Hi All,
I’m pleased to announce that the “Sound DIY Club” will be sponsoring “The Puget Sound DIY Speaker contest” this year. It will be hosted by the Pacific Northwest Audio Society (PNWAS), at its current meeting location in the lower level of the
Kirkland Congregational Church
106 5th Ave,
Kirkland, WA 98033
The Contest is scheduled for Saturday, October 5th, with the doors opening for registration at about 11:00 AM and the general public at approximately 11:30 to 11:45. We will attempt to start the judging at 12:00 noon.
More details follow:
What Will Happen?
The Contest will be held at the Kirkland Congregational Church, 106 5th Ave, Kirkland, WA 98033.
Doors open at 11:00 a.m., and judging will begin around 12:00 noon. We may be flexible on start time if a contestant is traveling some distance and may be arriving later than the start time; please let us know in advance so we can schedule accordingly.
Entries
There will be two "classes" of entries: original DIY designs and kits. We realize that a lot of effort, experience, skill and sometimes luck are needed to come up with a successful design. Many accomplished designers learned their craft by starting with kits of one sort or another and subsequently progressed toward original designs. For others, the lack of time or experience makes a kit a means towards better, affordable sound.
Also, if you can bring speaker stands, that would be helpful.
A Kit is defined as...
...Any pre-designed or published design (publication includes the Internet) that is the product of another person. This may be plans, parts, kit, or both plus cabinets, etc. Any major deviation from the plans may at some point constitute an original design -- however, a club appointed technical committee will have the final determination if this problem presents itself. All kits must have been offered to and available to the general public at some time. We rely on the integrity of the contestant!
The kit class is broken down by cost per pair and excludes the cost of the cabinet and finish. The breakdown for kits is as follows:
$0-$175/pair
$176-$325/pair
$326+/pair
Original Designs:
The breakdown is as follows:
One way ----under $75/over $75
Two way ----under $200/over $200
Three way -- under $300/over $300
Unlimited ---- no limit
NOTE: This is for drivers and crossover parts only; cabinet material and finish are not included. We again rely on the contestants' integrity. Your uncle who owns the HiFi Emporium cannot give you a special deal that isn't or hasn't been available to the general public. Nuff Said!
The speakers will be driven by the system supplied by the club. Don't bring your own Megawatt Hyper Triode Amp -- we're not going to use it. To keep it simple, we are not going to allow biamping or plate amps for a bass module.
The entry fee is $10 to register at the door. If you have any questions please post on one of the forums with an official thread on the contest, like this one. Also, it would help us a great deal if you'd let us know or think you're coming.
Judging
The judging will be by a panel of judges in a special room set aside for this. We will have three judges, which in turn plays his personal pre-selected musical selections (2-3 minutes max.) while sitting in the "sweet spot." Each contestant is allowed to specify general guidelines to set-up, that is, distance apart, toe-in, although corner loaded speakers will need to provide their own artificial corners. Remember that the judges will be sitting side by side so that should be taken into consideration.
We intend that judging will be totally blind -- this means that a curtain is utilized to ensure that sound, and not appearance, will be the sole criteria. All speakers will have the loudness adjusted to the same level before judging begins. Set-up of speakers will be by a club crew using notes taken at time of entry. Each judge will be issued a standard evaluation form prior to each session, and will rate each entry by assigning points, after which the form is collected by the Technical Committee member assigned to monitoring the judging (and setting SPL levels prior to each evaluation of an entry, etc). The forms are then scored by the Contest Director, or his designee for total points. After the final entry is judged, the points earned are assigned within each category to determine ranking within that class. The total overall points regardless of category or class will determine Best Sound of Show.
Other Stuff:
General admission of the public is free. We hope to have a garage sale/swap meet type offering for those who wish to sell or buy audio gear for free. However, the owners are responsible for their gear, etc. Don't expect to drop off stuff and return at the end of the day to pick up the money. (Please advise in advance if you wish to sell items).
We are going to let the attendees help out by voting for the Best Craftsmanship, Most Unusual, Most Creative Use of Material (Bondo, duct tape, silly putty, etc.).
Awards:
Each entry will receive a certificate of participation and a print out of the entry's frequency response measured by a qualified expert designated by the Contest Director or head of the Technical Committee. Additional certificates will be awarded to class winners, as well as 2nd place .
Finally a "Best Sound of Show" certificate will be presented to the overall winner. All winners of their respective DIY class are eligible for this. Please note that "kit" speakers aren't eligible for the Best Sound of Show.
Unless overruled by the Technical Committee for violation of the rules, the decision (total points) of the judges is final.
Best Regards,
TerryO
I’m pleased to announce that the “Sound DIY Club” will be sponsoring “The Puget Sound DIY Speaker contest” this year. It will be hosted by the Pacific Northwest Audio Society (PNWAS), at its current meeting location in the lower level of the
Kirkland Congregational Church
106 5th Ave,
Kirkland, WA 98033
The Contest is scheduled for Saturday, October 5th, with the doors opening for registration at about 11:00 AM and the general public at approximately 11:30 to 11:45. We will attempt to start the judging at 12:00 noon.
More details follow:
What Will Happen?
The Contest will be held at the Kirkland Congregational Church, 106 5th Ave, Kirkland, WA 98033.
Doors open at 11:00 a.m., and judging will begin around 12:00 noon. We may be flexible on start time if a contestant is traveling some distance and may be arriving later than the start time; please let us know in advance so we can schedule accordingly.
Entries
There will be two "classes" of entries: original DIY designs and kits. We realize that a lot of effort, experience, skill and sometimes luck are needed to come up with a successful design. Many accomplished designers learned their craft by starting with kits of one sort or another and subsequently progressed toward original designs. For others, the lack of time or experience makes a kit a means towards better, affordable sound.
Also, if you can bring speaker stands, that would be helpful.
A Kit is defined as...
...Any pre-designed or published design (publication includes the Internet) that is the product of another person. This may be plans, parts, kit, or both plus cabinets, etc. Any major deviation from the plans may at some point constitute an original design -- however, a club appointed technical committee will have the final determination if this problem presents itself. All kits must have been offered to and available to the general public at some time. We rely on the integrity of the contestant!
The kit class is broken down by cost per pair and excludes the cost of the cabinet and finish. The breakdown for kits is as follows:
$0-$175/pair
$176-$325/pair
$326+/pair
Original Designs:
The breakdown is as follows:
One way ----under $75/over $75
Two way ----under $200/over $200
Three way -- under $300/over $300
Unlimited ---- no limit
NOTE: This is for drivers and crossover parts only; cabinet material and finish are not included. We again rely on the contestants' integrity. Your uncle who owns the HiFi Emporium cannot give you a special deal that isn't or hasn't been available to the general public. Nuff Said!
The speakers will be driven by the system supplied by the club. Don't bring your own Megawatt Hyper Triode Amp -- we're not going to use it. To keep it simple, we are not going to allow biamping or plate amps for a bass module.
The entry fee is $10 to register at the door. If you have any questions please post on one of the forums with an official thread on the contest, like this one. Also, it would help us a great deal if you'd let us know or think you're coming.
Judging
The judging will be by a panel of judges in a special room set aside for this. We will have three judges, which in turn plays his personal pre-selected musical selections (2-3 minutes max.) while sitting in the "sweet spot." Each contestant is allowed to specify general guidelines to set-up, that is, distance apart, toe-in, although corner loaded speakers will need to provide their own artificial corners. Remember that the judges will be sitting side by side so that should be taken into consideration.
We intend that judging will be totally blind -- this means that a curtain is utilized to ensure that sound, and not appearance, will be the sole criteria. All speakers will have the loudness adjusted to the same level before judging begins. Set-up of speakers will be by a club crew using notes taken at time of entry. Each judge will be issued a standard evaluation form prior to each session, and will rate each entry by assigning points, after which the form is collected by the Technical Committee member assigned to monitoring the judging (and setting SPL levels prior to each evaluation of an entry, etc). The forms are then scored by the Contest Director, or his designee for total points. After the final entry is judged, the points earned are assigned within each category to determine ranking within that class. The total overall points regardless of category or class will determine Best Sound of Show.
Other Stuff:
General admission of the public is free. We hope to have a garage sale/swap meet type offering for those who wish to sell or buy audio gear for free. However, the owners are responsible for their gear, etc. Don't expect to drop off stuff and return at the end of the day to pick up the money. (Please advise in advance if you wish to sell items).
We are going to let the attendees help out by voting for the Best Craftsmanship, Most Unusual, Most Creative Use of Material (Bondo, duct tape, silly putty, etc.).
Awards:
Each entry will receive a certificate of participation and a print out of the entry's frequency response measured by a qualified expert designated by the Contest Director or head of the Technical Committee. Additional certificates will be awarded to class winners, as well as 2nd place .
Finally a "Best Sound of Show" certificate will be presented to the overall winner. All winners of their respective DIY class are eligible for this. Please note that "kit" speakers aren't eligible for the Best Sound of Show.
Unless overruled by the Technical Committee for violation of the rules, the decision (total points) of the judges is final.
Best Regards,
TerryO
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Now located smack dab in the right forum as requested by the honourable member.
Oh, and a big hello to Terry as well.
Oct. 5th is just 4 weeks away!
Finish up your diy speakers and bring 'em in.
I've got a pair or two to enter myself.
Finish up your diy speakers and bring 'em in.
I've got a pair or two to enter myself.
Everytime I drive by Kirkland I keep looking for the Toilet Paper Factory and the fine wineries of Chateaux de Kirkland.
I'm waiting for the Kirkland Signature monitor and planar speakers.
I'm waiting for the Kirkland Signature monitor and planar speakers.
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Our $$$ categories do not reflect inflation! I know at least one build that should/will be coming to the contest, the cost of which would be more accurately reflected by adding a zero to the highest category, and not be off by much! The guilty party knows of which I speak! Maybe there is more than one pair like this? Anyway the most coveted(?) award goes to "Best in show" for which there is no $ limit.
I will bring 2 or three different pairs that grew out in the last few years; one pair of which uses many free and inexpensive parts gathered over the past many years, and cost about $300. These sound great to me---but then how many builders don't like their own builds???
I will bring a 3-way pair, with passive radiators, that, while repurposing nice 1976 walnut cabinets and other wood I had on hand, uses affordable new drivers and decent (not audiophile fancy) crossover parts. Still the cost must have been $600 or $700.
Dave R shared a photo here of his contending 3-ways here, who's performance rivals or exceeds the majority of home speakers that most mortal beings can afford. These speakers actually were built on a budget, but the mostly-vintage drivers are really good. Also, Dave is our notable authority in passive series crossover design.
I have been involved in the contest for about 15 years (it happens every two years, minus the pandemic) and it has always been a fun an welcoming place for all, including newbies.
As indicated above it does not accommodate "active" designs at this point, but if you are an advocate of such technologies, lets us know!
I will bring 2 or three different pairs that grew out in the last few years; one pair of which uses many free and inexpensive parts gathered over the past many years, and cost about $300. These sound great to me---but then how many builders don't like their own builds???
I will bring a 3-way pair, with passive radiators, that, while repurposing nice 1976 walnut cabinets and other wood I had on hand, uses affordable new drivers and decent (not audiophile fancy) crossover parts. Still the cost must have been $600 or $700.
Dave R shared a photo here of his contending 3-ways here, who's performance rivals or exceeds the majority of home speakers that most mortal beings can afford. These speakers actually were built on a budget, but the mostly-vintage drivers are really good. Also, Dave is our notable authority in passive series crossover design.
I have been involved in the contest for about 15 years (it happens every two years, minus the pandemic) and it has always been a fun an welcoming place for all, including newbies.
As indicated above it does not accommodate "active" designs at this point, but if you are an advocate of such technologies, lets us know!
Spending thousands on drivers. Who would do such a thing? The first of four woofer boxes is taking shape. Baltic Birch plywood, 12 mm. The back panel resonance came in lower than predicted. It rings at 250Hz before any braces have been added. Not the 450 Hz I was hoping for. Apparently the edges flex and are not as constrained as the calculator assumes. Blocks in the corners and some braces next. I want to get to 900 Hz or so with the woofer playing up to 425Hz.
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Suggestion: “Stereo Pair under 10 liters Internal volume” ---or something like this.
This comment is more oriented towards future contest years, as it is too late, on a few levels, to change the rules, categories and metrics this year.
The categories listed in the first post, those that have been standard for so many years, have been based on crossover sections (1-way 2way, 3-way) and cost. But another huge constraint on design, and one that has some domestic considerations, is speaker (box) size.
I started thinking about this while listening to a DIY pair of mine that “sound great for their size”---which when commented on by others, has largely amounted to “so much bass for their size!”. There have been a number of great sounding small speakers produced by club members, and visitors that have participated in the contest, that mostly just lacked deep bass.
So maybe a category like: “Stereo Pair under 10 liters Internal volume”, or some such. These could use of any number of drivers, be sealed or ported, etc---but not use auxiliary woofers that are not contained in the enclosure. We can already use “stacked” arrangements where separate boxes house the woofers vs the other drivers.
I guess that we already do something like this in the awarding process, to recognize builds that don't fit neatly into existing categories. I think I once got a recognition for “best open baffle” when there were not other OB speakers entered in the contest---sorry if I am forgetting other's entries for that year! So in a way this amounted to a “participation” award---but was significant to me---I still remember it.
Small speakers are a very important segment of the commercial market, because they are important in peoples listening lives and budgets, including DIY budgets. Also mini-monitors are very important in modern recording environments.
This comment is more oriented towards future contest years, as it is too late, on a few levels, to change the rules, categories and metrics this year.
The categories listed in the first post, those that have been standard for so many years, have been based on crossover sections (1-way 2way, 3-way) and cost. But another huge constraint on design, and one that has some domestic considerations, is speaker (box) size.
I started thinking about this while listening to a DIY pair of mine that “sound great for their size”---which when commented on by others, has largely amounted to “so much bass for their size!”. There have been a number of great sounding small speakers produced by club members, and visitors that have participated in the contest, that mostly just lacked deep bass.
So maybe a category like: “Stereo Pair under 10 liters Internal volume”, or some such. These could use of any number of drivers, be sealed or ported, etc---but not use auxiliary woofers that are not contained in the enclosure. We can already use “stacked” arrangements where separate boxes house the woofers vs the other drivers.
I guess that we already do something like this in the awarding process, to recognize builds that don't fit neatly into existing categories. I think I once got a recognition for “best open baffle” when there were not other OB speakers entered in the contest---sorry if I am forgetting other's entries for that year! So in a way this amounted to a “participation” award---but was significant to me---I still remember it.
Small speakers are a very important segment of the commercial market, because they are important in peoples listening lives and budgets, including DIY budgets. Also mini-monitors are very important in modern recording environments.
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Howard's idea with the 10 liter or under category is great. It would promote more book shelf sized speakers that many people like to build.
I like to design using new and readily available drivers so I can built another pair easily if needed. Individual middle of the road drivers are often $100 each, so I can see adjusting the price levels in the future. Sure there are bargain bin drivers out there for less. I don't like spending the significant time that is required to create a design with no longer available, highly discounted drivers as after a few months no one else can get those drivers and use that design. This assumes that someday I'll design something good enough that someone else will want to build it. Ha
My four 17" x 17" x 9" woofer boxes are coming together. First I need to tame the resonances and then I need to figure out how to build a baffle to house the midranges and tweeters.
I like to design using new and readily available drivers so I can built another pair easily if needed. Individual middle of the road drivers are often $100 each, so I can see adjusting the price levels in the future. Sure there are bargain bin drivers out there for less. I don't like spending the significant time that is required to create a design with no longer available, highly discounted drivers as after a few months no one else can get those drivers and use that design. This assumes that someday I'll design something good enough that someone else will want to build it. Ha
My four 17" x 17" x 9" woofer boxes are coming together. First I need to tame the resonances and then I need to figure out how to build a baffle to house the midranges and tweeters.
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Add this to the announcement:
For anyone who has speakers to enter - bring some speaker stands if you can.
For anyone who has speakers to enter - bring some speaker stands if you can.
Constants.... ay! You should create a named constant to hold that 2.54, something like Inches_to_mm = 25.4. It makes the code much more readable. We avoid "magic numbers" when we peer review code.
What is 12.3?
Another comment: since you seem to have some measurements in metric and others in standard, you might want to include the dimensions in all variable names... such as Bx_mm... you already have done such for bIn.
I assume that's what 25.4 and 2.54 are huh?
I assume floating numbers...
Seems to me that a full description of the (full) system intended for testing needs to be described.
tonyEE: Oops, That code got into a picture. Yeah, the code review isn't until next month.
brianco:
The design goals are:
108 dB max SPL at one meter
40 Hz and up.-3dB at or below 40 Hz -10 dB at 27 Hz
Omni-directional radiation pattern
Speaker impedance that won't blow up the club amp.
Each speaker breaks up into 3 modules that weight less than 20 lbs. each.
I sort of design as I build, so the configuration is evolving as we approach Oct 5th. The original idea is a three way monolith with back to back 10" woofers, 3" dome midranges and 1" dome tweeters. I had to add two 12 inch passive radiators, as sealed woofers wouldn't provide the deep bass without EQ, which isn't allowed at the contest. Here a drawing from boxsim of the original concept without the passive radiators. I'm building it as three modules that stack. Two woofer boxes stacked vertically and a box on top of those with the mids and tweeters. The passive radiators messed things up a bit, so the woofers will be offset vertically, each with a passive radiator behind it.
Cabinet and driver placement.
Horizontal radiation pattern vs frequency. It's nearly omni-directional up to about 6 kHz.
brianco:
The design goals are:
108 dB max SPL at one meter
40 Hz and up.-3dB at or below 40 Hz -10 dB at 27 Hz
Omni-directional radiation pattern
Speaker impedance that won't blow up the club amp.
Each speaker breaks up into 3 modules that weight less than 20 lbs. each.
I sort of design as I build, so the configuration is evolving as we approach Oct 5th. The original idea is a three way monolith with back to back 10" woofers, 3" dome midranges and 1" dome tweeters. I had to add two 12 inch passive radiators, as sealed woofers wouldn't provide the deep bass without EQ, which isn't allowed at the contest. Here a drawing from boxsim of the original concept without the passive radiators. I'm building it as three modules that stack. Two woofer boxes stacked vertically and a box on top of those with the mids and tweeters. The passive radiators messed things up a bit, so the woofers will be offset vertically, each with a passive radiator behind it.
Cabinet and driver placement.
Horizontal radiation pattern vs frequency. It's nearly omni-directional up to about 6 kHz.
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It would be most fun if you could do it so the user could hook it up omni or dipole.
I once played -for 3 years- with two pairs of minimonitors, stacked on top of each other with the tweeters and woofers in a pseudo d'Appolito configuration. I used two stereo amps to drive them. In this shape, I could set it up as a normal forward radiator, or rotate the top and go dipole or omnipole by changing the phase of the wiring...
It was really fun and taught me a lot about speaker placement.
I once played -for 3 years- with two pairs of minimonitors, stacked on top of each other with the tweeters and woofers in a pseudo d'Appolito configuration. I used two stereo amps to drive them. In this shape, I could set it up as a normal forward radiator, or rotate the top and go dipole or omnipole by changing the phase of the wiring...
It was really fun and taught me a lot about speaker placement.
@olsond3
What I mean in the above is what is the amplifier and source to be used by all. Are the amp(s) tube or solid state and what is the power into 8R & 4R - is the signal digital or analogue? Without the fullest info on the chain it would seem to me just a matter of chance as to how the submitted speakers will perform.
@brianco
The club's amplifier has plenty of headroom for even inefficient speakers and they have analog output. Only passive speakers are allowed so that the same amp is used to drive each speaker entry.
A cd with judges' tracks also contains a pink noise track. Once the judges decide on the appropriate listening level of the music tracks, the pink noise track is used to determine the dB level using an SPL meter. (The club speakers are used for this level-setting.) Each speaker entry is then driven at the same dB level with the same amp.
To prevent any biases from visual cues, the speakers are hidden behind a black curtain (can't see through it) which is acoustically transparent. Except for the folks who set up each speaker entry (behind the curtain), only the judges are allowed in the listening room. This prevents the judges from being biased by any attendee comments or opinions about the entries.
The judges have a score sheet to rate different aspects of the speakers based only on what they hear.
All of this is set up to provide a fair playing field without biases inasmuch as possible. Same room, same seating positions, same equipment, same music tracks, same listening level, same judges, same score sheet, and free from visual or auditory biases. The intent is that the speaker is the only variable.
The club's amplifier has plenty of headroom for even inefficient speakers and they have analog output. Only passive speakers are allowed so that the same amp is used to drive each speaker entry.
A cd with judges' tracks also contains a pink noise track. Once the judges decide on the appropriate listening level of the music tracks, the pink noise track is used to determine the dB level using an SPL meter. (The club speakers are used for this level-setting.) Each speaker entry is then driven at the same dB level with the same amp.
To prevent any biases from visual cues, the speakers are hidden behind a black curtain (can't see through it) which is acoustically transparent. Except for the folks who set up each speaker entry (behind the curtain), only the judges are allowed in the listening room. This prevents the judges from being biased by any attendee comments or opinions about the entries.
The judges have a score sheet to rate different aspects of the speakers based only on what they hear.
All of this is set up to provide a fair playing field without biases inasmuch as possible. Same room, same seating positions, same equipment, same music tracks, same listening level, same judges, same score sheet, and free from visual or auditory biases. The intent is that the speaker is the only variable.
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