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post #1 of 603 Old 08-02-2009, 07:07 PM - Thread Starter
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Hi guys. Thought I'd share a bit of info on two speaker projects I've been working on. I'm pretty excited about both, and although they are pretty different conceptually, they are actually have similar design criteria, they just go about it different ways. The first is an update to my Bose Buster design from a couple years ago. That was my first design ever and while fun, it was really a budget design that was not very refined. The BB V2 is much more performance orientated. While high value was important, this more of a "best sound quality from the smallest possible formfactor" speaker. There will be three variants: MTM, TM, and fullrange, with both BSC and on-wall versions. I wanted these to not only sound excellent, but hang right next to a nice plasma tv and not look of out of place.

The midrange is based on the excellent Fountek FR88-EX. The tweeter will be the Vifa DQ25. Both of these are very low distortion designs with the Fountek having one of the cleanest midranges I've seen in this size driver.

The MTM will be a third order Butterworth design for the smoothest polar response, especially important for off axis listeners watching a movie. The TM will be either second order Linkwitz-Riley or third order Butterworth, pending some research into the sound differences and the the ability for these drivers to pull of the difficult LR2 slopes.

Of course bass is an integral part of this design and while a single small sub will be an option, the real deal will be three subs, distributed about the room for the smoothest response from 30-200hz. I'll be adding a walkthrough using something like ARTA or TrueRTA so anyone with a microphone can follow along and get optimize the response and sub/satellite integration. The concepts behind this were inspired by Welti/Harman and Earl Geddes. I hope and expect the optimized three sub version to take the whole system to a very high level. Certainly higher than one would expect given the small form factor. The subs will not just be an afterthought, but the entire sub/satellite integration will be optimized together.

Now the subs themselves leave open many options, depending on what the builder is trying to accomplish and how they are willing to spend. I'll list the criteria that will govern sub selection and people can choose whatever fits that criteria. Given some effort measuring the in room response we can integrate the different choices in subs quite well. For myself I decided I was going to use three Silverflute 8" 8 ohm woofers. Sure there are better woofers, but the price to performance is very good for these. They have smooth response, easily able to cross at 200hz to the satellites, decent distortion in the bass, good sensitivity, and require a small box. Another thing that helped me decide on these was the availability of the Foster WF-100K amp from Jack Hidley of NHT. This amp and driver combo is a match made in heaven. Perfect amount of power, and low end boost that perfectly matches the natural response of the Silverflute. For example the boost is centered around the same frequency that I'll be tuning the box at (30hz). This means we'll be putting the most power to the driver at the frequencies where it is doing the least work already and driver excursion is a minimum because the port is doing all the work. That is always a good thing! A high pass to protect the driver below tuning and a ton of options to tweak all of these filters make this a perfect amp for this application. I spent $225 and now have three subs that will together will perform at a very high level by leveraging their strengths and working WITH the room, instead of against it.

Again this will be a complete system that is optimized as a whole, and accounts for the room and works with it. Acoustic solutions to acoustic problems as Jon Marsh would say So enough blah blah, here is a pic of the satellites:





The other project is sort of tangent for me into the world of high sensitivity speakers. Some of you may have been following my testing on some drivers for this project and I think we have some solid candidates. The design will be a standmount 2-way, using a 12" woofer mated to a horn loaded compression driver. The intent is to cross these as low as the horn response and CD roll off allow, and where it best matches the directivity of the woofer. Currently it looks like 1200-1300hz is the target.

The woofer will be excellent Eminence Kappalite 3012HO. This driver is a new design from Eminence and is really a high performer. Response is reasonable smooth for this size woofer, and distortion is very clean, particularly IMD. The horn will be a real gem in the QSC PL-000446-GP that only costs $8 and is obviously designed using Geddes' principles. Frequency and impulse response is very smooth and clean. I'll be adding some 30 ppi foam per Geddes that is visually identical to what I had in my actual Geddes waveguides. I expect all the dynamics of PA horns, but without the horn "sound". The CD is still a bit up in the air. I had planned on a B&C DE12 with mylar diaphragm but the DE160 is also being considered. For the first iteration of this speaker price is a concern. I want something that can be built for $600 per pair for the complete speaker, wood and all. The DE160 starts to push that target a bit but may be worth it.

The ability to play loud and clean is obviously a goal, but so is the ability to also be delicate when needed. It should be able to go from Wagner to Chemical Brothers to Diana Krall with equal ease. This became a goal as I was listening to a Led Zeppelin song that perfectly captures what this speaker is all about, No Quarter:




Still pretty raw as the veneer is unfinished and baffle is not yet finished in the black duplicolor textured finish yet.
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post #2 of 603 Old 08-02-2009, 07:43 PM
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The waterfall bubinga is going to look sharp when it is finished. Nice looking speakers on both counts. Can't wait to hear the verdicts on sound quality.
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post #3 of 603 Old 08-02-2009, 08:02 PM
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Who cares what it looks like, How does it sound???

JK, that looks SWEET

Nice job on the corners, looks tricky. What size round over bit are you running?

Regards,
Dan
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post #4 of 603 Old 08-02-2009, 08:47 PM - Thread Starter
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Dan it's a bit off a mix of roundovers. The front baffle is 1 1/4" although I had planned on 1 1/2" but that bit is just too big for my router base until I get around to making a custom one. Saves 1/2" from the baffle width anyway, it's 16 1/2" currently and 25" tall. The corners are done with a 1" roundover and the back panel is 3/4".
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post #5 of 603 Old 08-02-2009, 09:59 PM
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Nice work as always Brandon. On a side note, take a look at this

http://usspeaker.com/images/Beyma-12LW30-size271.gif

I think this driver warrants some investigation.
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post #6 of 603 Old 08-02-2009, 10:04 PM
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Quote:
Originally Posted by augerpro View Post

I want something that can be built for $600 per pair for the complete speaker, wood and all.


I'll take 3 in basic black. Looking forward to seeing how this thing turns out and how it sounds.
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post #7 of 603 Old 08-02-2009, 10:33 PM - Thread Starter
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Tip to anyone reading: never use the duplicolor spray on a hot day in the sun. The spray is almost dried before it hits the wood and came out really fuzzy and the smooth coverage I've come to expect from it kind of sucked. I'll actually be sanding these down this week and spraying them in the shade. I've found 70F seems to be perfect to get that even 200 grit finish that I like so much.

That said I love the small form factor. These are between 3-4" deep depending on the variant! These are really tiny speakers. I had considered updating the BB when the Dayton RS100 came out, but it really is quite a large speaker for what I was looking to do and the box volume would have to be quite large. No wall speakers. Then these Fountek's came out and I thought what the heck I'll buy one and send it to Zaph as he was doing a driver testing session at that time. The response and especially the distortion surprised the hell out of me. Then when I ran the numbers for box size I knew I had the perfect midrange for V2. Both these and the RS100 are 3" but the RS100 is much bigger physically. This Fountek is closer in size to the TangBand W3-1364, but not as tall. I had considered that at one time as it takes a very small box, but I was never enamored of teh response and basically no usable excursion. The Fountek OTOH is the perfect example of why mathematical xmax is meaningless compared to referencing it at some distortion, currently the 10% HD or IMD in the IEC standard. The Fountek is rated at 1.5mm yet compare it to the HiVi B3S with its claimed 3mm of linear xmax. The Fountek is in a whole 'nother galaxy compared to the HiVi. Look here: http://zaphaudio.com/smalltest/

The No Quarter's are using birch ply all around but with the baffle a layer of 3/4" birch ply and 3/4" MDF. They have a very high resonant frequency, like tapping on metal almost. Sounds scary but these frequencies are much easier to damp than the <300hz resonances of MDF, which are basically impossible to damp. We'll see how it pans out, this is the first time I haven't used MDF.


Mayhem Beyma doesn't list that driver anymore, wonder if it's discontinued?
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post #8 of 603 Old 08-03-2009, 06:52 AM
 
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What will you do for a center channel for those that do not have an AT screen?

Added:
I am referring to the horn loaded speaker. I like your design very much. What is the depth of the box?
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post #9 of 603 Old 08-03-2009, 07:00 AM
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Quote:


The No Quarter's are using birch ply all around but with the baffle a layer of 3/4" birch ply and 3/4" MDF. They have a very high resonant frequency, like tapping on metal almost. Sounds scary but these frequencies are much easier to damp than the <300hz resonances of MDF, which are basically impossible to damp. We'll see how it pans out, this is the first time I haven't used MDF.

Great builds !!! The Surrounds are awesome....nice find wrt the fountek 3"!

Was there a link somewhere that lists the differences between birch ply and MDF? I know I read a couple but I havent found anything in searches this morning. Im using MDF in my build (so far) maybe I should switch?

I love the look of the bubinga, I used it on my VR-3s with a mapple curl baffle and they look better then any speaker finish I have purchased. Do you have pics on your bubinga application? its the non-paper backed corrected?

NOTE: looking at that picture and knowing Im doing the same build has me thinking we should have went with 15" drivers to match the size of tha waveguide

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post #10 of 603 Old 08-03-2009, 08:57 AM
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Regarding your 2way kappalite/CD, at that price, I may have to build a pair and see how it sounds. I've never been a fan of the horn sound, so if I don't like it, I can always resell it on here.

Keep up the hard work!

Quote:
Originally Posted by penngray View Post

NOTE: looking at that picture and knowing Im doing the same build has me thinking we should have went with 15" drivers to match the size of tha waveguide

Penn, do you have a build going in your waveguide thread?

YID DIY
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post #11 of 603 Old 08-03-2009, 10:26 AM
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Quote:
Originally Posted by penngray View Post

NOTE: looking at that picture and knowing Im doing the same build has me thinking we should have went with 15" drivers to match the size of tha waveguide

Yeah, I have these horns already, but after seeing them mounted they look a lot bigger. I think I'll be happy I went with a 15. Hopefully John will ship soon.

Also, great job Brandon. Thanks for all the hard work!
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post #12 of 603 Old 08-03-2009, 11:40 AM
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Yeah I think I'll be happy I went with a 15.

Do you have a thread anywhere discussing your project?
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post #13 of 603 Old 08-03-2009, 11:44 AM
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Quote:
Originally Posted by Monger View Post

Yeah, I have these horns already, but after seeing them mounted they look a lot bigger. I think I'll be happy I went with a 15. Hopefully John will ship soon.

Also, great job Brandon. Thanks for all the hard work!

That is what I said when I started the baffle last night....arrrg!! Those little things bug me (its a flaw I have, I like symmetry )

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post #14 of 603 Old 08-03-2009, 11:47 AM
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Quote:
Originally Posted by Looneybomber View Post

Regarding your 2way kappalite/CD, at that price, I may have to build a pair and see how it sounds. I've never been a fan of the horn sound, so if I don't like it, I can always resell it on here.

Keep up the hard work!



Penn, do you have a build going in your waveguide thread?

Yes, recent discussion in the thread has my WinISD plots and prototype box build I did on saturday and debates about Porting front or back matters wrt crossover designs.

I have a cool 22.5 router bit order for angled box builds and I ordered a 1.5" round over..Im travelling all week so nothing new will happen until next week Im hoping Brandon has some more measurements posted when I get back.

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post #15 of 603 Old 08-03-2009, 12:13 PM
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Originally Posted by BIGmouthinDC View Post

Do you have a thread anywhere discussing your project?

Not yet. Things are moving along slowwwly.

Basically I'm doing the same thing as these guys but with a td15m which I've been waiting since May for. I haven't decided on a cd yet either as I'm waiting to see Brandon's results. He has a good selection of cds he'll be testing.
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post #16 of 603 Old 08-03-2009, 12:24 PM
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Quote:
Originally Posted by Monger View Post

Not yet. Things are moving along slowwwly.

Basically I'm doing the same thing as these guys but with a td15m which I've been waiting since May for. I haven't decided on a cd yet either as I'm waiting to see Brandon's results. He has a good selection of cds he'll be testing.

You still don't have the TD15M.....thinking back I should have ordered it instead of the 12M.

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post #17 of 603 Old 08-03-2009, 12:39 PM
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Once Brandon paints the baffle textured black, I think the symmetry will look just right. The horn is about 11" where it starts the roundover and that's what you'll see when the color and texture of the baffle matches the horn. And now that I think about it, what you'll probably notice most will be the foam plug and it's smaller yet.

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post #18 of 603 Old 08-03-2009, 08:07 PM - Thread Starter
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Ya know the horn only looks outsized in those pictures, looks normal in person.

Repainted the BBV2 today in the shade and it was cooler with cloud cover. Much better. Good learning experience. 90F is too hot and 50F is too cold to get the proper fine grained finish it's capable of.
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post #19 of 603 Old 08-03-2009, 09:26 PM
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Quote:
Originally Posted by Monger View Post

Yeah, I have these horns already, but after seeing them mounted they look a lot bigger. I think I'll be happy I went with a 15. Hopefully John will ship soon.

Also, great job Brandon. Thanks for all the hard work!

I'm doing this build with TD15Ms and BMS4550 Hopefully the waveguide will work well with the 15" driver.

Still waiting on all my components too - though I haven't been waiting as long as you.
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post #20 of 603 Old 08-03-2009, 09:29 PM
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Brandon, I recall you calling it a PA speaker at one point - are you planning grilles?
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post #21 of 603 Old 08-03-2009, 10:50 PM
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Originally Posted by augerpro View Post


the crowd goes wild!

nice work man.

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post #22 of 603 Old 08-03-2009, 11:34 PM - Thread Starter
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Quote:
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Brandon, I recall you calling it a PA speaker at one point - are you planning grilles?

Nope. If some one were to build these for actual PA where they need to be protected they would have to come up with grills on their own.

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the crowd goes wild!

nice work man.

Thanks man
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post #23 of 603 Old 08-04-2009, 12:21 AM
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i can't wait to see how your design measures, particularly off-axis.

some sort of simple cover for the 12" driver is needed; maybe someone can design a slick-arse curved metal grill in order to put the final finishing design touch on these.

your design is reminiscent of a jbl "project" speaker. while surely not quite at that level in performance, these definitely don't have a budget look to the trained eye.

at least as far as the design goes, you have a real winner there. again, nice work.

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post #24 of 603 Old 08-04-2009, 06:53 AM
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Quote:
Originally Posted by findbuddha View Post

I'm doing this build with TD15Ms and BMS4550 Hopefully the waveguide will work well with the 15" driver.

Still waiting on all my components too - though I haven't been waiting as long as you.

Waveguides/CDs are at the house but Im on a business trip (1000 miles away).

I will ship at the end of the week!

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post #25 of 603 Old 08-04-2009, 07:34 AM
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Quote:
Originally Posted by LTD02 View Post

some sort of simple cover for the 12" driver is needed; maybe someone can design a slick-arse curved metal grill in order to put the final finishing design touch on these.

There's a nice curved one in this thread: http://www.audioheritage.org/vbullet...ad.php?t=18577 Looks like it's just screwed on over the drivers.

PE has some reasonable looking ones, but I'm not sure the best way to attach them - I'm hoping to avoid lips on the baffle edges: http://www.parts-express.com/pe/show...number=262-884

Quote:
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Waveguides/CDs are at the house but Im on a business trip (1000 miles away).

I will ship at the end of the week!

Yay
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post #26 of 603 Old 08-04-2009, 11:35 AM
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Quote:
Originally Posted by findbuddha View Post

I'm doing this build with TD15Ms and BMS4550 Hopefully the waveguide will work well with the 15" driver.

It should be fine. I ran some vertical polar map sims in LspCAD using a text file to simulate the horn directivity and piston diameter to simulate the woofer directivity. All are crossed LR4 at 1300 with the drivers crowded together. There wasn't as much difference in the size of the vertical lobe as I expected going from 10" to 12" to 15". All did fine in the horizontal as well.

Vertical polar map with a 10" woofer:



12" woofer:



15" woofer:


LL
LL
LL

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post #27 of 603 Old 08-04-2009, 12:03 PM
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Dennis for us newbies what are we looking at?
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post #28 of 603 Old 08-04-2009, 12:17 PM
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As you move up and down the pic from the center, you are moving off axis vertically. The degrees scale is on the left. SPL is represented by the color and it's legend is on the left as well.

Those blue dots in the middle are nulls caused by center-to-center spacing and the crossover frequency so you obviously don't want to be sitting in one of those. I picked where the map turns yellow (-8dB) as a convenient place to draw a line and get an idea of the usable vertical window. The window is wider with the smaller drivers but still not that bad with the 15".

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post #29 of 603 Old 08-04-2009, 12:22 PM
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Quote:
Originally Posted by catapult View Post

As you move up and down the pic from the center, you are moving off axis vertically. The degrees scale is on the left. SPL is represented by the color and it's legend is on the left as well.

Those blue dots in the middle are nulls caused by center-to-center spacing and the crossover frequency so you obviously don't want to be sitting in one of those. I picked where the map turns yellow (-8dB) as a convenient place to draw a line and get an idea of the usable vertical window. The window is wider with the smaller drivers but still not that bad with the 15".

So its safe to say that +/- 15 degrees is our window? Seems easy enough in most home environments, no?

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post #30 of 603 Old 08-04-2009, 12:44 PM
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Maybe +/-10 to not notice any particular difference with the 15". More with the smaller ones. That should be enough to cover having the sound not change when you stand up and walk around.

Of course, in the sim, the lobe is aimed straight ahead and that might or might not happen with a real crossover. But you can change where you put the speakers vertically and how you tilt them so you're still in the sweet spot of the lobe either sitting or standing. Just play a tone at the XO frequency and move your mic or SPL meter up and down to locate the nulls. Brandon will take care of all that in his designs but you guys going home brewed with different drivers will be on your own.

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