Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
06805 Sound Minor Always 20 days ago 19 days ago
Tester wuemura View Status Public Platform MAME (Official Binary)
Assigned To Resolution Open OS Windows 10 (64-bit)
Status [?] Confirmed Driver midyunit.cpp
Version 0.192 Fixed in Version Build 64-bit
Summary 06805: narc, narc2, narc3: Annoying high pitch sound
Description Soon after the screen and sound test a high 15 Khz ~ 16 Khz pitch, very sharp beep start to play throughout the game. It looks like one of the channels are out of phase, if you move you head this sharp beep start and stops.
The beep vanishes after you quit the emulation.
Steps To Reproduce
Additional Information
Flags
Regression Version
Affected Sets / Systems narc, narc2, narc3
Attached Files
png file icon 20171226_myProject_214341.png (143,616 bytes) 20 days ago Uploaded by wuemura
wuemura
png file icon harmonics.png (21,855 bytes) 19 days ago Uploaded by wuemura
wuemura
png file icon harmonics2.png (178,823 bytes) 19 days ago Uploaded by wuemura
wuemura
zip file icon AUDIO.zip (75,870 bytes) 19 days ago Uploaded by wuemura
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There are no relationsihp linked to this issue.
Notes
7
User avatar
No.14570
vidpro1
Developer
20 days ago
edited on: 19 days ago
If I do recall I believe this is the CVSD channel doing this. Harris 55536.
Update: If you crank up the CVSD volume the noise is there you might need to turn up all the DACS and Yamaha as well.

User avatar
No.14574
Tafoid
Administrator
20 days ago
I don't hear it in 0.192 or current GIT.
It could be my cheap headphones and speakers lack the range or I'm just not able to detect that high of a range. Have you experienced versions of MAME where this didn't happen?
User avatar
No.14576
wuemura
Tester
20 days ago
I've tested with 0.192 and mame0192-771-ge473764e04-dirty, happens on both.
Version 0.140 doesn't have this issue, I could pin point to version 0.145 but it could be earlier since I can't download other versions right now.
That tone is very sharp and loud, tested with a Sony KDL-47W802A that I use as a monitor, Sennheiser HD 800S headphone and a Onkyo HT-S5600.
User avatar
No.14582
Haze
Senior Tester
19 days ago
edited on: 19 days ago
It's entirely possible the real game does this, and the speakers the cab shipped with weren't good enough to reproduce it.

even with a decent speaker setup here, I can't hear it tho.

there is a very visible DC offset if I look at the output of -wavwrite before coining up however

User avatar
No.14583
vidpro1
Developer
19 days ago
edited on: 19 days ago
I think quite a number of the games in MAME that use a lot of channels and chips have this problem like Exidy Mouse Trap.
I have narrowed it down to the CVSD. If you turn down the volume versus other chips it goes away.

User avatar
No.14584
wuemura
Tester
19 days ago
edited on: 19 days ago
Looks like a bunch of odd harmonics.

About the DC Offset, are 9369 on both sides.
 Analyzing...

    Gain   |  Peak  | Scale | New Peak |Left DC|Right DC| Track
           |        |       |          |Offset | Offset |
 --------------------------------------------------------------
  +5.26 dB |  16384 |  1.83 |    30020 | 9369  |  9369  | AUDIO.wav

User avatar
No.14585
vidpro1
Developer
19 days ago
edited on: 19 days ago
Most games I have seen with the CVSD have the hissing problem if there are more than three sound devices.

Exidy Mouse Trap
PC Speaker chip but has three channels at one plus noise generator and CVSD chip.

Narc's sound board has the following
 * music: 6809 driving YM2151, DAC
 * effects: 6809 driving CVSD, DAC

The other Williams Games only have (Trog, Smash TV etc) - No audio hiss
 * music&effects : 6809 driving YM2151, DAC, CVSD