Nearly all Macs have built-in speakers but, while Apple is working to improve its sound quality, on most Macs the speakers simply don’t get loud enough. They’re generally fine for close listening in a quiet environment but once you add some ambient noise or move away from the computer, Mac users often find themselves wanting more volume than the OS X volume control will give them.
Boom offers two basic functions: 1) a system-wide volume booster and equalizer that can increase your Mac’s system volume by up to 400 percent, and 2) a converter that increases the volume of audio and video files.
Installing Boom is simple: it is available on the Mac App Store and can be downloaded and installed with one click. Before it can really get to work, however, Boom will ask you to install an “audio component” upon running the application for the first time.
This small, 300 KB component is what gives Boom control over your Mac’s system volume. Once the audio component is installed, you’ll have access to Boom’s system-wide volume booster and equalizer.
System Volume Boost
Those looking for a simple system volume boost can adjust the slider for “Boom volume” inside the app itself, or use the handy menu bar icon. Hotkeys can also be enabled to control the Boom volume from your keyboard. By default, Command-Shift-(plus) and Command-Shift-(minus) raise and lower the volume, respectively.
Once activated, Boom’s proprietary audio algorithms kick in and do their best to increase the audio volume without adding distortion. The idea works great in practice, at least to a point. Setting Boom’s volume too high will result in distortion and clipping, but if you need to play audio from your Mac that loud, you should really invest in a set of external speakers.
The advantage of Boom is that the volume boost is system-wide, meaning that any activity on your Mac — such as games, iTunes music, online web video, or audio chatting — can have its volume increased. Also, while most users with external speakers don’t need the kind of volume increase that users with built-in speakers do, Boom can still amplify the volume of those external speakers if desired.
The volume increase is truly impressive. Both our 2011 MacBook Air and 2011 iMac reached volume levels we had never experienced before. Not to say that such high volume is always a good thing — as we mentioned above, there was definitely audio distortion at the high end of the Boom slider — but a value of between 20 and 50 percent on the Boom slider resulted in a noticeable volume increase with no discernible distortion or clipping.
Users looking for extra audio processing can activate and adjust the built-in equalizer. In testing, we found that the Music preset resulted in a very nice sound while listening to songs with iTunes. Note, however, that we turned all of iTunes’s own music equalization off. When both the iTunes and Boom equalizers were enabled, the audio became too processed and simply didn’t sound good.
We also didn’t find the other presets very useful. Both movies and vocal audio tracks sounded better with the Music preset than with their identically named presets and the remaining options either muddied or clipped the audio. Prior to Boom we used the iTunes Rock equalizer preset. Going forward, we’ll stick with Boom’s Music preset, which not only sounds better but will give us system-wide equalization rather than just within iTunes.
File Audio Boost
Another nice benefit of Boom is the ability to boost the volume of individual audio and video files. Simply launch the app, switch to the Boost File section, and drag and drop files into the conversion queue. Once your files are in the queue, set the desired audio increase by adjusting the slider and press Boost. Boom will create a copy of each file with a “_boosted” suffix and increase the audio volume in those files by the designated amount.
File types supported by this feature include mp3, m4a, aiff, caf, and wav for audio and mov, mp4, m4v, avi, 3gp, 3g2, mpg, and dv for video. However, like many applications that open and modify media files, Boom cannot accept files protected by DRM. Those files that can be converted can either be saved to a set location on the user’s drive or automatically added to iTunes.
In our testing, the conversion was remarkably fast. A four minute m4a file converted in about 3 seconds and a 3 minute 720p mp4 video file converted in about 8 seconds on a 2011 3.4 GHz i7 iMac (Note that the files were located on the iMac’s internal SSD; users with traditional hard drives may experience slightly longer conversion times).
Our audio track’s waveform before the “Boom Boost”
An analysis of the pre- and post-Boom waveform of a converted file shows that the app merely increases the volume of the audio track. This is something that users can do for free with third party open source tools but if you have many files to process, Boom can save a significant amount of time.
Our audio track’s waveform after the “Boom Boost”
System Resource Usage
We’re always wary of system utilities that run in the background on our Macs. Many provide valuable functionality but, often, the hit on system performance is too large to justify.
Thankfully, Boom is fairly light on resources. On our 2011 13-inch MacBook Air at 1.7 GHz with 4 GB of RAM, Boom at idle hovered between 1 and 2 percent of CPU usage. While boosting live audio volume, it averaged around 5 percent, and peaked around 10 percent when changing volume levels with the keyboard hotkeys. On our 2011 27-inch iMac at 3.4 GHz with 32 GB of RAM, Boom never topped three percent of CPU usage under any circumstance. On both machines, it used between 30 and 40 MB of RAM.
For users who do processor-intensive editing or rendering on their Macs and can’t afford to spare a single CPU cycle, Boom may not be worth it for your needs. For just about everyone else, however, Boom uses a tiny fraction of system resources and it is unlikely that users of Macs built in the last three to four years will notice a performance hit from running the application.
Boom does very few things, but it does those few things very well. Other apps have previously allowed users to boost their system volume, or boost the playback volume within certain applications such as VLC Media Player, but Boom is the most polished and easiest to use that we have yet to come across. Its availability on the Mac App Store, which brings with it the end of software license keys and complicated installations is a welcome bonus.
Boom users need to exercise common sense, however. The volume limits that Apple places on its Macs are there to prevent users from damaging their speakers and their ears. Boom, if used carelessly, can possibly result in damage to both.
While we did not damage our speakers during the brief time we had Boom at its maximum volume, prolonged usage at the maximum Boost level combined with the wrong audio levels on your source material may irreversibly damage your speakers and hearing.
The final factor in considering Boom is the price. At US$6.99 some users may find it a little bit expensive for what is basically a single-purpose application. For users who can’t recall needing more volume from their built-in Mac speakers more than once or twice, Boom may not be worth it. However, for users who frequently wish they could get more oomph from their Mac’s speakers, or for users who need to boost the volume on a number of files, Boom is a great option for turning your Mac’s volume “up to eleven.”