Each sample was mounted in a Tony's SpeakEZ enclosure with a red wire to the + and a black wire to the - leads. Each lead and the speaker were sealed in the enclosure with silicone and the enclosure labeled with the individual speaker code.
- Each speakers output was measured with a sound level meter mounted 30 above the speaker and a CV value determined for a sound level of 55 db.
- Each speaker was tested against every other speaker in each its respective group with the CV values individually set and rated with a 1 for the winner and a 0 for the loser.
- Each test position on the test boards was set-up with a rotary switch to test for the effects of various capacitors from 47µF to 220µF.
- During the listening test emphasis was put on the exhaust, as it is the sound that is most often heard with the whistle, bell, and blow-down given secondary consideration. Where there was no clear winner comparing exhaust, the whistle, bell and blow-down were given preferential consideration.
- Each test was completed with a team of no less than three people. The team discussed what was heard and had to agree on which of the two speakers in each test was the winner. If there was a tie in the comparisons, both speakers received a rating of 1.
- As each group completed their testing the scores were totaled and the speaker in each group receiving the most points declared the winner and all other speakers in the group were rated in the order that they scored.
- The results of each testing group were added together and the total values ordered from highest to lowest. Each testing group was unaware of the results of every other group to maintain subjectivity
The results were very interesting. In all groups but one, the winners were consistent. In this one group the winner differed by only one point between the groups. The results identified the best speakers in each group, which all teams agreed had sound significantly better than those currently available. We also found that all samples tested sounded better with the 220µF capacitor than any other value. We also found that any value higher than 220µF the improvement was insignificant. The smaller values worked, but if you can fit the 220µF use it, or the biggest size you can fit.
Regardless of your installation, you can be assured that using our installation, muting techniques, and capacitor recommendation you can start with the best possible speaker. In the future we hope to be testing new speakers as they become available and exploring various combinations of sizes and wiring solutions.
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