Απάντηση: Re: Αναζήτηση ηχείων για υπολογιστή - μουσική
Ναι, σε αυτον αναφερομαι!
Αυτα τα στοιχεια απο που προκύπτουν; Εγω διαβαζω:
Total RMS Power: 200W [FTC Rated Power]
Total Peak Power(RMS): 400W < 10% THD
Προκυπτουν απο τις μετρησεις που εγιναν και αναφερονται ολα αναλυτικοτατα στο παραπανω link που σου εδωσα.
Δεν αντιλεγω στα νουμερα που εδωσες, αυτα ειναι. Κοιτα ομως εκτος απο το PEAK και ποσο ειναι το Continuous Power.
Αν διαβασεις προσεκτικα, θα δεις οτι προκυπτουν τα νουμερα που σου εδωσα.
Σε περιπτωση που χαθηκες στις πολλες σελιδες που εχει παρακατω αυτο για το οποιο μιλαμε:
Z-2300 amplifier’s continuous power output capability
In order to produce 200W of continuous power, an amplifier will need a transformer that is capable of to deliver a minimum of 1.27 times the claimed wattage. Since Watt is volts multiplied by ampere, 200W of output requires 254 watts or 254VA transformer as a minimum requirement.
So, Z-2300’s supplied 150.9VA will produce a maximum of: 150.9/1.27 = 119W =~ 120W of continuous power @ 8 ohms @ 26 VDC
Since the ratio of power distribution between the subwoofer and the satellites are in the order of 1.71:1, the subwoofer will get 76W of continuous power while each satellite gets 22W of continuous power.
This becomes even more evident from the fact that the bass driver has a rated input power 80W, while the satellite speakers can handle anything between 20 to 40 watts.
The Total RMS Continuous Output Power of the four amplifier chips = 50(TDA7295) + 50(TDA7295) + 30(TDA7296) + 30(TDA7296) = 160W whereas the Total RMS Continuous Output Power of these four amplifier chips is 120W for Z-2300 since the the power supply limits the maximum power output.
Also these amplifiers will produce a lot of distortion & noise at the peak 160W power output. So, in order to produce distortion free, linear sound the amplifiers generally needs to reduce its output peak power by 25% or more. Using an amplifier with some extra “headroom” will help assure that only clean, undistorted power gets to your speakers. Reducing the maximum power from 160W to 120W Z-2300 creates a 25% headroom and justifies the stated system THD of better than 0.05% before clipping & signal to noise ratio of > 100dB.
Discrepancies about Power Output Figures
Remember that most audio amplifiers do not have power supplies capable of driving their rated power continuously. This holds absolutely true for all computer multimedia speakers systems & consumer home audio products. Only HiFi systems costing a lot of money have power supplies that can match the continuous power rating of the amplifiers.
This is because music is not like a continuous sine wave. It has peaks of intensity, then relatively quiet periods. If music has a 20dB dynamic range then if the peaks are 200W, the average power is probably around 5W.
A transformer can sometimes go well beyond its rated power output for small amount of time to handle these peaks of intensity. For example the 150.9VA transformer of Z-2300 can go up to 180VA to handle the peaks & produce 140W power for that moment.
If even further power is required to handle this peaks of intensity, say 200W, then the additional 60W is supplied by the two large 10,000uF, 35V power supply filter capacitors of Z-2300 for this short period of time. The filter capacitors can charge back up during the relatively quiet periods.
So the 150.9 VA transformer of Z-2300 is perfectly capable to deliver 120W of continuous power & can easily handle peaks reaching 200W.
That is the reason why Logitech states that Z-2300 have a Total RMS Power of 200W. Look at the absence of the “continuous” word. Except HiFi systems, you will always find these consumer audio companies talking about “FTC Rated Power”,“Total RMS Power”, “Power”, “Total Peak Power”, “System Power”, “Music Power”, “Peak Music Power Output (PMPO)”,…………….. and the list goes on. But you will never find them talking about “Continuous Power” which happens to be the actual power of the amplifier.
και μια τίμια ποιότητα...
