You Wanted To Know...
Please compare the three Bose® Panaray® Modular Bass enclosures?
The three Panaray® modular bass loudspeakers offer similar bandwidth with three SPL choices. Each provide a solution for different applications and are well matched to create full range solutions for a wide range of applications.
|
Bass Speakers |
MB24 |
MB12 |
MB4 |
|
Bandwidth |
40 Hz- 250 Hz |
40 Hz- 250 Hz |
40 Hz- 300 Hz |
|
Max SPL - pink noise @ 1m at rated power |
123 dB-SPL |
117 dB-SPL |
110 dB-SPL |
|
Peak SPL - pink noise @ 1m at rated power |
129 dB-SPL |
123 dB-SPL |
116 dB-SPL |
|
Power Handling |
800 Watts |
400 Watts |
200 Watts |
Handy Tips
Getting the Most Out Of Your Bass System.
We have all experienced it. You walk into a store or restaurant and you hear full, rich sound. You look up to the ceiling and immediately see the mid/high speakers, but you spend the next ten minutes trying to locate the bass enclosure. And to your surprise, there is only one! The store is perfectly covered with powerful bass.
This is an example of a single-point bass design that works. Unfortunately, we have all experienced the opposite as well. You walk in to an establishment and hear anemic mid/high speakers over your head. You search for a bass enclosure and finding it, you hear uneven bass that disappears once you walk more then 20 feet (6m) away. Either the design rules where not followed or distributed bass would have been a better approach overall.
Design rules for single-point bass are:
Rule 1 - Always try to boundary-load the bass enclosure against large, massive walls or ceiling to maximize bass output. One surface will increase bass output by 3dB; two surfaces: 6dB; three surfaces: 9dB.
Rule 2 - Mount the bass enclosure as high in the room as possible, always higher than the mid/high speakers. Keeping the listeners more equidistant from the bass enclosure minimizes bass localization.
Rule 3 - Never mount the bass enclosure so it is closer to the listeners than the mid/high speaker is. The bass enclosure should be no closer than 10 feet (3m) from the nearest listener location. If it must be closer to listeners, be sure to mount a satellite or mid/high speaker right next to it.
Rule 4 - Avoid mounting the bass enclosure in the center of any wall. Favor one side of the room or the other – never directly in the middle – and avoid the geometric center of the ceiling. Favor corners if possible. This will minimize cancellation caused by the room geometry.
Rule 5 - Surface-mounting the bass enclosure is much better than recessing it in the ceiling. Significant energy is lost above the ceiling.
Rule 6 - If more SPL is needed in systems that successfully use single-point bass, always mount the bass enclosures together. The acoustic centers of the bass enclosures should not be more than 2' 9" apart. This will ensure coherent summation below 200Hz. The enclosures will acoustically couple and act like a single, higher-output speaker and with no undesirable interference.
Some of the most common problems encountered with single-point bass are:
- Bass that is strongest near the bass enclosure and at the opposite side of the room – then drops off in the center of the room
- Spotty bass coverage with severe “holes” all over the room. A long, thin corridor-like room can cause this.
- Overall dimensions of the room that coincidentally causes significant cancellation
- Acoustically transparent construction (thin walls, suspended ceilings, and large volumes of air above ceilings) that allows most of the bass energy to exit the room
Following the above placement rules can greatly minimize or solve most problems. Another solution may be to add a second bass enclosure in an opposing corner of the room.
The two enclosures will energize the room in unique ways – each with peaks and dips in their respective direct-field coverage, but rarely in the same location. This helps smooth out the bass coverage throughout the room. You will have some direct-field cancellation – especially where the two wave fronts meet, but this is often the lesser of two evils. Done properly, this can make a room that had several large, noticeable holes in bass coverage significantly less dramatic in its bass tonality shifts. More dense interference should be less noticeable to the untrained listener. Several bass enclosures can be used in a single room to provide fully distributed bass.
For example, is bass enclosure 1 yields spotty, uneven coverage due to room anomalies, add bass enclosure 2 to minimize those problems.
The Acoustimass® enclosure in the FreeSpace® 3 system is an ideal choice for distributed two-way systems in larger or problematic rooms. In rooms that would typically require four satellites and a single bass enclosure, you can effectively use a single FS3 as a single-point bass system. The 70/100V FS3 module can also be used by itself to augment existing full-range systems.
(Source: Bose DesignGuide Application Notes)
News Flash
Take Your Seat, and Enjoy a Three-Dimensional Audio Experience.
Could humanoid droids and vehicles that hover above ground – once limited only to the fantasy worlds of Star Wars — become a reality? On October 11, 2006, the Oregon Museum of Science and Industry (OMSI) presented the West Coast debut of an innovative exhibition, Star Wars: Where Science Meets Imagination. This exhibition was among the many which have taken place at various cities in America, making its debut at the Museum of Science in Boston back in 2005. This exhibit displays costumes and props from all six Star Wars movies alongside real-world technologies and also extensive video interviews with filmmakers, scientists and engineers.
A part of the exhibit was the cockpit of the Millennium Falcon, a full replica of the space ship that was used in the movie Star Wars: Episode IV. This immersive entertainment experience, which takes visitors on a four-minute trip to the edge of the universe, is made even more exciting by using the Bose® 3space™ audio systems. This audio system can make sounds seem to come from almost anywhere around you, and from any distance - from far away to right next to your ear, Bose® 3Space™ systems use small speaker arrays mounted in the seats, speakers positioned around the cockpit, and proprietary signal processing available only from Bose®.
The Bose® 3Space™ audio system in this exhibit uses the principles of psychoacoustics - the science of how people perceive sound - to create the illusion of sounds coming from different angles and at different distances. By varying when and how sounds arrive at the listener's two ears, it can even make sounds appear to come from a direction where there is no speaker.
The Bose® 3Space™ systems also offer exciting 4D effects, like vibrations or wind, to further enhance multimedia experiences - including 3D theater, special exhibits and gaming chairs.The museum schedules to continue this exhibit in various cities across United States till end of 2008.
For more information on this technology log on to www.bose.com
SoundCheck: Sticky Note
Confused about terms like Cycles, Doppler Effect, Reflection, Reverberation, or Resonance? A very helpful website:
http://en.wikipedia.org/wiki/Sound_wave
Did you know?
Humans generally hear sound waves whose frequencies are between 20 and 20,000 Hz. Any value below 20 Hz, sounds are referred to as infrasonic and above 20,000 Hz as ultrasonic. A number of animals produce and use sounds in the infrasonic range. The rumbling vocalizations of elephants were measured to have frequencies as low as 14 Hz which were detectable at a range of 10 km. Ultrasonic sound is commonly used for communication and navigation by bats and dolphins.
Laugh it off…
A doctor and a lawyer were talking at a party. Their conversation was constantly interrupted by people describing their ailments and asking the doctor for free medical advice. After an hour of this, the exasperated doctor asked the lawyer, "What do you do to stop people from asking you for legal advice when you're out of the office?"
"I give it to them," replied the lawyer, "and then I send them a bill."
The doctor was shocked, but agreed to give it a try. The next day, still feeling slightly guilty, the doctor prepared the bills.
When he went to place them in his mailbox, he found a bill from the lawyer.
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