Sleepbox Portable Sound Machine Review

This is the next installment in my white noise machine test and review series.

The Sleepbox is a budget sound machine and one of the few white noise machines with a removable (!) rechargeable battery.  With a weight of only 5.4 oz (152 g) and a small housing (4.3×4.3×1.4 inches) it is very portable indeed.

Here are my observations in a nutshell

The Sleepbox is a very decent budget sound machine if you like water sounds.

It features three different rain sounds, three brook sounds, and three different ocean sounds. Most of these sound pleasant when played through the speaker.

The three ocean sounds are my favorites on this machine.

Like many budget sound conditioners, the Sleepbox plays short sound samples on repeat (in a loop). The designers have managed to implement this fairly well: there are no obvious breaks in any of the sounds as far as I can tell.

The Sleepbox also has a nice lullaby: Brahm’s Cradle Song. I believe this is one that has been used to get me to sleep in my toddler days.

Some samples, however, including the birds, the train, and one of the three brook sounds are so short that I notice a pattern right away, rendering them unusable for me.

The fireplace sounds nice, but needs more variety to keep it interesting.

I like half of the white noises (#1-brown noise, #4-white noise) and fan sounds (#1, #4). These sounds are very decent for blocking/masking environmental noise.

White noise #4 appears a bit harsh, but it is a useful tool: it works quite well together with earplugs to block higher-pitched environmental noise.

In white noise #2 (pink noise) I hear a faint repeating “chirping sound” and in fan #2 a periodic “train sound.” I think these sound artifacts are caused by the looping mechanism. In any case, I won’t use these.

I wish the Sleepbox used longer recordings for the nature sounds and a synthesizer to dynamically create white noises and fan sounds.

In reality, most budget white noise machine manufacturers currently use short recordings.

Operation

The Sleepbox has an unlit 4-direction control button on the top (and a power button at the front). Placing my index finger in the center, I can feel the layout and operate the machine in the dark.

S allows you to cycle through all 22 sounds in the following order:

• Brown noise
• Pink noise
• Blue noise
• White noise
• Fan sounds 1 to 4
• Rain sounds 1 to 3
• Brooks 1 to 3
• Ocean waves 1 to 3
• Birds
• Fireplace
• Train
• Piano piece
• Lullaby: Brahm’s Cradle Song

Selecting a sound is pretty straight-forward, but if you accidentally skip over one, you have to cycle through all other sounds to get back to it.

I would prefer if the sounds were put in three different sound categories, each accessible via its own dedicated button, e.g., white noises & fans, water sounds, and other sounds.

Volume control and maximum volume

I like that the volume can be controlled in fine steps from very quiet to very loud. The maximum volume depends on the sound, but should be more than sufficient for listening to nature sounds.

The max sound power (and frequency spectrum) is important if you want to mask/block environmental noise or completely fill a room with sound.

For the brown noise selection (#1), which I find a useful sound for masking external noise, I measured 69 dBA (1m distance). This is very respectable.

For comparison, I measured a similarly pitched sound on the Lectrofan at 78 dB (i.e., the Lectrofan is almost twice as loud).

The Sleepbox’s white noise (#4) goes up to 80 dB, but that sound is too high pitched for me unless I wear earplugs.

The machine can be set to play sound throughout the night but it also has a sleep timer (1, 2, 3 h). At the pre-set time, it slowly fades out the sound.

It also memorizes the last sound selection and volume.

All indicator lights can be turned off.

I prefer to sleep in complete darkness. The Sleepbox has three white timer LEDs and a blue power indicator. Long-pressing the timer button turns off all (!) lights. This is great.

It doesn’t memorize this setting though, so you have to do it every time you go to sleep.

Power supply, dimensions, and portability

The Sleepbox is light (5.4 oz.) and small (4.3×4.3×1.4 inches) and can be powered via its rechargeable battery, the multi-voltage power adapter that comes with the machine, or another USB power source.

The machine features a standard Mini USB port, making it easy to swap out the power cable should you ever lose it.

What sets this sound machine apart is that you, the user, can remove the battery. When powered by an external source, the battery doesn’t even have to be in the unit.

Using the battery, I get about 26 hours of continuous play time at 50% volume. It takes a bit under 5 hours to fully charge the battery.

I went ahead and checked whether a replacement battery is readily available. I haven’t bought one yet, but googling the number, it appears to be a Nokia feature phone battery.

Review and samples of the sounds of the Sleepbox

The Sleepbox has a total of 22 sounds and focuses heavily on water sounds.

Personally I like its brown noise, fan sound 1, and the three ocean sounds best.

Considering its small footprint, the sound output of the speaker is very respectable. I can crank it up to max volume without noticing any rattling or excessive distortion.

White noises (4) and fan sounds (4)

The first sounds in the Sleepbox are brown, pink, blue, and white noise, in that order:

 

When measuring the sound spectra via the headphone jack, they are very close to the way these noise colors are defined. The bass frequencies are however rolled off starting from about 150 Hz, presumably to not overwhelm the speaker.

Note: Because of the speaker’s frequency response, you are not really getting these noise colors.

*Brown noise

• I like this sound.
• Played through the speaker it sounds higher-pitched than “real brown noise,” but it is a good masking sound to block external noise.

Pink noise

• I hear periodic chirping sounds, probably because of the looped recording, so I won’t use this one.

Blue noise

• Blue noise increases in intensity with the sound frequency (3 dB per octave).
• I couldn’t discern anything that shouldn’t be there, but blue noise in general is too high-pitched for my taste.
• Could be useful in conjunction with earplugs to mask very high-pitched disturbing crickets.

*White noise

• I like this sound when wearing earplugs to mask higher pitched sounds.
• White noise is fairly high-pitched but not as much as blue noise.
• Without earplugs I don’t usually use pure white noise because it carries a lot of hiss. Together with earplugs pure white noise is a useful tool.

Here then are samples of the four fan sounds:

 

*Fan sound 1

• I like this relaxing sound.
• This sound and brown noise mentioned earlier are my favorite masking sounds for blocking external noise.
• In fact, this fan sounds more like brown noise to me (and the brown noise like pink noise).

Fan sound 2

• Sounds not bad, but appears to have a faint repeating train sound underneath.
• Likely an artifact created through the looping mechanism.

Fan sound 3

• Not really my taste.

*Fan sound 4

• I like the motor sound.
• Sounds a bit like a lawn mower with added white noise.
• Decent masking sound.

Water sounds (9)

 

*Rain 1

• Sounds good to me.
• Higher pitched rain.
• Looping is nicely done.
• Good masking sound.

Rain 2

• Deeper rain.
• Unfortunately has a repeating clicking sound underneath.

Rain 3

• Rain on a car roof?
• Can hear the loop.
• I would prefer more variation.

Brook 1

• Sounds OK.
• Some underlying repeating wind.
• A bit more variation would be nice.

*Brook 2

• That one sounds good.
• Can’t detect artifacts or obvious looping.

Brook 3

• Lacks variety: I hear the same pattern repeating over and over.

*Ocean wave 1

• Sounds very nice when played through the speaker.
• Popping sound (around 36 Hz) when played through headphones.

*Ocean wave 2

• Sounds good.

*Ocean wave 3

• Sounds good but not as soothing as the first 2

Birds, fire, and train

 

Unfortunately, I can’t recommend any of these three sounds.

If you are looking for these, the Dreanegg D3 Pro has better-sounding  birds, fire, and train sounds.

(However, I find the water sounds, white noises, and fans better on the Sleepbox.)

Birds

• The birds sound shrill to me and lack variety.

Fire

• Sounds good via the speaker, but lacks variety.
• Repeating triple crackling sound every few seconds.
• When played via headphones, overwhelming low frequency components.

Train

• Nice locomotive whistle but then on an extremely short loop.

Piano and Brahm’s Cradle Song

 

Piano

• Good length
• Depending on your toddler, could make a decent lullaby.

*Lullaby: Brahm’s Cradle Song

Johannes Brahm’s Cradle Song is perhaps one of the best-known lullabies ever.

Even scientific studies have been done on the effect of Brahm’s lullaby on infants.

• I like this lullaby.
• Good length and good looping.

Conclusion

I like 10 (denoted with *) of the 22 sounds the Sleepbox sound machine offers. My favorites are the three ocean sounds, played through the speaker.

There are three effective masking sounds (brown noise, white noise, and fan #1) for blocking disturbing external noise, and the machine goes loud enough for moderate-noise situations.

It is compact and light and can be powered via its removable rechargeable battery (I get 26 hours playtime at 50% volume) or the included multi-voltage AC power. You can also hook it up to USB power sources.

The Sleepbox is a very decent budget travel sound machine. I give it 3.8 out of 5 stars.

Most suitable for:

• Travelers who want a compact budget sound machine focusing on water sounds.
• Users who need to block moderate disturbing noises.
• Parents who want to help their toddler fall asleep with Brahm’s lullaby.

Alternatives:

If you care primarily for white noises, fan sounds, and blocking external noise, the Lectrofan Classic is a much better choice. It has more and better designed white noises and goes louder. If you want to minimize your weight, also consider the Lectrofan Micro 2.

Issues:

• Some sounds, including the birds, the train, the fire, and one of the brooks are on loops that are way too short.
• Some other sounds contain hidden sound artifacts or unclean recordings that can become disturbing. (See review of the sounds for details; the ones marked with a * were fine with me.)
• The first ocean wave sound contains a popping noise (once every minute or so; due to its low frequency this disturbing noise can only be heard via headphones).