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18S User manual

Installation

Positioning

  • 1 Subwoofer distance
  • 2 Left monitor distance
  • 3 Right monitor distance
  • 4 Listening position

The position of subwoofers in studio rooms is generally less critical compared to full-range monitors. However, best results will most likely be obtained if your 18S is placed asymmetrically between the left and right monitors or in the vicinity of one of them. If this is not practical, a subwoofer position to the side of the left or right monitor, or against a side wall can also provide good results. Try to avoid symmetry in positioning a single subwoofer with respect to the studio room boundaries.

Placing a subwoofer close to or behind the listening position, even in multi-channel installations, generally results in inferior subjective performance, especially in terms of stereo imaging.

Note

Two subwoofers used in a single installation can improve performance by maintaining low frequency stereo separation and effectively averaging the effects of low frequency room resonances (room modes). Please see installation and configuration, below for multiple subwoofers. A simple place to start is by spacing multiple subwoofers equally across the front wall, as this can help stop width modes from forming.

Moving the subwoofer closer to walls and corners will generally increase the amount of bass. Although the extra bass can be compensated for by reducing the volume level of the subwoofer relative to the rest of the system, this can result in uneven bass response at the listening position. Experiment with the position of your 18S to find one which yields the best compromise between convenience, volume and even bass response.

When using a single subwoofer, placing the subwoofer at the listening position, moving around prospective placement positions and listening/measuring to the result can often give a good indication of the performance of the subwoofer. Using a broadband signal, such as pink noise available in the RTA section of the Dynaudio Sound Meter app (available free from the Apple app store), should highlight any impact of room modes in the frequency response.

Every studio room will have “room modes”, where at specific locations and frequencies, the bass may be under or overemphasised. This effect is likely to be stronger in square and rectangular shaped rooms. Experimenting with the position of the subwoofer is likely to reap benefits in terms of minimising room modes.

Using Distance compensation

The 18S incorporates signal processing that can compensate for the time delay and volume level differences between the subwoofer and monitors resulting from their relative positions with respect to the listening position. Once you have positioned your subwoofer, measure the distances as illustrated. The measured distances should then be specified at the appropriate locations in the subwoofer configuration menu. The configuration menu is described in the Configuration section of this manual.

The 18S signal processing is able to compensate for a maximum of 5.35 m difference between subwoofer and monitor distances to the listening position.

Mains and signal connections

The 18S is fitted on its rear face with a connection and control panel carrying mains, signal and connection sockets. The panel is illustrated in Diagram 3 and its connection facilities are described in the following paragraphs.

1. Mains power socket

Connect the subwoofer to a mains power supply using the cable supplied. If multiple cables are supplied with your subwoofer, use the one appropriate for your territory.

Note

Do not switch on your subwoofer until all other connections have been made.

2. Balanced XLR input sockets (left and right)

If your monitoring hardware provides balanced outputs connect them to these sockets using high quality balanced XLR audio cables.

3. Balanced XLR output sockets (left and right)

The XLR output sockets are intended for the connection of active left and right monitors, a power amplifier driving passive monitors, or a second subwoofer.

Note

The 18S distance compensation signal processing can only function correctly if the monitors are driven via the subwoofer outputs.

Note

The 18S is equipped with an optional 80 Hz Linkwitz-Riley high pass filter on its XLR output sockets. Engaging the filter ensures that low frequency signals below 80 Hz are not passed to satellite speakers connected to the subwoofer outputs.

4. Unbalanced phono input sockets (left and right)

If your monitoring hardware provides unbalanced phono outputs connect them to these sockets using high quality phono audio cables.

Note

If your audio source provides only a mono subwoofer output it can be connected to any 18S input. In this case however the main monitors must be driven from the audio source and not via the 18S outputs.

5. Unbalanced phono output sockets (left and right)

The phono output sockets are intended for the connection of active left and right monitors, a power amplifier driving passive monitors, or a second subwoofer.

Note

The 18S distance compensation signal processing can only function correctly if the monitors are driven via the subwoofer outputs.

Note

The 18S is equipped with an optional 80 Hz Linkwitz-Riley high pass filter on its phono output sockets. Engaging the filter ensures that low frequency signals below 80 Hz are not passed to satellite speakers connected to the subwoofer outputs.

6. Trigger input

The 12 VDC trigger input enables wired remote control of subwoofer standby and operational modes in automated systems (5-12 VDC = ON). Your Dynaudio retailer or installer will be able to provide more information on the use of the 18S in automation systems.

Note

The USB socket present on the 18S connection panel is intended for fault diagnosis and firmware update only. It cannot be used for audio connection or playback. Contact your Dynaudio retailer or Dynaudio directly for more information of firmware updates.

18S Connections Schemes

Three common connection schemes are illustrated here.

Connection Scheme 1

  • Balanced (XLR) connection from preamplifier/processor to subwoofer inputs.
  • Balanced connection from subwoofer outputs to active main speakers.
  • The subwoofer should be distance-aligned as described above.

Connection Scheme 2

  • Balanced (XLR) connection from preamplifier/processor to first subwoofer inputs.
  • The first subwoofer’s input sensitivity should be set to match the preamplifier/processor outputs.
  • In order to time-align the subwoofers the latency of the second subwoofer needs to be accounted for. This is done by adding 0.86 m to the left and right distance setting in the first subwoofer. The distance used in the setting should be the distance from the listening position to the second subwoofer plus 0.86 m. The subwoofer distance should be set as the distance to the first subwoofer. See Calculation.
  • Balanced connection from first subwoofer outputs to second subwoofer inputs.
  • The second subwoofer’s input sensitivity should be set to 0 dB.
  • Balanced connection from second subwoofer’s outputs to the active main speaker’s inputs.
  • The second subwoofer should be distance-aligned as described above.
  • The subwoofers should be level-aligned using their volume setting.

Calculation

First Subwoofer Second Subwoofer
Left Speaker Distance distance to second subwoofer + 86 cm Left Speaker Distance distance to left speaker
Right Speaker Distance distance to second subwoofer + 86 cm Right Speaker Distance distance to right speaker
SUB Distance distance to first subwoofer SUB Distance distance to second subwoofer

Connection Scheme 3

  • Stereo subwoofers.
  • Left balanced (XLR) connection from preamplifier/processor to left subwoofer, left input.
  • Balanced connection from left subwoofer output to the left active main speaker.
  • The left and right speaker distances in the left subwoofer should be set the as the left speaker distance described above. The Sub Distance should be set as the left subwoofer distance.
  • Right balanced (XLR) connection from preamplifier/processor to right subwoofer, right input.
  • Balanced connection from right subwoofer output to the right active main speaker.
  • The right and left speaker distances in the right subwoofer should be set the as the right speaker distance described above. The Sub Distance should be set as the right subwoofer distance.