Flat Wall Mount Stereo MLTL using TC9FD's (2)

I plopped in a pair of Dayton PS-95s in my foam set. I like the TC9s a lot more. The PS-95s need some EQ to tame the top end, and even with some EQ, they sounded more "grainy". They may have had a bit more detail and more punch, but the TC9s are so smooth...they simply don't do anything offensive.
 
Hi X!

I got a question at work if I could have a speaker workshop (~4 hours) to show people what speaker building is and I'm contemplating if it's possible to let people build a set of wall mount TC9 MLTLs in that timeframe.

If the result is supposed to be something that the participants can use in their offices the speakers need to be compact and be able to both be wall mounted as well as stand on a table (against a wall).

Using foam core is a must and I'm thinking that a front/back that is a whole sheet speeds up the process considerably. The available sizes here are 420*297 mm (A3), 500x350 mm and 594x420 mm (A2). We have decent A3-printers and I'm thinking that if the front is A3 format we can let people print whatever they want and glue on.

I'm guessing you've used 5 mm thick foam core and that measurements are external. From your sketch I get a CSA of 92 cm^2 and the lengths 31 cm and 50-60 cm (difficult to measure due to geometry). The CSA of the port is 14 cm^2 and length 6.2 cm. If I input these into hornresp I get this response (for L23 = 50 cm, and a total of 10 g of polyfill to section 1 and 2)
xrk_mltl_L23_50_poly.png

If I just reduce the outer dimensions to an A3-paper size (420x297 mm), increase inner depth to 6.5 cm and increase the length of the port to 9.5 cm I get an near identical result. Only difference as far as I can see is that maximum output before xmax reduces 1 dB.

Could you run these in your akabak-model?

My sketch looks like this:
sketch.png

/Anton
 
Hi X!

I got a question at work if I could have a speaker workshop (~4 hours) to show people what speaker building is and I'm contemplating if it's possible to let people build a set of wall mount TC9 MLTLs in that timeframe.

If the result is supposed to be something that the participants can use in their offices the speakers need to be compact and be able to both be wall mounted as well as stand on a table (against a wall).

Using foam core is a must and I'm thinking that a front/back that is a whole sheet speeds up the process considerably. The available sizes here are 420*297 mm (A3), 500x350 mm and 594x420 mm (A2). We have decent A3-printers and I'm thinking that if the front is A3 format we can let people print whatever they want and glue on.

I'm guessing you've used 5 mm thick foam core and that measurements are external. From your sketch I get a CSA of 92 cm^2 and the lengths 31 cm and 50-60 cm (difficult to measure due to geometry). The CSA of the port is 14 cm^2 and length 6.2 cm. If I input these into hornresp I get this response (for L23 = 50 cm, and a total of 10 g of polyfill to section 1 and 2)
View attachment 670469

If I just reduce the outer dimensions to an A3-paper size (420x297 mm), increase inner depth to 6.5 cm and increase the length of the port to 9.5 cm I get an near identical result. Only difference as far as I can see is that maximum output before xmax reduces 1 dB.

Could you run these in your akabak-model?

My sketch looks like this:
View attachment 670468

/Anton
Well, I made a pair and didn't like the low tuning that caused all output below 100 Hz to be 10 dB below rest. Measured standing against a wall, on axis.
TC9 MLTL orig, 1 m, 0 deg.jpg

So I opened it up and cut off 4 cm of the port and got this result. Here measured laying on floor (middle of 20 m^2 room) on axis, 1 m distance:
TC9 MLTL mod, 1 m, 0-45 deg.jpg
Those are some nice polars for a 3.5" driver, looks almost like a tweeter with a small waveguide :)

The dip in the 200-500 Hz area reduces if I move the speaker slightly, so it's likely caused by reflections:
TC9 MLTL mod, 1 m, 0 deg, moved.jpg

No gating in measurements.

Here is distortion at ~71 dB:
TC9 MLTL mod, 1 m, 0 deg, dist.jpg
Sweep sounds clean at these levels.

And at ~91 dB:
TC9 MLTL mod, 1 m, 0 deg, dist high.jpg
Audible distortion (rattle) below ~150 Hz. But -50 dB above 500 Hz at 91 dB is respectable.

Lastly, a few build pics:
20180329_232237.jpg

20180329_232453.jpg

20180329_232630.jpg

20180330_000157.jpg

Nice speakers, appreciated by my family when I brought them on a skiing trip.

/Anton
 
The 4FE35 is s bigger class driver and dimensions need to be simulated. Do you have them already? 3FE25 could be dropped in and work fine.
Hi xrk971, I know this was asked before. It's possible for you to simulate wall speaker for Faital Pro 4FE35 - 4ohm ?
Got a pair of them and cannot find a suitable design. Have tried them in Tabaq and they don't sound so good. Looking at diyaudio forum there is no suitable designs for this driver.

Thanks in advance. Screenshot_20200122-201900.jpg
 
?
1"*2.2"=2.54cm*5.588cm=14.2cm2
4cm dia -> 12.6cm2
2cm dia -> 4.9cm2

sorry I'm sitting in the garage with an android tablet and cannot write formula properly.
I do not find my notes nor postings from back when I did the first build.
If the vent goes smaller in diameter, does the length have to be shorter or longer?
 
FLAT Folded wall mounted build

Flat folded MLTL build

After visiting with XRK, I decided to try this diminutive little driver, hoping for the best.
Bypassed the foam core option for 1/2" plywood....why waste my time? Others have tested the waters and came out fine.
I also made mine upside down...I wanted it to be just-over-monitor heigth, so the speakers would be closer to ear level and yes, the vents shoot up.
Also added a 1" taller back, as that gave me added material to screw it to the studs. It does weigh a little bit now.
I did change the dims, as I went full 2.50" internal enclosure depth, 2.50" tall on my vents by 2" wide, but kept the 1" dimension.
I also added 1/2 X 1/2" stock to my plywood faces, internally, to brad and glue it all together and not chance splintering the 1/2" plywood.
My pictures show my attempt with a sort of gasket material I had on hand, as I knew I wanted to screw the top baffle down just in case I go in later.
I then discarded two attempts, and just glued it all down then using screws. Reason to follow.
R-13 building insulation was used. I had it and think it does a superb job.
My hair brained goal seemed righteous...I wanted killer sound at the new office. I also had family pictures that I could not put under plexiglass anymore. I turned XRK's "stand alone" wall mount into a picture display. Now I have pictures up and out of the way AND killer sound.
So I screwed the baffle down and used little magnets to hold my family pictures. Win Win.
Did the 45 degree bevel around the speaker openings, as I mounted the TC9FD's from the rear.

My inital test at home was OK. Set it up on a milk crate, used a 4ohm rated T2024 amp and threw in some CDs in minimalist Naxa DVD player.
Set back at about 5 feet to listen, and was pleased. No stinkin coils, no stinkin caps, just free breathin. 10 or so songs in, got up to answer the phone. Came back and hit a room mode at 12 feet from the cabinet....Holy Crap, where's the sub? This thing was awesome at this range and not very loud!
Kinda like having the LOUDNESS knob on older receivers, up just a bit. Really surprising! Now remember my vents point up and it was resting on a milk crate with vents 64" from the ceiling and about 42" from the nearest side wall. I just grinned ear to ear!

So next hurtle was mounting above the monitor at work. Ends up the vents are 26" from ceiling and I normally sit back about 42" during the day.
Side to side, it encounters left wall at 23" and right wall at 69". That's just how it is, here.
I now have moved to the BT enabled FOSI Audio ZK-1002 mini amp. BT works well for the office as I had quite a bit of computer noise with the 3.5mm line in. Probably a proximity thing.
So the real test: Office background music is really nice. Full, maybe slightly warm bodied, highs are there but use to a little more. BUT, we have to remember the intended use here. Office background music. Can I listen for hours....you bet. Hear the music and just listen for musical highlights...yep. But it's for the office!
If you set back at 80" and add a little V, they start singing again with that hint of a sub. I'm very pleased.
I use a number of phone loaded tunes and you can tell the ones that are not recorded as well....CDs too.
I mostly listen to Slacker Radio and the jazz stations are good, for the intended use. Some Rock is good, others are thin. But that's OK...in the office.
I finished it with a Hammertone Copper but wiped most of it down. Thinking Hammertone should only go on metal?
I tell everyone that it's "Nova Scotia barn wood" wink wink. They don't know...
Don't completely judge a book by it's cover....it's a worthy read.
 

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