Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
07956 Sound Minor Always Apr 28, 2021, 05:43 May 22, 2021, 21:49
Tester Alex7 View Status Public Platform MAME (Official Binary)
Assigned To aaron Resolution Fixed OS Windows 10 (64-bit)
Status [?] Resolved Driver
Version 0.230 Fixed in Version 0.232 Build 64-bit
Fixed in Git Commit e825cb3 Github Pull Request #
Summary 07956: mslug, mslugx, garou: lower volume on parts of music
Description the music on any neogeo games have lower volume on some parts and some are higher
games i tested are mslugs series and garou mark of the wolves
maybe this have something to do with the recent updates on the sound ?

this is most notable on the train part of stage 8 music on metal slug x or 2

this videos are recorded from real hardware


and metal slug 1 on stage 2 music
Steps To Reproduce just play the game and hear the music
Additional Information
Github Commit
Flags Verified with Original
Regression Version
Affected Sets / Systems mslug, mslugx, garou
Attached Files
zip file icon stage (31,748 bytes) Apr 28, 2021, 05:43 Uploaded by Alex7
save sates
zip file icon stage (30,204 bytes) Apr 28, 2021, 05:48 Uploaded by Alex7
metal slug x
There are no relationship linked to this issue.
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Senior Tester
Apr 28, 2021, 08:56
is this report for 0.230 or 0.231?
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Apr 28, 2021, 10:02
Well I've used this nightly build so I guess it makes it 231 but that issues were found on 230 too
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Senior Tester
Apr 28, 2021, 10:33
Things may have changed. Try downloading the official 0.231 from and see if the issue still exists with that.
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Senior Tester
Apr 28, 2021, 18:55
edited on: Apr 28, 2021, 19:04
a nightly from 26th should be the freeze code however.

that said, the differences are not obvious, I can't hear them, and Youtube links of complete playthroughs aren't great - ideally the wavs need extracting from the video around the exact area the differences exist and wav files from MAME, recorded with -wavwrite, stripped down to the same segments for direct comparison.

these things are only obvious if you're already intimately familiar with the songs, we're not.

(also verification from multiple sources would help, just in case it's an issue with the capture hardware of this one specific uploader)
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Apr 28, 2021, 19:03
edited on: Apr 28, 2021, 20:00
I cannot spot (by ear) any difference on MS stage 2 either, comparing 0.231, 0.230 and the provided video, they all sound virtually identical.
Haven't checked the other sample (stage 8).

EDIT: you are right, hap, I can confirm I noticed the volume thing you describe on Garou MOTW selection screen. I will be back shortly to upload MOTW samples as well as re-check mslug (and provide cut/normalized recordings) to confirm also
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Apr 28, 2021, 19:40
edited on: Apr 28, 2021, 19:50
I think he means volume, and yeah I can clearly hear the difference. The lead instrument volume on mslug stage 2 is less audible on MAME 0.231.

*edit* if I can make a guess: the lead melody there is probably FM, and the bassline (and obviously the drums) sound like they're adpcm. FM volume may be too low in ym2610.
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Apr 28, 2021, 20:02
i think exactly what hap is saying
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Apr 28, 2021, 20:28
edited on: Apr 28, 2021, 20:33
We talked about this on Discord, I can confirm that there is something weird going on with the audio levels in Garou. It's very noticeable in the character select screen - there's supposed to be a trumpet playing in the background, and it is noticeably quieter in the current MAME release.

Edit: Also VERY noticeable in the ending theme for Hotaru Futaba.
(At 6:15) Playing track 0x072B in a music player (like the Universe Bios) will let you hear exactly what the issue is.
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Apr 28, 2021, 20:37
edited on: May 3, 2021, 14:45
I have uploaded mslug and garou recordings there: if that can help.
In the archive are included wavwrite for 0.229, 0.230, 0.231 as well as the audio for the reference videos I could find (the mslug stage 2 video mentionned in this bug report page, and for MOTW, recordings I found on Youtube - the filename is the video id: ttps://<filename> is the video link, the links are ttps:// and ttps:// I have removed the https to avoid automatic embed).
All samples cut and normalized (with Audacity, I didn't change DC offset) to make it easier to compare.
I can confirm I can hear the issue on mslug stage 2 as well (it is easier to spot at the very beginning of the stage music).

EDIT: edited DL link (sorry it was broken)
EDIT2: to Alex7, you have to remove the trailing comma from the hyperlink (it's not part of it), upon opening the page you have to accept their cookie policy and whatever before you can actually DL, it should work after that.
EDIT3: replaced wetransfer link with Mega link (because wetransfer link would expire quickly), also removed trailing comma to avoid hyperlink issues
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Apr 28, 2021, 21:05
it does not let me download could you upload to somewhere elese like google drive or mega?

also i was testing new MAME 231 issues are still present i tested the entire neo geo driver this time i can confirm driver is affected
some are very noticeable some are more difficult to spot
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Senior Tester
Apr 30, 2021, 06:59
Other good examples where to hear the differences are Blazing Star intro music and Pulstar intro music. I would say that all games in the driver are affected, so the title of the bug should be updated.
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May 1, 2021, 00:18
yeah i just said mslug mslug x and garou for refeference but all games on neogeo system are affected
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Senior Tester
May 3, 2021, 08:46
Looks like the portions of music with lower volume are played by the ADPCM-B channel, not the FM one. In particular, this line in DEVICES/SOUND/YM2610.CPP is the cause of the issue (line 287)
	m_adpcm_b.output(sums, 2, 0x01);
According to source code, that "2" value is used in a function to reduce/normalize the output volume. The value 2 is too much and causes the issues. To have things like they were before, simply change:
	m_adpcm_b.output(sums, 1, 0x01)
I wonder if the same fix should be done for YM2608.CPP since it's pretty identical... but for the moment nobody reported issue with this chip, only for YM2610.
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Steve Coomber
May 3, 2021, 10:04
There are not many games on MAME using the YM2608 which is probably why it hasn't been reported. I just tried out Mechanized Attack and noticed a difference in audio levels when comparing the latest MAME release to an earlier release (in my case MAME v0.223) so it could be affected by the same issue.
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Senior Tester
May 3, 2021, 12:27
I specifically adjusted mechatt based on the new code, so different levels are expected, however, if the levels change in the core again, they'll have be readjusted in the driver once more.
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May 8, 2021, 17:05
I've started to noticed that change of the instrument volumes with some Neo Geo games and then i realized that this got affected on any Neo Geo Game.
I am not sure if again, thanks to the YM chips change, other games that uses the YM sound chips also got the instrument volumes different.
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May 22, 2021, 18:17
Seems like boosting ADPCM-B by a factor of 2 for both YM2608 and YM2610 addresses this. I don't have any better data to go on, so I've applied the change.