MK Sound LCR-55 Mkii User Manual
Bookshelf-75/Center-75/LCR-75/LCR-55
page 4
and connect the Negative (-) lead from your amplifier or receiver to the BLACK (-) INPUT terminal. See Figure 1.
4. CABINET ALIGNMENT TUNING PLUG (BOOKSHELF-75 ONLY)
On the front baffle of the Bookshelf-75 speaker is a large (2" diameter) plug that can be easily removed or inserted.
DO NOT THROW THIS PLUG AWAY. This plug can be used to adjust the performance of the speaker to fit your system
needs or personal preferences.
needs or personal preferences.
When the plug is inserted into the speaker cabinet, the plug seals the speaker port, making the Bookshelf-75 a
SEALED BOX speaker. When the plug is removed from the speaker cabinet, the port is open, making it a VENTED
BOX speaker. When you use the Bookshelf-75 as a vented box speaker, the port adds a couple of dB extra midbass
output around 80 Hz. Here are the advantages and disadvantages of each mode, with recommended applications.
Feel free to experiment with both configurations to see which one you prefer.
BOX speaker. When you use the Bookshelf-75 as a vented box speaker, the port adds a couple of dB extra midbass
output around 80 Hz. Here are the advantages and disadvantages of each mode, with recommended applications.
Feel free to experiment with both configurations to see which one you prefer.
SEALED BOX (Plug inserted in port):
If you are using a subwoofer with your Bookshelf-75s, operate the Bookshelf-75 as a sealed box. This will give
you the best transition of sound between the Bookshelf-75 and the subwoofer. If you are using a high-pass filter (M&K
HP-80 or VF-80), you must operate the Bookshelf-75 as a sealed box in order for the filter to operate optimally.
HP-80 or VF-80), you must operate the Bookshelf-75 as a sealed box in order for the filter to operate optimally.
The sealed box configuration gives you the best transient response, the tightest mid-bass, and the flattest
frequency response. If you are using the Bookshelf-75 as a full-range speaker (without a subwoofer), we recommend
that you use the Bookshelf-75 as a vented box speaker. Again, we encourage experimentation.
that you use the Bookshelf-75 as a vented box speaker. Again, we encourage experimentation.
VENTED BOX (Plug removed from port):
Removing the plug increases the mid-bass output of the Bookshelf-75 by a couple of decibels in the 80 Hz region,
which increases the perceived bass. This is recommended when the system has no subwoofer. The vented box
configuration generally gives the most satisfying bass when the Bookshelf-75 is being used as a full-range speaker.
configuration generally gives the most satisfying bass when the Bookshelf-75 is being used as a full-range speaker.
5. THE M&K HIGH-FREQUENCY PRISM SYSTEM
Your LCR-55MkII and Center-55MkII speakers utilize M&K's exclusive High-Frequency Prism System to
optimize imaging and coverage of sound throughout the listening area. This system is designed to take into account
the effect of the curved mesh metal grilles on your speakers. Therefore, your speakers are designed for the best sound
the effect of the curved mesh metal grilles on your speakers. Therefore, your speakers are designed for the best sound
FIGURE 1
SPEAKER WIRING
Bookshelf-75/LCR-55MkII/Center-55MkII/LCR-45