FAST speaker build (TC9FD18 & RS225-8)

suraj

Active Member
Joined
Feb 26, 2013
Messages
103
Points
28
Location
Mysore
Hello,
I have finally started work on my FAST speaker project and decided to open a thread to document my progress and also take help from the community,since this is my first such build.
Now,I have some experience helping a relative in his furniture manufacturing shop but that was 18 years ago,so I am starting afresh.

I always wanted to have a speaker system of my own and came across the this cheap driver,the TC9FD18-08 on DIYAUDIO.The plan was to have a running system speakers,amp and all for under 10k.but,it turned out that making a decent looking cab would cost me a decent amount in itself and the cheap amp from ebay never arrived.
So,I decided to upsize and was attracted to the FAST speaker concept.Then came along this thread

https://www.diyaudio.com/forums/full-range/273524-10f-8424-rs225-8-fast-waw-ref-monitor.html

So,I went ahead and purchased the woofers,but one of them arrived damaged. A replacement woofer was requested but it took six months to arrive. Still,not too bad. Then,the miniDSP required for the active crossover was lost in transit and the amp I meant to use for bi amping was never built,and the entire project was forgotten for a few years.
Then,I saw a couple of threads here where chaps actually completed the same project,though in different configurations and I got the itch to restart my project after fellow DIY-er soundnovice asked to buy the woofers off of me.
Luckily,another fellow DIY-er Sadik was kind enough to provide me with the panels in cut form and my project is going to finally start!
woo hoo!

So the drivers are these
Full range-Tymphany TC9FD18-08
Woofer -Dayton RS225-8

I will be making the passive crossover version as I dont want to spend $ on getting the miniDSP again, though the speaker binding posts have provision for bi amping.
The cabinet will be sealed.Assembling the cabinet should be easy enough but finishing them to look good seems to be my main challenge now.

Anyhow,I am collecting materials for my build-tools that I require,damping materials,adhesive,crossover parts,paints,veneers etc.
Hopefully all work will be done by myself without any need for a carpenter.

Here are the things i am getting
1. Eggshell acoustic foam from MMT acoustix-https://www.mmtacoustixonline.com/product-page/egg-tray-acoustic-foam-6-x3-charcoal
2. Butyl damping sheets from dampmat-https://www.dampmat.com/
3. Araldite for gluing-https://www.amazon.in/gp/product/B00NYK61KQ/ref=ox_sc_saved_title_3?smid=AZ7ENP8SWCBT8&psc=1

any comments on the above?

I'll post about the tools and other things as I go along.


Suraj

So,here is my first challenge
the full range speakers are not exactly a fit for the flush speaker cut out which is bigger than the speakers themselves.How do I work with that?My first thought was to neglect it as the TC9FD are not so good looking drivers and they will be covered by the speaker grille cloth. But then, I must do it.
heres how it looks-
TC9FD gap

It is what it is,so how will I fill up the gap? putty? keep some foam pieces there and cover it over with the veneer?


Then,one of the front panel cut outs is a tad too small for the woofer.
woofer fit

Suggestions on how to enlarge the flush mount hole,without using power tools/professional help?a bit of material needs to be removed from the area marked in red.
Now that I think about it,the woofers are a tight fit,once cabinet finishing is done,with the thickness of the added fillers and paint,the woofers will not fit and the hole will need to be enlarged.
How do I proceed? Also,how do I add images here?
 
Hi Suraj,

The Gap should be there for easy disassembly of full range speaker. its not an issue to worry for. I have used the same profile while cutting in the black enclosures.

The worry part is about the fitment of woofer. Did you checked the fitment of same woofer in another panel is the fitment ok. If it is a little error then it can be sanded easily with 150 grit sand paper, as MDF is very easy to work with.

To sand the extra MDF do as below.
1. Take a Brown packing tape of 1" size Like This or something circular
2. Cut a strip of 150 mm grit sand paper (same width as the tape) and stick the same on curved side of tape.
3. Then sand it lightly on complete round cutout. it will not take a long to get the size.

And I am sorry for this issue. I Hope this will solve the issue.

Sadik
 
Hi Suraj,

The Gap should be there for easy disassembly of full range speaker. its not an issue to worry for. I have used the same profile while cutting in the black enclosures.
so thats intentional.

The worry part is about the fitment of woofer. Did you checked the fitment of same woofer in another panel is the fitment ok. If it is a little error then it can be sanded easily with 150 grit sand paper, as MDF is very easy to work with.

To sand the extra MDF do as below.
1. Take a Brown packing tape of 1" size Like This or something circular
2. Cut a strip of 150 mm grit sand paper (same width as the tape) and stick the same on curved side of tape.
3. Then sand it lightly on complete round cutout. it will not take a long to get the size.
aha!
I did think of sanding it down,but was unsure if the circle would remain a circle anymore.The tape jugaad is something that only a experienced person like you can think of.Now,If I can find a metal lid from a dabba,it would be really handy.

And I am sorry for this issue. I Hope this will solve the issue.
Dont be sorry.it isnt DIY if it is too easy!;)
like you told me before,it is all about how I deal with issues and work around it.
 
So here's a update on the progress of work. Not much happened for the last few weeks since I was on travel again.
In the mean time, I've been collecting materials and have everything required to put the cabinets together-clamps, adhesive, the inner damping materials.

I was testing some old epoxy adhesive and the results turned out to be dubious. I used loctite brand epoxy which I had and a trial taken on some scrap wood has shown poor results. IMG_20190519_115716.jpg
On pulling the two pieces apart, the adhesive separated and the two pieces are intact. It was kept to cure for 24 hours.
1. I did not clamp the wood pieces together
2. The epoxy is about 3 years old.

So I purchased araldite which is of recent manufacturing date and took another trial this time with clamps to keep the pieces together till it cures.
Any suggestions on how to avoid joint failure?

This is of particular concern because I have to stick the cone together and I have no means of clamping such a shape. However, I thought of using a old jar to weigh down the cone during setting. Any suggestions?
IMG-20190518-233506.jpg


Here's the rubber damping sheet-IMG_20190518_234803.jpg
IMG-20190518-234407.jpg


And another issue in which I need guidance- I did a dry fit of all the panels and find that the front face is a little bigger than the rest of the cabinet by 1.5 mm or so. Is it designed on purpose or I have to shave off the excess? How can I trim it off? Using a router? table saw?
IMG-20190518-233735.jpg
 
And another issue in which I need guidance- I did a dry fit of all the panels and find that the front face is a little bigger than the rest of the cabinet by 1.5 mm or so. Is it designed on purpose or I have to shave off the excess? How can I trim it off? Using a router? table saw?

There will be a little bit plus minus in sizes, if the front face is little bigger then you can flush it off with help of router or planer. You will have to adjust it in such a way that it is equally outside from all sides and then with help of 80 grit sand Paper it will not be difficult to sand the extra mdf. Just make a sanding block with help of sand paper and wood or any other plain surface. Stick the sanding paper to the wood block with help of double sided tape or the araldite and your sanding block is ready. (This operation to be carried only after gluing the work piece together)
 
Sorry for the late reply.
You know my schedule,Im on tour frequently,and was unwell for some time in between too. Anyhow,the cabinets have been glued together for almost 75% completion.I need to get back and get a little planing of the edges done.I shall post photos tomorrow.

In the meanwhile,I have been collecting parts for the crossover and also for the amp build too.Ran into a little issue with getting the inductor,for the price I wanted.Sorted that out too.
 
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So,here's a delayed update.Used the holiday to get things moving along
state of the build
1.jpg
here is one issue which had held me up
IMG_20190810_212459.jpg

I was not able to set the top panel for a flush fit. because some panels were a bit higher than the others.
So,I just used some 80 grit sandpaper and sanded the high spots flat.So,now the top panel now sits flush.Took some time but it works.
So, decided to stick the dampmat sheets in before progressing any further and heres the current state of affairs
IMG_20190815_182027.jpg

Though now I've run out of dampmat (just need 1/2 a sheet more!) and need to order it again.:p
 
So now that I have everything needed to complete the build, including parts for the crossover, I started to glue foam sheets on top of the rubber sheets.
Now, I am trying to stick foam to aluminium .
I have fevicol sr which I used to stick the rubber sheets to wood, but it will melt plastic and foam.
Then I tried using white fevicol but it does not stick well and the foam peels off by itself or else the bond is weak. The internet says to use contact cement but I cannot use what I have.
A quick search throws up this-fevicol foamfix. I'll try to get it locally else I'll go for the foam adhesive sold from where I got my eggshell foam.

Any better suggestions?
 
So,here's a update,after more than a year!

IMG_20200409_170956.jpg

and the speakers all setup!

IMG_20200412_161724.jpg

I need to finetune the crossover to my liking and then finish the speakers by painting and or veneering the exterior.wonder how long that will take!;)

Anyhow,as of now,most of my DIY stuff is in storage.I was too lazy to pull out my amps,dust them off and check if they still work as most are in pieces.So,I used that opportunity to finish off another amp the Gmarsh wiener TPA 3118.This amp project is just as long running as my speaker project as I had originally planned to bi-amp the speakers,so,I have two of them.

Arent they cute?(with a 9v battery for scale)

IMG_20200417_154606.jpg

Though since I am using a passive crossover now,I am using only one of the two boards and they are great!The speakers play as loud as I could want without needing the full turn of the input pot from my preamp. One can argue how they aren't really audiophile but Im really pleased with the sound.

Coming to the pre amp,here it is!A Pass Korg B-1.Perhaps I should have ordered more audiophile parts and golden caps,but I probably couldnt tell the difference.

IMG_20200409_165344.jpg

IMG_20200409_153030.jpg

Many thanks to @sadik for helping me out with the cabinet.
Without him,I would have probably never made these speakers.
 
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Hi Suraj, what was the final outcome of this project? If completed can you share some images and your experience. I have pair of Mark Audio CHR-70-Gold Gen3 kept unused since last 4 years. I was thinking that the Ported BS will not do justice for low-end, whereas I do not have expertise to build Folded Horn Tower model to extend the Bass, and also space constraints to place it even if I take a help of Carpenter. Following your thread so I can make use of those FRs in some other hybrid way. Just curious about the final build of yours.
 
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