• WANTED: Happy members who like to discuss audio and other topics related to our interest. Desire to learn and share knowledge of science required. There are daily reviews of audio hardware and expert members to help answer your questions. Click here to have your audio equipment measured for free!

Revel M105 Copy DIY build

TulseLuper

Active Member
Forum Donor
Joined
Oct 1, 2019
Messages
272
Likes
453
Location
Illinois
And here is the as-built for comparison to the simulation above. At this stage I only had time for the 1 measurement, will do full spins next weekend.

View attachment 231867

+/- 1dB within the limitations of the 4ms window. Unbelievably flat for a passive. Both speakers tested red and black, they only deviate by 0.25db max.
Awesome work. Any update on this with spins? Looking to build the version with ScanSpeak woofer soon.
 

TulseLuper

Active Member
Forum Donor
Joined
Oct 1, 2019
Messages
272
Likes
453
Location
Illinois
C7A0200B-52D2-4824-B310-98123243E20B.jpeg


Should have three of these (LCR) finished soon. The waveguides from i.materialize came pretty splotchy looking, so I might spray paint them.
 

TulseLuper

Active Member
Forum Donor
Joined
Oct 1, 2019
Messages
272
Likes
453
Location
Illinois
Boxes are done but still waiting on some parts to finish the crossovers (which are large). Thanks again to McFly for offering up the plans, and I'm anxious to hear these soon. 18mm Baltic Birch exterior panels (cost doubled in the last couple years where I am :mad:) with a 1/2" MDF vertical brace. Baffle and back panel were cut out with a Shaper Origin. Finish is 2 coats of General Finishes Flat Out Flat, which is basically invisible - very matte finish with no wood darkening effect.

IMG_4230.jpegIMG_4233.jpegIMG_4273.jpegIMG_4322.jpegIMG_4327.jpegIMG_4326.jpeg
 

somebodyelse

Major Contributor
Joined
Dec 5, 2018
Messages
3,550
Likes
2,833
What's the router model? I've seen similar movable CNC devices but don't know that one.
 

TulseLuper

Active Member
Forum Donor
Joined
Oct 1, 2019
Messages
272
Likes
453
Location
Illinois
What's the router model? I've seen similar movable CNC devices but don't know that one.
It’s the original Shaper Origin. I preordered it before launch so got a good deal. Festool makes the router spindle, Shaper makes the rest. It’s Wi-Fi connected and takes SVG files you upload to your “Shaper Hub” (or you can design basic shapes/text/joinery on the device itself). It’s not exactly fast to use but has been extremely valuable in my shop.

 
OP
McFly

McFly

Addicted to Fun and Learning
Joined
Mar 12, 2019
Messages
901
Likes
1,852
Location
NZ
I hope to have some updates on this in the next few weeks.

Edit:

Rest assured I have not abandoned this project. What has abandoned me is the weather, more on that later. The plan was to build them (i did), live with them through the winter (i did) and try and tweak and tune them as time went on, then post the finished and finals on both the paper woofer scan speak version and the SB acoustics Al woofer version around now. The schematic post 118 is still the latest and greatest for the scanspeak woofer, and I have zero complaints about the speaker other than - its a bookshelf, and I want floorstanders. Other than that, subjectively to me it is absolutely perfect. As these were my mains (I was daily driving them, tv, music everything) the floorstanders need to be built first to replace them also. I completed these just last month, so now have the time to go back to the aluminium woofer version I posted originally in this thread with more knowledge and also complete that design.

I see a couple people are following or attempting these designs so I need to get my ass into gear. One problem. The weather here. Has. Been. BAD. Like, cant really go outside bad. Pretty much, every freaking day. And its our summer, which is normally stinking hot beach days 80-90% of the time (Seems to be a bit of this going round worldwide, funny eh?).

So bear with me. When it dries out, and it will, I will be much more active with the speaker work. These designs deserve finished and final revisions.
 
Last edited:
OP
McFly

McFly

Addicted to Fun and Learning
Joined
Mar 12, 2019
Messages
901
Likes
1,852
Location
NZ
Boxes are done but still waiting on some parts to finish the crossovers (which are large). Thanks again to McFly for offering up the plans, and I'm anxious to hear these soon. 18mm Baltic Birch exterior panels (cost doubled in the last couple years where I am :mad:) with a 1/2" MDF vertical brace. Baffle and back panel were cut out with a Shaper Origin. Finish is 2 coats of General Finishes Flat Out Flat, which is basically invisible - very matte finish with no wood darkening effect.

View attachment 263128View attachment 263130View attachment 263131View attachment 263132View attachment 263129View attachment 263133
Looking sick!!

I recommend, although its not a must, getting a bit of gasket paper (automotive stores) and making a gasket for the tweeter waveguide. Also can help with bringing the waveguide flush with baffle if needed/desired. This is more desirable if the speaker is a sealed design.

And also, I strongly recommend this, seal the edge of the tweeter to the waveguide with blu-tack or similar, pictured below. This will stop the woofer pressurizing the back/front side of the tweeter dome, creating tweeter IMD that is easily avoidable.

20210702_161604.jpg
 

zman01

Member
Joined
Feb 7, 2021
Messages
46
Likes
65
Good tips McFly.

TulseLuper,

You build is coming along nicely. What port are you using?
 

TulseLuper

Active Member
Forum Donor
Joined
Oct 1, 2019
Messages
272
Likes
453
Location
Illinois
The schematic post 118 is still the latest and greatest for the scanspeak woofer
This is what I used - can't wait to wrap it up.

gasket for the tweeter waveguide
Planning on it. I thought I had this laying around as well, but had to wait for a delivery. If you look close, the waveguide is recessed by a small 1/16" into the baffle. After the tape which is almost 1/8" thick before compressing, it will be precisely flush with the baffle. I'll also put a gasket under the flange for the port just to be sure it doesn't vibrate or leak in the wrong spots.

seal the edge of the tweeter to the waveguide with blu-tack
Very good to know - I had not seen this before and will do that.

You build is coming along nicely. What port are you using?
Thanks zman. It's a 2" Precision Port. I do not remember the length, but can measure and get back to you when I'm home from travels. My internal box depth is 10.5"/267mm, and I made the port as long as I could without it seeming too close to the back of the tweeter.


A general question: any recommendations on fixing the x-over board to the bottom of the cabinet while allowing for it to be removed? On another build I used a screw in the front which you could access with a right-angle driver attachment and extension but that was a bit of a pain. I was thinking of trying industrial velcro this time, rated for 50lbs or something. I have to ship them across the country so want something strong but not permament.

Hope the weather turns up soon @McFly, for your own sake.
 

zman01

Member
Joined
Feb 7, 2021
Messages
46
Likes
65
McFly,

Been reading about the bad weather in NZ and how it's hampering preparations for the England and New Zealand cricket teams as the Test series gets underway...

Stay safe and hope the weather clears up soon.
 
OP
McFly

McFly

Addicted to Fun and Learning
Joined
Mar 12, 2019
Messages
901
Likes
1,852
Location
NZ
Im not sure, I just managed to put my XO board onto the bottom of the inside of the cabinet by using 1" wood screws and a really stubby screwdriver. Not easy but it worked. Removable, slowly.

Its not this current storm that's the problem, we've had loads of them!! (this one a bit more severe). One reigon of NZ has declared 'state of emergency' for the 9th time this summer! (lasts 7 days). I'm not complaining, were safe, and I feel a lot more for the turkish at the moment. I just cant get anything done around here!
 

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
4,689
Likes
4,550
Location
Sweden - Слава Україні
Thanks zman. It's a 2" Precision Port. I do not remember the length, but can measure and get back to you when I'm home from travels. My internal box depth is 10.5"/267mm, and I made the port as long as I could without it seeming too close to the back of the tweeter.
Here's a tip on something a DIYer can build when it comes to gates. All to avoid turbulence. It is apparently a very effective solution. In this case, 15 degree angulation at both ends of the gate:
slitsritning.jpg


This is how it looks with that construction. You may recognize the midrange, tweeter with WG that is the speakers::)
IMG_4299 (2) (7).jpg

(not my speakers)


For those who are interested. A little about gate theory. From a person who works professionally with similar designs:
(translated via google translate so it may not be a completely optimal translation)

The Reynolds number inside the port need not be low because the flow changes direction. It is enough if it stays below approx. 20000-100000 for extensive turbulence to be avoided there for a gate with normal surface roughness. Estuaries are considerably more complicated, however.

It gets very messy to mix wave theory with fluid mechanics. Then you have flow acoustics, which is extremely difficult to model, which is why you prefer to leave the flow part out of the whole thing as far as possible. Fortunately, this works well for bass reflex ports up to high sound pressure levels. This means that if you have good control over the dimensions included in the construction, including varying port cross-sections, you will obtain a very good estimate for the port resonance frequency even with the usual simplified theory.

Directly outside the port mouth, one has essentially only normal hemispherical wave propagation for a source that behaves as an ideal circular piston with a circumference smaller than the wavelength (applies up to high sound pressure levels).

One can neglect boundary layers, turbulence and other flow-related things up to flow/particle velocities of around 10 m/s and often more. Anyone who wants to build a bass reflex speaker does not necessarily need to bother with it, but can just put together a reasonable port. However, one must keep in mind that the cross-sectional area of the gate increases at the funnels and take this into account by slightly increasing the overall length. However, normal funnels do not have a completely optimal shape, although they are significantly better than sharp edges.

If you really want to optimize the gate properties, you have to make sure you have a carefully shaped transition to the baffle. Below you can see such a shape for a slot gate, where the flow rate is calculated via FEM (according to Bezzola's method https://www.comsol.com/paper/download/679311/bezzola_paper.pdf). The very smooth shapes of the constant velocity contours show that this port shape requires extreme flow velocities to generate rotating flow, i.e. turbulence. You can clearly see how the flow is slightly accelerated along the curved limiting surfaces in the gate to transition into a smooth, neat course outside the gate mouth.

tokopt (1).png


 

Attachments

  • E095C7A1-0F01-476A-8F60-67B2205A351C.jpeg
    E095C7A1-0F01-476A-8F60-67B2205A351C.jpeg
    110.9 KB · Views: 76
Last edited:

TulseLuper

Active Member
Forum Donor
Joined
Oct 1, 2019
Messages
272
Likes
453
Location
Illinois
Good to know @DanielT. Precision ports have a very large flare, these will be hi-passed, and they're in a small room. So I doubt I'll have problems, but will note this for future reference. Slots are often convenient for placement/box design.
 

DanielT

Major Contributor
Joined
Oct 10, 2020
Messages
4,689
Likes
4,550
Location
Sweden - Слава Україні
Good to know @DanielT. Precision ports have a very large flare, these will be hi-passed, and they're in a small room. So I doubt I'll have problems, but will note this for future reference. Slots are often convenient for placement/box design.
Those are the benefits of DIY. To build custom ports (instead of something generic similar to circular PVC pipe), maybe mirror flip tweeters on the baffles of the speakers (not to center the tweeter to reduce diffraction effects) and so on. :)

OT
Hope it's ok with you McFly to bring up a bit about subwoofers and ports in your thread?
For sub bass/low bass boxes I would definitely look into this slotted port. Here's an example of it with the superb driver:


A subwoofer DIY with that driver.Two BMS 18N862 even. :oops:
Apologize to neighbors? Nice if you can use the potential in two 18 inchers in your home in and of itself. You can check the thread. Many pictures and measurements.:)

Färdigt.jpg

Title:

Ported box for BMS 18n862
Posted by Anders » 2021-09-20 23:24

Hello,

Got hold of two pieces



Low distortion, it's a really good driver apparently:
Measurement element percent distortion.png
 

Attachments

  • Measure element.jpg
    Measure element.jpg
    1.8 MB · Views: 106
  • Slitsportbörjartaform.jpg
    Slitsportbörjartaform.jpg
    211.9 KB · Views: 107
OP
McFly

McFly

Addicted to Fun and Learning
Joined
Mar 12, 2019
Messages
901
Likes
1,852
Location
NZ
Finally - here are my cabinet measurements. Obviously not scaled, made in MS paint.

M105 COPY REV 1.jpg


@TulseLuper 's cabinets look pretty much spot on. Wouldnt matter if the measurements were a mm or two out, wouldnt be the end of the world, just have fun trying to get that waveguide centered and level!!

Also dont forget a full front to back side to side window brace in between the woofer and the tweeter similar to pictrured
1676962745979.png
 
Last edited:

TulseLuper

Active Member
Forum Donor
Joined
Oct 1, 2019
Messages
272
Likes
453
Location
Illinois
I will post a drawing from CAD to your dimensions when I’m back at my computer, but I think people will prefer your remarkable MS Paint version.

My brace is top to bottom because in one iteration, with the huge precision port flanges, it didn’t line up front to back. I think front to back would fit in my final version. Seems better that way for the extra bracing on the baffle and the space on the bottom for the crossover.
 

zman01

Member
Joined
Feb 7, 2021
Messages
46
Likes
65
I will post a drawing from CAD to your dimensions when I’m back at my computer, but I think people will prefer your remarkable MS Paint version.

My brace is top to bottom because in one iteration, with the huge precision port flanges, it didn’t line up front to back. I think front to back would fit in my final version. Seems better that way for the extra bracing on the baffle and the space on the bottom for the crossover.

How are the CAD drawings coming along? I ask, as I might fancy taking the help of a CNC shop for the baffles.

Have you been able to do some critical listening to the speakers?

Thank you.
 
Top Bottom