I just got my hand on a new pair of these 15" woofers, and have found the specifications on their web site: http://www.speakerplace.com/replacement.asp
Have anybody in here any experience with these woofers??
As I am mostly into amplifiers, my knowledge about speaker cabinets are limited. Should these be fitted in a closed or vented box, and how big should the cabinet be for lowest frq. response?
Here are the specifications:
Frq. response: 19Hz-2 kHz
FS: 19.09Hz
VAS cu.ft.: 27.04
SPL 1w1m: 91,2
QM: 4.80
QE: 0.62
Xmax: 7.1mm
Magnet: 38oz
VC Diameter: 2.0in
Power RMS: 175
Power Peak: 350
Have anybody in here any experience with these woofers??
As I am mostly into amplifiers, my knowledge about speaker cabinets are limited. Should these be fitted in a closed or vented box, and how big should the cabinet be for lowest frq. response?
Here are the specifications:
Frq. response: 19Hz-2 kHz
FS: 19.09Hz
VAS cu.ft.: 27.04
SPL 1w1m: 91,2
QM: 4.80
QE: 0.62
Xmax: 7.1mm
Magnet: 38oz
VC Diameter: 2.0in
Power RMS: 175
Power Peak: 350
To be honest, Jan, I think you have a pair of woofers meant for putting into a door or a wall between rooms.
Your Qts works out to .56. Ported, you would need an enclosure of at least 27 cu ft, and that counts a little "boom".
A sealed enclosure would be in the 20 cu ft range.
There is another possiblility, of which I am familiar, but cannot give details.
For sealed enclosures, there is a circuit, passive I believe, called a Linkwitz Transform which is used to put woofers in sealed boxes smaller than optimum.
If nobody responds with details of how to apply the Linkwitz Transform, I would suggest you start a thread about it, or do the search in this forum. It is a very popular circuit, and it seems to be used for people with a situation similar to yours-putting woofers in sealed boxes smaller than optimum.
I don't usually use sealed boxes for my woofers, so I never completely investigated it.
Here is Linkwitz' website. I am not sure where, if anywahere, he gives details on his Linkwitz Transform circuit:
www.linkwitzlab.com
I am sure you will be able to find many people on this forum who have used this circuit. It is mentioned very often. In fact, it is so familiar that it is frequently simply called an LT circuit!
Your Qts works out to .56. Ported, you would need an enclosure of at least 27 cu ft, and that counts a little "boom".
A sealed enclosure would be in the 20 cu ft range.
There is another possiblility, of which I am familiar, but cannot give details.
For sealed enclosures, there is a circuit, passive I believe, called a Linkwitz Transform which is used to put woofers in sealed boxes smaller than optimum.
If nobody responds with details of how to apply the Linkwitz Transform, I would suggest you start a thread about it, or do the search in this forum. It is a very popular circuit, and it seems to be used for people with a situation similar to yours-putting woofers in sealed boxes smaller than optimum.
I don't usually use sealed boxes for my woofers, so I never completely investigated it.
Here is Linkwitz' website. I am not sure where, if anywahere, he gives details on his Linkwitz Transform circuit:
www.linkwitzlab.com
I am sure you will be able to find many people on this forum who have used this circuit. It is mentioned very often. In fact, it is so familiar that it is frequently simply called an LT circuit!
Yes. it is.
I believe the Linkwitz Transform can be used with ported enclosures as well. I can contact some members who have used it, if nobody answers.
I blieve another option is the Variovent, or aperiodic. They sell the ports in Parts Express and European dealers, very inexpensive. I think this makes a "lossy box" which also helps to settle down the "boom" in a sealed box. We have threads on this I can refer you to-gotta run to work now.
In short, I do think it might be possible to put this in a box of 5 or 6 cubic feet-not sure. Who knows-maybe even smaller.
I believe the Linkwitz Transform can be used with ported enclosures as well. I can contact some members who have used it, if nobody answers.
I blieve another option is the Variovent, or aperiodic. They sell the ports in Parts Express and European dealers, very inexpensive. I think this makes a "lossy box" which also helps to settle down the "boom" in a sealed box. We have threads on this I can refer you to-gotta run to work now.
In short, I do think it might be possible to put this in a box of 5 or 6 cubic feet-not sure. Who knows-maybe even smaller.
Thanks for your efforts... I will absolutely look into that!
I saw that I have forgotten to write that QT= 0.55. and that the "suspension" is very very stiff.
As it can't be true that they can keep on selling woofers that demands a whole house as cabinet, I tried to hook on up in a spare closed cabinet that I have. This cabinet is app. 0,5 M3 (=1½ cu ft I think), and it works very impressing. The sound is very "tight" with a lot of kick (tested up to 200W).
I have tested it with a test CD that I have, and the woofer works well down to app. 40 Hz, where it the sound became quite "woppeling"... However this frq. has the same wave lenght as my livingroom (8.5 meters = 25 ft??), so I think the problen is caused by that..... (concrete walls
Do you have any experience with this?
I saw that I have forgotten to write that QT= 0.55. and that the "suspension" is very very stiff.
As it can't be true that they can keep on selling woofers that demands a whole house as cabinet, I tried to hook on up in a spare closed cabinet that I have. This cabinet is app. 0,5 M3 (=1½ cu ft I think), and it works very impressing. The sound is very "tight" with a lot of kick (tested up to 200W).
I have tested it with a test CD that I have, and the woofer works well down to app. 40 Hz, where it the sound became quite "woppeling"... However this frq. has the same wave lenght as my livingroom (8.5 meters = 25 ft??), so I think the problen is caused by that..... (concrete walls
Do you have any experience with this?
ACD said:
Jan:
If your closed cabinet is 0.5 cubic meters, that is about 17 cu feet. In which case, I would think that this speaker would have a final Qtc of about 1.6 or so, assuming the published specs are correct. You should be +6dB or so at 30 Hz, which is your Fc, (the resonant frequency of the speaker in the box).
As far as rooms, concrete walls, etc. I have put four 15's in the door of a 50 cu ft closet in the middle of a room, but really didn't do any great response tests on it. All I can say is, the bass sounded like it came from The Center Of The Earth.
Oops. Make that about +4 dB at Fc, which in your case, is 30 Hz, (in this 17 cu ft box).
Here is the chart of your closed box response shapes for various values of Qtc. Feel free to ask questions. Gotta go. Will be back tonight.
http://www.diyaudio.com/forums/showthread.php?threadid=8071&highlight=Response+shapes
Here is the chart of your closed box response shapes for various values of Qtc. Feel free to ask questions. Gotta go. Will be back tonight.
http://www.diyaudio.com/forums/showthread.php?threadid=8071&highlight=Response+shapes
Keltic:
Thanks for sharing your wisdom, and appologies for my poor
"M3 > cu ft" calcs
I must learn it some day....
Thanks for the link.... I will try some of the software.
See you later
Thanks for sharing your wisdom, and appologies for my poor
"M3 > cu ft" calcs
I must learn it some day....Thanks for the link.... I will try some of the software.
See you later
Jan, just a thought, but it might be that the published specs have a typo, it wouldn't be the first time! Do you have access to any measuring equipment to check them out?
Hello Pink:
Thanks for your input.
I also think it must be a typo... They seems to work fine in a closed cabinet
I have the meassuring gear next week, so lets see what they say...
Thanks for your input.
I also think it must be a typo... They seems to work fine in a closed cabinet
I have the meassuring gear next week, so lets see what they say...
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