Late 2013 MacBook Pro review: audio

▼ No more bottlenecks: the late 2013 MacBook Pro reviewed

Over the next few days, I'll publish my review of the new 13" MacBook Pro here in several installments. This is the fourth one, looking at the MacBook Pro's audio capabilities. Also see the earlier instalments about battery life, CPU performance and ports and networking

Don't worry, I'll be discussing the high-resolution screen soon enough. But first let's listen to the audio. The late 2013 13" MacBook Pro has three slits along both sides, starting at the front and reaching about two thirds towards the back. The slits are somewhat hidden where the side and bottom meet. I assume they're mostly there to suck in air, that is then directed out the back under the hinge. But they also let most of the sound out from the two speakers that sit right along those slits. The built-in speakers provide clear, bright audio with a modest, but workable amount of bass—more than what the MacBook Air can muster. The maximum volume is also a few ticks higher. It's certainly good enough for some casual listening at your desk.

When the optical drive was excised from the MacBook Pro line, it took the audio line in port with it. Arguably, this was a fairly useless port anyway, as you couldn't use it to connect a microphone. The headphone port on the other hand, does support microphones though the a fourth signal line, just like the iPhone. But it has another trick up its sleeve: optical audio out. With a special plug that connects to a TOSlink cable you can transmit digital sound to an amplifier with a digital input. This is how we played back DVDs with surround sound back in the day—the DVD Player application can send the digitally encoded 5.1 surround signal over the optical cable, and the receiver decodes it.

However, these days the sound is typically transmitted alongside video through an HDMI cable. The new MacBook Pro has an HDMI port and can also connect to HDMI with the right cable over its Thunderbolt/miniDisplayPort ports. You can change audio settings, including audio output over HDMI, in the Audio MIDI Setup program.

Like an optical TOSlink connection, HDMI can carry compressed/encoded digital surround sound. But unlike an optical TOSlink connection, HDMI can also carry 5.1 or even 7.1 channel uncompressed, decoded audio. If you have a receiver/amplifier or TV that can accept this many channels. You'll encounter video with 5.1 (rarely 7.1) surround sound in two main flavors: Dolby Digital AC3 and MPEG4 AAC. There's also DTS and a few higher end Dolby/DTS variants. It's also possible for video files to have multiple audio tracks. For instance, many TV shows from the iTunes store have an AC3 surround track and a AAC stereo track.

For playing back videos with AC3 and DTS surround audio tracks, your best bet is to use VLC and tell it to use HDMI (encoded output) as the audio device. This way, the audio data is sent to the surround receiver as-is, and all the channels will go to the right speakers. When I let VLC decode the audio itself and just use "HDMI" as the audio device, the audio gets sent to the wrong speakers.

Alternatively, use an Apple TV to play them. This also works for videos from the iTunes Store, which VLC can't play because they're protected. You can of course play those in iTunes, but then you once again get audio sent to the wrong speakers or you only get stereo audio.

Interestingly, iTunes can decode videos with 5.1 surround sound in AAC format, and both iTunes and VLC send the channels to the right speakers. But for AAC you can't use encoded audio output, even though I'm pretty sure modern surround receivers have no problem decoding it. The Apple TV, on the other hand, will decode AAC surround sound, but then send the result to a receiver or TV as stereo, defeating the purpose of having 5.1 audio.

• Battery life
• CPU performance
• Ports and networking
• Audio
• General impression and the screen(s)

Permalink - posted 2013-11-08

Some of my favorite podcasts

▼ Anyone who's been reading my stuff on Ars Technica will know that I love podcasts. I'm always adding new ones to my rotation and retiring ones that have run their course for one reason or another. So I thought I'd share some of my current favorites with you.

Two fairly new podcasts that I like a lot are Just The Tip and Clockwise. Just The Tip (RSS, iTunes): "Internet rapscallions Amy Jane Gruber and Paul Kafasis try to make you laugh, in thirty minutes or less." It defies description, but somehow it works. Bonus: unlike most other weekly podcasts, it usually drops early in the week.

Clockwise (RSS, iTunes) comes from TechHive, the home of Macworld and PCWorld. Don't let the gimmicky format used in the first episode deter you, it quickly fades into the background, but it does allow them to get through a whole bunch of topics with a relatively large group of participants in about thirty minutes. A breath of fresh air compared to uninspired episodes of the Accidental Tech Podcast (RSS, iTunes) or The Talk Show (RSS, iTunes)—although I keep listening to those just in case there's an inspired episode, in which case their excessive length is a boon.

The Nature Podcast (RSS, iTunes) and Freakonomics Radio (RSS, iTunes) are a bit overproduced (I really hate that "coming up..." stuff! Come on people, I'm already listening), but not to be missed.

Philosophy Bites is not for everyone, but if you're interested in philosophy, there's a lot of good (bite-sized) stuff there. Be sure to check out the website, because the RSS feed doesn't have the back episodes.

For some strange reason I don't listen to any Dutch language podcasts except public radio programs. If anyone has any tips for Dutch (or English!) podcasts, send me an email or Twitter me.

Permalink - posted 2013-09-13

The mute switch issue

▼

The past week there's been a lot of blog talk about an iPhone going off during a performance of the New York Philharmonic. Apparently someone had just had his Blackberry replaced with an iPhone, and when the iPhone alarm went off despite the "ringer/silent" switch set to silent, the poor new iPhone user first of all didn't notice it was his phone interrupting the performance at first, and then had a hard time killing the alarm.

Cue a series of blog posts arguing for and against the situation where alarms go off even if the ringer/silent switch is set to silent. Andy Ihnatko is strongly against with John Gruber, and Marco Arment to a slightly lesser degree, in favor.

With the ringer/silent switch (let's just call it the mute switch) set to silent, the iPhone will play audio and video with sound, and third party developers are also allowed to play sounds if this is the direct result of the user's intent. All other sounds, with one exception, are silenced. That exception is alarms and timers set through the clock utility. (Alarms set in the calendar application are silenced.)

The reason for this is obvious to anyone who uses the mute switch in practice: it's way too easy to forget to turn the ringer back on. Oversleeping because your alarm didn't go off as a result would be a very bad thing. And this brings us to the reason why what happened at the New York Philharmonic is so unusual: as a rule, people don't set alarms to go off in the middle of a performance they plan to attend. So having alarms sound even if the phone is set to be silent shouldn't lead to trouble in most cases.

Some people want Apple to add settings to customize this behavior. As a rule, Apple doesn't like to add settings, although you wouldn't know it from the iPhone settings tool. Looking at the notification settings, which are quite unwieldy, it's obvious to me that having something like that for the mute switch behavior for different kinds of sounds wouldn't be very useful. Even for people who are prepared to go in and change the defaults, it's just too much work to get everything configured just right. Especially when the consequences of mistakes can be significant.

But I have a different suggestion. When the user sets the switch to "silent", a requester should be shown that says "an alarm will sound at 7:00" (if you've set your alarm to go off at 7, of course). With that, the ringer volume should be shown. This allows users to turn down the ringer volume to zero. (Unfortunately, as things are now, it's not possible to turn the ringer volume down all the way to silent, although at the minimum volume it's not going to interrupt a live performance.)

I think this will give users the info they need to correct possible mistakes without making life for average users more complex. On his podcast, John Gruber argued against a solution like this because users may turn the switch without looking. It's true that this not a 100% solution, mistakes are still possible. But if users know that when flipping the mute switch a warning about alarms will show it's easy enough to glance at the screen if they're even a little bit concerned about alarms. And after doing this the first few times while looking, they know that alarms will sound even when the switch is set to "silent".

That said, I wouldn't mind having a feature on my iPhone that I had years ago on my Nokia phone, where you could set a profile (sounds yes/no, vibration yes/no) and have it switch back to the default profile at a a given time. Really useful if you're going to the movies or some such and need the phone to be quiet for some fixed amount of time.

Permalink - posted 2012-01-19

Looking forward to 3G/UMTS: better sound!

▼ A long, long time ago, someone decided that an 8 kHz sampling rate was good enough for phone conversations. That's pretty crappy. And cell phones use last century's compression to make it sound even worse. But there is light at the end of the tunnel: AMR-WB on UMTS!

Around 1998/1999 cell phones were cool. At least, to me: I just got my first one, and three new cell networks were being built in the Netherlands. On February 4, 1999, the strangely named mobile operator 'Ben' started, and I signed up with them that day.

In the intervening years I stopped following cellular technology and I only got a new phone in 2004 (or was it 2005?) because I got fed up with the inability to sync contacts between my Mac and my old phone.

But after all the rumors about 3G iPhones I started reading up on 3G (UMTS) a bit, and it turns out that 3G has something really good in store: the AMR-WB codec. Originally, GSM used a pretty pathetic full rate codec, but even its enhanced replacement sounds significantly worse than uncompressed audio. And there's still the issue that all frequencies below 300 and above 3400 Hz are thrown out.

With AMR wide band, the frequency range is from 50 to 7000 Hz, which is a lot better: listen to the samples on this page.

AMR-WB uses only 12 - 13 kbps like HR and EFR, so there's really no reason for UMTS networks not to use it. However, because the higher quality audio obviously doesn't survive conversion to/from standard 8 kHz encoding, you'll only hear the higher quality on calls between AMR-WB capable phones on networks with AMR-WB capable interconnects. So it's going to take a while before the majority of calls will sound better.

But it's a start and I'm now actually looking forward to having a 3G phone. Preferably an iPhone.

Permalink - posted 2008-05-04