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Noise Problem Indicated in Computer Sound Cards Used as Hi-Fi Recording Devices

Matusiak M.

Journal of Applied Computer Science Methods

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2010

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Vol. 2 No. 2

191--199

EN

A sound reception is one of important human perceptions and a contact with the surrounded world. Now computer devices are the main equipment to almost perfectly record and playback a wide range of sounds. Music or sound cards play the central role in this process. The Author has tested several cards concentrating the attention specially on their external versions but internal versions were also investigated for comparison. Usually specially constructed external sound cards are better than much compromised internal versions built directly other electronic circuits on the computer mainboard. It was proved during experiments measuring noise parameters – not always. A simplicity of the construction and other digital circuits closeness create difficult conditions for a noiseless action but in a popular class equipment only. Three external cards, one of PCI interfaces E-MU - 0404 for studio recording and two of USB interface, potentially worse designed by Creative Labs - Sound Blaster Connect and by Lexicon - Alpha. All Hi-Fidelity requirements are performed by each card but noise levels are different. Conclusions are shortly presented here: 1. Built-in sound cards, specialized for Hi-Fi recording are better with noise parameters than external USB devices 2. The newer built-in card (Dell Studio laptop) is only a little bit worse than special professional card by Creative Professional (E-MU 0404) 3. USB cards include additional preamps (very useful) but present in noise charts ad-ditional interferences (peaks) and its noises are a few dB bigger 4. Newer USB cards (Lexicon Alpha) are much better than older (Sound Blaster Connect). The noise difference is up to 10 dB (abt. 3 times) Results are clearly shown using tables, charts and mathematical formulas derived from own experiments.

2

Termodinamicny aspekty elektricnych szumiv u tverdich tilach

Kolodij Z., Stadnik B., Jaciszin S.

Zeszyty Naukowe Politechniki Rzeszowskiej. Elektrotechnika

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2002

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z. 22 [192]

119-124

PL

Zaproponowano rozpatrzenie fluktuacji elektrycznych w ciałach stałych z pozycji energetycznej.

3

Algorytm projektowania badań symulacyjnych i eksperymentalnych systemu pomiarowo-kontrolnego

Nowakowski A.

Elektronika : konstrukcje, technologie, zastosowania

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2002

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Vol. 43, nr 11

11-13

PL

W artykule przedstawiono ważny z praktycznego punktu widzenia algorytm dotyczący konstruowania elektronicznych systemów pomiarowo-kontrolnych o podwyższonej odporności na zakłócenia, począwszy od etapu projektowania, przez wykonanie modelu, prototypu, a kończąc na etapie wdrożenia. Uwzględniono wymagania stawiane przez odnośne międzynarodowe normy. Przeprowadzone badania systemu pomiarowo-kontrolnego, według metodologii podanej w algorytmie, pozwalają na wyeliminowanie wielu błędów projektowo-konstrukcyjnych oraz wykonawczych, co w oczywisty sposób ma wpływ na zwiększenie niezawodności jego eksploatacji.

EN

In the article there has been presented an algorithm, important in practical applications, for designing of control and measurement system of enhanced noise immunity, starting from the design stage, through the model stage finishing with the stage of implementation. Relevant international standards were taken into consideration. Testing of a control and measurement system in accodance with the methodology of the algorithm allows for elimination of many design and manufacturing mistakes what enhances its reliability.