November 25, 2008 . by Bill
Some quartz (battery operated) chiming clocks sound much better than others. A major factor of sound quality is the mounting of the speaker that produces the sound.
In some clocks, the speaker is mounted inside the case and the sound cannot project outward. These clocks have quiet, tinny sounding chime.
The best clocks have the speaker mounted over an opening in the case. The sound of these clocks is rich and full-bodied. The volume of sound can also be louder. Many Hermle clocks have the speaker mounted this way.
The photos below give examples of good and not-so-good speaker mounting.
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An excellent sounding quartz mantel clock, Hermle model 22825-i92115.
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The movement of the Hermle 22825-i92115.
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In the model 22825-i92115, the speaker is mounted over an opening in the bottom of the case. The case bottom acts as a baffle for the speaker, creating a rich, full chime sound
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Outside view of the bottom of Hermle model 22825-i92215, showing the cover over the speaker.
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An excellent sounding quartz wall clock, Hermle model 70687-N92215.
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Movement and speaker of the Hermle model 70687-N92215.
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In the model 70687-N92215, the speaker is mounted to an opening in the top of the case. The the top board acts as a baffle for the speaker, allowing good volume and clear, rich sound.
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A clock with the speaker mounted to the back of the movement (Hermle 70883-Q12214). The sound is not as good when the speaker is mounted this way.
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A clock with the speaker mounted to the back of the movement, and in which the back door covers the speaker, trapping the sound inside (Hermle 70734-Q12214). This causes the chime to be very quiet and without richness.
Brief Explanation:
When a speaker does not have a baffle around it, the sound waves generated by the front of the speaker cone cancel out the sound waves generated by the back of the cone below a certain frequency. With a small speaker such as used in clocks, all the bass response is lost in this way. Mounting the speaker on a baffle (such as a board) creates a longer path for the sound waves, reducing cancellation. The larger the baffle, the lower the frequency response extends. Even a small baffle will make the speaker sound much better.
See information about the Hermle 70687-N92215 Chiming Wall Clock
See information about the Hermle 22825-i92115 Chiming Mantel Clock

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November 26, 2007 . by Bill
I had a brand new Hermle clock (model 22835-002114) come back because the customer said it would not chime. He sent the batteries with it, and when I installed them, the clock would not chime or keep time. The batteries checked good on the tester, but would not make the clock work. As an experiment, I installed two brand new Duracell C batteries. The clock worked perfectly.
Examining several brands of battery, one can see that the bottom (negative) contacts are made differently.
AA cells: On some brands, the contact extends downward from the surrounding plastic covering, and these work fine. On some brands, the contact is flush with the covering, and these may not work reliably or at all in some clocks. Two brands of AA Cell that work well are Duracell and Rayovac.
C cells: Testing has shown that Duracell batteries work very reliably in clocks. Their negative contact extends further past the plastic covering then on some other brands, ensuring that it touches the clock’s contact.

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I recently added chime and strike sounds of many of the Hermle and Chelsea clocks to the Bills Clockworks web site. It was challenging to record the sounds and have them sound realistic. The microphone had to be located close to the clock (about 8″ away) or else too much background noise was picked up and the recording was not loud enough, but the closeness over-emphasized the mechanical noises from the movement (such as the click made near the end of the chime when the strike is being activated). In real life, the listener is not aware of these sounds when she is located several feet or more away from the clock.
A challenge was to make the sound buttons compatible with as many types of computers as possible. I did not want a sound player window to pop up, I wanted just a button that the user can click to play the sound. On some windows PCs, the user must give permission the first time a button is clicked. Macintosh computers that I have tested handle the sound fine.
Please test these sounds on your PC and let me know if they play. Also tell me the type of PC (Mac or windows), operating system (such as Windows XP or Vista), and the web browser (such as Explorer 6 or 7). You may leave a comment below. These two links will open a new window or tab in your browser:
Hermle Chime and Strike Sounds
Chelsea Ship’s Bell Strike Sounds
Thanks!

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