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Contents

System requirements

 ......................................................................................3

Installing the HELIX DSP PC-Tool Software

 ..................................................4

Connecting the PP50 DSP to the PC

 .............................................................6

Connecting the C-DSP/P-DSP to the PC

 .......................................................7

Starting the software

 .......................................................................................8

Operating controls

 ........................................................................................10

Description of the main navigation menu ..........................................................10

Channel selection

 ..........................................................................................12

Linking channels: ..............................................................................................12

Channel routing - configuring inputs and outputs

 .....................................13

Naming inputs: ..................................................................................................13

Naming outputs: ................................................................................................14

Default settings of the individual channel types: ...............................................14

Allocating inputs to outputs: ..............................................................................15

High and low-pass filter settings

 .................................................................17

Crossover frequency .........................................................................................17

Filter characteristics ..........................................................................................17

Butterworth

Bessel

Linkwitz

Chebyshev

Self-define

Slope .................................................................................................................19

Q-factor .............................................................................................................21

High-pass and low-pass filter bypass function

 ..................................................22

Adjusting the output levels

 ..........................................................................23

Adjusting the phasing and time alignment

 .................................................24

Adjusting the phase ..........................................................................................24

Adjusting the time alignment .............................................................................25

Adjusting the equalizer

 .................................................................................27

Graphic 1/3 octave equalizer ............................................................................27

PP50 DSP: Parametric filter

 .............................................................................28

P-DSP: Graphic equalizer fine adjustment function

 ..........................................29

C-DSP: Graphic equalizer fine adjustment function

 .........................................30

Measuring frequency responses

 .................................................................31

Measuring equipment .......................................................................................31

Measuring microphone

Suitable preamplifiers

Suitable measurement signals

Measurement software .....................................................................................32

Appropriate car radio settings for taking readings

Frequency response readings ..........................................................................34

Important information about the PP50 DSP ......................................................36

Summary of Contents for PP50DSP

Page 1: ...English HELIX DSP PC Tool Software Operating Instructions Version June 2011 ...

Page 2: ...tics 17 Butterworth Bessel Linkwitz Chebyshev Self define Slope 19 Q factor 21 High pass and low pass filter bypass function 22 Adjusting the output levels 23 Adjusting the phasing and time alignment 24 Adjusting the phase 24 Adjusting the time alignment 25 Adjusting the equalizer 27 Graphic 1 3 octave equalizer 27 PP50 DSP Parametric filter 28 P DSP Graphic equalizer fine adjustment function 29 C...

Page 3: ...requency responses in order to optimize the PP50 DSP to your vehicle There are now very reasonably priced systems which operate on a PC Notebook Netbook and make it affordable for everyone to achieve reliable readings The following list of components and software have been tested by us and judged to meet the operational requirements Behringer ECM8000 measuring microphone T BONE Micplug USB microph...

Page 4: ...suc cessfully installed on the computer Download the compressed zip file HELIX DSP PC Tool zip from the Audiotec Fischer website www audiotec fischer de The file can be found under the PC Tool tab This zip file contains a folder called HELIX DSP PC Tool Unpack the entire folder and save it on your hard driveImportant This folder must not be sa ved to any portable data storage media e g USB stick b...

Page 5: ...This file is located in the amplifier s first memory bank af1 If communication prob lems occur between the PP50 DSP and the interface PC Tool please install the most recent ver sion of this file The file can be found under Download under the PC Tool tab on our homepage Download the latest version of this file and install the file via a micro SD card Detailed instructions can be found under Install...

Page 6: ... PUT on the PP50 DSP Connect the HELIX Optical USB Interface USB connector to a free USB port on your PC Switch on the PP50 DSP via your car radio Please note The interface connector may only be inserted one way up Do not attempt to force the connector into the CONTROL IN PUT the wrong way up Connector to CONTROL INPUT ...

Page 7: ... Use the USB port on the P DSP Then insert the USB cable into a free port on the computer Now switch on the P DSP via the radio or the remote input or via the high level input Please note It is not possible to use the HELIX USB Interface with this processor Only use the P DSP USB port to connect to the computer ...

Page 8: ...ware has been installed on the PP50 DSP and or the C DSP P DSP instructions can be found in the user manual of the respective device In order to start the software please execute the HELIX DSP PC Tool Rev 1 XX exe file The following window will then appear on your screen Now press the Connect button If the PP50 DSP or the C DSP P DSP has been connected cor rectly the program user interface will ap...

Page 9: ...50 DSP has been connected to the PC via the HELIX USB Interface the amplifier will be in PC mode which deactivates various functions such as the under voltage detector or the automatic switching on off using High Level or Remote for example This status remains active until you close the software again correctly using the Close button It is not enough to simply break the connection between the PC a...

Page 10: ...u to select the location On confirmation the program generates a micro SD card file with the file extension ac1 This process can take up to a minute This file can then be simply installed via the micro SD card slot on any of the devices of the same type without the need for the device to be connected to the computer Please note It is then no longer possible to open and therefore amend the ac1 file...

Page 11: ...ly reduced when switching between the various setups in order to avoid any potential temporary static noise when modifying the parameters Channel routing the Configure Inputs Outputs button This button is used to switch to the channel routing overview in which you can configure any of the inputs and outputs This allows you to assign names to each of the individual channels to add up input signals ...

Page 12: ...he right and left channels should be avoided Even with the equalizer a sepa rate adjustment of channels only makes sense if sound optimization is only required for a single listening position Simply insert a tick by the channels you want to adjust simultaneously in the example above the two front channels Important information When linking two channels the adjustments made previously to one channe...

Page 13: ...nd P DSP A F to give you the best possible overview Make the transfer using the right and left mouse buttons Not used input is muted Front L Fullrange Front L Tweeter Front L Midrange Front L Woofer Front R Fullrange Front R Tweeter Front R Midrange Front R Midwoofer Rear L Fullrange Rear L Tweeter Rear L Midwoofer Rear R Fullrange Rear R Tweeter Rear R Midwoofer Center Full Center Tweeter Center ...

Page 14: ...nge Front L Tweeter 3000 Hz 12 dB Butterworth Front L Midrange 500 Hz 12 dB Butterworth 3000 Hz 12 dB Butterworth Front L Woofer 3000 Hz 12 dB Butterworth Front R Fullrange Front R Tweeter 3000 Hz 12 dB Butterworth Front R Midrange 500 Hz 12 dB Butterworth 3000 Hz 12 dB Butterworth Front R Woofer 3000 Hz 12 dB Butterworth Center Fullrange 200 Hz 12 dB Butterworth Center Tweeter 3000 Hz 12 dB Butte...

Page 15: ...at each of the output channels always equals the sum of four input signals If you only select one input signal per output the maximum possible output level is reduced by about 12 dB General information about the input output configuration You do not have to use all the P DSP inputs It is entirely possible to generate all eight output channels from only two input channels We recommend setting all u...

Page 16: ...If for example a sum signal is generated for the subwoofer from four channels front and rear the following setting is useful c If for example a front center signal is generated from the two front channels the following setting is useful d If you are only using the optical digital inputs for example the following setting would be suitable for a multiple channel configuration with a central loudspea...

Page 17: ...0 Hz and the low pass between 20 Hz and 150 Hz in increments of 1Hz C DSP It is possible to adjust the full range channels in 1 24 octave increments between 20 Hz and 20 480 Hz The high pass may be adjusted between 20 Hz and100 Hz and the low pass between 20 Hz and 150 Hz in increments of 1Hz Filter characteristics characteristics There are four different filter characteristics available for selec...

Page 18: ...pulse behavior Frequency response exhibits waviness 1 dB ripple Only recommended as a low pass for subwoofer or as a high pass as required for tweeters which are operated near to their resonance frequency Self Define Only available as a 12 dB filter with adjustable filter values Useful as a high pass filter in so called filtered bass reflex systems whereby the crossover frequency usually correspon...

Page 19: ...lter not active to a maximum of 42 dB per octave on the C DSP and a maximum of 30 dB per octave on the P DSP filter with very steep slope The effect of the slope on the frequency cha racteristics of a filter is illustrated below using the example of a 1000 Hz high and low pass with Butterworth characteristic Fig 3 Effect of slope on the high pass ...

Page 20: ... tweeter operated in a fully active system at up to 3000 Hz also requires a stee per slope 18 dB to 24 dB to avoid overloading the woofer and causing a considerable distor tion factor In most instances a high pass filter for a woofer or subwoofer is sufficiently dimensioned with 12 dB and is only necessary when small loudspeaker systems are used A lower slope steepness of just 6 dB in fully active...

Page 21: ...ing is fixed at 12 dB and there is the option of adjusting the Q factor of the high or low pass between 0 5 and 2 0 in increments of 0 1 The Q factor effect is illustrated below using the example of a high and low pass filter with a crossover frequency of 1000 Hz Fig 5 Q factor effect for the high pass Fig 6 Q factor effect for the low pass ...

Page 22: ...ction Use the bypass button to completely bridge the effect of a high or low pass filter with a single push of a button to obtain a simple acoustic comparison with and without filter Important information In fully active systems do not simply bypass the tweeter high pass filter Without any frequency crossover irreparable damage may be caused even at low volumes Bridging a low pass filter on the ot...

Page 23: ...or is a clear sign that the signal processor is overloaded which may cause a dramatic and sudden rise in the distortion factor In contrast to an analog amplifier which overloads slowly the digital amplifier stages are comparably very intolerant Digital overmodulation sounds extremely uncomfortable and may quickly damage the connected loudspeaker tweeter It is therefore preferable to set the quiete...

Page 24: ...his presents you with the following display Use the Back to DSP Menu button located in the top left hand corner to return to the previous display Adjusting the phase The phase position of each of the front and rear channels can be switched between 0 and 180 degrees Regulation of the subwoofer channel phase is particularly sensitive and may be adjusted between 0 and 360 degrees in increments of 22 ...

Page 25: ... not necessary to measure adjust the values as accurately as possible as they merely serve as initial values for the fine adjustment Now mute the rear channels and the subwoofer using the Mute function Select a piece of music which preferably consists of only a voice and no accompanying instru ments In small increments adjust the time alignment of one of the front loudspeakers until you can hear t...

Page 26: ...ed to achieve optimum stereo reproduction for one listening position in the vehicle However spatial reproduction in the other positions is usually worse with time alignment Always switch on the time alignment before you adjust the frequency response with the equali zer ...

Page 27: ... in the same 1 3 octave resolution please also refer to the chapter Measuring fre quency responses Each band of the equalizer allows a maximum boost of 6 dB and a maximum cut of 18 dB This asymmetrical design was chosen because boost levels of more than 6 dB are rarely required Any stronger narrow band frequency dips measured in the frequency response are usually due to signal cancellations caused...

Page 28: ... eliminates any dips in the frequency response A parametric filter is typically used for the narrow band resonance of a door panel for example which cannot be eliminated with the 1 3 octave equalizer The center frequency of the parametric filter may be precisely adjusted using the Hz slide control in 1 6 octave increments and for the subwoofer channel in 1 12 octave increments the corresponding va...

Page 29: ...f each channel even more accurately Therefore both the center frequency and the Q factor of each band may be adjusted with great precision To finely adjust the selected band click with the mouse on the level control of the specific band This should turn red On the right hand side in the EQ Fine Setting area you can now adjust the center frequency of the band up and down This adjustment is made in ...

Page 30: ...is makes it possible to adjust the central frequencies of each of the bands of the C DSP by increments of 1 24 octaves which allows almost any frequency to be selected as required The Q factor setting also has an extended range of possible values The adjustment ran ge lies between 0 5 and 15 whereby the individual bands may be adjusted more broadly in com parison to the P DSP This function therefo...

Page 31: ...hantom power is required for the measuring microphone to function with the PC This function can be performed by the T Bone MICPLUG USB for examp le It is simply attached to the measuring microphone and connected directly to the PC using the unfortunately very short USB cable supplied There is no need for a specific driver If the USB connecting cable is too short we recommend using an additional XL...

Page 32: ...easuring fre quency responses To simplify it we have therefore created a configuration file which performs all the necessary software settings so that you can get on with the measurements This configuration file is available on the Audiotec Fischer website under PC Tool Downloads Download the Pra xis Setup ATF ini file and save it preferably in the same directory where you previously installed the...

Page 33: ...matically load the configuration file and LOAD CONFIG will be temporarily displayed Now you need to adjust the microphone you are going to use to take the measurements Setup D A A D Dev This naturally requires that you have already connected your measuring microphone to a USB port on your PC via the preamplifier Praxis is now ready for the frequency response reading 3 4 ...

Page 34: ...d garage while you are taking the measurements so that traffic noise does not affect the readings for example Begin by measuring the front loudspeaker system i e initially mute the rear loudspeaker and any connected subwoofer e g using the HELIX DSP PC Tool Mute function Hold the measuring microphone upright and gradually turn it to a horizontal position in a semi circle between your left and righ...

Page 35: ...iminated as the ear is very sensitive to this If the graphic equalizer is insufficient for this function please use the additional parametric filter PP50 DSP or the fine adjustment function C DSP P DSP Once you have corrected the front channels mute them and activate the rear channels keep the subwoofer muted as before Now perform the measurement process as described in the same way for the rear l...

Page 36: ...onal requirements for the various loudspeaker sizes LS 6x9 or 20 cm LS high pass filter 12 dB Butterworth crossover frequency 40 Hz16 5 cm LS high pass filter 12 dB Butterworth cross over frequency 50 Hz13 cm LS high pass filter 12 dB to 18 dB Butterworth crossover frequency 70 Hz 10 cm LS high pass filter 18 dB to 24 dB Butterworth crossover frequency 80 100 Hz Now set the phase control and the o...

Page 37: ...37 Audiotec Fischer GmbH Gewerbegebiet Lake II Hünegräben 26 57392 Schmallenberg Germany Tel 49 0 2972 9788 0 Fax 49 0 2972 9788 88 E mail helix audiotec fischer com Internet www audiotec fischer com ...

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