The BaSSlines (was High Sensitivity Design)

[dlneubec]

More Photos:

[dlneubec]

And three more (the slot port remains removable). Next up is to glue it all together and add the cross-braces and then work on the removable woofer baffle:

[Paul Ebert]

So, the dadoed slats are for reducing panel resonance?

[dlneubec]

Yes, that's the concept. Reduce panel resonance, while using up less volume for the bracing as compared to standard window bracing. I actually compared the volume of my original window bracing plan to the ribbed construction plan and the ribbed had about 17% less volume for bracing.

There was a thread on that over at the PE forume here:
Ribbed box construction

[dlneubec]

Here are some more construction pics. FYI, the baffles are test baffles. The finished ones will be laminated hardwood and Lexan as planned. The box has been glued up (except the top). The slot port will remain removable for two reasons. First, so it can be adjusted if need be, based on testing and listening impressions. Also, it will either be painted (the box will be veneered with Bubinga) or it may be replaced with a hardwood slot port. The woofer baffle will be removable. Here you can see the cross bracing implemented, including a "filler brace". This brace will be glued to front of the cross brace and have speaker gasket material on its face. It will physically connect to the back of the woofer. This will essentially connect the woofer to all four sides, to distribute vibrations and reduce motor movement. I have to add the small dowel, top to bottom, through the port, add front face cross braces that will be used for mounting threaded inserts for the baffle removal and pack the space between the ribs with insulation.

When the top and baffle are clamped on, the box does indeed sound quite dead, from a knuckle rap perspective. I have no other way to test it. Of course it will be even better when the top is glued on, the filler brace fully implemented and the final version of the port glued in.

You can see the woofer mounted from the back, 1/2" inset, with 1/2" roundover. I want to cut a steeper chamfer on the top of the woofer baffle, probably 30º or less.

[ThomasW]

Looking good Dan.... :T :B

[Hdale85]

Agreed!

[Paul Ebert]

I really like the dadoed slat idea. I think I'll do the same for my Trilliums. It appears that you ended up going with oak, correct? I'll use oak as well, since it isn't undersized like plywood. I don't have a dado blade, so I'll have to use my router and router table.

Thanks for the idea!

[dlneubec]

Yes, they are red oak. First I ripped several pieces and decided it would be simpler to buy 1/4" stock, which my local Menards carries. I bought 1/4"x8" stock and ripped them to 1-1/2" wide slats, then set in 1/4"wide by 1/4" deep dadoes.

I described how I located the slats in the posts below, though I ended up with the 1/4" red oak in the end, all the same depth.

http://techtalk.parts-express.com/showpost.php?p=1519339&postcount=14

http://techtalk.parts-express.com/showpost.php?p=1519648&postcount=42

One other interesting thing is that the ribs give a lot of extra surface to glue cross-bracing to, instead of just the end of he brace, if you get what I mean. Only glue was used, no screws.

[dlneubec]

I’ve got a prototype of my BaSSlines together, for testing purposes, though I don’t yet have my midrange drivers yet, since they are on backorder until October 10th. Instead I popped in some used Audax Pro mids into the open baffle.

I started with Jeff’s original crossover for his Salk speaker and just made some adjustments by ear and also knowing that the tweeter would have a boost at the low end due to the 1/2" deep waveguide mount. Based on my raw listening impressions, I'll say is I think these could be very, very good. The TD12H is one clean woofer. I think the Peerless HDS tweeter in the ½” waveguide is going to work out very well also, based on this test.

Here are a couple of photos of what I’m listening to as I build the second box and wait for the mids to get into stock. I should be starting on some measurements soon on the TD12H and the HDS. I have the Lexan for the open baffle section, but see no reason to mess with it until the design is nearly finalized.

[augerpro]

Looks solid Dan. What mid did you decide to go with again?

[Saurav]

If that's the PR170M0 and you have some free time while waiting for the final mids (B&C? PHL?) and you can take some measurements of it, that would be awesome

[dlneubec]

Brandon, I have two B&C md38's on backorder at PE.

Saurav, when I get the other box done, probably some time next week, I'll start on measurements and will include the temporary mid (yes those are the PR170MO). I want to find out what, if any, negative impact, shows up in the measurements due to the recessed mounting. I'm going to have to make a test baffle for a standard flush mount for comparison purposes. I do like the way the rear mount looks. The aesthetics are very simple and clean. It reduces the impact of the driver sizes and makes no grills more acceptable. I think it has a little higher WAF as well :W .

[Saurav]

I want to find out what, if any, negative impact, shows up in the measurements due to the recessed mounting. I'm going to have to make a test baffle for a standard flush mount for comparison purposes.

That will be an interesting test. I guess it might also depend on the crossover frequency to the tweeter, i.e. maybe you could choose a combination of XO frequency and roundover/chamfer sizes to push any diffraction effects into the stopband?

What are the woofer-mid and mid-tweeter distances, and the XO points in Jeff's XO?

[dlneubec]

It will be unlikely that I will use this mount if any diffraction artifacts show up in the passband of the drivers. Jeff recently completed an LS3/5a clone (a two way) and mounted his woofer this way. He did not think it would be a problem for me in this design, but testing will certainly confirm that.

I think Jeff's crossover points were about 450hz/2500hz or so, IIRC. My woofer to mid distance is further than his was at about 20" and my mid to tweeter is about 6.5", about the same as his was. My ear height is about 1.5" below the tweeter axis. Bear in mind that my woofer is on an angled baffle, tilting the axis up 8º, which brings it to an intersection with the mid at about 12', which is my intended listening distance. The Salk speaker has a single flat baffle.

[dlneubec]

Well, I finished the boxes and Im ready to start some measurments, but I don't have the mids yet. They are on backorder until at least 9/30. In the meantime, I’m starting on the laminated baffles for the BaSSlines. I'm going to keep it simple and use easily available hardwood for the laminated sections, most likely walnut and maple. I decided to flip the color scheme and go with a predominantly dark baffle with light accents and light box (see below). Which do you like?

[Hdale85]

3 for sure for me.

[Saurav]

3. Definitely not 2 On 3, I'd even make the 2 outermost laminates on the tweeter dark, so you have a constant width to the narrow stripe. This may look better if you made the baffle 'rings' wider so they meet between the drivers, either at the circle edge/tangent, or if you go even bigger, then as partial circular arcs. Though I'm not sure if you have enough baffle left to make the lower circle bigger, and just making the upper one bigger may look weird. But if they met with a thicker 'joint', to where the dark brown from the lower circle touched the upper one, that might tie them together too.

But I'm not sure that idea will work, so yeah, 3.

[augerpro]

I like the dark with light accents better too.

[Hank]

3. Not 2 for sure.
Have fun!

[ttan98]

Brandon, I have two B&C md38's on backorder at PE.

:W .

I think US speakers have them in stock for about similar price, $92 each.

[dlneubec]

Yeah, but I have a $500 credit at PE, so I want to get them there. :W

[chrisn]

I really like the test cabs, as well as having the drivers mounted from behind, kudos

I vote for option number two

That TD12 looks all business.

[dlneubec]

I appreciate the feedback guys. It looks like # 3 is the winner. My wife likes it best also. I just have to figure out what hardwood to use. It is so expensive now and I figure I need about 35' of light colored hardwood and 70' of dark colored hardwood for two speakers!

I was looking last night at Maple and Walnut as a combo at Menards. A 6' 1"x6" walnut board was $43.50! Maple was nt too bad at about $16.00 for that size. Other possibilities for the dark wood is Cherry and Mahogany. I've never used Mahogany, but it is low priced at under $12 for that size, bu cherry is just about the same price as walnut.

The dilemma is that I have to use the natural wood colors due to the way these are laminated and will be sanded flat together as one panel. I'm trying to decide between Walut/maple and Mahogany/maple. This is a more realistic mockup of those combinations.

[Paul Ebert]

I wonder if you'd find jatoba (Brazilian cherry) to be cheaper (if you could find it locally) than walnut. Any of these will be easy to work with. I've always wanted to build something from walnut. It's supposed to work very cleanly.

Jatoba can be very beautiful, not that walnut or mahogany are ugly...

Would you consider simply staining the maple to make the contrasting wood? One benefit to that would be that the expansion rate would be the same (you are using solid wood, right?).

[dlneubec]

I'm not sure how I would do the staining. The idea is to glue these panels up as laminated vertical pieces, which will have to be sanded flat. I don't have much confidense that I could simply mask off some of the maple and not have seepage of stain under the tape or even through the wood to the contrasting pieces. I could try to seal the contrasting pieces first, which could help, but I'm still not convinced that would work.

Besides, I'm not a big fan of stain and really prefer to use natural wood colors. I think I have a lead on a good hardwood supplier that will present a lot of options, including natives like ash, basswood, cherry, birch, maple, hickory, polar, read and white oak, sycamore and walnut and exotics like Jatoba, Wenge, Makore, Bubinga, Laewood, Mahogany, Padouk, Teak, Zebrawood, etc., though they are about a 3 hour drive away. :E

I'm probably going to mock up some options using Maple and Sycamore as the light wood and various exotic hardwoods, maybe Makore, Bubinga and Padouk, for example. I may go for a dark bass bin box as well, but with a contrasting strip between the baffle and the box body.

[---k---]

Dan,

I do like Jatoba. I used some to make a picture frame. I think it would contrast maple very nicely. I'm not a fan of walnut.

Is the supplier that you're talking about Owlhardwood.com ? The Lombard store is about 20 minutes from my place and probably about 3 hours for you. I've purchased my birch ply from them and some other hard wood. I can definitely recommend them. Good people and good stock. You should just swing by them on your way to Iowa.

[EdL]

lumber sources

Dan, I didn't realize Miller was 3 hours away. There's got to be sources in S. Indiana/Louisville or Indy. Your interest in "red" tones would lead me to jatoba or bubinga.
Don't get the first board you find. Every hardwood has a wide range of grain/color figure. It pays to be selective. Maybe curly maple? :T

[dlneubec]

Dan,

I do like Jatoba. I used some to make a picture frame. I think it would contrast maple very nicely. I'm not a fan of walnut.

Is the supplier that you're talking about Owlhardwood.com ? The Lombard store is about 20 minutes from my place and probably about 3 hours for you. I've purchased my birch ply from them and some other hard wood. I can definitely recommend them. Good people and good stock. You should just swing by them on your way to Iowa.

No, it's Frank Miller Lumber Co., which Ed suggested to me. I have not seen Jatoba yet, but bubinga and Padouk look very nice with maple or sycamore. :B

[dlneubec]

Dan, I didn't realize Miller was 3 hours away. There's got to be sources in S. Indiana/Louisville or Indy. Your interest in "red" tones would lead me to jatoba or bubinga.
Don't get the first board you find. Every hardwood has a wide range of grain/color figure. It pays to be selective. Maybe curly maple? :T

Yes, I need to do some searches for hardwood lumber suppliers to see what comes up! Curly Maple would be nice also :T

[ClintonH]

I'll put a vote in for Jatoba as well if you can make it work, great looking wood. I have 2 pallets of it siting in my house accumulating for the last 3 weeks, I'll be putting it all in shortly. Hope that's one of the last house renos.

Clinton

[John_E_Janowitz]

Dan,

The old meadowlark audio site had lots of nice wood combinations on speakers. Might want to look at a couple of the galleries to see how some combinations work:

http://web.archive.org/web/20050207215401/www.meadowlarkaudio.com/bh2Swimsuit.htm

http://web.archive.org/web/20050209040526/www.meadowlarkaudio.com/bh2Swimsuit2.htm

If you're looking for some really unique stuff, check out these people:

http://www.righteouswoods.net/woodmenu.html

I'm thinking something like a curly/waterfall bubinga would be very attractive.

Image not available

Image not available

Padauk is extremely red and good for accents as well. These people on ebay have lots of good pictures of their stuff. Although none of it is very cheap.

John

[dlneubec]

Hi guys,

I'm starting on some measurements. I'll post some later. Here is what I'm currently thinking on the finish. Padouk and Maple or Sycamore. This one is with maple.

[Hdale85]

I really really like those colors. Very deep and rich feeling.

[augerpro]

Dan if it's not too much trouble do you think you could whip up the TM baffle but use a 1/2" chamfer for the tweeter instead of a roundover? And maybe even another chamfer using something with a lower (20-30 degree) slope? Just curious how that would compare with the roundover. I have a gut feeling you might get more even loading at lower frequencies doing this. Also when pushed on using waveguides for dome tweeters Geddes said the optimum shape would be conical versus a curved (OS) wall.

[---k---]

Dan,
The sketchup models are pretty, but I think they'll all go out the window when you get to the lumber yard. You'll know which woods are the right ones when you see them.

I'm also very interested in what the roundover does to the tweeter measurement. Looking forward to seeing those.

[dlneubec]

Dan if it's not too much trouble do you think you could whip up the TM baffle but use a 1/2" chamfer for the tweeter instead of a roundover? And maybe even another chamfer using something with a lower (20-30 degree) slope? Just curious how that would compare with the roundover. I have a gut feeling you might get more even loading at lower frequencies doing this. Also when pushed on using waveguides for dome tweeters Geddes said the optimum shape would be conical versus a curved (OS) wall.

Interestingly enough, I had need to test both a standard flush mount and the 1/2" deep waveguide mount an also wanted to see what would happen if I created a 3/4"+ waveguide by mounting the tweeter to the back of 3/4" stock, not removing the faceplate of the tweeter. The latter two I accomplished by making one baffle with a 4-1/4" through hole and a 1/2" rebate and several wood inserts that fit in that hole and rebate. I then installed the tweeter in those inserts. Sort of the same idea that Zaph uses for his infinite baffle testing.

So, I have now tested flush mount, 1/2" deep waveguide and 3/4" deep waveguide. The 3/4" deep wavguide was done as follows, since I don't have a 3/4" roundover bit at the moment. First I rounded it over with a 1/2" bit. I actually tested it this way outside. Then I used a 1/2" chamfer bit to open up the hole. Then I sanded the sharper edges by hand to round them over. This is what I tested with indside. I'd still like to test that with the tweeter face plate removed, as it is in the 1/2" waveguide. I would guess having the faceplate on adds at least 1/8" to the depth of the 3/4" waveguide, which I filled by using speaker gasket tape.

Here are some measurements of the three. The flush mount and first 3/4" waveguide measurements were done outside, at 103" and only 0,22.5 and 45 degrees. The 1/2" waveguide and second 3/4" waveguide were done inside, at 1 meter and a 4ms window, with the tweeter up about 6' off the floor, at 0, 15, 30, and 45 degrees. The relative spl levels between inside and outside measurements are meaningless.

The 1/2" waeguide provides a subtle boost that flattens out the rising response of the tweeter from 4khz to 20khz on axis. For example, from 2khz to 17khz there is a 5db rise in the flush mount FR. With the 1/2" waveguide, that is reduced to about 1/2" that.

The 3/4" waveguide provides a much larger boost, centered around 2.7khz. The modified 3/4" waveguide is not too much different, so opening it up with the 1/2" chamfer did not seem to have too much effect. I will probably test a 1/2" wavguide with the rounded chamfer that you suggest. It will have to have 45º sides, since that is all I have in chamfer bits.

Peerless HDS Tweeter tests:

Flush Mount: outside at 103", 0, 22.5 and 45 degrees horizontal off axis:



1/2" deep waveguide: inside at 103", 0, 15, 30 and 45 degrees horizontal off axis:



3/4" waveguide: outside at 103", 0, 22.5 and 45 degrees horizontal off axis:



Modified 3/4" waveguide: inside at 1m, 0, 15, 30 and 45 degrees horizontal off axis:

[dlneubec]

Here are some Lambda TD12H and Audax Pro170 mid measurements. The Audax is just temporarily being used while I'm waiting for the B&C 6md38's to come in. Both of these were tested on axis, mounted from the rear with a 1/2" roundover. The TD12H was measured outside and includes a far field and almost nearfield (about 10") merged.

TD12H:



Audax mid:

[Saurav]

Is there any smoothing applied to these graphs?

That Lambda woofer is amazing. You could almost get away with not using a midrange

[dlneubec]

I believe I had it set to 1/6th octave smoothing, but it was not much different with less smoothing. The main reason this looks smoother is the short gated window used during measurements. When using a smaller gated window, like the 4ms I used in my far field measurements, you get a much smoother FR because you don't have boundary reflections polluting the measurements.

Here is a preliminary passive xover simulation with crossover points around 450hz and 2500hz.

[augerpro]

Those Lambda's are nice. Interesting.

The waveguide measurements seem a bit inconclusive to me. I'd still like to see 1/2" roundover versus 45 degree chamfer at the same angles, gate, etc. The same comparison in 3/4" would interesting too. If understand correctly the 3/4" test is really just a 1/2" chamfer on a 3/4" baffle? So there is a 1/4" "tube" from the chamfer to the tweeter faceplate? Not sure if I care for that. Clearly there is a benefit to the 3/4", but using a true 3/4" chamfer bit with the mouth of the cone coming to an intersection right at the base of the tweeter dome would be more optimal I would think? Time to visit HD Dan :B

[dlneubec]

Yea, I should pick up a 3/4" bit. I've been going to do that anyway for some time. If I do, I can use it on the 3/4" mount I have now. I'd like to try a 3/4" roundover bit on a 1/2" and maybe a 5/8" deep wavguides as well.

The difference using the 1/2" waveguide is less in those graphs because the graph for the flush mount was taken outside at 103inches and the 1/2" I showed was taken inside at 39.375". I did take one, however, for the 1/2" outside. Here is the on axis for the two overlayed when taken under the same conditions, spl levels, etc., outside at 103". Sorry for the confusion. This shows a little more difference between the two than what is apparent in the graphs above. It looks much more effective here, don't you think? At any rate, it made dealing with the rising top end of the HDS a moot point and what it shown is a simple 3 part xover in the simulation above.

[Dennis H]

Hey Dan, I have a favor to ask. Your pics are way to big for those of us still using old CRT monitors. I end up having to scroll your posts to read them. It's even worse over at the PE board where a big pic makes you scroll the whole thread. Some boards restrict the width to 800 pixels or less and I'd say that's a pretty good guideline.

[---k---]

Dennis,
Glad to see I'm not alone At least here, it doesn't screw up every post like it does on other forums.

[dlneubec]

Hey Dan, I have a favor to ask. Your pics are way to big for those of us still using old CRT monitors. I end up having to scroll your posts to read them. It's even worse over at the PE board where a big pic makes you scroll the whole thread. Some boards restrict the width to 800 pixels or less and I'd say that's a pretty good guideline.

Hi guys,

Where possible I have been resizing the graphics to about 900 x 900 or less. When it comes to the SoundEasy graphs, I use a capture program to get specific graphs. It does not have a way to set the resolution and my attempts to resize them in another program has so far left them unreadable. I'll take another look at it to see what I can come up with. I may be that I'm using a 22" flat panel set to 1920x1200 and it picks up the capture based on that resolution. I have been trying, but I'll try harder! :T