Proac Studio 100 - DIY

[Whoops]

I've got a couple of private messages over the years on building these speakers so I decided to do this thread to compile all the info I have.

Original drivers are Scan Speak 18W/8542-01 for the woofer and SEAS 25TFFC for the tweeter.
When I built mine SEAS 25TFFC was discontinued and SEAS 27TFFC was the replacement but it seems that nowadays you can get the 25TFFC again:

https://www.madisoundspeakerstore.c...s-prestige-25tffc-h0519-textile-dome-tweeter/
https://www.hificollective.co.uk/components/seas-tweeter-25tffc-h0519-06.html
SEAS H0519 25TFFC 2015/6 manufacture Tweeter NEW



BASS Reflex tube
The bass refles tube measures 50mm diameter and 125m lenght.
Beware It's a straight tube, doesn't get a smaller diameter in the end. And that seems a bit dificult to find.

The only proper tube I found is this one:
https://willys-hifi.com/collections/reflex-ports/products/bass-reflex-port-50mm
This tube looks exactly the same as the original, although a litle longer, you just have to cut it down to 125mm.

The tube in the end has some rectangle of MDF (lower thickness than the cabinet) glued in check the photo:

 

[Whoops]

These are some photos of my builds:

 

[Whoops]

There's Bitumex and foam used for damping inside, use this photos as reference:

 

[Whoops]

You will find a different schematic online for the the crossover, the other schematic is wrong, it was drawn with the wrong polarity.
This is the correct schematic, an it's confirmed with an original ProAc speaker

 

[Whoops]

Dimensions
16” (406mm) high 40.6 cm
8” (203mm) wide 20.3 cm
10” (254mm) deep 25.4 cm

Wood is MDF, originals have a type of PVC Cherry Veneer.
I used MDF with a Wood Cherry Veneer, the MDF board already came with the Cherry Veneer glued in.

 

[pucho812]

Any cabinet drawings?

 

[Le Roux]

You do beautiful work on your builds

 

[Whoops]

Finished 2 more, these ones have a centered tweeter

 

[Whoops]

Scan Speak 18W/8542-01 is now discontinued, the replacement is 18W/8542-10,
Seems to be the same but with a surround made of a slighty different material (maybe better) and the Dustcap is a bit more transparent than the 8542-01.
Price for the 8542-10 also increased a lot since the last time I ordered the 8542-01. It's now 50€ more expensive

 

[backfisch123]

is it possible to connect and solder the parts just with the parts itself and glue them on bitumen? if yes I don't get how to connect them. thanks in advance. ( I also just want to normal amp them not bi amp)

 

[Whoops]

In theory you could, but that's a really crappy solution, glue will dry and break over the years, constant vibration inside the cabinet will also lead to connections breaking.

But above all, there's really no need for that when the schematic is so simple that you can easily mount the components on Veroboard, cheap, easy and simple.

You can also Home Etch a PCB,
here is the drawing for home etch, just print it and transfer it to copper



here are photos of the crossover:

 

[metalockpick]

In theory you could, but that's a really crappy solution, glue will dry and bread over the years, constant vibration inside the cabinet will also lead to connections breaking.

But above all, there's really no need for that when the schematic is so simple that you can easily mount the components on Veroboard, cheap, easy and simple.

You can also Home Etch a PCB,
here is the drawing for home etch, just print it and transfer it to copper

View attachment 116153

here are photos of the crossover:

View attachment 116154

View attachment 116155

View attachment 116156

View attachment 116157

 

[metalockpick]

Ambitious project!
Steel laminate inductor for the woofer would take more power before saturation of the core, and an air core inductor with low DCR would be preferred on the tweeter.
Usually, with a three pole HF crossover, you need to wire the tweeter out of phase, but it can vary with different drivers and crossovers and crossover points.

I worked for the US Scan Speak distributor in another lifetime. Good stuff.
A guy made a D'Appolito 717 cabinet out of granite and epoxy, for which I selected and matched drivers. That sounded much better than MDF (which is still a denser, harder material than most).

-Lots of improvement to be had with upgrading cabinets and tweeters.

Experimenting with xrossover values on the HF driver (especially because it's not the original unit) is advised.

 

[Whoops]

Ambitious project!

I’ve built a few of these units,
And it’s not ambitious at all, everything is easy and straight forward.
Once you have the cabinet then it’s pretty easy to mount everything

My cabinets were done using a CNC machine to cut the wood,
But anyone can also do it without a CNC machine, just using a simple router or even a jigsaw.

Experimenting with xrossover values on the HF driver (especially because it's not the original unit) is advised.

No experiments should be done at all,
Just follow exactly the details and information that I posted.
This thread is about a clone of the ProAc Studio 100, so for that just copy it and don’t mess around

 

[metalockpick]

What's ambitious is the sheer number of cabs you are building.

When I had access to all of the flavors of the latest European tweeters, I would find that there were real sonic differences among all of them.

Going with a different tweeter is likely to change the sound/balance of the speaker, which was was originally balanced with the crossover.

See if you can find the spec sheets for the original and new tweeters, and it wouldn't hurt to take an impedance plot of both. Slight value changes can be made to crossover elements to accurately match a different tweeter into the old design.

Because this design wasn't in the least cost-no-object (cabinet, inductors, HF unit), improvements can be made while keeping the general concept .

Steel laminate inductors are lower DCR, so even if you don't wind the speakers up crazy loud, they will tighten the low end.

Large gauge air core inductors for the HF are also advantageous, though a few more $$.

Since you are going through all the effort, I'm making suggestions in hopes you get results superior to the originals. Just my $.02

 

[EarthTone]

This is amazing. Just saw this thread for the first time. I swear by my Proac 100’s for mixing duties with an Adcom gfa-555 that has the Jim Williams mod. That setup rules! Always wanted a pair for upstairs listening to records away from the studio. Maybe now’s the time to DIY … What amp do you like with yours, @Whoops ?

 

[Whoops]

What's ambitious is the sheer number of cabs you are building.

They were built many years ago,
I think in 2012.

The factory with the CNC machine had a minimum number of 12 units, so some friends joined in.
I just have 4, a pair in my mixing room and a pair in my living room.
The other 8 cabinets went to friends

Going with a different tweeter is likely to change the sound/balance of the speaker, which was was originally balanced with the crossover.

Like I said before,
just follow the parts I mentioned.

The Tweeter is the SEAS 25TFFC, and it's available

See if you can find the spec sheets for the original and new tweeters,

Don't do that, just get the correct Tweeter, otherwise you will never have a clone of the Studio 100 speaker, you will have something else.

 

[Whoops]

Always wanted a pair for upstairs listening to records away from the studio.

I completely understand that, that's why I have a pair in my mixing/mastering room, but also use them with my Hi-Fi in my living Room, where I just listen to music.

Maybe now’s the time to DIY …

For Sure,
it's a very rewarding project and easy to do, the cabinet might take some time, but overall it's an easy project

What amp do you like with yours, @Whoops ?

Well, I would love to able to tell you I had a Bryston 3B (that's what I dreamed of) but I never was able to get the cash to buy a Bryston.
In the studio I use an humble Quad 405, modified with the DADA high-end board V3 and Dual Mono PSU, it sounds pretty good and does a good job.
Probably the Bryston would be better, I don't know as I never tried it, maybe one day...

In my living room I just connected them to my existing Hi-Fi that has a Denon UPO-250 power amp,
and sounds perfectly good for music listening

 

[mata_haze]

Any chance at all to do another run of cabinets?

 

[Whoops]

Any chance at all to do another run of cabinets?

Not really, I’ve done it 11 years ago, the CNC place already shut down for good.

Also I only do DIY for fun and for myself, I don’t do it for profit or for money.