FAST /WAW subs under MA drivers

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I subscribed to this thread as I'm currently looking for some drivers to add some bottom to my Alpair 7.3s.

One of my objectives is to build a small sized FAST system. I've been looking at various drivers, but is currently set on the TB W6-1139SIF. I've never used these drivers, but I hear good things about them. In a small vented cab with a bit of EQ these little subs should reach an f3 of 30Hz (relatively big and long vent required but doable). From other threads I hear that they play well up to around 600Hz.

The idea is to put the Alpairs in a small sealed cab and cross at something like 250-300Hz using miniDSP.

Comments appreciated.


While a 5.1/etc HT system is not exactly a FAST configuration, it does allow experimentation with different driver / enclosure types at each location. My early trials of dialing in current rig took the opposite approach (i.e. multiple small sealed SDX7 woofers and vented mains and center) . Perhaps the lower XO points employed ( circa 100 or so) are at play, but I found the combination of sealed and ported simply didn't integrate as well as did later all vented enclosures - Alpair7s in the front row, and dual 8" OEM (Eastech) corner located woofers.

My only exposure to integrated FAST systems were the little 2-way Tysen with sealed SDX7 and small highly damped TL with Fostex FF85K, biamped at approx 330Hz - the XO transition was fairly innocuous; and a Lowther/Tone Tubby(?) OB at an audio show. The latter system not only kicked a$$, but would also tear your line of credit a new one.
 
frugal-phile™
Joined 2001
Paid Member
There are as many octaves below 120hz as there are above 120hz. :D

Bill, old age must really be creeping up on you. below 120 Hz is ~ 2.5 octaves... 120 Hz plus 2.5 octaves is response up to 640 Hz.

20-40
40-80
80-160
160-320
320-640
640-1.28 kHz (some rounding usually happens here to make things fit)
1.25-2.5 k
2.5-5k
5-10k
10-20k

My goal with helper woofers is to try to get to 25-30 Hz F3 which is close to Bills 20 Hz F10.

To really get the ommff to do those organs and really dynamic drums, one needs to look at a set of subwoofers <50 hz placed in the room to counter the major resonces (i am sitting on 4 SDX10 to slot in below the 8 SDX7 :D)

dave

dave
 
Perhaps the lower XO points employed ( circa 100 or so) are at play, but I found the combination of sealed and ported simply didn't integrate as well as did later all vented enclosures

So are you suggesting that general speaking sealed goes with sealed and vented with vented, but you shouldn't combine? It never occurred to me that this would be an issue. Considering that there are many ported subs out there, which have been successfully mated with existing setups (sealed or vented), I would think that a combined sealed+vented FAST system wouldn't be a problem as such.

Mind you, I still have little practical experience in the field of speaker building, so I really appreciate all kinds of inputs here :)
 
Bill, old age must really be creeping up on you. below 120 Hz is ~ 2.5 octaves... 120 Hz plus 2.5 octaves is response up to 640 Hz.

20-40
40-80
80-160
160-320
320-640
640-1.28 kHz (some rounding usually happens here to make things fit)
1.25-2.5 k
2.5-5k
5-10k
10-20k

My goal with helper woofers is to try to get to 25-30 Hz F3 which is close to Bills 20 Hz F10.

To really get the ommff to do those organs and really dynamic drums, one needs to look at a set of subwoofers <50 hz placed in the room to counter the major resonces (i am sitting on 4 SDX10 to slot in below the 8 SDX7 :D)

dave

dave

Dave,

Your goal is very much aligned with mine. I prefer sealed box designs that provide a more gradual rolloff but accomplish the same result. It also makes the cabinets a bit more simple to design and implement. When someone has my level of cabinet building skills, a sealed box is about the limit. :(

Below 120hz there's 60, 30, 15, 7.5, 3.75, 1.875, .99, .495.... etc. out to an infinitesimally small number. This results in the same number of octaves below 120 as above. Infinity. :D

I would expect 4 x SDX10 would provide reasonablly deep performance in the right enclosure. The swept area is a little bigger than what I'm currently using for deep bass.

I'm still using a pair of Nick's old Lambda SB12s each in around 4 a cu ft sealed box. Properly placed at the midpoint of the long wall, they go too deep for me to measure (I can only measure to 20hz) and pretty much take care of any deep stuff I can throw at them. But they are positively awful at higher frequencies. Low order crossovers are totally out of the question, fourth order active crossover and bi-amping is needed at a minimum.

Below a certain point, room and speaker placement come heavily into play in terms of how to get deep bass. Though a nice array of large drivers helps, sometimes it only takes a bit of extra room boost to get satisfying results.
 
So are you suggesting that general speaking sealed goes with sealed and vented with vented, but you shouldn't combine? It never occurred to me that this would be an issue. Considering that there are many ported subs out there, which have been successfully mated with existing setups (sealed or vented), I would think that a combined sealed+vented FAST system wouldn't be a problem as such.

Mind you, I still have little practical experience in the field of speaker building, so I really appreciate all kinds of inputs here :)

I have had little success in mixing sealed systems with ported systems. The phase is severely lacking in whack if not completely out of whack.
 
So we have a peerless, SB acoustics, and a tang band. What else? I know the EL166 has proved itself.

Personally I'd use some with a larger Sd than that tang band w6, unless cramped for space. Or two per side. But then value is decreasing. Using the minidsp is the way to go IMO though. I keep saving up for one, then spend it on other junk :eek:

Edit - And what MA drivers are people thing of using for this application? I heard alp7. I think alp6 is an obvious good choice. May need a little higher xo though.
 
Last edited:
I have had little success in mixing sealed systems with ported systems. The phase is severely lacking in whack if not completely out of whack.

Interesting. I hope that I'm not going too much off topic by asking a little more about why or why not to mix sealed and ported systems.

The thing is that the Tangband W6-1139 is the only woofer I've found that is capable of going so low in such a small box, but AFAIK this can only be done in a vented enclosure. Sealed I get about 60Hz f3, perhaps a little lower with a LT, but power handling quickly becomes an issue.

So if I go vented for the woofer then you'd recommend me to go vented for the top as well, even with a XO of say 300Hz? I thought that at this frequency the MA drivers would sound and behave similarly, no matter if they are in a sealed or vented enclosure.


Personally I'd use some with a larger Sd than that tang band w6, unless cramped for space. Or two per side.

Could you elaborate a bit on this please? Why would you want a larger Sd? Two W6-1139s per side is definitely a possibility as the required box size is still very low (I am cramped for space, yes :)). However, in the case of two woofers, how would you design and implement them in a FAST? Sealed or vented? And LT?

I'm interested in hearing other suggestions as well. Thanks.
 
Last edited:
frugal-phile™
Joined 2001
Paid Member
I know there's been some talk of sdx7s in deflectors for fh3 so I assume sealed would work.

Mine stealthWoofers are sealed, after a couple weeks in the system, finally getting to listen to some music... is good.

248075d1320532521-fh3-build-gallery-p10-fh3-fe126en-comp.jpg



One of the reasons i like SDX7 is that it works well in a small sealed box (14-17 litre my preference), and with a touch of boast at 25 Hz, will hit 25 Hz in room.

http://p10hifi.net/planet10/CSS/SDX7-sealed-pass1.pdf

dave
 
Mine stealthWoofers are sealed, after a couple weeks in the system, finally getting to listen to some music... is good.


One of the reasons i like SDX7 is that it works well in a small sealed box (14-17 litre my preference), and with a touch of boast at 25 Hz, will hit 25 Hz in room.

http://homepage.mac.com/planet10/CSS/SDX7-sealed-pass1.pdf

dave

Dave,

What would the box volumes be for a decent solution with EL166 woofers?

-Zia
 
Soren5

The problem with that w6 is it is small with 13mm of travel. I'd personally use something with high Sd and less travel to get the same Vd. They're only 83db efficient and part of what I like in a Fast is you can use the woofer to BSC. So if we use an 85db MA driver, I'd want something that is at least 88db to get me at least 3db BSC.

If you used two of them, you're getting there. Relying on xmax to get you bass isn't something I'd normally practice, unless tight on space as said before. This is basically what Klippel is all about. As the cone moves out, things get non-linear. So a larger woofer traveling less, will inherently stay more linear. I think I've actually seen Klippel data on that w6, but I can't remember if it was good or bad. So there again, using two cuts down on the required travel.*

Higher Sd usually means more efficient, which means less travel. Cause you could say, it doesn't matter if there is an spl mismatch, I'm using a minidsp so I'll just boost the woofer. Ya but then you'll be really using that 13mm of travel and, well, I just don't think it'll sound as good as these incrideble MA drivers ;)
 
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.