RoMac 10 Band Equalizer & Receive DSP Filtering

Frequently Asked Questions -- Updated 04/03/2010
Last Question to be updated click here...

  1. How do I know if my computer and sound card are compatible with the RoMac 10  Band Equalizer?

    Updated 07/30/09

Download and install the program. After installation and the software starts up without an error, normally that means your system is compatible. After proper sound card setup, if you hear yourself through the speakers with a slight delay, your system is definitely  compatible.  See Quick Start for more information. See here for information on sound cards.

If you hear a trailing echo while listening to yourself through your computer speakers or through the monitor on your radio, you are probably hearing audio from the speaker going back into the microphone. Many times an operator will then turn up the volume on the speaker to listen to the echo closer, and will exacerbate the problem. When the software is hooked up to your radio, this will not be an issue.

This point can not be stressed enough. When listening through a set of speakers, or using a boom headset, the microphone may pick up the audio and sound like an echo.

Best to use headphones, or keep the speaker volume turned down as low as possible, while testing.
Also see FAQ #16

Not all sound cards are created equal! Creative and the Turtle Beach Santa Cruz cards seem to have excellent quality.   Many inexpensive sound cards have very poor microphone preamplifiers. Built on the motherboard sound cards, sometimes pick up quite a bit of noise from the motherboard.

When installing a PCI sound card use a slot that is as far away from other cards installed in the computer, especially video cards. This will help in reducing any noise picked up from other cards installed in your computer.

If you hear low level unprocessed audio followed very shortly by processed audio, check the following:
1)  If the "No Mon" on the sound card level dialog is available, make sure that it is checked.
2)  The mute checkbox on the Microphone on the Play Side is checked.
3)  If neither control is available (grayed out)  you may have to use the software that came with your sound card. Some sound cards have very proprietary controls. Look for something along the lines of  a "Monitor" function. This need to be disabled and/o muted.

See question #17 and the Help File under "Sound Card Trouble Shooting" for help in solving interruptions in the audio stream.

The system was developed with a Creative Audigy 2Z card. It's also been tested extensively on the Turtle Beach Santa Cruz and M-Audio Delta 44 card. Although the Turtle Beach Santa Cruz is discontinued, they are still readily available on EBay for usually less than $30.00. Apparently the Santa Cruz card was used in many Dell models and are quite plentiful. The Turtle Beach Santa Cruz Card is highly recommended.  See other sound card information here...

See FAQ #20 for using the Santa Cruz Card running Windows Vista 32 bit

Some sound cards need a microphone plugged into the Mic jack and/or something in the Line In jack in order for Windows to recognize the input devices. If you get an error message about no sound card "capture device" found your sound card may require something to be plugged in.


  1. When I try to select the "Windows Mixer" from the Sound Card menu, sometimes I don't get the proper Mixer or I get a system message about a problem with my hardware.

    Only  Windows XP

    Updated 01/31/10

This problem seems only to appear when there is a pluggable USB sound device. If the USB sound card is not the "Preferred Windows" device, the operating system does not offer it to my software, even though it appears in my software as a sound card, in the select sound card dialog.

To workaround this issue, when the incorrect Window's Mixer is shown, select "Options" then "Properties", and select the desired mixer.

If you get a message indicating a "Hardware" problem, it is probably a sound card with "non-standard" controls, such as the M-Audio Delta series.

  1. I get reports of distorted audio while using the RoMac 10 Band Equalizer.

    Updated (4/3/12010)


First determine if the distortion is from overdriving something, or is it RF getting into the audio system.

The peak indicator of the equalizer should be peaking up about 1/3 to 1/2 the way up. None of the indicators should ever be yellow or red. See the help file for the equalizer to understand setting up the audio levels in your system.

If adjusting the audio levels doesn't help, it is probably RF getting into the system. A quick way to confirm this, is to reduce your power to an absolute minimum. If the distortion is gone, or much reduced, then you have RF getting into the system.

A trailing echo that is very distorted and much reduced in volume, is an indication that RF is getting into audio system. Some sound cards may manifest RF problems by the audio stream being interrupted, much like if the computer is to busy and the buffers in the software aren't set large enough.

West Mountain products (other manufacturers may do the same) have a jumper position in their microphone jumper scheme,  called "GNDTIE"  Ensure a jumper is NOT placed across the "GNDTIE" position. If the jumper is installed, this will setup a ground loop in the PTT circuit.

Some West Mountain (other manufacturers may do the same) supplied cables to connect their interface units and the radio's microphone input have a bare piece of wire on the microphone minus pin that gets pressed against the 8 pin connector case. If your connector has this wire, remove it. This practice will setup a ground loop problem between the microphone minus and the radios ground. 

The use of an isolation transformer is a necessity. The reason you need an isolation transformer is to ensure the sleeve connection from the sound card output is not grounded. Click here for sample interface circuits. Photograph of simple interface here. Another solution is a "Direct Box" that is used in the Music Industry

The sleeve is on a sound card line out is not ground. It's common to the two stereo channels. If you try connecting the sound card to the transceiver without an isolation transformer, the sleeve will be grounded at the radio.

If you have built your own interface, enclose it in a metal box, not plastic. Make sure that neither side of the input (from sound card line out) to the isolation transformer is grounded. A convenient way to address this issue, is to bring the cable directly inside the metal case (with a grommet) , with an appropriate plug on the other end.

Keep the cables going to and from the computer's sound card as short as practicable. The longer the cables are, the more they will look like "antennas" and will pick up RF quite readily.

Use quality shielded cable and shielded type connecters. Make sure all connections are tight and soldered well.

Make sure the computer case is well grounded to the stations ground. Do not use a small gauge wire, use a piece of coax braid, preferably 1/2" wide. Make it as short as practicable.

When trouble shooting, disconnect as many cables as you can. This will help in locating the problem. Sometimes disconnecting a ground, on a piece of equipment in your shack, may actually help.

You may need to place ferrite cores (Common Mode Chokes) at the Line Out, Line In , and Microphone In, at the computer end and/or on the sound card interface end.

If you are using a USB sound card, you may need chokes at one or both ends of the USB cable.

If you hear yourself all garbled in the computer speakers, while transmitting, and you are using a sound card interface, you may need to place ferrite chokes on the audio in, power cord, and the audio jumper between the speakers, all at the powered speaker end.

For larger cables, or stubborn RF, use 8 to 10 turns on a 2.4 inch type 43 or type 31 material core.  For smaller cables use 2 to 3 turns type 31 material.

Do not use unknown ferrite material. Using unknown ferrite material just won't work properly! This point can not be stressed enough. Pass up the Hamfest torrids and purchase the proper material.

Type 31 snap on beads is available from Mouser part number 623-0431167281.  Type 43 material, 2.4 inch core, Amidon part number FT-240-43. Type 31, 2.4 inch core, Amidon  part number FB-31-24001

Photographs of typical chokes here...

Do not tie your microphone ground and the PTT ground together on your radio's microphone connector. Keep them seperate. Make sure the PTT ground is ground. Some ready made cables on the market do this. There is also a misconception that you should run a piece of bare wire from your microphone ground pin, to the body of a 8 pin microphone connector. This is just asking for trouble!

For really stubborn cases of RF on the audio, you may want to remove the sound card and bypass the tip and sleeve of the Mic In, Line In, and Line Out with .01 uF capacitors. Even though today's sound cards built using surface mount components, the area around the audio jacks still should have some room to work. You will need to an ohm meter to find which connections are the ground, ring and tip.
Note: This is only a cure for RF problems that are propagated via differential mode. Which is rare if you have used isolation transformers.

Read this excellent article on RFI problems and how to solve them (pdf format)


  1. I sometimes get reports that it seems that my last syllable of a word is being clipped.
The RoMac 10 Band Equalizer has a very small delay in it. The delay is from the processing of the audio stream. The larger the audio buffers the longer the delay.

If you are keying your transmitter with a manual PTT arrangement, make sure to leave your PTT switch down just a bit longer than normal. If you are using the audio stream from the equalizer to drive the VOX in your transmitter, this will not be an issue.

Starting in version 3.1.3 there is a "PTT delay" to delay dropping the PTT signal when using a sound card interface.


  1. I get an error that only one instance of the RoMac 10 Band Equalizer can be launched. 
Make sure you didn't start a second copy of the equalizer. If it is the only instance that is running, it is probably due to lack of system resources or a sound card incompatibility. It may also be your preferred playback and recording devices in the Windows Control Panel are set to something other than your sound card.

Ensure your sound card drivers are up to date and DirectX compatible. Install DirectX 8.0 or higher.

  1. I get an error there is no sound card installed
Check the preferred sound devices in the Windows Control Panel. They should be set to your sound card, not something else such as a modem device or mapping device.
  1. License Key doesn't seem to work
Make sure you're not mixing zero's and the letter O. The "0" is a bit more elongated compared to the letter "O"
  1. When the Noise Reduction is on, the receive audio is very distorted.
Some distortion is inevitable. If there seems to be excess distortion, reduce the sound card level on the "Line (in)" on the "play side" (slider on the far right), or reduce the audio levels from the receiver.
  1. How do I set the audio levels on the sound card for receive.
Set both the "Line Record" and "Line" (Record Side & Play Side) to 1/2 way. Turn the Noise reduction on. The Peak level indicator should peak about 1/2 way while there is a signal, and fall to around 1/10 of the way up while there is a pause in the speech. Adjust the "Line Rec" and "Line" control appropriately.


  1. RigBlaster Pro Setup
Cable the RigBlaster Pro as outlined in the manual. Make sure the jumper P6 is set "Mic OUT to Computer Enabled" (See section Mic Mode Jumper - P6 in the manual). Ensure a jumper is NOT placed on P1 across the "GNDTIE" position. If the jumper is installed, this will setup a ground loop from the Mic minus to radio's ground. This is not a good practice.

Turn the RigBlaster Pro On, place Process Switch to the on position.  Your microphone is now connected to your sound card and then routed to your transceiver. When you press the PTT, the RigBlaster should be sending the proper signals on the serial line and routing the audio for for the RoMac 10 Band Equalizer & Receive filtering software.
  1. Other stations seem hear a "leading echo" at a much reduced level. Especially prevalent when using the noise gate.
If you are utilizing a sound card interface unit that routes the microphone audio, some audio is leaking through to the radio. On interfaces that utilize a jumpering scheme to accommodate different radios, double check your wiring connections. Check for a defective relay on the interface unit, and/or cable the microphone directly to the sound card. (Ground to sleeve, hot side to tip, ring no connection).
  1. When using the software there is a "burst" of noise when the software is placed into the transmit mode when in the "Rig Interface" mode or the Space Bar" mode.

    (Updated 03/13/09)
The most common cause of this that the sound card in use either does not have the capability to have a sound buffer placed on the hardware, or the operating system is not set to use hardware sound buffers. Some "on the mother board sound chip sets" will report that the sound buffer has been placed in hardware, where it really is still placed in software.

The most common solution to the problem is to go to "Control Panel -> Multimedia ->Audio->Advanced" ->Performance" and set the "Hardware Acceleration" slider to maximum on both the recording and playback devices.

If none of the above solutions work you may have to add a small delay circuit when placing the transceiver into transmit.  See the Help File under 'Serial Port Setup" and "Noise Burst - Rig Interface Mode.

  1. Heil microphones and sound cards.
Most sound cards have a positive DC voltage on the "ring" of the microphone connector, in order to work with the typical electret computer microphone. Although your microphone is monaural, use a stereo jack to connect the microphone, and leave the ring floating (not connected).

Some types of  microphones do not like to see any DC voltage on their microphone elements. If there is DC voltage on the microphone element somehow, simply put a 1 mF (non-polarized) capacitor in series with the microphone in line. Most later Heil microphones have this de-coupling capacitor installed, most older ones do not.

  1. When running under Vista or Windows 7 the program crashes when I attempt to open the Sound Card Level dialog to adjust my sound card settings.

Check to see if the software is set to run in a compatibility mode. Go to Windows help and type in "make older program work" and select item #1. Make sure the shortcut is set not to run in any compatibility mode for an earlier version of windows.

Also ensure that any sound card drivers installed are 100% Vista or Windows 7compatible.

Starting with Version 2.4.3 (build 10/30/07) software will not crash, but the "Master" sound level control will not work correctly.
  1. When running under Vista with a Delta 44 or Delta 66 sound card, sometimes the audio is very scratchy.

    Updated 6/18/08


This seems to have been corrected with Vista SP1

We are aware of the problem and not sure if its our software, or Vista or the driver from M-Audio. Usually if you go to the Select Sound Card dialog and click "Okay" to reinitialize the sound card, the audio will be clean.

This does not appear to be an issue under Windows XP.

When we have more information, it will either be fixed, or the information will be posted here.

  1. Which PTT mode does what?  (updated 2/08/08)
The "Xmit" mode is intended for users that want to just use the software for equalizing their transmit audio. (no serial port requirements)

The "Space Bar" mode is intended for uses that wish to use software to equalize their transmit audio and use the software for filtering their receive audio as well. (Serial port requirements -- Transceiver responds to  RTS signal from the software. RTS high = Transceiver go's to Transmit, RTS low = Transceiver go's to Receive)

The "Noise Gate" mode is intended for users that wish to equalize just their transmit audio and have the software key their transceiver similar to using VOX.  (Serial port requirements --- Transceiver responds to  RTS signal from the software. RTS high = Transceiver go's to Transmit, RTS low = Transceiver go's to Receive)

The "Rig Interface" mode is intended for users that wish to utilize the software for equalization of their transmit audio, and utilize the software for filtering their receive audio. (Serial Port requirements  - The Rig Sound card interface must send to the software CTS high when the transceiver is in transmit, and send CTS low when in receive.

The "Receive" mode is intended for users that want to just use the software for filtering their receive audio. (no serial port requirements)

In addition or in combination of the above serial port requirements the CW I'der requires the following.

"Key on Time" and "Click on Status". The Transceiver responds to  RTS signal from the software. RTS high = Transceiver go's to Transmit, RTS low = Transceiver go's to Receive)

"Key next Xmit" and "Key every Xmit". The Rig Sound card interface must send to the software CTS high when the transceiver is in transmit, and send CTS low when in receive and transceiver responds to the RTS signal from the software.

"Disabled" - No serial port requirements.

  1. There seems to be a "Trailing Echo" that is much reduced in volume  

If the trailing "echo" isn't distorted and you're monitoring your audio either through your radio's monitor function or through the computer speakers, it is probably audio being picked up by your microphone from the speaker. Due to the delay in the software, this will sound like an echo.

Many times the user will then turn up the volume on the speaker exacerbating the problem. Best to use headphones.

  1. Even when I set the buffers to "Large" and the sampling rate down to 22050, I still get interruptions in the audio stream when I access other software. (Updated 03/18/08)
There is software that is using up a lot of CPU cycles on your machine. Some antivirus and/or antispyware software has a tendency to us a lot of CPU cycles.

Wireless devices such as keyboards and mice are very often problematic. i.e. audio interruptions when rolling a wireless mouse, or when typing on a wireless keyboard.

Use the Task Manager in windows to observe which piece of software is using a high amount of CPU cycles when accessing other software on your system.

To start the Task Manager either use Crtl-Alt-Del or right click on the windows task bar at the bottom of the screen. To observe CPU usage select "Processes"  You may order the CPU usage by clicking on the CPU header. There will be an entry named "System Idle Process" that will show a large number. Do not concern yourself with that process.

What you are looking for is a process that shoots up suddenly when accessing other software. Either disable the culprit software or remove it from you computer.

Norton Antivirus is famous for being a memory hog as is MacAfee Antivirus.

AVG, Avast and Microsoft Security Essentials have free editions of antivirus software that have a relatively small footprint on CPU usage. RoMac Software will not be responsible for other companies software.
  1. Computer locks up after setting Priority Level to "Highest" in the select sound card dialog.(Updated 3/8/08)
We are investigating the problem. Version 2.6.2 (Build 3/8/08) detects this setting and resets it to "High". The highest setting is disabled.

You can also use Regedit to solve the problem. Navigate to the "HKEY_CURRENT_USER\Software\VB and VBA Program Settings\RoMac 10 Band Equalizer\Priority" key, and set the value to 128.
  1. Windows Vista and Windows 7 only. I still get audio interruptions even when I set the buffers to large and have the sampling rate set to 44100. (Updated 6/28/08)
Check the advanced settings for your sound card. Right click the speaker icon and select "Playback Devices". Double click the sound device and then select "Advanced". Some sound cards will need to be set to 48000 Hz, while other sound cards may need to be set 44100 Hz. The M-Audio Delta 44 card needs to be set to 44100 Hz - 2 Channel. You may need to restart the software after changing the Advanced Properties of the sound card.

Due to the way Vista and Windows 7 handles the audio stream under DirectX, a sample rate of 44100 is never recommended. This is due to the lack of support for hardware acceleration under Windows Vista. Some very fast computers may be able to use a sample rate of 44100, but most won't.
  1. Turtle Beach Sound Card under Windows Vista 32 bit (updated 05/09/08)
The Turtle Beach Santa Cruz XP/2000 drivers will operate with the software under Vista. The game port drivers will fail to install under Vista. Use this driver file originally from Turtle Beach here..

1). Install the card in an empty PCI slot.
2). The first time starting Vista, answer "No" to look for a driver for the Multimedia device.
3). Run the file sc_4193.exe
4). Let Vista install the drivers. Answer yes when you get the warning about an unsigned driver.
5). The game port driver will fail. When it fails choose "Remind Me Later"
6). Reboot and Vista will prompt you again for a driver for the game port. Answer "Don't prompt me again"

Vista's sound mixers will not see the +20 dB on the microphone (Record Device) and will be always on, but the EQ software will be able to access it, in order to turn it off.
Note: I suspect that the driver would work with Windows 7 32 bit.
  1. No sound with M-Audio Delta 44 sound card running under Windows XP  (updated 05/10/08)
Make sure under "Hardware Settings" in the M-Audio control panel "Independent" is selected under Multi Track Devices.
  1. My sound card doesn't have separate Microphone Inputs and Line In inputs.

    (updated 7/28/09)


Consider using a USB microphone. There are many quality USB microphones on the market today. Another option is to get a USB adapter for your current microphone. Shure  and Icicle makes one. Both are able to covert a standard dynamic microphone or condenser microphone for use in a USB port on your computer. Click here for more information on USB devices

Widows 2000 and Windows XP users will need to use the "Use Separate Line In" option in the select sound card dialog.

  1. My computer doesn't have a serial port.

    Updated 08/11/2010


If there is a PCI or PCIe slot available there are many good serial port cards on the market.

You may also use a USB to serial cable. All USB to Serial cables are not created equal. An excellent choice are cables from US Convertors  (USB to RS232 Premium), especially for Vista and Windows 7. The  US Convertor cable is highly recommended. Look for USB Serial convertors that have the "FTDI" chipset.

Problems manifested by inadequate USB to Serial cables can be any of the following individually or collectively, rapid keying of sound card interface, CW I'der being garbled, ID sent more than once, and random computer freezes for a few seconds.

I have some anecdotal evidence that even if you are not using the actual USB serial port that is plugged into the system, your computer still may have random slow downs/freezes when accessing another serial port 

These problems may be mitigated by increasing the serial port polling time, reducing the sound card sample rate, or increasing the buffer size.


10 Band Equalizer Product Description