Cabinet for Markaudio CHN-50

[hd3291]

Hi Everyone,

I have some cute little drivers from Mark Audio: CHN50 v2, looking for a cabin design to use them.

The desired use case is for a small room with sub, so looking for a bookshelf-type design only (don't wanna try horn).

Thanks
Hemant

 

[dirtyblvd]

Have you seen these?
https://www.soundimports.eu/en/markaudio-tozzi-one-kit-red.html

 

[nandappe]

If you search, you may find a nice box.

https://www.diyaudio.com/community/search/1275184/?q=MarkAudio+CHN-50&c[title_only]=1&o=relevance

 

[GM]

The desired use case is for a small room with sub, so looking for a bookshelf-type design only (don't wanna try horn).

Greets!

OK, what sort of XO point/slope you wanting and how far away from the subwoofer will they be?

 

[vinylkid58]

I have some cute little drivers from Mark Audio: CHN50 v2, looking for a cabin design to use them.

Lots of box designs on the Mark Audio website: https://www.markaudio.com/online_shop/ch/chn-50/

jeff

 

[hd3291]

Greets!

OK, what sort of XO point/slope you wanting and how far away from the subwoofer will they be?

around 120hz

 

[GM]

OK, so ideally only ~34400/4/120 = ~72 cm/28" max away 'as the Crow flies' 😉

T/S max flat alignment:

Vented net volume (Vb) (L) = 20*Vas*Qts'^3.3 = 3.2 L

(Ft^3 = (Vb)/~28.31685) = 0.113

Vented box tuning (Fb) (Hz) = 0.42*Fs*Qts'^-0.96 = 82 Hz

F3 (Hz) = Fs*0.28*Qts'^-1.4 = 72.36 Hz

All ignoring any losses for any significant series resistance:

(Qts'): (Qts) + any added series resistance (Rs)

From this we see you'll ideally need a 4th order XO.

​

 

[hd3291]

0.42*Fs*Qts'^-0.96 = 82 Hz

Thanks.
so, I had to take the help of Google to understand this, learned new terms and now it all makes sense!
Can I directly build an enclosure? and after measuring it integrate a sub with approximately the same crossover freq where the speaker ends (considering the slope on the lower freq.)
Also Pretty much confused between the standmount ported designs (MA website). my listening position is about 1.5 meters from the speakers .

 

[GM]

You're welcome!

Since you're showing sufficient interest 👍 😎:

In 1981 the Margolis/Small design routine became increasingly popular due to it being written for an early HP handheld calculator where ~0.403 Qts' combined with the box volume [Vb] = driver compliance [Vas] and box tuning [Fb] = driver resonance [Fs], i.e. T/S max flat BR alignment, so the pioneer's ideal alignment became the cornerstone of where traditional bass reflex [BR] ends and contemporary [under-damped] speaker box design begins.

The box only loads the driver to its upper mass corner (Fhm):

upper: Fhm = 2*Fs/Qts'

lower: Flc = Fs*Qts'/2 (AFAIK only used for reactance annulled BLHs)

Qts': 2*Fs/Fhm

Fs: Fhm*Qts'/2

Maybe for some, more easily understood from a horn loading POV along with all the extra math (pg. 7):

http://www.xlrtechs.com/dbkeele.com...Preprint) - LF Horn Design Using TS Paras.pdf

T/S Explained

T/S Equations and how each one affects the others

 

[GM]

Can I directly build an enclosure? and after measuring it integrate a sub with approximately the same crossover freq where the speaker ends (considering the slope on the lower freq.)
Also Pretty much confused between the standmount ported designs (MA website). my listening position is about 1.5 meters from the speakers .

Yes, just need a vent design..........

Yes, normally the XO is the same and by 'distance' I was referring to the 'as the Crow flies' between each speaker and the sub as the farther away they are the more they sound 'disconnected' rather than a seamless blend to appear as one.

 

[planet10]

I just had an email bounce from a member with this exact question, so i will copy it here:

Any box for the Alpair 5.2/3 will work fine with CHN-50.

I have a paid planset, http://www.planet10-hifi.com/planset/A5x-extents-291117.pdf

Since that drawing i have added the wedgie versions of the µMar-KenPlus. And many other odd-balls, and a set of woofTs (helper woofers that act as stands).

The basic CGR plan is free: planet10-hifi.com/downloads/CGR-µMK-251220.pdf <http://planet10-hifi.com/downloads/CGR-µMK-251220.pdf>

Scott will have done a number of boxes:
https://kjfaudio.com/product/chn-50/
https://kjfaudio.com/product/alpair-5-3/

Most i have yet to do a proper drawing of.

And the BabyLabs set with Bloodhound: http://wodendesign.com/downloads/Woden-BabyLabs-241018.pdf

That is just what Scott and i have done.

dave

 

[GM]

So many plan/driver combos; so little time 🙁

 

[sdsddsd1]

Is there a difference other than boxshape between the CGR- μMar-Ken and the "regular" μMar-Ken?

 

[planet10]

No such thing as a regualr miniOnken. There are 5 basic shapes, CGR is one of them, and the one i usually release for free.

dave

 

[dialogbox]

Hi all! It's my first time posting here.
Thank you so much for all the information I already learned from here.

May I have a couple of questions about CHN-50 enclosures?

I'm a total noob and I just built a small box last year without any knowledge. That was based on the below slot vent box design.

https://www.kjfaudio.com/wp-content/uploads/2020/08/CHN50-slot-vent-box.png

I saw the below note about some resistance but I didn't understand that at all so I just ignored it. 😵

Alignment assumes 1/2ohm series resistance to account for typical wire, connection resistance with voltage-source amplifier.

And now I feel like I might have missed something important. What that really means? Should I have added some resistances in the middle of wire or something?

The other question is about the lagging. Some plans suggest lagging with fiberglass board or wool felts and avoid acoustic foam. But I saw some other plans (i.e. pencil 10.3 although it for the other driver) suggests stuffing with polyfill. What's the main differences between lagging the faces vs stuffing?
For me, stuffing is much easier and way easier to adjust later so I wonder if I can use the other method to get a similar result. Or the two have totally different functions?

Jason

 

[dialogbox]

http://www.xlrtechs.com/dbkeele.com...Preprint) - LF Horn Design Using TS Paras.pdf

T/S Explained

T/S Equations and how each one affects the others

Wow that's such great articles. Thank you so much!

 

[GM]

And now I feel like I might have missed something important. What that really means? Should I have added some resistances in the middle of wire or something?

What's the main differences between lagging the faces vs stuffing?
For me, stuffing is much easier and way easier to adjust later so I wonder if I can use the other method to get a similar result.

Greets!

Any resistance from wiring, XO components, etc., reduces effective motor strength (increases Qts/Qts'), which in turn increases net volume (Vb), lowers tuning (Fb): box alignment design

Just lining (doing a bit of panel reflections damping) Vs stuffing (damping entire box system), so can use less material and/or a less dense material as a popular compromise stuffing to achieve some ~ panel only damping.

 

[planet10]

CHN50-slot-vent-box

Looks to be inspired by the µMar-Ken or µFonken (he pinched my drawing of the FF85 for the drawing).

dave

 

[vinylkid58]

Hi all! It's my first time posting here.

Welcome. May the force be with you. 🙂

jeff

 

[dialogbox]

Thank you all for the prompt responses.

Welcome. May the force be with you. 🙂

Thank you! And also with you!

Any resistance from wiring, XO components, etc., reduces effective motor strength (increases Qts/Qts'), which in turn increases net volume (Vb), lowers tuning (Fb): box alignment design

Uh... I have a shortage on both English and technical knowledge so I'm not sure if I understood correctly but.. do you mean that the box is already designed to compensate those resistance of wiring, XO components, etc and it's effect? So I don't need to do anything unless I use too good wire so the resistance is too low?

Just lining (doing a bit of panel reflections damping) Vs stuffing (damping entire box system), so can use less material and/or a less dense material as a popular compromise stuffing to achieve some ~ panel only damping.

Same goes here. Sorry, I'm not sure if I understood you correctly. 😢 Do you mean I can have some flexibility on this? For example do a minimum lining and adjusting by adding/removing polyfill depending on the resulting sound?

One of the big challenge while building the previous box was this actually. I couldn't find those commonly mentioned materials here in Korea. All I could find was different products with different name. No detailed specs like density. I just used some layered felt dishcloth.

https://www.amazon.com/Universal-Household-Absorbent-Eco-Friendly-Non-Woven/dp/B094JYF33C

So I couldn't know what's the right amount. If it's ok with mixing the both, that will make it much easier for me. 🙏

Actually, I realized a mistake after I built it. I changed the shape like this to make it easier. There was no way to make the square slot hole. 😢
I liked the new shape but I think this made the effective length of the port shorter like 60cm not 72cm.

So (although the current box also sounds great)... now I'm thinking of trying a new box with this driver. Probably a little bigger one?
Also I got a pair of a10.3 so I need a box for it as well but that's out of scope of this thread.

Looks to be inspired by the µMar-Ken or µFonken (he pinched my drawing of the FF85 for the drawing).

Are they free plans? Actually not for this CHN-50 but, I sent an email to you regarding the Poplar the a10.3. I'm not sure the email found you correctly. Can you please check that?

Jason