Building a FAST / WAW speaker

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi, im about to start with a FAST speaker project and i want to know if this combination of speakers would be a good choice:

FullRange: Dayton Audio RS100-4
Subwoofer:Tang Band W6-1139SIF
Passive Rad: Dayton Audio SD215-PR (Loaded with 25grs)

The xover point would be at 300hz with a 3rd Order Butterworth.
After simulating the system in WinIsd the Response would be approximately from 38hz -3dB to 20khz:)confused:) (dont really know how high the RS100 goes).

The most important thing in this build is size. (the smaller the better)

My questions are these:
1) The RS100 needs a tweeter or it would be ok alone? :confused:
2) What other choices are in this price range? :D

\PD: Please take in consideration that English is not my native language. :eek:
 
Rather than a subwoofer with a low efficiency, maybe try something like Visaton W130S or W170S. Cabinet size may be an issue comparing to the TB subs.

For the FR driver, I'd prefer a 3" or 3.5" over a 4" without comparing specs. But something like the Vifa TC9s or maybe a FaitalPRO 3FE22 or 25?

Ideally, the woofer would be more efficient than than FR driver. To minimise losses or adjustments needed to the signal for baffle step correction. In theory, you could instead choose a 4ohm woofer with an 8ohm FR driver or an 8ohm woofer with a 16ohm FR driver.

J.
 
At the risk of highjacking this thread (it seems very close to being dead...) What would be a good crossover point in a FAST with a pair of W130S's and TC9's? I have some of each and would like to try a FAST setup. On what is the decision on where to cross based? Also, it seems that most FAST setups use a 1st or 2nd order crossover, so I assume a steep roll-off isn't needed? Any inputs? I'm open for a few "learning moments."
Thanks,
Mike
 
Mike, I think the prevalence of simple first order XOs in FASTs designed by members of the "crossovers are inherently evil, but if you must have them, keep them out of the telephone band, and keep the parts count as low as technically possible" school of thought - not naming names, mind you ;) , is perhaps a bit short sighted.

While not actually having burnt my membership card to said fraternity, I've recently gone the process of comparing several approaches to the same goal - 2way crossover for a FAST system- specifaclly the Alpair 12PW/7.3 MTM that has been referenced elsewhere.
We chose a nominal XO turnover of 300-ish - you can calculate exact parts values for the passive components for either 1 or 3 below, but it may be economically impractical to achieve them wire real world, much less "golden-earned audiophile grade" ( GAG) parts :rolleyes: BTDT !

1) 1st order PLLXO / biamped - the lowest parts count /cheapest method if you acknowledge that most of us crazy DIY nutburgers will generally have more than enough amps of different flavours and power levels in our collection

2) DSP active XO/ biamped - in this case via a surround receiver with such functionality- I can't quite determine from the owners manual exactly he order/type of transfer function of those filters . Does the fact that the cost of this component was already amortized in a different system mean it added nothing to the cost of this iteration of the experiment?

3) "old school" passive speaker level XO - certainly not designed by me using any on-line calculators- but in fact via LMS/LEAP, based on gated quasi anechoic ground plane acoustic measurements of drivers in final enclosure, and which if I recall correctly were a hybrid of electrical filter orders? Total parts cost using mid price range Solen grade inductors and caps was well over $200 Cdn pesos

Dammit, get to the point Chris!

For my ears, approach 3 won by a landslide- I mean, not even close friends. Of course, YMMV, and that assessment could be quite different had approach 2 been implemented with the likes of minidsp 2x4HD and Dirac plug-in, but there goes the "frugal" factor in the system calculus.

So exactly what does that prove?

Aside that I suffer from verbal diarrhoea and delusions of adequacy, you tell me.
 
Thanks Chris. I value your opinion. I have the gear to measure, if I want to go with door number 3, and I do. Anything I build will be strictly for fun unless it turns out far better than my lack of experience would lead one to believe.
So.... after giving it some more thought and reading a few more posts about FAST setups, I've given thought to some other pairs of drivers I have on hand: Mark Audio Alpair 7.3's, Dayton RS-180's, Dayton PS-95's, Tectonic Elements TEBM65C20F-8 3-1/2" BMR's, and several different pairs of TangBand 3 and 4 inch drivers. But, I'd kind of like to try the W170 since I haven't heard it in anything. Maybe I'll just stick with it and the TC9's. Hmmmm???????????
So... how does a guy decide on a crossover frequency when considering a FAST setup????
Thanks,
Mike
 
What, there's supposed to be a methodology involved?

After the last couple of years or so worth of stepping outside my comfort zone, I've built and listened to several DIY and commercial systems with XOs ranging from the "DIYA/FR / FAST / KISS", canon to more elaborate approaches, I've found I gravitate more to the 250-320Hz area for 2ways. Haven't yet gone crazier than that.

with my audio systems ;)
 
In general, what I've picked up from more knowledgable types in DIYAUDIO.

Pick a woofer 6dB more sensitive than the full range driver but with the same impedance.
Crossover the drivers at the baffle step frequency or thereabouts. The better sensitivity of the woofer offsets the bass loss from the baffle diffraction losses.
Use "The Edge" baffle loss calculation software to figure out baffle width and step/crossover frequencies.

If you can size the baffle that the crossover is around 300hz or slightly higher, you're probably going in the right direction.

J.
 
Mike, I think the prevalence of simple first order XOs in FASTs designed by members of the "crossovers are inherently evil, but if you must have them, keep them out of the telephone band, and keep the parts count as low as technically possible" school of thought - not naming names, mind you ;) , is perhaps a bit short sighted.

While not actually having burnt my membership card to said fraternity, I've recently gone the process of comparing several approaches to the same goal - 2way crossover for a FAST system- specifaclly the Alpair 12PW/7.3 MTM that has been referenced elsewhere.
We chose a nominal XO turnover of 300-ish - you can calculate exact parts values for the passive components for either 1 or 3 below, but it may be economically impractical to achieve them wire real world, much less "golden-earned audiophile grade" ( GAG) parts :rolleyes: BTDT !

1) 1st order PLLXO / biamped - the lowest parts count /cheapest method if you acknowledge that most of us crazy DIY nutburgers will generally have more than enough amps of different flavours and power levels in our collection

2) DSP active XO/ biamped - in this case via a surround receiver with such functionality- I can't quite determine from the owners manual exactly he order/type of transfer function of those filters . Does the fact that the cost of this component was already amortized in a different system mean it added nothing to the cost of this iteration of the experiment?

3) "old school" passive speaker level XO - certainly not designed by me using any on-line calculators- but in fact via LMS/LEAP, based on gated quasi anechoic ground plane acoustic measurements of drivers in final enclosure, and which if I recall correctly were a hybrid of electrical filter orders? Total parts cost using mid price range Solen grade inductors and caps was well over $200 Cdn pesos

Dammit, get to the point Chris!

For my ears, approach 3 won by a landslide- I mean, not even close friends. Of course, YMMV, and that assessment could be quite different had approach 2 been implemented with the likes of minidsp 2x4HD and Dirac plug-in, but there goes the "frugal" factor in the system calculus.

So exactly what does that prove?

Aside that I suffer from verbal diarrhoea and delusions of adequacy, you tell me.

Been recently discovering fullrange drivers, just built a pair of ported box with audio nirvana's 8" drivers. I like it a lot! I have a sub woofer that mates weel with this but there is this mid bass lacking, perhaps...then I fell on this thread!

I've been having the same idea of adding a woofer to the fullrange like you just describe.

A bit like this ? : Solen Electronique Inc. | STELLA LIGHT

Do you have an concrete example of such a speaker that you have built and/or designed?
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.