The bit Tune is an advanced measurement tool, and over the years it has evolved a few times, as we have added functions to it.

Some people who tried it years ago – often only to set up a bit Ten or bit One – haven’t ever seen the full feature set available to users today. Read on to learn what the bit Tune 3.1.0.1 SW can do for you.

ACOUSTIC REAL-TIME ANALYSIS

Bit Tune’s Real-Time Analysis tool is now unlocked for all users. The RTA is now capable of multiple resolutions up to 1/48th octave, and the graph can be viewed in either bar or line mode. (Line mode is really useful when comparing various measurements, as we will discuss below).

Viewing RTA measurements in very high resolutions can be confusing, as you see many artifacts – especially at higher frequencies – which really shouldn’t be chased after during the tuning process. Using the higher-resolution is most powerful when using HSM Sweep (below) or when performing electrical measurements (also below!) If you want to see the effects of phase cancellations – especially comb filtering caused by mistimed arrivals – higher resolution is very helpful.

The bit Tune supports saving RTA measurements and then viewing them at the same time as live measurements. This is very helpful when making left and right sides match in level and response, for example – or when looking for phase cancellations. The new Target Curve – HAC-Universal – has been well-reviewed by our testers, and sounds great in cars. The Target Curve editing tool is much improved, and also supports exporting and importing so dealers can create their own curve if they like – from scratch, or based on an existing curve.

The RTA graph window now has the ability to display the precise amplitude and frequency for any point on the graph. This makes analysis of a measurement much simpler, as well as the comparison of two measurements. A few clicks and you know exactly how many dB of EQ are needed, and at what frequency.

The built-in Signal Generator function is enabled when in RTA mode, if you want to use it instead of a recorded track.

HSM SWEEP

HSM Sweep isn’t a live real-time measurement – like RTA measurement- but it uses the RTA user interface. Use HSM Sweep to take a 5-microphone spatially-averaged measurement. It takes less than a minute to perform, and the results allow faster tuning with better results.

Now that we have HSM Sweep, the higher-resolution mode of the acoustic RTA is even more useful – since HSM Sweep will remove the nonlinearities in the higher frequencies which are visible in higher resolution, but not really actionable in most cases (since they are connected to measurement microphone location, and are thus ignored by the human hearing system).

IMPROVED ACOUSTIC RTA MAIN FEATURES:

• Full-screen mode for better viewability
• Load target curves (also in Offline mode)
• Save measurements to your PC
• Load and view saved measurements
• View saved measurements and live measurements at the same time (useful for comparing left and right sides, comparing one channel to both channels together, or comparing initial response to tuned response)
• Use the new cursor tool to check precise frequency and amplitude at any point (very useful for quantifying the differences between saved and live measurements)
• HSM Sweep uses the Head Simulation Microphone array to create a 5-microphone spatial average in under 60 seconds (displaying relevant tuning information while removing spurious higher-frequency artifacts associated with single-microphone locations)
• Resolutions up to 1/48^th octave available
• Combining HSM Sweep with higher resolution modes delivers detailed information at low frequencies while removing spurious information at high frequencies, delivering the most relevant data to the tuning technician

OSCILLOSCOPE

The bit Tune’s oscilloscope function is also now available for all users, making signal testing and gain settings simpler and safer.

ELECTRICAL RTA WITH SUMMING

Bit Tune now uses the RTA screen for displaying electrical frequency response – and it can handle up to 1000 volts of signal! (This screen is more familiar to technicians than the spectrum analyzer screen, which is still supported). With the bit Tune module, a power cord, a USB cable to your PC, and the probes (included) you can test speaker-level signals to answer all three question of OEM analysis (what’s the voltage, what’s the frequency response, and what’s the frequency range?) This speeds up channel identification immensely.

Since Bit Tune has two electrical inputs, the Electrical RTA supports summing these two channels to determine if there is phase or time processing in use, and to properly predict the polarity to observe when summing OEM amplified channels together. The electrical RTA supports sum and difference modes, so you can confirm proper polarity without changing your electrical connections – simply by comparing the two channels summed to the two channels subtracted!

The Electrical RTA shows the voltage levels for both channels, regardless of which channel is being viewed in the frequency-response window. It uses either the RCA inputs or the attenuated speaker-level inputs, as needed.

NEW ELECTRICAL RTA MAIN FEATURES:

• Full screen mode for better viewability
• 10/100/1000V input ranges accommodate any amplifier or preamp signal
• X2 option for more detailed viewing at low volumes
• Resolutions up to 1/48^th octave show cancellations caused by delay or phase equalization
• Measure and view frequency response, peak-to-peak voltage, and RMS voltage on one screen
• Measure and view two channels simultaneously (Left/Right, High/Low, etc)
• Save measurements to your PC
• Load and view saved measurements
• View a saved measurement and a live measurement at the same time
• View saved measurements Offline
• View the sum, or the difference, of the two channels together (allows easy polarity checking, proper summing polarity, and phase comparison)
• Use the new cursor tool to check precise frequency and amplitude at any point (makes comparison of saved and live measurements, or individual to summed measurements, easy to quantify)
• Use the Transparency control to better view multiple channels when using Bar mode
• Use Line mode to easily view and compare multiple traces simultaneously (L, R, L+R, for example)

ACOUSTIC AND ELECTRICAL TESTER 

The bit Tune uses the LPM microphone to test speaker polarity acoustically (speakers all connected properly are critical to a well-tuned system). Electrical polarity can be ensured by using the summing feature of the electrical RTA.

When used in conjunction with bit Virtuoso, the Percept algorithm lets Mobile Phase Correction measure the acoustic phase at the listening position, and correct it using FIR filters (Virtuoso is the only aftermarket automotive DSP with FIR filters!) Get better phase linearity than ever before!

Read more on Mobile Phase Correction

APM IMPROVEMENTS

Option to choose the Audison target curves or other curves created by the user, besides the Moller curve. This allows scoring to be more relevant in the consumer environment, where various preferences exist.