A MLTL using an 8" driver will be quite big.
Over here, I put 8" low Vas TB subs in small sealed boxes, controlled by a sub amp, giving me amplification and a XO, and placed either my little 0.4x mini-k, or my Brio clones, and it sounds great. Fast and controlled bass from the sealed subs, going down to about 35Hz using room gain.
If you want more extension, I suggest the XRKi for the 8" woofer, but not for the second one you mentioned.
Over here, I put 8" low Vas TB subs in small sealed boxes, controlled by a sub amp, giving me amplification and a XO, and placed either my little 0.4x mini-k, or my Brio clones, and it sounds great. Fast and controlled bass from the sealed subs, going down to about 35Hz using room gain.
If you want more extension, I suggest the XRKi for the 8" woofer, but not for the second one you mentioned.
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What is the ideal Qts for KaZba? Did you mean stronger motor is needed? I kinda like the KaZba concept, as I have been reading about H frame. I am thinking about building H frame, Z baffle, no K aperture. In this case a high Qts will work, dont they? The 8” driver has Qts of 1.1
Thanks perceval. If going the sealed route, should I just work out a dimension using Vas?
High Qts woofers work best for bass in an OB/dipole situation.
X was just mentioning that an 8" woofer won't give you much bass, as it doesn't move much air compared to a 15", which most people use in OB bass.
I tried my TB as dipole (although they have a lowish Qts) and they didn't have much to offer under 60Hz. Placed them in a sealed box, and now they go to 35Hz with room gain.
For sealed box dimension, get something like WinISD to find the optimal sizing. Other apps are HornResp, and the defunct LeonardAudio software that I like a lot. There's also a bunch of paying apps out there, but the free ones I mentioned are very good.
PS. Any good surfing around your place?
X was just mentioning that an 8" woofer won't give you much bass, as it doesn't move much air compared to a 15", which most people use in OB bass.
I tried my TB as dipole (although they have a lowish Qts) and they didn't have much to offer under 60Hz. Placed them in a sealed box, and now they go to 35Hz with room gain.
For sealed box dimension, get something like WinISD to find the optimal sizing. Other apps are HornResp, and the defunct LeonardAudio software that I like a lot. There's also a bunch of paying apps out there, but the free ones I mentioned are very good.
PS. Any good surfing around your place?
For KaZba, Qts between 0.35 to 0.5 can work, but try at least with 12in drivers. In my experience, a dual 8in just did not cut it. However, your results may vary depending on size of room and your room is very small.
KaZba is different from open baffle dipole in that the K aperture loads the cone so it needs a stronger motor (lower Qts, higher B). If no K aperture, feel free to use high Qts OB drivers - but it is no longer a "K".
Quasi-Kazba
0.6 Qts is not that high... (although they may not measure as advertised). Those 6 inch drivers could work as a quasi-Kazba speaker. If you have a separate subwoofer to handle the deep bass, then you would not need to worry about a lot of displacement.
If you did want to use them for lower frequency bass, then you could use more of them per speaker (i.e, 4 drivers per speaker instead of two; 5 of them would equate to about the area of a single 15 inch driver).
The other issue is what size Kazba box you would need to make. Since the Q is higher than what X was designing, you would need to have a larger box and a larger Karlson-style opening than what a lower Q driver would allow, which would load the driver less.
Since you don't already own the drivers, it might make sense to pick up a pair of larger drivers which would allow you to build the box in the style that X was designing. I would definitely go with the two driver approach, though, reversing the orientation of the two drivers from each other (reducing second order distortion is a good thing).
Retsel
0.6 Qts is not that high... (although they may not measure as advertised). Those 6 inch drivers could work as a quasi-Kazba speaker. If you have a separate subwoofer to handle the deep bass, then you would not need to worry about a lot of displacement.
If you did want to use them for lower frequency bass, then you could use more of them per speaker (i.e, 4 drivers per speaker instead of two; 5 of them would equate to about the area of a single 15 inch driver).
The other issue is what size Kazba box you would need to make. Since the Q is higher than what X was designing, you would need to have a larger box and a larger Karlson-style opening than what a lower Q driver would allow, which would load the driver less.
Since you don't already own the drivers, it might make sense to pick up a pair of larger drivers which would allow you to build the box in the style that X was designing. I would definitely go with the two driver approach, though, reversing the orientation of the two drivers from each other (reducing second order distortion is a good thing).
Retsel
I made a slot loaded open baffle (SLOB) with qnty 6 x 6.5in high Qts polycone woofers once and it sounded very very good. The bass had a nice quality of naturalness and good for not shaking the room walls, but giving you the deep and articulate notes when you sit nearby. Although made of thick cardboard, it was one of the best sounding speakers I had heard. I used a full range to cross-over around 300Hz to 400Hz as a FAST.
Cheap and FAST OB, Literally
Cheap and FAST OB, Literally
Thanks everyone for your input. If I may share my plan regarding this speaker build, it is to fill the lower end to accompany my 0.4x Mini Karlsonator using 1 Vifa TC9 each side. I want this speaker to fill 200Hz and lower. Flat down to 50Hz or so should be enough for me. The 0.4x K is rated 8 Ohm and 88dB/W/m, is that about right? Then either the 6” or 8” driver above can be wired in parallel to get 4 Ohm and 94dB/W/m? I am looking at open Z baffle here.
Does the above sound doable, and will these speakers work just okay? They are bargains, priced much like Factory Buyout drivers.
If I’m running the above setup passively, how many W do I need from my amp?
Thanks so much!! I’m excited now.
Does the above sound doable, and will these speakers work just okay? They are bargains, priced much like Factory Buyout drivers.
If I’m running the above setup passively, how many W do I need from my amp?
Thanks so much!! I’m excited now.
You can wire the mini-K and the woofer in parallel, and get 4 Ohms (that is if you don't use a XO) but you will not get 94dB.
If you use a XO (well, you'll need it, so it's not really a suggestion) then you are back at 8 Ohms.... and still not 94dB.
The best way to handle this is to use a sub amp. It can be bought new, or salvaged from a subwoofer box with a damaged woofer. Plenty of people selling 2nd-hand plate sub amp. Should be able to get it cheap.
With the plate sub amp, you get a variable XO, a boost at about 25-35Hz (most of them have it) and a volume level to match output to the mini-K. That way, you don't need to try to mess with a passive XO.
If you use a XO (well, you'll need it, so it's not really a suggestion) then you are back at 8 Ohms.... and still not 94dB.
The best way to handle this is to use a sub amp. It can be bought new, or salvaged from a subwoofer box with a damaged woofer. Plenty of people selling 2nd-hand plate sub amp. Should be able to get it cheap.
With the plate sub amp, you get a variable XO, a boost at about 25-35Hz (most of them have it) and a volume level to match output to the mini-K. That way, you don't need to try to mess with a passive XO.
Hi perceval, thanks for your input. Sorry I wasnt clear. I mean wire two woofer, together to make 4 Ohm load and then this is connected to the Mini K. I read this thread from page 1 and I believe I read paralleling 2 88dB/W/m can result in 94dB/W/m.
So with this new info, what do you think about my plan above? 50 or 60Hz to 200Hz only. ��
Okay noted on the sub amp. So let the Mini K run full range as it is now?
So with this new info, what do you think about my plan above? 50 or 60Hz to 200Hz only. ��
Okay noted on the sub amp. So let the Mini K run full range as it is now?
Why only be limited to 50-60Hz range?
If you had the space and the will to go with big 15", I'd say sure, go ahead with the dipoles. That's what I have playing right now, and it is quite satisfying.
But, if you still want to stay within a 8" woofer for the low end, stick an 8" sub into a sealed box, power them in parallel (two 8" @ 8 Ohms (one on each side) giving you 4 Ohms for most sub amps out there) and let the 0.4x run free/full range.
That should give you around 35Hz to whatever low end you settle with the mini-K (they can do better than 200Hz) by letting them roll off naturally, which is a lot more satisfying than 50-60Hz while listening to pretty much everything!
If you had the space and the will to go with big 15", I'd say sure, go ahead with the dipoles. That's what I have playing right now, and it is quite satisfying.
But, if you still want to stay within a 8" woofer for the low end, stick an 8" sub into a sealed box, power them in parallel (two 8" @ 8 Ohms (one on each side) giving you 4 Ohms for most sub amps out there) and let the 0.4x run free/full range.
That should give you around 35Hz to whatever low end you settle with the mini-K (they can do better than 200Hz) by letting them roll off naturally, which is a lot more satisfying than 50-60Hz while listening to pretty much everything!
I am not limiting myself, it's just what the spec of the woofers say, their Fs is about 50Hz My room is very small, 230x290cm or 7.5x9.5 feet dorm room. So 15" is not doable in my case. Thank you for your suggestion, I will look into that. What woofer do you use and how much power are you pumping into it?
My room is very small, 230x290cm or 7.5x9.5 feet dorm room. So 15" is not doable in my case. Thank you for your suggestion, I will look into that. What woofer do you use and how much power are you pumping into it?
I was over in Multi-way and saw a speaker Kec made:
Adason has a great recommendation for a dual TC9 and Dayton dome tweeter.
MTM with TC9fd
I think I did an open baffle with a TG9FD and same tweeter. I got the same crazy flat response.
Adason has a great recommendation for a dual TC9 and Dayton dome tweeter.
MTM with TC9fd
I think I did an open baffle with a TG9FD and same tweeter. I got the same crazy flat response.
The Dayton RS225 looks very nice. Unfortunately, the EU price is something like double the US price. I found out recently that I can buy MCM speakers at a fair price from Farnell. Would any of their 8" work in the KaZba? I looked at the "long excursion" model, but maybe another one would be better? My ESS AMT is on order and it seems that a KaZba would work well before I build some kind of Synergy horn with it.
hi Pelanj,
maybe - if can find real measurements within Newark's reviews or other places. Many of MCM's drivers must have bogus spec.
XRK971 - whats a good Qts for Kazba work? - is there much cavity peak with the apertures in place ?
Two which are good =
MCM DVC 12 used in the late W. Marshall Leach Jr.'s sub - sat system
https://www.newark.com/mcm-audio-select/55-1465/woofer-12-dual-voice-coil/dp/34C6021
MCM 8 used by Bill Fiztmaurice for Autotuba and T19
https://www.newark.com/mcm-audio-se...ursion-woofer-120w-rms/dp/88C7835?st=55-24-21
55-1465 12" - had it in a K12 with vent sealed
maybe - if can find real measurements within Newark's reviews or other places. Many of MCM's drivers must have bogus spec.
XRK971 - whats a good Qts for Kazba work? - is there much cavity peak with the apertures in place ?
Two which are good =
MCM DVC 12 used in the late W. Marshall Leach Jr.'s sub - sat system
https://www.newark.com/mcm-audio-select/55-1465/woofer-12-dual-voice-coil/dp/34C6021
MCM 8 used by Bill Fiztmaurice for Autotuba and T19
https://www.newark.com/mcm-audio-se...ursion-woofer-120w-rms/dp/88C7835?st=55-24-21
55-1465 12" - had it in a K12 with vent sealed
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