10F/8424 & RS225-8 FAST / WAW Ref Monitor

[Plott]

@xrk, I've heard it now with earphones and it sounds really great!
You showed us in March 2020 a version with the Visaton B80 with modified XO, is it for the monitor only or for the floorstander too? Decision has been made, this will be my next project

 

[xrk971]

You can use B80 with the floorstander TL as well.

 

[xrk971]

Forgot to mention that Zman01 made the floor standing TL with the B80 and it’s crossover. In fact, it was Zman01 who urged me to develop the XO for the B80 variant. I have a sealed 24L FAST with B80 in my basement exercise room with a 10in Polk self powered sub. That combo works very well too.

10F/8424 & RS225-8 FAST / WAW Ref Monitor

 

[Plott]

Thanks a lot @xrk!
I am on vacation but have now ordered everything, the woodwork begins next week.
What is the rear opening for, it was'nt there in the original plans?

 

[growing]

Hey there,

I'm relatively new to speaker building, only having build a few kits, but really interested in giving these speakers a shot.

I'm most interested in building the smaller, sealed version and had a few questions I was hoping someone might be able to clarify for me

I saw the nicely drawn CAD file for the taller tower, but does something like this exist for the sealed version too? I'd like to build a pair using 3/4" baltic birch or veneered MDF, and looking for a few of the key measurements to help with the build!



Along the same lines, would anyone be able to provide the baffle measurements, like placement of the speakers on the baffle, and in relation to one another?



I'm also happy to help create a CAD or technical drawing of the smaller box if the measurements are provided somewhere.



Much appreciated for any and all info, and really looking forward to building a pair.

 

[xrk971]

@growing,
You will find all you need on post 1. It’s a rectangular box of 24L internal volume, 10in baffle width, driver CTC spacing of 7in. Use 18mm BB plywood for the baffle. Use a sports cone for the full range rear chamber. Or make a Dagger rear chamber out of thin plywood.

From 1st paragraph in Post 1:

The design ended up as a 24 liter volume for the woofer and a 1.1 liter 3-sided pyramid Dagger for the 10F/8424. The important external dimensions are: 10in wide baffle and 24 liter internal volume (sealed). You can make the height and depth to suit your individual case, but it will need to be deep enough to house the Dagger. The internal dimensions I settled on were 8in wide x 12in deep x 16in tall. The short sealed TL is made of three 6in wide x 12.5in long triangles.

@Plott: the rear door is for the XO and Zman01 did that on his own. You can mount XO inside the main chamber and that saves a lot of cabinet work.

 

[growing]

@xrk971 - thank you for the reply. I had missed the center to center distance so that is quite helpful.


If I'm understanding correctly, the overall cabinet dimensions are not so important, so long as the speaker center to center distance, baffle width, and internal volume all meet the listed requirements.


I created a quick model based off of the dimensions you used, slightly increasing the internal width to 8.5" so that I can use 3/4" plywood for the cabinets (10" baffle width minus 1.5" of plywood), and decreased the internal depth to 11" to compensate for the added volume. This puts the internal dimensions at 8.5" width, 16" height and 11" depth, for a total of 24.5 liters.


Does this all look good, or is there anything I may be missing?

 

[audiostar]

xrk971,

I did not know you were on YouTube, smart move.

 

[xrk971]

@growing,
That looks good.

@audiostar,
It’s a recent thing - and I might start adding more how to videos or more sound clips of my speakers.

 

[Plott]

Thank you @xrk!
Just a few more questions
Your prototypes from StudioMic used acoustic foam, but your last picture shows felt, which one is better? Should/must be the cut-outs for the speakers recessed or can the speakers be mounted just on the front panel?
Must the cut-outs be chamfered?
Thank you in advance

Cheers

 

[xrk971]

Either eggcrate foam or felt works. Felt might attract moths. Foam is less expensive I think. Drivers should be flush mounted and chamfered on back side for best smooth airflow. The felt was done by Zman probably because that is what he had locally.

 

[zman01]

I used the felt because I had some on hand, and in my case used jute felt - to my knowledge this type of material doesn't attract insects.

However I am guessing that the eggcrate foam would be easier to source in most places of the world, and also easier to apply/fix inside the cabinet.

Attached is a picture of the chamfer that X mentioned in his last post.

 

[Plott]

Thanks @xrk!
I don't like moths so I choose foam and I could have a dedicated 1,5in speaker foam, not egg crate shaped, but rather pointed as you can see it in the attachment. Would it be okay?

Thanks @zman too!
As I see the cut-out will cause the biggest problem, because I don't have the machinery for it. But the picture helps.

 

[Plott]

Forgot the last question: is the 80 mil butyl sound deadener a must? Is there a difference with and without?
Thanks in advance, again.

 

[xrk971]

A file (or very course sandpaper) and elbow grease works to make the chamfer too. Do what you can. It’s not an absolute must.

The butyl is also nice to have but not absolute required.

Your foam looks perfect. Very pointy tips. Probably better than eggcrate foam.

 

[Plott]

Great, many thanks for your answer @xrk!

 

[xrk971]

Hi Plott,
This is a 40w Class A amplifier that drives the 10F/RS225 FAST speaker very well.

Alpha Nirvana 39w 8ohm Class A Amp

As you know, I am also working on a 100w Class A amp for it.

 

[Plott]

Hi xrk,
thank you, I will check it. I saw your 100w amp too, and it looks (and sounds) really good. So many options now

 

[as8912]

Feel like it's months overdue for an update here. Truly awesome sounding speakers, impressive sound stage, very clear reproduction and disconcertingly clear bass, easily the best speakers I've heard. Had a number of friends listen to it who have high end setups and they've put the rough sound quality in the $9k+ range. It's been months since I've had these running and I'm still taken away with the quality of the sound.

Find pics attached, I'm planning on making a matching tv stand at some point (similar to this maybe?), but I'm happy with the speakers as my first woodworking project lol.

On the amp side I have the settled on the following, works basically perfect for me:

Audio:
Ethernet to Volumio on Rasp Pi -> USB to Topping E30 -> Dual mono FH9HVX amps w/ All Cee’s Class AB PSU

Video:
[12TB NAS -> ethernet to KODI Matrix on Rasp Pi -> HDMI to] TV -> Optical to Topping E30 -> Dual mono FH9HVX amps w/ All Cee’s Class AB PSU

 

[as8912]

If you're interested in the CNC files for the above, please find here. I added ~5" if I recall correctly, which just formed a dead space at the bottom you could put additional ballast.

Chamfering/details required a couple of days of planing and post processing to make it all flush, so you've been warned.