Hi .
Got couple of these from some importer . These are unbranded, unmarked, !0 inch woofers , with 2.5 inch voice coil , 1 inch big surround , i expect Xmax to be around 10 mm at lease magnet is 2 cm high with a bucking magnet is suppose.The surround is good quality rubber the type of JL audio with i inch thichness its unusual for its size.
I measure FS=35 Hz.Unable to measure Qtc by -3db method always gave error.
Currently in a sample box of 1.0 Cu feet tuned to 33 Hz and active LPF of 80 HZ
Sounds good but a little bit boomy. My plan is to use them in 1.8 cu feet volume enclosure for one woofer tuned to 35 Hz for Music and HT may be then it would smooth the boominess .
At around 150 Watts it gives some audible noise , since its dirt cheap around 15 dollars a piece, Any suggetion of using them in pull push vented arrangement to get better linearlity. BTW i intend to use 8 of them in 4 boxes.
Got couple of these from some importer . These are unbranded, unmarked, !0 inch woofers , with 2.5 inch voice coil , 1 inch big surround , i expect Xmax to be around 10 mm at lease magnet is 2 cm high with a bucking magnet is suppose.The surround is good quality rubber the type of JL audio with i inch thichness its unusual for its size.
I measure FS=35 Hz.Unable to measure Qtc by -3db method always gave error.
Currently in a sample box of 1.0 Cu feet tuned to 33 Hz and active LPF of 80 HZ
Sounds good but a little bit boomy. My plan is to use them in 1.8 cu feet volume enclosure for one woofer tuned to 35 Hz for Music and HT may be then it would smooth the boominess .
At around 150 Watts it gives some audible noise , since its dirt cheap around 15 dollars a piece, Any suggetion of using them in pull push vented arrangement to get better linearlity. BTW i intend to use 8 of them in 4 boxes.
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Wow look at the size of that rolled surround . It Looks like it only leaves about 5 inches of radiating area . Does this woofer have a very large X max.
Regards Ian
Regards Ian
Yes . Its polk i saw a small sticker on box written polk. but what model is it?
The measurements i just took.
Fs=37.5 Hz
Qms=5.35
Qes=0.35
Qts=0.33
Vas=0.61 Cu feet. and yes its written RD-1045-1 any comments how to use it ?
The measurements i just took.
Fs=37.5 Hz
Qms=5.35
Qes=0.35
Qts=0.33
Vas=0.61 Cu feet. and yes its written RD-1045-1 any comments how to use it ?
Wow, the high excursion, low vas and high FS would make a tapped horn a good option. But four of them would be huge!
I think you could go with four seperate ported enclosures, maybe 3.5 cubic foot a piece, each with 2 woofers with one inverted (push pull, not iso). I suppose a single 6 inch port or a large slot port tuning down to the 30hz range would be good. I have no software available now, so I am just guessing.
I think you could go with four seperate ported enclosures, maybe 3.5 cubic foot a piece, each with 2 woofers with one inverted (push pull, not iso). I suppose a single 6 inch port or a large slot port tuning down to the 30hz range would be good. I have no software available now, so I am just guessing.
Not convinced about Vas. i measured it in a box of 0.95 Cuft. Can anyone help finding the T/s parameters online.
i am going for 4 boxes. 1.5 cufeet each with dual 3 inch ports . tuned to 33-35 Hz. dont know about Xmax. Will buy more of these to get some damn good bass arrray. Like i said its available for 30 USD per pair brand new in a disposed lot imported by a local guy.
The bucking magnet indicates its intended for HT application. Can i use two in pull push configuration magnets back to back and two ports one on front and one on back. The reason for pull push is presumed less port noise. i can use one port at back but it will be too long to be practical.
Still any links for the subwofeer.
Still any links for the subwofeer.
the push pull alignment lowers distortion. The wouldn't be back to back. You would simply mount one driver inverted and wire it out of phase. that is all.
Two four inch ports I think would be OK. With these high excursion woofers you want as much port volume as you can get and still have a reasonable enclosure design.
I can pump these into winisd tonight and see what I can come up with, I am not a fan of acoustic suspension for home subwoofer use, so I will design a ported configuration in addtion to modeling a few bandpass examples as well. It may work great in a 6th order bandpass design.
Two four inch ports I think would be OK. With these high excursion woofers you want as much port volume as you can get and still have a reasonable enclosure design.
I can pump these into winisd tonight and see what I can come up with, I am not a fan of acoustic suspension for home subwoofer use, so I will design a ported configuration in addtion to modeling a few bandpass examples as well. It may work great in a 6th order bandpass design.
here it goes. Polk PSW 404, 150w RMS, the dimensions gives a total internal volume assuming the 3/4 inch mdf as 1.48 Cu feet, so exluding driver, bracing, vent , amp plate i think it would be around 1.2 Cu feet ?
here is the link :Polk Audio PSW404 Powered subwoofer at Crutchfield.com
Any suggestions ?
here is the link :Polk Audio PSW404 Powered subwoofer at Crutchfield.com
Any suggestions ?
-3db stated at 32 Hz. Any idea how should i model it i want to use 8 of them/pull push. regards.
I can run through the software tonight. I will model a ported enclosure for two drivers. I am assuming low bass extension is your primary concern.
Push Pull models the same as any ported speaker.
Try turning one around in your present box to see if the back vent makes whistling noises, noises can be far more annoying than the even order harmonic distortion that PP reduces.
I assumed that the air moved by the cone was equal on both sides of the cone, so reversing a driver would have no effect on the port noise. If I am wrong I surely want to know this, so I can compensate for it in future designs.
Yes. I am confused. when we mount woofers in pull push mode , one on front and one on back side of box i.e. magnets facing each other and wired out of phase then the volume displaced by outward motion of the front woofer would almost be equal to the volume pushed inside by the rear woofer, so the net air movement would be less and hence less port noise ?????? does it make any sense .
BTW the ports are going on rear. Is 0.75 Cuft good enough volume for decent bass extension. around 30 Hz -3db point
yes
it tells me you havent understood how it works
that is if I understand what you are saying
both cones should move in or out(of the box), simultaniously
no matter how you mount them
or else you create a dipole effect
Agreed. i know when wired out of phase and mounted inverse both cones would move in one direction simultaneously. But my point is can we put a port firing in phase with rear woofer but out of phase with front woofer. ??
BTW what do you suggest could be approximate size for 10 inch ported box with around 33 Hz tunning ???? WinISD data does not allow to go more than 0.5 cufeet whereas the polk has used it in around 1.0 cu feet ?
BTW what do you suggest could be approximate size for 10 inch ported box with around 33 Hz tunning ???? WinISD data does not allow to go more than 0.5 cufeet whereas the polk has used it in around 1.0 cu feet ?
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