# New Stuff I'm Building...



## InfernoSTi (Oct 31, 2010)

OK, I decided my 2.5 watt MiniWatt amp needs a little more oomph down low. Solution? Build bigger baffles and add 15" Hawthorne Audio Augies and a Dayton plate amp! That should just about do it!!! My project may take a little while to finish, but I've made a good start already:


----------



## engtaz (Jul 9, 2010)

Thanks. Keep the pics coming.


----------



## django1 (Jan 28, 2009)

Nice circles! What kind of a jig did you use on the router?


----------



## skeeter99 (Jan 24, 2007)

django1 said:


> Nice circles! What kind of a jig did you use on the router?


Looks like a *Jasper Jig 200* to me:


----------



## django1 (Jan 28, 2009)

skeeter99 said:


> Looks like a *Jasper Jig 200* to me:


Hey thanks! I'm glad I asked...


----------



## InfernoSTi (Oct 31, 2010)

That is the Jasper Jig indeed! Easiest tool you will ever use...


----------



## dvenardos (Sep 27, 2008)

I just ordered one from Amazon.


----------



## django1 (Jan 28, 2009)

Can I borrow it:eyebrows:?


----------



## Eddie Horton (Nov 8, 2006)

I made a circle jig out of a piece of lexan. Just drill and countersink the holes for the mounting screws and you're in business. Measure from the edge of the bit to whatever radius you need and drill a hole in the lexan for the pivot point. Works great for cutting multiple holes of the same size. Not so much when you have a bunch of different size circles. You end up with a lot of holes in the lexan and it gets to be a pain. Buy, hey.....I'm cheap.


----------



## dvenardos (Sep 27, 2008)

Sure, but with shipping back and forth to Canada I think it would be cheaper for me to just buy you one. 
BTW, the one I got was stocked by Amazon with free shipping, but I also noticed that for products offered by PartsExpress via the amazon storefront the shipping was cheaper than ordering directly from PartsExpress.


django1 said:


> Can I borrow it:eyebrows:?


----------



## InfernoSTi (Oct 31, 2010)

Here is the "plan" for the baffles and a photo of one of the base boxes being built. I'm pretty covered up at work and at home so it has been a task to find the time to put into this little project. I had hoped to have them finished in April but now I'm hoping for May. Oh, and I don't profess to be a woodworking craftsman...this is my first DIY project and I'm learning as I go!


----------



## Jason Brent (Mar 28, 2009)

cool stuff....keep us posted!


----------



## InfernoSTi (Oct 31, 2010)

Test fitted one of the OB's this evening! Perhaps not the finest craftsmanship (see Lead Suspect for that!!!) but playing one unfinished with a mono Augie and the other speaker in a temporary baffle, it was everything I had hoped for and well worth the effort (even though I'm only halfway done with the build (and then I have to stain them!). I am learning every step of the way which has been really enjoyable.


----------



## InfernoSTi (Oct 31, 2010)

FINALLY got the second baffle built and it is being test fitted so I'm finally stereo with two 10" drivers/compression tweaters and two bass augmenters.

I am extremely pleased with how musical, detailed, and fast paced the Hawthorne's are...and the Augies really fill in a solid foundation. The sound stage/imaging are a treat to experience! I couldn't be happier with the progress this project is making!


----------



## PhenomeNhan (Mar 4, 2008)

Congrats on the finished products. They look really nice. I may have to drop by for a demo


----------



## django1 (Jan 28, 2009)

Interesting.


----------



## InfernoSTi (Oct 31, 2010)

PhenomeNhan said:


> Congrats on the finished products. They look really nice. I may have to drop by for a demo


That would be great! However, I will need to clean up my VERY messy home office when you do....I'd be interested in hearing your thoughts.


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> Interesting.


Very.

I find I really like the way they sound...however, I'm no audiophile so I don't pretend to know more than what I like!


----------



## tesseract (Aug 9, 2010)

Someday I would like to build a set of OB's just to see what they are about.


----------



## InfernoSTi (Oct 31, 2010)

I see I failed to mention I am currently driving the system with my 2.5 watt MiniWatt and driving the two Augies with a Dayton 240 plate amp crossed over at about 110 hz with a 24 db slope. This really adds the foundation that the MiniWatt was lacking down low. With that first magic watt, I'm getting plenty of volume in my small home office with 96db drivers.


----------



## Steve_Vai_rules (Jun 22, 2010)

wow, looks amazing! lusone:

any new pics of the finished product? what stain did you choose?


Matt


----------



## InfernoSTi (Oct 31, 2010)

Thanks Matt! I haven't made any progress on "finishing" the speakers because I started another DIY project to go with them: I built a SPUD amp from a kit (a pre-drilled case, a bag full of parts, and a schematic & basic instructions). I intend to mount it with matching wood/stain. Right now it is just in a "C" shaped case. I am listening to it right now, actually! I'm very happy with the clarity, detail, and soundstage. And the feeling of accomplishment is very satisfying. John


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Thanks Matt! I haven't made any progress on "finishing" the speakers because I started another DIY project to go with them: I built a SPUD amp from a kit (a pre-drilled case, a bag full of parts, and a schematic & basic instructions). I intend to mount it with matching wood/stain. Right now it is just in a "C" shaped case. I am listening to it right now, actually! I'm very happy with the clarity, detail, and soundstage. And the feeling of accomplishment is very satisfying. John


Nice looking amp. That's my next DIY electronics project, been looking at a bunch of different kits, just need to decide on one. It will go with my DIY speakers (probably a something from GR) peoject.

Glad it sounds good! 

I eagerly await to see everything stained/lacquered/shellaced/painted.

Any other DIY's on the horizon?

Matt


----------



## InfernoSTi (Oct 31, 2010)

Steve_vai_rules said:


> Nice looking amp. That's my next DIY electronics project, been looking at a bunch of different kits, just need to decide on one. Any other DIY's on the horizon?


Matt,

Yes, actually. I have the DIY bug and figured I needed a project or two to keep my momentum moving forward! So I have pre-ordered the Bottlehead Stereomour 2A3/45 SE amp. I've read good things about Bottlehead and this seemed like the next logical step after my SPUD. The should ship sometime this month, so I will get started whenever it arrives.

You ought to check out Bottlehead's kit amps...they are nice folks on the forum over there...lots of good information on DIY amps and associated tweaks. That being said, you wouldn't be disappointed with Jerry's SPUD from Hawthorne Audio, especially as as first time amp build!

John


----------



## Steve_Vai_rules (Jun 22, 2010)

thanks for the advice! I have heard lots of good stuff about spud and bottlehead kits in fact those seemed to be the more highly recommended kits..

i also have a cost no object 2-channel setup in the works, figure i will try some accuton drivers and do a 3 way tower with matching sub tower and do some DIY cables, a diy preamp and of course DIY amp. I am thinking of doing a ucd design. also using active xo's.  its a project that i will be working on later on next year. but my fiancee is an artist and loves to draw and design etc. etc. and she is in fact doing all the architectural work on these for me and doing detailed plans and is actually helping push the project along.. and i will get her to draw out all the circuits etc. well ask her too, lol. she doesnt consider herself technically very inclined but does like to participate.. this way we can both share in this hobby. speaking of which my diy participation of late has been almost nil, been doing fixes around the house had to dismantle and fix a broken shaft in the engine of my riding motor. change a cv joint (may have to change hub on the opposite corner) of my dad's ford escape, fix a broken valve on the hot tub, fix the non functional hand brake on my fiancee's car, paint the front and back door, have to finish up my studio room and also plan on tearing a wall out on the second floor... and of course my health aint too great either.. :hissyfit: lol anyways, just my rambling whining haha


I look forward to seeing some more diy stuff from you! and again thanks for the advice on kits.

its always nice to see fellow enthusiasts building their own stuff or tweaking!




Matt


----------



## InfernoSTi (Oct 31, 2010)

Well, I have ordered a 3 pack of 4" Owens Corning 703 (acoustic) insulation. Now I need to design a room treatment around them! 

My current thought is a diffusion front/bass trap back type affair for behind my OB speakers. The front would keep the brightness from a diffusion treatment while the backs would be absorbing reflections off the front wall and collecting bass. The third 703 would be nice on the wall behind/above my listening sofa chair to cut down on reflections there. It's a small (10' x 13') room with hardwood floors. With a set of open baffle speakers, bright is the word to use!

Nothing like starting with the main ingredient and figuring out the recipe!


----------



## InfernoSTi (Oct 31, 2010)

Here is the first of the three I am building: 

The front is a diffuser (remember this is with my dipole OB speakers so I need diffusion on the side of the front wall, not just on the side and rear walls. There is 4" of OC 703 behind the front diffuser. I pull it out across the corner for serious listening. I used some nice wood and then slopped on too much stain, but I'm learning. Overall, I'm pretty pleased with the "vintage speaker" look and how well it matches my hardwood floors (a rug is in order, I know). Sorry the first two loaded sideways. If I was a cool tech guy I would know how to fix that....

John


----------



## InfernoSTi (Oct 31, 2010)

And I added stained oak sides to my SPUD amp project (matches the "two in one" diffuser/bass traps).


----------



## Steve_Vai_rules (Jun 22, 2010)

nice! looks like a great listening space! I need to make some diffusers like that!! :scratchchin:

:applause:

Matt


----------



## InfernoSTi (Oct 31, 2010)

Steve_vai_rules said:


> nice! looks like a great listening space! I need to make some diffusers like that!! :scratchchin:
> 
> :applause:
> 
> Matt


Thanks, Matt. It is starting to feel like MY space...and sound GOOD! I can tell you that it is impossible to have too many diffusers and bass traps if you have a small room. Absorption isn't what I'm talking about, either. Keep all of that music energy alive!!!

One down and two to go. Of course I have my other two 4" panels of OC 703 in my corner in a temporary bass trap...the shipping box...sounds great too! 

Interestingly, having a shallow diffuser behind my listening sofa chair made a very noticeable difference. Makes sense that in such a small room, I would get that immediate first reflection off the back wall directly on my ears. 

John

P.S. Let me know if you are interested in some of the room treatment sites I've been learning from...


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Thanks, Matt. It is starting to feel like MY space...and sound GOOD! I can tell you that it is impossible to have too many diffusers and bass traps if you have a small room. Absorption isn't what I'm talking about, either. Keep all of that music energy alive!!!
> 
> One down and two to go. Of course I have my other two 4" panels of OC 703 in my corner in a temporary bass trap...the shipping box...sounds great too!
> 
> ...


"thumbsup:

For sure let me know what websites you have been using. I am still playing around with positioning large couch cushions and REW to figure out what needs to be done. Very much a trial and error approach. lol

Look forward to reading about the changes once you get all the treatments finished and in place!

Any other tweaks you have in mind for your setup?

Matt


----------



## InfernoSTi (Oct 31, 2010)

Matt,

Having listened (without empirical testing), I can say that room treatments have a positive impact on your listening room. In my opinion, it is in the upgrade chain as follows: select better speakers, then better DAC, then better amp, then add room treatments, then look at tweaks such as cables, tube rolling, etc, then revisit speakers (repeat the cycle). It seems most people jump straight to tweaks or start over at new equipment. I have found more value from room treatments than appears to be generally understood.

Here are a few quick links. Most of what I am doing requires a bit of a different approach as my OB speakers are true dipole speakers that really complicate the concept of "first" reflection points in a small room. 

http://www.realtraps.com/art_basics.htm

http://www.ethanwiner.com/basstrap.html

http://www.basstraps.net/DIY-BASS-TRAPS-MADE-EASY.pdf

http://www.youtube.com/watch?v=aHkAFSZmMk4&feature=related

http://www.youtube.com/watch?v=dB8H0HFMylo&feature=related

The general rule that seems to be common across all sites is that you can never have too many bass traps or diffusion panels, but absorption panels can be over done and may result in a "dead" room. The more bass traps, the flatter your bass response due to reduction of peaks and nulls from wave resonance. The greater the diffusion, the more detailed and spacious your sound stage will become as you reduce the negative impacts of first reflections.

My best recommendation is to order a three pack of 4" Owens Corning 703, leave it in it's box but place that box across a corner and see if you can hear a difference. In my small 10x13 room the change was immediately noticeable without any effort at all. Your results will obviously vary based on your room acoustics, personal taste, etc. 

As far as new tweaks, I suspect that I will do another bass trap to finish out my treatments. I need something for a third corner that has to be about 1' square. I am thinking of making a 12" tube 8' tall filled with OC 703 but that may change.

How about you? Did you find an amp to build yet? Something else, perhaps?

John


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Matt,
> 
> Having listened (without empirical testing), I can say that room treatments have a positive impact on your listening room. In my opinion, it is in the upgrade chain as follows: select better speakers, then better DAC, then better amp, then add room treatments, then look at tweaks such as cables, tube rolling, etc, then revisit speakers (repeat the cycle). It seems most people jump straight to tweaks or start over at new equipment. I have found more value from room treatments than appears to be generally understood.
> 
> ...


Thanks for the websites. been reading lots of stuff by ethan winer and by linkwitz as well.

My room is odd shaped and huge, will post some pics of the full room soon. But diffusion would likely only be used in a few spots and absorption used in lots of others. Just to get the virtual space to be more evened out. The right side wall is much closer then the left by about 5 3/4 feet there is also the main ducting trunk going over the left side with the sofit that contains it being about 35 feet long and about 4 1/2 feet wide (also there is an engineered steel beam in the sofit too). There is also an open stairwell on the back left of the listening position and back right there is an 8 foot long 5 1/2 foot deep alcove that my fiancee uses as an office space, there is also a large area behind the listening position that has a pool table. It's an acousticians nightmare.  I am going to put diffusors in the back half of the room so there isn't a bunch of direct reflections and the front is going to likely be a combination of diffusors and absorption. There is also book shelves everywhere... My family are book collectors it seems and my house is filled a couple thousand books. There are about 25 book shelves (most large) located throughout the house. And that doesn't include the stacks of boxes filled with books stuffed into every available crawl space and closet and storage space.. :nervous: annnnyways, on top of that I can't make any physical changes to the space as it is an already completed basement (that took me much time, effort and expense to complete). And I wanted a partial open concept game/hang out/chill out space. The pool table is down here, and it's a nice open airy spot to hang out either at night or during the day. 

As for what I have planned next well.... hahaha umm read this thread of mine on AVS http://www.avsforum.com/avs-vb/showthread.php?t=1264289 The gist of it is that I have decided to build a set of cost no object active cross over speakers. I wanted a set of really nice speakers for 2 channel and was looking at different commercial models or building someones kit and just decided that I want something completely unique... :crying: Not sure what amps I will use to drive the individual drivers (with the active crossover each driver will be getting it's own amp). I am thinking about going with the UcD hypex class D units, they seem to be some of the best class D amps out there and are compared to some top class A units. Later I may build a couple 100 watt Aleph-X units (roughly passed on the pass labs XA series amps). But I may just keep the hypex amps and add some tube buffers to the mids and tweeters like the dodd tube buffers. I am likely going to go 100w/driver for amp power. And the drivers I am looking at will be the higher efficiency accuton units. And do servo subs based on rythmik servos. I like craigs stuff but I just can't incorporate it into my design plus it's cheaper for me to get materials and drivers and amps and build it myself then may import and shipping fees for something as large and heavy as 2 or 4 18.2s (which I would need considering the size of my space and it's openness).... Materials choice is going to be a bit out there, I plan on using aluminum for the frame/bracing of the speakers, and carbon fiber laminated with a couple other materials. And a base made of granite or stone or thick acrylic. Not sure what I will be doing about the active crossover, and am still looking at options which is primarily what that thread over at avs is about, but I believe I have narrowed that search down to the DEQX unit.

http://doddaudio.com/diy.aspx
http://www.hypex.nl/
http://www.rythmikaudio.com/DS1500driver.html
http://www.deqx.com/products.php

Yeah I know it's gonna cost a lot but I figure this will be a fun build that will take me to another place with listening gear. And give me a chance to listen to super high end sounding gear without spending 60 thousand dollars or more.

Matt


----------



## InfernoSTi (Oct 31, 2010)

Wow! I'm proud I was able to talk my significant other into my bi-amped three way. Five way pent-amped and active? Does the GF approve? Just kidding. Did I say WOW already?!!! That should provide endless DIY construction and tweaking!


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Wow! I'm proud I was able to talk my significant other into my bi-amped three way. Five way pent-amped and active? Does the GF approve? Just kidding. Did I say WOW already?!!! That should provide endless DIY construction and tweaking!


she mostly approves. mainly because she benefits by me spending more time at home and less being stupid with my friends or doing stupid things :fryingpan: , and also it means i will be spending money on something she can enjoy versus say a yamaha R1 and track time :tanks alot: :dizzy: plus she kinda likes this project because she gets to help me design stuff and do drawings and help me pick out finishes ya know girly stuff 

I am hoping this provides endless tweaking and DIY chances. 

looking at 4 or 5way not sure yet. 

sorry to thread jack

I am sure you will manage to come up with new and interesting ways to improve your system. course it's looking pretty rockin' right now! 


Matt


----------



## Steve_Vai_rules (Jun 22, 2010)

something to think about with your treatments: you do have hardwood floors and although you sit close to your speakers you could be getting some reflections off the floor. A nice area rug may help with that, or hinder it. Either way it's easy to test out by just tossing a rug between you and the speakers.

I only mention the rug because my fiancee hauled the area rug in my listening space outside to clean it and I sat down to do some passive listening while i did some reading and I was wondering why everything seemed sharper sounding. Then it hit me "ohhh yeaaaaah rug is helping with some of the high frequency reflections", I need to do some proper measurements and talk to an acoustician. Maybe that is just one more small thing to help improve the sound. Plus it may get that other special person involved by letting them choose a carpet and explaining why it helps. *shrug* 

How big is your room? did a look through the thread and couldn't see that info could you maybe post a pic that shows more of your space?


Matt


----------



## InfernoSTi (Oct 31, 2010)

Matt, 

I've been thinking about the oddly shaped room. Diffusers should help even out the sound stage on the side first reflection points. As far as the rear wall, there is the notion that your seating should be a bit more than 1/3 of the total room depth, leaving a little less than 2/3's behind you. 

http://www.realtraps.com/art_room-setup.htm

I'm not sure how much having a stair well behind you on one side and an alcove/office on the other side will affect the sound. Perhaps it becomes a wash? I guess I would rather have too much space than too little!

My room, on the other hand, is 13' wide and 10' deep, so when I pull my OB speakers 3' off the back wall and push my sofa chair all the way back so my head is 1' off the rear wall, I still only get 6' between my ears and the speakers. The ceiling is 10' which helps a bit. 

I am putting together a wall mounted diffuser that will be made from matching wood/stain as the "two in one" diffuser/bass trap I posted. Since my head is one foot from the wall, I get crazy first reflections that make the upper end harsh. I had one there temporarily and had noticeable results, so I am hoping to finish it this weekend if at all possible.

You are absolutely correct. I need a small rug for in front of my speakers. And that is a FANTASTIC idea to get Jeanine to help me shop for the rug...she would love to do that! Nice idea!!!

John

Edit: after dinner out with Jeanine, we wandered around a home furnishings store and looked at possible throw rugs, ottomans, and stuff she likes. She suggested I go by Pier 1 and World Market and look there, too! I'll drag her along and she will have fun I'm sure. Bonus points!!!


----------



## InfernoSTi (Oct 31, 2010)

Here are a couple of photos of the "behind my ears" diffuser project. I'm pretty happy with my 45 degree cuts on the main frame, as well as the stain on this one. I am using a combination of 1x2s at various angles and 1" and 1 1/4" dowels (infinite angle). I am also leaving a little room for some sound to pass through to the wall and diffuse on the way back, too. Remember, this is 12" behind my ears above the sofa chair, so it has to be shallow and break up the sound waves as effectively as possible. All this will be covered in burlap matching the earlier "two in one" diffuser/bass trap. 

John


----------



## InfernoSTi (Oct 31, 2010)

Matt,

I really like the look of that Dodd Audio battery equipment. Interestingly, I recently ordered a Bottlehead Quickie battery powered pre-amp to play around with. Now the Dodd equipment seems to be in the $1,500 range, this Bottlehead product is in the $150 range. However, the concept of a pure DC pre-amp is just intriguing, so I went ahead and took a baby step in that direction. I didn't order the case and intend to build an oak case stained to match my room treatments.

The Rhythmik sub driver looks very musical. At some point, seeking distinction in the bsss notes, rather than simple abundance, is where two channel goes. Home Theater really focuses on the chest thump, and don't get me wrong, that is a great experience. But you find yourself enjoying the bass player if you manage to find the right equipment and room treatment. Oddly enough, my other recent order was an Open Baffle specific Rhythmik sub amp to power my two 15" Hawthorne Audio Augies (Open Baffle subs). In my research, they make very musical amps and have personal customer services. Again, I plan to make a nice oak case stained to match my room treatments.

I'm so busy with my set up efforts, I haven't even begun to think about active systems. I did notice the Emerald Physics OB speakers are all about active systems like your link to deqx system. They use four channel and are quite the thing, so they say (I haven't listened to any myself but have to say that I use Hawthorne Audio drivers which are made by Eminence as well). I will say that their system caught my eye a few months back. They basically convert your Mac to an active system so your source is also your crossover. Being a Mac guy (I know, everyone is these days...and they should be!), this seemed pretty cool. Here is the link to that equipment on 6moons: 

http://www.6moons.com/audioreviews/emerald/emerald.html

Very enjoyable projects...and the reward is music that moves your soul. Hard to beat the value of that in our lives!

Take it easy, John


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Matt,
> 
> I've been thinking about the oddly shaped room. Diffusers should help even out the sound stage on the side first reflection points. As far as the rear wall, there is the notion that your seating should be a bit more than 1/3 of the total room depth, leaving a little less than 2/3's behind you.
> 
> ...


Glad you are scoring bonus points AND helping better the sound in your room! :biglaugh:


Thanks for that link to 6moons, the spatial stuff looks interesting! *i'm a mac guy too* lol


Matt


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Here are a couple of photos of the "behind my ears" diffuser project. I'm pretty happy with my 45 degree cuts on the main frame, as well as the stain on this one. I am using a combination of 1x2s at various angles and 1" and 1 1/4" dowels (infinite angle). I am also leaving a little room for some sound to pass through to the wall and diffuse on the way back, too. Remember, this is 12" behind my ears above the sofa chair, so it has to be shallow and break up the sound waves as effectively as possible. All this will be covered in burlap matching the earlier "two in one" diffuser/bass trap.
> 
> John


That's gonna look great when it's done! 

Have you thought about doing an uncovered diffusor and just stain the wood slats?

Matt


----------



## InfernoSTi (Oct 31, 2010)

Matt,

Found the thread again! A couple of things. First, I did go ahead and get an inexpensive rug ($28) and it made a big difference...great call. Those first reflections off the hardwood floor were really causing an issue.

Second, I have a couple rolls of R-13 still in plastic sitting in the corner and that made a huge difference! Now I just need to package it appropriately! Making a flat lower end is so important. I would encourage anyone who doubts it to stack $75 worth of R-13 in their listening room corners! If you leave it in the plastic, you can always return it if you don't hear an improvement! 

Finally, to answer your question, if I was better with woodworking, I might make a diffuser that left the wood. I will get better with projects and may come back to this idea...it could be very cool. 

Thanks again for the tip on the rug! 

John


----------



## Steve_Vai_rules (Jun 22, 2010)

Glad I could help  hope your significant other enjoyed being involved in your audio hobby/love

I am looking at building some wood diffusers after seeing them all over the place. I really like the look they add to a room. They seem to integrate better into other decor themes than the foam diffusers. It's why I suggested the exposed wood look.


Look forward to some pics of the room when you finish your treatments!


"thumbsup:

Matt


----------



## dguarnaccia (Jul 17, 2008)

John, 

One thing you can do it buy tube shaped insulation and stuff it with normal insulation. I use the 16 inch diameter tubes in my room, and they work well...you can buy em from local building supply shops. I used this stuff from Knauf http://www.knaufusa.com/products/co...t_insulation/1000°_pipe_insulation_ecose.aspx

Then I wrapped 1/2 of it in 2 mil plastic to reflect the high frequencies and put them in all the corners. It really helped damp the long decay bass in the room. 

These wind up being similar to the ASC tube traps, just a lot cheaper to make and look cool.


----------



## InfernoSTi (Oct 31, 2010)

Steve_vai_rules said:


> Glad I could help  hope your significant other enjoyed being involved in your audio hobby/love
> 
> I am looking at building some wood diffusers after seeing them all over the place. I really like the look they add to a room. They seem to integrate better into other decor themes than the foam diffusers. It's why I suggested the exposed wood look.
> 
> ...


I have only done the wood frame thing but they look good to my eye. I have seen photos of exposed wood diffusers and the generally look great! I am starting to think drift wood from the ocean cut square on the back might be absolutely cool. Something about found objects and all. Not sure about the rules for collecting it, however. Not much of it here in North Central Texas, anyway. 

Yes, Jeanine enjoyed the rug shopping quite a bit. Nice to be able to include her!

Here is the "behind the ears" diffuser on the wall. Note that I need to spray the burlap with a little water and it will shrink up tight (or so the theory goes)!


----------



## InfernoSTi (Oct 31, 2010)

dguarnaccia said:


> John,
> 
> One thing you can do it buy tube shaped insulation and stuff it with normal insulation. I use the 16 inch diameter tubes in my room, and they work well...you can buy em from local building supply shops. I used this stuff from Knauf http://www.knaufusa.com/products/co...t_insulation/1000°_pipe_insulation_ecose.aspx
> 
> ...


Those look outstanding. I have some 10" cardboard tubes stuffed with the R-13 and I think I liked it better in the plastic bag. I'm not sure if it is the depth or the cardboard, but it sure is a lot easier to explained the tubes over the bags of insulation. I need to take a closer look at those 16" rockwool tubes...the would be easily covered with cloth of some kind, as well. Thank you for the excellent tip!

John


----------



## Steve_Vai_rules (Jun 22, 2010)

another thing you can try is if you dont have an exterior or solid core door you (i.e. it's a hollow core door) can use sand or expanding foam to give it more mass and make it more solid/less resonant. foam is good so you dont have to worry about reinforcing the door jam/stronger hinges/etc like you do with the sand. its a cheap tweak but works well. have done that to some random interior hollow core doors on bathrooms and bedrooms in my house and it did help to create more privacy for those rooms.

Matt


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> I have only done the wood frame thing but they look good to my eye. I have seen photos of exposed wood diffusers and the generally look great! I am starting to think drift wood from the ocean cut square on the back might be absolutely cool. Something about found objects and all. Not sure about the rules for collecting it, however. Not much of it here in North Central Texas, anyway.
> 
> Yes, Jeanine enjoyed the rug shopping quite a bit. Nice to be able to include her!
> 
> Here is the "behind the ears" diffuser on the wall. Note that I need to spray the burlap with a little water and it will shrink up tight (or so the theory goes)!


i like the look of the burlap, very vintage speaker cool.

lusone:


Matt


----------



## InfernoSTi (Oct 31, 2010)

Just a quick update: I'm listening to my Bottlehead Quickie pre-amp (still need to finish up the constant power circuit so I'm just using a set of resistors where that would go). Very clean and clear with lots more gain than I thought it would have. It's the red thing in the middle of my DIY SPUD amp and my Decware 1st gen pre amp!

Money well spent and a great "first" project if you have never built any electronics before. You will enjoy the process and the product if you want to learn to build stuff yourself!

John


----------



## InfernoSTi (Oct 31, 2010)

*2A3 Amp Build*

Between now and the Sunday after Thanksgiving, I hope to build my Bottlehead 2A3 Stereomour amp. I've got a good jump on this a few evenings this week (as well as some today). Here is the current state of affairs with the hardware installed and the power supply business finished up. I'd say I'm halfway there at this point!

John


----------



## skeeter99 (Jan 24, 2007)

Dang that looks cool! I'm sure I missed it but do you have any info on the amp?


----------



## InfernoSTi (Oct 31, 2010)

Thanks! It is the new Bottlehead kit that just came out. It can be run with either 2A3 or 45 tubes, but you have a couple of parts you need to switch to do one vs. the other. I suppose you could run the 2A3s in one built for a 45, but you would only see half the normal output of a 2A3, so why do that?

Power 2A3 - 3.5 Watts, 45 - 1.75 Watts
Hum typically 1 mV RMS, depending upon the output tube used
Bandwidth: -1dB at 20Hz, -3dB at 50kHz

The kit is pretty good...excellent instructions, everything fits, the parts are clear as to what they are, and the build is logical. On the other hand, it is a lot of parts for such a simple design. The only thing I have done "custom" is I painted the tin colored bell housing for the power transformer satin black. The tin had a bit of an oxidized look I didn't like. 

I plan on running NOS RCA 2A3s in it once it gets burned in. It is an enjoyable build partially because I'm not in a hurry and partially because there is a lot of room to work in...very few tight spaces!

John


----------



## skeeter99 (Jan 24, 2007)

Very interesting. Never built an amp before but it looks like fun


----------



## django1 (Jan 28, 2009)

3.5 watts? I know that is enough but it doesn't sound like enough...


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> 3.5 watts? I know that is enough but it doesn't sound like enough...


Hahaha! I know, right? The whole idea with SET tube amps is that first "magic" watt of power. And I suppose this is true for any amp (at least for 2 channel music). From the First Watt's (a high end solid state amplifier for stereo only) home page:



Nelson Pass of First Watt said:


> Dick Olsher famously remarked that “The first watt is the most important watt.” This sentiment has also been expressed by others as “Who cares what an amplifier sounds like at 500 watts if it sounds like **** at one watt?”
> 
> Small amplifiers have a number of advantages over “big iron” in that very high quality can be achieved with simple Class A circuits using little or no feedback.
> 
> With oddball characteristics and output power ratings of 25 watts or less, First Watt is not for most people. If you have efficient loudspeakers, listen at reasonable levels and are obsessed about subjective performance, then you probably have come to the right place.


My OB speakers are 96 db and my room is small, so with one watt, they get plenty loud. Interestingly, my DIY SPUD amp is 3 watts and I never get it past 12 o'clock on the dial. Did I mention I'm using a pre amp that adds some gain on the front end? Also, bass is the big hog with power, so I bi-amp with two Rythmik amps (370 watts each) set up to run in true stereo. This setup gives you the best of both worlds, and using the pre amp allows master volume control for the three amps. 

Putting the set up together has been quite the learning experience: perhaps that has been as much fun as the end product! I feel like I'm moving past newbie and into knowledgable pretty quickly at this point!

John


----------



## InfernoSTi (Oct 31, 2010)

Well, I finished up the Bottlehead Stereomour 2A3 amp last night. My resistance checks were all spot on and my voltage checks were all within design tolerances so I plugged in my OB Hawthorne Duets and OH WOW!!! 

The Stereomour has a rich, smooth character, even before burn in. Music has nice detail, good spatial placement/soundstage, silky highs, and buttery mids. The amp is nice and quiet: hum is only 0.28 mA on the right channel and 0.33 mA on the left.

As far as the kit? They provide excellent instructions with only a few simple to catch errors (minor typo stuff), the build is easy enough with only a few hard sections (the benefits of such a large area to work in), and 30 feet of wire (that is a lot of 2" point to point connections)! All in all, I put mine together in about 24 hours over about a week (I still want to work up a nice case, so figure the total will go up to 30 hours, tops). I'm not the fastest amp builder, so YMMV. 

The sound of this amp is well worth $750 and 30 hours time! I can't wait to hear this amp after about 100 hours of burn in...

John


----------



## skeeter99 (Jan 24, 2007)

Well it sure looks nice! The work looks top notch, congrats!!


----------



## InfernoSTi (Oct 31, 2010)

skeeter99 said:


> Well it sure looks nice! The work looks top notch, congrats!!


Thank you very much! 

John


----------



## PhenomeNhan (Mar 4, 2008)

Wow! Very nice work, John!


----------



## Jason Brent (Mar 28, 2009)

:smoke1:


----------



## django1 (Jan 28, 2009)

I'm impressed, nice job!


----------



## InfernoSTi (Oct 31, 2010)

Hey guys, thanks for the kind words! The kit is seriously easy to build, so I can't really take too much credit other than putting the effort in to start/finish it. 

Nhan, perhaps sometime during the busy holidays you can come over and take a "critical" listen to the system? Since your little GTG I've become obsessed with better source material (probably TwoTwo's...Michael's...fault with those hi-res Blu-ray concerts!) and smoother tube amps (definitely your fault with that GORGEOUS amp you have!). 

John


----------



## PhenomeNhan (Mar 4, 2008)

Sounds like a good plan to me, John. Thanks for the invite. I'll have lots of free time staring next month, so just let me know when


----------



## InfernoSTi (Oct 31, 2010)

That's great, Nhan! Looking forward to it.

John


----------



## InfernoSTi (Oct 31, 2010)

This weekend I stripped my SPUD amp down to the chassis and rebuilt it with the following upgrades: silver plated copper teflon wire throughout (except for the shielded wire which is silver plated kapton); modified the grounding scheme to be a star ground, not a buss ground; added bypass caps in both the power supply and the cathode resistor bypass (found a nice polystyrene 0.1uF NOS cap for the cathode bypass. It sounds much nicer now...smooth and detailed with a much greater upper end extension. Well worth the extra effort!

John

Stripped and starting to rewire:









Stuffed full of big caps!


----------



## django1 (Jan 28, 2009)

Stuffed full indeed. You need a bigger enclosure now...:eyebrows:


----------



## skeeter99 (Jan 24, 2007)

django1 said:


> Stuffed full indeed. You need a bigger enclosure now...:eyebrows:


Werd, that just looks scary to my untrained eyes!


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> Stuffed full indeed. You need a bigger enclosure now...:eyebrows:





skeeter99 said:


> Werd, that just looks scary to my untrained eyes!


Hahaha, yes, I hear you. The photo makes it look a bit more of a rats nest than it really is...the wire holds it's shape in three dimensions, so stuff that looks right on top of each other may have 1/2" clearance vertically. Also, I added a DPDT switch to the cathode circuit to test different configurations A-B, so I have two different cathode resistor bypass circuits in there. In reality, it is much more open than my Bottlehead 2A3 amp in stock configuration. 

The big orange cap is a Jantzen Superior Z-cap in the power supply. On the A circuit, the two big black ones in the middle are the "Fastcap" polystyrene caps on the cathode resistor bypass (they are actually bypassing a 10uF cap and a 22uF cap). On the B circuit, I have a single shared resistor and no caps. I have ordered a set of LEDs to swap out instead of the shared resistor. 

A guy on a different forum is doing some experiments and I am following some of them to give a "second opinion" if you will. 

And I was actually thinking of how nice an extra inch or two in each direction would be for everything. 

John


----------



## InfernoSTi (Oct 31, 2010)

Given the improvements the bypass caps made in the SPUD amp, I decided to try them out in the BH Stereomour 2A3 amp, and I'm really pleased with the results. 

First, I took out the two 3.3uF Solen caps and replaced them with Auricaps in a "super cap" configuration consisting of the base 3.3uF Auricap bypassed with 0.33uF and 0.022uF Auricaps. Second, I bypassed the stock Panasonic Metal Film 0.1uF coupling caps with 0.022uF Auricap caps.

The improvements did have a very nice affect on the sound quality of the Stereomour 2A3: the overall clarity increased, the extension of the upper end was improved, and the width and placement of the soundstage increased a little bit. It seems that there is both a tonal improvement and that the soundstage is being better handled to create the clarity, and the extension can really be heard in the a longer "splash" decay of cymbals.

I'm very happy with the results which didn't change the overall sound of the amp as much as make things I liked about the amp a bit better!

Here is an adequate photo (you can only see three of the four new caps), but it shows the general idea of what I did:










Cheers, John


----------



## django1 (Jan 28, 2009)

Wow! reminds me of one of those old b movie horror flicks: "The Caps that took over the world". They seem to be growing and about to take over your...amp...


----------



## InfernoSTi (Oct 31, 2010)

I am a convert to the school of bypassed caps! 

I didn't understand how this worked until someone explained that the main cap will handle the biggest fluctuations, typically bass notes, and when it is sized to handle those well, rarely would it be able to handle the tiny transients in the mid and upper end at the same time. They explained that the "order of magnitude" rule applied so that the first bypass is 1/10th the uF of the main cap and that handles the mid range, while the second bypass is 1/100th the uF main cap and that handles the upper range.

I have to say the change is noticeable for the better in the two applications I have tried them in. On the Stereomour, I also upgraded the main cap from a Solen to an Auricap, so that has it's own effect, too.

John


----------



## django1 (Jan 28, 2009)

Thanks for sharing that. I ordered some of those fancy(expensive!) bypass caps for my N3 crossovers and sort of wonder why I would want to bypass those already kind of expensive caps...


----------



## InfernoSTi (Oct 31, 2010)

I know this is one of those topics like "which interconnect is better" or whatnot. 

Some folks don't like the sound compared to a very nice high quality cap. In my searching, I found folks willing to spend the money for V-caps didn't feel the need for bypassing. For the rest of us not wanting to spend $100 per cap, a nice bypass of a cap you generally like sounds good. Some folks even prefer to mix and match to taylor the sound (a nice round sounding big cap with a highly detailed bypass cap or whatnot).

All I know is (1) I can hear a big difference between using them and not and (2) I prefer them in rather than out (in my particular setup and location). YMMV as they say! 

Good luck with your project and post the results, please? I would like to hear about them...I don't know a thing about crossovers. Photos would be cool.

John


----------



## PhenomeNhan (Mar 4, 2008)

Can't wait to see (and hear) all this stuff. I'll carry my LS6s over for a comparison


----------



## InfernoSTi (Oct 31, 2010)

PhenomeNhan said:


> Can't wait to see (and hear) all this stuff. I'll carry my LS6s over for a comparison


Now that just wouldn't be a fair comparison: those things are monsters (and sound great)! And I'm not sure what you drive, but in my car that would involve a saw and two trips! :biglaugh:


----------



## PhenomeNhan (Mar 4, 2008)

InfernoSTi said:


> Now that just wouldn't be a fair comparison: those things are monsters (and sound great)! And I'm not sure what you drive, but in my car that would involve a saw and two trips! :biglaugh:


I was going to carry them and walk over there


----------



## InfernoSTi (Oct 31, 2010)

PhenomeNhan said:


> I was going to carry them and walk over there


That makes sense. Way too big for me to carry, but judging by this photo of you tossing a stick for your dog at the last GTG, they shouldn't be much trouble for you, Nhan.... :stirthepot:


----------



## django1 (Jan 28, 2009)

Lol. Vietnamese kilt?


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> Lol. Vietnamese kilt?


Yep. Traditional...


----------



## InfernoSTi (Oct 31, 2010)

Oh man, Nhan drank all my beer... 

:toast:


----------



## skeeter99 (Jan 24, 2007)

InfernoSTi said:


> Oh man, Nhan drank all my beer...
> 
> :toast:


Good thing I'm taking him to a brewery in January when he comes up, can't drink all the beer there :neener:


----------



## PhenomeNhan (Mar 4, 2008)

django1 said:


> Lol. Vietnamese kilt?


My favorite is the blue one


----------



## PhenomeNhan (Mar 4, 2008)

InfernoSTi said:


> Oh man, Nhan drank all my beer...
> 
> :toast:


Thanks for offering up your beer collection, John! Very good stuff. Thanks for building up my image, but too many people on the forums have seen my drinking prowess (or lack thereof)


----------



## PhenomeNhan (Mar 4, 2008)

skeeter99 said:


> Good thing I'm taking him to a brewery in January when he comes up, can't drink all the beer there :neener:


I might do some Jack or Vodka and coke in between


----------



## PhenomeNhan (Mar 4, 2008)

For a moment there, I forgot what this thread was about. Thanks for having me over to listen to your DIY work-in-progress, John. You've done some very good work there. Everything sounded very good. Let me know when you are able to sneak the system into the family room


----------



## InfernoSTi (Oct 31, 2010)

PhenomeNhan said:


> For a moment there, I forgot what this thread was about. Thanks for having me over to listen to your DIY work-in-progress, John. You've done some very good work there. Everything sounded very good. Let me know when you are able to sneak the system into the family room


I'm really pleased to have had you over. The small room really is a compromise, but I have tried to make the most of it. Oh, and you will be here to help move it into (and back out of) the main room! How's that for an invitation: hey, come on over and take a listen...do you mind carrying this amp, please, etc....

I've come a long way from January...see my first post (below)! It is interesting to read in the context of our conversation about how do we really know what we like in audio. It is surprising how much one can learn in a year thanks to fine folks such as at Chase HT forum, the first forum I felt comfortable joining twelve months ago. Nhan, I specifically appreciate your encouragement over the last year very much!

John



InfernoSTi said:


> Hi! I'm a newbie to both this forum and to the audio forums.
> 
> After lurking for a while reading a ton of different forums on small amps and mini monitor speakers, I decided to jump in with both feet: you can't learn what you like by reading what someone else likes, right?
> 
> ...


----------



## InfernoSTi (Oct 31, 2010)

PhenomeNhan said:


> Thanks for offering up your beer collection, John! Very good stuff. Thanks for building up my image, but too many people on the forums have seen my drinking prowess (or lack thereof)


Well, the hyperbole may be a tiny bit exaggerated...


----------



## django1 (Jan 28, 2009)

My first forum was over at av123, probably three years ago. Before that in 25 years I bought one avr, two speakers and cd/dvd player. It sounded bad and I didn't listen to it. Since joining a forum I have bought 2 pairs of speakers (upgraded the crossovers in one pair and added no rez), one center speaker ( I upgraded the crossover and added no rez), a pair of DIY speakers, one sub, one DIY sub,two 707 dacs, 2 dvd players, one cd player, 6 amps:dizzy: (upgraded the caps in one), one pre amp, one headphone amp, one pair of head phones. 

That's all ...


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> My first forum was over at av123, probably three years ago. Before that in 25 years I bought one avr, two speakers and cd/dvd player. It sounded bad and I didn't listen to it. Since joining a forum I have bought 2 pairs of speakers (upgraded the crossovers in one pair and added no rez), one center speaker ( I upgraded the crossover and added no rez), a pair of DIY speakers, one sub, one DIY sub,two 707 dacs, 2 dvd players, one cd player, 6 amps:dizzy: (upgraded the caps in one), one pre amp, one headphone amp, one pair of head phones.
> 
> That's all ...


That is great! Six amps used to sound crazy to me but now I'm like, well, that makes sense! 

You were one of the first to welcome me to this forum, as I recall, and recommended I consider an off-board DAC: great advice that I followed and have never looked back! Sharing knowledge in a friendly manner and avoiding snark are the real test of character, as far as I'm concerned! 

The coming new year makes me look back fondly at 2010...a year that might otherwise be pretty bleak has been (affordably) exciting for many of us!


----------



## django1 (Jan 28, 2009)

I kind of wish I could have gotten where I am now straight away without buying all the other stuff that isn't being used much. I would have saved some $ and the spousal unit would think I was slightly less nuts...


----------



## dvenardos (Sep 27, 2008)

django1 said:


> ... and the spousal unit would think I was slightly less nuts...


Good luck on that one. oke:


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> I kind of wish I could have gotten where I am now straight away without buying all the other stuff that isn't being used much.


True, but that's where all the fun lies....



django1 said:


> and the spousal unit would think I was slightly less nuts...


Now if you are honest with yourself, you would have to ask would it really have made a difference? Hahaha...


----------



## django1 (Jan 28, 2009)

Don actually has me thinking about getting one of those Virtue amps now...:dizzy:


----------



## django1 (Jan 28, 2009)

InfernoSTi said:


> True, but that's where all the fun lies....
> 
> 
> Now if you are honest with yourself, you would have to ask would it really have made a difference? Hahaha...


What was this thread actually about anyway?:biglaugh:


----------



## Steve_Vai_rules (Jun 22, 2010)

this thread needs more pics...

(not sure of what but it needs pics). :woo:


Matt


----------



## tesseract (Aug 9, 2010)

Steve_vai_rules said:


> this thread needs more pics...


Ok...
View attachment 2239


----------



## InfernoSTi (Oct 31, 2010)

Steve_vai_rules said:


> this thread needs more pics...
> 
> (not sure of what but it needs pics). :woo:
> 
> ...


Hey Matt...there are photos...just a looooooong way back! I'm assuming you missed those so this post should catch you up to speed! 

Built my Bottlehead Stereomour 2A3 amp: 
















And already added bypass caps (Auricaps):










Stripped down and rebuilt my SPUD amp with silver plated copper/teflon wire and upgraded components:
















And now I'm working on a custom diy tube buffer with a volume pot using a 6N1P buffer tube, a CRC heater supply, a choke in the B+ power supply, and bypassed caps in the main section. I am doing the whole thing from scratch (punching holes in the top plate, etc). The schematic is unique based on combining sections from several sources (with a ton of help from a buddy who knows his stuff).

How about you, Matt? Any diy going on?

John


----------



## Steve_Vai_rules (Jun 22, 2010)

That looks great! I really need to get myself into some diy amp building, just because i already have a lab so to speak (my office/IT lab where all my soldering gear is) and building amps sure takes up a lot less space then speakers.

actually I am working on something of my own design, a 4 way with accuton tweeter, midrange and mid-bass and a rythmik servo sub. thanks to some family friends who are all sailboat owners on the coast i have had some pretty substantial experience with laying up fiberglass and carbonfiber on a few quite nice boats. I am planning on building the cabs using carbon fiber. After lots of research i have decided that instead of building a passive crossover I am going to go with an active crossover.

I figure I will use this as both studio monitors and for 2 channel use. My fiancee and I are currently designing our new home and i have space for a largish 2 channel room/meditation/yoga room (she's all new age and such). so I figure that a horn and an open baffle won't be as necessary for the room which will be designed with 2-channel listening in mind.

I've attached an image of my drawing of the external layout of the cab. The cabinet will be made out of 5 parts then epoxied together. "thumbsup:

I don't have much else to post about it as I am trying to work out the materials engineering of the cabinet and how I will construct the necessary molds/how I will be laying things up. I am spending lots of time detailing all these steps on paper and making sure everything works in theory before I start building the various molds (will likely be about 12 to 15 molds). 

I am fairly close to having everything done on paper and will be ready to start building.

ambitious yes, but it's how I roll. 

Matt


----------



## InfernoSTi (Oct 31, 2010)

Matt,

That really is ambitious, but I have no doubt you will put together a fantastic project (more than just speakers). I think you will really enjoy having an active crossover management setup, too. Do your best to keep that system as simple as possible, of course! 

In the meantime, you should build an amp just for fun (especially with no GIZMO replacement on tap).

John



Steve_vai_rules said:


> That looks great! I really need to get myself into some diy amp building, just because i already have a lab so to speak (my office/IT lab where all my soldering gear is) and building amps sure takes up a lot less space then speakers.
> 
> actually I am working on something of my own design, a 4 way with accuton tweeter, midrange and mid-bass and a rythmik servo sub. thanks to some family friends who are all sailboat owners on the coast i have had some pretty substantial experience with laying up fiberglass and carbonfiber on a few quite nice boats. I am planning on building the cabs using carbon fiber. After lots of research i have decided that instead of building a passive crossover I am going to go with an active crossover.
> 
> ...


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Matt,
> 
> That really is ambitious, but I have no doubt you will put together a fantastic project (more than just speakers). I think you will really enjoy having an active crossover management setup, too. Do your best to keep that system as simple as possible, of course!
> 
> ...


I'm looking forward to the active crossover/room correction/eq. It opens up so many fields of tweaking too, i can build my own 8 channel dac (hopefully to improve on the deqx's built in dac) also i will need 6 channels of amplification and i am seriously considering going diy for all 6 channels. tubes for the midrange and tweeters and solidstate for the midbass.

as for simple, well, it really won't be simple, 6 channels of amplification and all.. lol. but i will only be feeding the DEQX from two sources a good quality cd/sacd player that will act as a transport, and a music server. i will probably find myself a good turn table at some point, but i really just dont listen to vinyl often nor do I have a lot.

the point of this project is to just make the best speaker i can. but without resorting to horns or wave guides or open baffles.

i was considering getting a gizmo but with the import fees/taxes/shipping/etc. it would cost as much as some kits.. so i was trying to figure out where i wanted to go with it... but now that the gizmo is gone that sort of clears it up for me.. lol

what do you have next on your list?

Matt


----------



## InfernoSTi (Oct 31, 2010)

Matt,

The active crossover is really appealing and, to a certain degree, by default I subscribe to the basic philosophy as I use tubes for the mids and tweeters and bi-amp with two Rythmik plate amps for the bass. While not completely active, I enjoy the ability to manage separate volume and crossover settings: to a very great degree it is like a very sophisticated tone control. You are right, the tweaking by album to get that "just right" sound is very enjoyable! I can't wait to watch your project come together. Post photos and write-ups of your progress, please?

I'm building a custom DIY tube buffer/passive pre amp. I have a custom schematic that a friend who designs amps helped me put together based on the tube type, etc. It is pretty cool to have something unique that isn't based even on a kit. I have all the parts sourced and sitting and just need to sit down and put it all together. I'm hoping this coming weekend to make some good progress. 

After that, I want to actually design my own tube amp from the selection of a tube on. This is ambitious, as well, but my friend who designs amps is very kind to let me lay things out, explain my logic, and then he reviews/corrects/explains. By trying first and stating why, he really is able to see where I am in my understanding. There is a lot of research in between steps. 

And this Spring, I want to redo my baffles completely based on what I have learned the first time. I want to focus on vibration control (dampening, bracing, mass, and decoupling). This seems easy because we always think of speakers as boxes but it is a real challenge with a flat baffle that is prone to sympathetic vibration. I have been reading a lot about materials that convert motion to heat (dampening, adding mass) and ways to address second moment of inertia (the I-beam concept), as well as ways to decouple the drivers from the baffle. 

Cheers, John


----------



## django1 (Jan 28, 2009)

InfernoSTi said:


> Matt,
> 
> The active crossover is really appealing and, to a certain degree, by default I subscribe to the basic philosophy as I use tubes for the mids and tweeters and bi-amp with two Rythmik plate amps for the bass. While not completely active, I enjoy the ability to manage separate volume and crossover settings: to a very great degree it is like a very sophisticated tone control. You are right, the tweaking by album to get that "just right" sound is very enjoyable! I can't wait to watch your project come together. Post photos and write-ups of your progress, please?
> 
> ...


Sounds like I'll be buying your stuff soon...


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> Matt,
> 
> The active crossover is really appealing and, to a certain degree, by default I subscribe to the basic philosophy as I use tubes for the mids and tweeters and bi-amp with two Rythmik plate amps for the bass. While not completely active, I enjoy the ability to manage separate volume and crossover settings: to a very great degree it is like a very sophisticated tone control. You are right, the tweaking by album to get that "just right" sound is very enjoyable! I can't wait to watch your project come together. Post photos and write-ups of your progress, please?
> 
> ...


sweeeeeeeeeeeeeeeeeeeeeet!!!!!!!!!!! :rock:


I too have been looking into materials that are flexible yet dense. Sounds like we can share some notes  

the way i am tackling vibration is by using constrained layer damping. the cabs are going to be made of carbon fiber with a dense yet flexible epoxy resin. I also have some ideas on mounting drivers on a baffle that isolate the drivers from the baffle. It seems to me that mounting drivers directly to the baffle will cause the baffle to vibrate both from the movement of the cones of the driver but also due to acoustic resonances. Isolating the driver from the baffle will lower those sympathetic resonances. In the case of my cabinet the baffle is going to be 4 to 4 1/2 inches thick with two layers of 10-15mm thick carbon fiber with a custom flexible resin between so i am not so worried about the baffle becoming excited, though i will do something about the side mounted woofer.

im excited to see how your projects pan out! and yes i will do a writeup and with pictures. 


Matt


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> Sounds like I'll be buying your stuff soon...


Heavens no...just having some fun the "inexpensive" way!!!


----------



## InfernoSTi (Oct 31, 2010)

Steve_vai_rules said:


> sweeeeeeeeeeeeeeeeeeeeeet!!!!!!!!!!! :rock:
> 
> 
> I too have been looking into materials that are flexible yet dense. Sounds like we can share some notes
> ...


Carbon fiber is an excellent material in that it naturally does not conduct vibration well. I would love to see your project and maybe learn a little about carbon fiber as I don't know the first thing about working with it.

Isolation = decoupling and is a very good technique. Constrained layer damping is excellent, too. You have given this a lot of thought already. 

The thing I would add is that mass will go a long way to taming vibration, as well. The bass really vibrates at too great a level to not address, and a bracing that can tame the larger motions is important, too. I believe I will use some form of a main baffle with the drivers attached to a mounting plate that can be decoupled to one degree or another from the front baffle. I would like to frame the main baffle with a small box to which I would fill with sand to address the bracing and create mass. I would also treat the surface of the baffle and the mounting plates with an adhesive damping material, which would reduce resonance and help decouple. 

While all this seems a bit crude and simple, my thought is that the cumulative affect will be significant compared to my current baffle. 

Here is a product that I am looking at trying out: part number 9709T26

http://www.mcmaster.com/#9709t18/=adopmx

John


----------



## Steve_Vai_rules (Jun 22, 2010)

im also looking at various laminate materials to add to the carbon fiber to help break up resonances even more. and example being a layer of carbon fiber and then a layer of kevlar then a layer of carbon fiber and perhaps a thin layer of rohacell (a kind of foam that is used often in the aerospace industry like in wings and helicopter rotors.). even laying strips of carbon fiber or kevlar in different directions and orientations, so that the weave of the fabric changes in direction.

carbon fiber is pretty cool to work with, and you can make anything with it. some carbon fiber enclosures for a set of mono-blocks would be totally sweet. CF is also fairly easy to work with. get some resin with a bit longer of a working time and just lay down your sheets. there are quite a few vids on youtube of CF how to's.

I am looking to add mass through the flexible resin that will fill the chamber between the two laminated sheets of carbon fiber. there are mineral additives that can up the density and therefore the mass. I have a rough estimate of the mass of the cabinets being around 250-280lbs. I'm also going to use granite bases to help change the resonance qualities of the speakers and help keep resonances from reaching the floor. 

I am still working out the bracing scheme, i likely will do a matrix style bracing but i need to do some tests first to really see how important bracing will be with these cabinets. There will be some bracing but i just am unsure how much quite yet. that's really the last thing i need to figure out before i can start building the prototype box.

how big are you planning on making the baffles? even just adding to the size of the baffle can add quite a lot off mass especially if you are gong to have thicker baffles. I also thick that choosing to laminate various materials together can really improve those resonance characteristics. say a layer of maple ply then birch ply then mdf.

Another way of adding mass is using concrete or just cement. it's pretty good at absorbing vibration it's nice and dense and will add tonnes of mass to where ever you add it. **** even a base made out of concrete can make some big differences in how things will behave especially if the speaker cab is solidly connected to it.

I'm really excited to see your next OB's. are you going to use the same drivers and xo that you currently have or are you starting completely fresh?

Matt


----------



## InfernoSTi (Oct 31, 2010)

Matt, 

I can't wait to see your project unfold. I will learn so much just seeing your process. I really like the idea of layers of different materials for dampening. 

I am still pondering the design: I want to use the same basic drivers but am considering adding a second 15" bass augmenter. I want to move air easily at (relatively) low volumes and feel this will do it. If so, the final baffle will be approximately 20" x 48" each. Of course, they are quite thin, so while that is huge, they are not like Klipschhorns or something. I may chicken out and stick with the current size (20" x 36") or so. 

Here are a couple of photos of my 6N1P tube buffer/passive pre amp:



















It is a complete "scratch build" project, my first not using a kit. I learned a lot about how to layout a chassis, how to drill/punch the proper (and sometimes not so proper) holes, and of course the schematic was unique to this project, so sourcing parts was a learning experience, too. 

I'm very happy with the sonics (but that may be a bit of the proud poppa thing). Anyway, it is safe to say I'm enjoying it very much!

John


----------



## InfernoSTi (Oct 31, 2010)

Just added two more OB bass augmenters. So now I have four 15" woofers powered by two Rythmik 370 plate amps to go with my two 10" mid-woofers and two compression horn tweeters. Wow!!! I'm very pleased....


----------



## django1 (Jan 28, 2009)

InfernoSTi said:


> Just added two more OB bass augmenters. So now I have four 15" woofers powered by two Rythmik 370 plate amps to go with my two 10" mid-woofers and two compression horn tweeters. Wow!!! I'm very pleased....


Cool. I'd love to hear it... 

What does your wife think of the bass?


----------



## Steve_Vai_rules (Jun 22, 2010)

i bet that is some room filling clean clear bass! :woo:

it actually looks kinda small but then i realize that those are 15" woofers and that the 4 of them are taking up 3/4 of your room! lol

I am starting the CAD lay out of the molds that I will use. Because of the complex shape I will have to use multipart molds. So that means I will have two or 3 molds and bolt them together to form the shape. I think in total I will 10 molds that I need to work with and also build. So that means I likely will have to construct about 6 positive molds in order to get the desired shape of the speakers and transfer that shape to the negative molds. I am unsure of what I will use for the negative molds, the positive molds will likely be MDF and bondo. I could use carbon fiber for the negative molds but i likely would only do that if i was planning on putting them into production (carbon fiber negative molds are what are used when manufacturing carbon fiber parts) i could use fiber glass, although fiber glass can often shrink, so i would have to be careful there. I could use a plaster type cast mold as well or even an epoxy mold, but again there is the potential for shrinkage with some epoxy molds. I will do a detailed write up about the whole design and construction when I am further along in the build. 


Matt


----------



## InfernoSTi (Oct 31, 2010)

django1 said:


> Cool. I'd love to hear it...


Come on down (but pack warm, were in the middle of a cold front: I had to wear sweat pants with my tee shirt to get the paper this morning)!



django1 said:


> What does your wife think of the bass?


This is the scary part, thanks for asking. I bought them "with baffles" used and they arrived in a pretty large box weighing 65 lbs. I got home from work and she motioned me to the front porch when I walked in but other than that hasn't said a single word. She is cool with the audio thing in general, however, so I'm sure we will discuss her getting a new sofa or whatever she has been looking at for elsewhere in the house later this weekend!




Steve_vai_rules said:


> i bet that is some room filling clean clear bass! :woo:
> 
> it actually looks kinda small but then i realize that those are 15" woofers and that the 4 of them are taking up 3/4 of your room! lol


Matt, the sound, to my ears, is very flat, not boomy or exaggerated at all. I'm not smart enough to fully understand if having a pair of 15" dipole woofers for each speaker (i.e. in stereo) avoids room modes or has a faster decay, or what, but there is a lot of discussion of this with the Linkwitz Laps and other sources that have fully developed dipole subwoofers many people like. 



Linkwitz Lab said:


> "This correlates strongly with the impression that bass reproduced by a pair of dipole woofers is more articulate and thus more realistic of the recorded source." http://www.linkwitzlab.com/Woofer%20accuracy.rtf


I am hearing bass that I never heard before, but the really cool thing is the soundstage across the whole range is smoother. The extra Augies have helped to blend my two point source mid/horns seamlessly. In a small room such as I have, there isn't distance to blend with distance (you know, sitting a proper distance from the speaker). I wasn't expecting that part of the sound quality result at all. 

I have a great Rush drum solo recording (a near mic'd recording from Snakes and Ladders Live) that is amazing to listen to now...to me, each drum kit piece has it's own place in the soundstage. It blows me away.

OK, I'm loving it!



Steve_vai_rules said:


> I am starting the CAD lay out of the molds that I will use. Because of the complex shape I will have to use multipart molds. So that means I will have two or 3 molds and bolt them together to form the shape.
> 
> I think in total I will 10 molds that I need to work with and also build. So that means I likely will have to construct about 6 positive molds in order to get the desired shape of the speakers and transfer that shape to the negative molds.
> 
> ...


This is so cool and so far out of my league. I am really excited for this project. 

John


----------



## django1 (Jan 28, 2009)

InfernoSTi said:


> Come on down (but pack warm, were in the middle of a cold front: I had to wear sweat pants with my tee shirt to get the paper this morning)!
> 
> John


Wow! That sounds scary.


----------



## Steve_Vai_rules (Jun 22, 2010)

InfernoSTi said:


> This is so cool and so far out of my league. I am really excited for this project.
> 
> John


glad to hear that the bass has really opened up! i haven't had any experience with open baffle bass, so I am going to have to try that at some point. That could be a really quick interim project while I am working on other stuff. 

I was going to attach a pdf detailing how to work with carbon fiber. it's a must read for anyone who wants to work with CF. I think everyone should build something out of carbon fiber, it just looks so **** cool. I will try to upload it somewhere else and link to it here.


Matt


----------



## InfernoSTi (Oct 31, 2010)

Took me a while to find this thread on the new forum but it's there and I appreciate not losing the conversation between a few of us...I go back and reread posts from Matt and others pretty regularly. 

Congrats on the new forum Craig et al in the Chase family!!!

John


----------



## 1Michael (Nov 2, 2006)

I found that placing the driver closer to the bottom of the baffle around 2 inches helped the bass significantly.


----------



## InfernoSTi (Oct 31, 2010)

Hey, Michael, thank you! Sorry to have to ask, but what is your setup? 

Since you commented, I am redoing my OB speakers and the current plan calls for satellite baffles with twin bass augmenter baffles below. Here is the basic theme (as drawn up for me by DanG):

The upper baffle holds a 10" mid-woofer with a center firing Comp Driver tweeter. The lower baffle holds two 15" woofers. They would be quite low, perhaps 2" or so. Good to hear you had better results from the lower position!

Thanks, John


----------

