Two modes are available for the set up of the bit One HD’s time delays:
◼︎ Basic Mode, the system time delays can be displayed by selecting the Channel Map loudspeaker from the main software screen. Then enter the distances (cm/inch) from the listening point, and the related “fine set” (ms).
Fig.1
◼︎ Extended Pop Up Mode,
by selecting the icon the extended menu for the set up of time delays will appear. This operating mode, as well as allowing a faster and easier data entry, will provide different views of the time delays according to the listening point, the farthest speaker, depending on the distance (cm/inch) or time (ms).
Fig.2
Preliminary remarks
Sound moves through the air at a speed of 343 mt/sec (1.125 ft/sec) and at the temperature of 20°C (68°F). If you know the distance from the sound emission point, you can then calculate the time sound takes to get to the listener’s ear. By default the bit One HD enables the entry/automatic calculation of time delays by entering the simple measurements between the listening point and the speakers by selecting the option “From Listening Point cm/inch”
It is however possible to enter the same time delays with respect to the listening point by entering the time value (ms-milliseconds), selecting the option “From Listening Point ms".
If instead of the distance from the emission point only the distance between the loudspeakers with respect to the farthest emission point is available, it is possible, by selecting the option “From Farthest Speaker cm/inch, once the farthest speaker is selected, to enter distances from the other speakers, and then fine-tune the remaining speakers of the system.
However, it is possible to enter the same time delays with respect to the farthest speaker by entering the time value (ms-milliseconds), selecting the option “From Farthest Speakers ms".
Switching between the 4 time delay entry modes is automatic, the software will automatically convert the values displayed on the Channel Map.
FINE SET AND PHASE DELAY
The delay assignment according to the distance calculation is theoretical. That is, small variations need to be applied due to small errors in distance measurement, due to the resonance inside the car compartment and, mainly, due to the speaker phase problem. Two speakers reproducing two areas of frequency one close to the other (ex. Woofer and Midrange), in their crossing area will simultaneously reproduce, at attenuated level, the same frequencies. Due to the different nature of the speakers, they will show a difference in phase that, for a short frequency interval, works like a time delay.
By acting on the “fine set” you can partly also correct problems of Phase Delay.
By acting on the “fine set” you can change the automatically set time delay. The delay that is varied adds up to (+ x.xx) or is deducted from (- x.xx) the value of the delay shown in the “Delay / default” window, which does not change the assigned value which is the one automatically assigned. Assigning a positive value ( + x.xx) with the “fine delay” means increasing the delay of that speaker and therefore moving it away from the listening point. Likewise, assigning a negative value (- x.xx) means decreasing the speaker’s delay and therefore moving it closer to the listening point.
If you try and give a negative value to the farthest speaker, an alert message will be displayed. By acting on “fine set”, the word “fds” will light up on the corresponding channel of the “Channel Map”, to inform the user about the entry on the highlighted channels.
8.7.2.1 TIME DELAYS ENTRY BASIC MODE
Switching from POP UP mode to the PC software normal display mode will only show the standard display of the menu described below.
By selecting a channel from the Channel Map, it will be possible to act on the parameters:
Fig.3
- Set Distance: to edit the selected loudspeaker distance (cm/inc) from the Channel Map.
- Fine Set (ms).
- Delay Default from Farthest Speakers.
Fig.4
1. choose the system listening point. To identify the listening point, choose an ideal point located at the center of the listener’s (driver or passenger) head. For the front central and rear central points choose an intermediate point between the two listeners.
2. measure the distance between each loudspeaker or group of loudspeakers and the listening point in a straight line (“as the crow flies”). For each loudspeaker choose the center of the mobile membrane as the emission point. For the groups of loudspeakers choose an intermediate point between them. Afterwards, fine-tuning can be performed by selecting the Fine Set function.
3. select the channel related to the loudspeaker under exam from the Channel Map and enter the related distance value on the Set Distance box from the Filter Settings menu.
4. repeat step 3 for each channel.
5. perform all the time delays settings, start the music reproduction and select the Fine Set box. If you move the values to positive or negative (except for the subwoofer as it is the farthest speaker), you can find the best time alignment that will ensure a correct acoustic scene. The fine set tuning can be managed through the multiple selection of the audio system emission front (Ie. Front Left Tweeter + Front Left Midrange + Front Left Woofer). Select the front (Left or Right) channels keeping the CTRL key pressed with the mouse pointer, then proceed to the fine set tuning. It is advisable to listen to different types of musical tracks (percussions, melodic etc.) for a much more correct evaluation of the different musical instruments coherency (space stability).
WARNING: if, once you have set the distances according to the “driver” listening point you click on the “passenger” listening point, the bit One HD will not re-calculate the delays according to the new reference point because the buttons available in the SELECT A CHANNEL diagram are merely descriptive and their only purpose is to remind you that you have set the delays for that listening point!
8.7.2.2 TIME DELAYS ENTRY POP UP MODE.
By selecting the icon , the customization menu of the output channel filters will appear as shown to the side. It will be possible to intervene to set the time delays by clicking on DELAY SETTINGS.
Time delays entry default mode “From listening Point cm/inch"
This setting is based on an automatic system that allows you to calculate the time it takes for the loudspeaker to reach the ear.
1. choose the system listening point. To identify the listening point, choose an ideal point located at the center of the listener’s (driver or passenger) head. For the front central and rear central points choose an intermediate point between the two listeners.
2. measure the distance between each loudspeaker or group of loudspeakers and the listening point in a straight line (“as the crow flies”). For each loudspeaker choose the center of the mobile membrane as the emission point. For the groups of loudspeakers choose an intermediate point between them. Afterwards, fine-tuning can be performed by selecting the Fine Set function.
3. select the channel related to the loudspeaker under exam from the Channel Map and enter the related distance value on the Set Distance box from the Filter Settings menu.
4. repeat step 3 for each channel.
5. perform all the time delays settings, start the music reproduction and select the Fine Set box. If you move the values to positive or negative (except for the subwoofer as it is the farthest speaker), you can find the best time alignment that will ensure a correct acoustic scene. The fine set tuning can be managed through the multiple selection of the audio system emission front (Ie. Front Left Tweeter + Front Left Midrange + Front Left Woofer). Select the front (Left or Right) channels keeping the CTRL key pressed with the mouse pointer, then proceed to the fine set tuning. It is advisable to listen to different types of musical tracks (percussions, melodic etc.) for a much more correct evaluation of the different musical instruments coherency (space stability).
Once all the speaker distances have been entered, it is possible to obtain automatically by clicking on the check boxes:
- From Listening Point (ms): the related delay between the listening point and the system speakers. If a fine set is entered, the value on the Channel Map will become red.
- From Farthest Speaker cm/inch: the related distance between the loudspeakers and the farthest speaker in the system.
- From Farthest Speaker ms: the delay introduced between the farthest speaker and the rest of the system. If a fine set is entered, the value on the channel map will become red.
- The software, in addition to offering the conversion of values according to the selected mode, will allow their adjustment, passing from one mode to another.
WARNING: if, once you have set the distances according to the “driver” listening point you click on the “passenger” listening point, the bit One HD will not re-calculate the delays according to the new reference point because the buttons available in the SELECT A CHANNEL diagram are merely descriptive and their only purpose is to remind you that you have set the delays for that listening point!
8.7.2.3 TIME DELAY SETTING PASS-THROUGH MODE.
In the case of the Pass-Through mode with selection of the Master input, it is also possible to manage time delays. It must be specified that if the bit One HD is interfaced to a source with time delays, it is advisable to intervene by acting only on the Fine Set. Once the time alignment procedure has been completed, it will be possible to intervene on the output equalizer (MASTER), to optimize the response of the system according to the level alignment at the various frequencies. For the auxiliary inputs Optical 1/2 and Aux instead it is possible to act on the time delays setup, as described in the previous paragraphs, since these inputs are not connected to the Master input.