Actual assembly has begun on my 1st pair of RS TMWW towers! :D

[jonathanb3478]

So, I got the DIY speaker bug again in May of this year. I built a 12" sealed sub 10 years ago or so. Nothing since then. In the first couple weeks of May, I picked up the tools I thought I would need for a new project. Since then, I have pretty much just worked through the design phase of a few ideas for enclosures. I finally settled on an enclosure design that suits my aesthetics and abilities (or notable lack thereof ).

I am a bit short on funds at the moment. I did get a $30 Home Depot gift card in the mail, and that got me a 4'X8' sheet of 3/4" MDF. Then the fun began!

I have now turned that MDF sheet into all the panels for the internal structure of both enclosures. Later, I will get the material for the external layer of 3/4" MDF (all sides are to be 1.5" thick), as well as the drivers and crossover components.

I have no need for the actual drivers or any veneering/painting for a little while. Hopefully, by the time I do, I will have some free cash.

I have selected the D.M. Seas tweeter version. I plan to try them sealed and ported, as I am building this pair for a new, stereo-only system in the bedroom. I do not want to deal with bass management in that system. Additionally, if the finished speakers perform to my expectations, I will be outfitting my HT and 5.1 music systems with three pairs and a couple of the matching centers.

I have learned a lot already, and I hope to learn more while constructing these speakers. For instance, now I know that it is impossible to have too many clamps, based solely on my own personal experience:

Image not available

:E :E :E

[ThomasW]

Okay, only 100 more photos and you're done.... :B

[jonathanb3478]

For the crossovers on these things, I think I am going to perform a little auditioning of cheaper woofer capacitor setups.

I have found that I can get a non-polarized electrolytic of 80uF for $1.80, and I can bypass that with a 20uF Dayton poly for an additional $4.95. This gives me the 100uF needed for the woofer, but costs just $6.75 vs the $19.51 for a 100uF Dayton poly.

That is $25.52 in savings per pair of speakers for just one substitution per crossover. I would like to hear what I get for my ~$25. This means I will have to buy both, but as I indicated, I will be making many more of these and do not want to spend more than I need to.

EDIT: Further a long this line of thinking is getting a pair of $1.85 np electrolytics also. Then I would have a pair of the 100uF Dayton polys, a pair of my $6.75 combos, and a pair of 100uF straight np electrolytics to play with. If it sounds acceptable to me, running the combos in the midrange and the straight electrolytics in the woofer would cut out $60.84 from a subsequent pair. That is a lot, actually. I will see what I think about the differences.

[ThomasW]

If you want to save money make the large value caps from clusters of the 10mfd GE closeout caps from Madisound. That will cut 50% off the price compared to using brand name film caps from PE or Madisound.

Edit to add, friends don't let friends use electrolytic caps... You may not hear a difference now, but in the longterm if you upgrade your electronics. you will hear a difference, and it won't be subtle....

[jonathanb3478]

Edit to add, friends don't let friends use electrolytic caps...

lol

Ok, I will look into the GEs. :T

[jonathanb3478]

Some more progress:

Image not available

The single round opening in the bottom of the back is part of the opening for my crossover access (and optional port tube) panel. The inner baffle is not yet attached to the front of the enclosure, yet.

Well, I ordered ~$10 of that MCM batting that you pointed out a while back, Thomas. I will be using it for the woofer portion of the enclosure. I will attach the other side panel, along with its vertical bracing runner, once I have that stuff arranged in there.

[truckman]

It looks like you've designed the third variation of the mid subenclosure. The other two that I'm aware of are dawaro's in post #187 in the sticky thread, and Jim Holtz's in post #307. How does the volume of yours compare to the others? It appears larger to me, but it is difficult to judge from the photos because of the differences in cabinet depth between the sealed and ported versions, and the internal width of your cabinet should be less to compensate for the double thickness walls that you are planning.

Of the three designs, I like yours the best. Jim's subenclosure is deeper that dawaro's, which is supposed to be desirable, but the restricted passageways between the upper and lower chambers in Jim's design has always bothered me.

My inclination when building the sealed version would be to enclose the tweeter in the mid subenclosure like you and dawaro have done, and then taper the top and or sides to adjust the volume of the subenclosure so that it can be as deep as possible while still allowing good airflow around its sides and/or back.

[jonathanb3478]

My version of the sub-enclosure is 7 liters.

It is 5.75" wide at the "mouth".

It is 1.75" wide at the back.

It is 10.25" tall.

It is 10.6" deep

The sides have an 11.75 degree taper after they go straight back for the first inch.




My internal width is actually even less than you would think for simply compensating for the 1.5" sides. I also compensated for the fact that my 3/64" veneer will be wrapped around the baffle and sides. I wanted it to be 10.75" wide after the application of the veneer.

My internal width was designed as 7.65625". Obviously I do not have the precision to precisely match that number, but I did my best. My internal volume is designed for 42" X 7.65625" X 19". That should be just over 3 cu ft after subtracting for the bracing and the sub-enclosure's volume.

[jonathanb3478]

A little more progress...

Images not available

[ThomasW]

You'll want to experiment with the amoumt of damping. Lining everything is a good start but it's not where you stop.

[jonathanb3478]

I understand, but a little bit of that will not be accessable to me after it is fully assembled.

If only I could train one of my cats to go in the crossover access panel and come out with an offending piece of batting. Goobie!!! Fetch!!! (he does play fetch, but only with plastic bottle caps)

[dyazdani]

If only I could train one of my cats to go in the crossover access panel and come out with an offending piece of batting. Goobie!!! Fetch!!! (he does play fetch, but only with plastic bottle caps)

:rofl:

[dynamowhum]

Could you imagine training the cat to do that and then build it as a ported version? I wonder how cats act as a sound dampner? Or imagine having some one over to audtion your speakers just to have to run the cat out of the speaker? Chuckle.

[dyazdani]

Yeah, you could have a sealed and a ported version, you'd just have to have two cats...

[jonathanb3478]

Or imagine having some one over to audtion your speakers just to have to run the cat out of the speaker? Chuckle.

Not for an audition, but I am afraid I will find my in-progress enclosures ~10lbs heavier, all of a sudden. Once I have the side panels on, if the crossover access hole is not blocked, they will have free reign in there. Those vent holes in the braces are all big enough for my cats to get their head through... and if that fits...

Trouble.

[mmoeller]

Yeah, you could have a sealed and a ported version, you'd just have to have two cats...

:rofl:

[jonathanb3478]

OK, I just measured the "diameter" of my cat's head at just under 3". That means I might have to "run the cat out of the speaker" for an audition. THIS IS NOT FUNNY! (well, ok, it is)

So the question is now, do I use a 3" port or a port grill? :M

[cobbpa]

you'd just have to have two cats...

...you'd have two cats for a while... :lol:

[dynamowhum]

So would the question be not how to tune a port but how to tune a cat?

[Brian Walter]

I also have a cat, that's why I went with the sealed design:-). Although, I don't think my cat would fit in a 3" diameter port hole, but he probably would a 4". I've had to be carefull when I've had the heat vent covers off for painting and such to make sure the darn cat doesn't get in there. I'm working on designing a sub now that will likely have a 5" or 6" port, I know he would crawl in there. Maybe I need to rethink the plan and go sealed.

[joecarrow]

Ideas... a slot port, or multiple smaller ports, or we could find out if chicken wire causes chuffing.

NEVER give in to a cat- that's one thing I try to live by. They want to wake you up at 5 AM for more food, even though their bowl is still half full? They want to sit in your chair? The instant you stop hissing at them and making faces, and flapping your arms and shouting abuse, they'll just walk all over you. If you want that ported speaker, go ahead and build it.

Some people call me "The Cat Puncher"*, but really I'm just grumpy because I let my girlfriend's cat get the better of me.


*disclaimer: people don't call me that, but I wish they would.**



**second disclaimer: I don't advocate or practice cruelty to animals

[Martyn]

I'd imagine that a cat is probably quite a good alternative to acoustic stuffing, especially for floor-standers if you can get it to curl up on the bottom panel. If you have access to a variety of cats of different volumes and fur thicknesses in your neighbourhood, they could be a very useful empirical tuning aid.

[ThomasW]

If one is concerned about animal incursion, cover the end of the port with nylon window screen or grill cloth..

[truckman]

Ideas... a slot port, or multiple smaller ports, or we could find out if chicken wire causes chuffing.

How about one of those wire finger guards that block are used in front of fans? This site sells both wire finger guards and finger guards stamped in various patterns.

NEVER give in to a cat- that's one thing I try to live by. They want to wake you up at 5 AM for more food, even though their bowl is still half full? They want to sit in your chair? The instant you stop hissing at them and making faces, and flapping your arms and shouting abuse, they'll just walk all over you.

I once adopted a cat named Nuisance who refused to eat unless I was watching. He would wake up at some unreasonable hour of the morning and would circle the bed and whine until I got up and accompanied him to the kitchen. I tried to ignore him, but two hours of whining was more than I could stand. Even if I waited for him to start eating before returning to bed, he would stop eating, return to my bedroom, and start whining again. He would eventually get angry if I interrupted his breakfast that way too many times. I eventually put a bowl of food next to the bed so that when he was hungry in the morning I could satisfy him by rolling over and pointing at the food.

[JonP]

So would the question be not how to tune a port but how to tune a cat?

You can tune a port, but you can't tune a cat!!

But you can feeda the cat a tuna!!! :rofl:

<rimshot>

[dyazdani]

This cat needs a good tuning... :rofl:

Found this today, thought it was fitting, sorry to contribute to the thread's misdirection...

[jonathanb3478]

Thanks, truckman. I like this one:

http://www.directron.com/atom120mmchr.html

[jonathanb3478]

As of right this minute, the other enclosure is in the same build state as the the one in all the above pics. I am waiting on a cable order to arrive in the middle of next week. At that point I will have already put the batting in this second enclosure and will wire them up for the drivers with the contents of my order. Once that is done, I will then glue on the internal side panels.

I should have my next sheet of 3/4" MDF by then as well, and I can start cutting the external enclosure pieces.

Slow but steady wins the race, right? :T

Well, I hope so.

[joecarrow]

Patience pays, it will be worth it!

[jonathanb3478]

So, I picked up the wiring shipment at the post office this morning. I got both speakers wired how I want them, now. I will go ahead and glue on the inner enclosure side panels, tomorrow. I will have to cut the damping material for the side panels, and tack it all on. I will then need to make sure it does not get caught in the glue joints during assembly. I anticipate that to be a bit frustrating. I am way too tired to deal with it right now, unfortunately. I am barely able to finish my laundry before I go to bed. :Z

[dynamowhum]

Okay Johnathon enough slacking it's been two days we want an update.

[jonathanb3478]

LOL

That is kinda what it has been.

I brought out my Forstner bits a couple days ago and drilled the holes into the sub-enclosure for the cable that finally arrived on Tuesday. The MCM order with the wool/poly mix batting showed up on Tuesday, too. Any way...

When I went to select the bit, I grabbed the 3/8" (smallest I have that is not too small for this job) and set it aside to use later. Then when I went to put a bit into the drill, I grabbed the smallest one in the row where that should be the 3/8" bit. Instead, I ended up making a 1/2" hole. I had forgotten I had removed and set aside the 3/8" bit. ops:

It took me a day to figure out how I wanted to fill all the extra space to restore an air tight fit. What I had planned to use with the 3/8" hole was a bit of 60-minute epoxy. I did not want to work with that much of it, however. It did actually take me an entire 24 hours to figure out I could grab some of the MDF leavings in the plastic "dust capture" grocery bag below my drill press and mix it with my Titebond and fill with that combination. It took me another 24 hours to gather the energy to make and clean up such a mess in the living room. 8O

It worked well. It is, however, going to be allowed to dry for a full 24 hours before I mess with the enclosures any more. That timer has another 14 hours on it.

No more working with power tools when I am tired. :Z

[dynamowhum]

Johnathon that is a great trick with the glue. It also works for regular lumber as a filler as well. I had something similar happen when routing my mid. I had set my router over to the side and it fell over. Well that knocked the stop which made me plunge my recess a little deep for about a 1/2" before I realized what happened. I think I'll use your glue trick to remedy that. Now where did I put that little vac.

[Brian Bunge]

Another option is to buy a dowel the size of the hole you want to fill. Simply glue it into place and cut off any excess sticking out. Then use a palm sander to sand down any rough spots. I did this on the first subs I built where I actually drilled holes for the binding posts at the bottom of the enclosure's back instead of the top. Worked like a charm and even with painting the enclosure you couldn't tell there was ever a mistake.

[jonathanb3478]

If you want to save money make the large value caps from clusters of the 10mfd GE closeout caps from Madisound. That will cut 50% off the price compared to using brand name film caps from PE or Madisound.

Well, the 10uF GEs were no longer available by the time I placed my order. I decided to order 625uF worth of the 5uF caps that are still available. That is 125 caps. At that quantity, they are $.50/each. This is enough to cluster them for the two 100uF and the two 115uF values in my first pair. It also leaves quite a few left-over for spares, or even another project. The cost of the ones I need for this first pair (with shipping, even) is ~$51.

The values are +/- 10%, however. I figure that is ok, since I already planned on buying a capacitance/inductance meter. I will be able to use the one I get to create clusters within an acceptable range of the needed final value.

EDIT: UPS says I will have them on Tuesday, except it appears they are ahead of schedule and Monday is likely.

[ThomasW]

The values are +/- 10%, however. I figure that is ok, since I already planned on buying a capacitance/inductance meter. I will be able to use the one I get to create clusters within an acceptable range of the needed final value.

They will all be slightly under 5mfd. So you'll need to add to get the values you need. Wait until you have the clusters assembled then measure and order the values needed to 'trim' the final value.

We buy a length of copper antenna wire from Radio Shack and tin it. That's used as the bus to attach the rows of caps. Looks like this only much, much bigger.....

[jonathanb3478]

Pics, come get your pics here!!!


Image not available

They will all be slightly under 5mfd. So you'll need to add to get the values you need. Wait until you have the clusters assembled then measure and order the values needed to 'trim' the final value.

Well, that is unfortunate. Still, beats paying ~$20 for 100uF.

They will all be slightly under 5mfd. So you'll need to add to get the values you need. Wait until you have the clusters assembled then measure and order the values needed to 'trim' the final value.

We buy a length of copper antenna wire from Radio Shack and tin it. That's used as the bus to attach the rows of caps. Looks like this only much, much bigger.....

I have ordered some 12ga for the bus wire. I will strip the insulation in the middle at the appropriate spots to solder the cap leads.

I will say I miss working with 0ga wire. I always enjoyed using my mini-blowtorch. :twisted:

[joecarrow]

Wait... do I just not see the countersink? How are you mounting the drivers?

Edit- I didn't consider that you might be doubling the thickness of the front baffle.

[jonathanb3478]

Edit- I didn't consider that you might be doubling the thickness of the front baffle.

Well, I am doubling the thickness of the front baffle, along with every other enclosure wall.


Also, the other speaker is now at the same point as the one in the image. It will be clamped for a while longer, however.

[yousuredo2]

Looking good !

[jonathanb3478]

So, I got the GE cap order from Madisound earlier today. They are 1 5/8" X 7/8" X 5/8" or so. The leads are each ~1.75" long, as well.

I ordered 125, and there were 126 in the shipment. So, if one is DOA, I am still covered. But...

My only concern is that they came 40 to a cardboard sheet, and on each of the three sheets it indicates that they passed "QC" (quality control) on 1/22/96. These are not spring chicken caps.

I would not think that hanging around in a warehouse for a decade would harm them. I would be more concerned if they has been operating for the last 10 years, but still - that is pretty old. The price is right, however.

It will be a few weeks 'till I have an inductance/capacitance meter, so I just put each sheet in a ziplock bag, and the ones that were not on a sheet in a different ziplock.

Here's to progress by degrees. :T

[ThomasW]

I've been buying the same caps since Madisound first offered them. I have multiple boxes of 100 pcs in the basement. They've all been fine.

[cobbpa]

jonathon--

what post in the original thread details the box design you're using?

[jonathanb3478]

jonathon--

what post in the original thread details the box design you're using?

Hmm...

It is this thread, not the original one:

https://www.htguide.com/forum/showthread.php?t=20454

In the thread linked to above, I figured out what woofer enclosure and sub-enclosure volumes I wanted to work with. This was finally based on Win-ISD sims of ported and sealed designs using a pair of RS225 woofers. I did not think ported was worthwhile until the enclosure was at or above 3 cu ft. I intend to hear this pair in both a sealed and ported allignment. I will then pick which I like best for this stereo only pair for my bedroom. I also wanted angled sidewalls on the sub-enclosure. You can see the design of the sub-enclosure in the thread above and this one are the same. Keeping all this the same tells me if the eliptical enclosure will work well. It should sound very similar to this one. Same woofer enclosure volume, same sub-enclosure volume and shape.

There is a sentance in the first post of this thread that touches on why this enclosure is not a stack of eliptical panels, even though it is the same total volume for the woofer enclosure and sub-enclosure:

I finally settled on an enclosure design that suits my aesthetics and abilities (or notable lack thereof ).

I finally realized it would take forever to get results with my original method. I switched to a box enclosure for the first one, as I wanted something on a shorter timetable. I am also looking into a DIY CNC Router project, before moving on to the eliptical translamination version of this design.

[jonathanb3478]

So, I have a question for the woodworkers here, related to this project.

I want to use some design elements in this project that I think look really cool. The problem with them, is that they will make side walls that are not PERFECTLY flat rather easy to notice. The side walls I am interested in sanding to flatness are ~20.5" wide by 43.5" tall.

I am wondering if a method exists, with the resources I have available, to sand the sides and back of this enclosure to a very uniformaly flat surface. A perfectly square enclosure is not really critical, and my construction to date is pretty decent in that regard anyway, but a process for getting actually-flat side walls (in the vertical dimension) would allow me to build the design to look how I want it. Well, with out highlighting any build flaws to the point of obviousness.

A rundown of the resources I have, which I would think might be useful in achieving my goal:

24" steel framing square
steel yardstick (not convinced this think actually has a straight edge on it)
5" random orbit sander
1/4 sheet powered sander
1/2 sheet hand-sanding block

Thoughts/comments/ideas?

Please?