MERIDIAN DSP750 In-Wall Digital Active Loudspeaker User Guide

DSP750 IN-WALL DIGITAL
ACTIVE LOUDSPEAKER
USER GUIDE

Important safety instructions

• Read the instructions.
• Keep these instructions.
• Follow all instructions.
• Do not use this apparatus near water.
• Clean only with a dry cloth.
• Install only in accordance with the manufacturer’s instructions.
• Refer all servicing to approved service personnel.

WARNING: TO REDUCE THE RISK OF FIRE OR ELECTRIC SHOCK, DO NOT EXPOSE THIS APPARATUS TO RAIN OR MOISTURE.

This apparatus has been designed with Class 1 construction and must be connected to a main socket outlet with a protective earthing connection (the third grounding pin).
This apparatus uses a single-pole power switch. As a result, it is not isolated from AC mains’ power when switched off at the front panel. The apparatus may be isolated from mains power either by unplugging the power connector from the rear of the unit or by unplugging the connector at the opposing end of the power cord or cable from its supply outlet. As a result, either or both of these connectors should remain accessible.

Safety warnings

WARNING!
RISK OF ELECTRIC SHOCK – DO NOT OPEN

Caution: To reduce the risk of electric shock, do not remove the cover. No user-serviceable parts inside. Refer servicing to qualified service personnel.
The lightning flash with the arrowhead symbol, within an equilateral triangle, is intended to alert the user to the presence of uninsulated “dangerous voltage” within the product’s enclosure that may be of sufficient magnitude to constitute a risk of electric shock to persons.
**** The exclamation point within an equilateral triangle is intended to alert the user to the presence of important operating and maintenance (servicing) instructions in the literature accompanying the appliance.

Climate
The equipment has been designed for use in moderate climates and in domestic situations.
Only use at an altitude not exceeding 2000m.

Safety warnings

• Do not expose the unit to dripping or splashing.
• Do not place any object filled with liquid, such as a vase, on the unit.
• Do not place naked flame sources, such as lighted candles, on the unit.

To avoid overheating

• Do not position the product in direct sunlight.
• Do not position the product near heat sources, such as a radiator.
• Leave at least 10cm around the product to ensure sufficient ventilation.

Radio interference
FCC Warning: This equipment generates and can radiate radio frequency energy and if not installed and used correctly in accordance with our instructions may cause interference to radio communications or radio and television reception. It has been type-tested and complies with the limits set out in Subpart J, Part 15 of FCC rules for a Class B computing device. These limits are intended to provide reasonable protection against such interference in- home installations.

EEC: This product has been designed and type-tested to comply with the limits set out in EN55032:2015 and EN55024:2010 + A1:2015.
IP20 EQUIPMENT

Copyright and acknowledgments

Designed and manufactured in the UK
Meridian Audio Ltd, Latham Road, Huntingdon,
Cambridgeshire, PE29 6YE, England.
Tel (01480) 445678
Email info@meridian.co.uk
Meridian Audio reserves the right to make changes and improvements to any of the products described in this document without prior notice.
Copyright © 2019 Meridian Audio Ltd.
Part no: P88468

Visit us on the Web
www.meridian-audio.com
Product registration
Register your DSP750 In-wall Digital Active Loudspeaker at: www.meridian- audio.com/register

https://l.ead.me/bbAEgZ

Introduction

The DSP750 is Meridian’s highest performing in-wall loudspeaker. Engineered using Meridian’s core principles of sound design, the DSP750 delivers high- resolution audio that is perfect for architectural installations and dedicated home theatres. Optimized for use behind a screen or stretched fabric wall coverings, the DSP750 boasts a high dynamic range and an exceptional signal- to-noise ratio enabling it to provide distortion-free audio from the quietest detail to the loudest crescendo. A beryllium tweeter with diffraction expansion technology is one of the five drive units each of which is powered by a pair of amplifiers capable of delivering over 100W into 8 Ohms. With a frequency response from 30Hz to 40kHz and an output of up to 120dB at 1m, the DSP750 delivers incredible power, fidelity, and accuracy for both music and movies.

Acoustic enclosure
The DSP750 features a sealed “double-baffle” aluminum enclosure design which minimizes unwanted resonances and colouration to ensure reliable and repeatable performance in every installation. The enclosure also acts as a heatsink with a huge thermal capacity for the built-in power amplifiers. Separate mid-range driver enclosures prevent the bass drivers from interacting with the mid-range units.

Class-M DSP engine
Phase-linear DSP crossovers with text-book performance ensure the drive units remain in phase with each other across their crossover regions. The DSP engine also provides thermal and dynamic bass protection while retaining very accurate transients, ensuring that when the loudspeaker is played at high levels – even over prolonged periods of time – it always delivers clean, detailed, and accurate sound.

Meridian DYNAMIC
amplifier design Hi-Res power amplifiers which feature feedback taken after the output inductor which lowers the output impedance to levels rivaling good Class-AB designs, for perfect cone control and maximum detail.

Centre Elevation
Meridian’s Centre Elevation technology which is based on psychoacoustic research raises the perceived image location from an under-screen loudspeaker so that it appears to come from the center of the screen.

Enhanced Bass Alignment (EBA)
Meridian’s innovative Enhanced Bass Alignment (EBA) technology time-aligns high, mid and upper bass frequencies with the low bass, resulting in audibly improved bass transients and added life and clarity.

Diffraction Expansion Technology
The innovative tweeter design delivers controlled directivity, wide dispersion, and consistent off-axis response. This means all listeners get the same experience, turning the listening room into one large “sweet spot”. As well as providing greater freedom of placement due to controlled reduction of unwanted reflections, this also makes the loudspeaker ideal for larger areas.

Construction
The DSP750 is designed to have an elegant profile, with only 102mm installation depth.
It is made up of a narrow, self-contained, all-metal enclosure with a metal mounting frame. Its purpose-built rough-in wall-box is available separately. The rough-in box is first fitted to the wall, the frame is mounted to it, and the loudspeaker enclosure is then bolted to the frame.
The rough-in box and frame can be adjusted for various wall materials and depths. The frame is designed for mounting into new-build partition and stud style walls or for retrofitting into stud or brick/stone-built walls.
A male-to-female IEC mains lead is supplied with the loudspeaker in order to connect it to the rough-in box, which is wired to power.
The paintable, perforated steel grille supplied with the loudspeaker can be fitted where required. The grille is held in place by powerful rubber-coated magnets which are attached to the aluminum extrusion that forms the front panel of the loudspeaker enclosure.

Controlling the loudspeaker
The loudspeaker can be controlled in three ways:

• In most installations, the loudspeaker will be controlled by another Meridian product within the system.
• Alternatively, the loudspeaker features an infra-red receiver which allows it to be controlled using a Meridian System Remote.
• Thirdly, the loudspeaker can be controlled using RS232 commands.

Specifications

Audio input

• 1 x Meridian SpeakerLink connector (RJ45).

Audio output

• 1 x Meridian SpeakerLink connector (RJ45).

Drivers

• Tweeter: Beryllium dome with diffraction expansion technology.
• Mid-range: 2 x 100mm.
• Bass: 2 x 160mm.

Amplifiers

• 5 pairs of Class-D amplifiers – each pair bridged, capable of delivering over 100W into 8 Ohms.

Performance

• Peak SPL: 120dB @ 1m.
• Frequency response 30Hz – 40kHz.
• Horizontal dispersion 120° @ 20Hz – 10kHz, 70° @ 18kHz (-6dB)

Front panel

• Switch selects Right, L+R, or Left or Centre.
• IR window.
• LED indicators show power status and configuration settings.

Physical

• Dimensions: 1230mm x 203mm x 102mm (48.5″ x 8.0″ x 4.0″) (H x W x D).
• Weight: 16kg (35lb).
• Grille dimensions: 1251.3mm x 222.5mm x 4mm (49.25″ x 8.73″ x 0.16″) (H x W x D).
• Excluding frame and cable feed channel.

Power

• IEC mains lead was supplied to connect the loudspeaker enclosure to the rough-in box.
• 500W max.
• This product is available factory pre-set in the following voltage options: 100V AC 50-60Hz, 110-120V AC 50-60Hz, and 220-240V AC 50-60Hz

Installing the DSP750 Loudspeaker

The loudspeaker is designed to be fitted in a Meridian wall box type RF600. If necessary, refer to the RF600 Wall Box Installation Instructions:
https://www.meridian-audio.com/rf600-installation.pdf

Contents
Each DSP750 loudspeaker is supplied with the following components:

• Mounting frame.
• Mains cable.
• M5 x 25mm clamping screws – 12 pieces.
• M5 x 10mm lock screws – 8 pieces.
• M5 x 20mm guide-in screws – 12 pieces.
• Grille.
• Grab handle.
• M3 Allen key.
• Grille extractor tools – 2 pieces

1. Prepare for installation
   • The mounting frame is fitted to the wall box prior to fitting the loudspeaker. The mounting frame is packed underneath the loudspeaker within the packing carton. The grab-handle can be used to help with lifting the loudspeaker into position. It can be found in one of the foam packing pieces within the carton.
   Remove both parts ready for installation.

2. Fit the grab handle
   • Insert the grab handle into the available holes on either side of the tweeter (see illustration below).
   • Rotate it so it locks into position.
   Note: the grab handle is not suitable to use when installing the loudspeaker horizontally.

3. Fit the mounting frame
   • Slide the mounting frame into the wall box.
   • Clamp the frame to the wall with the M5 x 25mm button-head clamping screws (12 pieces).
   Tighten just enough to clamp the frame to the wall.
   Do not overtighten as this may distort the frame.

4. Lock the frame into place
   Once the frame is tight against the wall:
   • Lock into place with M5 x 10mm button-head lock screws (8 pieces).
   • Lock tight.

5. Fit the loudspeaker
   • Using the grab handle, sit the loudspeaker on the lower edge of the wall box.
   • Plug in the RJ45 cable(s) and AC supply.
   • With the aid of the grab handle, slide the loudspeaker into position, inserting the top of the loudspeaker into the wall box first.
   • Fix with M5 x 20mm guide-in screws (12 pieces).
   • Remove the grab handle to fit the last pair of screws.
   This is no longer required.

6. Fit grille
   • Carefully hold the grille with your fingers at the top,
   • Locate the lower edge of the grille at the bottom edge of the mounting frame for alignment.
   • Lay the grille gently down onto the magnets, which will hold it in place.

Front and back panel

Connections
The following diagram gives details of the connections on the back of the loudspeaker:

loudspeaker when connecting in a daisy chain.
SpeakerLink output| The SpeakerLink input of another loudspeaker when connecting in a daisy chain.
Power| The RF600 wall box power output using the supplied plug-in mains cable.
Item| Description
---|---
Channel selector| Specifies the loudspeaker’s role in the system. See Setting up the DSP750 Loudspeaker, page 12.
RS232 socket| Allows you to configure the loudspeaker.
See RS232 via the front-panel socket, page 16.
Power switch| Controls the main supply to the loudspeaker.

Status indicators

For an explanation of the configuration status indicators see Configuring the loudspeaker using the IR eye, page 14.

Setting up the DSP750 Loudspeaker

This section explains how to set up the loudspeaker in each of the typical applications.

Using the loudspeaker on the left of the system

• Set the channel selector switch to Left or Centre.

In a multichannel system, this applies to all loudspeakers on the left-hand side of the room.

Using the loudspeaker on the right of the system

• Set the channel selector switch to Right.

In a multichannel system, this applies to all loudspeakers on the right-hand side of the room.

Using a single loudspeaker individually with a TV

• Set the channel selector switch to L+R.

If the loudspeaker is located below the display screen Centre Elevation can be used to raise the sound image up to the screen.

Choose between Off (lowest), Minimum, Medium, or Maximum (highest).
The ideal setting will depend on the layout of the loudspeaker and screen.
When the channel selector switch is set to L+R Centre Elevation can be adjusted via RS232; see RS232 control and configuration, page 16. The setting will be retained even if the loudspeaker is powered off.
Centre Elevation is only appropriate for loudspeakers located below the display screen, or the mid-height point of an acoustically transparent screen. It may be of limited benefit if the distance between the loudspeaker and the screen is small relative to the distance between the screen and the listening position.

Using the loudspeaker to play a mix of left and right audio in other situations

• Set the channel selector switch to L+R.

This will play a balanced mix of left and right audio, allowing a single loudspeaker to reproduce all the audio present in a stereo recording. It also provides a useful option for systems using multiple speakers where the listening area does not have clearly-defined left and right loudspeaker positions.

Using the loudspeaker as a center channel

• Set the channel selector switch to Left or Centre.
  If the loudspeaker is below the display screen Centre Elevation can be used to raise the sound image up to the screen.

• Choose between Off (lowest), Minimum, Medium, or Maximum (highest).

The ideal setting will depend on the layout of the loudspeaker and screen. As well as improving the sense of dialogue coming from center stage, Centre Elevation can enhance the integration of sounds that pan from left and right in a multichannel system.
When set to Left or Centre, the loudspeaker needs to have Centre mode activated in order to make Centre Elevation available. This can be done using a Meridian System Remote as described in Configuring the loudspeaker using the IR eye, page 14, or via RS232 as described in RS232 control and configuration, page 15.

In Centre mode:
If the system features a suitably-equipped Meridian controller product, Centre Elevation can be adjusted via the menu system of the controller product. Check the user guide of the controller product to see whether it supports the Centre Elevation menu and how to adjust it.
Regardless of the other equipment in the system, Centre Elevation can be adjusted via RS232. The setting will be retained even if the loudspeaker is powered off, so the optimal setting can be chosen at the time of installation as a one-off operation.
Centre Elevation is only appropriate for loudspeakers located below the display screen, or the mid-height point of an acoustically transparent screen. It may be of limited benefit if the distance between the loudspeaker and the screen is small relative to the distance between the screen and the listening position.

Configuring the loudspeaker using the IR eye

Some settings can be changed by sending commands from a Meridian System Remote (not supplied) directed at the IR eye while powering up the loudspeaker. The status of the setting is indicated by flashing indicators behind the lens of the IR eye immediately after the operation.

Centre mode
Centre mode can be toggled off and on by holding down the Left-cursor key (<) while powering up the loudspeaker.

IR eye
The IR eye on the front panel of the loudspeaker can be enabled or disabled by holding down the Next and Previous keys respectively while powering up the loudspeaker.

Next key
The white indicator flashes twice| IR eye on.
Previous key
The Blue indicator flashes twice| IR eye off (default).

Factory reset
A factory reset can be performed by holding down the Stop key while powering up the loudspeaker.

RS232 control and configuration

For the full list of RS232 commands for DSP, loudspeakers see RS232 commands, page 17. This covers non-volatile settings relating to installation options as well as standard control commands to be used by third-party control systems.

Centre mode and Centre Elevation
The commands used for Centre mode and Centre Elevation are detailed here as these features most often generate the need to use RS232 with the loudspeaker.

Centre mode
The RS232 commands related to Centre mode are as follows:

Centre.
CmOFF| Deactivates Centre mode when the channel selector switch is set to Left or Centre.
Cm| Returns the current status of Centre mode.

When the channel selector switch is set to L+R Centre mode is activated by default; otherwise, it is deactivated by default.

Centre Elevation
The RS232 commands to adjust Centre Elevation are as follows:

• By default, the loudspeaker is set to CESL, and Centre Elevation will remain set to off until it is changed by a valid command over SpeakerLink.

RS232 connection options
The loudspeaker can receive RS232 commands via the socket on its front panel or via the SpeakerLink input socket on the back of the loudspeaker. Their respective locations make the two connections suitable for particular use- cases.

RS232 via the front-panel socket
The front-panel RS232 allows you to configure the loudspeaker to suit its role in the system or perform firmware updates.
A cable suitable for connecting to the front-panel RS232 socket, terminated in a female DB9 plug, is available from authorised Meridian dealers: Meridian part number: PA10824
The socket accepts the longer version of the three-way, 3.5mm (1/8 inch) minijack plug, eg Schurter part no. 4802.1300:

The standard minijack plug commonly used on headphones and ear-buds with a shorter 14mm plug cannot be used:

RS232 via the Speaker Link input
If the loudspeaker is installed behind a projection screen or under a fabric wall-covering, the front-panel RS232 socket may be inaccessible. In this case, the SpeakerLink input cable, which also carries RS232 connections, can be used to configure the loudspeaker.

Temporarily disconnect the SpeakerLink cable from the product feeding the loudspeaker.

• Connect the RJ45 plug into an RJ45 Inline Coupler to provide an RJ45 socket.
• Connect the RJ45 socket to an RJ45 to RS232 cable.

An RJ45 to RS232 cable, terminated in a female DB9 plug, is available from authorized Meridian dealers: Meridian part number SK1622.
Where loudspeakers are daisy-chained, access to the SpeakerLink input of the downstream loudspeakers can be provided by routing all SpeakerLink feeds through RJ45 couplers located in the rack.

Connections
The two cables use the following connections for RS232:

RS232 commands

RS232 is one of several interfaces carried by the Meridian Speakerlink RJ45/Cat5 connection. The Meridian Distributor and the Meridian AC12 make this interface available on a standard RS232 connector.

Port settings
9600 Baud, 8 data bits, 1 stop bit, no parity, no flow control

Command format
RS232 commands consist of ASCII characters which are case sensitive. Some commands require parameters, so these are followed by additional characters. All commands are terminated with a carriage return. For example:
To change the volume level to 45, the command is: VN45
This will cause the loudspeaker to change its volume and respond with: Volume 45

Non-volatile configuration and reset
Some of the RS232 commands described in this document produce non-volatile (lasting) configuration changes in the DSP loudspeaker. These commands should be used carefully because they may affect the sound and operation of the loudspeaker without giving any obvious external indications.
An RS232 command is provided to reset the loudspeaker to its default configuration. For loudspeakers with IR receivers such as DSP520 and DSP640, the loudspeaker may also be reset by powering up with the stop key pressed on the MSR+ remote control. This is confirmed by three flashes from the white lights on the loudspeaker.

Loudspeaker control commands
These commands are used for everyday control of a pair of loudspeakers such as by a control system connected to the master loudspeaker through a Meridian Distributor.

Command Type| Code| Parameters| Meaning| Function| Example Response
---|---|---|---|---|---
Source Selection| CD| None, sb¹| Select source| Select source 0| CD 65
RD| None, sb¹| Select source| Select source 1| Radio 65
LP, AX, or MS| None, sb¹| Select source| Select source 2| SLS 65
TV| None, sb¹| Select source| Select source 3| TV 65
TA, T1, or IP| None, sb¹| Select source| Select source 4| iPod 65
T2 or SA| None, sb¹| Select source| Select source 5| SAT 65
CR or DC| None, sb¹| Select source| Select source 6| Disc 65
CB| None, sb¹| Select source| Select source 7| Cable 65
TX or DV| None, sb¹| Select source| Select source 8| DVD 65
V1 or the US| None, sb¹| Select source| Select source 9| USB 65
V2 or MX| None, sb¹| Select source| Select source 10| Mixer 65
LD or GA| None, sb¹| Select source| Select source 11| Game 65
SB| None| Standby| Standby| .
MU| None| Mute| Mute| Mute 65
Command Type| Code| Parameters| Meaning| Function| Example Response
---|---|---|---|---|---
Volume| V2| ##| Volume number| Go to the volume number| Volume 65
VP| None| Volume plus| Increase volume| Volume 66
VM| None| Volume minus| Decrease volume| Volume 64
Audio Effects| TN| ±##.#| Treble number| Go to treble number| Treble + 6.0
BN| ±##.#| Bass number| Go to bass number| Bass + 5.0
LN| ±##| Left number| Go to balance setting| Left  3
RN| ±##| Right number| Go to balance setting| Right  6
P+| None| Phase +| Phase +| Phase +
P–| None| Phase –| Phase –| Phase –
Display| DI| ON, OFF| Display| Light on or off| Light On

Source control commands
These commands allow control of a Meridian source connected to the master loudspeaker. No response is given on RS232.

Configuration
These commands affect only the connected loudspeaker. They configure features of the loudspeaker that would otherwise be inaccessible without a SpeakerLink capable controller.
The settings made are non-volatile (ie they remain when the loudspeaker is powered down). These settings can override commands from a SpeakerLink controller, so they should be used with caution. To restore SpeakerLink control, choose the SL parameter.

Command Type| Code| Parameters| Meaning| Example Response
---|---|---|---|---
IR receiver| IR| ON| Turns on the IR receiver’s eye| IR on
OFF| Turns off the IR receiver’s eye| IR off
Speaker position| BO| SL| Boundary EQ controlled by Speakerlink| NV Boundary Speakerlink
FR| Free-space equalization³| NV Boundary Free
WA| Wall equalization| NV Boundary Wall
SH| Shelf equalization| NV Boundary Shelf
CO| Corner equalization| NV Boundary Corner
Subwoofer| SW| SL| Subwoofer Controlled By Speakerlink| NV Subwoofer Speakerlink
OFF| Subwoofer Off| NV Subwoofer Off
1| Subwoofer Crossover¹| NV Subwoofer Sub 1
2| Subwoofer Crossover¹| NV Subwoofer Sub 2
WI| Subwoofer Wideband| NV Subwoofer Speakerlink
SG| +/–##| Subwoofer Gain⁴| NV Sub Gain 12
Command Type| Code| Parameters| Meaning| Example Response
---|---|---|---|---
Audio Effects| EA| SL, ON, OFF| Enhanced Bass Alignment (EBA)| NV EBA On
EC| SL, OFF, MIN, MED, MAX| Enhanced Boundary Control (EBC)| NV EBC Med
RH| ###| Room Height in cm for EBC⁵| NV EBA Room Height 210cm
CE| SL, OFF, MIN, MED, MAX| Centre Elevation| NV Centre Elevation Min
LO| SL, ON, OFF| Loudness| NV Loudness Speakerlink
Cm| ON, OFF| Centre mode| NV Left or Centre
6| SL, MU, MO| Music/Movie Mode⁷| NV Music Mode
Mm| None| Non-volatile| A list of the non-volatile settings
Status/Reset| NV| RS| Non-volatile Reset| Resets all non-volatile settings

Utility/diagnostic

Notes

1. When in standby, a source selection command may be followed by sb (e.g. CDs). This allows e.g. a connected Distributor to change source, but the speakers will remain on standby.
2. Available only on Meridian DSP320, DSP520, DSP640, and DSP750.
3. Free-space equalization is not available on in-wall loudspeakers.
4. The non-volatile subwoofer gain is only used when the non-volatile subwoofer setting is not SL. The range is -15 to +15 in 1dB steps.
5. The non-volatile room height is only used when the non-volatile EBC setting is not SL. The range is 150 to 400cm in 1cm steps.
6. Centre mode applies only to Meridian DSP520.2, DSP640.2 and DSP750
7. Music/Movie mode applies only to the Meridian DSW.

References

• meridian-audio.com/rf600-installation
• Meridian Audio
• Registration | Meridian Audio

Read User Manual Online (PDF format)

Read User Manual Online (PDF format)  >>

Download This Manual (PDF format)

Download this manual  >>