Below you will find answers to top questions.
WHAT IS THE SUBPAC?
WHAT IS THE SUBPAC?
The SUBPAC is a high-fidelity physical sound system that quietly and directly transfers low frequencies to your body, providing the physical dimension to sound. As you lean against it (seated version) or wear it (mobile version), you will experience a fully immersive music/sound dimension that truly is the natural, logical progression to the sound experience.
Yes and No.
Yes, there are other products that deliver ‘vibrations’, but No – SUBPAC stands alone in its attention to musical nuance, quality and delivering an experience that countless music professionals and sound designers stand behind. Find out more at feel.subpac.com
You can buy both versions of the SUBPAC, the S2 studio/seated version and the M2x mobile/wearable at shop.subpac.com.
The short answer:
- Save hearing
- Total immersion
- Save money
- Room issues
For the full answer: CLICK HERE
The S series is designed to be used in a seated/stationary environment. The M series was designed to be used in a live/mobile environment. The core technology (power, transducers, circuitry, membranes etc) are the same, but the difference in form factor makes it ideal for its different uses. The S series has a wider surface area, and this creates a somewhat broader experience.
Both will change the way you experience music and sound forever, it just depends what your primary applications are. The S1 and M1, and M2 will not be produced anymore to make way for the S2 and the M2x product evolution.
The SUBPAC is quiet. With ambient noise in the room it cannot be heard. In a room that is dead silent with the SUBPAC turned up at high levels, there will be some noise – however not enough for someone in another room to hear. In a café, on a plane, or in a car – again these are places with ambient noise – the SUBPAC cannot be heard.
SUBPAC’s tactile transducers operate similarly to a speaker but vibrations are conducted through the SUBPAC’s vibrotactile membrane rather than through the air. The result is an accurate, powerful and immersive experience that traditional speaker systems cannot achieve.
This is a combination of factors:
- In addition to receiving the physical dimension, your body perceives the frequencies as hearing because part of the vibrations travel through your body and to your inner ears. This is a benefit of the SUBPAC because it’s an extension of hearing, not just something on you feel.
- You are closer to it than other people. So you can hear it a bit but it still is silent to other people in the room and to your neighbors.
Sounds like thing’s are running a little hot and it’s causing your unit to shut off!
A great SUBPAC experience starts with making sure your SUBPAC is tightly secured using the chest and waist support straps and has a healthy battery charge. If you’re using the SUBPAC S2, please make your chair has a firm backing.
For headphones, If you happen to be using high impedance headphones, it’s recommended that you drive those separately from the SUBPAC. High impedance headphones need a much hotter level to drive to a moderate listening level, however, the majority headphones will be suitable to drive through the SUBPAC headphone output.
Please note that the SUBPAC INTENSITY is relative. INTENSITY is a sum of your device/input volume and the INTENSITY knob position. If you enjoy listening at higher levels, your INTENSITY knob may only need sit around 20%-50%. If you prefer lower to moderate listening levels, then it’s okay to turn the knob a bit higher to 40-70%. It’s very rare that you would need the knob set at 80-100%, but in some cases it may apply.
If you have gone over all these steps, you should be having an OPTIMAL experience and will avoid any device clipping or cut outs. Remember, clipping is not more BASS, clipping is squashing the dynamic range.
If you need more volume or BASS, please reach out to our product specialists who can offer some other SUBPAC tips and tricks!
WHO’S BEHIND SUBPAC?
WHO'S BEHIND SUBPAC?
The initial production of SUBPAC was made possible by a Kickstarter campaign that raised over $100,000 in April 2013 and sold out within a few months of debuting online.
SUBPAC is a product of StudioFeed, a social venture that supports independent music through technology development and community engagement.
We have assembled a group of supporters that literally gave birth to, and innovated many of the genres we all enjoy today – from Dub to Techno, Funk, Drum and Bass, Dubstep, Industrial, Hip Hop and others. These artists are rarely/never seen ‘endorsing’ a technology – this underscores our commitment to changing culture – from hearing music, to feeling music.
Well, In order to change the culture from hearing sound, to feeling sound – we thought what better way than to bring it to the world with some of the most important music makers on the planet. Unlike some other audio companies (you know who you are) – we do NOT PAY our supporters for their endorsements.
We literally went door-to-door to many of the artists you see on our site, their studios – to explain to them the merits of tactile sound, in their studios and for their fans. It’s not a surprise when you show a technology that provides a much-needed solution to the studio environment, in addition to allowing their fans to realize the true impact of their music a wholehearted embrace follows. Simply put, music makers and sound designers want the physical dimension of sound – the SUBPAC – to be a part of our music and sound experience.
There are two main developers: Sarosh Khwaja (material science focus) and Andrew Kilpatrick – designer of critically acclaimed modular synthesizers and other audio products (kilpatrickaudio.com). The combination of these two individuals, in addition to a support staff that includes engineers, producers, musicians and designers, resulted in the creation of the SUBPAC.
HOW DO I USE THE SUBPAC?
HOW DO I USE THE SUBPAC?
The SUBPAC’s rechargeable lithium-ion battery charges when you plug the SUBPAC into a wall outlet and turn the SUBPAC into the “On” position. A SUBPAC is turned on when the GREEN light on the Control Box turns on.
POWER INDICATOR LED STATES:
S2 2019 Edition
- Solid Green – S2 2019 is fully charged if plugged in / healthy level of charge if not plugged in.
- Solid Blue – S2 2019 is plugged in and is still charging
- Solid Red – S2 2019 is running low and should be charged soon
- Blinking Red – S2 2019 needs to be charged immediately OR the unit is being overdriven. A full charge takes around 2-4 hours and will last more than 8+ hours depending on the frequency and intensity of use.
- Solid Green – M2x is power on, not low battery
- Solid Blue – M2x is plugged in and charging
- Solid White – M2x is plugged in and fully charged
- Solid Yellow – M2x is running low and should be charged soon
- Blinking Red – M2x needs to be charged immediately OR the unit is being overdriven
M2 / S2
- Solid Green – S2/M2 is fully charged/charging complete when plugged in
- Solid Blue – S2 is plugged in and charging
- Solid White – M2 is plugged in and charging
- Solid Yellow – S2/M2 is running low and should be charged soon
- Blinking Red – S2/M2 needs to be charged immediately OR the unit is being overdriven. A full charge takes around 2-4 hours and will last more than 8+ hours depending on the frequency and intensity of use.
For our legacy products (S1 and M1)
When the SUBPAC is charging an additional ORANGE light, next to the GREEN light will turn on. When the ORANGE light turns off, the SUBPAC is fully charged and may be unplugged from the wall. A full charge takes around 2 hours and will last 4 to 6 hours depending on frequency and intensity of use.
SUBPAC is similar to the invention of the subwoofer, or surround sound. Although it was designed with an intellect, heart and soul for music – music alone is not the only use. We do not want to limit the potential of the physical dimension of sound.
Yes! SUBPAC has helped many Hard of Hearing people experience music and sound. It’s also an elegant solution to hearing loss/tinnitus issues. The vibrations of SUBPAC are conducted through your bones – the most effective way of delivering low frequencies.
Yes. The SUBPAC S series, seated, is meant for you to sit down and lean back into. The SUBPAC M series, our mobile units, are worn like a low-profile backpack. Both models rely on direct contact with your body, a key factor in properly experiencing the product.
Just plug your headset into the SUBPAC and plug your audio cable into your mixer, soundcard, smartphone, MP3, tablet, laptop, gaming device, or any other audio source with a standard 3.5 mm jack (or use a 3.5 mm adapter for the cable you are using).
WHY DO I NEED A SUBPAC?
WHY DO I NEED A SUBPAC?
The S2 was designed for the seated person – in the studio, in the car, sitting in front of a screen (too much of that in life, really). Its body coverage gives you a more immersive experience whose tactile transducers sit lower on your body, it resonates with your body and chest.
The M2x designed for the mobile user. Are you standing up? Are you in transit? Are you dancing at a silent disco? The M2x is for you. It sits a little higher up on your body and resonates with your chest and shoulder region.
If you’re a DJ (either playing gigs or working in your room), you need to feel what is going on in your mix. You need to experience what the crowd is experiencing – headphones are not enough (and you’re killing your ears cranking the levels) trying to hear/feel what’s happening. Please, strap on a SUBPAC M2x and monitor your music the right way – by hearing AND feeling it. Experience what the crowd is experiencing and save your hearing.
When you’re sitting, you want a fuller/broader experience one that you can lean off of if you want (though you probably won’t). For that reason, we designed the S2.
The SUBPAC was built to accurately deliver low frequencies to your body for the most immersive sound experience you have ever had. When you connect your games you will feel your environment. You can feel people coming before you see them.
When you feel sound it gives you the sensation of a loud system. You won’t need to crank your system to feel immersed. Most large systems/clubs have lower powered subs/bass vs treble/mids (for noise complaints or other reasons). Because of this, in order to attempt to deliver you a full sound, the mids/highs are cranked, which kills your ears.
With a SUBPAC, you can adjust the physical bass element and keep your mids/highs (i.e. headphones/monitors) at whatever level is optimal for you.
The SUBPAC, tactile sound, is an elegant solution to the under-appreciated hearing loss/tinnitus issues plaguing those who appreciate music. When you feel the music you don’t need to push your ears to give you that immersive experience. The vibrations of the SUBPAC are conducted through your bones – the most effective way of delivering real bass.
The SUBPAC can be taken with you with. The SUBPAC M2x is a wearable/ a mobile unit, and the SUBPAC S2 can be easily placed into a backpack. Have you ever walked around with a big club system coming with you? It’s fun, trust!
SUBPAC: You know the answer 😉
Yes, its that good. For a few hundred dollars every piece of music you have ever owned that has a full sound will be rediscovered – any new music will be delivered the way it was intended to – with the energy of the low frequencies physically felt in a visceral way (while not disturbing anyone around you). Every day that passes and you don’t experience the SUBPAC is one where you could be.
That experience of being at a jazz club and feeling the bassist walk up and down the frets, the drummer bang out a funky break, or being at that symphony with the powerful tympani and contra-bass movement – it hit me in the body – it felt right. The SUBPAC delivers this physical dimension that makes the live experience separate from a life-less ‘headphone’ or ‘docking station’ listening session. If it doesn’t hit your body, its not real bass. You’ll see what we mean when you connect to a SUBPAC.
Unless you have a well- treated room with high-end traditional monitoring equipment monitoring bass will be a problem. Your room becomes the main barrier between you and accurate monitoring. By eliminating the room and delivering bass frequencies to your body, you can determine what parts of the body you are hitting with your sonic masterpiece.
Bass is meant to be felt. Further, properly balancing the different elements in your low end (kick, bass, sub etc.) is more effectively perceived when you feel the balance of the mix. Check out the artists who are supporting the SUBPAC – this group which will continue to grow have defined a lot of the music we listen to today.
The SUBPAC is tactile sound. The significance of this is you can feel the physical dimension a live audience would feel with a proper sound system. Your neighbors will not hear the low frequencies that get to them. With headphones or studio monitors the music experience is complete – anytime of day.
The SUBPAC delivers the physical bass that the crowd gets. When you connect to the SUBPAC you can rip it up behind the decks with the full club experience.
The SUBPAC accepts a line in connection from any professional output in your studio. The connection is a mini jack to save space in the box with the goal of making it lightweight and portable. This is easily adapted to any other connector on your interface.
Yes. The SUBPAC is a versatile studio tool that is effective during all stages of production. From inspiring the vocalist in the booth to editing and programming, you will find it useful anytime you need crystal clear accurate monitoring of low frequencies.
Use the SUBPAC to help train your body to answer this question. Good productions strive to present the listener with a balanced feeling between the frequency ranges. Here is how David Alexander from Icon Collective explains it to music production students:
- Select a song similar in style / production and preferably in the same key as the track you are mixing / producing.
- Before turning up the SUBPAC, adjust the volume of the reference track in your main monitors so that the Kick Drum in the reference song is the same volume as the Kick Drum in the song you are mixing / producing.
- Now turn up the SUBPAC and play the reference song while you increase the intensity dial of the SUBPAC until you find a level that suits your taste.
- Next use the SUBPAC (without adjusting the intensity dial) to compare the reference song to your song / mix and make adjustments accordingly, striving to match intensity and volume in the Sub-Bass and Bass frequencies of your song / mix to the reference song.
The SUBPAC has only one control. The response of the SUBPAC and the setting of the intensity knob depend on the users body mass and bass preference. Your body has to learn the setting. This is why we left the knob continuously variable. Click the link to listen to this calibration recording first to get your SUBPAC and headphones set for the best tactile/dynamic range.
Now follow these four steps to check yourself during production.
1. Select a song similar in style / production and preferably in the same key as the track you are mixing / producing
The SUBPAC does not alter the phase of the signal. Waveforms projected from the headphones and the SUBPAC are 100% in phase with each other. There are many recordings released with phase problems in the range of tactile sound. Just like trying a set of high end speakers or headphones, the listener will be drawn to “new” sounds in a favorite old recording. You can monitor these timing differences with the SUBPAC in great detail. It is easy to detect sloppy production habits like edits not starting a zero crossings and layered samples clashing with each other, etc…
Waveforms projected from monitor speakers and the SUBPAC will be experienced at a small delay depending on distance. In air, sound takes around 1ms to travel one foot (a very rough approximate that depends on environmental factors), the SUBPAC will feel earlier by this small amount. In most studios you will have to really concentrate to notice this because we are already programed to compensate for this delay. Remember that sound travels much faster through solid objects. If your speakers are resting on furniture, you will feel them before you hear them. At large distances or in theaters where the speakers are very far away, the delay will become very obvious. This is all easily corrected by inserting a software delay to the SUBPAC to line the signals up.
Connect the SUBPAC using a parallel output on your interface (headphones, aux out, monitor out, etc..) that contains the same signal as the master. Inside the DAW add a second output track that can host an eq plugin that can function as a low pass filter. Send this track to the output that is connected to theSUBPAC. Adjust the low pass filter to your preferred frequency. Here is a video with an in depth explanation
The SUBPAC is designed to transmit only the tactile frequencies from 5hz to 200hz. The box does not alter the audio, it passes all frequencies directly through to your speakers or headphones. Your brain acts as the crossover when your body can feel the bass from the SUBPAC.
Most speaker systems need crossovers. The amount of energy required to produce air vibrations for us to feel can cause distortion in speaker drivers. This problem can be solved by adding multiple drivers that each handle a different area of the frequency spectrum. A crossover is used to separate the signals so the speakers can work efficiently. In tactile sound there is no transmission in the air. Your brain combines what is felt and what is heard into a full frequency experience. In this case you become the crossover, the smartest crossover on the planet!!
In the studio environment, the audio interfaces have many outputs that can carry the same signals. The engineer can configure the computer to send identical signals to the SUBPAC and to the speakers at the same time. This advanced technique allows for greater flexibility for monitoring different speaker sets.
You are directly attached to a premium bass monitoring system. You will begin to notice a whole new frequency spectrum of sound. As a music producer, edits and mixing decisions that would only be heard on large club systems are brutally obvious in the studio. This makes the SUBPAC a valuable tool for understanding and feeling your productions.
THE SUBPAC S2
Some later model SUBPACs incorporate an ‘auto-off’ feature where the SUBPAC will turn itself off automatically after 30 minutes of no audio being present. This feature is intended to protect the life of the battery by making sure the unit does not stay on while it’s not in use.
The intensity curves of the SUBPAC S2 and M2 (M2x) are linear in response from 0 – 70% for maximum accuracy when writing and mixing making it an extremely accurate and effective tool for high end professionals.
From 70% to 100% we have applied a logarithmic curve which rapidly increases the intensity in a non linear fashion allowing for an enhanced bass response for those looking for a less accurate but more bass heavy listening experience. In this way we have accommodated the requests of some of the most respected music producers in the world while at the same time respecting the wishes of the many music fans that have sent us positive feedback based on their experience with the previous SUBPAC S1 model.
The 0-70% range and the 70%-100% ranges are both useful for professional use and casual music listening as they provide 2 different ways of feeling the music you love. Use them as both different modes of appreciating your music, but also as an A/B tool when used with reference material you know well. And of course please feel free to send us feedback to let us know your thoughts – after all the new SUBPAC models have been designed and created for you. Enjoy!
We ship an international adapter with four different plug cables (US, UK, EU, AU) that covers most of the world. If the country you’re in uses some other cable, you can buy a IEC-C7 cable locally and use that.
The S2 was not designed to be sat on – the experience we deliver relies on the SUBPAC being in direct contact with your back.
The SUBPAC S2 will work either either using the standard 1/8″ line input cable or, the Bluetooth 4.0 connection. You cannot use both connections at once. If Bluetooth is running and paired, connecting the line in cable will disable Bluetooth and switch over to analog in.
We do not recommend using the Bluetooth connection while mixing in the studio or performing live. This is due to the latency (delay) factor of between
Bluetooth however is ideal for listening to your music wirelessly!
40-150ms depending on your the format of the source audio.
They both use Bluetooth 4.0 and stream audio via the A2DP protocol.
The strapping system is designed to accommodate the broadest range of chairs possible. The straps are removable and the S2 is completely functional without them.
- Frequency Response: 5Hz – 200Hz
Wired Line Input: 3.5mm stereo
Wireless Input: Bluetooth 4.0 with A2DP Streaming
Headphone Out: 3.5mm stereo
Rechargeable Battery: 10.8V, 2300mAh 3-cell Li-ion battery (8+ hrs use)
Charger: 15V 1.6A 24W adapter with international IEC-C7 cables
Dimensions: 17″ x 12″ x 1.5″ (430mm x 305mm x 40mm)
Weight (including battery): 4 lbs (1.8kg)
New Features Include:
- New materials and design for enhanced vibratory field
- New optimized tactile transducers for improved accuracy and power efficiency
- New ergonomic shape for maximum contact and longer sessions
- New 3-point, removable strapping system to maintain optimal placement on your chair
- Slimmer control box with flexible strapping to secure it to your chair
- Flexible control cable for easier control box placement
- Bluetooth 4.0 input with A2DP streaming
- High capacity Li-ion rechargeable battery – now runs 8+ hrs per charge
Yes, you can! The SUBPAC S2 should be able to easily slide into most knapsacks allowing you to take your BASS from the studio to the streets.
SUBPAC M2X (Specific)
SUBPAC M2X (Specific)
If you’re looking for more dynamic range, an even cleaner signal and longer battery life, this upgrade is for you. If not, our products have always been designed for pro use so you are good.
The M2x has increased dynamic range (more natural and open feel), and less harmonic distortion (cleaner sound at higher levels) and a significantly longer battery life.
With the M2x we have increased the dynamic range, which means you now have a more open, accurate and natural representation of your music. This is especially helpful when working with acoustic instruments and passages with lower overall volumes.
We have reduced the harmonic distortion (unwanted higher and sometimes audible frequencies that come from driving the system hard), to give you better definition even when you’re monitoring at higher levels.
We have lowered impedance of transducers and upped the power of the whole system so you get a stronger, clearer, more sensitive signal.
The connection range and reliability of the M2x Bluetooth has been improved.
Although there have been many improvements made on the new SUBPAC M2x, we wanted to make sure there was no surprises in the cost! New and improved, for the same price of $349.
The SUBPAC battery is rated for 8+ hours but performance will vary depending on source material and intensity levels.
THE SUBPAC M2 & M2X
SUBPAC M2 & M2X
The upgrades the M2x include:
Increased dynamic range which gives a more open, accurate and natural representation of your music especially for acoustic genres, lower total harmonic distortion which guarantees a better definition even at higher levels, and a huge 8+ hours of battery use time.
Yes, the M2 and M2x both share the same form factor. The size, straps and weight are the same on both units.
Although the M2 provides a highly accurate and impactful experience, some M2 users should definitely consider upgrading to the M2x. If you are DJ, producer, sound designer, audio engineer, or work with audio in any way, you will benefit from the added power and accuracy of the M2x.
Napping with bass is incredibly relaxing but we recommend laying on your stomach to prolong the life of the product. The extra pressure and heat can lead to malfunction.
The chest strap is one size fits all and can be removed if desired. If you are having trouble with the chest strap not fitting, lengthen the arm straps so they can be drawn together by the chest strap. To remove the chest strap, simply pop it off its track by sliding down and pulling away.
The M2 and the M2x are both a fantastic way to monitor low frequencies onstage. It will connect to a variety of line level sources including instruments, DJ mixers, in ear monitoring systems, and wireless receivers. Bluetooth connections do not have the fidelity or latency for time critical stage use.
Laying on your back with it on or falling from a high place.
Heat build up. Let it cool off if you notice it getting hot.
Cord strain or port damage from accidental disconnects.
Full intensity, full source volume, with lots of heat and pressure for long periods of time (take it easy tiger!!)
Yes. When you lean against a chair back you will notice a slight change in response. This is due to more pressure between the chair and your body. Depending on the chairs physical properties, some resonances will be added or subtracted to the response. This will not damage the M2 or the M2x.
The M2 and the M2x are rated for headphones rated from 32 ohms and below. High impedance studio headphones should be connected to a dedicated headphone amp through an audio interface that can serve the M2 or M2x with its own output.
The M2 and M2x both use a 1:1 Bluetooth streaming connection. You will have to choose one transmitting device and one receiving device. Some newer mobile devices such as the Samsung S8 can stream to both devices. (SUBPAC and Wireless Headphones)
It’s perfectly fine to fly with the M2 or M2x. This actually makes travel an amazing musical experience. There aren’t any restrictions around using this technology during a flight except for the electronics rules during takeoff and landing. The SUBPAC will make your flight go by in no time!
The amount of level you feed into the SUBPAC from your source device directly affects the bass output of the unit. For example: You have set your phone’s headphone level to just under a quarter way up. You can hear music playing softly through the SUBPAC but you want to feel more bass. So you turn up the intensity level and quickly run out of room. It’s maxed out. To feel more bass all you need to do is turn up the source. But now it is uncomfortably loud in the headphones but the bass level is good. The best thing to do in this situation is use headphones with a built in level control. This will allow you to turn down the music to the level you need, but also feel the full range of bass dynamics.
Yes, bass is an important part of life. The M2 or M2x will bring bass into all your activities. The only limitation would be activities that involve water or laying on gym equipment (weight machines, etc..). Any activity that involves mechanical machines that the wires may become entangled in is not recommended. Be safe, but bring the bass.
Do not immerse the either unit in water.
It is resistant to sweat, but is not intended in anyway for swimming. For cleaning off sweat, we suggest using a sports equipment spray such as ‘Clear Gear.’
For cleaning off sweat or dirt, we suggest using a sports equipment spray such as ‘Clear Gear.’
Equal response though all the frequencies you are monitoring is the goal of an accurate sound system. If the producer has proof that they are working on a system that equally represents each frequency, they can trust that their decisions will not be affected by the system. The listener can reproduce the feel of the low end and have an immersive, impactful experience.
There are two things that greatly affect the M2 and M2x response, strapping and calibration. The strapping should be carefully adjusted so you can feel all the frequencies, have contact in all working positions, and feel comfortable. You will need to spend time initially listening to the calibration track, reference tones and material to adjust the strapping system to your body. Find the right balance of pressure and contact first. Notice that the top and the bottom of the unit need to be in contact with your body for full frequency response. Adjust the straps to achieve various vertical positions for maximum contact. Pressure between the unit and your body can aid in this contact, but too much will impede the transducers. Stop adjusting when you find a balance between comfort, contact, pressure and a smooth response.
We have included fabric strips on the M2 and M2x straps to accommodate wire runs. When using the M2 or M2x in a DJ booth or on stage, make sure to protect the control box from accidental disconnects and damage by using these to keep stray wire to a minimum.
The main difference is the form factor, sitting vs standing and use cases. Both products leverage the same concepts and technology to produce a smooth, accurate bass response. Even though the S2 is bigger the M2 and M2x, it has a very similar response. The main difference is that it is delivered in a slightly higher position on the body.
All SUBPAC products work with speakers by providing a tactile solution for monitoring bass frequencies. For example, when connected to a system in a DJ booth, you can feel the bass and hear the speakers at the same time. This provides an advantage for a performer who relies on being able to correctly monitor what is being output to the audience.
Music files have a maximum level of 0db, this is the highest level they can produce. Set your headphone levels to comfortably hear the loudest and the softest sounds in the music. Next, slowly add in the SUBPAC intensity until you can feel the bass in balance with what you hear in the headphones. For music that is mixed with plenty of bass, you will find this level generally between a quarter and halfway intensity. Moving past the 12 o’clock mark on the intensity knob is for tracks that have low amounts of bass or need to be enhanced. This area of the knob travel is also useful for radically boosting the amount of bass you want to feel. Using it at this level for extended periods of time may lower the life expectancy of the product depending on the source material. If you notice the control box or Pac unit getting hot, it’s time to give it a rest. This mode is not designed for full scale digital signals (0db) and you may experience amp shutdowns. If you experience this, just dial back your source material level or reduce the intensity. Feeding the M2 or M2x very little signal will also starve the SUBPAC causing you to turn it up near full intensity. For low level listeners who want to feel a lot of bass we suggest a headphone with a built in level control. This way you can feed the system plenty of level (for more bass) and then attenuate it with the inline level control.
The SUBPAC battery is rated for 8+ hours but performance will vary depending on source material and intensity levels.