doing it in a residential street, how did you circumvent this? Also what is point in setting highest undistorted volume where they have to be matched to 30-40w each MS-8 channel, they aren't so powerful and all the amps are easily producing 70+ watt per channel. Aren't these steps redundant?

My amp is PDX-4.150, so 150 watt each channel set for 2v could fry the stock L7 speaker, atleast it will be too loud.

What is the idea here, is this understanding right?

1) Get the SPL level from all the speakers same, but in this case what is the use of having extra amplifier as you will have to reduce SPL level to minimum to match non-amped channels.
2) Do driver and passenger seat acoustic calibration after reducing volume a bit - Do you know what volume is best for calibration, I have read it at various threads that reduce your amp gain to 0 to do this calibration, that will undo the first step.

Excuse me for these noob questions.

Regarding playing it in a street its simple, turn the ms-8 volume down and then use the pink noise to set gains. The pink noise is unfiltered so you have to do it at lowish volumes. Obviously you have to ensure that you dont give a speaker too much power. The point of level matching the speakers is that it gives the ms-8 ideal conditions to calibrate and process all that info. You can increase the gains after but obviously this would cause the ms-8 powered channels to be attenuated. So it wouldnt be a good idea if you have a ms-8 powered centre.

I think the best course of action would be:

1) find out at what gain position is the maximum safe gain for each speaker. Either do this by ear or multimeter.
2) level match. So probably means reduce your amp gains to match rears and any other ms-8 powered channels. I think even if you dont reduce the gains, the ms-8 will limit the power of your amped speakers anyway.
3) increase gains to level desired.

In my set up this worked because the only ms-8 powered channels are my rears. So after calibration i can increase my amp gains, with only my rears being attenuated, which i dont really care about. However if you have an unamped centre (which i think you do?) then it would really mess with your front stage if you increased the gains after calibration. So you have 3 options:

1) Level match and leave the gains as they are. This is the best solution if you don't want to add anything else.

2) Get a very efficient centre speaker, like a DLS 424, so its "louder" for a given wattage. So it might even match your amped channels but still running off the ms-8. Even if it doesn't match exactly, it will be louder than what you have, therby reducing the amount you turn your amp gains by.

3) Amp your centre. Might be able to amp your rears for similar prices.

For calibration volume its the same way as i pm'd you. Basically level match with the pink noise in test menu, then using an iphone app adjust the ms-8 volume until you get a 50-55db reading. This will give you a range of 5 ms-8 volumes which you should try.

[kaigoss69]

I would like to add that the underseats have a ~5dB peak at around 300 - 350Hz. So, since the pink noise is full range, the meter will pick-up the level from that frequency range. To get rid of it, it is best to engage the amp's lowpass filter, at about 20-30 Hz above the the MS-8 crossover frequency. So, if you have the underseats/fronts crossed at 200Hz, set the filter to 220 - 230Hz. This way, the level will be set correctly and the MS-8 autotune can function correctly. If you don't have the option of lowpassing the signal, set the gains about 5dB louder than the other speakers.

[mob17]

Originally Posted by kaigoss69

I would like to add that the underseats have a ~5dB peak at around 300 - 350Hz. So, since the pink noise is full range, the meter will pick-up the level from that frequency range. To get rid of it, it is best to engage the amp's lowpass filter, at about 20-30 Hz above the the MS-8 crossover frequency. So, if you have the underseats/fronts crossed at 200Hz, set the filter to 220 - 230Hz. This way, the level will be set correctly and the MS-8 autotune can function correctly. If you don't have the option of lowpassing the signal, set the gains about 5dB louder than the other speakers.

I'll try this as well and see what happens.

[afsar]

Originally Posted by mob17

Regarding playing it in a street its simple, turn the ms-8 volume down and then use the pink noise to set gains. The pink noise is unfiltered so you have to do it at lowish volumes. Obviously you have to ensure that you dont give a speaker too much power. The point of level matching the speakers is that it gives the ms-8 ideal conditions to calibrate and process all that info. You can increase the gains after but obviously this would cause the ms-8 powered channels to be attenuated. So it wouldnt be a good idea if you have a ms-8 powered centre.

I think the best course of action would be:

1) find out at what gain position is the maximum safe gain for each speaker. Either do this by ear or multimeter.
--> Why is this required? As I wrote before most of amp will anyway easily overpower ms-8 amplification
2) level match. So probably means reduce your amp gains to match rears and any other ms-8 powered channels. I think even if you dont reduce the gains, the ms-8 will limit the power of your amped speakers anyway.
--> If this is the case then isn't level matching pointless as MS-8 will anyway reduce the input to the amp automatically matching the level across the car?
3) increase gains to level desired.

In my set up this worked because the only ms-8 powered channels are my rears. So after calibration i can increase my amp gains, with only my rears being attenuated, which i dont really care about. However if you have an unamped centre (which i think you do?) then it would really mess with your front stage if you increased the gains after calibration. So you have 3 options:

--> Yes I have unamped center, no one does 5 or 7 mid-range to high channel amp . Neither I can fit 3 boxes (1 MS-8 and 2 amps) in my E60 However I have exactly the same driver across the car, Stock L7 speakers (and alpine tweeter attached to the centre), they are 2 ohm and think should draw more power from ms-8 then DLS 4 ohm ones. But no way they can match PDX-4.150 150watt channel each, I know 150 watt is a bit of overkill but I didn't have a choice.


1) Level match and leave the gains as they are. This is the best solution if you don't want to add anything else.

2) Get a very efficient centre speaker, like a DLS 424, so its "louder" for a given wattage. So it might even match your amped channels but still running off the ms-8. Even if it doesn't match exactly, it will be louder than what you have, therby reducing the amount you turn your amp gains by.

3) Amp your centre. Might be able to amp your rears for similar prices.

For calibration volume its the same way as i pm'd you. Basically level match with the pink noise in test menu, then using an iphone app adjust the ms-8 volume until you get a 50-55db reading. This will give you a range of 5 ms-8 volumes which you should try.

I am assuming all these needs to be done from driver seat, even the level matching using iphone app, correct? or shall I do it from centre of car which means SPL from all the speaker will same (around centre console)?

Also advise me if Focal KRS/VRS 100 range will help me here (can't afford Morels) to get better result (not that I am complaining with the current setup, it is good, looking for step further), I can source them for around £180ish delivered, worth the money in my setup?

Sorry again for basic questions but I am trying to understand and learn the idea and procedure of level matching not just to follow it for the sake for getting it done.

[mob17]

Steps 1 and 2 are required so it enables you to raise your amp gains after level matching, if required/suitable. It isn't suitable for you as your centre eill be attenuated. And even though the ms-8 will limit the power of amped channels, its still much better for you to level match everything before, you'll get a better autotune.

So you've got 3 L7 mids across the front, and you're amping two of them. So you're going to have to either somehow get a much more efficient centre to match the SPL level of your other 2 L7 mids on ~ 150w of power. Maybe a kappa infinity 42.4? If you're after SQ this won't really be a good idea though. Or you could keep your L7 centre and upgrade to Morels, which are slightly less efficient and also 4 ohm, so they might even match your centre even on 150w. There are online calculators to estimate this. Have a play with different combinations and see what works. You can buy Morels for £230, the extra £50 definately worth it.

I'd measure the SPL levels from the driver head position.

[makkan00]

Originally Posted by mob17

Steps 1 and 2 are required so it enables you to raise your amp gains after level matching, if required/suitable. It isn't suitable for you as your centre eill be attenuated. And even though the ms-8 will limit the power of amped channels, its still much better for you to level match everything before, you'll get a better autotune.

Can I ask few things to gurus here?

Why don't you let MS-8 process its setting and leave it to decided what is best for you? Thats the purpose of it, isn't it?

If you leave it as it is, the drawback is, you will not be able to use morels to its max optimal potential? An I correct in saying that.


So if we go against it, favour Morels' optimal sounding over MS-8 processing and increase Morels gains as you mentioned, are we not defeating the purpose of MS-8?

If I am correct saying what I mentioned above, whichever route we take, we are in loss.

It is basically Processing (SQ) VS Sound (SPL) I guess.


The only best way around is to increase the sensitivity of central speaker or increase its peak power, but then MS-8 can only put through limited watts.

[mob17]

Originally Posted by makkan00

Can I ask few things to gurus here?

Why don't you let MS-8 process its setting and leave it to decided what is best for you? Thats the purpose of it, isn't it?

If you leave it as it is, the drawback is, you will not be able to use morels to its max optimal potential? An I correct in saying that.

So if we go against it, favour Morels' optimal sounding over MS-8 processing and increase Morels gains as you mentioned, are we not defeating the purpose of MS-8?

If I am correct saying what I mentioned above, whichever route we take, we are in loss.

It is basically Processing (SQ) VS Sound (SPL) I guess.


The only best way around is to increase the sensitivity of central speaker or increase its peak power, but then MS-8 can only put through limited watts.

By no means am i a guru, but the optimum autotune is when everythings is level matched. The reason why i can raise my gains after is that all my front stage is amped. So if i can make sure i raise all gains by the same amount, then it doesn't mess with the autotune, apart from the rears, which are attenuated.The rears dont matter to me so i can live with that. If i got more efficient rears, such as infinity kappas, then i wouldnt need to lower the gains of the rest to match them.

If you have a unamped centre speaker which is "quieter" than the rest, then yes you will sacrifice a bit of SPL, as you will f**k up the balance if you raised the gains. But if all the front stage is amped you can have both.

[makkan00]

Originally Posted by mob17

By no means am i a guru, but the optimum autotune is when everythings is level matched. The reason why i can raise my gains after is that all my front stage is amped. So if i can make sure i raise all gains by the same amount, then it doesn't mess with the autotune, apart from the rears, which are attenuated..

That make sense if you have central amped.

[afsar]

If all the speakers are amped how would you level match? Is this even needed?

FYI, there are two amp here powering all set, Alpine PDX-4 powering front door card and underseats and PDX-5 powering rest, all L7 speakers, underseats Jehnert, boot sub JL W6 (which is powered by PDX-5 mono).

What will steps for level matching in general?

Note: I am working in stages, next step will be to install Morel Hybrids in the front door cards.

[mob17]

Its all in the first post. Only difference is your rears may not be the quietest, which only means you'll have to turn down other gains.

Basically set the gains to the correct position (at 2v or use a DMM), then turn down the "louder" gains to match your quietest ones. Remember when you play pink noise to level match use a volume of -25db or lower.

After everything is matched, my advice would be find the MS-8 volume where the SPL is 55db (using the same method as above). Then use that as the calibration volume. If that doesnt sound right work down to 50db.

[afsar]

thanks a lot, I will give it a go.

[afsar]

After long time I revisited MS-8 tuning and must say it has made a huge difference. I am not confident of what I have done is right or not but sound boominess is almost gone.

I wanted to do upgrade step by step, laziness has caused gaps between to widened a bit too much now First I have installed rear sub which was too boomy then installed Jehnert underseats still boominess was there. Even after re-calibration (subsonic 20Hz, JL 12W6 LP 80Hz 12dB/oct, Jehnert 200Hz 24dB/oct, rest all to stock L7 speakers and tweeters) boominess was present. Today I tried to level match (must admit for the first time), only my front door card and underseats are amped. Stock L7 amp and tweeter in rear parcel shelf were too low to reduce amp gain and I couldn't match it to them. Also center channel (powered by MS8, again stock L7 with added tweeter) was too loud (compared to rear) so couldn't level match from front to rear. So decided to level match among front stage, This is what I did:

I reduced MS-8 volume to -22
Played test tone from output identification to the center channel
Measured center using Sound meter app on my Nexus 7
I had to increase gain on my PDX4.150 almost to 10'o clock position on amp to match door card's speakers with the center.
Then I matched the underseats and for that I had to increase the gain to 12 o'clock position.

After a while I reduced MS-8 volume to like -34 and then checked fronts were still matching but underseats were low, for that I had to increase gain even further to something between 2-3 o'clock position.

Then I recalibrated driver seat. I wasn't getting good feel on such a high gain for the underseats so I reduced it to 12 o'clock position after the calibration.

Sound is better then before, atleast boominess is much low now.

I will keep testing it for few more days and report back if I like it this way.