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DSPXmini-FM operational manual V1.2

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While the DSPXmini-FM can help you obtain the sound that you want we must always take into account the limi-

tations presented to us by the transmission channel. The biggest problem we have is the maximum peak level 

that can be handled by that transmission channel. For FM broadcast this is +/- 7 KHz for 100% modulation.

The trade off in any audio processor is loudness vs. Quality. The mark of how good a processor is, is how loud 

the processor can be whilst maintaining sufficient quality. It is up to you where this loudness / quality trade off 

point is set. This point is also usually market and format dependent.

In the effort to squeeze as much bass and high frequency energy into the peak limited channel we must make 

compromises. Bass takes up a lot of room in the waveform and pursuit of a 'mega bass' type sound will leave 

you less room for high frequencies. When processing aggressively we usually will have to accept a certain level 

of bass distortion in making room for high frequencies or we will have to accept a certain level of high frequency 

distortion if our desire is lots of clean loud bass.

If your aim is a cleaner sound and a slight loss of loudness is not important then it is easier to get the tonal char-

acteristic you're after without distortion. Lower clipper drives will provide you with clean bass and crystal clear 

razor sharp high frequencies. The choice is yours.

More LOUDNESS

Loudness can be increased in several ways.

Multi-band AGC:

Increase the drives to the bands.

Speed up the release times, making them faster.

While it is possible to create a strange response in the multi-band AGC, it is hard to produce distortion 

because whatever gets through the AGC is dealt with by the following peak limiters. 

Multi-band Limiters: 

Slow down the peak attack times, letting more through to the clippers.

Speed up the release times of the average release time constants. 

Slow down the average attack time so that the peak time constants dominate the control signal providing 

faster control.

Increase the master limiter drive.

Increase the individual limiter drives.

Extra loudness can be obtained by working on only a single or a couple of the above suggestions. You are 

likely to run into trouble if you 'CRANK UP' all of the above settings. You are likely to generate excessive dis-

tortion in the final clippers and generate a fatiguing sound if you're not careful. Less can be more. Make small 

changes and compare against the settings of the factory presets if you find you have lost your way some 

where.

Final clippers:

Increase the final clipper drive and increase its hardness control to a higher number.

Increase composite clipper drive.

WE SUGGEST ONLY SMALL MODIFICATIONS FROM FACTORY PRESET SETTINGS IF YOU ARE 

MODIFYING LOTS OF THE PARAMETERS. IF YOU ARE ADJUSTING ONLY A COUPLE FROM THE 

ABOVE SUGGESTIONS THEN YOU PROBABLY HAVE A BIT MORE LEE-WAY. IT IS VERY EASY TO 

BECOME UNSTUCK AND LOSE YOUR WAY ONCE YOU START 'CRANKING' LOTS OF DIFFERENT 

SETTINGS.

More CLARITY

We can obtain extra clarity and quality in several ways.

Multi-band AGC:

Slow down the release times, making them slower.

Multi-band Limiters: 

Speed up the peak attack times, letting less through to the clippers.

Slow down the release times of the average release time constants. 

Содержание DSPXmini-FM

Страница 1: ...DSPXmini FM Broadcast Audio Processor Operational Manual Version 1 2 www audio processor com...

Страница 2: ...udio processing 12 Source material quality 13 DSPXmini FM placement 13 The DSPXmini FM and its processing structure 14 Processing block diagram 15 The DSPXmini FM menu system 16 The Menu structure 16...

Страница 3: ...Free inspections and maintenance repair work are expressly excluded from this warranty in particular if caused by improper handling of the product by the user This also applies to defects caused by n...

Страница 4: ...ves or other appliance including amplifiers that produce heat Power Source The appliance should be connected to a power supply only of the type described in the operating instructions or as marked on...

Страница 5: ...336 EEC electromagnetic compatibility Conformity is declared to those standards EN50081 1 EN50082 1 WARNING This equipment generates uses and can radiate radio frequency energy If not installed and us...

Страница 6: ...r was the DSPX Why DSPX Like most products the concept is conceived nameless The name DSPX came about for several reasons Firstly the BW team couldn t decide on a name we liked so the concept became D...

Страница 7: ...level control circuitry 6 x 24 bit DSP s an ethernet port a trigger port an RS232 port an LCD screen and memory devices to hold the software and firmware The Processing Architecture After input select...

Страница 8: ...NEW PASSCODE 3779 U2 ROUND FACE U3 CLASSICAL 3 A SAVE PRESET UP GO U1 BASS FACE U2 ROUND FACE U3 CLASSICAL 3 A INS DEL DONE NAME PRESET U2 MY PRESET 3 UP LOAD SAVE DSPX OUTPUT PROCESS INPUT Analogue...

Страница 9: ...PXmini FM are low and or com ing from unbalanced source you might want to set the jumpers for 12dBu operation You can check the levels going in DSPXmini FM at any time by bringing up the metering scre...

Страница 10: ...tion of the multi band AGC The range shown is 21dB to 21dB in 3dB steps There is only one meter per stereo channel and the value shown is the largest gain reduction of the left and right channels Unde...

Страница 11: ...INPUT menu Apply audio and observe the input meters 5 Select the pre emphasis setting for your region input menu 75uS for USA and 50uS for Europe 6 Navigate to the STEREO menu and adjust the MPX OUTPU...

Страница 12: ...owed by limiting and then finally peak clipping Compression Compression reduces the dynamic range of the audio waveform slowly in a manner similar to a trained operator riding the gain Compression is...

Страница 13: ...for audio storage If you must use compressed audio we advise rates of 256 Kbps and higher Linear formats are always to be preferred Compressed audio formats employ frequency masking data reduction te...

Страница 14: ...ith a choice of 4 Q s This can be thought of as a simple bass parametric Xover The DSPXmini FM employs linear phase time aligned digital FIR filtering to split the audio spectrum into 4 bands while ma...

Страница 15: ...DSPXmini FM operational manual V1 2 15 4 32 7 054 0 0 0 0 33 0 02 7 0 33 0 0 54054 08 0 4 54 08 0 0 0 4 3 08 54 308MINI 02 33 2 0...

Страница 16: ...n the softkey functions are contained in the appropriate sections of this manual Menu Structure menu input INPUT SOURCE pre emphasis menu PROCESS menu enhance peaking bass GAIN peaking bass FREQ peaki...

Страница 17: ...between 1 and 10 which corresponds to 100mS to 10S on a semi exponential scale DECAY Controls the release decay rate of the AGC the time the AGC takes to respond to a decrease of input level The DECA...

Страница 18: ...N CLIPPER HARDNESS Another distortion controlling mechanism that helps to reduce IMD in the final clipper The range is 1 to 10 with 10 producing the least distortion control A setting of 10 effectivel...

Страница 19: ...ock The options are enabled and disabled More information is available in the code lock section of this manual REMOTE SOURCE This selects the seria or the NET LAN port as the remote control method The...

Страница 20: ...peak limiter stages Because of the RMS based level detectors the multi band AGC can re equalise the sound in a more natural manner than the peak limiter stages which use peak detectors As the human e...

Страница 21: ...o illustrate things a little clearer The peak and average function can clearly be seen in the images Traditionally audio limiters have two time constants an attack the time is takes the limiter to res...

Страница 22: ...eak circuit releases to The mixer The post limiters mixer in the DSPXmini FM is not strictly a mixer but a band output level control where small EQ changes can be made Be careful when making large EQ...

Страница 23: ...range has been limited to restrict the amount of control preventing pumping and a loss of loudness which would undo what we want to use the clipper for which is gaining loudness You may not notice th...

Страница 24: ...eed up the release times making them faster While it is possible to create a strange response in the multi band AGC it is hard to produce distortion because whatever gets through the AGC is dealt with...

Страница 25: ...nd 1 and band 2 average attack time so that the peak time constant dominates the control signal providing faster control Bass clipper Increase the bass clip level WE SUGGEST ONLY SMALL MODIFICATIONS F...

Страница 26: ...tortion controlled HF clipper WE SUGGEST ONLY SMALL MODIFICATIONS FROM FACTORY PRESET SETTINGS IF YOU ARE MODIFYING LOTS OF THE PARAMETERS IF YOU ARE ADJUSTING ONLY A COUPLE FROM THE ABOVE SUGGESTIONS...

Страница 27: ...re happy with the name you press the DONE soft key to save the preset to the DSPXmini FM s memory For speed saving the current settings to the same active preset is as simple as pushing the same butto...

Страница 28: ...BASS A preset for competitive stations who want loudness and more of a signature sound with lots of bass This presets packs a maximum amount of bass while still remaining loud F6 HOT Very loud presets...

Страница 29: ...int in time so you will need to select which one of the two remote control methods you wish to use by selecting the appro priate option from the remote source parameter which is contained in the syste...

Страница 30: ...AN port to control the DSPXmini FM follow the steps below 1 Connect a cat 5 cable to the RJ45 port on the DSPXmini FM and plug this into your network hub switch A Xover cable can be used to connect di...

Страница 31: ...t of the application you have the menu preset toggle buttons These change the contents of the left hand window from the DSPXmini FM menu tree to the preset list The top right of the application contai...

Страница 32: ...efault preset Unlikely but possible Various preset operations are possible including changing the default preset saving a preset to a user preset location changing the name as well as PC file operatio...

Страница 33: ...arts Each has three parameters The left hand box contains the name of the preset that you want this daypart to switch to This box also has the ability to turn the daypart OFF by clicking down on the a...

Страница 34: ...changes you have made to the processing against the saved preset When you load a preset the buttons should be greyed out but as soon as you make any processing changes these buttons will become active...

Страница 35: ...ger pins When the trigger pins are connected to the earth return pin they will change the currently active preset to the user preset triggered by that pin If more than one pin is pulled low at the sam...

Страница 36: ...entered with the use of the rotary encoder and the GO soft key can be pressed to confirm entry and proceed If unsuccessful you will be required to try again If successful the DSPXmini FM will allow yo...

Страница 37: ...gers when the daypart start time matches the system clock You can also set the start time trigger of each daypart and set the length that the daypart shall be the time the trigger shall remain in forc...

Страница 38: ...mono from left mono from right or mono from sum Sampling Rate 32 44 1 48 88 2 or 96 kHz automatically selected Connector XLR female Pin 1 chassis ground pins 2 and 3 transformer balanced and floating...

Страница 39: ...19200 kbps Ethernet Port 10 Mbit sec on RJ45 female connector Remote Control trigger port DB9 opto isolated and floating Eight pull low inputs Other Voltage 100 240 VAC 50 60 Hz 35 VA Connector IEC De...

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