diyAudio (
-   Multi-Way (
-   -   Fostex "boiler plate" speakers (

aeronautical 25th May 2012 10:26 PM

Fostex "boiler plate" speakers
Has anyone has any experience with the Fostex "boiler plate" designs they list on their website?

Madisound has a special section for Fostex's enclosures and plans on their site also.

planet10 26th May 2012 12:56 AM

These are in general not well regarded. Some -- like the FE126 10 l BR -- have been called"cruel jokes"

There are some that are OK, but in every instance you'll find better. On a scale of 1-10 i'd give them 1-6.

Note that i haven't vetted the enclosures for the new FF series yet.


aeronautical 26th May 2012 01:55 AM

Thanks Dave, I appreciate your feedback.

That is frustrating though and here's why: I was looking to build a bust the bank, once in a lifetime, over the top system. I saw the following plans on madisound's site, it's also on Fostex's site: The parts alone are over $10,000 for a pair, probably more like $12,000 all in. The look and layout of them reminds me of the JBL k2 s9800's which were $30,000 per pair and by all accounts sound quite nice. I was hoping these would be as good or better. I would think Fostex would know how to employ their drivers superbly, cabinet, crossover, compatibilty, etc. And I would think Madisound would vet these out a little better if they aren't all they should be based on the price of the parts.

Any advice on where I can find plans for to die for pair?




planet10 26th May 2012 03:05 AM

Fostex multiway drivers get little consideration here. Most people are more interested in the FRs.

That particular woofer is over the top, i certainly had lust in my heart when i 1st saw it. I wouldn't waste them in that box.

And with that kind of cah expenditure, they should at least be bi-amped.

Is this your 1st build?


aeronautical 26th May 2012 04:10 AM


No, I was an electrical engineering student and built a whole bunch of stuff in my twenties...two pair of speakers, which I still own and use but mostly electronics which also still works and I still use. I am in my 50's now. Always wanted to get back into it when the kids got grown.

So now I am looking for some projects with great challenge and hopefully great reward.


planet10 26th May 2012 04:19 AM

I'd suggest, and i'm sure many others will concur, you need some prtactise & exploartion before taking on a project with $10k+ drivers.


Pano 26th May 2012 01:55 PM

Yes, and double yes! I would consider that part of the budget, a little practice first.
Rehearsals don't cost as much as the show, but they sure are important. :D

I've built and heard a number of systems like this. You'll be very happy if you get it right. The Fostex drivers are very nice (I have not heard the woofer). Crossover will be key in getting this right.

aeronautical 26th May 2012 03:37 PM

Thanks guys, your feedback is appreciated.

But if you will indulge me a bit longer, may I wax philosophical briefly:

It's all in the recipe...the right ingredients (correct components), of the right quality (quality of componets), in the right proportion (component to component compatibility), prepared correctly (crossovers, boxes, etc.) is how magic is made. Once in a while back in the 70's a speaker company would get it right and produce a noteworthy (pardon the pun) product. I think it was largely luck, or maybe rather it was skill and a lot of trial and error. When it was right, it was magic. I believe that speaker companies are far more precise these days and make good products without as much trial and error. Also, components seem to be much better to begin with, so that "magic" of a great speaker is easier to attain.

The reason I mention this is because of my pardigm above I want to build a great set without as much trial and error...forgive me if this sounds heretical. I suppose I am wanting to benefit from the knowlege that is out there already and perhaps refine what I start with but I need a starting place well beyond Radio Shack. I have built some fine speakers but that was 30 years ago. The fact that I still listen to them should say something. I have only had to replace some of the drivers as the surround would rot away.

Anyway, I am a good cook (I have the tools and the electrical and woodworking skils), but I need a good recipe.

So I am struggling with how to approach this thing. I was thinking that the Fostex plan I cited would be more or less foolproof but I trust the experience of guys like in this forum so now I am pretty much back to square one. I wasn't a big fan of using horns anyway but some designs get away with it in spades. One thing I did notice, the box looks flimsy to my eyes for such a powerful woofer. Looks to me like it would "breathe" if you follow.

ANY input would be greatly appreciated.

Pano 26th May 2012 04:42 PM

You're welcome!
All I can offer is my experience and opinions - so here goes.

I think the Fostex plans you posted are very much a step in the right direction. It's the type of speaker I like best. I do wonder about the bass box - 150 liters may not be enough, and the crossover. The crossover can make or break a speaker. The drivers themselves will be just fine, tho I might choose another horn. For the price of the Fostex horn, you could do better (IMO)

The system you posted in firmly in the Franco-Japanese school of audio made popular by my mentor, Mr. Jean Hiraga. A school of Hi-Fi inspired by the Americans Altec, Western Electric, JBL, EV, etc. A refinement of those, if you will. I got my start there in the 1980s.

Given the same drivers, I'd go with an 360L Onken bass box, if you have the room for it.
Photo from Ispra.Net - Alex Patak Audio
A new GPA 416-8C woofer could also do nicely there. The mid horn is up for grabs, so many different ways to approach that. Even the Fostex 400Hz horn, that sells for $1000 less (each).

Many people complain about horn coloration, horn shout, horn honk, in-your-face horns, etc. Yep, they can do all that. But they can also disappear and leave just the music. Some of that is the horn, some the driver, but mostly the crossover. Most crossovers just aren't done right, at least not "right" in the sense of Hi-Fi. If you are building a true top notch system, you owe it to yourself to get the crossover right. It needs to be tuned to your drivers, boxes, horns, room and electronics.

Starting out with the published Fostex crossover won't hurt too much, and you may love it. Tho I'd hesitate to pull the trigger right way on the Autoformer attenuators at $250 each. As published, that crossover should cost you under $100 per side with good (non boutique) parts, you can go from there.

You'll get a lot of opinions on what's best and what's not. I've been around this style of speaker for decades and have built a few. You can take my opinion on it FWIW. ;)

planet10 26th May 2012 05:41 PM

What Pano said. You have the ingredients (althou i'd check out other mid horns)... i'd do my own cut of an Onken box (and with 2 woofers per side consider push-push).

XOs are evil and getting them right is far and away the hardest part -- my experience with Fostex recommended stuff such that i'd likely not even consider theirs as a 1st pass. And with all the $$$ involved they deserve to be tri-amped. Say UcD or nCore on the bottom, and built for the purpose tube amps for the top.


All times are GMT. The time now is 08:11 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 18.75%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2018 DragonByte Technologies Ltd.
Copyright ©1999-2018 diyAudio