Viewing Issue Advanced Details
ID Category [?] Severity [?] Reproducibility Date Submitted Last Update
03297 Sound Minor Always Jul 5, 2009, 20:30 Dec 18, 2020, 07:54
Tester Yonah View Status Public Platform MAME (Official Binary)
Assigned To Resolution Bugs That Aren't Bugs OS
Status [?] Resolved Driver midyunit.cpp
Version 0.132 Fixed in Version Build
Fixed in Git Commit Github Pull Request #
Summary 03297: smashtv: Music sputters/lags when doors open
Description From the start of game play in the first room, the background music seems to lag or sputter while playing the game. This seems to happen when a door opens either to bring in more enemies or while the player is moving to the next room.

When the sound CPU is over-clocked to 150% these sound problems are alleviated. Most interestingly, if the CPU is under-clocked by even as little as 95% these problems become severe very quickly.
Steps To Reproduce 1) Start the emulation
2) Go to "Slider Controls"
3) Lower the volume of the DAC and CVSD volume to 0.00
4) Play the game, listen for tempo interruptions, particularly with bass notes.
5) Reset the game (shift + F3)
6) Adjust CVSDCPU to 150%
7) Play the game, notice the lack of sound problems.
8) Reset the game (shift + F3)
8) Adjust CVSDCPU to 90% or below.
9) Notice how sound problems become worse.
Additional Information I have included 2 files, both with DAC and CVSD muted, one at normal CPU speed, the other Adjusted to 150% above normal.

Over the weekend I located a SmashTV machine of unknown version at a local establishment. If necessary I could try to get a sound recording of the game if no one else has access to the real hardware, though I lack the proper equipment to do this and the noise levels in the surrounding are excessive.
Github Commit
Regression Version
Affected Sets / Systems smashtv
Attached Files
mp3 file icon Normal.mp3 (1,406,825 bytes) Jul 5, 2009, 20:30
mp3 file icon Adjusted.mp3 (1,407,589 bytes) Jul 5, 2009, 20:31
There are no relationship linked to this issue.
User avatar
Jul 6, 2009, 11:02
If there is indeed a problem, I'm fairly sure that the cpu speeds are not the fault. Midway Y Unit is well documented. Pending some actual PCB investigation and recordings, I would mark as possible. Since it's not possible to mute channels in the arcade game - this might have never been noticed as original behavior. I'll wait for the authority to chime in on this, however.
User avatar
Senior Tester
Dec 18, 2020, 07:36
edited on: Dec 18, 2020, 07:45
The sound bug is present in the original hardware too. It is perfectly noticeable while crossing the door in level transitions as I'm showing in the video below. Due to the gameplay sounds effects, it is harder to check when doors open for enemies to come into the arena, but it is also noticeable anyway: