Re: kern/51784: "Synthesized" speaker hums

[Nathanial Sloss <nat%netbsd.org@localhost>]

The following reply was made to PR kern/51784; it has been noted by GNATS.

From: Nathanial Sloss <nat%netbsd.org@localhost>
To: gnats-bugs%netbsd.org@localhost
Cc: gnats-admin%netbsd.org@localhost,
 netbsd-bugs%netbsd.org@localhost,
 paul%whooppee.com@localhost
Subject: Re: kern/51784: "Synthesized" speaker hums
Date: Wed, 24 May 2017 10:13:21 +1000

 Hi,
 
 I've just finished a better implemetation of audiobell that should have little 
 to no hum.  The probelm with the existing audiobell.c is that the maximum bell 
 pitch is just 4 kHz with the patch it would be 22 kHz.
 
 The resolution of the data used to generate the sine wave has been increased 
 from 65 bytes to 2049 bytes, as the original 65 byte version genetated a 
 rather square-ish sinewave at some frequencies and the hum would be a 
 harminic.
 
 The hires version generates a better looking sine wave.
 
 To use apply this patch:
 ftp.netbsd.org/pub/NetBSD/misc/nat/hiresbell.diff
 and add the following to your kernel config:
 options HIRES_BELL
 
 Please let me know if this resolves the "hum".
 
 Best regards,
 
 Nat
 
 
 On Mon, 22 May 2017 21:10:00 Paul Goyette wrote:
 > The following reply was made to PR kern/51784; it has been noted by GNATS.
 > 
 > From: Paul Goyette <paul%whooppee.com@localhost>
 > To: gnats-bugs%NetBSD.org@localhost
 > Cc:
 > Subject: Re: kern/51784: "Synthesized" speaker hums
 > Date: Mon, 22 May 2017 19:05:36 +0800 (+08)
 > 
 >  FWIW, this is still an issue with 7.99.72