Jack: what is up with the AR & Jensen woofers?
Jack:
I'm shocked that the AR & Jensen woofers are still available after all this time, or am I reading the current sheet incorrectly? I know the AR woofer is a bit odd, but both of them seem to be a very good value. Could you suggest some ideas on ways for people to use them with good results?
I keep thinking that a couple of those Jensens on a big open baffle would be really nice, and not expensive. The AR I don't know how to use.
Thanks!
Jack:
I'm shocked that the AR & Jensen woofers are still available after all this time, or am I reading the current sheet incorrectly? I know the AR woofer is a bit odd, but both of them seem to be a very good value. Could you suggest some ideas on ways for people to use them with good results?
I keep thinking that a couple of those Jensens on a big open baffle would be really nice, and not expensive. The AR I don't know how to use.
Thanks!
Regarding the AR woofer,
How high can it be crossed? 1200?1400?
I have the very same question. I've been eying both the AR woofer and the Jensen for a while now. I read earlier that you do not have frequency response plots for the AR woofer. Would you happen to have Le? That would at least give some idea.....
Thanks,
Markus
JND,
To get the best performance out of the M-60, you really need to notch out the peak in the woofer response at 5kHz. The passive xover does this. Your off the shelf active xover won't do this. You will need to build a bandpass notch filter to do it.
To use the Foster WF-100k amplifier to drive the woofer section in the M-60, you will need to bypass the LP xover in the WF-100k. Check the circuit for any other RC shunt filters along the way. Calculate their cutoff frequency and if any are within 5x of your desired woofer LP frequency, adjust them to be higher up.
To determine the correct boost, Q and F for the HP, model the woofer/cabinet system and the electrical filter in any of the standard free box modeling programs. You don't need the woofer parameters. Just put a woofer into a sealed box and adjust the woofer parameters until the Qcb and Fcb match the measured system response.
To do a digital filter for the M-60 is going to require a lot more work. You will need to measure the transfer function of the drivers in the box, use software such as Matlab to make an inverse filter, then use some convolution software to do the real time processing in your PC.
To get the best performance out of the M-60, you really need to notch out the peak in the woofer response at 5kHz. The passive xover does this. Your off the shelf active xover won't do this. You will need to build a bandpass notch filter to do it.
To use the Foster WF-100k amplifier to drive the woofer section in the M-60, you will need to bypass the LP xover in the WF-100k. Check the circuit for any other RC shunt filters along the way. Calculate their cutoff frequency and if any are within 5x of your desired woofer LP frequency, adjust them to be higher up.
To determine the correct boost, Q and F for the HP, model the woofer/cabinet system and the electrical filter in any of the standard free box modeling programs. You don't need the woofer parameters. Just put a woofer into a sealed box and adjust the woofer parameters until the Qcb and Fcb match the measured system response.
To do a digital filter for the M-60 is going to require a lot more work. You will need to measure the transfer function of the drivers in the box, use software such as Matlab to make an inverse filter, then use some convolution software to do the real time processing in your PC.
Yes, the spreadsheet on the website is up to date. I honestly can't believe how often I get asked this question. Here is the magic answer, that works for all Microsoft software:
Open the spreadsheet.
Select the File menu.
Select Properties.
Click the General or Statistics tab.
This will show the last date that the file was modified.
A good combination for the AR 12" is to put it in a 2cu ft enclosure with a port tuned to 30Hz. Apply a 2nd order HP filter in the WF-100k tuned to 30Hz with a Q of 1.3 (2.3dB boost). This will give you a system that is -3dB at 33Hz.
I would not cross the AR 12" above 500Hz. It has a poly cone that is not rigid enough to go much higher. It would work well for a 3-way system.
I'll try to measure some Le data for the AR 12". It should be around 1.7mh based on the VC geometry.
I have some frequency response and distortion data for the Jensen 15", but it is all measured in free air, so it takes some careful analysis to see what is really going on. I'll try to post it on the website.
Open the spreadsheet.
Select the File menu.
Select Properties.
Click the General or Statistics tab.
This will show the last date that the file was modified.
A good combination for the AR 12" is to put it in a 2cu ft enclosure with a port tuned to 30Hz. Apply a 2nd order HP filter in the WF-100k tuned to 30Hz with a Q of 1.3 (2.3dB boost). This will give you a system that is -3dB at 33Hz.
I would not cross the AR 12" above 500Hz. It has a poly cone that is not rigid enough to go much higher. It would work well for a 3-way system.
I'll try to measure some Le data for the AR 12". It should be around 1.7mh based on the VC geometry.
I have some frequency response and distortion data for the Jensen 15", but it is all measured in free air, so it takes some careful analysis to see what is really going on. I'll try to post it on the website.
Recently I figured out how to package some of the 5.25" Peerless woofers more time effectively. The only problem is that this costs more money, because I have to buy packaging materials. The upside is that it enables me to drop the minimum order for these drivers to a single pair for $30. I'll post an update on the website about this soon.
Jack:
Thanks.
In an earlier post you asked the community to pleeease look at the data package, I’m guilty of not following that request. Sorry.
I learned several things in the data, first, that the .adx files in the package were CSV formatted data points, and that these can be used as input to any number of design programs…at the same time I didn’t “see” the 5Khz peak in the woofer response (do’h, I thought it was far enough outside the passband of the filter). I clearly have some more learning (and homework) to do.
I have been checking the innards of the Foster amp to make sure any bandwidth limiting stuff has been dealt with. Nice build quality on these amps, a steal at the listed price!
You are exactly right on the necessary steps to do a digital crossover for the M-60s. I guess I thought that the filter arrangement for the M-60 as designed and implemented in the XdA could be cloned into another DSP engine. Is this not the case or is it an issue of proprietary (DEQX) information? Or is my naiveté showing again?
Bob
Thanks.
In an earlier post you asked the community to pleeease look at the data package, I’m guilty of not following that request. Sorry.
I learned several things in the data, first, that the .adx files in the package were CSV formatted data points, and that these can be used as input to any number of design programs…at the same time I didn’t “see” the 5Khz peak in the woofer response (do’h, I thought it was far enough outside the passband of the filter). I clearly have some more learning (and homework) to do.
I have been checking the innards of the Foster amp to make sure any bandwidth limiting stuff has been dealt with. Nice build quality on these amps, a steal at the listed price!
You are exactly right on the necessary steps to do a digital crossover for the M-60s. I guess I thought that the filter arrangement for the M-60 as designed and implemented in the XdA could be cloned into another DSP engine. Is this not the case or is it an issue of proprietary (DEQX) information? Or is my naiveté showing again?
Bob
NC DIY 2010 budget 2-way speaker using 5.25" NHT drivers
The drivers that Jack is talking about can be used in a nice budget 2-way system that I have been working on in collaboration with some people over at the Parts-Express forum. This is a 2-way passive speaker using some buyout cabinets with maple-finish veneer, the 5.25" NHT woofers, and a Vifa DQ25SC16 tweeter that Zaph has tested and found to be excellent. You can check out this thread for details:
possible recession buster DIY project - anyone interested??? - Techtalk at Parts-Express.com
as well as a page that has been started on Mark K's web site:
NC DIYAUDIO 2 way budget project
I am currently working out the last details with the CNC vendor who is making the tweeter adapter plates for the project and these should be available by April 1st.
Together, these drivers should result in an excellent, low distortion, budget 2-way system. I will be publishing the full details of where to source all the parts in a couple of weeks.
Here's a picture of prototype (the adapater plate is raw MDF):
-Charlie
The drivers that Jack is talking about can be used in a nice budget 2-way system that I have been working on in collaboration with some people over at the Parts-Express forum. This is a 2-way passive speaker using some buyout cabinets with maple-finish veneer, the 5.25" NHT woofers, and a Vifa DQ25SC16 tweeter that Zaph has tested and found to be excellent. You can check out this thread for details:
possible recession buster DIY project - anyone interested??? - Techtalk at Parts-Express.com
as well as a page that has been started on Mark K's web site:
NC DIYAUDIO 2 way budget project
I am currently working out the last details with the CNC vendor who is making the tweeter adapter plates for the project and these should be available by April 1st.
Together, these drivers should result in an excellent, low distortion, budget 2-way system. I will be publishing the full details of where to source all the parts in a couple of weeks.
Here's a picture of prototype (the adapater plate is raw MDF):
-Charlie
There are several updates to the website. Some information for the AR 12" has been added. Some measurements for the Jensen 15" have been added and another option for the WF-110k amplifier. I've updated the pricing and shipping policies for the Peerless 5.25" woofers (080 and 081).
Bob,
It is not a simple thing to take the DEQX generated filters and just export them to another DSP box.
ADX is the file extension that Audio Precision uses for ASCII format. Why they don't just use TXT, I don't know.
Bob,
It is not a simple thing to take the DEQX generated filters and just export them to another DSP box.
ADX is the file extension that Audio Precision uses for ASCII format. Why they don't just use TXT, I don't know.
AR12" upper on-axis frequency response limit
Jack,
How high in frequency does the on-axis passband of the AR12 extend? These drivers have enough SPL at 2.83V (REF 1W/1m into 8 ohms) that they might be used as woofers in those popular "Econowave" projects that everyone is doing these days. In order to be workable, they would need to cross over to a horn loaded compression driver (Selenium D220Ti for example) at 1.5 kHz or higher. I know that this is pushing the limits of a 12" driver, but I am not familiar with this driver's construction and how far the usable range extends above 500Hz.
Can you comment on this?
-Charlie
Jack,
How high in frequency does the on-axis passband of the AR12 extend? These drivers have enough SPL at 2.83V (REF 1W/1m into 8 ohms) that they might be used as woofers in those popular "Econowave" projects that everyone is doing these days. In order to be workable, they would need to cross over to a horn loaded compression driver (Selenium D220Ti for example) at 1.5 kHz or higher. I know that this is pushing the limits of a 12" driver, but I am not familiar with this driver's construction and how far the usable range extends above 500Hz.
Can you comment on this?
-Charlie
Charlie,
I haven't measure the midrange response of the AR 12" woofers in a long, long time. I don't remember what they look like. Given that they have a straight walled polypropylene cone with a rubber surround, I doubt they have extension much past 1kHz. If they do go past 1kHz, it won't be pretty. If I have time to measure one, I'll try to do it.
I don't have any M2.9 foam strips. You can try NHT, but I doubt they do.
I haven't measure the midrange response of the AR 12" woofers in a long, long time. I don't remember what they look like. Given that they have a straight walled polypropylene cone with a rubber surround, I doubt they have extension much past 1kHz. If they do go past 1kHz, it won't be pretty. If I have time to measure one, I'll try to do it.
I don't have any M2.9 foam strips. You can try NHT, but I doubt they do.
I've been holding onto three of the VR-X kits for about 6 months for someone. They have completely flaked out, so now I'm putting these last three kits up for sale. The price is $208 per kit. $624 total plus shipping. You have to purchase all three kits. I don't want to sell two and get stuck with the third.
There may be three complete cabinets available for them also. I should have photos of these in the next few days. I don't know what the price will be for the cabinets yet.
NHT drivers and electronics surplus sale
There may be three complete cabinets available for them also. I should have photos of these in the next few days. I don't know what the price will be for the cabinets yet.
NHT drivers and electronics surplus sale
NHT 2.5I drivers
Hello: I am new to this site, I am looking at a pair of NHT 2.5I and wanted to know if the peerless 8 in woofers are still availible. NHT part number was npt-11-047-1 . The speakers are in good shape but just wanted extra drivers just in case. I foud a spread sheet list of NHT parts but I do not know if the list is kept updated. Can anyone help. Thank you
Hello: I am new to this site, I am looking at a pair of NHT 2.5I and wanted to know if the peerless 8 in woofers are still availible. NHT part number was npt-11-047-1 . The speakers are in good shape but just wanted extra drivers just in case. I foud a spread sheet list of NHT parts but I do not know if the list is kept updated. Can anyone help. Thank you
Yes, go to this web site:
NHT drivers and electronics surplus sale
and do a search for that part number. They cost $14 each. There is a minimum order. Make sure to read all the info at the top and bottom of the page.
Send an EMail to Jack Hidley (see link at bottom of page) to place the order.
-Charlie
NHT drivers and electronics surplus sale
and do a search for that part number. They cost $14 each. There is a minimum order. Make sure to read all the info at the top and bottom of the page.
Send an EMail to Jack Hidley (see link at bottom of page) to place the order.
-Charlie
Foster WF-100K subwoofer amp?
In regard to the Foster WF-100K amp, are the figures in the "2nd_order_HP_filter_calculator" with or without the spectral tilt 10k mod? If without the mod, what is the setting of VR603? Thanks and sorry that I'm so late with a question of a year old discussion. Ray C.
In regard to the Foster WF-100K amp, are the figures in the "2nd_order_HP_filter_calculator" with or without the spectral tilt 10k mod? If without the mod, what is the setting of VR603? Thanks and sorry that I'm so late with a question of a year old discussion. Ray C.
S-80 sub with xDs speakers
Don't know if Jack is still around . I'm a happy owner of an xD 2.1 system. Been looking for another xDw , but hard to find now. I came upon an S-80 sub. Would anyone know if the S-80 will intergrate with the xDs monitors using the standard xDa firmware? I realize I cannot use both the S-80 and the xDw , but I'm using my system for HT also and would like the added power. Curious if the eq needed is the same for both subs , and also how high the S-80 can go using it with an xDa.
Don't know if Jack is still around . I'm a happy owner of an xD 2.1 system. Been looking for another xDw , but hard to find now. I came upon an S-80 sub. Would anyone know if the S-80 will intergrate with the xDs monitors using the standard xDa firmware? I realize I cannot use both the S-80 and the xDw , but I'm using my system for HT also and would like the added power. Curious if the eq needed is the same for both subs , and also how high the S-80 can go using it with an xDa.
