mworthin
Thanks for the link. For the price of the pcb and parts i can purchase 2 MiniDsp HDs.I can also purchase 2 kits from the DIY store and hook them together. if I knew what I was doing (I don't). This may be the answer if someone could help configure the OB sub woofer and revised mid range since the bass booost will not be needed. MicroCap is beyond my capabilities.
You should read Nelson's paper on the 6-24 crossover, the 6-24 allows changes to the crossover center frequency using pots on the PCB.
On page 11 of the PDF file, is a link to Mike Rothacher's filter application, which can be used for either the 6-24 and the LX mini.
http://doublesecretlabs.com/apps/passxo
The LX mini and 6-24 use the same filters and buffers, the 6-24 allows adjustment of the center point of the filters along with 6dB, 12dB, 18dB and 24dB slopes.
The 6-24 thread has comments from several members regarding sub-woofer and balanced versions.
I am into the LX-mini loudspeaker! And would like your take based on the following:
1. I use an open baffle LS, Spatial Audio M4 Triode Master so I am very familiar with open baffle sound.
2. My power amplifiers are the following: Pass XA-25, the Vfet P channel, Acurus 100 w/c and a Class D Crown amp in a closet.
3. So, I was wondering if I could get by, implementing this set up with the Lx-mini:
a. XA25 for the woofer
b. Vfet for the tweeter
c. Acurus for the Ripole -DIY- subwoofers I currently use
Comment: The XA-25 and Vfet sound very similar to me, the Vfet is a little more smooth or sweeter
I already have the FW LX mini xover which I presently use alternating between a DSP HD mini, biamplifying the system at 100 hz with a 4 db boost at 30 hz between the Spatials and SW's.
works pretty well!
I've read about a minimum power requirements for this system, but the XA-25 I am sure can get the job done. My doubt is about the Vfet which is only 10w.
Don't know I could balance the gain settings using the pots in the LX- xover due to the gain and power differences between the 2 amps.
BTW, I would order a new LX Xover kit and built it as it comes for the LX-mini LS
The SW's would be crossed at whatever frequency is needed, using my present xover set a lower frequency. I guess 45 hz or so.
I will appreciate your comments or suggestions for this crazy idea..
Thanks
1. I use an open baffle LS, Spatial Audio M4 Triode Master so I am very familiar with open baffle sound.
2. My power amplifiers are the following: Pass XA-25, the Vfet P channel, Acurus 100 w/c and a Class D Crown amp in a closet.
3. So, I was wondering if I could get by, implementing this set up with the Lx-mini:
a. XA25 for the woofer
b. Vfet for the tweeter
c. Acurus for the Ripole -DIY- subwoofers I currently use
Comment: The XA-25 and Vfet sound very similar to me, the Vfet is a little more smooth or sweeter
I already have the FW LX mini xover which I presently use alternating between a DSP HD mini, biamplifying the system at 100 hz with a 4 db boost at 30 hz between the Spatials and SW's.
works pretty well!
I've read about a minimum power requirements for this system, but the XA-25 I am sure can get the job done. My doubt is about the Vfet which is only 10w.
Don't know I could balance the gain settings using the pots in the LX- xover due to the gain and power differences between the 2 amps.
BTW, I would order a new LX Xover kit and built it as it comes for the LX-mini LS
The SW's would be crossed at whatever frequency is needed, using my present xover set a lower frequency. I guess 45 hz or so.
I will appreciate your comments or suggestions for this crazy idea..
Thanks
I can't speak for the LX mini speakers, I'm using SLOB with CUBE FC-8 full range and Eminence 4015 15" woofers.
I started with using the P channel VFET amp for the full range drivers and an N channel VFET for the woofers. I had no trouble balancing the treble and bass using the input pots on the xover. I thought I was crazy trying to drive the 15" woofers with the 7 - 10 watt VFET amp, yet it worked just fine.
I have since swapped out the N channel VFET with a FIRSTWATT J2 clone. The input pots on the xover are now both set to zero and the bass sound seems fuller, probably due to the SiC JFET output devices.
10 years ago, I never would have considered buying an amp that wasn't at LEAST 100 W/channel, I even sold my McIntosh amp (which I had lusted after for years), after building the M2x. I no longer worry about amplifier wattage anymore, which I feel is similar to "range anxiety" with EV's.
I do recommend using input pots on the xover which can be mounted on the front panel for ease of adjustment. I used the blue ALPS pots on mine, I wasn't concerned about using very high quality pots on the inputs since I only adjust them when I swap amps. I did however, swap the J113 for 2SK170's in the signal path, I wanted lower noise and I had lots of them in stock.
Attachments
At 93db sensitivity and since the minimum power requirement for the speaker is 10 watts, I think this would be a winning combination as long as you don't expect to play them at concert levels all day and night. For normal listening the VFET is magical on compression drivers. Try it and report back! Also, pictures would be appreciated. 🍿
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Hello All,
I have a pair of LX-Mini’s that built and have been listening to for many years now. I’m using nanoDIGI 2x8 version of miniDSP, running as a 3-Way stereo.
It really sounds great, but the ASP is very interesting. It would also free up the DSP to fiddle with some other drivers I have on the shelf.
Anyway, after reading all the posts in this thread, I have some questions. I’m wondering if it’s possible to implement the xo/filter that I want for bass duty.
I have 10” Peerless drivers in a sealed box, running on a DSP file from Davey over at OPLUG. Davey did really great with the design for that driver DSP xo. The big question is how to do it in ASP?
The tops will be easy, as I understand I just need to get the kit at DIY Audio store, and I can order it with matches JFets, and parts needed to make the curves that NP and SL came up with for 2way lxmini, right?
So then I get another board to run the bass woofer. Not sure if I should be looking at the Pass LX Mini ASP board, or the Pass 6-24 ASP board. At this point I’m thinking maybe the additional filter section on lxmini asp board might be useful?
I understand there’s a 3rd board that NP did which is available from Frank at Linkwitz Magic or whatever that store is called. 3-way and Balanced/XLR seems ideal, BUT my setup with the 10”Peerless surely will have different curves than the xo/filter designed for the lxmini+ or lxmini studio. I also think that board would be more difficult for me to figure out how to customize for my needs. So probably this option is not the best route for me.
I want to make xo/filter for the 10” Peerless that will be:
Low-shelf, 25Hz, +16db, Q=0.7.
Peak, 70Hz, -4db, Q=1.
Xover LP 60Hz LR12db/oct.
Obviously, my next step will be to figure out how to download and use the tools, like MicroCap to see if I can come up
with what I need.
My real problem is that if I’m not successful, I won’t know if it’s because I don’t know how to use microcap yet, or if the failure is because I have an impossible goal which is beyond the intended capabilities of this PCB.
I’m worried about the Low-shelf, 25Hz, +16db, Q=0.7
I think in one place I read that there is no gain on this board (or rather gain=1) which makes me think I won’t be able to have anything with +16dB in the filter. In another place I read there’s a filter in the board that makes a little boost on the mid-wood +6dB at 50Hz. Should I be able to utilize that part of the board changing the values of some Cs and Rs for the 10” woofer.
I think I also saw a post in here somewhere that Papa said one can make a shelf filter with this board. I’m not sure if there may be limitations.
I would super appreciate if someone can let me know if my filter goal is even possible.
I welcome all thoughts about this.
I have a pair of LX-Mini’s that built and have been listening to for many years now. I’m using nanoDIGI 2x8 version of miniDSP, running as a 3-Way stereo.
It really sounds great, but the ASP is very interesting. It would also free up the DSP to fiddle with some other drivers I have on the shelf.
Anyway, after reading all the posts in this thread, I have some questions. I’m wondering if it’s possible to implement the xo/filter that I want for bass duty.
I have 10” Peerless drivers in a sealed box, running on a DSP file from Davey over at OPLUG. Davey did really great with the design for that driver DSP xo. The big question is how to do it in ASP?
The tops will be easy, as I understand I just need to get the kit at DIY Audio store, and I can order it with matches JFets, and parts needed to make the curves that NP and SL came up with for 2way lxmini, right?
So then I get another board to run the bass woofer. Not sure if I should be looking at the Pass LX Mini ASP board, or the Pass 6-24 ASP board. At this point I’m thinking maybe the additional filter section on lxmini asp board might be useful?
I understand there’s a 3rd board that NP did which is available from Frank at Linkwitz Magic or whatever that store is called. 3-way and Balanced/XLR seems ideal, BUT my setup with the 10”Peerless surely will have different curves than the xo/filter designed for the lxmini+ or lxmini studio. I also think that board would be more difficult for me to figure out how to customize for my needs. So probably this option is not the best route for me.
I want to make xo/filter for the 10” Peerless that will be:
Low-shelf, 25Hz, +16db, Q=0.7.
Peak, 70Hz, -4db, Q=1.
Xover LP 60Hz LR12db/oct.
Obviously, my next step will be to figure out how to download and use the tools, like MicroCap to see if I can come up
with what I need.
My real problem is that if I’m not successful, I won’t know if it’s because I don’t know how to use microcap yet, or if the failure is because I have an impossible goal which is beyond the intended capabilities of this PCB.
I’m worried about the Low-shelf, 25Hz, +16db, Q=0.7
I think in one place I read that there is no gain on this board (or rather gain=1) which makes me think I won’t be able to have anything with +16dB in the filter. In another place I read there’s a filter in the board that makes a little boost on the mid-wood +6dB at 50Hz. Should I be able to utilize that part of the board changing the values of some Cs and Rs for the 10” woofer.
I think I also saw a post in here somewhere that Papa said one can make a shelf filter with this board. I’m not sure if there may be limitations.
I would super appreciate if someone can let me know if my filter goal is even possible.
I welcome all thoughts about this.
The LX-mini is 6dB slopes, since you want 12dB, the 6-24 would work. You don't need to use microcap, on page 11 of the 6-24 white paper, Nelson has a link to an app designed by Mike R. that will calculate resistor and cap values based on the crossover center point.
The 6-24 also allows adjustment of the center point and the slope, this should help with finding the ideal for your bass woofer.
My opinion.
@AlexQS The circuit you're looking for is a Linkwitz-Transform. Originally this was implemented with an analog realization........but so much easier nowadays with DSP processing.
You won't be able to achieve the exact EQ curve I implemented in the LXmini+ setup, but you can get pretty darn close.
All the info you need is on the appropriate Linkwitzlab web page. Any of the latest simulation programs can be used to model this. Or, you can use SL's own Excel spreadsheet he put together MANY years ago.
https://www.linkwitzlab.com/filters.htm#9
Dave.
You won't be able to achieve the exact EQ curve I implemented in the LXmini+ setup, but you can get pretty darn close.
All the info you need is on the appropriate Linkwitzlab web page. Any of the latest simulation programs can be used to model this. Or, you can use SL's own Excel spreadsheet he put together MANY years ago.
https://www.linkwitzlab.com/filters.htm#9
Dave.
I thought so. You cleared my confusion before I could even ask about that. Yep, it’s LR2
Dave, thank you. I couldn’t remember the name Linkwitz Transform.
Really appreciate being guided in the right direction.
This helps. I read so much today my mind is boggeling. I came across what you referenced but couldn’t remember where it was. I may need that soon. Thank you!
SL produced some boards that would be perfect for this application. Unfortunately, there are no more available.....unless you can find a set used.
https://www.linkwitzlab.com/Pluto/woofer-asp.htm
The current proprietor of Linkwitz Lab has no interest in the DIY approach to the projects, so.......
It is what it is.
A few years back I gauged the interest in reproducing some similar boards with footprints for current components, but I didn't get any interest at all. The DSP approach is so much simpler/easier/cheaper.
Dave.
I havent finished my build, but I am planning on using a Threshold s200 and a VFET lottery amp. But I am also considering selling the Threshold and using an Odyssey Stratos in its place.
Just fired up my ACN for the first time and ran through testing, Similar to @namghiwook, my measurements for R13-16, and 35-38 were all near 1.5 volts.
The only other anomaly I noticed when building was r17-20 provided with the jfets were 10k, vs the 4k in the original article. unsure if there is a correlation.
Are my readings acceptable? all the remaining tests were within spec.
thanks, can't wait to A/B it with my minidsp HD.
The only other anomaly I noticed when building was r17-20 provided with the jfets were 10k, vs the 4k in the original article. unsure if there is a correlation.
Are my readings acceptable? all the remaining tests were within spec.
thanks, can't wait to A/B it with my minidsp HD.