Editing Sound card (section)

===Feature evolution===
{{Unreferenced section|date=May 2024}}
Early [[ISA bus]] sound cards were [[half-duplex]], meaning they couldn't record and play digitized sound simultaneously. Later, ISA cards like the SoundBlaster AWE series and Plug-and-play Soundblaster clones supported simultaneous recording and playback, but at the expense of using up two IRQ and DMA channels instead of one. [[Conventional PCI]] bus cards generally do not have these limitations and are mostly full-duplex.

Sound cards have evolved in terms of digital audio sampling rate (starting from 8-bit {{nowrap|11025 Hz}}, to 32-bit, {{nowrap|192 kHz}} that the latest solutions support). Along the way, some cards started offering [[wavetable synthesis]], which provides superior [[MIDI]] synthesis quality relative to the earlier [[Yamaha OPL]] based solutions, which uses [[Frequency modulation synthesis|FM-synthesis]]. Some higher-end cards (such as [[Sound Blaster AWE32]], [[Sound Blaster AWE64]] and [[Sound Blaster Live!]]) introduced their own RAM and processor for user-definable sound samples and MIDI instruments as well as to offload audio processing from the CPU. Later, the integrated audio ([[AC'97]] and later [[Intel HD Audio|HD Audio]]) prefer the use of a software MIDI synthesizer, for example, [[Microsoft GS Wavetable SW Synth]] in [[Microsoft Windows]].

With some exceptions,{{efn|The [[E-MU]] card family, the Gravis GF-1 and AMD Interwave support up to 32 channels.}} for years, sound cards, most notably the [[Sound Blaster]] series and their compatibles, had only one or two channels of digital sound. Early games and [[MOD (file format)|MOD]]-players needing more channels than a card could support had to resort to mixing multiple channels in software. Even today, the tendency is still to mix multiple sound streams in software, except in products specifically intended for gamers or professional musicians.

====Crippling of features====
{{Main|Crippleware}}
As of 2024, sound cards are not commonly programmed with the audio loopback systems commonly called ''stereo mix'', ''wave out mix'', ''mono mix'' or ''what u hear'', which previously allowed users to digitally record output otherwise only accessible to speakers.

[[Lenovo]] and other manufacturers fail to implement the feature in hardware, while other manufacturers disable the [[device driver|driver]] from supporting it. In some cases, loopback can be reinstated with driver updates.<ref>Installing an LG driver on many Dells with Sigmatel 92xx chip, including the Inspiron 6400 and other models can add support for stereo mix. [http://en.community.dell.com/support-forums/laptop/f/3517/p/18549377/18672363.aspx#18672363] {{Webarchive|url=https://web.archive.org/web/20130520132558/http://en.community.dell.com/support-forums/laptop/f/3517/p/18549377/18672363.aspx#18672363|date=2013-05-20}} Reference dates from 2007 and covers Windows XP and Vista.</ref> Alternatively, software such as [[Virtual Audio Cable|virtual audio cable]] applications can be purchased to enable the functionality. According to Microsoft, the functionality was hidden by default in Windows Vista to reduce user confusion, but is still available, as long as the underlying sound card drivers and hardware support it.<ref>{{cite web|url=https://blogs.msdn.microsoft.com/larryosterman/2008/07/11/whatever-happened-to-wave-out-mix/|title=Whatever happened to Wave Out Mix? – Larry Osterman's WebLog – Site Home – MSDN Blogs|website=Blogs.msdn.com|access-date=September 7, 2017}}</ref> 

Ultimately, the user can use the [[analog loophole]] and connect the line out directly to the line in on the sound card. However, in laptops, manufacturers have gradually moved from providing 3 separate jacks with TRS connectors{{snd}}usually for line in, line out/headphone out and microphone{{snd}}into just a single combo jack with TRRS connector that combines inputs and outputs.