Looking to build a 3.5 way speaker system

[cjd]

We begin to get into smaller concerns where your desired woofer and your desired cabinet direction can all work together.

Center to center spacing needs some attention, relative to frequency wavelength at crossover points. You also have the woofer quite close to the floor where it'll have more floor bounce issue (but also more boundary gain) so that should be considered. Woofer to lower mid is probably just workable assuming something in the 200Hz range. Lower mid to upper mid, I'm not so sure will work, though having this (upper) be more of a "filler" driver than a full on crossover (where there is also significant overlap between the lower mid and the tweeter, and this driver is probably -3dB or -6dB from nominal) you begin to have something workable. Even something like a dome mid could do well here.

We're getting to where we need to consider what other drivers to put into this package. I think that once we consider baffle step, we'll be looking at 90-93dB (depends how floor boundary gain goes) nominal - let's take a look over our tweeter options to find something that's in that ballpark and see where that leaves us on crossover frequency options which will help with the choice of the remaining two drivers.

[---k---]

They look menacing! I like it. Good luck.

[Curt C]

I have to say I am really enjoying this.

Yeah, that’s the way we are… Just ask us our opinions, and away we go! :dothewave:

The cabs look great :T A very nice looking design. As Chris has indicated, we need to now consider the other drivers and their passbands to make sure the driver spacing is workable, sensitivites and excursion limits are appropriate, etc.

Chris, I think you meant to say the JBL woofer being lower to the ground will result in less floor bounce dip, rather than more, -and likely out of its ultimate passband anyway.

The upper woofer will suffer floor bounce, of course, so the crossover frequency should be chosen to be at it’s floor bounce frequency at the intended listening distance.

Soooo…. dmm: Give us a driver budget, and we’ll armchair quarterback a great selection of drivers for you. –Not that any of us will ever agree on the best selections…. :bash:

C

[ThomasW]

The design looks nice. Problem is you're going to have a HUGE, VERY HEAVY tower system, and still need a subwoofer if you want to hear the really low stuff on DVD's

[cjd]

Curt, you're right. I was thinking reflections and bounce and everything else...

Do you think this is likely to land closer to 91dB or to 93+? Obviously that rather impacts what tweeters are potentials.

[cjd]

Vifa DQ25SC16-04 if we need more sensitivity and are more budget conscious
Scan 6600 if we've got some budget to play with and 92dB is plenty.

Ribbons are also an option here.

So many choices, and yet... where do we land on sensitivity will be rather important.

[dmm]

If you check back to earlier posts, I listed what I thought was a good bang for buck / performance grouping of drivers, tested and and accepted on the "Zaph" site. I trust the judgements already made, as opposed to going to catalogs and picking what looks good. For what it's worth, I always wanted to do this project because music is an integral part of my life. I thought the JBL's, although old, would offer sound lower than I have experienced in a long time. In the "Belle Klipsch's", which is a folded horn, they are very effecient. I don't have any measuring equipment and would prefer not to have to invest since this will probably be a one time event. I live in Upper Montclair, NJ and if there is someone nearby who is willing to work with me I will gladly share credit. I view this as a work of art, one that will have lasting value. I have obviously attracted some interest and would like to take the project to resolution.

[cjd]

If you check back to earlier posts, I listed what I thought was a good bang for buck / performance grouping of drivers, tested and and accepted on the "Zaph" site.

Yes, and none of them will work unless you actively cross the JBL's, because you'll have a net sensitivity around 82dB (limited by the single RS180 you proposed) and at least 8dB more at the same input level on that JBL. Though in fact ALL the drivers you listed (perhaps not the tweeters if this does in fact land around 90dB) will be limiting factors.

Zaph has also given his seal of approval to both tweeters I mentioned, but I will admit I'd forgotten about this - as such, this suggests the Vifa, of the two.

The Dayton RS drivers are (or have been) value leaders, but the sonic characteristics compared to the JBL are, I think, going to be audible. That said - were I going down the road (but not quite) you've sort-of laid out, I'd go RS225-4 or RS180-4, RS100-4, and the Peerless HDS tweeter (though I'd choose that Vifa to allow the center-center distances to be snugged up as much as possible). Though I think you could do without the RS100-4 in this mix, crossing the RS225 around 1200Hz (RS180 around 1500Hz) and the tweeter around 2000Hz and I think this guy could fill that gap without TOO much C2C problem and despite the big sensitivity difference. Guessing a bit here.

On the flip side, still opting for that Vifa tweeter, I might consider instead the B&C 6MD38 - though that can likely cross straight over to the JBL on the bottom, an 8" might be a little better - say, the B&C 8PE21. Neither should need a 4th driver in the mix, but if you want that, the above topology where it's not really full output but instead providing a little fill between tweeter and mid-woofer, one of the T-B bamboo (4" perhaps) could do superbly (though not limited to those).

That's my line of thinking on this, anyhow.

C

[BobEllis]

...So many choices, and yet... where do we land on sensitivity will be rather important.

Not if you go with all active XOs. :W

[cjd]

Not if you go with all active XOs. :W

Yes, of course - I'm making an assumption that we're looking at passive. Powering 4 way actives isn't entirely cheap on the amplification end of things. Though I believe significantly mismatched drivers when it comes to sensitivity ultimately shows up, as they often don't "scale" well (i.e. matched at 70dB listening level may be mismatched at 90dB)

[bluewizard]

Just a couple of tangental questions.

In the earlier drawings, we see the low bass speakers view from the side and they have a somewhat trapezoidal appearance. I know we are past that now, but is there any advantage to that shape in a side firing woofer? I would say not, but then I'm far from an expert.

What I am going to say next came up in another discussion, and I think it is relevant here. Though how relevant remains to be seen. Given the complexity of a 4-way design, and given the expense of a full active crossover systems and separate amps, wouldn't it be better to either place a Sub Amp on the lower section and build the upper section as a standard passive 3-way?

Alternately, if sub crossover frequencies aren't correct, couldn't you use a separate amp and active crossover on the lower section, and keep the upper section as a passive 3-way?

I'm always looking for the cheapest way to accomplish something, so take that into consideration.

Still, it does look like one mean and powerful speaker system.

I do agree with some of the comments that CJD made. Given the speakers you have, I don't think treating the bottom section as a standard sub is the way to go. But, as CJD suggests, crossing over higher may make better use of the speaker.

Still, I'm just making wild conceptual guesses.

If someone could comment on my first question about the shape of the cabinets, I would appreciate it. Again, acknowledging that we are way past that design now.

Steve/bluewizard

[cjd]

A trapezoid shape as "seen" by a driver can help with edge diffraction. And internally, a non rectangle shape for the box can help reduce problems with standing waves.

[bluewizard]

A trapezoid shape as "seen" by a driver can help with edge diffraction. And internally, a non rectangle shape for the box can help reduce problems with standing waves.

Thanks, but side-to-side, that is with the woofer mounted sideways, the woofer is on a flat surface that is parallel to the other side, or relative to the woofer, the front is parallel to the back. Does that shape really help that much.

Again, I realize that we are way past this in the design, and I think what started out as an idea to use to spare JBL speakers is turning into something really impressive.

On the shape issue, this is just a side note for my personal benefit. As I said, we are past this now.

And, now a slight apology. I just realize that this was the very thread where I had made the Sub-Amp suggestion before. Sorry, I've been in and out of so many thread on so many forums, I can't keep track of what I said where.

I still think it is a good approach, but at the same time acknowledge that I'm in way over my head here.

Steve/bluewizard

[dmm]

Just for info. SEAS 27TDF 6ohms, 2,500-25,000 hz Freq Range, 92 db at 2.83V.1m. Dayton RS125S-8 8 ohms, 70-4,000 hz Freq Range, 86.5 db 1w/1m, Dayton RS180S-8 8ohms, 40-2200 hz Frq Range, 87.6 db 1w/1m. I don't have similar data at hand for the JBL's. I see the problem with freq range withthe Dayton's. What if I keep the design and turn the project in to a 3-way with MTM top and the JBL bottom. If possible, can I take a successful MTM design, crossover and all, add the JBL bottom. This would reduce the cabinet height some. If possible, what will mate with the JBL bottom? If I put a couple of TB mids in there, would that make sense? In my "Zaph" listings, he designed his bargin aluminum MTM with a SEAS tweeter and a pair of Dayton DA175 woofers. Speaker Builder 201 had the Spike with a Morel MDT-33 tweeter and two Eton 4" mids. From Parts Express DIY I found the Matt Olsen Trap, Morel tweeter with Dayton 295-300 5 1/4" mids and Dayton 15" Series II woofer. The Millennium III with a Vifa tweeter, and two HiVi 5" mids. Or the VHT with a Vifa tweeter and two Dayton DA135-8 5 1/4" mids. Troel Gravensen has the HDS 164 with a Vifa tweeter and two Peerles HDS 164 mids. Also the Jim Holtz with a Fountek Neo ribbon tweeter, (did I write that?), and two TangBand W4-1337SA mids. Somewhere in all this may be a solution. But getting back to my original thought, Troels has a design called the DTQWT in which he uses a JA 8008 tweeter, TWO 34 mid, and on the bottom a Beyma 10LW30N woofer and a Pioneer A256C40-51F-Q woofer. Interestingly enough, he used the two woofers in the same crossover circuit. The other 3.5 way I saw was from Gatti called the Delta. Morel Supreme tweeter, Audio Tech CQuenze mid, Scanspeak 18W8531G00 midbass, and a Scanspeak 26W8861T00 woofer on the bottom. Sorry I ran on but the info might be helpful.

[cjd]

So, using either of the pro mids I mentioned would get you a very solid 3-way, just 3 drivers and net cost probably less when you consider fewer crossover parts.

If you want to go MTM up top, also possible - a couple RS150's would do nicely especially if you handle baffle step in the woofer, keep the sensitivity up.

It's not really cost effective to try to passively cross any existing design with a new woofer - if you're talking active still, absolutely. But with your design direction I still see it being a crap-shoot - better to go at it directly and measure then do crossover.

I forgot there's a plain Seas TDF Workable also.

Check the 4ohm versions of the RS family, sensitivity is up on them.

There are a TON of directions you can go here, I'm not so much trying to make a decision for you as to think out loud.

If you went with the 6.5" B&C mid (Zaph HAS reviewed this and liked it) you could also roll over to a nice ribbon tweeter up top and keep the box shape almost exactly as you have it since a ribbon with a rectangular face would match that upper box rather well.

C

[Curt C]

Possible driver options: (IMO, of course...)

Starting with these presumptions:

*The JBL specs are correct and we start with a 94 dB sensitive woofer.

*A 3 dB baffle step or less will be required, as these big guns are likely going to sit fairly close to the front wall. The less the baffle step, the more sensitive the rest of the drivers will need to be.

*The JBL’s will cross to the lower woofer somewhere around 300 – 400 Hz.

*At least some of the baffle step will be within the lower woofers passband.

This suggests that the minimum sensitivity for the lower woofer would be 90 to 91 dB @ 2.83v/m, and consequently limits our driver choices to a mere few. This also suggests tweeters with sensitivities of at least 90 dB should be acceptable.

After researching this, the top of my short list would be the same as Chris’s suggestion: The B&C 6MD38-8. This driver has quite a few advantages in this context. Not only will it cross well to the JBL’s, but its top end CSD and HT plots suggest a 2K crossover point would be acceptable. This would allow the majority of tweeters to be considered, and allows a 3 way system with little or no compromise, even compared to a 4 way system. This driver does not need a large box at all, and could easily be incorporated into the woofer cab, by moving the woofer ports to the rear.

The PLH 1120 would also be an excellent choice, but the pincushion frame is a PITA to recess on the baffle. That reason alone is enough for me to ignore it as a contender. Others may enjoy the challenge….

Another possibility would be the RS225-4, which manages the sensitivity requirement with 92 dB @ 2.83v/m. This will take a larger box than the B&C, but still fairly small. It has a couple of issues: It will run out of SPL before the B&C, -not from excursion, but from thermal limitations. Just how high it will go before the glue melts is difficult to say, but I suspect it will be fine at sane listening levels. The other issue would be its reduced usable passband, which eliminates a 3 way as a possibility.

As you’ve suggested dmm, an MTM will provide both the passband and sensitivity required, and certainly could be another avenue to try. Smaller diameter drivers can be used, whose wider upper end bandwidth would open the door to ribbons tweeters as well.

One caveat here:
If you determine to design a system with your own driver selections, etc., the services of someone who can measure the drivers in the enclosure and design a proper crossover for them will be imperative. To do less will result in a design that in all likelihood will not meet your expectations.

On the other hand, it would be much easier to modify an existing MTM design into a 3 way, although it still will require some expertise to optimize the ‘marriage’. I found the JBL’s in particular will require a somewhat atypical crossover topology to obtain an acceptable transfer function, and still attain an f3 in the upper 30’s.

I’m about 1300 miles west on I-80, so unfortunately the freight costs will probably eliminate me as a designer. -But it would be an enjoyable project to tackle…

C

[dmm]

I've been busy trying to find a compatible MTM to put on top. I'm suprised someone didn't mention the Modula MTM 1 that ran so long here. I tried to follow thru the whole thing but I wasn't able to find a good drawing of the cabinet plan. I would also like to know what the final decision was for the crossover. Any suggestion please. Just for information, I intend these speakers for just listening to music, not a theater environment like I see so often. My equipment is all Adcom, ( GFA555 amp, GFT555 tuner, GFP555 pre-amp, and a GCD575 cd player). In addition, I have a Yamaha K950 cassette deck, and a Thorens TD166 MII turntable with a high end Grado cartridge. My speakers are a rebuilt pair of EPI Quartro that when I rebuilt them, I added a 4" midrange to fill out the voiceing.I have over 4,000 albums going back to 1962 which I listen to off and on. Still hopeing to hear from someone who can help measure these when their done. Thanks to Curt, CJD, Bluewizard, and everyone giving me a hand. I will try not to end up with 21 pages or so though to get these done.

[dmm]

Before I go, how do I determine the Baffle Step on the JBL so I know how far off the floor to mount it? Also, if and when I find the right MTM match, can I change the shape of the cabinet to suit my taste, as long as I keep the same volume and speaker placement on the front baffle? Assuming that all else is equal, will changing the shape really throw the crossover out of wack? If the MTM I choose has an offsaet to the tweeter, it might add some visual excitement to the design. About the B & C 6MD38-8 speaker, it has no visual interest for me, may not be the right attitude, but the visual design is important.

[ThomasW]

Please format your posts into paragraphs so they're easier for old eyes to read.

Thanks....

[Curt C]

Before I go, how do I determine the Baffle Step on the JBL so I know how far off the floor to mount it? Also, if and when I find the right MTM match, can I change the shape of the cabinet to suit my taste, as long as I keep the same volume and speaker placement on the front baffle? Assuming that all else is equal, will changing the shape really throw the crossover out of wack? If the MTM I choose has an offsaet to the tweeter, it might add some visual excitement to the design. About the B & C 6MD38-8 speaker, it has no visual interest for me, may not be the right attitude, but the visual design is important.

Download The Edge program from Tolvan Data. You can model the changes to the baffle shape and see the BSC effects.

http://www.tolvan.com/

Where you mount the JBL's will have little effect on the baffle step, but will have some affect at higher frequencies, depending on where you cross to your MTM.

The diffraction effects of the MTM can be modeled as well, and will be affected by more than minor changes in baffle. Best to stick very close to the original MTM design you choose if you want to retain its intended voicing.

Just like life: In Speakerbuilding, Everything affects Everything Else.

C

[dmm]

Thanks for the tip, I downloaded both "Edge" and "Basta" for future use.

I just spent another day looking at the "Modula MTM" project and since it fits very closely with my original driver thoughts, I feel confident in using it.

Now comes the interesting part. If I use the Modula on top, what if I used a 10" or 12" Dayton woofer on the bottom? Make it a 3 way design, reducing the size a bit with a smaller bottom box. Might be worth entering in a Dayton DIY Comp.

On the other hand, I still have the JBL's and ? How hard would it be to cross them from the MTM's?

One last question about the MTM's. If I respect the front baffle layout, can I play with the shape of the box a little to give it some visual interest?

[cjd]

If you put two Dayton RS270's (10") under the Modula MTM and make it a single cabinet you have my bigger 3-way towers.

The JBL's would be crossed actively unless you want to rewrite the crossover - you can certainly do this at a higher frequency (~250Hz-ish for the Modula IMO) but I think a lot of us prefer passive (or just get stuck in that rut) - probably why the Modula didn't come up specifically (though I think "pick a Missions Accomplished design and actively cross the JBL's in a bass bin) came up.

Front layout and front baffle width are both important, and with as optimized a design as the Modula MTM I'd be hesitant to do a whole lot to change this shape - height is also to some degree but less so - it isn't generally considered an issue to take a design like this and make a tower out of it, for example.

C

[dmm]

In my attempt to continue to push the envelope, I noticed that both the Zaph Bargain Aluminum MTM, the Modula 8 MTM, the Dayton III MTM, and the Dr.K MTM projects all have the exact same cabinet size although different drivers and crossovers. I've also been looking at the top MTM of the Millennium III project. The question is, which one will work the best with the JBL's on the bottom?

Next question, providing that I can use one of them, can I split the single cabinet down to a top cabinet with a Mid above the tweeter, and stack that above the second mid, in it's own cabinet, all sitting above the JBL's? Assuming of course that each of the cabinets is of appropriate volume.

At lastly, I was looking for more info on the JBL's and found that Troels Gravensen did 2 different JBL projects. The JBL L100 Century project, and the JBL Decade Restoration project. He likes the JBL's he had, although they were smaller than my 15" woofers. Here is the question, he crosses the woofers at 800 hz. What if I used the same crossover as a basis for my woofers in a 3 way configuration?

[ThomasW]

In my attempt to continue to push the envelope, I noticed that both the Zaph Bargain Aluminum MTM, the Modula 8 MTM, the Dayton III MTM, and the Dr.K MTM projects all have the exact same cabinet size although different drivers and crossovers. I've also been looking at the top MTM of the Millennium III project. The question is, which one will work the best with the JBL's on the bottom?

The modula MTM is the most sophisticated design.

Next question, providing that I can use one of them, can I split the single cabinet down to a top cabinet with a Mid above the tweeter, and stack that above the second mid, in it's own cabinet, all sitting above the JBL's? Assuming of course that each of the cabinets is of appropriate volume.

Yes but only if you re-engineer the crossover because the spacing between the drivers is critical.

What if I used the same crossover as a basis for my woofers in a 3 way configuration?

Different driver = different crossover.

[dmm]

Thanks for the response ThomasW.

Although you say the Modula is the most sophisticated, will it integrate well? If so, I now have one question solved.

How hard is it to modify the crossover for the mid cabinets, since my design looks to have a mid cabinet with it's own driver in the middle.

[cjd]

It will integrate as well as any of the rest. The sound character differences and the sensitivity differences between the JBL' and ANY of the projects you've highlighted are similar.

"Modfiying" the crossover is as difficult as designing one from scratch, if not harder (when you build from the start, you have some sense of what this or that change will do to the net response before you make the change - when you're trying to modify an existing design, you don't even have that advantage)

C

[dmm]

I guess I should just go forward and do what I would like to, and see where it leads me. I will play with the design and list the speakers and post it as a definitive project so we can go to the next step. Thanks for all the support cjd.

[cjd]

Heck - you could build one of those designs as-is, see how it sounds. Get a Behringer and play with crossing in the JBL's, see what that does for you.

Any of the RS180 based designs will benefit from a bit more volume in the box if ported.

C

[---k---]

Yeah, active crossover using a Behringer to the bass bins or whatever is the best way to go in this situation.

[dmm]

Sorry the thread has been inacctive for a while. I had a total left knee replaced on the 19th. I am home now, but didn't count on how the pain affects concentration.

I will be back with further discussion shortly. Thanks for all the help guys!!!!

[cjd]

Hey, we're never in a rush on this stuff. Heal up!

(Ryan can tell you just now "not in a rush" I can be...)

[---k---]

You're usually quicker then me.

[dmm]

I'm back. Recovering from a knee replacement seems to require more time than I thought. Also, hard to focus when taking pain pills all the time.

Last thoughts were to get a good MTM and put it on top of my woofer box. So here goes.

The MTM is the Modula MTM 1 design, played with a bit, over a front mounted JBL.

What do you think of it?

[dlneubec]

Those look nice, but are you certain you want those bass bin ports aimed right up at the listener? You might be looking right into the cabinet through the ports. I would personally avoid that.

[dmm]

I guess you could be right, although they will be black and realitively long.

If I put them in the back, it might affect wall placement.

I could also put them facing down since I expect to put the bottom box on spikes.

I put them there for a sense of design.

[ThomasW]

The MTM is the Modula MTM 1 design, played with a bit, over a front mounted JBL

Below is a Modula MTM front baffle. Unless your baffle is the same size and shape, a new crossover must be designed

[dmm]

So be it then, I would just build the Modula if all I wanted to do is build a speaker from someone elses plans.

What I want to do is design a speaker that has a look and feel about it that I implanted on it. Something distinctive and elegant that will also play to an audiophile quality.

I didn't expect it to be easy. That is why I posted here, to get the best help available.

[dlneubec]

I guess you could be right, although they will be black and realitively long.

If I put them in the back, it might affect wall placement.

I could also put them facing down since I expect to put the bottom box on spikes.

I put them there for a sense of design.

:W Personal opinion warning! :W

Ports on the front almost never look good to me, with the exception of a slot port, built out of a nice hardwood, that is located low on the cabinet so you can't see more than a couple inches of the bottom side of it. Large round ports are the worst offenders, IMO, and you have them in a very prominent position with the sloped baffle angling them directly at the listener. Not to mention that any port resonanes will be that much more prominent. I fear you won't like it when you see it built.

Best of luck.

[ThomasW]

So be it then, I would just build the Modula if all I wanted to do is build a speaker from someone elses plans.

What I want to do is design a speaker that has a look and feel about it that I implanted on it. Something distinctive and elegant that will also play to an audiophile quality.

I didn't expect it to be easy. That is why I posted here, to get the best help available.

To get started I recommend you read Jon's article on loudspeaker design.

http://www.htguide.com/forum/showpost.php4?p=294580&postcount=1

[dmm]

First, let me say I try to do my research and did read all 20+ pages of the Modula MTM listing. That is why I thought I could use them on top.

This is for cjd, you mentioned that any of the RS180 designs could benefit from a bit more volume in the box if ported. There is a port in the Modula MTM's, but when I went to size a box, my program gave me something a little bigger than 1 cu ft. What do you think.

My idea, if taken to design, is to adjust some tapering on the front baffle while not changing the spacing of the drivers nor the volume of the box.

The bottom would be my JBL's, facing forward, ports on the back or bottom, passive crossover on top with plate amp driving the JBL's.

[Paul W]

Consider a single down-firing flared port. Lower air turbulence (port noise) plus slightly better boundary coupling might help the JBL on the bottom end.

[dmm]

Paul W, your Wings WTW are as handsome a speaker as I have ever seen. Nice job.

As for the port, I see no reason not to put a large down firing port in place.
Maybe I should raise the JBL up a bit?

[dmm]

Reviving my old project

It has been quite a long time since I have published my project. I could not find it posted anymore so I want to put it back out for review.

Last time out, I had decided to use the Modula One MTM for the top, with the JBL 15'' woofer below.

Two options, 2 way crossover as per the original design, with a plate amp for the woofer. The other might be to consider a 3 way crossover.

At present, the top MTM baffle is tilted 4 degrees forward, with the bottom cabinet in one of three possibilities.

Changes to the MTM include tapered sides and parallel face and back. Two wedges cut out of the lower corners to give the same relationship to the baffle board as the tapered sides above.

There is additional space on the rear of the top cabinet that will hold the crossovers and not part of the cabinet interior volume.

I have moved the 2 vents on the bottom cabinet to the rear, in addition to front mounting the woofer.

Note: I set up a radius of 10' from a height of 42" to determine the uniform relationship of the voice coils to the listener.

See drawing

Threads merged by moderator

[JonMarsh]

Are you getting ready to build now, or are you looking for feedback? The version on the left is more sculpturally interesting, but of course more complicated to fabricate- the last side profile on the right will probably work just about as well acoustically, given the wavelengths at the low frequency crossover point, and it might be preferred by some aesthetically, as it's a bit more classic.



The tapered front view is attractive, but it will have an impact on the baffle loading and baffle step in the crossover, possibly necessitating some changes in the crossover. At that point, apart from shear output level in the midrange, which would be high from even a single RS180, I have to wonder if you might not be better off using a TM variant such as the Modula MT equivalent for the top module, placing the woofer where your baffle width is 9", so things average out for it, and the tweeter just above it. If voltage sensitivity is a concern, consider the RS180-4 in instead of a single RS180-8.

Of course, considering the direction you're going here, there are other possible styles and influences you might want to consider....



Just some thoughts- the complex front baffle such as shown here for the MTM upper is easy to fabricate if you cut the baffle into sections, then glue or epoxy it back together after the facet cut steps.

[---k---]

Your models look very nice. I wish I had access to cad and the time to make those.

I didn't go through your old thread, and my memory of it is fuzzy, so maybe these comments don't apply or you've already heard them. However: If you tilt the front baffle of the Modula MTM, your listening axis will change. You might want to find yourself a nice pillow to sit on. There will also be some small response changes by changing the baffle shape.

A new 3-way crossover from will be complicated to design. Learning to get it right takes a while. I'm not up to that myself. I'd rather have something that sounds good than the satisfaction of knowing I built a turd all by myself.

That is a complicated box to build. I hope it is motivated mainly by achieving a specific appearance goal.

What is the circle next to the tweeter? You don't want the port right there, and with bass bins, you should be building the sealed version.