AAC vs SPX
Um comparativo detalhado de AAC Audio e Speex Audio — tamanho de arquivo, qualidade, compatibilidade e qual escolher de acordo com seu fluxo de trabalho.
AAC Audio
Audio FilesAAC is a lossy audio codec that delivers better sound quality than MP3 at similar bitrates. It is the default audio format for Apple Music, YouTube, and most streaming services.
Sobre os arquivos AACSpeex Audio
Audio FilesSpeex is an open-source audio compression format specifically designed for speech encoding. It uses Code-Excited Linear Prediction (CELP) and supports narrowband, wideband, and ultra-wideband modes for different speech quality requirements.
Sobre os arquivos SPXComparativo de vantagens
AAC Vantagens
- Better quality than MP3 at equal bitrate — the industry standard since 2000s.
- Universally supported on every smartphone, OS, and browser.
- Efficient on battery thanks to widespread hardware decoding.
- Scales from 8 kbps speech (HE-AACv2) to lossy-transparent 320 kbps.
- Five-channel + LFE surround support out of the box.
SPX Vantagens
- Patent-free voice codec.
- Three sample-rate modes for voice.
- Low CPU decode.
Limitações
AAC Limitações
- Patent-encumbered — encoders have licensing fees, which is why open alternatives (Opus, Vorbis) exist.
- Slightly more complex to encode than MP3.
- Raw .aac streams carry no seek index — tooling often prefers M4A/MP4 containers.
- Lossy — not suitable for archival or studio production.
SPX Limitações
- Deprecated in favor of Opus.
- No music support.
- Rarely used in new projects.
Especificações técnicas
| Especificação | AAC | SPX |
|---|---|---|
| MIME type | audio/aac | audio/speex |
| Extensions | .aac, .m4a, .mp4 (container-dependent) | — |
| Standard | ISO/IEC 14496-3 | — |
| Variants | AAC-LC, HE-AAC, HE-AACv2, AAC-LD, xHE-AAC | — |
| Sample rates | 8-96 kHz | — |
| Extension | — | .spx |
| Container | — | Ogg |
| Modes | — | Narrowband/Wideband/Ultra-wideband |
| Successor | — | Opus |
Tamanhos típicos de arquivo
AAC
- Speech podcast (64 kbps) 1 MB/min
- 3-min music track (128 kbps) 3 MB
- 3-min music track (256 kbps) 6 MB
- Broadcast-quality 5.1 (384 kbps) 9 MB for 3 min
SPX
- 1 min voice (wideband 24 kbps) ~180 KB
Pronto para converter?
Converta entre AAC e SPX online, grátis e sem instalar nada. Upload criptografado, exclusão automática em 60 minutos.
Áudio Hi-Res 24-bit ou discografias completas em lote?
Para converter coleções de música sem perdas (FLAC/ALAC) preservando 192 kHz sem depender de upload na internet, recomendamos suítes de áudio locais.
Pagamento único sem renovação para converter arquivos de até 1 GB e lotes de 50 por 24 horas.
Converta vídeos, PDFs e áudios pesados direto no navegador sem anúncios e com fila prioritária.
Processamento em nuvem de alta velocidade para arquivos de até 1.024 MB, retenção de 24h e suporte prioritário.
Conversão em lote sem perdas mantendo metadados ID3v2 e capas de álbuns.
Processamento multi-core de discografias inteiras com verificação CRC bit-perfect.
Perguntas frequentes
AAC (Advanced Audio Coding) is a com perdas audio formato padrãoized by ISO como o successor to MP3. It delivers better sound quality than MP3 at equivalent bitrates e is the default audio formato para Apple products, YouTube, e most streaming services.
SPX (Speex Audio) is an audio formatoo de arquivo used to store sound recordings — music, voice, podcasts, sound effects. The formato defines how the audio samples are comprimido (or stored raw), what bitrates are suportado, e how metadata como title, artist, album, e cover art is embedded. It is part of the audio arquivos family.
AAC arquivos reproduzir in iTunes, Apple Music, VLC, Windows Media Player, e all moderno web browsers. AAC is natively suportado no iOS, Android, macOS, e Windows.
VLC, foobar2000, e the default media players no Windows e macOS handle SPX natively. On mobile, iOS Music e Android media apps vary in their support — popular formatoos funcionar everywhere; niche ones may need a dedicated app. If playback fails em um device, convertendo to MP3 ou AAC Geralmente solves it.
AAC is technically superior, offering better quality at the same bitrate. usar AAC para Apple ecosystem e dispositivos modernoos. usar MP3 only when you need compatibilidade com very old hardware like legacy car stereos ou basic MP3 players.
Upload the SPX to KaijuConverter e pick MP3, WAV, FLAC, AAC, OGG, ou any other target. Our FFmpeg pipeline decodes the audio e re-encodes para o target formato at sensible default bitrates (VBR ~190 kbps para music, 96 kbps para speech). Metadata e cover art travel com the audio where both formatoos support them.