FAST FATT EnABL2'd Active Spawn budget behemoth... maybe... help?

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Hi All,

I've been reading diyaudio, a lot of diyaudio, I feel like my head is about to explode from all the information.

A little while ago I was given a few drivers to play around with, and got bitten by the speaker building bug pretty bad, went out and bought MJK's mathcad sheets and went to town building a TMM MLTL.

It was a pretty ok first effort, but now I want more, a lot more. I love the look of big horns, and would love to have a go at building a pair. The wife also doesn't mind how big I build it, so bonus.

First, my room, it's a big room, 6.5m*10m with 2.5m ceiling. The short sides are both mostly glass, one of the long sides is concrete, and the other side is just a normal wall. There is a small bar down one end that doesn't take up much room, and along the wall with the concrete is mostly covered by bookshelves. I have free range to move things around to fit them in. However, they can't be OB, because I have children, and I don't want them poking around the back of the baffle.

Budget, I live in Aus, the "bank" has given me 400-600AUD (275-415USD) probably after the tax rebate in July to spend on the drivers, the rest is whatever it is.

I listen to a large range of things, a lot of my music is high quality digitized vinyl of mint condition and first pressings, the rest is all lossless CD rips. A short list of what I'm currently enjoying in no particular order.

David Bowie
ELP
Pink Floyd
Led Zeppelin (Mastered by Barry Diament of course)
King Crimson
Flaming Lips
Queensryche (Early)
Avantasia
Dream Theater
Disturbed
Loreena McKennitt
Red Hot Chili Peppers
Rachmaninoff
The Cat Empire

As you can see, there is a range of things from classic rock/prog rock, to metal/prog metal, vocalists, ska, funk, and ideally want a system with a good punch to it.

I've read that a FAST system with a FR could give me what I want (Esp. if I use an active crossover, to help with the varied styles I listen to), FATT is me antagonizing Scottmoose (I love your work, you've done some amazing things) Fullrange Assisted Tweeter Technology :p

What I'm currently stuck on is actually figuring out what drivers, and what enclosure to pop them in. I would love to go all out with a Kirishima and some Sigma drivers, but I don't have the budget for that :(

I'm open to any suggestions, I'm pretty new to this, but am keen as a bean to learn, so please excuse any ignorance on my part.
 
Founder of XSA-Labs
Joined 2012
Paid Member
Here is a pretty good sounding FAST that uses miniDSP:

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

You can save some money by starting with a TG9FD10-8 rather than a $100 10F and sound is about 90% there.

This is my main everyday listening system and plays most music quite well. It does not have high SPL's though.

For that I use the FAST in the Trynergy horn.

http://www.diyaudio.com/forums/full...ing-trynergy-full-range-tractrix-synergy.html

FAST with a high sensitivity full range driver that can handle a lot of power coupled with a slot loaded open baffle woofer can also sound excellent. Here is an example of that with a 95dB PRV 5MR450NDY and 6 x 6.5in woofers in a SLOB:

http://www.diyaudio.com/forums/full-range/259293-prv-5mr450-ndy-fast-applications.html
 
Hmmm, those are nice suggestions, but a little part of me has a burning desire to build something obscenely big.

Scott's Kirishima uses FE206EN's, which I can buy in my budget. Is it possible to modify the cabinet for FAST, is it just a matter of mounting the woofer(s) on the side of the speaker chamber? If so, they could be purchased later when budget permits? And finally, what woofers would be suitable.
 
CA - unless you really want to experience the learning curve associated with implementing the admittedly excellent information on Rod's page, I'd endorse ewollowe's recommendation for the minidsp - or more precisely, the nanoDSP version which uses outboard DACs - allowing yet another upgrade path ;)


How much of a "behemoth" of a FAST system were you contemplating? I recently finally refinished a pair of bi-amped MTMs using Alpair drivers that work quite well. They are approx 48" tall x 18" wide x 10.5" deep.

Shown below with a pair of FH -lites for size comparison.


The format would easily be adaptable to a fair range of drivers of your favorite flavor; indeed this was my second pair of similar design - the earlier build used FF85K, the current successor to which would be on my short list for consideration for such a project.
 

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frugal-phile™
Joined 2001
Paid Member
Would any of the Olson-Nagaoka enclosures be suitable for a FAST? Or the BVR's?

In a FAST with XO 150-400 Hz, you are not trying to extend the bass response, so you have to look at the cabinet for it with a different eye.

We typically use a dedicated aperiodic high taper ratio TL for the midTweeter. Our favorite drivers (so far, many to play with) are Alpair 7.3 & FF85wk (with all the tweaks).

What amps are you going to use? At the moment, looks like the analog sections of a miniDSP could be a weak point in the chain (the digital bit is higely versatile, but limited to 16/48?)… your budget just suggest seeing if you can get away with a PLLXO, really cheap, and if the speaker can be made to suit their limitations, nothing more transparent (2 small Cs+ 1 ¼w R per side for the simpliest one).

dave
 
brain fart on the exact model name - this was the one I was thinking of - I believe several members here can attest to its efficacy
https://www.minidsp.com/products/minidsp-in-a-box/nanodigi-2x8-b

I have that nanoDIGI miniDSP, no complaints. In my opinion it's needing a DAC for each pair of speaker drivers that makes it expensive, i.e. A DAC for a pair of tweeters, and another DAC for a pair of midrange drivers and so on.

Although it does leave an upgrade path, yet I'm still shocked at the sound quality of the $40 Chinese DAC boards that I got. BTW, if I recall correctly, nanoDIGI output is 24b/96k PCM. (because that's what the plug-in runs)

See my 6 Channel DAC I built with balanced XLR analogue output: http://www.diyaudio.com/forums/digital-line-level/283319-dac-preamp.html#post4535959. It's FATT!

Regards,
 
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In a FAST with XO 150-400 Hz, you are not trying to extend the bass response, so you have to look at the cabinet for it with a different eye.
Hmmm, I see your point, I was so caught up in the idea of a horn that I forgot the purpose of them vs. what my intended application is.

I see you've posted up plans of a Tysen V2, with the FF85WK and a pair of SF W14's, the whole kit comes in nicely for my drivers budget, I'm seriously considering going with that design :)

I did have a question though, given the room I'm looking at is 65m^2 will they give me a good volume, and how much "slam" can they provide?

As for the electronics, I will admit to a fair amount of ignorance with regards to amplifiers, DAC's, DSP's, WTF's ETC. :p When I first got bit by the bug 6 months ago I didn't even know what a crossover was, since then I've designed and built a MLTL TMM with passive crossover (Using MJK and Rod Elliot's info), and am learning more every day.

I am in the process of building myself a modular analogue synthesizer from scratch, and have the capabilities to produce PCB's (Through hole and SMD), so I'm not daunted by the idea of making my own amp's and assorted peripherals, and will enjoy learning what's needed. I don't currently own any amp worth anything much at all, as all my speakers are "Computer" speakers.

Regards,
Andrew.
 
as there is as of yet no accepted industry standard for the measurement (conditions) of "slam" - or for that matter several other more traditional T/S parameters :D that question is hard to answer

how long is a piece of string?

65m^2 is definitely not a tiny room, and you might likely need more than even a quad of 6" woofers and pair of direct radiating 4" FR to deliver your full measure of an uncertain parameter
 
I don't have the gear, nor frankly the interest to take in-room measurements, but the Alpair MTM shown in post 9 above certainly do dig deep enough to rattle some loose plastic diffuser panels in an overhead lighting box. Maybe I should get that fixed - nah, it's actually a sort of benchmark - the only other system to do that was a Tannoy Gold 12" :rolleyes:
 
Real slam, the ability of the air to flutter your pants legs. That requires cone area. Any system that wants to really do that needs multiple subwoofers.

This ML-TL will go fairly low. Est F10 below 30 Hz.

dave

What's the estimated SPL of the system, and how much power can the drivers take? It's just math after that to work out if I can get enough volume out of them for the room. An est. F10 of below 30hz is great, I guess I'm not after depress your chest cavity bass, I just don't want something insipid, there has to be a reason to go with the two-way alignment on the bass end, otherwise I may as well go for a single driver full way in a BMC (Big Mother... Cabinet)

I don't have the gear, nor frankly the interest to take in-room measurements, but the Alpair MTM shown in post 9 above certainly do dig deep enough to rattle some loose plastic diffuser panels in an overhead lighting box. Maybe I should get that fixed - nah, it's actually a sort of benchmark - the only other system to do that was a Tannoy Gold 12" :rolleyes:

What drivers did you use? And do you have any details on the enclosure?
 
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Andrew, the system components were Alpair 7.3 as mid-tweeter, and 2 x Alpair12PW (woofer version) in a shoehorn tight fit MTM.

I'm not sure if Dave has released the drawing publically, but it's probably no surprise to those familiar with his work that it consists of a small triangular, rear vented TL for the A7, which is surrounded by a slot ported MLTL for the dual woofers. He might care to elaborate more precisely on the details of the enclosure.

They are currently running actively bi-amped, via an Onkyo 7.1 receiver, and supplemented as much as they need it, with a pair of corner mounted dual 7" woofer "subs". Even by themselves in "direct, stereo" mode, a quad of 12PW in a 340ft^2 basement room deliver enough slam for me - but then, I'm an old fart, and don't listen particularly loud, even to movies.
 
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