Background:
As some of you know, I recently acquired an (Akai) A&D GX-Z9000 cassette deck and tested it quickly in my 2nd system in the great room by plugging its output to the inputs on the front panel. I picked a dbx recorded cassette and played it on the Akai and there were two things I noticed. The metering was very much different than that of my Yamaha decks. When I played the cassette on the Akai with dbx engaged, it barely registered over +3db where as with the Yamaha, it was peaking regularly at 10+db. Seeing that, I perceived the output of the Akai deck to be substantially lower than any of my decks, especially the Yamahas. Its about how a perception/bias can alter our hearing perception.
Methodology
I conducted a measurement experiment using the SPL app on my iphone. I set the volume of the AVR to -25db, some arbitrary value and left it there. I used a dbx recorded cassette made on my Yamaha C300 and selected a point in the song where it would be easy to trigger on for relative consistency sake. I set the input to the Akai, measured the SPL and rewound the cassette. I switched inputs to the Yamaha K1000, played the cassette and measured at the same part of the song and rewound the tape. I switched to the Pioneer, repeated the process, and then to the Yamaha KX-1200 and finally the Yamaha C300.
Here are the screen shots Yamaha K1000, Pioneer CT-S99WR, Akai GX-Z9000, Yamaha KX-1200, and Yamaha C300 in that order
Dont look at the max values for comparison because its a peak that was caught by the app but not at that particular part of the song that I triggered on. The app remembers the last max value,
Conclusion
Remember that my perception was that the Akai was substantially weaker in output than all my other decks and this perception was stuck with me for 2 listening sessions prior to this experiment. As you can see from the crude results, the Akai has similar output levels as the Pioneer deck so my initial perception of the Akai being substantially weaker is not true. I new it would be weaker than my Yamaha KX-1200 based on previous listening sessions and using the same tape and scrambling to turn down the volume as I had the AVR cranked coming from the Pioneer. The 1200 has highest output of all my decks and is absolute beast that way. Notice I had to move the range to the 90db level where the measurements stayed at the 80db range for the rest of the decks. I can now listen to the Akai without worrying that something was wrong with its output.
