Saturday, April 30, 2016
Updated Flange Fusion Design
After our testing a few days ago, it seemed like the stand with the single column would win out and be used as our final stand design, so I decided to update the flange CAD design to make it more realistic. I incorporated all the screw holes as well as the other cuts and extrudes within the physical (real life) flange. Pictured below is the updated flange.
Thursday, April 28, 2016
Preliminary Testing
Today, we took the Elacs and our speaker stand prototypes to the ExCite Center to perform our initial testing in hopes of detecting which stand was most effective at reducing vibrations and producing an overall "better" sound.
After coordinating weeks in advance with the ExCite Center staff, we were able to gain access to the facility's anechoic chamber. While this may be overkill in this stage of the process (especially considering that our testing is comparative in nature), it will be helpful to have performed it in an neutral environment to make our data much more reliable.
Two tests were performed for each stand. First, the vibration transferred to the bottom of the stand was measured with a seismograph app on an iPhone 5c, which was placed on the bottom of the stands. This numerical data was exported as a .xtml document and will be analyzed further at a later date. The stand that results in the least amount of vibration at the bottom absorbs the most energy from the speaker through movement, indicating that it reduces the quality of the sound reproduced.
The sound quality of the speakers will also be analyzed. Digital recordings were taken of each of the speakers with different songs, each streamed at high quality (~320 kbps). These recordings will be run through computer software to determine various aspects of the frequencies and decibel levels being produced by them.
As the data is analyzed in the coming days, more detail will come with our findings and conclusions about the stand which will be rebuilt in final version for the ultimate deliverable of the project.
The anechoic chamber used for testing can be seen below.
After coordinating weeks in advance with the ExCite Center staff, we were able to gain access to the facility's anechoic chamber. While this may be overkill in this stage of the process (especially considering that our testing is comparative in nature), it will be helpful to have performed it in an neutral environment to make our data much more reliable.
Two tests were performed for each stand. First, the vibration transferred to the bottom of the stand was measured with a seismograph app on an iPhone 5c, which was placed on the bottom of the stands. This numerical data was exported as a .xtml document and will be analyzed further at a later date. The stand that results in the least amount of vibration at the bottom absorbs the most energy from the speaker through movement, indicating that it reduces the quality of the sound reproduced.
The sound quality of the speakers will also be analyzed. Digital recordings were taken of each of the speakers with different songs, each streamed at high quality (~320 kbps). These recordings will be run through computer software to determine various aspects of the frequencies and decibel levels being produced by them.
As the data is analyzed in the coming days, more detail will come with our findings and conclusions about the stand which will be rebuilt in final version for the ultimate deliverable of the project.
The anechoic chamber used for testing can be seen below.
Monday, April 25, 2016
Stand Build
On Saturday, we traveled to my house (within easy driving distance) to execute the prototype build of the project. We chose to leave Drexel's campus for a few reasons. First, having access to a car would allow for easy purchase and transport of necessary bulk materials (PVC, plywood, etc.). Also, it allowed for the flexibility of running out and buying more material easily if unforeseen building issues may have come up. Finally, my house had the necessary woodworking materials and space for construction, without having to work around the schedule of the Machine Shop and the other implicit constraints that would have accompanied that route.
Throughout the past week and half, each group member had been working on a different iteration of the stand design. These were modeled using the Fusion 360 software, which itself was chosen due to its ease of use and for its collaborative/cloud features.
Preliminary CAD Designs
1. Simple Uni-columnar Design - Nick
This design features a single 3" PVC segment as the primary structural component of the stand. PVC Toilet flanges allow for a secure transition from the vertical plane (pipe) to the horizontal plane (top/bottom). The rectangular plates at the top and the bottom will consist of 3/4" plywood. This thicker plywood was chosen because it provides the necessary depth to screw the flanges into the plate without breaking the surface of the wood itself. It will be filled with sand to add weight.
2. Uni-columnar Design with Triangular Base - Blake
This design was the result of several iterations of playing with the advantages and disadvantages of altering the plates from a simple rectangular shape to a variety of other geometric forms. Ultimately, the triangular base was chosen due to its ability to be leveled rather easily on a uneven surfaces. With legs at each of the corners, it functions almost as a small tripod system. The other specifications are similar to Nick's uni-columnar design.
3. Quad-columnar Design - Gabe
Gabe sought to explore the advantages and disadvantages of changing the number of pillars that function as the structural component of the stand. Differing sizes of PVC (2", 1.5", 1") also had to be experimented with, which the CAD was extremely helpful with. Ultimately, after much debate and research, a 4 column, 1.5" PVC design was decided upon due to its ability to provide a strong base with enough volume to weigh down with sand.
Ultimately designs 1 and 3 were chosen as the designs to be prototyped. Design 2 was simply too close to the first design, and didn't offer enough benefits (other than aesthetic) to justify its construction as well.
The Build
Stand 1:
The construction of this stand was relatively easy. The pipe was cut to size (21") with a miter box and attached to the flanges securely with PVC primer and glue. The pipes were filled with sand and 1" wood screws were used to attach the pvc portion to the wood plates, which were cut to exactly hold the speaker. These wood plates were made using a table saw to create a plank of wood to the necessary width (8"), and the other (9") dimension was obtained using a circular saw. All assembled, the stand is 24" tall, bringing the speakers to an optimal height (seated ear level).
Stand 2:
This stand required some more precision in construction. After wresting for many hours over the best method for attaching the PVC columns to the plywood plates (ideally a flange would exist to fit over a 1.5" PVC, but the toilet flange is obviously designed for a specific purpose and only comes in 1 size). After research, we were able to locate and purchase a quick-setting epoxy that would bind PVC to wood, and while not an ideal method, this was by far the best option for accomplishing that task. However, this also required that each of the four columns were exactly the same length, or the flat board would not sit firmly atop it. Therefore, this required care in both measurement and cutting to produce the identical pipe sections, depicted below. Once completed, these pipes were first glued to the bottom plate, then filled with sand, and finally attached to the top plate in a similar fashion. Before transportation back to school, the epoxy was giving an hour to fully cure.
Initial Reactions:
First impressions with the stands have been extremely encouraging. The raising of the speakers off of ground level provides a noticeable improvement in sound, and the stands have proved to be more than acceptable in terms of rigidity and weight. Hopefully, these improvement will be able to quantified during the testing that will occur this week.
Throughout the past week and half, each group member had been working on a different iteration of the stand design. These were modeled using the Fusion 360 software, which itself was chosen due to its ease of use and for its collaborative/cloud features.
Preliminary CAD Designs
1. Simple Uni-columnar Design - Nick
2. Uni-columnar Design with Triangular Base - Blake
This design was the result of several iterations of playing with the advantages and disadvantages of altering the plates from a simple rectangular shape to a variety of other geometric forms. Ultimately, the triangular base was chosen due to its ability to be leveled rather easily on a uneven surfaces. With legs at each of the corners, it functions almost as a small tripod system. The other specifications are similar to Nick's uni-columnar design.
3. Quad-columnar Design - Gabe
Gabe sought to explore the advantages and disadvantages of changing the number of pillars that function as the structural component of the stand. Differing sizes of PVC (2", 1.5", 1") also had to be experimented with, which the CAD was extremely helpful with. Ultimately, after much debate and research, a 4 column, 1.5" PVC design was decided upon due to its ability to provide a strong base with enough volume to weigh down with sand.
Ultimately designs 1 and 3 were chosen as the designs to be prototyped. Design 2 was simply too close to the first design, and didn't offer enough benefits (other than aesthetic) to justify its construction as well.
The Build
Stand 1:
Stand 2:
This stand required some more precision in construction. After wresting for many hours over the best method for attaching the PVC columns to the plywood plates (ideally a flange would exist to fit over a 1.5" PVC, but the toilet flange is obviously designed for a specific purpose and only comes in 1 size). After research, we were able to locate and purchase a quick-setting epoxy that would bind PVC to wood, and while not an ideal method, this was by far the best option for accomplishing that task. However, this also required that each of the four columns were exactly the same length, or the flat board would not sit firmly atop it. Therefore, this required care in both measurement and cutting to produce the identical pipe sections, depicted below. Once completed, these pipes were first glued to the bottom plate, then filled with sand, and finally attached to the top plate in a similar fashion. Before transportation back to school, the epoxy was giving an hour to fully cure.
Initial Reactions:
First impressions with the stands have been extremely encouraging. The raising of the speakers off of ground level provides a noticeable improvement in sound, and the stands have proved to be more than acceptable in terms of rigidity and weight. Hopefully, these improvement will be able to quantified during the testing that will occur this week.
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