Dial Up Modem Sounds, 56K Edition

The sound of 56K for various modem models and standards. Prior to V.90 there were competing x2 and K56 Flex standards, which are included here. Even when V.90 was official though, different models of modems tended to sound different from one another when connecting. This is the result of part of the V.90 spec called the Digital Impairment Learning sequence (DIL). The analog (client) modem asks the digital (ISP) modem to send a set of symbols (sounds). When the analog modem receives those symbols, it can compare the sound it asked for and the sound it received to determine how it was degraded by how the digital signal was handled along the path from the ISP, and then adjust the connection speed to compensate. The digital signal might be affected by things like Robbed Bit Signalling and digital pads.

The interesting thing is that the V.90 spec doesn't actually specify what the DIL sounds should be, just that the digital modem should send whatever the analog modem asks for. The result is that it can sound quite different for different client modems. This video is just a sample of a few different modem models connecting using V.90.

Server Specs:
- AMD K6-2 @ 350MHz
- 512MB SDRAM
- 16GB SD Card w/ SD/IDE Adapter
- 10Mbps 3COM 3C509 ISA Ethernet Adapter
- US Robotics Courier I-Modem (x2 and V.90 support)
- Patton Dialfire 2977/B4/U (K56 Flex and V.90 support)
- Dialogic Diva 4BRI-8M PCI v2 (V.90 support)
- Windows Server 2003R2

Laptop #1 Specs:
- Toshiba Tecra 500CDT
- Intel Pentium @ 120MHz
- 144MB EDO RAM
- 1.2GB IDE HDD
- 12.1" 800x600 Active Matrix TFT LCD
- Windows 98SE

Laptop #2 Specs:
- Compaq Armada M300
- Intel Pentium II @ 333MHz
- 128MB SDRAM
- 6GB IDE HDD
- 11.3" 800x600 Active Matrix TFT LCD
- Windows 2000 Professional

Laptop #3 Specs:
- Lenovo Thinkpad X1 Carbon G9
- Intel Core i7-1185G7
- 32GB LPDDR4-4266
- 1TB Western Digital SN850 SSD
- 14" 1920x1200 IPS LCD
- Windows 2000 Professional (in a VirtualBox VM)

Teltone ILS-2000 ISDN Simulator
Dialogic DIVA T/A ISDN terminal (used for Analog/Digital connection)

0:00 Intro
0:04 x2
0:30 K56 Flex
1:05 US Robotics V.90
1:36 Zoom V.90
2:11 Hayes V.90
2:40 Intel V.90
3:11 Creative Labs V.90
3:45 Xircom V.90
4:25 Lucent Softmodem V.90
4:59 Agere USB Softmodem V.90
5:37 Frank the Snake

[izaixspace]

I find these so mesmerizing, I never used a modem in its days and I can only imagine how exiting (or slow) must've been to connect to the internet back when it was still a novelty :D

[FoxRain]

Bro the wait just to play flash games. Watching videos over and over while it buffered the next frame. Those were the good old days.

[homg]

This transported me right back to 2002! Our cousins had internet in the 90s, so we were late to the game, but hearing this sound for the first time, in our own home, brought me immense joy!

[jorgon]

Hearing that K56 flex tone brought me straight back to being a kid, waiting 25 minutes for a game to load on the cartoon network site only for someone to ring the home phone and mess it all up, damn, got me feeling old af

Weird I had no idea at the time what type of modem or internet connection we even had yet I recognise it instantly

[Slurkz]

Thanks for documenting this fascinating but thankfully vansished part of history. 💜
Listening to this captures the anticipation of connecting to the adventurous world I perceived the www to be at the time.

[CaptCovfefe]

5:26 if you could turn the feeling of hitting your funnybone into a sound

[phlydude]

those V.90 sounds sure do bring back memories followed by "Welcome....You've Got Mail" - funny how when you were trying to get the 53.3 connection to work, if one of the numbers you dialed sounded funny or gave one of the error correction tones, you'd kill it and grab a new line and try a new number. We knew that error was unstable and we would likely get kicked off while trying to find someone new to meet in the local chat room after asking A/S/L. 🤣

[sonicunleashedfan]

For the Intel modem, I was half expecting the V.90 DIL portion to use the Intel jingle (or at least a portion of it). Good video

[hunterduker]

TNX for this video! More than 23 years last time i listened the X2 handshake 🙂

[lucsirotouka]

Thank you for sharing these sounds, this brings back the pre-broadband experiences.
From memory when my home modem could dial a 56K speed, the handshake sound is most like the Hayes V.90 one in this video. The sound from 2:35 to 2:37 sounds like it's struggling lol.

[metro]

A fellow DankPods viewer, I see.
But really tho, this video is really interesting. I enjoyed it!

[FriendlyMexican]

2:34

My neurons processing my moves in the morning.

[KatTheFoxtaur]

Definitely the sound I remember best was the Hayes V.90. Basically every 56k modem I used back in the day had that same kind of handshake sound. I don't recall much of what the sound was like from my 14.4k or 33.6k modems, but I know that I had 56k for the longest amount of the time that we had dial-up internet, which we first got in 1994. I do recall that the length/delay/timing of some of the test tones were a bit different, but they were the same tones.

[randomexcessmemories]

Fascinating! I'd love to have a setup like this to mess around with.
And is that Frank the Snake from Dankpods?

[XENON]

wait thats frank from dankpods?? dude best channel ever!

[JMein]

I must've lived in too rural of an area.
Because I remember the second half of the connection noises repeating to confirm stability.

[kelvinstokes]

Oh wow, an Armada M300! I had one of those for a few years - seriously nice computer, for its time!

[jaedenspider]

Back in the day my dad used to have like a box full of DSL filters cuz that's how bad the DSL problem was

[tubeDude]

Should have added a *Racal-Vadic* modem as well. I worked for them in Silicon Valley '85 to '89

[vsharun]

Fantastic job mate. Exactly year ago I focused on the same idea, but all-cisco backhaul: C2811 w VIC3-2FXS replaced then with VIC3-4FXS (VIC2/VIC1-FXS cards has inferior DAC quality and 44k limited) + E1/T1 WVIC and AS5300 w/MICA modems as a V.90/V.92 digital modem provider. Got fairly stable 54666/31200 V.90/V.92, no digital uplink V.92 support unfortunately with MICA modem at all. USRobotics Courier and Sportsters are the top performers, with ZyXell NEO next.