Subjective Testing

Tonight, the majority of the subjective testing was performed in order to determine whether an average listener was able to discern a positive difference between the sound quality of the Elac speaker when it was placed on the engineered stand.

A set of identical bookshelves was used as a control for the testing. These bookshelves were of standard issue to a dorm room, and their sturdy wood construction simulated an option that many individuals might use in absence of a speaker stand. In addition they measured 24" tall, only a 1.5" difference in height in comparison to height (a negligible height difference that a listener would not be able to detect).

The setup of the experiment was as follows: The subject was seated in a chair 6 feet directly in front of the speakers, facing the operation as to hinder their bias. In addition, they were told to cover their ears initally to prevent them from hearing which surface (the soft rubber or the hard wood) the speakers were placed on to further blind them. They were not told which stand configuration would be played first. They then listened to one track, closed their ears while the speakers were moved to their second configuration. After hearing the second track, they were asked to choose their preference, reasons for their choice, and their degree of certainty in their ability to differentiation (on a 1-10 scale). The following pictures show the setup used in the experiment.

This was performed twice. The first song played was Enya's "Caribbean Blue". This song was chosen on multiple recommendations from sources for its merit as a audio testing song. This is because of its high frequency range, and for its range in instrumentation. The second song played was of the user's choice. Many sources claimed that differentiation is most easily possible in a song that the user is intimately familiar with, as they are more aware of its subtle nuances.

After polling a sample of subjects, the following data was accrued. In total, a minimum of 15 subjects will be polled, but at this majority stage of the experiment the following shows preliminary results:

Sound Data Analysis

Data Compilation

Vibration data recorded form the Seismometer App was exported to Excel, summed, averaged, and compiled into a table. The vibrations on each axis for each recording were summed and then divided by the number of data points. The resulting averages were then converted into readable charts by song to show results visually. Below, we give the charts including the results for "Hotel California" and "Heart of a City (Ain't No Love)".

Meanwhile, the audio recordings were edited. This was done to ensure that any difference between the recordings would be caused solely by the isolation systems used. First, the original tracks were cut to forty seconds. Next the recording in between the start of recording and the start of the track and the time after the end of the recording and when the recording stopped were removed. The recordings were then timeshifted to closely match that of the original track. This was done to eliminate all factors other than a difference in the replicated audio itself that could lead to variable differences between the recordings and thus lead to in correct results.
Once this was completed, each audio file was separated into its own folder, since Similarity must compare two folders. The folders were organized for ease of access.
The audio comparison could now start. Each recording was compared to its respective original track. The percent content, tags, and precision were recorded for each. The data was organized in Microsoft Excel by track and isolation system. An average percent content was taken for each song and the individual recording percent content deviation from the average was made for each recording. The deviation from average for each isolation system in all 3 songs was then summed. The isolation systems will be judged using these numbers. The results for each isolation system are given below.

Isolation Testing Performed

Isolation testing was done at ExCite Center from 2-5 p.m. Vibrations were again measured using the Seismometer App. The two songs which featured heavier bass ("Hotel California" and "Heart of a City") were used for vibration testing. Testing was again done by placing an iPhone 5c on the base of the stand, and recording the vibrations detected while a track was playing. This time, the best design would be indicated by the least amount of vibration measured. This is because the isolation system, as its name indicates, is suppose to mechanically isolate the speaker from the stand. By definition, this meas that the best isolation system would absorb the most vibrational energy, thus giving the lowest vibrational reading at the bottom of the stand.
After this, the audio the speakers produced with each isolation system on the stand was recorded. This was measured with the Audio Recorder app on a Droid Turbo. The experiment was set up with the phone placed on an identical stand, centered on the edge nearest to the speaker of. The nearest edge stand itself was 2' from the forward-facing edge of the stand with the speaker on it, Forty seconds of each song was recorded as a 705 kbps .wav file for each isolation system. This will hopefully give some insight into which isolation system reproduced the audio most accurately.

Week 8 Lab Activitites

This week in lab, we concluded our preparation for the testing, which will be completed this week. The following tasks were completed, both regarding the testing and the project as a whole.

1. Review Project Scope/Timeline: As the term comes to a close (there are only 2 weeks remaining to complete the project), adherence to the project timeline will be crucial to ensure completion.

2. Review of Project Final Draft: The draft of our final report was returned to us and Dr. Knight's critiques were reviewed. This process will help us not only for this project, but for any amount of technical writing which will be done in the future.

3. Discussion of Testing Methods: In order to properly complete the project, there are two rounds of testing that must be performed. First isolation testing must be performed to determine the best orientation of the isolation materials that effectively dissipate external vibrations and remove them from the speaker cabinet. This will be comprised of two separate factors: vibration testing using the Seismometer application and a sound analysis using the Similariy application. High-quality, FLAC versions of 3 songs that have a dynamic range of frequencies will be chosen in an attempt to be able to discern a difference in the resulting sound quality.

Once these values are accrued, the group will be able to choose a final stand/isolation design to use in subjective testing. While this segment may be perhaps less scientific, it is arguably the most important component of the project (as the goal was to produce a stand that improved the listening experience for a consumer at a lower price than those commercially available). A test track that we believe results in a noticeable increase in sound quality will be chosen and shown to our test subjects. In addition, prior research has discerned that often tracks that individuals are most familiar with will be more prone to being analyzed with deep scrutiny. Therefore, we will ask our subjects to choose a song that they know intimately to see whether they were able to discern a difference.

4. Final Report and Presentation Preparation:  While testing needs to still be completed, some discussion on the timing and logistics in preparing the final deliverables was included in the lab activities so we were able to keep the final objectives very much in mind.

More Testing Considerations

We have chosen the tracklist that will be used to test our isolative materials and subjective testing. It is as follows:
     1) Hotel California - Eagles - Hell Freezes Over
     2) Caribbean Blue - Enya - Shepard Moons
     3) Heart of a City (Ain't No Love) - Jay Z - The Blueprint

Lastly, we have chosen the software that will be used to test the isolation system and the audio quality. The software is listed below:
     1) Seismometer App - measures vibrations as a deviation from the mean (mean = no vibrations)
     2) Audio Recorder - records sound files at 705 kbps

Testing Logistics

We contacted Sarah from the ExCITe Center to schedule our final tests, and are waiting for a response. In the next few posts, we will describe our final test method in detail and provide reasoning for each part of it.

Isolation Materials Cut to Size

Today, the group focused on the first step of building the isolation unit, cutting the materials to size. During this, we ran into some trouble neatly cutting the material to size. The sponges proved to be difficult to cut evenly. Ultimately, they ended up being slightly uneven and rough on the edge they were cut from. However, this should have negligible effects, if any, on the performance of the stand. There was also a slight overhang in the foam, about a millimeter at most. This should have no affect of the quality of the stand, as the base is covered fully, and vibration at the base of the speaker will be absorbed just the same. These slight errors only caused cosmetic damage, which can be fixed later in our final isolation unit.

Week 7 Lab Activities

With the final report drafted, the reality of the quickly approaching end of the term has officially sunk in. That said, we have adhered relatively well to the timeline that we set out in the beginning of the term, and are still on schedule to finish the project comfortably within the deadline. It remains paramount that we give the project near-daily attention in order to make this a reality.

This week in lab, we worked on completing several critical tasks that remain in the project. This includes:

1. Review of Project Timeline: The timeline was once again reviewed among the group members in order to confirm our progress. This entailed a review of the remaining tasks at hand (isolation components, testing) and choosing appropriate date ranges when these will be able to take place. 

2. Discussion of Isolation Design: The primary remaining task is the compilation of the various isolation components (rubber, cork, foam, felt) into an effective system for hysteric damping. These components have already been purchased, and all that remains is their assembly. Within the next few days, final methods for this assembly will be finalized, and this progress will be posted  on the blog as necessary.

3. Discussion of Testing Logistics: The other critical task that remains is the objective data acquisition and the subjective listening tests, which will function as our barometer for how well the stands ultimately performed. Possible dates and procedures for doing so were discussed, and these activities will commence in the coming weeks.

4. Start of Project Presentation: The guidelines and rubric for the final presentation were consulted. This presentation was started today (adding the theory, timeline, budget, and other information that is not dependent on future work) in order to save us time and anxiety in the future, which can instead be directed on the actual delivery of the presentation itself.

Final Report Draft

The final report was drafted. It was a compilation of the term's ideas and progress. This allowed us to look upon our progress and determine what we could have done better over the past few weeks, which directly correlated to what we will do in the next few weeks. Primarily, we noticed the variations in our data, which we will deal with in the future by testing more carefully and running more trials to ensure the the trends we saw are valid. However, while reviewing our sources, we did notice several parallels between what we found through testing and what the documents said. This was an encouraging thing to see, as it shows that our results, and therefore our project and how we did it, are valid.

Final Stand Construction

Yesterday, the final stands were constructed, obviously marking a major step in the overall project. The one column stand was chosen as the final design due its rigidity. Many of the same steps were taken to build this stand as were to build the prototype of the one column design. However, extra precautions were taken in order to produce a cleaner final product.

When gluing the PVC to the flanges, a less messy and careful approach was taken in order to get as little spill over of primer onto the outer the surface of the flange. Another precaution that was taken was once the wood plates were sanded we were careful not to set them down anywhere that had things that could chip the surface, such as little pebbles. The last thing we did more carefully was lining up the bottom wood plate with the top wood plate. During the prototype construction, we only realized after we had glued the flanges to the PVC that they needed to be lined up so that the cut-outs matched up on either end of the PVC pipe. This time we ran a line from the top flange to the bottom one, so when we glued them on to the pipe, they would be oriented the same way. Once glued on, the center of the wood plates was found in order to make sure the flange was drilled into the correct position.

As stated earlier, the same methods of construction used in the prototype build were used for the final build. This time around we were much more efficient in our building as we completed the final stand construction in two hours compared to four hours for the prototype pair.

Parts List Assembled

Preparation for tomorrow's build was completed today. Logistics for transportation were ironed out and confirmed among group members. A parts list was compiled so that we will be prepared when we purchase any materials that we don't have left over from our prototype build. In addition, we have the proper measurements of the stands from our CAD designs so that we are able to be as efficient as possible in their construction. More details will come in posts tomorrow and Saturday detailing the results of the build and any problems that we encountered.

Planning for this weekend's drafting of the final report was also accomplished, so that we will be able to juggle the coop process and the responsibilities for this class in an effective manner.

Isolation Materials in Fusion 360

As mentioned previously, during our last lab, I spent some time modeling the different materials we will be testing out as our isolation system. These materials will be tested by themselves as well as stacked in layers. The foam, felt, and cork will be laid across the upper plate, covering it completely. The sponge and rubber feet will be placed in the four corners of the upper plate supporting the speaker like legs. Below are pictures of the modeled isolation materials in Fusion 360.

Cork

Felt

Foam

Rubber Feet

Sponge

Below, a possible arrangement of the isolation materials (1/8" cork placed in-between two sheets of 1/4" foam), is pictured.

Week 6 Lab Activities

With the prototype and preliminary testing phase of our project complete, we spent the duration of today's lab period planning for final push of the term: the construction of the final stands/isolation system and the rounds of subjective and objective testing to demonstrate their effects on the sound quality of the speakers that they support.

The tasks that were completed include:

Planning the Final Stand Build: After our testing on each of the two prototype stands, our vibrational analysis of the stand points to the single column, 3" PVC structure stand as the more rigid of the two prototypes (see previous posts outlining testing procedures and results). Thus, this structural system will be used for the final stand build. We chose a date for this final build (Saturday afternoon, May 7th), and inventoried the materials that we had left over from our first build to determine a list of materials that we still need to buy in preparation for this activity.

Research on Damping Quality of Various Materials: In preparation for the creation of the isolation system that will sit on the top plate of the stand, research was continued on the qualities of an ideal isolative unit. This led to an investigation into the loss factor, dynamic modulus, and other material and mechanical properties that accompany the various materials that we have purchased as potential components of the final designs. Other sources contained math models and other equations that may be helpful in numerically predicting the performance of these materials as damping agents.

Fusion 360: Blake spent much of his time in the lab modeling the different sheets of materials that may be integrated into the isolation system. We will be able to utilize these to model our isolation systems before we physically construct them.

Similarity App: Gabe continued his research into the features of the Similarity PC app that he has downloaded and that we plan to use to analyze the quality of the music produced by the speakers on top of the stand. We are hopeful that this will provide an objective source of data to support any subjective conclusions that we are able to make.

Sound Recording Analysis Software

Several different programs were downloaded and tested to see whether or not they would yield insight in the difference between the original audio files and the recordings. Audiodiff Maker, Similarity, and others were used. All but the first two were quickly proved useless. Audiodiff Maker made an audio file which was the difference between the two programs, but could not align the start of the song in the files, so that the files could not be accurately analyzed. This left Similarity, which claims to compensate for different start times for the tracks. Similarity, upon first test, yielded questionable results. However, this is our best option, so more tests will be run.

Data Analysis

Over the course of the weekend, we have been hard at work analyzing the raw data gathered in the preliminary testing of last week. Essentially we were out to determine which of the stand structures was the most rigid and stable. To do so, we used the Seismometer 6th iOS application, which recorded vibrations at the bottom of the base. The thought process behind the experiment was that the more rigid stand would effectively transport the vibrational motion from the stand to the base. The least rigid would get lower vibration readings, indicating that the stand absorbs energy, decreasing the quality of sound reproduced. Once the more rigid stand is determined (providing the optimal structural base) an effective isolation system comprised of a combination of foam, rubber, cork , or felt would dissipate the vibrations exuded by the speaker at their origin (the point of contact between the speaker and stand), producing the highest quality sound overall.

The Seismometer app produced its data graphically on the app, but allowed for it to be exported in an Excel file numerically. The file was formatted as seen below:

Where the vibrations have been deconstructed into their x,y, and z axis components. Each of these numbers represent the degree of deviation from the base reading (no vibration). These deviations for each of the axes over a 25 second period of a song were summed to determine the gross amount of deviations. The stand that yielded the highest gross deviations was also the stand that was most effective at transmitting the vibrations from the top plate of the stand to the bottom, a result of a rigidly constructed stand structure.

Our results are as follows:

Stand 1:

Stand 2:

Clearly, our results point to stand 1 being the most rigid stand, and therefore the best choice for the structure of the final stand. We as a group will choose a mutually acceptable date to construct the final stand, which will allow us to move on to the construction and testing of the isolation components, which will be able to be tested subjectively (in a room setting with a group of volunteer listeners) and numerically using both the Seismometer app once again as well as sound analysis applications which have already been downloaded. More information to come about logistics for the final stand build, the thought process behind the isolation system, and the applications that will be used for the final testing.

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.

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.

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.

Stand Prototypes Built

After a thoroughly exhausting day of working on the project, a pair of speaker stands were constructed, functioning as the working prototypes for the testing that will occur throughout the week.

Due to the lateness of the hour and the amount of combined fatigue from group members, a detailed post with the detailed record of the day's activities, along with the Fusion 360 CAD models that were used as the basis for the build.

Below is a picture of the two different stands supporting the speakers.

Sound Analysis Software

For some time, we have been considering how to test the stand quantitatively. We decided that we will record the speaker and then compare the recording to the original audio file and find a way to calculate the difference between the two files. This left the question of what software we could use to do this analysis with. After some research, I identified several programs that may be able to compare two audio files and give a numerical representation of the difference between the two. Among them are Sonic Visualiser, Praat, Audio DiffMaker, and musicg. All of these programs have been downloaded and will be experimented with to see if they can produce the desired results, and of them, which can produce the best results.

Week 4 Lab Activities

During our time today in the innovation studios, a variety of issues were discussed in detail, including:

1. Logistics for this weekend's build: An mutually acceptable time was chosen for travelling to purchase the materials and build the stand and isolation system prototypes.
2. Parts List: A materials list was also created in order than the trip to the hardware store might be as efficient as possible. This also ensured that the project stayed within budget.
3. Iterations of stand design: After the logistics were completed, much time was spent discussing the progress of each of the stand designs, and of the ideas related to the isolation system which will decouple the speaker from the stand, hopefully producing a much more agreeable sound.
1. Designs chosen include a single-column, 3" PVC structure with plates on the top and bottom, and a multi-column, 2" PVC structure, again with plates on the top and the bottom. We are still determining the exact number and orientation (2 in a line, 4 in the corners) of the PVC, and this decision will obviously come in the next few days before the build itself. Connections to the isolation system also still need to be ironed out.
2. Isolation component debate: Much of the class was also spent determining the different isolation systems that will be utilized to decouple the speaker itself from the stand in order that the stand won't interfere with performance. Research included an analysis of the resonance of different materials and especially the composition of industry-standard soundproofing systems which are advertise to decouple the sound from the surrounding environments. This research will be continued and will inspire the systems that we choose to actually construct (albeit with a DIY, low budget perspective).

As each of the designs are finalized and decided upon, updates to the blog will reflect this progress.

Speakers

Blake brought the ELAC B5's back on Sunday 4/17/2016. These were tested on the same day by playing a variety of standard-quality music while all members of the group tried to listen to the music and determine if there was a significant improvement in the quality of sound. Ultimately, it was decided that the quality of the speakers was more than sufficient. In the future, we plan to listen to high-fidelity music tracks to see if the speakers are capable of producing a noticeable difference.

Loudspeaker Arrival

Our speakers have arrived! Today I went home to get them and set them up. I tested them out and they sound great. I'm quite pleased with our purchase. I'm excited to take them back to school tomorrow and show them to the rest of the group. I'm sure they will also be happy with the quality of the speakers. Below is a picture of the speakers hooked up to a receiver that will be used to complete our project.

Toilet Flange Discovery

Throughout the design process, one of primary issues has been in navigating the transition from the vertical plane (the column) to the horizontal plane (the top and bottom plates) in a secure manner. This joint was crucial to maintaining the structural integrity of the stand and preserving the sound quality of the speaker while sitting on the stand.

The apparent solution to this dilemma came in the form of an unlikely piece of hardware: the PVC toilet flange. These flanges are able to fit snugly over top of a 3" PVC (or inside of a 4"PVC), and include holes on the structure where bolts or screws can be inserted to couple a plate to the structure. With the application of PVC primer and glue, this flange should effectively provide a workable surface onto which plates can  be attached firmly. 

Below are images of the flange itself, and how it interacts with a 3" PVC pipe section:

Iterations of Stand Design

After hours of deliberation both in lab and outside of class, and after reflecting on the various possibilities for stand structure design, we have decided on three different iterations to model in Fusion360. One will consist of a tripod base for easy leveling for different surfaces, while the other has a more standard rectangular base. These first two will have one 3" PVC functioning as the main structural component. The third design will consist of 3 smaller (2" diameter) PVC, arranged in a triangular pattern to function as the structure, with rectangular plates on the base.

Each team member will be in charge of creating one of these CAD models, in hopes that they will be finished by the weekend. We may also use Fusion360's built-in structure/stress analysis to test the dynamics acting on each of the designs. Overall, we hope to have a final decision on the stand design by this weekend, as the following weeking (4/23) is the date that we will be constructing the stands themselves.

Other issues to iron out are the scale/materials of the prototypes, and also a final deliberation on the material used for the plates at the top and the bottom of the stand (essentially determining whether steel is the best/most appropriate option for base material). Again, we hope to have these issues ironed out by the start of lab next week so that we can accurately formulate a list of necessary parts/materials needed when we visit a hardware store prior to construction.

Loudspeaker Purchase

We have officially purchased our loudspeakers that we will be using for testing. We decided to go with the lesser known ELAC B5's over the Bose 201's. After hours of research, we couldn't find anyone who was not thrilled with their purchase. The knowledge of customer satisfaction, the award they won last year, and the fact that they were designed by Andrew Jones put these speakers at the top of our list. They should arrive this week, so we will be able to begin playing with them and see how they sound.

Stand Research - Existing Designs

In an attempt to gain design inspiration and continue to gain familiarity with the speaker/speaker stand industry, I visited WorldWide Stereo, a dealer in high quality speaker and home theater systems and entertainment furniture. This visit provided invaluable knowledge regarding the design, materials, and properties of industry-standard stands.

Even though many speaker stand designs varied in their aesthetic qualities, they did have many similarities in various features. These included:

1. Similar height (stands stood 24 inches on average)
2. Rigidity - stiff structure, with bolts on the joints
3. Weight - gained through the choice of material (steel)
4. Stability - rubber stops or spikes ensured a firm connection with the floor
5. Isolation - rubber, foam, or cork was used on the surface on which the speaker stood

These factors will be heeded in the design of our custom speaker stand, which will begin this week.

Below are images of some speaker stands whose designs appeared both viable and effective, and could be used for inspiration in our project.

Research on Spikes

     So far, research has been done on various methods of isolating the speaker. The most shocking thing that was found was the number of conflicting designs and viewpoints on the competency of the designs. The biggest of these was the application of spikes present in many of the designs. Many designers claim that this will vastly improve the quality of the sound. However, the online magazine Audioholics says that at best they "seem[s] to have a noticeable effect", though depending on the situation they are used in, research "indicate[s]d that cones are of doubtful use if the intention is to stop vibrations passing from the speaker to the stand." Based on this disagreement, a decision has been made that spikes will not be used in any tests. Pictured below are stands with different spike setups incorporated on them.

Loudspeakers

In order to complete our project, a set of quality loudspeakers must be purchased. Our group has gone through many different speakers and has now narrowed it down to two different speakers. There speakers are the Bose 201's and the ELAC B5's.

The comparisons we have done between them left us with the following. The speakers are about $10 different in price, with B5's being the pricier. The B5's are 8.8" x 7.9" x 12.8" and weigh 12 pounds. They have a 5.25" woofer. The 201's are 13" x 8" x 8" and weigh 22.4 pounds. They have a 6.5" woofer.

Our first instinct tells us to go with the Bose speakers just because Bose is such a reputable company and ELAC is relatively unheard of. My brother has a pair of Bose 301's and they sound terrific so I am assuming the 201's are also very nice. However, the B5's won the 2015 Absolute Sound Product of the Year and they are designed by famous speaker designer, Andrew Jones.

Hopefully we can make a final decision soon and purchase our speakers, putting us a step further in our project.

Detailed Timeline Established

One of the primary concerns of this free design project is the amount of time (or lack thereof between the myriad of other time responsibilities) that will be available to commit to the various tasks required for its completion. Therefore, as the group's leader, I find that one of my most critical job is making sure that each of us individually and together as a group are able to stay on schedule.

Thus, the first step in fulfilling this responsibility is actually creating a detailed timeline in the first place. A vague version of this was necessary for the Design Proposal submitted earlier in the week, so the detailed plan of action established during our lab period is an elaboration on this thinking, including detailed tasks and exact dates that these tasks will need to be accomplished.

The schedule was created using the collaborative software offered by TeamUp, giving each group member the ability to access and modify the calendar as he so chooses. This will be critical in making sure we as a group are on the same page and keeping this project's timeline in mind amidst the other deadlines that we have in our individual class/personal schedules.

A link to this timeline is posted below:

https://teamup.com/ks1aa8a05a1e2354ab

Decision Matrix

Roles and Responsibilities

Click on the link if you would like to view the member's team roles and responsibilities.

Plan of Action

     This problem will be addressed in several steps. The first, research, will consist of gaining a physical understanding of sound waves and isolation stands as well as previous designs of stands. This will be followed up with securing a high-fidelity speaker for testing. Afterwards, several deigns will be brainstormed, analyzed, and the best design will be selected. At this point, a prototype of the stand will be made and then tested. After this, a report on the process and results of the project will be made.

Problem Statement

Speaker stands preserve the quality of sound a speaker produces. However, quality speaker stands are quite expensive.Speaker stands function by isolating the speaker to reduce the dissipation of the speaker's vibrations, increasing the quality of sound replication. As such, the objective of this project is to design and fabricate an inexpensive quality speaker stand that features an isolating element.