One more SPUD build "They call me Tater"

[Pete H]

OK, after about a year it was time to build a SPUD even though I'm suppose to be building the final kitchen cabinets I told her that I needed to test the set up prior to cutting up $80 sheets of cherry plywood so instead I cut up $50 sheets of baltic birch.

I thought I had a set of plans for the spud that consisted of all the measurements, but not the case; so after printing out what I had and sifting through e-mails where Rudy81 gave me some of his measurements from his build, I decided to get er done. Last night after building a new landing table for the saw I ripped all the main pieces(didn't take any pictures of ripping plywood) and got started.

After reading other build threads on this I decided that taking the time to build a template would be the smartest way to go; I apologize for the pic quality, they're off the phone and it was really dusty in the shop.

Note that everything needed is here; speed squares, t squares, tape, pencil, pen, sharpie, plans, calculator and super cold Coors Light.

[Pete H]

I used a piece of 1/4" plywood for the template so I could move it around with ease and store it away for future builds. Once everything was laid out I decided to mark out the critical measurements right on the template so I didn't have to do any thinking down the road to cut pieces. I will note that after calculating everything out from the information I had, my final dimensions varied slightly from some other builds, but after checking all the measurements 3x as well as the math I am confident that the nominal differences will not amount to anything more than the slight variations on marking or making a cut that occur and the horn progresses as I believe it should.

[Panacea Engineering]

Pete,

You got the most important part....the COLD beer....I can't seem to do anything anymore without it. Since I retired I have to include stocking the beer fridge as part of the checklist.....

Great job...Is this the DCS-10 or another variation of a Danley? Are you going to "Rabbit" the panels? I built two of the DCS-10 kits and Love EM.....!

W. C.

[Pete H]

Next it was time to take the router to the template so after cutting a couple of guide blocks to set the straight edge back the 2.25 inches for the router it was simply a matter of moving the template and setting the straight edge with a couple of quick clamps, really takes no time at all.

[Pete H]

Wish I was at the point where I could think about retirement.[Y] I'm not going to rabbit the panels at all; I considered it but to be honest with you I think that the right adhesive, pocket screws and a clean bead of sealant is more than sufficient. This is the build for the Danley couch sub that uses 2/ 8" drivers. I really don't expect to have some unbelievable difference with these vs the RSW 15's for HT, but after hearing so many good things I wanted to give them a listen.

[Pete H]

Once the routering is done, not that I think it's critical, but I did take the jigsaw and a knife and square off the ends. Keep in mind that I'm building this using glue and fasteners to hold it all together as I mentioned in my response to Heli,, so this template is for laying out the main panels and a fastening guide, and not a guide to router in the internal panels.

[Pete H]

Time to transfer the marks to the main panels. Note, that on the template I marked the corner that needs to be set and everything is marked off of that so that slight variations in the pieces are all set based on the same starting corner; if that makes sense. If not, then don't worry about it.[]

[Brac]

You got some tiny helpers? How you gonna pocket screw the second side?------------I disagree, you will see a huge difference between this and a rsw-15

[Pete H]

Marks transfered to the main panels. That's all for now, I have to go to the future in laws for a gathering; but next I'll cut the sides and internal pieces which won't take a lot of time as they are already ripped. For those of you that have already done this, please chime in now with all of the "if I was doing it again I would" I also want to hear about the dampening material and placement so I don't have to search through all the posts again please.

[Pete H]

The intermal parts of the horn won't need pocket screwed I'll just pocket screw the sides to the base and I will have small internal guides for the top section so the parts settle in the right location and they will be glued and then I direct screw them using the template as a screw guide. I hope you're right about the difference between the 15's and the
Spuds or this is all for nothing.

[CECAA850]

Love it![Y]. Keep the pics coming. I'll be building it vicariously through you to satisfy my need to build my next sub.

I do have a project in the wings for another forum member though. Maybe I'll get it going in the next couple weeks.

[psg]

Looks great! I have sent this link to my brother and a friend, both in need of this type of easy-to-build yet WOW sub.

[Pete H]

Looks great! I have sent this link to my brother and a friend, both in need of this type of easy-to-build yet WOW sub.

I have all the Tuba plans but decided to put one of these together quickly as a friend of mine just completed a Tuba HT like yours and I want to hear that, the spud and the RSW's on the same system in the same room.

[Pete H]

Love it!. Keep the pics coming. I'll be building it vicariously through you to satisfy my need to build my next sub.

I do have a project in the wings for another forum member though. Maybe I'll get it going in the next couple weeks.

Well don't hold back; what project do you have planned?

[CECAA850]

Love it!. Keep the pics coming. I'll be building it vicariously through you to satisfy my need to build my next sub.

I do have a project in the wings for another forum member though. Maybe I'll get it going in the next couple weeks.

Well don't hold back; what project do you have planned?

I'll let the eventual owner start a thread. For now, I don't want to side track (hijack) your build thread, but I will be riveted to it.

[psg]

Looks great! I have sent this link to my brother and a friend, both in need of this type of easy-to-build yet WOW sub.

I have all the Tuba plans but decided to put one of these together quickly as a friend of mine just completed a Tuba HT like yours and I want to hear that, the spud and the RSW's on the same system in the same room.

Sweet! Looking forward to hearing your thoughts on the comparison!

[Pete H]

I've been looking through some of the other builds again and I have a couple of questions for those of you who have done this or have run this box with different drivers.

1. Is the Tang Bank W8 740 P the best choice for this build? I want to place the order today so I have it by the middle of the week.

2. Does anyone have a specific amount of damping material and placement? I've read and seen a couple of versions and would like to know.

3. Is there a reason not to use acoustical foam ILO poly fill for the damping material?

Side note; the GF/Fiancé flipped out last night when she asked me why I was on the forum so much yesterday and why I would be researching and asking questions about a speaker that I'm not building now.[:$] After I explained to her that I had to test the new landing table for the saw and get the saw dialed back in prior to starting on the kitchen cabinets and that in this economy, I couldn't afford to just waste wood to dial it in I think her exact words were "you need to get your priorities straight", to which I replied, I love you too and which cut of diamond would you like for the engagement ring.

Will post some more pics a bit later today, but any response to the above would be appreciated.

[Chris A]

1. Is the Tang Band W8-740P the best choice for this build?

This driver had a higher Xmax than the one that originally was in the Danley TH-SPUD, and as I recall was suggested by gentleman from Australia in the DIYAudio thread. It has a somewhat peaking response relative to the original driver, whichever that was, but is easily EQed down to flat.

Keep in mind that frequency response peaks in the sub-40 Hz region are difficult to hear because of the ear's insensitivity at those frequencies. I found that the minimum dB boost that was audible in the 20 Hz region was about 2-3 dB.

2. Does anyone have a specific amount of damping material and placement?

Note that the amount of damping material used is somewhat user-dependent and application-specific. But if you don't have access to an instrumented microphone and a mixer to connect the microphone to a laptop running REW or something like it, I'd recommend stapling only in the driver and mouth areas of the sub to start with. These are the areas of maximum pressure wave bounce that is a bit more accentuated in the tapped horn design over a standard folded 1/4 wave horn design like the Tuba series. This is due to the generated acoustic waves' impedance mismatch with the air at the horn's mouth--and this effect is driven by the very compact design of the TH.

3. Is there a reason not to use acoustical foam ILO poly fill for the damping material?

I don't know what differences would be, but my initial questions in return are: 1) why do you ask?, and 2) polyfill is really inexpensive, why change?

Chris

[CECAA850]

After I explained to her that I had to test the new landing table for the saw and get the saw dialed back in prior to starting on the kitchen cabinets and that in this economy, I couldn't afford to just waste wood to dial it in I think her exact words were "you need to get your priorities straight", to which I replied, I love you too and which cut of diamond would you like for the engagement ring.

Will post some more pics a bit later today, but any response to the above would be appreciated.

I think you handled that situation with aplomb. Well done.

[Pete H]

1. Is the Tang Band W8-740P the best choice for this build?

This driver had a higher Xmax than the one that originally was in the Danley TH-SPUD, and as I recall was suggested by gentleman from Australia in the DIYAudio thread. It has a somewhat peaking response relative to the original driver, whichever that was, but is easily EQed down to flat. I must have misread something as I thought this was the original driver. What drivers did you use?

Keep in mind that frequency response peaks in the sub-40 Hz region are difficult to hear because of the ear's insensitivity at those frequencies. I found that the minimum dB boost that was audible in the 20 Hz region was about 2-3 dB.

2. Does anyone have a specific amount of damping material and placement?

Note that the amount of damping material used is somewhat user-dependent and application-specific. But if you don't have access to an instrumented microphone and a mixer to connect the microphone to a laptop running REW or something like it, I'd recommend stapling only in the driver and mouth areas of the sub to start with. These are the areas of maximum pressure wave bounce that is a bit more accentuated in the tapped horn design over a standard folded 1/4 wave horn design like the Tuba series. This is due to the generated acoustic waves' impedance mismatch with the air at the horn's mouth--and this effect is driven by the very compact design of the TH. I do have the equipment to test but absolutly ZERO experience doing it so I will start with your suggestions and then try to have someone walk me through the testing proceedure.

3. Is there a reason not to use acoustical foam ILO poly fill for the damping material?

I don't know what differences would be, but my initial questions in return are: 1) why do you ask?, and 2) polyfill is really inexpensive, why change? I just happen to have about 6 sheets of the acoustical foam which was the reason for asking. I can get polyfill instead, was just looking to use up what I had but didn't want to do it without asking.

Thanks for your help Chris.

Chris