[afsar]

I am not listening on higher volume, probably 20% of max all the time. At times higher, but for short duration.

I have found MT-23 to be most detailed tweeters, Morel set overall very good. You know what, when I replaced L7 with Morel without any calibration or change it was sounding very very very nice.

Then I level matched it and found that it was level matching with PDX-4.150 with center (Xtant coaxial driver) on lower gain (quarter) which was higher in case of L7 (a bit less then half) on the pdx gain knob. I thought morels will take more wattage to produce the same spl as L7 given L7 was 2 ohms, unless I am doing something wrong.

Also it doesn't sound "as good" as before level matching and MS-8 calibration. I am not complaining but quality was better prior to calibration.

[makkan00]

Originally Posted by afsar

Also it doesn't sound "as good" as before level matching and MS-8 calibration. I am not complaining but quality was better prior to calibration.

Afsar
Have you changed your xover from 200Hz to different value during the calibration?

[makkan00]

Originally Posted by afsar

Then I level matched it and found that it was level matching with PDX-4.150 with center (Xtant coaxial driver) on lower gain (quarter) which was higher in case of L7 (a bit less then half) on the pdx gain knob. I thought morels will take more wattage to produce the same spl as L7 given L7 was 2 ohms, unless I am doing something wrong.

Please do not forget that output voltage of MS-8 (through RCA) differs if you calibrate again base on
- your gains on the amp
- Whether you are using the central speaker through MS-8 / or being amped
- Type of speakers / amp

So considering that, your gains on the amp would be different, unless you keep all the factors same.

[afsar]

Does this mean level matching is not worth doing?

[afsar]

Originally Posted by makkan00

Afsar
Have you changed your xover from 200Hz to different value during the calibration?

Yes I changed it from 200 to 150.

[makkan00]

Originally Posted by afsar

Does this mean level matching is not worth doing?

My answer to that is YES. It is not worth of doing it.
But we all are different and we think differently. Logically, I did not get a reason for level matching.

[makkan00]

Originally Posted by afsar

Yes I changed it from 200 to 150.

Thats where the change is I guess.
At 200hz speaker is hardly dispensing any mid bass and on 150hz you are having some midbass.
Other than that, what volume level of ms-8 have you used during the calibration and what volume level of ms-8 are you using after calibration changes different things.
200hz frequency is too quiet for your morels. 150hz or 125hz is far better and it brings your sound stage up in front of you.

[kaigoss69]

Well you still want to level match, as good as you can. Any channel driven by the MS-8 becomes the baseline. You need to try to bring the levels of the other externally amplified speakers down as much as possible to match the base line channel(s).

[makkan00]

Originally Posted by kaigoss69

Well you still want to level match, as good as you can. Any channel driven by the MS-8 becomes the baseline. You need to try to bring the levels of the other externally amplified speakers down as much as possible to match the base line channel(s).

Kaig
Are you referring to level match pre-calibration or post calibration of MS-8?

[kaigoss69]

Originally Posted by makkan00

Kaig
Are you referring to level match pre-calibration or post calibration of MS-8?

Pre-calibration. Post calibration level matching should only be necessary for midbass and subwoofer channels.

The pre-cal level setting procedure I use is as follows:

- sit in passenger seat
- position microphone in driver head position (spot between ears), pointing at ceiling. You can hold by hand or fixate to head rest. I use iPhone RTA app with external mic but internal one also works well for this purpose.
- go into the "secret" menu (hold "left" button on remote 3 seconds, then "right" button 3 seconds, then "left" again until the menu appears.
- choose "output identification", this plays pink noise through each channel. Make sure MS-8 volume level is turned down, at least -25dB.
- play pink noise for CH1 and adjust MS-8 volume to reach at least 75dB
- record the output of each channel (don't touch MS-8 volume again)
- then use amp gains to match channels as closely as possible, within 2-3dB
- subwoofer channel is different, set amp gain to min. and listen to sweep volume during calibration. You should be able to hear the sweep, but definitely not feel it!
- exit secret menu and recalibrate

[afsar]

Originally Posted by kaigoss69

Pre-calibration. Post calibration level matching should only be necessary for midbass and subwoofer channels.

The pre-cal level setting procedure I use is as follows:

- sit in passenger seat
- position microphone in driver head position (spot between ears), pointing at ceiling. You can hold by hand or fixate to head rest. I use iPhone RTA app with external mic but internal one also works well for this purpose.
- go into the "secret" menu (hold "left" button on remote 3 seconds, then "right" button 3 seconds, then "left" again until the menu appears.
- choose "output identification", this plays pink noise through each channel. Make sure MS-8 volume level is turned down, at least -25dB.
- play pink noise for CH1 and adjust MS-8 volume to reach at least 75dB
- record the output of each channel (don't touch MS-8 volume again)
- then use amp gains to match channels as closely as possible, within 2-3dB
- subwoofer channel is different, set amp gain to min. and listen to sweep volume during calibration. You should be able to hear the sweep, but definitely not feel it!
- exit secret menu and recalibrate

I think above given procedure is going to be useful ONLY if a few channels (like center and rear) is driven by MS-8 directly. If all channels are going to be amped then set gain at max undistorted point at the amp and then calibration should help. Am I right?

[kaigoss69]

Originally Posted by afsar

I think above given procedure is going to be useful ONLY if a few channels (like center and rear) is driven by MS-8 directly. If all channels are going to be amped then set gain at max undistorted point at the amp and then calibration should help. Am I right?

Nope. Your starting point should be the 2V gain setting for the amp driving the front L+R highs. Then match all the other channels to those. You want to keep the best possible S/N ratio through the chain. Theoretically, at 2V the amp gain is set correctly to produce max. output with the MS-8's max output (2V). However, not all channels will be equally loud if you max out all the gains. Just set to 2V and calibrate. Now turn up the MS-8 vol. to -6dB and your HU to max. undistorted level. If it is still not loud enough you can re-set the gains a little higher and recalibrate, but always make sure the levels are matched.

If you do not level match then the MS-8 processing power may not be enough to make the necessary corrections, and you may end up with an unfinished calibration, and unwanted distortion.

[makkan00]

Originally Posted by kaigoss69

Pre-calibration. Post calibration level matching should only be necessary for midbass and subwoofer channels.

The pre-cal level setting procedure I use is as follows:

- sit in passenger seat
- position microphone in driver head position (spot between ears), pointing at ceiling. You can hold by hand or fixate to head rest. I use iPhone RTA app with external mic but internal one also works well for this purpose.
- go into the "secret" menu (hold "left" button on remote 3 seconds, then "right" button 3 seconds, then "left" again until the menu appears.
- choose "output identification", this plays pink noise through each channel. Make sure MS-8 volume level is turned down, at least -25dB.
- play pink noise for CH1 and adjust MS-8 volume to reach at least 75dB
- record the output of each channel (don't touch MS-8 volume again)
- then use amp gains to match channels as closely as possible, within 2-3dB
- subwoofer channel is different, set amp gain to min. and listen to sweep volume during calibration. You should be able to hear the sweep, but definitely not feel it!
- exit secret menu and recalibrate

Kaig
I have tried this in the past and no difference at all. I do not understand the reason of doing it, as thats MS-8 job. May be I am missing something.
I get the best results, if keep the amp gains at 2V input and calibrate.

[afsar]

How do I know where is 2V if it is not labelled on the amp gain knob? What is best way to level match (pre and post) if all the channels are amped?

[makkan00]

Originally Posted by afsar

How do I know where is 2V if it is not labelled on the amp gain knob?

If its not on the amp, then you cannot do that. Unless the amp is JL and usually there manual suggest it in clicks.

Originally Posted by afsar

What is best way to level match (pre and post) if all the channels are amped?

You could experiment level matching pre calibration and then calibration without level matching. I had no difference in the sound.

Post calibration level matching is not a true term. It is basically adjusting the gains of the amp(s) as per your taste. One example is increasing the gains of mid bass drivers.

[kaigoss69]

Originally Posted by makkan00

Kaig
I have tried this in the past and no difference at all. I do not understand the reason of doing it, as thats MS-8 job. May be I am missing something.
I get the best results, if keep the amp gains at 2V input and calibrate.

Think of what the processor has to do. The summed, unprocessed output of your speakers is naturally going to look like a jagged curve, with plenty of dips and rises. Since we are not using the same speakers, the same amplification, and don't have the same distance/exposure to all the speakers in the car, the summed response in the listening position will not be flat. Also, the speakers themselves have non-flat responses. The processor - among other things - has to smooth out that curve and try to make it look like the pre-programmed JBL target curve. Now, the processor only has a certain degree of EQ headroom, before it runs out of steam. Therefore, the closer the unprocessed response curve is to the target curve, the less EQ is required.

So if you have a very "bad" unprocessed response curve, it is very possible that the processor will not have enough EQ hearoom available to make the necessary changes. In such a case you have two problems: 1) The target curve is unfinished so it will not sound "right". 2.) The gains on the processor are likely maxed which means it will distort easier.

If, on the other hand, you have a good (i.e. level-matched) unprocessed response curve, the processor will likely not run out of steam, achieve the target curve, and you will likely have some headroom left to achieve a better/higher unclipped output to the amps.

Since you feel there is no difference in the final sound between doing pre-cal level-matching and not, that tells me that in your case the processor is still able to achieve the same target curve in both cases. So YOU probably didn't need the level-matching.... but how do you know without trying???

I still believe the processor can achieve a higher unclipped output the better the pre-calibration curve is, so I think there is benefit to doing it just for that reason alone.

By the way, I have experienced what an unfinished calibration can sound like, and I am glad I kept going and didn't leave it there.

[makkan00]

Originally Posted by kaigoss69

Since you feel there is no difference in the final sound between doing pre-cal level-matching and not, that tells me that in your case the processor is still able to achieve the same target curve in both cases. So YOU probably didn't need the level-matching.... but how do you know without trying???

I still believe the processor can achieve a higher unclipped output the better the pre-calibration curve is, so I think there is benefit to doing it just for that reason alone.

What you have said, its a good theory. Without knowing that we think similar at some stage, I had gone for hi-fi coding. Which takes out the eq'd sound out of the equation and less processing for the processor.

I have done the level matching prior to calibration and heard the sound for 2-2.5 hours, and later I re-calibrated it without level matching.
Virtually no difference.

No sure if it has to do with hi-fi coding though....

[afsar]

I have coded my car also to the hifi so hope it helps.

Now the biggest challenge I have is get rid of the boominess of W6 as it is causing headache. Someone suggested to feed sub input from front low (shared between underseat and rear sub) and use amp gain and filter to run the sub.

Wondering how is MS-8 going to cope with this? Won't its autotuning algorithm which adjustes the sound latency get confused due to massive location variation (boot verses front underseat) at the source of sound? How to level match this setup?

[kaigoss69]

Originally Posted by afsar

I have coded my car also to the hifi so hope it helps.

Now the biggest challenge I have is get rid of the boominess of W6 as it is causing headache. Someone suggested to feed sub input from front low (shared between underseat and rear sub) and use amp gain and filter to run the sub.

Wondering how is MS-8 going to cope with this? Won't its autotuning algorithm which adjustes the sound latency get confused due to massive location variation (boot verses front underseat) at the source of sound? How to level match this setup?

The MS-8 does not time align to the sub, so the distance does not matter much. Before you try the other mod, try putting the sub box in the back seat during calibration. Turn the sub gain all the way down. After calibration put the box back in the trunk. See if that took care of the boominess.
If the sub is in a corner enclosure, reverse the polarity, this also helps. When you put it in the back seat for calibration, put it in normal polarity, then reverse again when you put it in the trunk.

If the results of this are not satisfactory, try the other mod you mentioned. It can work very well.