User manual
Table Of Contents
- Important Information
 - 1 Product Overview
 - 2 Installation and Setup
 - 3 Acoustic Measurement
 - 4 Filter Design
 - 5 Using the DDRC-88A audio processor
 - 6 Optimizing gain structure
 - 7 Additional Information
 

  PRELIMINARY AND SUBJECT TO CHANGE  
miniDSP Ltd, Hong Kong / www.minidsp.com / Features and specifications subject to change without prior notice  32 
High-frequency “tilt” 
  The target curve is the desired measured response of loudspeakers in a room, In contrast to 
measurements made of a loudspeaker during its design under anechoic (measured in free space) 
conditions. While high-quality loudspeakers are usually designed for a flat on-axis anechoic 
response, these same speakers when placed into a listening room will tend to have a downward-
sloping or “tilting” response at high frequencies, due to the effects of limited dispersion at high 
frequencies and greater acoustic absorption. 
  A completely flat in-room response is therefore usually not desirable and will tend to sound thin 
or bright. Start with a target curve that follows the natural behavior of your speakers in your 
room, and then experiment with greater or lesser degrees of tilt in the treble region to obtain 
the most natural timbral balance. 
Low-frequency adjustment 
  A completely flat response at low frequencies, with complete elimination of peaks due to room 
modes, may sound light in the bass. Often, a slight increase in the target curve below 100 Hz will 
give a more balanced sound, yet without introducing audible irregularities in bass response. 
Magnitude response dips 
  In some cases, it may be helpful to adjust the target curve to follow dips in the magnitude 
response. This can occur where, for example, the listening area is very close to the speakers and 
the measurements exhibit a dip caused by the vertical response of the speakers themselves. In 
such a case, adjusting the magnitude response to follow the dip will avoid making the speakers 
sound worse elsewhere in the room. (You may also wish to try a different set of measurement 
locations.) 
Unlinking channels 
  Usually, the corresponding left and right channels (front left and right, surround left and right, 
and rear left and right) should remain linked for target curve adjustment, to ensure that both 
sides produce the same response across the listening area. In certain unusual circumstances, 
such as where the magnitude response dip discussed in the previous point shows up on only one 
side, you can try unlinking channels and making separate adjustments. 
4.2.4  Saving and loading target curves 
To allow you to experiment with different target curves, you can save a target curve to a file and reload it at a 
later time. The default directory for these is C:\Users\[User]\AppData\Roaming\Dirac\OEM\MiniDSP\Targets, 
but you can store them in any location in your file system. To save the target curve of the currently displayed 
channel or group of channels, click on the Save Target button. 
To load a target curve, click on Load Target. The currently displayed channel or group of channels will have its 
target curve updated. (Loading a target will erase the current target curve, so be sure to save it first if needed.) 










