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Technical Details

Although really simple to use, SoundBuckets are quite technical inside.  This section is mainly for reviewers and technical folk who want to know a bit more about where we’re at , and why we’ve taken an alternative approach to the rest of the market.

There are  quite a lot of technical details here, so we apologise if it’s a bit dry.

Our Background

Our parent company has been designing top end pro audio gear  for over 25 years, and are well known for making accurate audio gear.  We specialise in making mastering consoles. These are the machines which assemble and manipulate a finished recording prior to it being release as a Vinyl, CD or stream.

To give you an idea of the calibre of what we do, have a look at some of our clients.

The SoundBuckets are our first consumer product, since we worked at the British Hi-FI company Meridian, back in the 80’s.

 

Philosophy

Our big gripe with modern consumer electronics is that most audio gear falls into two categories:

  1. Fashionable life accessories – consumable, replaceable toys
  2. Elite Hi-Fi voodoo magic machines – works of art or snake oil

There just isn’t much stuff in between. Certainly not decent gear that’s been properly engineered to play music well.

When a piece does appear, it’s usually made obsolete within a year or two for the mark 2 model, to keep the companies profits up.

This doesn’t match with how we see the world, we’ve never been a “me-too” company, and we think differently from most.

Our plan for world domination is:

  • Make products to do their jobs well.  A speaker should reproduce music in an acoustic space accurately. That means emotions as well as sounds
  • Make these products sustainable.  That means thinking about materials, lifespan, labour & environment
  • Provide value. You get  the product you deserve for what you paid 
  • Have fun while you’re doing it

Making a small portable speaker work well

There are lots of advantages to small speaker – their small acoustic footprint lets them work better than large speakers for the majority of the frequency spectrum.  The downside is poor bass. Getting good bass out of a small speaker is not easy.

For the majority of the products out there, the entire focus has been on the quantity of bass they can get out of their speaker.  We have focused instead on the quality of the bass we produce.  Big difference.

Getting bass out of a small speaker: how they do it

The main area of focus has been to get as much bass as possible out of a small box. Then make it look pretty.  Or vice versa. Oh, and spend as little as possible in doing it.

Proper bass is expensive. So in order to get cheap bass they have resorted to these technologies:

  1. Small untreated drivers
  2. Passive radiators
  3. Lots of DSP

Small untreated drivers

Normally you need large drivers to get good bass (large surface area).  However the price of drivers increases hugely as you increase their size because they’re mush more difficult to keep rigid.  Plus you need to treat the cones with special damping or use more expensive materials than just paper, to keep the driver linear across the frequency range.

Finally, if you have a large driver, you’ll need a tweeter as well for the high frequencies, as the big drivers can’t reproduce the high frequencies properly.

So if you can use small untreated drivers, your box can be smaller, and your costs too.

Passive radiators

To get bass from a small driver, you need to reflex load it.  A passive radiator lets you do this in a small box. Essentially it acts as an acoustic amplifier, increasing the output from the smaller main driver at low frequencies.  All well and good, except that it’s difficult to tune a small box, so you tend to get an uneven bass response, with a sharp peak as the radiator resonates.  Coupled to this, the bass drops off rapidly below this peak, and the radiator tends to flap a bit because it’s not loaded properly, or driven.  However it does extend the bass response.

Lots of DSP

To get over the wobbly frequency response and poor bass output, DSP is used to cheaply correct the frequency response, and boost the bass output to get a decent low bass output.  Technically this works, except that you can only correct so much, the driver will still misbehave, and you run out of headroom at higher volumes, so the bass has to be reduced.  Sometimes dramatically -up to 20dB less.  DSP is a great tool, but you need expensive DSP chips and good drivers to get the best response.  You aint going to see this in the mass market.

Getting bass out of a small speaker: how we do it

We start with a slightly bigger box.  We use a powerful large bass driver combined with a tweeter. The box acoustic volume is perfectly tuned, and the drivers are hard driven by a bi-amped system.

The bass driver has 16x the area of a 1″ driver, and 4 x the area of a 2″ driver, so automatically connects to the air better, and goes lower by itself.  The sealed box drops off at half as fast as a reflex/ passive radiator does, and is perfectly damped, so the driver doesn’t flap, or peak.  The box is properly acoustically stuffed, so the mechanical and electric Q’s are perfect.

Because the driver is a quality part, we don’t need to apply any frequency correction, apart from a Linkwitz-Riley 4th order analogue active crossover.  We also don’t boost the bass, because we don’t have to.  This means that we don’t run out of headroom as the volume increases, so the bass level is never reduced with volume.

The result is a deep, tight rhythmic bass, that goes low, sounds good and punchy and keeps getting louder as you turn up the volume.

 

Off axis

SoundBuckets are very linear off axis, so illuminate the room in a consistent manner at all angles.  They are onmi by design to about 3500Hz, then gently focus to 20KHz, where the front to rear patterns are only 15dB different.

This is achieved by the physical arrangement of the drivers and timing circuitry in the crossovers. Helped just a bit by the curved sides and accuracy of the drivers.

What does this mean?  Well we hear reflected sound as well as direct sound, and it’s this reflective sound that gives us a sense of depth and realism to the music.  This is one of the reasons that headphones sound dry and artificial – there’s no reflections.

The even distribution of sound at all angles means that the reflections are also even, and build a positive picture of the music in your brain. In contrast, irregular reflections jar a bit, and tend to distract your listening pleasure.  As a side effect of this wide dispersion, we’ve dropped the on-axis HF response slightly to provide a flatter wide angle aggregate  response.

One interesting effect of DSPing a poor quality speaker, is that the drivers radiate different levels at different angles.  You can correct the forward angle, but you can’t equalise all the angles.  This results in irregular reflections.

 

Analogue beauty

Because we don’t use DSP, the insides of the SoundBucket are completely analogue.  If you put 24 bit 192K music into the analogue aux socket, it will transfer this perfectly to the speaker drivers.  No up/down/ re-sampling or bit reduction, or dodgy compressors or filters. Just perfect reproduction.

Little details

The SoundBuckets are stuffed full of little details, sonic and user benefits.  Here’s some of them:

  • The SoundBucket is stuffed with British sheep wool to absorb internal reflections, for a cleaner sound. Sheep wool has been used for decades as the perfect absorber for speakers, but is fussy to use and expensive.  Get it right, and it’s worth it though.
  • The cylindrical extrusion vibrates less than regular flat panels, so the cabinet output is lower than a rectangular box speaker.
  • The rubber feet on the bottom of a SoundBucket are screwed on, not glued, so they won’t come loose over time.
  • The top grille of a SoundBucket is removable, so you can see the bass driver working.
  • The whole SoundBucket assembly can be disassembled with a normal screwdriver, so it’s easy to repair and recycle
  • The leather strap is made from British leather, cut, shaped and stamped by us in our workshops
  •  Supports aptX-Low Latency for movies &  Xbox etc, so you get perfect lip-sync
  • On standby, connected to the mains, it consumes less than 0.25W (2KwH a year)
  • The external PSU meets the latest level VI power efficiency
  • The SoundBucket is also available without Bluetooth for pro clients
  • Full remote controllable via Bluetooth for forthcoming app
  • It automatically re-connects on power up to previous device it was connected to
  • It automatically searches for any other SoundBucket close by, on power up to stereo pair to them
  • When stereo linked, all other features are linked too
  • If you tap the lid, the music level dims so you can talk over it. However it also boost the bass by 15dB  (like an old fashioned loudness switch), so it sounds good at low volumes too.

Tech Specs

Power

  • Internal large lithium 35WHr batteries
  • Battery life >40 hours at 60dB SPL, > 8 hours life at 85dB SPL @0.5m
  • Battery rating: >500 charge/ discharge cycles
  • USB charge: 5V @ 0.5A
  • Mains charge: 24V @ 1A
  • Charge time varies on method and battery condition, but typically 4-16hrs

Bluetooth

  • Bluetooth Version: 5.0
  • Audio codecs: SBC, AAC, aptX & aptX low latency
  • Range: 5-30m, depending on obstacles
  • Autoconnect to last device on power up
  • Always connectable, just search to pair
  • 8 pairing stored in memory, for easy connection
  • TWS true wireless stereo linking to another SoundBucket
  • Up to 3 devices can be connected at once

Audio

  • 16mm (5/8″) tweeter and 115mm (4.5″) bass/ mid driver
  • Pure analogue path with analogue crossover and bi-amped 2x 70W power amplifiers
  • Max continuous power amp output RMS 50W Bass, 25W Tweeter.  Peak power output 100W Bass, 50W Tweeter
  • SPL level on batteries without clipping (AES pink noise): > 86dBC RMS, 100dBC Peak @ 1M (92dBC RMS, 106dBC Peak @ 0.5M)
  • SPL level on external power without clipping (AES pink noise): > 92dBC RMS, 106dBC Peak @1M (98dBC RMS, 112 dBC Peak @ 0.5M)

Responses

  • Frequency response on axis, ref 1KHz: +/- 3dB 85Hz-20KHz, at all playback levels unlike other speakers
  • LF Frequency response, ref 1KHz: -3dB @ 85Hz, -10dB @ 50Hz
  • System damping is optimal @ Q = 0.707
  • Extended Bass, rolls off at half the rate of other speakers, so you hear more more low bass
  • Wide, even dispersion for balanced engaging sound in real rooms

Graphs

Frequency response

THD