AES Journal Forum

Requirements for Low-Frequency Sound Reproduction, Part II: Generation of Stimuli and Listening System Equalization

Document Thumbnail

In part I of two papers the requirements for low-frequency sound reproduction were investigated by the variation of lower cutoff frequency and slope and by the introduction of different levels of amplitude ripple and group delay ripple in the passband of a high-performance sound reproduction system. Listening tests were performed at three different sound pressure levels using both loudspeakers in an anechoic chamber and headphones in an audiometric booth. Two reproduction setups were used to confirm that equal results of the listening tests could be obtained in the two cases when proper equalization was implemented. It is described how DSP was used to generate stimuli and perform equalization of the two reproduction setups. The shape and magnitude of amplitude and group delay ripple were derived from room simulations of an IEC 268-13 sized room with varying reverberation time. Proper equalization included the introduction of head-related transfer functions in the signal path to the headphones. This ensured that the sound pressures at the ear drums were very similar in two cases: a person sitting in front of the loudspeakers in the anechoic chamber and a person wearing headphones in the experimental booth. Level calibration was performed on both setups using pink noise. The nonlinearities measured in the physical loudspeakers were introduced into the signal path to the headphones using a nonlinearity simulator program.

JAES Volume 50 Issue 7/8 pp. 581-593; August 2002
Publication Date:

Click to purchase paper as a non-member or you can login as an AES member to see more options.

No AES members have commented on this paper yet.

Subscribe to this discussion

RSS Feed To be notified of new comments on this paper you can subscribe to this RSS feed. Forum users should login to see additional options.

Start a discussion!

If you would like to start a discussion about this paper and are an AES member then you can login here:

If you are not yet an AES member and have something important to say about this paper then we urge you to join the AES today and make your voice heard. You can join online today by clicking here.

AES - Audio Engineering Society