I have met with David to discuss the consent form, questionnaire and instructions form. We have made the first round of changes to these forms and sent them to Catherine Guastavino for review. Upon return to us, we will send the forms to Ich.
We are now waiting for the MAX patch to be configured for our test. We should receive this within the week, and we can begin the testing process.
Tuesday, October 19, 2010
Monday, October 11, 2010
week of: 10/05/2010
Potential test audio for the project has been provided to project members for review. The four albums are: Pink Floyd: Dark Side of the Moon, Holst: The Planets, The Alman Brothers Band: At Filmore East, and Santana: Abraxas. We will now select from the 4 albums excerpts that will be appropriate for the study. Previously we discussed finding musical examples that express a clear picture of the dynamic range of the recording, space, as well as rich and deep bass, and shimmering in high percussion.
The next stage of the process is to perform a pilot double-blind test to determine if the audio from the 2 tests is similar enough to begin actual testing. As well as taking the test ourselves, we will ask my labmates in the DDMAL to take this test in the next week. At present we are adjusting the MAX patch used in prior studies to work with our current study. Once done, we would like to use a listening room in the MPCL. I will contact Ichiro about this tomorrow.
NOTE: looking back I cannot find anywhere that I have mentioned that we have decided against a comparison of MM vs. MC cartridges. We have replaced the Ortofon OM20 (MM cartridge) with a Denon DL-103 (MC cartridge). We have also added an Elevator EXP as a step-up amplifier. This decision was made in an attempt to find a closer match between the outputs of both systems. After connecting the expensive turntable (w/ expensive cartridge) to the moderately priced GSP Jazz Club and GSP Elevator EXP. The result was that the output of this hybrid system sounded much more similar to the expensive system than the fully moderate system. We then assumed that the only remaining variables were the turntables themselves and the cartridge/step-up amplifier.
Potential test audio for the project has been provided to project members for review. The four albums are: Pink Floyd: Dark Side of the Moon, Holst: The Planets, The Alman Brothers Band: At Filmore East, and Santana: Abraxas. We will now select from the 4 albums excerpts that will be appropriate for the study. Previously we discussed finding musical examples that express a clear picture of the dynamic range of the recording, space, as well as rich and deep bass, and shimmering in high percussion.
The next stage of the process is to perform a pilot double-blind test to determine if the audio from the 2 tests is similar enough to begin actual testing. As well as taking the test ourselves, we will ask my labmates in the DDMAL to take this test in the next week. At present we are adjusting the MAX patch used in prior studies to work with our current study. Once done, we would like to use a listening room in the MPCL. I will contact Ichiro about this tomorrow.
NOTE: looking back I cannot find anywhere that I have mentioned that we have decided against a comparison of MM vs. MC cartridges. We have replaced the Ortofon OM20 (MM cartridge) with a Denon DL-103 (MC cartridge). We have also added an Elevator EXP as a step-up amplifier. This decision was made in an attempt to find a closer match between the outputs of both systems. After connecting the expensive turntable (w/ expensive cartridge) to the moderately priced GSP Jazz Club and GSP Elevator EXP. The result was that the output of this hybrid system sounded much more similar to the expensive system than the fully moderate system. We then assumed that the only remaining variables were the turntables themselves and the cartridge/step-up amplifier.
week of: 9/29/2010
David and I met to record a few records, and adjust the parameters of each system. An immediate observation is that the fixed output of the Steelhead (the preamp from the more expensive system) is much louder than the output of the Jazz Club and Elevator EXP (less expensive preamp+step-up amplifier). As the number of possible parameters to tweak on the Jazz Club and Elevator EXP combination was limited to resistance and capacitance settings (which are going to be held fixed due to the cartridge manual specifications), we have outlined 2 potential adjustments:
Repaired links on MAQ site in recording section here, and changed categories from Classical, Jazz, Rock, Pop to Classical, Jazz, and Contemporary.
David and I met to record a few records, and adjust the parameters of each system. An immediate observation is that the fixed output of the Steelhead (the preamp from the more expensive system) is much louder than the output of the Jazz Club and Elevator EXP (less expensive preamp+step-up amplifier). As the number of possible parameters to tweak on the Jazz Club and Elevator EXP combination was limited to resistance and capacitance settings (which are going to be held fixed due to the cartridge manual specifications), we have outlined 2 potential adjustments:
- use the fixed out of the Jazz Club and Elevator EXP combination as the reference level for the volume setting using the variable out of the Steelhead.
- attach the volume knob to the output of the Jazz Club so that each of the systems have variable output. Following this step, perform a group of experts tests to determine the most agreed-upon volume level for the listening tests.
Repaired links on MAQ site in recording section here, and changed categories from Classical, Jazz, Rock, Pop to Classical, Jazz, and Contemporary.
week of: 9/19/2010
Collected recordings used for developing comparison between 2 systems. Created recordings page on the MAQ site here, and edited the equipment page to have a link to the recordings page here.
Created account for David Weigl, and shared blog information with him. Discussed the AP2700 and various preamplifier tests run previously on this blog.
David and I will meet in the next week to do some vinyl recordings, and adjust the preamp volume levels for the comparison.
Collected recordings used for developing comparison between 2 systems. Created recordings page on the MAQ site here, and edited the equipment page to have a link to the recordings page here.
Created account for David Weigl, and shared blog information with him. Discussed the AP2700 and various preamplifier tests run previously on this blog.
David and I will meet in the next week to do some vinyl recordings, and adjust the preamp volume levels for the comparison.
Meeting: 9/14/2010
This meeting was held to discuss the next stages of our current perceptual test, which is to determine if expert listeners are able to differentiate between 2 vinyl record playback systems of differing price ranges. Each system includes a cartridge, turntable, preamplifier, and interconnect cables. The meeting was attended by Ichiro Fujinaga, Catherine Guastavino, David Weigl, and myself (Jason Hockman). The following are notes take from the meeting:
We will perform a study that will test participants' discrimination through preference testing.
This test will be based on a preference of system 1 or system 2, however subjects will also be tested using a comparison of different recordings of the same system, due to the variability inherent in the analog recording process. More specifically, we feel it necessary to include this "A1-A2" testing because playback of vinyl records can result in clicks and pops which may be found in different places within the digitally recorded timeseries, as well as possibly audible record degradation. Subjects will be informed in the preamble of the experiment that this will be part of the test, so they will not feel deceived by the test setup.
In a previous listening test (see the MP3 study here) started w/ 40 mins - 1 hour of audio material to listen to. Subjects were allowed to listen as many times as they wished, and could move between listening examples. We will adopt a similar structure for our experiment.
So how will we choose the files? is there a particular type of sound we are looking for? how long will the files be? The previous study used 5-12 sec. clips. Our study will instead utilize longer clips, as audiophiles will most likely require longer clips for analysis, but this makes the number of different clips heard overwhelming.
The final decision was to identify from our library 8 audio excerpts, of approximately 15 seconds each.
The participant should be able to switch between the 2 systems with a button. Upon pressing the button, there should be a fade-out of the first track followed by a 200-ms silence buffer and fade-in.
The interface should consist of this A/B switching button, a start (from beginning) button, as well as play, pause. Not discussed in the meeting, but assumed by myself is the need of "stop" and "next sample" buttons.
We will need background and response questionnaires, and receipt forms. Catherine has these forms from the previous MP3 experiment, and she will send these to David.
Timeline:
To do:
This meeting was held to discuss the next stages of our current perceptual test, which is to determine if expert listeners are able to differentiate between 2 vinyl record playback systems of differing price ranges. Each system includes a cartridge, turntable, preamplifier, and interconnect cables. The meeting was attended by Ichiro Fujinaga, Catherine Guastavino, David Weigl, and myself (Jason Hockman). The following are notes take from the meeting:
We will perform a study that will test participants' discrimination through preference testing.
This test will be based on a preference of system 1 or system 2, however subjects will also be tested using a comparison of different recordings of the same system, due to the variability inherent in the analog recording process. More specifically, we feel it necessary to include this "A1-A2" testing because playback of vinyl records can result in clicks and pops which may be found in different places within the digitally recorded timeseries, as well as possibly audible record degradation. Subjects will be informed in the preamble of the experiment that this will be part of the test, so they will not feel deceived by the test setup.
In a previous listening test (see the MP3 study here) started w/ 40 mins - 1 hour of audio material to listen to. Subjects were allowed to listen as many times as they wished, and could move between listening examples. We will adopt a similar structure for our experiment.
So how will we choose the files? is there a particular type of sound we are looking for? how long will the files be? The previous study used 5-12 sec. clips. Our study will instead utilize longer clips, as audiophiles will most likely require longer clips for analysis, but this makes the number of different clips heard overwhelming.
The final decision was to identify from our library 8 audio excerpts, of approximately 15 seconds each.
The participant should be able to switch between the 2 systems with a button. Upon pressing the button, there should be a fade-out of the first track followed by a 200-ms silence buffer and fade-in.
The interface should consist of this A/B switching button, a start (from beginning) button, as well as play, pause. Not discussed in the meeting, but assumed by myself is the need of "stop" and "next sample" buttons.
We will need background and response questionnaires, and receipt forms. Catherine has these forms from the previous MP3 experiment, and she will send these to David.
Timeline:
- recordings and pilot will be done in October
- study will take place in November
To do:
- book headphones
- once headphones are booked, verify the difficulty in differentiating between 2 systems.
- contact Harold about our timeline and requirements for the critical listening room for November
- set David up with a MAQ page account
- make copies of music for Catherine, Ich, and David for selecting musical clips
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