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Rehdeko & Harbeth lover
- Μηνύματα
- 4.983
- Reaction score
- 11.435
Καλά τα λένε τα μαστόρια, αλλά εγώ ένα εχω να πω: τα 100 (με 12" γούφερ) τα τερματίζω πολύ εύκολα, σε λογικές εντάσεις και με λογικό target curve.Ας διαβάσουμε και την άποψη μιας άλλης ΕΓΚΡΙΤΗΣ εταιρείας στο θέμα αυτό...και ας αποφασίσει ο καθένας μόνος του.
.........This section aims to clarify some of the issues surrounding the use of Bass Management (or bass redirection as it is sometimes known) in ATC multichannel systems.Topics discussed apply to the whole range of ATC systems and can be used for guidance when making installation decisions. Differences in professional and domestic requirements dictate slightly different approaches to Bass Management. In the recording studio, the primary aim is to achieve a result which will transport well to a range of domestic equipment and listening environments, whilst retaining the artistic intentions.These notes however focus on the needs of the domestic user which are rather more particular.The primary function of Bass Management in domestic applications (home theatre or multichannel audio only reproduction) is to increase the dynamic range, or the total sound pressure that can be delivered by the speaker system. However, depending on the performance of the loudspeakers in use, this priority may not be appropriate in some situations – this is commonly the case when using ATC loudspeakers. Switching off bass management in the majority of AV processors is simply a case of ensuring that the Sub-woofer output is turned “ON” and that all satellite speaker size options are set to “LARGE”.
The advent of multichannel reproduction technology in the home has led to the desire for inexpensive and robust speaker systems which can reproduce high sound pressure levels. Unfortunately the latter two requirements are in direct conflict with the former. Obviously, the simplest way of reducing the retail price of a product such as a loudspeaker is to cut back on the quality of the components used.
However, when designed properly, there is a direct relationship between the cost of a moving coil loudspeaker and its potential dynamic range.This can be attributed to a number of factors. For example, a drive-unit’s metal parts act as a sink for the heat generated by its voice coil, so as the mass of steel used is reduced for cost purposes, so the speaker’s ability to handle power is degraded. Magnet size and diaphragm area also tend to be reduced in an attempt to cut costs. Again, the trade-off is efficiency and dynamic range, both of which suffer as the compromises are made.
A convenient way of helping a low power system to deliver more sound pressure is to divert the potentially more damaging low frequencies away from the vulnerable speakers and into a sub-woofer. Bass management was devised to perform this task in the digital domain. It is a system of software filters and gain controls commonly fitted to AV processors/decoders that can redirect low frequencies away from the satellite speakers
(left, centre, right, surround left and surround right in a 5.1 configuration) and route it to the dedicated low frequency channel. Because the processing is done in software it is virtually free of cost and thus attractive to those who wish to maximise the dynamic range of a modest speaker system.
Compromises
As described earlier, Bass Management was devised for domestic use as a means of extracting more performance from cost- sensitive systems. However in high quality audio systems it should be avoided. The improvement in dynamic range that may be achieved with Bass Management is not without side effects and in high quality systems these side effects are significant.
The reasons for avoiding its use in high quality systems, such as ATC systems, are these:
■ High quality systems have enough dynamic range and bass extension without the use of Bass Management. Less software processing of the source material implies less potential for undesirable artefacts.
■ Without accurate knowledge of the acoustic character of satellite and subwoofer it is impossible for Bass Management to achieve a flat overall frequency response. Similarly the phase response will be unpredictable.
■ Bass Management encourages the crossover frequency between subwoofer and satellites to be above the onset of directionality in the subwoofer output.The resulting ability to hear the location of the subwoofer is clearly to be avoided.
■ When a significant proportion of the frequency range is separated from the satellites and passed to the subwoofer, any difference in the dynamic behaviour between the two types of loudspeaker will cause the system frequency response to change with output level.
■ The addition of filter slopes to the existing roll-off shapes of the loudspeakers may incur time-domain ringing and audible colouration.
Conclusion
There is a good argument for the use of Bass Management in modest, cost sensitive systems with restricted dynamic range. However, when applied to high quality systems the side effects are likely to be intrusive.We strongly recommend that Bass Management should NOT be used with ATC loudspeakers in domestic applications.
Καλημέρα....
Αν θέλει κάποιος δυνατή ένταση, διαθέσιμο headroom και καμπύλες φλετσερ μανσον, θέλει οπωσδήποτε σαμπ(ς).
Τώρα, καλό είναι το σαμπ να είναι πιο ακριβό από το δορυφόρο, όπως λέει και ο ηαρ ;-) Do the math ;-)
