Genelec HT324A Owner's Manual

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HT324A

Operating Manual

Genelec HT324A Three-Way Active Loudspeaker

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System

The GENELEC HT324A active loudspeaker

is designed for neutral sound reproduction at

high SPLs in large Home Theater rooms. The

system consists of a 160 litre loudspeaker cab-

inet and a 19” 7U rack mount ampliﬁer unit.

The cabinet contains two 305 mm (12”)

bass drivers, a 130 mm (5”) midrange, and

a 25 mm (1”) treble driver. The midrange

and treble drivers are mounted in a Genelec

Directivity Control Waveguide™ (DCW™)

which can be rotated through ±90° for either

horizontal or vertical mounting. The cabinet

low frequency -3 dB point is at 32 Hz and the

bass response extends down to 27 Hz. The

high frequency response extends up to 22 kHz

(-3 dB).

Each ampliﬁer unit contains a three-chan-

nel active crossover, driver overload protec-

tion circuits, and four separate power ampli-

ﬁers producing 2 x 400 W, 350 W and 120 W

of shor t term power in the bass, midrange,

and treble channels respectively. The crosso-

ver ﬁlter incorporates tone controls to enable

the user to accurately match the speaker to

the local acoustic environment.

number. Make sure that each ampliﬁer is con-

nected to the cabinet bear ing the same ID

number when installing multiple loudspeakers.

Make sure that the ampliﬁer is positioned

so that the loudspeaker connecting cables will

reach. Longer cable lengths can be ordered

from the manufacturer upon special request.

A space 120 mm deep should be left behind

the rear panel of the ampliﬁer unit to allow for

the cable connectors.

Check that the ampliﬁer unit is wired to the

correct mains voltage for your power supply.

The correct mains voltage for the ampliﬁer

unit is shown at the bottom of the sticker on

the rear panel of the ampliﬁer unit.

The amp lifier m ode can b e swi tched

between ON and standby modes by a remote

con trol unit connected to the respective

inputs on the ampliﬁer. Two pairs of connec-

tors are provided, 1 and 2 for a 12 V DC type

remote control, and 3 and 4 for an external

switch or relay type control. Do not connect

two remote controls to the loudspeakerat the

same time. Activate the function by turning

the "REMOTE CONTROL" dip switch on the

ampliﬁer panel to "ON".

acoustical reasons. Flush mounting improves

the bass response and efﬁciency and also

enhances the midrange transient and fre-

quency response.

The loudspeaker has its acoustical axis

midway between the midrange and treble

drivers. This axis should be used as the lis-

tening and measuring axis of the system.

(See Fig 2.1 and Fig 2.2)

The listening position should be between

2 ... 3.5 m (6½ ... 11½’) from the loudspeak-

ers. The loudspeaker should be aimed so

that the acoustical axis of the two loudspeak-

ers meet at ear height at the center of the

listening area. The loudspeakers should not

be mounted too high as this increases the

required vertical tilt of the loudspeaker and

reduces the optimum listening area.

The ceiling, side walls and especially the

rear wall should be acoustically absorbent at

low frequencies. The loudspeaker mounting

wall should be acoustically hard and there-

fore reﬂective. The mounting wall should be

angled so that the loudspeakers are correctly

aimed. Great care should be taken over how

the loudspeaker is mounted into the wall.

Unpacking

The Genelec HT324A can be transported as

a pair or as a single system. A pair is shipped

in a single box, containing two cabinets, two

ampliﬁer units, two mains connecting cables,

two LED connecting cables, two loudspeaker

connecting cables and one Allen key. (See

Fig 1)

Before installing the system, check all

items for damage and omissions. If there are

any damaged products, contact directly the

distributor and insurance agent. If there are

any missing components, contact your local

dealer or Genelec.

Installing the amplifier

The Genelec HT324A ampliﬁer electronics is

encased in a standard 19” 7U rack chassis.

The unit should be well ventilated to prevent

overheating, there must be a supply of air to

the front and sufﬁcient ventilation to dissipate

the generated heat from the space behind

the ampliﬁer unit. The maximum permissible

ambient temperature is 35° C (95° F) If the

system overheats it will stop operating until a

safe temperature is reached.

Each amplifier unit has been calibrated

at the factory with the loudspeaker cabinet it

is packed with. They also share the same ID

Loudspeaker positioning

The HT324A is designed to be ﬂush mounted

in either the vertical or horizontal conﬁgura-

tion. The DCW™ should be rotated so that

the treble and midrange drivers align verti-

cally. This ensures that optimum symmetry is

obtained.

Note that the DCW™ plate is heavy, care

must therefore be taken when removing and

replacing the DCW™. To rotate the DCW™

plate, proceed as follows:

• Place the loudspeaker in its intended

listening orientation.

• Unscrew the eight M5 ﬁxing screws on

the edges of the plate using the 4 mm

Allen key provided with the system.

• Carefully pull the plate a small distance

away from the cabinet.

• Rotate the DCW™ so that the midrange

and treble drivers are aligned vertically

(treble driver on top) and remount the

DCW™ plate reversing the procedure

above.

Flush mounting of the

loudspeaker

Although the HT324A may be used suc-

cessfully as a free standing loudspeaker,

ﬂush mounting is strongly recommended for

Note the following:

• A space 50…100mm (2..4”) wide can be

left around the loudspeaker.

• Cover the space around the

loudspeaker with a facing panel, this

should be ﬁxed to the wall. Leave a gap

of about 5..10 mm (¼..½”) between the

loudspeaker and the panel. Fill this gap

with a soft rubber gasket to allow for

possible cabinet movement.

• Ensure that the loudspeaker cables can

reach the rear of the loudspeakers.

• If a light (e.g. wooden) wall is used,

the loudspeaker cabinet should be

mounted on vibration isolators, with a

resonant frequency of around 2…8 Hz,

to prevent vibrations from being

transmitted to the wall and impairing

the low frequency performance. The

space around the cabinet should be

ﬁlled with absorbent mineral wool or

foam plastic. The walls must be well

braced.

• For a solid wall (e.g. concrete), the

loudspeaker may be directly mounted to

the wall without vibration isolators. The

space around the cabinet should be

ﬁlled with mineral wool or sand bags.

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Discontinuities in the mounting wall will cause

diffraction, which leads to inferior frequency

response and stereo imagery, so:

• Ensure that the cabinet is ﬂush with the

surface of the wall.

• If a decorative cloth frame is used to

cover the wall, make sure that the edges

adjacent to the speaker are less than

20 mm (3/4”) deep. The cloth must be

very thin Tricot or acoustically

transparent material, otherwise the high

frequency response of the system will

be adversely affected. Genelec

approved cloth grilles are available).

Recess for loudspeaker

connectors

A space at least 120 mm (4 3/4”) deep

must exist to allow for the cable connectors

behind the loudspeaker. The dimensions of

the recess should be at least 100 x 140 x 75

mm (4” x 51/2” x 3”), as shown in Fig. 6. Note

that the connectors are positioned off-center.

Therefore, if the loudspeaker is rotated for a

left and right channel, the recess will be at dif-

ferent heights on the left and right side. This

occurs when the loudspeakers are mounted

in the horizontal conﬁguration.

Connecting cable

The two connecting cables have different

types of connectors at each end, a loud-

speaker connector and an LED connector.

The loudspeaker connector is larger than the

LED connector. Insert the connectors into the

appropriate sockets found on the rear panel

of the ampliﬁer unit and the rear of the loud-

speaker.

To insert the connectors proceed as follows:

• Insert the connectors into the sockets

and turn the connectors clockwise. The

connectors lock automatically.

• The electrical connections are only

made when the connectors are fully

inserted.

To remove the connectors pull the release

lever on the connector and turn the connec-

tor counterclockwise simultaneously. The

connector can now be removed from the

socket.

Acoustical Setup

Input sensitivity adjustment

The input sensitivity of the HT324A can be

adjusted to match the output signal level of

the signal source. This is done by turning the

Speaker mounting envir onment

Flat anechoic response (factor y setting)

Free s tanding in a heavily damped room

Free s tanding in a reverberant room

Flush mounted in a hard wall

In a corner -4 dB ON -6 dB ON -2 dB ON All OFF All OFF

Table 1.Suggested starting positi ons for tone controls.

Bass Roll-Off Bass Tilt Bass Level Mid Level Treble Level

All OFF All OFF All OFF All OFF All OFF

All OFF -2 dB ON All OFF All OFF All OFF

All OFF -2 dB ON -1 dB ON All OFF All OFF

All OFF -4 dB ON -1 dB ON All OFF All OFF

‘Input sensitivity’ trimmer, which is accessed

through the front panel of the ampliﬁer unit.

However, an accurate left/right balance is

obtained when the trimmer is set to the fully

clockwise ‘cal’ position. Leaving the input sen-

sitivity trimmer in the ‘cal’ position is therefore

recommended.

To obtain the maximum sound pressure

level of 123 dB SPL, with the input sensitiv-

Control

Measuring the frequency response

The overall sound balance expe rienced

at the listening position can, to a certain

extent, be measured with steady state sig-

nals (e.g. pink noise, warble sine etc.) and

a corresponding frequency analyser. How-

ever, the results obtained are very sensitive

to the measuring methods and the equip-

ment used.

ity set to -6 dBu, a signal level of +20 dBu is

required.

Recommended Measuring Equipment

1. Microphone

Tone control adjustment

The frequen cy response o f t he system

should be adjusted to match the listening

room’s acoustic environment. This adjust-

ment is made using the tone controls, ‘BASS

TILT’, ‘BASS ROLL-OFF’, ‘BASS LEVEL’,

‘MIDRANGE LEVEL’, and ‘TREBLE LEVEL’.

These controls are accessed through the

ampliﬁer unit’s front panel. The default set-

ting of these controls is in the ‘OFF’ position,

• Always use a laboratory grade

measurement microphone.

• B&K 4134 (or similar) for far ﬁeld, 4133

or 4165 (or similar) for near ﬁeld below

8kHz.

• B&K 4004 and 4007 (or similar) up to

8kHz.

Do not use a microphone having a polar pattern

other than omnidirectional, or one not having

an accurately known frequency response.

which yields a ﬂat frequency response when

the speaker is operated in an anechoic envi-

ronment. Note that only one switch in each

control group should be in the ‘ON’ position.

The room normally boosts the low frequen-

cies compared with free ﬁeld conditions. To

get a flat room response, adjustments to

the bass tone control switches are usually

required. See table 1 for suggested starting

2. Signal Source

Use a signal source which is suitable for the

type of analyser being used. Do not use a

noise generator which is integrated into a

mixing console, since these signal genera-

tors tend to have a very coarse spectrum

content and are not intended to be used for

measurement purposes.

positions of the tone controls in four differ-

ent room types. The table shows that the

midrange and treble controls should be left in

their free ﬁeld positions, since these frequen-

cies are controlled by the speaker more than

the room. Acoustical measurements, and

3. Analyser

Any professional quality real time analyser

or tracking plotter can be used. (1/3 or 1/1

octave analysis is usually sufﬁcient for fre-

quency response balancing)

precise listening tests should be completed

by qualiﬁed personnel, to determine the opti-

mum tuning in each case.

Near ﬁeld measurement

This measurement gives an indication of the

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Loudspeaker

cabinet

Amplifier

unit

Mains

connecting

cable

Loudspeaker

connector

LED connector

Allen key

Fig 2.1 Hor izontal configuration.

Fig 1. The HT324A s ystem.

Fig 3. Speaker mou nting.

Fig 4. Speaker mou nting details.

Fig 2.2 Vertical configuration.

Fig 5. Eliminating discontinuiti es.

Fig 6. Recess for loudspeaker connect ors. (Front view)

Fig 7. Amplifier unit connec tors.

Fig 8. Speaker/LED connector

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direct sound radiation of the loudspeaker

below 1 kHz.

• Set the microphone 1 m away from the

loudspeaker on the acoustic axis. (See

Fig 2.1 and 2.2)

• Measure the frequency response of

the speaker, and adjust the tone controls

to achieve a ﬂat frequency response

below 1kHz.

Make sure that any sound reﬂecting objects

such as chairs etc. are removed from the

close proximity of the loudspeaker.

Listening position measurement

Once the near field frequency respon se

measurement has been made, the frequency

response at the listening position can be

determined by the same means. When com-

paring the results, the following items should

be noted.

1. High frequency roll-off

This is due to the following physical factors:

• Increasing room and air absorption with

higher frequencies.

• Increasing loudspeaker and microphone

directivity with increasing frequency.

2. Low frequency irregularities.

These are caused by:

• Insufﬁcient standing wave absorption in

the control room.

• Reﬂections from nearby boundaries

(Floor, ceiling, walls) interfering with

direct sound.

Incorrect vertical speaker alignment can

cause interference dips at the upper crosso-

ver frequency (around 3.2 kHz). Hence care

should be taken aiming the speaker correctly

towards the listening position. (See Fig 3.)

Overload indicators

Each loudspeaker is provided with two LED’s

marked ‘CLIP PROTECT (FAULT)’ and

‘READY’. The green ‘READY’ LED indicates

that the ampliﬁer system power is switched

on, and that the speaker is ready for use.

The red ‘CLIP PROTECT (FAULT)’ LED

indicates that the ampliﬁer system is over-

loaded or that the driver protection circuit is

activated. If the red LED lights, reduce the

signal level so that the LED stops blinking.

If this LED stays lit constantly, the ampliﬁer

thermal protection circuitry has activated.

Let the ampliﬁer cool down, and ensure that

the ampliﬁer is adequately ventilated.

Maintenance

There are no user serviceable par ts within

the ampliﬁer unit. Any maintenance of the

unit should only be undertaken by qualiﬁed

service personnel. Ensure that only fuses

of the appropriate voltage and current rat-

ings are used if a fuse has to be replaced.

REMEMBER to disconnect the power supply

by removal of the mains cable before chang-

ing a fuse. Clean the ampliﬁer unit’s air ﬁlter

every six months, or more frequently in dusty

environments. The air ﬁlter is located behind

the grille, found to the left of the front panel.

The air ﬁlter can be cleaned with a vacuum

cleaner without removing the grille.

Safety considerations

Although the HT324A has been designed in

accordance with international safety stand-

ards, to ensure safe operation and to main-

tain the instrument under safe operating con-

ditions, the following warnings and cautions

should be observed:

• Servicing and adjustment must only

be performed by qualiﬁed service

personnel. The loudspeaker or the

ampliﬁer must not be opened.

• The ampliﬁer must only be connected

to mains socket outlet with a protective

earthing connection.

• Do not use the ampliﬁer with

an unearthed mains cable as this may

compromise electrical safety.

• Do not expose the loudspeaker or the

ampliﬁer to water or moisture. Do not

place any objects ﬁlled with liquid, such

as vases, on the loudspeaker or near it.

• Do not place naked ﬂame sources like

lighted candles on or near the

loudspeaker or the ampliﬁer.

• This loudspeaker is capable of

producing sound pressure levels

in excess of 85 dB, which may cause

permanent hearing damage.

• Proper ventilation of the ampliﬁer is

necessary to maintain sufﬁcient cooling.

Ensure that air ﬂows freely into the

openings on the ampliﬁer front panel

and that the space behind the ampliﬁer

is sufﬁciently ventilated to dissipate the

generated heat.

• Note that the ampliﬁer is not completely

disconnected from the AC mains service

unless the mains power cord is removed

from the ampliﬁer or the mains outlet.

Guarantee

This product is guaranteed for a period of one

year against faults in materials or workman-

ship. Refer to supplier for full sales and guar-

antee terms.

EC Declaration of Conformity

This is to certify that Genelec HT324A loud-

speaker conforms to the following standards:

Safety:

EN 60065 / IEC 60065:1998 7th Edition

EMC:

EN 55013: (2001)

EN 55020: (1994), A11: (1996), A12: (1999),

A13: (1999), A14: (1999)

EN 61000-3-2 (2000)

EN 61000-3-3 (1995)

The product herewith complies with the

requirements of The Low Voltage Directive

73/23/EEC, EMC Directive 89/336/EEC and

93/68/EEC

Signed:

Ilpo Martikainen

Position: Chairman of Board

Date: 16-January-2006

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HT324A Operating Manual

Figure 9: The above cur ves illustrate the effect of the 'bass tilt', 'bass rolloff' and 'bass',' mid' and 'treble' level controls on the free field response, measured at 2 m

SYSTEM SPECIFICATIONS

Lower cut-off frequency, -3 dB: <32 Hz Upper cut-off frequency, -3 dB: Free ﬁeld frequency response of system: 33 Hz - 20 kHz (± 2.5 dB)

Maximum short term sine wave acoustic output on axis in half space, averaged from 100 Hz to 3 kHz @ 1 m Maximum long term RMS acoustic output in same conditions with IEC-weighted noise (limited by driver unit protection circuit)@ 1 m: ≥118 dB SPL Maximum peak acoustic output per pair @ 2 m from the engineer with music material: >125 dB

Self generated noise level in free ﬁeld @ 2 m on axis: Harmonic distortion at 100 dB SPL @ 1m on axis: Freq: 50...200 Hz <1%

200...10kHz <0.5% Drivers: Bass 2 x 305 mm (15") cone Mid 1 x 130 mm (5") cone Treble 1 x 25 mm (1") metal dome

Weight: Speaker 73 kg (161 lb) Ampliﬁer 30 kg (66 lb)

Speaker dimensions (Horizontal mounting): Height 700 mm (27 Width 890 mm (35")

>20 kHz

>123 dB SPL

≤15 dB(A)

/16")

CROSSOVER SECTION

Bass ampliﬁer output power with an 8 Ohm load: Short term 2 x 400 W Mid ampliﬁer output power with a 8 Ohm load: Short term 350 W Treble ampliﬁer output power with an 8 Ohm load: Short term 120 W Long term output power is limited by driver unit protection circuitry.

Slew rate: 80 V/µs Ampliﬁer system distortion at nominal output: THD SMPTE-IM CCIF-IM DIM 100

Signal to Noise ratio, referred to full output: Bass Mid Treble

Mains voltage: 100/200 or 115/230V Voltage operating range at 230V setting: 207 - 244 V (-10/+6 %) 115V setting: 104 - 122 V (-10/+6 %) Power consumption: Idle 70 W Full output 1000 W

Depth 383 mm (15")* Ampliﬁer dimensions: Height 310 mm (12 Width 483 mm (19") Depth 250 mm (9

/16")

/16")*

Figure 10: The upper curve group shows th e horizontal directivity characteristics of the HT324A in its hor izontal configuration measured at 2m. The lower curve is a 1/6 octave power respon se measurement, derived from 144 di rectivity measurem ents.

AMPLIFIER SECTION

Input connector: XLR female pin 1 gnd pin 2 + pin 3 -

<0.05% <0.05% <0.05% <0.05%

<100 dB <100 dB <100 dB

Input impedance: 10 kOhm balanced

Input level for 100 dB SPL output @ 1m: variable from +6 to -6 dBu

Input level for maximum short term output of 126 dB SPL @ 1m: variable from +32 to +20 dBu

Subsonic ﬁlter below 25 Hz : 18 dB/octave Ultrasonic ﬁlter above 22 kHz: 12 dB/octave

Crossover frequencies: Bass/Mid 400 Hz Mid/Treble 3.2 kHz

Crossover acoustical slopes: >24 dB/octave

Level control operating range in 1 dB steps: Bass from 0 to -6 dB & MUTE Mid from 0 to -6 dB & MUTE Treble from 0 to -6 dB & MUTE

Bass roll-off control in 2 dB steps: from 0 to -8 dB @ 32 Hz

Bass tilt control operating range in 2 dB steps: from 0 to -8 dB @ 50 Hz

The 'CAL' position is with all tone controls set to 'off' and input sensitivity control to maximum and corresponds to a maximally ﬂat free ﬁeld response.

Genelec Docu ment D0072R001 Copyrig ht Genelec Oy 1.2006. All data subject to change without prior notic e

Inter national e nquiries:

Genele c, Olvitie 5

FIN-74 100, Iisal mi, Finlan d

Phone +358 17 83 881

Fax +358 17 812 267

Email genele c@genelec.com

In the U.S. please c ontact:

Genele c, Inc., 7 Tech C ircle

Natick, MA 01760 , USA

Phone +1 508 652 0900

Fax +1 508 652 0 909

Email genele c.usa@genelec.com

In Chi na please contact:

Genele c China Re presentati ve Office

Soho N ew Town, 88 Jiangu o Road

D-1504 , Chaoyang D istrict

Beijin g 100022, China

Phone +86 10 858 0 2180 Fax +86 10 85 80 2181

Email genelec.china@genelec.com

www.genelec.com

In Sweden ple ase contact

Genelec Sveri ge

Ellipsvägen 10 B

P.O. Box 5521, S- 141 05 Huddinge

Phone +46 8 449 5220

Fax +46 8 708 70 71

Email info@gen elec.com