As far as I understand it the force cancelling part comes from both woofers being solidly bolted to each other inside the cab, there is one woofer on either side of the cab.
Since they are both of the same polarity most vibrations induced by the woofer cone movement are cancelled out.
I think cabinet volume should be the same as for two woofers in one box, which is what these are.
I have not heard Barefoots personally, on the other hand I have never heard a bad word spoken/written about them on the appropriate web fora or in the press.
Whatever Thomas Barefoot is doing seems to be working.
Since they are both of the same polarity most vibrations induced by the woofer cone movement are cancelled out.
I think cabinet volume should be the same as for two woofers in one box, which is what these are.
I have not heard Barefoots personally, on the other hand I have never heard a bad word spoken/written about them on the appropriate web fora or in the press.
Whatever Thomas Barefoot is doing seems to be working.
or u could go all active, but thats where my experience runs out lol. The other halfway house option could be a line level xo, but that would require 2 identical power amps, and gu may be able to use your current amp as pre filter stage. Visaton TIW200XS seems good for 40hz f3 in just over 25 litres, iirc. Fostex or others not specifically Subs, are likely to need more volume.
I was thinking about something simmilar.. two way bookshelf or tower with 10" beyma 10br60v2 on the side and visaton B80 fullrange.. crossed with miniDSP at around 300Hz. You can use small closed box (~25L) and equalize woofer with Linkwitz transform which miniDSP can do.. that would be nice small fullrange system
sumacSK, I hear you 
MiniDSP could do this all?? Without me having to get new amp or otherwise (significantly) change signal path? Sorry to ask stupid questions, I've been reading up on miniDSP, don't quite get it yet. Just how a XO can be placed between dac and amp is beyond me... What is the signal path here and what do I need to make it happen?
What about attennuation for the FR's, can miniDSP do that? Low SPL, 70W amp and 90db sensitivity are bit of a mismatch, I fear.
A real subwoofer would probably be a good idea, WAF-wise. I like Fostex and they make FR's and woofers so I thought it would be a good idea, integration and that. But that cabinet volume did get out of hands
MiniDSP could do this all?? Without me having to get new amp or otherwise (significantly) change signal path? Sorry to ask stupid questions, I've been reading up on miniDSP, don't quite get it yet. Just how a XO can be placed between dac and amp is beyond me... What is the signal path here and what do I need to make it happen?
What about attennuation for the FR's, can miniDSP do that? Low SPL, 70W amp and 90db sensitivity are bit of a mismatch, I fear.
A real subwoofer would probably be a good idea, WAF-wise. I like Fostex and they make FR's and woofers so I thought it would be a good idea, integration and that. But that cabinet volume did get out of hands
You probably will have to get another amp as I understand you have only stereo amp with 4 outputs for two pairs of speakers (both pairs receiving the same signal).. You can get some cheap amp for woofers, so that is no big deal..
What source of signal you use? You can feed analog signal or preferably digital (you will also need miniDIGI for this) signal to your miniDSP. It will perform crosover duties, eq, delay and gain adjustments and output four analog channels which you feed to your two stereo amps.. With miniDSP you can also use its digital volume control. Also you dont have to worry about sensitivity mismatch, with miniDSP you can control the gain of every individual output.. Hope it is more clear now
Your 70W amp will be plenty enough for fullrangers (there are no passive components so no wasted power).
Beyma I mentioned above is quite shallow and will allow for very slim speaker and high WAF (~12cm)
What source of signal you use? You can feed analog signal or preferably digital (you will also need miniDIGI for this) signal to your miniDSP. It will perform crosover duties, eq, delay and gain adjustments and output four analog channels which you feed to your two stereo amps.. With miniDSP you can also use its digital volume control. Also you dont have to worry about sensitivity mismatch, with miniDSP you can control the gain of every individual output.. Hope it is more clear now
Your 70W amp will be plenty enough for fullrangers (there are no passive components so no wasted power).
Beyma I mentioned above is quite shallow and will allow for very slim speaker and high WAF (~12cm)
Much more clear, thank you sumacSK. Stereo amp, yes, I'd need that other one for subs then. A good option, although I'd need more moving parts than I originally hoped for. I think I'll take my amp and dac with me tomorrow, see how they sound with these 8" Fostex fullranges. If it's worth the hassle at all, I mean compared to a pair of tried-and-true two-ways and an EQ. Nothing wrong with easy
But if someone knows if this FR+woofer thing can (relatively easy) be done using passive XO's and components, no extra amps or so, please tell. (Thanks mondogen for your input so far).
But if someone knows if this FR+woofer thing can (relatively easy) be done using passive XO's and components, no extra amps or so, please tell. (Thanks mondogen for your input so far).
Last edited:
of course it can be done passively.. here for example is nice project using visaton b80 and gf200 woofer FAST aus W200+FRS8M - Visaton Diskussionsforum
passive crossover will be rather expensive
passive crossover will be rather expensive
It is neither easy or cheap to try to passively XO low (i usually consider 200 Hz the cutoff, below which i'd go active)
dave
I use this technique whenever feasible. With drivers in phase & pushing in opposite directions the majority of the reactive force from one cone moving is cancelled by the other driver -- removing it from being loaded into the box.
A sketch of a proposed over the top push-push:
A recent example of a 2-piece unit (EL70eN + 2 CSS EL166 -- woofers worked well and in in the midst of getting complementary finish).
Switfy can point you at his thread where he did A7.3 + helper woofer and more examples (and links to daughter threads) can be seen here: http://www.diyaudio.com/forums/full-range/144099-thread-tysen-variations-fast.html
dave
Part of what gives a little speaker its spaciousness is the very small box. It becomes an omnidirectional speaker thru much of its range. You do want to pull it away from the wall, if you can, to get the effect. The skinny tower with the side firing sub it a cool idea, but I've never managed to get a woofer turned 90 degrees to sound right. Never heard one that did, either. Some folks may have better luck with that than me. Dave maybe?
I understand about that cats. Maybe you could add weight to the speaker stands? Kitty litter works very well (really). Or maybe you could build the speakers into scratching posts for the cats. Cover them with carpet and let the cats play. Just be sure to cover the driver with sturdy grills. Just joking - sort of. Actually, I kinda like that idea. Purrrrrrr.......
I understand about that cats. Maybe you could add weight to the speaker stands? Kitty litter works very well
(really). Or maybe you could build the speakers into scratching posts for the cats. Cover them with carpet and let the cats play. Just be sure to cover the driver with sturdy grills. Just joking - sort of. Actually, I kinda like that idea. Purrrrrrr.......
I have managed to make it work fine. The Tysen you liked when you were here have to be placed such that you listen to the woofer at 60 degrees,
dave
Here is the link Dave's referring to. Funny that, when I first read this thread I immediately answered your question to myself: MY speakers!
Honestly, the low spl resolution and bass extention of these loudspeakers is addicting. Having the woofers firing sideways is not a problem if you take a few simple measures when designing the enclosure: Make sure you mount both drivers within a quarter wavelength of the crossover frequency, and make sure the side baffle where the woofer sits in is narrow enough for the woofer to stay in 4pi radiation. Both measures will aid in maintaining the quasi point source nature of the emitted sound waves. In my situation I get excellent results even at a relatively high crossover point of 250hz LR4.
Like Dave, I would highly recommend you to go fully active. I'm using Hypex' excellent AS2.100 units, which consist of two 100w @4ohm class D ucd amps and a DSP board per unit. Not only gives you this the opportunity to very quickly dial in the crossover, extending the bass performance via a Assymetric Shelf, etc, more importantly it allows you to tackle room modes quite effectively: I have a nasty spike @31 hz and @ 60hz in my room. Notching these out made all the difference.
Last edited:
I like the idea, but I myself havent quite witnessed a side firing woofer first hand, but i suppose if its crossed low enough (and it is, i think) then I dont think it would dissuade me. However, I do kinda like the idea of a micripole...lol I mean a small ripole sub to a similar point, maybe 300 hz. with the centred forward output Vent, and twin rear vents, then the bass would be pointing right at ya! Whether side firing would make a difference, well Im undecided. Yes and No if you will, and in my minds eye, as I havent seriously tried yet
I did try all kind of systems Horn ,basreflex, closed, Transmission line. Bandpass.
I experienced wit the bandpass warm low also at low levels, Together with low RMS metalcone mid-low drivers also worked well to have good detail at low level. That speaker performed good from a low level to higher levels.
http://www.diyaudio.com/forums/multi-way/137036-big-bandpass-fatboy.html
I experienced wit the bandpass warm low also at low levels, Together with low RMS metalcone mid-low drivers also worked well to have good detail at low level. That speaker performed good from a low level to higher levels.
http://www.diyaudio.com/forums/multi-way/137036-big-bandpass-fatboy.html
The issue here is that to get most woofers turned 90 degrees to sound right, you probably need smaller woofers, or lower, decently steep crossover points.
I think when you try to do that passively, you run into the issues of high DCR and undesirable frequency response.
So I'd say this sort of design should always be active, at least WRT this particular crossover.
Great stuff, Swifty, thanks for sharing. Love the design, too. Active would be the way to go, then, and with those Hypex AS2's I could skip the extra boxes. Only needs more wiring, not a biggie.
What I am concerned about, is the room-response... My livingroom is not the worst, but the side walls and screen are very limiting. I'm thinking 2x9" sub could be too much, and with potentially difficult 90 degree turn, it just migh go seriously wrong. With, say, DZ5's or Ellam25's I'd have everything pointing forward. BTW, someone mentioned Ellams, which were one of the first designs I considered. Before posting here I emailed mr Gravesen about this, he said it's been a while he heard Ellams and didn't remember if they worked well on low SPL. From what I've gathered here they probably would, though, same drivers as ZD5.
Also, if the xo-point needs to be high, I'm a bit concerned about driver-match. I was thinking I'd use the FR's "as is" and the woofer only to give a little more kick, say, below 100hz. It would seem I've overly simplified things with my "low-pass and attennuator" -plan Good thing I'm not in a hurry, it'll probably be a month or two before I have the time to build these.
And I just found out there's a carpenter here in Finland who makes those 250 liter Altec 604 -cabinets, maybe I'll ask him for an audition.
What I am concerned about, is the room-response... My livingroom is not the worst, but the side walls and screen are very limiting. I'm thinking 2x9" sub could be too much, and with potentially difficult 90 degree turn, it just migh go seriously wrong. With, say, DZ5's or Ellam25's I'd have everything pointing forward. BTW, someone mentioned Ellams, which were one of the first designs I considered. Before posting here I emailed mr Gravesen about this, he said it's been a while he heard Ellams and didn't remember if they worked well on low SPL. From what I've gathered here they probably would, though, same drivers as ZD5.
Also, if the xo-point needs to be high, I'm a bit concerned about driver-match. I was thinking I'd use the FR's "as is" and the woofer only to give a little more kick, say, below 100hz. It would seem I've overly simplified things with my "low-pass and attennuator" -plan
Good thing I'm not in a hurry, it'll probably be a month or two before I have the time to build these.And I just found out there's a carpenter here in Finland who makes those 250 liter Altec 604 -cabinets, maybe I'll ask him for an audition.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.