Set Up for Audiophile Augmentation – Single Sub-Bass System
An MJ is not a traditional subwoofer, but a true Sub-Bass System. An MJ Subwoofer is designed to augment the performance of “full range” speakers in order to provide an extended response in the lower octaves. If you are not an existing MJ Sub-Bass system owner then you will need to disregard much of what you thought was the correct method of integration into a stereo or home cinema system.
Set-up and positioning of MJ Sub-Bass Systems differ from conventional subwoofers. An MJ does not need to take advantage of corner room loading to provide deep pressurisation as traditional subwoofers do. Initial set-up should take no more than ten to fifteen minutes to accomplish once connected.
The High-Level Way for connection
It is helpful to know that you will almost always connect an MJ Sub-Bass system to the input on the rear panel labeled “HIGH-LEVEL INPUT” to achieve Audiophile Augmentation. This applies to systems where there is no alternative method of output from the pre-amplifier or where you are using an integrated amplifier without subwoofer pre-out. This connection is best made using our specially developed 4-meter High-Level Lead, the Gold plated spades of which connect to the speaker output terminals of the power amplifier. The connection at the MJ is accomplished using the terminated Neutrik Speakon plug. The purpose of connecting to the speaker output terminals is one of the unique secrets of MJ’s success, dating back to 1998. By connecting to the high-level input on the MJ from the amplifier output terminals, you allow the MJ to extract the audio frequency information being sent to the main speakers. This is so important with regard to accurate integration because the timing and tonal energy replicate that of the main signal information from the amplifier. Connection direct to the terminals on the speaker can also be made and in the case of a multiple MJ subwoofer setup, this is the preferred method for connection. MJ Subwoofers do not come as standard with this very special High-Level BASS – Inter-Connect lead so ask your dealer for more information and take a look at the BASS– Inter-Connect page for more information. There are some topology designs of integrated amplifiers and monoblock power amplifier that are not safe to connect by High-Level without the use of an interface or special wiring considerations. if in doubt talk to your dealer or email techical@mjacoustics.co.uk. We will be pleased to assist you.
Unlike standard subwoofers which require the use of corner loading, the MJ does not have to be placed in one of the corners behind the speakers. An MJ Sub-Bass system is very efficient and audiophile augmentation can be achieved by almost any placement. In extreme cases where perhaps a room is very large and the Sub-Bass system chosen is smaller than desired, corner loading can be considered. You have, at your disposal, a true LOW bass pressurisation instrument with an MJ.
High-level connection, using the enclosed cable with the Neutrik Speakon connector can be made without affecting the performance of the amplifier because the MJ’s input circuit impedance is 100,000 ohms, in effect not producing any additional demand on the rest of your system. Your power amplifier will not know the MJ is attached. When connecting to a home cinema system where a .1/LFE channel output is present, connect a single phono cable between the sub-output of the Processor/AVReceiver and the .1/LFE input RCA on the MJ.
Positioning: Don’t be fooled into believing there is an optimal position. This is only specified by some of our competitors because their subwoofers need additional corner loading to enhance their output. The optimal position for an MJ is where ever you want to place it. When you have a cabinet that has been manufactured as a piece of furniture why hide it? In the case of Reference Series and especially the Master-Class series with their Glass tops and polished front display, you may want it on show in much the same way you want your main speakers on show. Corner positioning is also fine if this is your desire. This position provides, in some cases, an excess of 6dB of refractive amplification. Placement in any location allows for linear non-directional bass wave formation because we downward fire and upward fire the bass sound waves from an MJ Sub-Bass system.
The Process: To begin the set-up process, choose a piece of music that has a repetitive bass riff that is low in frequency. It should be a clip that you are familiar with so that you can more readily interpret any changes in dynamics as the setup procedure progresses.
This track is for the set-up process and should be played at the highest reasonable level expected for system playback. Working with a partner, one in the listening position and one at the MJ subwoofer, manipulating the controls, is the most effective and efficient way to set up the MJ that does not have the “Smart Remote” App feature. Ignoring all other music in the track, listen for the bass and its effect on the listening room.
Phase: Once in the desired position, adjustment for the phase must be considered. (see more details on the setting up of Phase) This may be the single most critical step really is quite simple. it is often considered to complicated and therefore overlooked. The correct phase setting is the loudest or fullest output from the listening position.
1. While playing your chosen music with true low bass, adjust the crossover to a point just above the speaker published -3db specification. This will be the point where the MJ and the speaker are producing the same frequencies. (for “Damp 2nd & 3rd Gen” enabled products this is very accurate because the exact frequency can be dialled-in)
2. Turn the HI/LO Gain level control up so that both the MJ and speakers are roughly equal in volume but the MJ output is clearly noticeable.
3. Using the phase setting adjust from “0” to “180” phase steps. Whichever setting is loudest or fullest is the correct setting. We are looking for bass addition and not canceling it at this point in the procedure.
If you have a smaller than desired Sub-Bass system then the benefits of corner loading acoustic refraction amplification can be considered at this point.
4. With the MJ fully into the corner, continue to play the music, pull the MJ from the corner on the diagonal, equidistant from both side and rear wall. At a particular point (this could be only a matter centimetres, in rare cases 1/2m or more) the MJ will audibly sound lower in its extension, it may also appear louder. This is considered the correct position from the corner for the MJ enabling maximum benefit from the corner loading increased output.
Orientation: With downward-firing drivers, we can enjoy a fully non-directional flow of bass detail so the orientation of the cabinet is a matter of pleasurable aesthetics only.
Crossover and Gain Level Settings:
1. To determine the crossover point, take the volume of the MJ (using the HI/LO Gain level control) all the way down -99 on the display, and put the crossover to 25 Hz.
2. At this point, bring the MJ’s volume back up slowly to the point where you have achieved a subtle balance, i.e. the point at which you can hear the MJ even with the main speakers playing.
3. Raise the crossover point up to the speakers published -3db specification. For the initial setup, this is the correct crossover point. Once this stage has been reached, subtle changes to volume and crossover can be made to allow for a bass driver running in period and provide seamless integration. Initial set-up is complete for Audiophile only use.
Set Up for Home Cinema Applications using .1/LFE with Audiophile Augmentation
If your system is being configured for both Audiophile and Home theatre requirements first follow the procedure above before reading on.
For all multi-channel encoded material whether that be Dolby® Digital AC-3 or other 5.1 Theatre source material, once the standard set-up for two-channel outlined above is complete, the LFE output from the processor or AVReceiver should be connected to the .1/LFE INPUT and appropriate volume adjustments made using the .1/LFE level control. For this configuration, you must make sure you have set the processor or AVReceivers speaker configuration to the “large” or “full-range” setting for the left and right speakers in order for the MJ to receive the bass signal via the high-level cable. In this configuration, the MJ provides support for both the left and right speakers for two-channel listening and support for the .1/LFE when movies are playing with an encoded LFE channel. The effect of this set-up provides for increased dynamics with no bloated or woolly bass and a greater feel from the special audio effects encoded within the movie source material. The crossover setting for the .1/LFE should be set to 80Hz which is the default setting for most processor and AVReceivers LFE output. Volume level should be set to about halfway or -40db on the MJ display. Using the setup procedure recommended for the AVReceiver the correct output level can be automatically accomplished. Setup is now fully complete.
For those of you that want to further enhance your movie experience then the following procedures will take your audio experience with multi-channel source material to the next level.
MJ Multi-Sub-Bass Reference configuration
While slightly more complicated than the basic MJ setup for Home Cinema, use of three MJ subwoofers produces a number of benefits and is the most cost-effective method of achieving professional Dolby® 5.1 & DTS® standard bass performance. MJ Multi-Sub-Bass Reference configuration produces a true full-range performance from the primary zones of reproduction in theatre sound resulting in a far more natural and immersive experience than any single sub can produce. These zones can be defined as follows:
Front Left and Right Main Speakers with .1/LFE. Centre Channel speaker and of course the Rear Left and Right effects channels that make up the standard Dolby® 5.1 & DTS® configuration.
It can be argued that where ever there is a speaker, then the bass should be underpinned using a subwoofer. True, but the use of 3 MJ Sub-Bass Systems gets your setup to a point where the main sound zones are augmented for the best sound-for-pound from your investment.
This brings us on to the joy of MJ Smart Remote. This fantastic remote control feature enables connection of all MJ Sub-Bass Systems to one remote control and for that single point of control to communicate bi-directionally with each subwoofer at the same time. This aids in the setup like no other subwoofer can in the world. using the built-in RTA (Real Time Analyser) audio frequency response changes are presented visually as well and aural. Settings can be seen directly in front of you and the simultaneous adjustment changes made to all subwoofers in a group can deliver an instant aural change so as to reach the perfect integration with ease. Once you have used this system of remote control you will wonder how you managed without it.
1. The main Left and Right speakers should be connected to the primary MJ using MJ Set Up for Audiophile Augmentation connection procedure. This Sub-Bass system forms the foundation of your theatre system’s performance and so should be perfectly matched to one’s main speakers. The .1/LFE on this primary Sub-Bass system should have also been setup as detailed above. This is your primary zone and will already be configured. If not then complete this first and continue from here.
2. In the rear of the room (ideally opposite the primary sub-bass), connect the 2nd MJ to the rear effect speakers using an MJ High-Level lead. The purpose of the rear channel MJ is to ensure proper front-to-rear balance and weight; with conventional setups nearly all the power and weight in a theatre comes from the front and it produces unnatural weighing as well as peaks and troughs. By placing a rear MJ opposite, bass emanates from multi-points smoothing overall in-room response and further increasing dynamics of your soundstage. This sub-bass need not be a duplicate of your primary MJ; instead, it should be chosen based on your surround speakers.
3. Connect the third MJ to the centre channel using only the HIGH-LEVEL connection. This may be easily accomplished by connecting directly to the connection terminals on the rear of the centre channel speaker. To do so, lay the spades of the red and yellow leads on top of each other and connect to the positive terminal, then connect the remaining black lead to the negative (black) terminal on the rear of the speaker. The purpose of the third “centre ” MJ is to ensure the centre channel can keep up with the scale, weight and dynamics the main system now has. The location can be anywhere from the opposite side of the front wall to somewhere in the middle of the front wall, listen for best integration with the centre channel speaker. Some people prefer to use the MJ as a centre channel speaker stand – very useful if your system has a projection screen and is in a larger room. Again, this sub-bass need not be an exact duplicate of the primary MJ but should be chosen for its acoustic ability to mate seamlessly with your centre channel.
First, carefully set-up and dial-in the primary MJ Sub-Bass, then move to the rear MJ Sub-Bass and balance this against the primary MJ Sub-Bass. Care must be taken to ensure phase is identical on both MJ sub-basses. Finally, dial-in the settings for the centre channel sub.
You can use the group power off feature within Smart remote to turn off each sub-bass system in turn to dial-in the next. When you are done simply hit the all on button on Smart Remote and they all come back on. it’s so easy!
For non Smart Remote enabled sub-bass systems (in general those manufactured before August 2017) to make this easier, once the primary MJ has been dialled in, unplug it using the Speakon connection and dial-in the rear, followed by the centre channel MJ.
A note on Running In
Care taken while running in will result in many years of reliable and enjoyable bass augmentation. Both the electronics and the drive unit will benefit from an extended initial period of carefully controlled use. Possible damage may be sustained by running the volume level at too high a setting over an extended period. if you take a little care over this initial period, about 100 hours of actual use, a longer life will be assured.
A note on connection with Mono Block Amplifiers or Stereo Integrated Amplifiers
1. When using monoblock amplifiers with High-Level lead connection. Join Red and Yellow leads together and attach the joined wire to + on the amplifier speaker terminal. Attach the Black lead to – on the amplifier speaker terminal.
Repeat for the second monoblock amplifier channel.
2. When using a stereo amplifier with two MJ Sub-Bass Systems. Join Red and Yellow leads together and attach the resulting joined wires (spades) to + on the amplifier speaker terminal say Left channel then attach the Black lead to – on the matching amplifier speaker terminal.
Repeat for the second channel with the second MJ Sub-Bass system.
Balanced differential design amplifiers
When using balanced differential design amplifiers, it is critical that the user follows the instruction for differential design connection. This requires that the user attaches ground (Black wire) to CHASSIS GROUND and NOT to speaker ground.
Remember that each channel must have its settings calibrated individually. After connecting dial in the Left channel first (with right channel not active). Once you have obtained the best settings for the Left channel, disconnect the Left channel and plug in the Right channel. Repeat the set-up process using ONLY the Right channel.
Please also make sure that the Phase setting MUST be the same for both channels or bass cancellation will occur.
Do NOT be concerned if the gain and crossover settings end up being quite different between the channels. Rooms are remarkably different from side-to-side and one should expect quite different settings to result from a properly dialled-in set-up due to room peaks and troughs, known as nodes that occur on one side, but not the other. it is merely confirmation that a two sub-bass system is a worthwhile investment when striving for the purest of HiFi reproduction.
Finally: Having calibrated each sub-bass individually they can be both connected. This will result in too much bass output. Reduce the gain carefully in 1dB steps using the Smart Remote group feature for simultaneously decreasing the gains until the system is balanced. If your subwoofers are not Smart remote enabled then make changes to each gain singularly until the desired result is achieved.
