Tone burst response of amplifiers to determine some properties of their dynamic behaviour

An amplifier should have a response which, within its operational range, should not depend on the strength of the output signal. Is that always the case? Read the findings of some measurements in DynamicResponseAmplifiers.pdf.

pdfDynamicResponseAmplifiers.pdf

The current through loudspeakers when excited with tone-burst signals

In order to get a better understanding of the interaction between the amplifier and the loudspeaker, measurements of the current through a bass-reflex loudspeaker have been made and these have been compared with the calculated current. The results can be read in CurrentBassReflex.pdf.

pdfCurrentBassReflex.pdf

Review in the Dutch HiFi magazine ‘Music Emotion’ of July 2017

In the edition of the Dutch HiFi magazine ‘Music Emotion’ of July 2017, a review of the combination of the control and power amplifiers of ‘Temporal Coherence’ has been published. The findings of the reviewer are laid down in Temporal Coherence Amplifiers.pdf and the pictures of the original review can be found in the Dutch version.  

pdfMusic-emotion-juli-2017-Temporal-Coherence-amplifiers.pdf

Presentation Hans van Maanen AES Berlin 2017

During the Convention of the Audio Engineering Society in Berlin (May 2017), a workshop has been held on the audibility of the temporal response  and temporal resolution of audio systems. The presentation of Hans van Maanen can be found at pdfWorkshop3.pdf

Presentation Mike Turner at AES Berlin 2017

During Workshop #3 at the Audio Engineering Society Convention in Berlin (May 2017), Mike Turner presented his ideas and plans to (strongly) improve the low frequency response of loudspeakers. This presentation is now available. It dives deeper into the theory, but to those readers, who think it will be (too) difficult: it includes also a number of very illustrative figures of the temporal response which are certainly worthwhile to study in more detail.

pdfAES Berlin 2017 v2.pdf.

Feedback

In certain high-end circles, feedback has a bad reputation. Regarding the theory that feedback improves the specifications of equipment, this is rather surprising. This paper analysis the problems with feedback and comes to the conclusion that feedback can introduce audible artefacts when feedback is not applied properly. However, feedback can improve the perceived quality of equipment, but it is no miracle cure.

pdfFeedbackHvM

Listening impression Music Emotion

Music Emotion (a Dutch audio magazine) has published a 'listening impression' of the Diamant
system in its December (2016) issue. We are very pleased with the findings of the reviewer, but
you can read for yourself in pdfImpressionOfListeningDiamant.pdf. For the pictures we refer to the
Dutch version pdfLuisterImpressie.pdf

Distortion

Distortion, generated by electronics, is even at low levels audible and annoying for human hearing.
"Temporal Coherence" strives for the lowest possible level and at least as annoying to human hearing
as is practical. To that end, a number of innovative methods have been developed, which are explained
in simple terms in this article.

pdfDistortion.pdf

Findings Home Video Test

The magazine "Home Video Test" has reviewed the Control Amplifier, Power Amplifier and Headphone Amplifier of "Temporal Coherence". The reviewer was not really happy that he had to turn in the equipment...... His findings are reported in the issue of February 2015 (Dutch version: pdfHVT0215.pdf, English version: pdfHVT0215English.pdf).

Amplifier Issues

Although the specifications of amplifiers are usually significantly better than those of loudspeakers, different amplifiers are qualified with large differences. This paper tries to identify a number of causes of this paradox without pretending it is the final answer. It is rather meant to stimulate the discussion and reactions are more than welcome.

pdfAmplifierIssues.pdf

Concepts of the Diamond and Pyramide audio systems

Temporal Coherence has demonstrated its "Pyramide" system at several audio clubs in The Netherlands. To elucidate the backgrounds, this presentation has been given. A number of sheets have been added to compensate the lack of explanation by the speaker.

pdfPresentation2014.pdf

Home Video Test of July 2014

On the contents page of Home Video Test of July 2014 it said "During the listening session at the triumvirate of Temporal Coherence it became more than clear that the loudspeaker design approaches the ideal".

pdfHVT0714English.pdf

Loudspeakers and Headphones in the High Resolution Audio Era

The high resolution digital formats are an improvement over the CD-format, which has audible deficiencies. But to express the advantages clearly, the loudspeakers, especially the tweeters, and headphones, have to fulfil a number of requirements. In this paper, presented at the AES conference in Helsinki, Finland, in August 2013, these requirements are underpinned and elucidated. It shows that there are still many shortcomings.

pdfHelsinkiTC.pdf

Impedance compensation of loudspeakers

Paper for the AES conference in Amsterdam (1994) to obtain an impedance compensation network in order to create a close-to-Ohmic impedance of a electro-dynamic loudspeaker unit in an acoustic box (in English).

pdfAUTOIMPE.pdf

Influence of loudspeaker impedance on cross-over filter

The influence of the output impedance of a power amplifier on a passively filtered loudspeaker has further reaching effects than just the low-frequency response. It has also an effect on the cross-over filter itself, as is explained in this paper.

pdfOutImped.pdf

Audibility of high-resolution digital audio

At the 128th conference of the Audio Engineering Society (London, 22 - 25 May 2010), a workshop was held about testing for the audibility of the "High Resolution formats for Digital Audio", like the SACD and the blue-ray 192 kHz / 24 bit. A panel of 6 experts gave their view on the way to do it and why high resolution formats give an audible improvement. This is one of the introductory papers, the other one is "HighReso.pdf" by Hans van Maanen.

pdfHighReso.pdf

pdfPAPER Subjective Sound Quality evaluation.pdf

Time smear by cross-over filters

"Time smear occurs at unexpected places in audio systems. One place, which is often overlooked, is the cross-over filtering in loudspeakers. This article shows that serious problems can arise because of incorrect phase responses of such filters, which can easily introduce audible errors in the reproduced sound (in English)."

pdfCross-Over-Time-Smear.pdf

RIAA correction amplifier

Description of the RIAA (record cutting) correction for different types of pick-up cartridges, including a novel approach for the correction of magneto-dynamic cartridges (in Dutch).

pdfRIAA1971.pdf

Active loudspeaker systems

Paper on the advantages of active loudspeaker systems, compared to passive designs, including the temporal responses of such systems (in English).

pdfActive4.pdf


Description of active cross-over filters for loudspeakers which have a correct behaviour in both frequency and time domains (in Dutch).

pdfAKFI1979.pdf

Mechanical resonance compensation of pick-up cartridges

Description of the first circuit to correct the resonance of the magnet on its stylus of a moving magnet (magneto-dynamic) pick-up cartridge in order to improve its response in both frequency and time domains (in Dutch).

pdfMERK1979.pdf


Description of the processor, which corrects the mechanical and electrical behaviour of a moving magnet (magneto-dynamic) pick-up cartidge and corrects the RIAA (record cutting) characteristic. Based on RIAA1971 and MERK1979 (in Dutch).

pdfMERK1980.pdf