(sb1000z) Dual 18" Long-throw High Power Subwoofer Speaker Box - Buy Subwoofer,Subwoofer Box,Subwoofer Speaker Product on Alibaba.com
Also is this set up considered Vented?? It kinda looks like it is because each woofer is in it's own enclosure with a port for each, but somehow share the same triangular opening to project the front wave??
Not sure how to build for dual 10's ; I can only find measurements for 15's & 18's.
The Thiele small for the 10's (FS:41.1 / Qes 0.32 / Qts 0.31 / Qms 9.94 / Xmax 5.5 / Vas 1.72 cu/ft / 250w Rms / 500w Peak / 91.7db 1w/1m )
Any suggestions on enclosure would help a bunch.
Thanks
DJ Chino
Also is this set up considered Vented?? It kinda looks like it is because each woofer is in it's own enclosure with a port for each, but somehow share the same triangular opening to project the front wave??
Not sure how to build for dual 10's ; I can only find measurements for 15's & 18's.
The Thiele small for the 10's (FS:41.1 / Qes 0.32 / Qts 0.31 / Qms 9.94 / Xmax 5.5 / Vas 1.72 cu/ft / 250w Rms / 500w Peak / 91.7db 1w/1m )
Any suggestions on enclosure would help a bunch.
Thanks
DJ Chino
That is just a vented design and the shape of the baffle really does nothing but make it possible to pack more drivers into a smaller surface area.. which is beneficial for live sound events. Sound wavelengths at subwoofer frequencies are very long so as long as the drivers are within several feet of each other they couple and act as a single unit. To design something similar for 10" subs just create a model with a program like WinISD and then build a box the shape you want with the internal volume and port dimensions described by the model.
Last edited:
Copy of EAW SB1000? http://eaw.com/docs/2_Legacy_Products/Loudspeakers/SB/SB1000zi/SB1000z_datasheet.pdf
I don't think it can be called simple reflex design. There is something like a reflex port in the horn. Don't know what the small ports in front make
I don't think it can be called simple reflex design. There is something like a reflex port in the horn. Don't know what the small ports in front make
An externally hosted image should be here but it was not working when we last tested it.
WinISD is good & should help you in your design 🙂
They make it a Reflex box ! They tune each driver in their seperate spaces to fb.
They make it a Reflex box ! They tune each driver in their seperate spaces to fb.
Not convinced - the pink stuff that looks like wadding deep inside the horn suggests to me that something else is going on.
The ducted ports and the larger central port together form an aggregate tuning. At high drive levels, the smaller upper ducted ports become turbulent, and assist in exchanging the rising heat from the driver's rear vent and magnet structure to the outside air, keeping voice coil temperature lower, reducing thermal compression due to rising temperature increasing voice coil resistance, which reduces available amplifier power.
The large central port does is not turbulent at high drive levels, so does not suffer from "port compression", and the "V" loading is an acoustic bandpass which increases upper passband output, while reducing high order distortion components.
Cool.
Art
@ chris661
Yeah i didn't see the pink stuff at first, as i only viewed the Alibaba link. Good catch 🙂
@ weltersys
Apart from the front ports, if both drivers are also vented from the rear slot into the V chamber, doesn't that then make a "kind of" tapped horn, if you see what i mean ?
Also, as well as this V design, i've seen many others using the V approach without the slot tuning. But in both cases the V chamber must act like a horn, with not only LP characteristcs, but HP too ? And leaving aside the tuning, as the chamber/horn is a small size, wouldn't the HP f's be up in the hundreds ? Maybe the tuning makes up for the HP ?
Anyway, 99dBW doesn't seem much for 2 x 18" 1kW drivers, in a "supposed" special etc design ! I'm not saying it's crap, just wondering.
Yeah i didn't see the pink stuff at first, as i only viewed the Alibaba link. Good catch 🙂
@ weltersys
Apart from the front ports, if both drivers are also vented from the rear slot into the V chamber, doesn't that then make a "kind of" tapped horn, if you see what i mean ?
Also, as well as this V design, i've seen many others using the V approach without the slot tuning. But in both cases the V chamber must act like a horn, with not only LP characteristcs, but HP too ? And leaving aside the tuning, as the chamber/horn is a small size, wouldn't the HP f's be up in the hundreds ? Maybe the tuning makes up for the HP ?
Anyway, 99dBW doesn't seem much for 2 x 18" 1kW drivers, in a "supposed" special etc design ! I'm not saying it's crap, just wondering.
1)No, the drivers use a large chamber which is slot ported, a TH uses no chamber.
EAW writes "the unique driver mounting of the SB1001 maximizes cone area and allows for the integration of an extremely low turbulence port while minimizing front area".
2) The "horn" is rather small, peaking at 200 Hz, and yes, the HP starts above that.
3) 95-96 dB is the full space sensitivity, half space sensitivity is around +6 dB more. The SB 1000z has similar sensitivity to the DSL TH-118-4 (rated 108 dB 2.83 volts, 105 dB 1 watt one meter), slightly more sensitive below 35 Hz, slightly less above as can be seen in this test:
TH118vsSB1000z
The top ports were eliminated in the higher power handling SB1001 (1200 watts AES rather than 1000 watts AES per driver), slightly lowering Fb.
Art
Attachments
Last edited:
Did you mean LP ?
Thanx for the TH118vsSB1000z link & the SB1001 v SB1000z screenie The later version is clearly better, but both suffer without processing, which looks like + 10dB @ 40Hz ! This must affect their power handling, compared to other designs, i would have thought. I can see that the previous version is tuned lower, with respect to it's T/S parameters and/or box size, than the later version.
I would have thought they would have kept the top ports in the later version, as they extolled the "extremely low turbulence" value of them in the previous version ?
EDIT
I meant to say,
I can see that the later version SB1001 is tuned lower, with respect to it's T/S parameters and/or box size, than the later version.
Regards
I meant to say,
I can see that the later version SB1001 is tuned lower, with respect to it's T/S parameters and/or box size, than the later version.
Regards
1) Yes, the lows pass, the highs above around 200 Hz are cut by the "V" loading plenum.
2) "Suffer" is relative, as you can see the SB1000z has more bottom and less top than the DSL TH-118. The previous version has the extra top front ports, which make the box tune higher than the later version without, EAW may have left the rest of the enclosure the same.
3) The low turbulence port is the large center port. Later driver designs are better at getting rid of voice coil heat, so do not require the small ports which become turbulent air exchangers at high level, and were eliminated.
Thank you guys for all your input
sebDIY & Chris661, I agree that thare is somekind of slot port which I did not notice in the Alibaba pic but did see it in The EAW shot.
Weltersys, thanks for all your technical knowledge it helped alot.
At this point I probably will look into another design more feasable for my two 10's I wanna use a box that would be efficient with a tuning freq around 36.5hz to about 38.0hz.
another question that I have is how do I design a HP filter to tune out those terrible low freqs. below 30hz I do not wanna damage the woofers???
Thanks again
sebDIY & Chris661, I agree that thare is somekind of slot port which I did not notice in the Alibaba pic but did see it in The EAW shot.
Weltersys, thanks for all your technical knowledge it helped alot.
At this point I probably will look into another design more feasable for my two 10's I wanna use a box that would be efficient with a tuning freq around 36.5hz to about 38.0hz.
another question that I have is how do I design a HP filter to tune out those terrible low freqs. below 30hz I do not wanna damage the woofers???
Thanks again
I just modeled a slot loaded band pass sub similar to the EAW (without small vents) here: http://www.diyaudio.com/forums/subwoofers/119854-hornresp-444.html#post3919028
This design actually goes to about 31 Hz (-3dB) and is 100dB efficient at 2.83V and maxes out at 124dB.
This design actually goes to about 31 Hz (-3dB) and is 100dB efficient at 2.83V and maxes out at 124dB.
Analog crossovers with HP filters are available used for less than the cost of parts to build one. Many equalizers also have HP built in. Most sub /top alignments benefit from time aligning the tops to the subs, which requires the tops be delayed, in which case DSP (digital signal processing) is needed. DSP pricing has come down in price, even new, stereo two way in the $100 range are available, and many amplifiers now have DSP built in.
Weltersys: Yes my amp is a crown XLS1500 and it does have a built in HP filter but when I contacted Crown to find out what was the HP freq they said it was 50hz when the HP filter is engaged and it drops fast below 50hz according to the tech.
I think 50hz is a bit too high??? I wanna cut it off between 30 to 25hz
I think 50hz is a bit too high??? I wanna cut it off between 30 to 25hz
Considering your woofers FS is 41.1, you would not want to tune the cabinet's Fb much below that (unless going with a tapped horn) and the difference between 40 and 50 Hz is only 1/3 octave. You can get a lot more "bang for the buck" tuning higher than lower- a lower tuning will have your speakers run out of excursion where most of the "kick" occurs in most music.
If you are serious about the octave between 25 Hz and 50 Hz, you will need to consider purchasing speakers capable of serious output down there, and then will need DSP (or an amp with DSP) to provide the lower HP.
As it is, I'd suggest regular ported boxes tuned around 45 Hz for your speakers- the SB1000 type design really won't give you much advantage, and would require prototyping to get the tuning right for the TS parameters of your drivers.
Art
- Status
- Not open for further replies.