instruction manual

Below you will find important information on the connecting and placement of your new speaker.
The complete manual you can download here.

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Table of Contents
Instruction Manual GAUDER AKUSTIK

1. Connecting the amplifier
1.1 Normal stereo wiring
1.2 Bi-Wiring
1.3 Bi-Amping
1.4 The Room-Equalization device
1.5 The optimal amplifier choise

2. Room Acoustics and Loudspeaker Placement
2.1 General
2.2 Optimal Room Damping
2.3 Loudspeaker Placement
2.4 Tweaking the Acoustics of Your Room

3. General Specifications
3.1 General
3.2 Efficiency

User instructions

1. Connecting the amplifier

1.1 Normal stereo wiring

Caution! Be sure to have switched off the amplifier before connecting the speakers. Damages to your amplifier or the speakers subject to improper wiring cannot be accepted. Therefore read your amplifier manual and this manual carefully before any wiring.

Connect your amplifier or power amplifier with the loudspeaker sockets on the backside of the cabinet by a loudspeaker cable. Your Gauder Akustik-loudspeakers have single- or bi-wiring binding posts which enable you to drive the woofer (lower binding posts) and the mid/highrange drivers (upper binding posts) separately. For normal stereo connection these connectors are bridged with cables. So, it doesn’t matter if you use the upper or lower connectors except you have some favorable sound preferences. Take care to connect the right-channel speaker with the right channel of the amplifier.

Switch off the amplifier and fix your loudspeaker cable to your amplifier output sockets and the other side to the loudspeaker’s binding posts. Fix it by using banana plugs which can be simply plugged in or by unscrewing the binding post caps and pressing the uninsulated wire into the slit of the socket tack. Make sure to have the wires tightly fixed. Otherwise poor sound is most probable.

Take care of connecting the positive pole of the amplifier (normally marked red) with the positive pole of the loudspeaker connector (marked with a red ring and +-sign). A thin and diffuse sound is subject to mutually wrong connected speakers. To ease an accurate connection the wires normally are
marked somehow.

Speaker cable properties influence the sound of your HiFi-system. Depending on the combination of the system units, acoustic properties of the listening room,placement and personal taste different cables can be recommended. For more information about the right choice of cables please read the following section.

1.2 Bi-Wiring

If your Gauder-Akustik-loudspeakers are configured with Bi-Wiring connectors you can take advantage of this technique.

Just remove the bridges between the connectors by simply unscrewing the caps and fix the wires in the manner described in section 1.1. Make sure to screw the caps tightly after wiring is finished.

For the choice of the right loudspeaker wires we refer you to your local dealer.

To give you some hints we have tested a lot of different cables and cable combinations in the recent years. In principle we got the following results concerning our Gauder Akustik-loudspeakers:

Due to our philosophy the woofers only work up to maximally 180 Hz. Therefore only cables with a bigger diameter should be used for the bass drivers just to insure to transmit the required currents without any problem.

In the mid/high section wires with low inductance have always shown their benefits concerning liveness, transparency and spaciousness. There are many recommendable low- inductance cables on the market which themselves show different characters. We only use low-inductive cables by Clearwater to adjust all our speakers and these cables are also used for inner-wiring. Please ask your local dealer for a demo with this cable.

1.3 Bi-Amping

Caution! At first remove the bridges between the upper and lower connectors on your loudspeaker connector. Otherwise you damage your amplifier!

The connector of the speakers allows bi-amping that means every speaker can be driven by two or three separate amplifiers. There are some possible driving modes:
1) You possess an amplifier with no pre-out socket:
› Bi-amping is not possible. Just use the bi-wiring mode to get an improvement.

2) You posses an amplifier with a pre-out and main-in socket:
› ecial Y-connector in every pre-out socket. These Y-connectors split (double) the signals of each channel. The one side of this connector is now led back to the corresponding main-in socket of your amplifier and the other end is connected to a power amplifier. So, now the existing amplifier can drive one branch of the speaker and the additional power amplifier the other one. Just take care of buying a matching power amplifier to your amplifier or a power amplifier with adjustable output level because normally amplifiers have different sensitivities and your amplifier and the additional power amplifier may not have the equal sensitivity. In such a case the two branches of the speaker are not equally loud resulting in a strong alteration of the sound of the speakers.

3) You possess a preamp-power-amp combination
› Bi-amping is possible.
Plug in a Y-connector in each channel of the pre-amplifier output sockets. Connect the two ends to your two power amplifiers which are connected to the speaker in the above mentioned manner. Now one amp is driving the woofers and the other the mid/high range section. Also, in this mode the power amplifiers must not be bridged to mono because they act as normal stereo amplifiers. Using mono-power-amplifiers you now need 4 (6) of them.

It is recommended to use the same power amplifiers for bass and mid/high response because of their equal sensitivity which will not change the character of the speaker. But having equal sensitivity it is also possible to use two different power amplifiers.

In case you have long cables between the power amp and the speakers it is often beneficial to use the two amplifiers in bridged-mono mode enabling you to place the power amps directly to the speakers needing only short cables. Then use bi-wiring or fix the supplied bridges between the bass and mid/high connectors.

1.4 The Room-Equalization device

Our loudspeakers Cassiano and Vescova feature a device on the bottom (all others besides the Arcona-loudspeakers on the backside) with which you can adapt these loudspeakers to your room in three different settings::

- 1,5 dB: Decrease of Bass
0 dB: Linear
+ 1,5 dB: Increase of Bass

To choose between these three settings you simply have to connect the middle socket (Room EQ) with one of the three possibilities according to the connection scheme by the attached gold-plated jumpers (please have a look in your accessory box coming with the speakers).

The best way to check which position is right is listening to your favorite records and testing all three positions. This should only be done when the speakers are properly placed in the room according to section 2. For this first setup you should always use the “linear” setting.

1.5 The optimal amplifier choice

There are many well-designed electronic products on the market. Therefore we can give you no definitive recommendations especially as the products undergo a constant change and the market is always expanding.

In principle, one can state that a good amplifier should have a powerful power supply and a high damping factor. The damping factor describes the ratio between the impedance of the speaker (e.g. 8 Ohms) and the output impedance of the amplifier (e.g. 0.08 Ohms). For our example the damping factor equals 100 which is a quite reasonable value. The higher the damping factor the better is the control of the amplifier over the speaker’s own behaviour.

A well-designed power supply allows high current stability resulting in a dynamic, uncompressed reproduction. But damping factor and current stability are only two of a hundred sound relevant criteria.

Therefore we refer you to your local dealer who will present you suitable electronics for your Gauder Akustik loudspeakers.

2. Section 2

2.1 Room Acoustics and Loudspeaker Placement: General Aspects

A good loudspeaker alone doesn’t give you a perfect musical experience. Properties of the listening room, the placement of the loudspeakers and the listening position also contribute to the sound of the entire system. Acoustically well-designed living-rooms not only increase the musicality but also ease the normal living in the room. Therefore an optimally damped room not only improves the sound of the loudspeakers but also increases the quality of living. Or would you like to live in a bath-room?

The stereophonic recording and reproduction technique have for the first time enabled the listener to recognise the spatial information present at the recording session (size and depth of the room, placement of the single musicians) in his or her own living-room. But to recognise all these spatial features that are within the recordings some acoustical conditions have to be fulfilled. The acoustical properties of a room depend on its physical size, geometry and reverberation time. The reverberation time is a measure for the acoustical damping of a room. The reverberation time is defined as the time that elapses till the sound pressure level is a factor one million down of the initial sound. The sound is absorbed by the walls and obstacles which are exhibited in the sound field. The lower the reverberation time the better the damping. The degree of absorption also depends on frequency because high frequencies are more easily absorbed than low frequencies.

In the low frequency range wavelengths are in the size of the dimensions of normal rooms. The entire room resonates and standing waves appear. These room resonances are not a problem by themselves. Only if two or three of them are of equal frequency then the reverberation time and the unpleasant booming and roaring increases drastically. Even in such dramatic cases one can often reduce these problems simply by moving the speakers or changing the listening position. A well-damped room absorbs enough energy to solve this problem usually. If everything else fails then a low frequency trap has to be put into the room. The calculation and construction description of such an acoustical device is described in section 2.4.

2.2 Optimal Room Damping

It is often thought that a normal cube-shaped living-room has poor acoustical conditions. This is basically wrong. Only if the room dimensions are multiples of each other (e.g. an ideal cube) then multiple resonances occur. In a normal living-room the resonances are well divided.

Very important is the choice of the listening position. The basic room resonances have their maximum pressure at the walls. Therefore we recommend a reasonable distance from the rear wall for your listening position. Ideal would be a position of 5/8 of the depth of the room but often a distance of 30 cm away from the rear wall helps a lot.

From the so-called, „Schröder-frequency“ upwards the distances between the resonances get so small that the excitation of the room can be regarded as continuous. The „Schroeder-frequency“ depends on the size of the room and lies in the range between 180 and 250 Hz for normal-sized living-rooms. Sound waves above this value are so short that they can be damped very easily.

Now the reverberation time plays the important part for the acoustical quality. A reverberation time too high indicates that the acoustical energy cannot be absorbed sufficiently by the room resulting in bad echoes and booming effects which strongly affect the speech and music intelligibility. Music and speech then sound too bright, too harsh and unpleasant. In reverse if damping is too high and the reverberation time falls below 0.2 seconds music and voices sound dull, pressed and lifeless. Also you have to increase the power of your amplifier to get the same sound pressure level and the danger of overdriving the loudspeakers or amplifiers increases.

It was found out that a reverberation of 0.4 to 0.7 seconds is perfect for living rooms. In this range no refelection effects can be heard, no echoes appear and booming is prevented if the loudspeaker placement is optimized.

Therefore take care of reaching a mean value for the reverberation time.

As you normally don’t possess a measuring device you have to rely on your ears. This is normally a good enough tool. Just try to get an acoustical impression of your room by clapping, shouting and playing your favorite tracks. You then will easily detect all acoustical alterations done in the room. Optimal acoustical damping devices are all porous materials. Especially suited for living-rooms are: wallpapers, carpets (heavy and thick ones), curtains, decoration fabrics, pictures without glass cover, wall and ceiling covers of wood, cushions and pillows, table blankets, all kinds of furniture, books, bookshelves, chairs and tables, plants........ Plants with big leaves also increase the diffusivity of the room resulting in an even energy distribution.

And always remember: you feel better in an optimally damped room. It increases life quality!

2.3 Loudspeaker Placement

The best way to excite the room resonances is to place the loudspeakers near a wall or in a corner. Therefore try to keep some distance from the walls. 9 inches to 12 inches often improve the sound dramatically.

To cope with that problem your Gauder Akustik speakers speakers are skilfully built by precise tuning of the bassreflex system. However, if the speakers are placed too near to the rear wall spaciousness is strongly decreased. The sound image is too broad and shows no depth. Also try to position our bookshelf speakers so that the tweeter is not to far above or below the height of the listener’s ear. If loudspeakers are placed directly to the side walls just turn them in by some degree. Always remember that early reflections smear the impulse response and decrease spaciousness.

In cube-shaped rooms a placement of the loudspeakers in the direction of the longitudinal axis is recommended but in some rooms a placement turned by 90 degrees to this direction can be beneficial. You can check how good the speakers can sound in your room by aligning the stereo-axiss to the diagonal of the room. L-shaped rooms are especially troublesome because one part of the L is always excited resonantly and resonates with deep frequencies. For such rooms we always recommend to use a low frequency trap (described in the next section).

The following method enables you to set up the speakers very easily and quickly:

Take a long cable and place one speaker at your normal listening position. Then play some bass-strong music over it or use the first 26 tracks of our Gauder Akustik CD and sit on a chair in the region of your room where your speakers are intended to be placed. Move around in this zone during listening to the sine tuones which are played from the CD. Where the most precise bass response is place your loudspeakers!

2.4 Acoustic Devices

2.4.1 The Low Frequency Trap

If your room resonates strongly at frequencies below 80 Hz a low frequency trap can decrease this booming. A low frequency trap is basically a cabinet filled with some damping material and some vents in it. The air in these vents is excited at the so-called tuning frequency and excites itself resonantly the air inside of the cabinet. The air inside the cabinet transfers its motion energy to the damping material. Thus sound energy of the room is strongly absorbed, at the tuning frequency, by the trap. The problem now is to get the frequency of the room resonance and then tune the trap to this special frequency. If you have an accurate sine generator you just simply connect it to your amplifier and increase the frequency till the strong booming occurs.  

If you can’t get such a device just take the one-dimensional Rayleigh-formula described below and calculate the first three resonances in every room dimension. If two or three resonances lie within one or two Hertz the you have found the troublesome resonance. The one-dimensional Rayleigh-formula is as follows:

f = n · c / 21

with n: 1, 2 oder 3
c: 344
l: Length, width or depth of the room in metres
f: Resonance frequency in Hertz

If you have found the searched frequency the trap can be calculated. At first, fix the size of the trap keeping in mind that the bigger it is the bigger is the effect. The same is true for the number of the vents used. But by executing the following calculations you will quickly recognise that cabinets too small or too big lead to impossible lengths of the vents. So a reasonable compromise has to be looked for. As is valid for the construction of a bass-reflex loudspeaker you can’t tune small cabinets to deep frequencies and big cabinets to high frequencies.

Take the following equation for your calculations:

Lv = ( 94170 n / f 2 V ) * r 2 - 1,463 √n r

l: Length of the vent(s)
n: number of vents
r: radius of the vents
V: capacity of the cabinet
f : resonance frequence of the room

Please take care of using the radius and not the diameter of the vents and that the square root only concerns to the number of vents.
The trap should be filled with damping material from 1/3 to ½. The damping material virtually increases the capacity of the cabinet and the vents decrease it. These two reversed effects often cancel and you can take the above equation with good conscience.

The geometry and shape of the cabinet are of no interest. Recommendable are nearly cube-shaped cabinets.

As vents you can use simple plastic tubes or bass-reflex vents for loudspeakers. It is also possible to fill in the damping material through the vent holes.

The placement of your trap in your room is really decisive for the effectiveness of the trap. Normally a place at the wall or in a corner is best but you have to determine the best place by moving and hearing. As listening test you just take one CD with a boomy bass which excites the room strongly.

The best result is often achieved by placing the trap between your sofa and the wall. But remember to keep the vents free. You can also take cupboards or tables with a big foot as a trap cabinet. Or just build a trap in the right shape and use it as an additional table.

2.4.2 Reflectors and Diffusors

Many badly damped rooms exhibit long-lasting echoes which are thrown back and forth from two opposite walls. This is a very unpleasant acoustical phenomenon as it strongly decreases speech and music intelligibility. This lack of diffusivity can be omitted by „breaking“ the corners of your room with obstacles like furniture, plants, lamps or any fractal objects. It is also possible to build some corner reflectors if possible with a rounded surface and fix them in the corners. Reflectors at the side-walls should also be used if the room is too highly damped. The ear needs some information from left and right for a better speech intelligibility and localization of the acoustical sources. This lateral sound also increases the channel separation and transparency. So don’t try to damp only the side walls. The ceiling and the floor are the disturbing surfaces for music reproduction because reflections coming from up or down do not carry any stereo information and smear the impulse response. These reflections are no good. Therefore before damping the side walls try to damp ceiling and floor.

Diffusors behind the speakers bring energy to the room and increase transparency in a natural way. So do not absorb all the sound reflected by the walls behind the loudspeakers but try to reflect it diffusely!

2.4.3 Broad band absorbers

In contrast to the low-frequency region where we always try to absorb a small frequency band of some 5 Hertz bandwidth the mid range band has to be absorbed as even as possible to get a constant reverberation time of about 0.45 to 0.7 seconds for the entire range of 250 to 4000 Hertz. For this purpose many intelligent constructions exist all of which are a real problem to integrate in a cosy living-room. But this causes no real problem because normal furniture and all the things mentioned in the beginning of this section do that job as well. Just try to integrate obstacles and porous materials into your listening room and try to get an even sound field.

3. General Specifications

3.1 General

Printing all the technical specifications which are often considered to describe a loudspeaker is a weary thing. There are some international standards but often they are not obeyed or some producers have some tricky interpretations which lead to unusual high values of efficiency. All these data don’t have any relevance to the sound of the speakers. All the power handling data are expressed only for the electrical power handling. But often woofers are destroyed by mechanically overdriving them. Therefore all of the data are more than doubtful and questionable. However, if you should need these specifications please have a look at the panel on the back side of our loudspeakers.

We repeat: all technical data cannot and do not describe the sound of a loudspeaker!

A loudspeaker with a high efficiency should always be treated with care. You can get a high efficiency by directing the sound into a reduced spatial angular region (horn speakers) which leads to a bad dispersion (low lateral energy). It is a well-known thing that the ear requires a lot of lateral sound energy for recognizing space and depth of sound image and sound coloration. Good horn speakers therefore are built with spherical wave horns in the midrange. But then the efficiency comes down to normal loudspeakers. Many midrnage drivers have a good impulse but bad frequency response. To get a flat reaponse some kind of equalization is necessary which can only be done by decrease the frequency peaks to the level of the dips. This clearly results in a loss of efficiency again.

You can increase the resonace frequency of a bass-driver to increase the efficiency. But this results in a big loss of deep bass besides you take an awfully big loudspeaker or a special construction (Klipsch horn). You see all high-efficiency loudspeakers should be treated very critically and if the high efficiency turns out to be some kind of real then a flat frequency response is almost impossible. More to this topic in section 3.2

The often-heard opinion that the amp should have less power than the power handling of the speakers is completely wrong. Most of the loudspeaker damages especially with tweeters occur because of the clipping of amplifiers being too weak. Some small amplifiers even generate dc output signals when being overdriven which is very dangerous for the woofers. An amplifier with much more power will never clip or produce dc output and therefore only damages the speakers in very loud long lasting sessions.

3.2 Efficiency - Low bass - Size of Cabinet

These three loudspeaker parameters are intrinsically connected to each other and are strictly opposite. A deep bass from a small cabinet is only possible with low efficiency. A high efficiency from a small cabinet in reverse leads to a loss of the lower bass. As a constructor you have to find a reasonable compromise out of these three parameters.

Still deep in the seventies the efficiency was the most important magnitude because there were only amplifiers with comparably low power available. Today amplifier power is no longer a problem. There are many excellently sounding powerful amps on the market which are reasonable in prize.

Please never buy a HiFi device according to any technical data. Technical data have nothing to do with their sound quality. And always try to buy the loudspeakers first and then find a matching amplifier. Never do it in reverse as the loudspeaker must fit to your acoustical environment and produce a well-matched sound field in your listening room. Moreover, the differences between amplifiers are small compared to differences between loudspeakers even in the same price range.

3.3 Breaking-in

As all vibrating systems loudspeakers, too, need a certain time to reach their final state of operation. A freshly manufactured driver needs some 12-24 hours of wobbling time till it reaches its final state. Assembled into a loudspeaker this time rises drastically because of the frequency crossover which directs only a certain part of the energy to its voice-coil.

So depending upon the speaker the time for breaking-in extends to 60-250 hours. All speakers sound more powerful and homogeneous after this procedure and the low-frequency response is enhanced.

And now we wish you “Joy of Listening”!