10 Band Graphic Equalizer
by Atlanta Signal Processors, Inc.

Software Overview

This 10 Band Stereo Graphic Equalizer was implemented on a TMS320C3x DSP, and is constructed from 
10 parallel IIR biquad filters with identical Q factors and center frequencies spaced at octave 
intervals across the audio range. The gain of each filter is variable, providing cut or boost 
across the entire spectrum. In addition, the resulting equalized audio spectrum is displayed real 
time. This is a stereo implementation, with pan and master gain control, with the option to operate 
in mono available to the user.
A 10 band stereo graphic equalizer is often used in applications that require enhancement to 
sampled audio data.

Features and Benefits

•	Code is C callable, relocatable, and SPOX compatible
•	10 individually-controlled bands per channel
•	Equalized spectrum displayed real time
•	User definable to stereo or mono operation
•	Balance (pan) and master gain control

Processor and System Specifications

•	Memory requirement: 4-kwords program, 3-kwords data
•	Processor loading: (33-MHz TMS320C3x with zero-wait-state SRAM) 55% stereo, 27% mono
•	Minimum analog requirement:  TLS32044 or similar 14-bit, 8-kHz AIC
•	Ready to run on the Elf DSP Platform from Atlanta Signal Processors
•	Portable to any TMS320C3x target platform

Usage Limitations or Performance Considerations

•	None

Algorithm Verification

•	There are no international standards for this algorithm. However it has been extensively tested.

Availability

•	Written by Texas Instruments and available now through Atlanta Signal Processors.

Company Background and Contact Information

Atlanta Signal Processors was founded in 1981 by Ronald W. Schafer, Thomas P. Barnwell III, and 
Russell M. Mersereau, three Professors of Electrical Engineering at the Georgia Institute of 
Technology with over 80 years of experience in the field. The company has focused its efforts on 
developing tools for professional signal-processing design engineers and now offers digital 
signal-processing hardware and software products to DSP designers worldwide.
Contact:	Atlanta Signal Processors, Inc.
		1375 Peachtree St. NE, Suite 690
		Atlanta, Georgia  30309-3115
		(404) 892-7265
		Fax: (404) 892-2512
		e-mail: aspi@aspi.com