Fostex "boiler plate" speakers

[Pano]

Depends. Some folks like line arrays, others don't.

In the case of Gary's system the four 15s are not in a box so bass loss is high, similar to open baffle. The 8" mid has no trouble keeping up at all, even with lower power. The system is active, so it's easy to adjust.

[aeronautical]

McIntosh has sure fallen in love with line arrays

I'm going to contact the folks at ae for box specs...I will let you know what I find out

[Pano]

Yes, I've heard them. They sound really big and impressive. Bigger than life. That's what I didn't like about them. Fun, tho. Well done in the genre.

Looking forward to what you find out about the AE 15s.

[aeronautical]

I am almost back to square one but I have made some quality decisions based on feedback from this forum. An active crossover is a definite so I guess three stereo amps are in the cards. I have some questions that I am hoping you guys can help me with. I have decided on a three way tower. I want accurate fine detail but I also want somwething can fill a large room when cranked and remain composed. My dilemma's are back to which drivers, how big, and how many. I thought I would fire off some questions and see if I can get some consensus from the collective wisdon of you sages. My quest so far has caused these questions to emerge:

Just an observation, but it seems that the trend among the most respected speaker manufacturers ( excluding the exotics ) is toward smaller but multiple drivers, especially in the bass region. Something like three 8" woofers as opposed to a single 12" or 15".

Is there a sonic reason for this or does it have more to do with the economics of building and selling speakers commercially...eg size, shipping costs, asthetics, etc?

Would two 12's be better that one 15" for a vented box? Is there any kind of "best practices" here?

Seas and Accuton seem to enjoy excellent reputations. I started out looking at doing one of Fostex's published designs but haven't received a lot of positives about the design as written. I have been trying to get data on Acoustic Elegance without much luck.

If you were trying to build your best ever set of loudspeakers what bass driver(s) would you go with?

What midrange and tweeter would you go with?

I was originally going to use a horn midrange per the Fostex plan but again, looking at what is being build, sold, and reviewed, at least reviewed well, is tending to point me to a more conventional approach. I see alot of MTM designs in their own separate enclosure or separate compartment of the one main box.

How do you select the best configuration for this?

Is there a good way to select drivers that are appropriate for each other so that the whole system is balanced well?

Would staying with the same "family" of drivers be wise...Accuton ceramic, Seas, etc.?

I have looked at plans till my eyes glaze over and haven't been able to gleen if there any "best" designs out there for a three way tower so any help would be appreciated.

Thanks

Mike

[Pano]

Good questions Mike, here is my 2 cents, FWIW:

Budget for measurement equipment. A calibrated mic, a sound card with phantom power (M-Audio works well). Some software like ARTA, HOMImpulse and the crossover designer worksheets. Most of that is free. I also use a cardioid mic for indoor measurements as I find it "hears the room" much more the way my ears do than an omni.*

Originally Posted by aeronautical

Is there a sonic reason for this or does it have more to do with the economics of building and selling speakers commercially...eg size, shipping costs, asthetics, etc?

Most will tell you it's engineering, but it's mainly fashion and aesthetics. Towers are in fashion at the moment.

If you were trying to build your best ever set of loudspeakers what bass driver(s) would you go with?

Altec/GPA 416 or 515 is my first choice, but I have several friends who use the AE drivers and love them. I've heard them, they are very good.

What midrange and tweeter would you go with?

Horns for me, of course! But I've heard the Eminence Beta 8A and Beta 12LTA used as midrange on open back or open baffle rigs and they were amazing. Very clean, pure midrange - almost electrostatic sounding. The 8" is much easier to crossover to a tweeter than the 12". It mates well with the Hi-Vi planar tweeters.

How do you select the best configuration for this?

I'd use the midrange open back, either cardioid or open baffle. Woofers in a separate box.

Is there a good way to select drivers that are appropriate for each other so that the whole system is balanced well?

Staying within a family line is not a bad idea if you don't have a lot of experience with the drivers in question. One thing that rarely gets talked about (here) in speaker design is harmonics. All drivers have them, not all harmonic structures fit together well. You don't want to be fighting that.

I have looked at plans till my eyes glaze over and haven't been able to gleen if there any "best" designs out there for a three way tower so any help would be appreciated.

There aren't any. Go to any big audio show and you'll hear that fast. So many speakers, so many sounds. Often similar looking designs sound quite different.

I hope that helps.


*I use the humble AT-2020 (calibrated) for this and find it works great.

[aeronautical]

Thanks Michael,

It helps a lot.

Ok, if I go with a horn for the mids who would you use. I will probably do 2 15's like you mentioned once before. Not trying to put you on the spot...just need direction. The reason I will probably go horn is I think there is a whole bunch of complexities with open baffle type stuff...well beyond my abilities. Besides...and don't laugh...I may do another project in the future after these that looks a lot like the snell's biggest illusions...I just like that look but am not ready for that yet.

This though seems pretty straightforward to me. I will need to build a box and would rather orient the woofers on top of each other.

[Pano]

You're welcome!
Horns are not easy, but if you're up for a challenge... I think I posted a like to some very good horns from Poland earlier in the thread. In the Group Buy section.

Don't discount the the simple and inexpensive Eminence pro drivers. Used in the right way, they are stunning. Super clean, as loud as you'd want and they just sound "right". Open back is easier for the midrange than horns. The nice thing about an 8" cone mid is that there are so many around, new and old. Start with one, live with it a bit, then play driver rolling to your heart's content.

[talaerts]

The fostex ingredients have likely quite some potential. You could start with the fostex filter but it s probably too simple to really shine.
If you go triamp / dsp / active filter, as indicated, then you have more options to get it right over time. Fun !

Considering ingredients, I would consider the Beyma TPL 150 air motion tweeter. Probably better than the Fostex, in fact likely one of the very best high efficiency tweeters on the market. There are a few designs with it, check it out.

For the midrange horn, and compression driver, it is worth spending time looking over manufacturer specs and searching for reactions. B&C has a good reputation, for example.

The fostex woofer is very cool indeed. I don.t know whether it is worth its price however.

[turbodawg]

Originally Posted by aeronautical

I am almost back to square one but I have made some quality decisions based on feedback from this forum. An active crossover is a definite so I guess three stereo amps are in the cards. I have some questions that I am hoping you guys can help me with. I have decided on a three way tower. I want accurate fine detail but I also want somwething can fill a large room when cranked and remain composed. My dilemma's are back to which drivers, how big, and how many. I thought I would fire off some questions and see if I can get some consensus from the collective wisdon of you sages. My quest so far has caused these questions to emerge:

Just an observation, but it seems that the trend among the most respected speaker manufacturers ( excluding the exotics ) is toward smaller but multiple drivers, especially in the bass region. Something like three 8" woofers as opposed to a single 12" or 15".

Is there a sonic reason for this or does it have more to do with the economics of building and selling speakers commercially...eg size, shipping costs, asthetics, etc?

Would two 12's be better that one 15" for a vented box? Is there any kind of "best practices" here?

Seas and Accuton seem to enjoy excellent reputations. I started out looking at doing one of Fostex's published designs but haven't received a lot of positives about the design as written. I have been trying to get data on Acoustic Elegance without much luck.

If you were trying to build your best ever set of loudspeakers what bass driver(s) would you go with?

What midrange and tweeter would you go with?

I was originally going to use a horn midrange per the Fostex plan but again, looking at what is being build, sold, and reviewed, at least reviewed well, is tending to point me to a more conventional approach. I see alot of MTM designs in their own separate enclosure or separate compartment of the one main box.

How do you select the best configuration for this?

Is there a good way to select drivers that are appropriate for each other so that the whole system is balanced well?

Would staying with the same "family" of drivers be wise...Accuton ceramic, Seas, etc.?

I have looked at plans till my eyes glaze over and haven't been able to gleen if there any "best" designs out there for a three way tower so any help would be appreciated.

Thanks

Mike

How about a wmtmw plus subs, low-Q heavily damped enclosures, transient correct?

[aeronautical]

Thanks, but I would need a translation as that blew right by me.


I am trying to get back into the hobby after a 30 year hiatus. We had horse drawn amplifiers and steam powered drivers when I was last involved.

So, could I persuade you into spoon feeding me just a little.

I saw this on our forum here...it looks like where I was headed originally. My new friend Pano like horns like this.

Check out these new horns - Very Impressive