Why is Skype sound quality sucking?

September 6, 2007 4:12 AM

Skype Sound Quality: Why does everyone think I'm in a horrible muffled echo chamber when I call them on Skype? Can I do something about this? Is there an alternative to Skype that would allow me decent quality calling to a land-line?

Configuration:
Mac OS X 10.4
1.25Ghz G4 Powerbook
768k up/4M down cablemodem connected to Airport Extreme Base Station


I edited shared.xml to turn OFF automatic gain control (My brother told me it sounded like my voice was amplitude compressed, such that when I didn't speak, he could hear all the background noise in the room, and when I did, the first syllable would cut out and then he could hear me as long as I didn't stop talking. Dont know if messing with shared.xml fixed that specific problem (haven't spoken to him on Skype since then).

Still, speaking with other people after messing with shared.xml hasn't significantly changed the call quality. People describe my voice as "echoey" and "muffled" and that its just very hard to understand. There is no delayed echo (people don't hear each word twice or anything). I dont have any problems hearing the person on the other end.

What's frustrating is that the sound quality is infinitely better with iChat (While sending a full video stream, no less) than with Skype, but I still need Skype to call land lines.

I'm fairly positive that this was going on when I was plugged directly into the Cable modem, so I dont think it's a problem with the Airport.

I'm using a Koss SD45 headset. It works great with iChat.

posted by sdis to computers & internet (15 answers total)

You could try using SIP instead, with a provider like PennyTel.
posted by flabdablet at 4:50 AM on September 6, 2007

Your configuration is a lot like mine. I found that I was having problems doing anything that was remotely processor memory intensive ranging from scrolling a long page to downloading something in the background. You mention your setup but are you sure that your available bandwidth is dedicated only to Skype [i.e. not background torrents/downloads/updates/wifi borrowers] and that you're not doing anything else on the machine while you're using it? Also make sure that it's the same when you're plugged in and not, just for troubleshooting purposes.
posted by jessamyn at 5:12 AM on September 6, 2007

i work for a distributed (san francisco, moscow, la plata, santiago, malta, london, etc) company and we have regular meetings by skype. people are on all kinds of machines (including macs, linux and windows - we develop software used on all platforms). skype normally works just fine. audio issues are usually due to people not using a decent microphones (a headest - headphone and mic - is ideal). sometimes network issues cause people to be disconnected. very occasionally (1 in 50 calls?) there is some weird issue with very bad sound quality that is fixed by reconnecting.

so i would check your mic and network connection.
posted by andrew cooke at 5:27 AM on September 6, 2007

are you sure it's not your airport? i do notice a difference between using a machine on wifi and one directly connected.

also, could you have the gain turned up too high on your mic? i don't know how you adjust that on a mac, but the symptoms your brother describes sound like the software is having to deal with a signal that is too loud.
posted by andrew cooke at 5:31 AM on September 6, 2007

Make sure you're using the latest version of Skype (even the 2.7 beta, which is stable for me). A colleague of mine went from a 2.0xxx version to 2.6 and sounds worlds better now.

I also agree that on your setup you need to make sure nothing else is happening: no downloads, no torrents, no backups, no indexing, no image processing, no virus scanning, no printer sharing, no active filesharing, no video playing, nothing. Make sure iTunes, RealPlayer, and Windows Media Player aren't running and muted, paused, or, for that matter, running at all. And make sure you don't have any web pages loaded that have embedded Flash that's constantly cycling.
posted by Mo Nickels at 5:35 AM on September 6, 2007

You will not get the same quality with SkypeOut as you will with computer-to-computer Skype or iChat.

When using SkypeOut, the program assumes that, since your voice will be mangled by the standard phone system anyway, it might as well throw away all that extra sound quality is capable of. I found that SkypeOut usually overcompresses a bit, and I end up with a sound quality that is a tad worse than normal phone-to-phone.

I don't know why it would sound muffled or echoey, though.
posted by gmarceau at 6:29 AM on September 6, 2007

gmarceau: Yeah, I noticed that I sound just fine when skyping echo123, so it's really an issue with SkypeOut specifically.

I'm pretty sure my mic isnt set too high, as my voice doesn't get louder than 80% of the bar in the sound control panel. I can try reducing it...

I'll also try shutting everything else off, but I wonder what the deal is with Skype to Skype working fine and SkypeOut not working well at all.
posted by sdis at 7:43 AM on September 6, 2007

You can try Gizmo to see if it does any better. Gizmo charges per-minute rather than Skype's flat fee, but, its rates seem pretty reasonable and I had okay luck with PSTN calls from it. There's also WengoPhone, which I haven't tried at all.
posted by boaz at 8:14 AM on September 6, 2007

You should really retest without the airport. Wifi adds many miliseconds to VOIP and drops packets like nobody's business. Best to rule this out right sooner than later.
posted by damn dirty ape at 8:58 AM on September 6, 2007

Does this also happen when you do a skype to skype call? The problem may be that the provider skypeout uses to connect you to the POTS system is crappy and is introducing all sorts of noise and echos. In other words this could be a telco problem not a computer problem.

Perhaps skypes tech support can answer this one.
posted by damn dirty ape at 9:04 AM on September 6, 2007

Well I've uncovered at least (a big) part of the problem. I haven't been using my headset microphone at all; my computer's been using its internal mic. Apparently the powerbook doesn't in fact have a microphone port; it has a line-in port, and it doesn't accept non-powered mics.

I've been using an iSight when I use iChat. Perhaps the microphone in the iSight is much better/more directional?
posted by sdis at 12:00 PM on September 6, 2007

I can't try it without the Airport, unfortunately. My ISP allows only one ethernet MAC address to use the cable modem, and I need to call in whenever I want to use a different network card. As such, I'm using my Airport's ethernet ID and that lets me use my two computers as I wish. Hurrah for crappy european ISPs!
posted by sdis at 12:13 PM on September 6, 2007

rats. i knew that and forgot to mention it. sorry.

i think the issue isn't just that the mic has to pick you up well, but that it needs to *not* pick up sounds from the speaker. so the isight is probably going to be better just because it's not so near where your speaker is (if you're using one).

can you use the isight's mic with skype? the gui does let you choose input devices on linux, at least (and that's the least well supported skype client).

this blog post may help - about 1/3 way down it explains how to get the isight mic working with other apps.
posted by andrew cooke at 2:44 PM on September 6, 2007

oh, and you can work round that stupid isp constraint by faking your ethernet mac address, but it seems to be non-trivial on osx (if you do this, don't use both machines together on the same network - instead it lets you replace one with the other). ah, on 10.4 is it easier.
posted by andrew cooke at 2:52 PM on September 6, 2007

My fiancee used skype to call me in Michigan from Toronto, and the quality of his calls improved drastically when he moved from a headset to a usb phone, like this one (which he actually has.) I hated that headset.
posted by santojulieta at 5:54 PM on September 6, 2007