Problem Overview: The problem with many high quality speaker cabinets is that they are very expensive. It is very hard to find a cabinet for under a couple hundred dollars that can satisfy ones listening needs, and the design group would like to address this problem by designing a box to put a speaker in that will maximize the output of a single full range speaker.
Design Constraints
·
Price of the material: Some materials may make the speaker sound
better but do not stay under the price range.
·
Manufacturability of the material: A material might be perfect for a speaker
cabinet but be difficult to create the cabinet out of.
·
Availability of materials: Some exotic materials
might not be available, or logical to use in a speaker cabinet.
Previous Solutions
The design of a speaker cabinet affects the sound and quality. While quality is subjective, the more the frequency range overlaps and extends within the normal human hearing range (approximately 20 Hertz to 20 kilo-Hertz) tends to mean higher quality to most individuals.(7) Design incorporates the physical design, location of the driver in the cabinet, and material the cabinet is made. The focus the testing will be the material and not anything else because more than one changing variable can lead to inconclusive results.
The number of materials that can be used is high but a lot can be grouped together to although each individual material in the group still has its’ own individual properties but are similar in nature. Soft materials tend to have lower frequency because of their physical composition. Soft materials do not have the ability to vibrate as well and creates a lack of resonance in the material. Hard materials tend to have high frequencies and create high resonance. Speaker quality adjusts depending on the resonance of the cabinet it is made of.(5)
The number of materials that can be used is high but a lot can be grouped together to although each individual material in the group still has its’ own individual properties but are similar in nature. Soft materials tend to have lower frequency because of their physical composition. Soft materials do not have the ability to vibrate as well and creates a lack of resonance in the material. Hard materials tend to have high frequencies and create high resonance. Speaker quality adjusts depending on the resonance of the cabinet it is made of.(5)
 |
| MDF (8) |
 |
| PVC (9) |
 |
| Plastic (10) |
Soft materials include materials such as hard foam is sometimes seen with other harder materials to help control the resonance. Hard materials such as metal can resonate too much on their own and create a bell like sound. Some materials can contain properties the can be found in hard and soft material. Hard materials tend to be what speakers are made of because of their resonance properties and their ease to work with. Wood and synthetic materials such as plastic, PVC, and medium density fiberboard (MDF) (all shown above to show what the material looks like) tend to be what speakers are made of because of cost and ease of use.
Wood is often used in the form of particle board, plywood, compression board, and other wood that resist or has very little to no wood movement. Solid wood speakers tend to be rated more highly among professional instrumentalist and cabinet makers. Even though the sound tends to be higher rated with solid wood it is harder to work with and does not last as long because of wood movement.
Synthetic materials do not move over time but also do not have the strength of wood nor resonance properties. MDF is made of and similar to wood but tends to be denser and has properties most similar as solid word. Its density in pounds per cubic feet is 48, compared to oak and pine, which is 38 and 29. (2) Plastics are cheaper and used most often used because they are cheaper, but creates a resonance quality different from wood or MDF. The resonance from the plastic tends to be rated lower by professionals.(4)
One of the materials that is rated by professionals to have a high quality for the build of a cabinet is birch plywood. It tends to give a good quality and is easier to work with than some other materials. MDF is as rate to be a good quality that is easy to work with and is cheap for the “quality” that it does provide. The material that is used is based on what the speakers will be used for and the length of time the speakers need to survive with the sound they produce. Most standard individuals would probably notice very little if any between different similar materials.(6)
Design Goal: The goal
of this project is to make a high quality sounding speaker cabinet for a full range cone driver that is cost
effective. A full range speaker is a speaker that is designed to be able to produce a very high range of frequencies, opposed to speaker set ups that use different speakers for different frequencies. Also, a cone driver is the average speaker that works by a magnet that moves the cone, producing sound. This is an example of a full range cone driver.
Since many of the pre-existing solutions either use expensive materials or are based on a particular person's opinions the design group can make a solution unique by researching and testing materials themselves.
Since many of the pre-existing solutions either use expensive materials or are based on a particular person's opinions the design group can make a solution unique by researching and testing materials themselves.
Deliverables: The design group’s main deliverable will be
two speaker cabinets to be compared to one another. Data will be collected from blind studies
that will compare quality of sound of the each cabinet. The blind study will be conducted with peers listening
to one cabinet first and then the other.
They will then state which cabinet they believed sounded better. Furthermore, the design group will test the
frequency distributions of each speaker.
The picture shown above is a 3D model made in a Computer Aid Design (CAD) program to simulate what the proposed design it to look like once finished. The design is completely closed excluding the port used to connect the wire from the speaker to the stereo.
Project Schedule:
Project Schedule:
Project Budget: The
design group will like to design a speaker cabinet that is effective and
affordable. The budget between the
speakers and the materials being used to build the new cabinets will be around
$150 because of the $75 limit to each cabinet, which will be more cost
effective than buying an expensive high quality speaker. For example: Bose speaker cabinets (a well
known, high quality producer of speakers) can be upward of 100 for their most
basic model. Some of Bose's speaker
cabinets can reach thousands.
References
1. HUMAN Speakers. Cabinet building, Assembly, and General Hints. [Online]. Available: http://www.humanspeakers.com/diy/cabinets.htm
2. Lalena Michael. (2012) MDF FAQ [Online]. Available: http://www.diyaudioandvideo.com/FAQ/MDF/#Q3
3. Sony Inc. (2011). The SS-AR1 Story. [Online]. Available: https://dealersource.sel.sony.com/dsweb/p/ar1/
References
1. HUMAN Speakers. Cabinet building, Assembly, and General Hints. [Online]. Available: http://www.humanspeakers.com/diy/cabinets.htm
2. Lalena Michael. (2012) MDF FAQ [Online]. Available: http://www.diyaudioandvideo.com/FAQ/MDF/#Q3
3. Sony Inc. (2011). The SS-AR1 Story. [Online]. Available: https://dealersource.sel.sony.com/dsweb/p/ar1/
4. “Speaker Box Material — Solid Wood or MDF?” Internet:
http://www.woodweb.com/knowledge_base/Speaker_Box_Material__Solid_Wood_or_MDF.html, [April 13, 2012].
5. “Yielding and structural relaxation in soft materials: Evaluation of strain-rate frequency superposition data by the stress decomposition method.” Internet: http://pre.aps.org/abstract/PRE/v84/i5/e051502, [April 13, 2012].
6. “Best Wood for a Speaker Cabinet; The Design World-A Little Rant.” Internet: http://www.woodworkersjournal.com/Ezine/Articles/Best_Wood_for_a_Speaker_Cabinet_The_Design_WorldA_8554.aspx, June 28, 2011 [April 14, 2012]
7. "Sensitivity of Human Ear." Internet: http://hyperphysics.phy-astr.gsu.edu/hbase/sound/earsens.html, [April 21, 2012].
8 "MDF." Internet: http://www.laminatehouse.com/2011/02/24/mdf/, [April 21, 2012].
9. "Plans for Building a PVC Flagpole." Internet: http://www.poorvin.com/roo/flagpole/, [April 20, 2012].
10. "ABS Plastic Sheet Stock for Production." Internet: http://www.archplastics.com/us_california_plastic_distributor/abs_sheet_plastic.html, [April 20, 2012].
11. "Densities of Micillaneous Solids" internet. http://www.engineeringtoolbox.com/density-solids-d_1265.html, [May 22, 2012]
12.“Young Modulus of Elasticity for Metals and Alloys.” Internet: http://www.engineeringtoolbox.com/young-modulus-d_773.html, [May 22, 2012].
13.“Machinist-Materials, Plastics Comparison Table.” Internet: http://www.machinist-materials.com/comparison_table_for_plastics.htm, [May 22, 2012].
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