2U4U DMR-300 WMA Player — THG.RU

Introduction

Over the past few years there has been a wave of MP3 players hitting the shelves. From Intel to Creative, the range of each player’s capabilities and characteristics has been broad and extensive. But now, a new player boasts the ability to record WMAs in real-time without the need of a computer. This sort of portability allows those who are less computer savvy to own and manage a portable audio player.

Physical Overview

One of the physical attributes of the 2U4U is its weight. The 2U4U is incredibly light. To give a reference point, the tiny Nokia 8260 phone noticeably outweighs the player — not a bad quality for those who are looking for a lightweight player. The dimensions are small, roughly 1.5″ x 2.5″ x .3,» making it very portable. The buttons push in nicely and everything is labeled as needed. Overall, the compact look and feel is appealing and impressive. The only two shortfalls are: 1) the small unimpressive LCD screen — a slightly bigger, color screen would have been nice; and, 2) the unit runs solely on two AAA batteries, meaning it is not rechargable by just plugging into the wall.

Package

The 2U4U comes standard with a few accessories. The included items are:

Remote Controller

Stereo Earphones

USB cable

Line-In cable (mini to mini)

Battery (AAA x 2)

Installation CD

Manual, necklace, and carrying pouch

Storage: Not Too Big, But Expandable

The 2U4U comes equipped with 128 MB of internal storage. With most tracks ranging from three to four minutes, the player on its own can hold roughly 30 to 40 songs. The storage capacity can be expanded using SD/MMC memory cards, and with the size of SD cards expected to reach 1GB by the end of the year, this added feature is not only convenient, but crucial to the long-term value of the 2U4U.

Controls

There are a total of eight buttons on the 2U4U:

• Play/Pause (Hold down to stop)
• Track Forward
• Track Back
• Volume Up/Down (lever-like button)
• Record
• Menu
• A->B loop
• Hold

The menu function took a while to understand. After pressing the menu button once, pressing the menu button takes you through each menu option. The «Track Forward» and «Back» buttons allow you to change each menu option. Pressing «Play» finalizes your change. Other than that, the buttons and controls are rather intuitive.

Connection

The 2U4U connects to the PC via its built-in USB interface. Its box claims a MAX of 4 Mbits per second, and it stays true to the claim. In fact, the transfer rate holds at 4 Mbits and never seems to drop below the mark, resulting in a four to five second transfer time on average per song.

Recording Quality: Not Too Shabby

The most boasted feature of the player is the ability to record WMAs in real time, be it from the internal mic or the direct line-in.

The microphone quality is surprisingly good. From across the room, the mic picked up voices fairly well, better than most mics of the same form. At the 8 kbps, from around two feet away, the WMA recording was a little noisy, but definitely clear enough for practical use. At 128 kbps, the microphone recording was clear with a few sound artifacts from the compression.

The quality of the direct recording through Line-in was as expected. To test the WMA recording quality, I set the recording bitrate at 128 kbps, so that I could compare it against the same audio track encoded on the PC at 128 kbps in MP3 and WMA formats. I connected a CD-player to the Line-In port of the 2U4U and recorded a track in real time. The resulting 128 kbps WMA file was of lesser quality than the 128 kbps WMA I encoded from the same audio track on the computer. The WMA file recorded in real time contained more artifacts and was a little bit noisier than the PC-encoded version. Though the artifacts were a smidge distracting, the overall quality was acceptable.

Compared to the MP3 recorded on the PC, the real time-encoded WMA file was of lesser quality. The PC-encoded MP3 was cleaner, and had far fewer audio artifacts. The PC-encoded MP3 and WMA tie in terms of quality. The MP3 was a bit quieter, but played clearly and had very little noise. The WMA, however, had a brighter sound, but had more audio artifacts than the MP3.

Compressed Audio, Genesis: The Beginning and The Era of MP3

A little under ten years ago, MPEG-1 layer-3 audio compression technology hit the technology community and, a bit later, the Internet. The ability to encode a 30 Mbyte .wav CD audio rip into a file around 3 Mbytes was not only space saving, but amazing in its own right.

The MP3 era had begun. Websites/services such as Scour.net allowed relatively easy sharing of music files over the Internet. MP3 soon became part of the Internet vernacular as well as most Internet users’ music library. With the adoption of Napster by the masses and the following creation of the «Napster Music Community,» MP3 became the most widely accepted standard for compressed audio.

WMA: What Microsoft Has to Offer

Through recent releases of Microsoft Media Player, Microsoft has been trying to push its coveted WMA compression codec. The codec boasts higher quality and smaller file sizes at the same bit-rate of a comparable MP3. Microsoft hopes to win the hearts of the Internet audio community by providing encoding and decoding tools free to owners of Windows.

Dolby’s Creation: AAC

AAC (Advanced Audio Coding) is Dolby’s offering to the music community. ACC intends to offer «up to 48 channels of audio, sample rates of up to 96 kHz, and can achieve ITU-R broadcast quality at 320Kbps for a 5.1-channel audio program,» according to various press releases. Compared to MP3, it claims to be of higher quality, at roughly 30% less storage space and bandwidth. It has been standardized under the MPEG-2 specification.

As the time from AAC inception grows, so does the number of its supporters. Various software and hardware companies are jumping on the bandwagon to develop and manufacture products that support AAC.

Audio Comparison: Putting MP3, WMA, and AAC Under a Microscope

Creating an audio compression codec is not an easy task, and neither is analyzing its results. Thankfully, there are tools today that help make this task easier.

CoolEdit provides a good frequency analyzer. Using the frequency analyzer, it becomes easy to tell the effects of each codec on the original audio track: 4.wav. I took a snapshot of the three encoded files at the same point in the track. This allows apples to be compared with apples.

The above picture is the frequency analysis for the original audio track «4.wav.» The vertical axis is in decibels and the horizontal axis is in Hz. The human ear can hear between 20 Hz and 20 kHz.

Audio Comparison: Putting MP3, WMA, and AAC Under a Microscope, Continued

The MP3-encoded version (in red) of the track had some interesting properties. It seems that the compression algorithm had cut off all sound above 15.8 kHz. This technique is useful in shrinking the resulting MP3 in size and banks on the fact that very little of the sound resides in 15.8 kHz+ range. The leveling of the audio at low, mid, and high frequency appeared to be flat.

The AAC file (in blue) as shown by the graph, held pretty much true to the original wav file in terms of level at low, mid, and high frequencies. The only major deviation from the WAV file was in the 20 kHz+ range, which we cannot hear anyway.

The results for the WMA file in the frequency analysis were quite good. Like the ACC file, the leveling of the WMA seemed to have a high fidelity to the original track. It had, however, a curiously low frequency cutoff at around 14 kHz, well within the range of human hearing.

The frequency analysis alone cannot tell which file format is better or worse. What is becoming obvious, though, is how the MP3 file stands out from the other two files in terms of lower level fidelity. These signs definitely show that MP3 is aging.

How Does It All Sound?

If the three formats had to be ranked according to their quality/size ratio, the order would be AAC, WMA, MP3. After listening to AAC and WMA, the sound quality of MP3 is not up to par. As for AAC and WMA, the biggest difference was clarity. At the same bit rate, AAC offered a clearer and closer sound to the original, beating out WMA. WMA definitely sounds better than MP3; its sound is a bit more vibrant.

The Future: MP3, WMA,….AAC?

What the future holds for MP3 seems to be clearer and clearer as the months pass. As MP3 continues to age, it is becoming increasingly apparent that it is living on borrowed time. As for WMA, the future is not so certain. Will Microsoft’s codec be the future of compressed audio and portable audio devices, or will it be the relative newcomer AAC? MP3’s current strength lies in its wide acceptance and software support. The current encoding and decoding algorithms are extremely fast, and — most importantly — widely available for free download. WMA has its strengths, though, given that Microsoft owns the rights to the codec, which allows Windows users the ability to easily encode to WMA without using additional software. AAC is what Dolby Laboratories has to offer to the «market.» It claims to have five-channel sound at incredible fidelity to the original audio source, with the resulting file being 30% smaller than an MP3 encoded at the same rate. The problem is that it has not been as widely accepted as MP3, or even WMA. Trying to find software to either encode or decode an ACC file is difficult and can be frustrating. But with more and more companies adopting the AAC standard into their own portable audio players, AAC may be the future.

Conclusion

All in all, the 2U4U is a good product. Nothing too exciting, but it certainly has its moments. It does what it claims to do, and does it well. The real-time encoding/ recording abilities worked surprisingly well and resulted in a satisfying quality WMA encoding. And, with a $199 price tag, it’s a financially feasable solution. If you are looking for an extremely lightweight portable audio player with microphone and line-in recording abilities, then you might just want to look in the 2U4U’s direction.