Lyngdorf SDA-2400, TDAI-2170 User Manual

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How to do Bi-Amping with the TDAI-2170 and SDA-2400 amplifiers

With the introduction of the Lyngdorf SDA-2400 power amplifier, we have received many

questions about the best way to achieve optimal performance by combining it with our

integrated amplifier, the TDAI-2170.

Warning:

• These setups can only be completed with speakers constructed with separate inputs for mid­high and low frequencies.

• The inputs must be completely separated both outside and inside the speakers.

• Never connect the speaker outputs of two amplifiers in any way, as this will cause both

amplifiers to defect beyond repair.

• Keep the amplifiers off the mains power when working with speaker cables!

Class-D Amplifiers & Bi-Amping

Using Class D amplifiers in a Bi-Amping setup without enabling any filters is generally not
recommended. In a Class D amplifier an output filter turns the digital output from the amplifier into an
analog signal which powers the speaker. With Bi-Amping, the amplifier powering the bass has no
speaker-load in the high-frequencies, the energy from these frequencies will turn into heat in the
output filter. If the components of the output filter break, the speaker drivers will be damaged.

Lyngdorf amplifiers employ a sophisticated design, and we have not yet experienced a broken output
filter, but in order to protect the amplifier and speakers from potential damage, you should activate
the built-in digital crossover of the TDAI-2170 and remove the high-frequency energy (above 5,000
Hz) from the SDA-2400 driving the bass. This adjustment will have no audible effect.

Use of the Digital Crossover and Delays

Having a digital crossover in the TDAI-2170 leads many to want to use this function in their Bi­Amping setup. However, you should not apply the digital crossover to substitute for the passive
crossover network in the loudspeakers, because the crossovers inside the loudspeakers are still
active in a Bi-Amping setup.

Applying another set of crossover filters on top the speaker’s own filters is also not recommended.
With a digital connection from the TDAI-2170 to the SDA-2400, the digital signal will be processed in
the SDA-2400, and the resulting signal delay of 0.6 mSec must be compensated for in the TDAI-2170
by delaying the signal to the mid-high section.

Finally, you need to do a RoomPerfect™ calibration, and you will then enjoy the greatest
performance possible from your speakers!

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Step-By-Step Instructions

1. Remove mains power from the system.

2. Connect TDAI-2170 and SDA-2400 via digital coax signal connection.

3. Connect the TDAI-2170’s “Trigger Out” to the SDA-2400’s “Trigger In” using the cable that
came with the SDA-2400).

4. Prepare the speakers by removing the bridges between the two sets of inputs.

5. Run speaker cable between the TDAI-2170 and the “Mid-High” speaker connectors.

6. Run speaker cable between the SDA-2400 and the “Low” speaker connectors.

7. Set the input selector of the SDA-2400 to the chosen signal input.

8. Connect the TDAI-2170 and SDA-2400 to mains power.

9. Run the “Advanced Settings” -> “Guided Setup” of the TDAI-2170 and select “Speakers
with no Subs.”

a. Exit the menu before doing the RoomPerfect™ calibration (push and hold menu

button).

10. Set the menus of the TDAI-2170:

a. “Advanced Settings” -> “Outputs” -> “Digital Output” (or “Analog,” depending on

your connection to the SDA-2400). Set to “Low Pass” and set “Output Level” to -3.0
dB. This will adjust the output levels of the two amplifiers.

b. “Advanced Settings” -> “Outputs” -> “Delays”’ – Under “Digital Output” set the

“Amp. Delay” to 0,6mSec.

c. “Advanced Settings” -> “Outputs” -> “Low Pass Filter” – Set to “LR, 2

nd

Order” and

enter 5,000 Hz.

11. Perform a RoomPerfect™ calibration (“Setup” -> “RoomPerfect Setup” -> “Guided Setup”)
and follow the instructions.