Thanks for keeping this extraordinary tool alive!
I will be showing my ignorance but I am confused by placing active filters after the amplifier block. I doubt it makes any difference but it just seems out of character.
I assume a high pass filter option will eventually be added?
It would be neat if one could adjust the "Q" like you can with the passive components since you have made it clear to folks those set values are just benchmarks. What works best is best.
Hope the New Year is a good one for you. You have certainly made ours better. I am in an agreement with other who have mentioned setting up something to show our appreciation with more than words, Broskie has a PATREON setup which does sound more appropriate than a PAYPAL link. More in keeping with the quality of your product.
I will be showing my ignorance but I am confused by placing active filters after the amplifier block. I doubt it makes any difference but it just seems out of character.
I assume a high pass filter option will eventually be added?
It would be neat if one could adjust the "Q" like you can with the passive components since you have made it clear to folks those set values are just benchmarks. What works best is best.
Hope the New Year is a good one for you. You have certainly made ours better. I am in an agreement with other who have mentioned setting up something to show our appreciation with more than words, Broskie has a PATREON setup which does sound more appropriate than a PAYPAL link. More in keeping with the quality of your product.
Hi Rick,
Well, think of the "power amp" as just a signal source when followed by an active filter, and all the active (triangle shaped) blocks as being like little power amps or power buffers.
There are high pass filters (for butterworth and LR shapes, in a Filter device), see the "Filter Type" dropdown box. I didn't do it for Bessel since (1) it makes no sense, the Bessel is only maximally flat delay in its passband for a low pass and not good for much at all as a high pass and (2) it was going to get difficult as the Bessel isn't as easily generated by its poles which are needed to figure highpass and bandpass. I only put in the Buttworth and the LR for those guys who have a Jones for the 'named' filter shapes, for that matter! I may do an adjustable Q section, but that only makes sense for 2-pole filters so the interface would get messy. You could always do one with the Opamp and resistors and capacitors, I guess, too.
BTW, XSim can't check for stability with the opamp or the Filter blocks in circuits, so just because what you design looks ok and stable, it might not really be. Designer beware!
Well, think of the "power amp" as just a signal source when followed by an active filter, and all the active (triangle shaped) blocks as being like little power amps or power buffers.
There are high pass filters (for butterworth and LR shapes, in a Filter device), see the "Filter Type" dropdown box. I didn't do it for Bessel since (1) it makes no sense, the Bessel is only maximally flat delay in its passband for a low pass and not good for much at all as a high pass and (2) it was going to get difficult as the Bessel isn't as easily generated by its poles which are needed to figure highpass and bandpass. I only put in the Buttworth and the LR for those guys who have a Jones for the 'named' filter shapes, for that matter! I may do an adjustable Q section, but that only makes sense for 2-pole filters so the interface would get messy. You could always do one with the Opamp and resistors and capacitors, I guess, too.
BTW, XSim can't check for stability with the opamp or the Filter blocks in circuits, so just because what you design looks ok and stable, it might not really be. Designer beware!
I know you could try out various "Q"s with the op amp block but it is so entertaining and enlightening when you can see the trends by holding those up and down buttons! I am not asking for anything! Only if it was an easy addition!
Maybe I need to re-load the software. I do not get the choice of highpass within the filter block. I must admit I am using this with UBUNTO and WINE and that could be the reason.
I will load it up on a WINDOWS machine and bet I see both of the choices. One never knows what will and won't work with WINE. Most of the time it works just fine but then there are those other times ...
I would never expect any tool to tell us EVERYTHING. Without the back and forth between XSim and real life one has no understanding of what XSIm is telling us. If it did everything, which would be impossible, there would be no fun left in audio at all!
Grateful in the extreme for this, Mr. Waslo. The audio parts suppliers should get on board with XSim. I think they could sell stuff to people who would have never considered trying their hand at DIY. DIY IS the future of audio. Only way us normal folks can get the sound we want at a cost we can afford.
And on the the other hand - those of us who have learned so much from this need a way to prove our appreciation. After mentioning PATREON I went to Broskie's site and became a patron there. He is not going to get rich from this but I bet it makes one enjoy what you are doing more along with motivating one to keep at it. when people say thanks with part of themselves. Words are nice but ...
I know my system has benefited GREATLY from your gifts.
Maybe I need to re-load the software. I do not get the choice of highpass within the filter block. I must admit I am using this with UBUNTO and WINE and that could be the reason.
I will load it up on a WINDOWS machine and bet I see both of the choices. One never knows what will and won't work with WINE. Most of the time it works just fine but then there are those other times ...
I would never expect any tool to tell us EVERYTHING. Without the back and forth between XSim and real life one has no understanding of what XSIm is telling us. If it did everything, which would be impossible, there would be no fun left in audio at all!
Grateful in the extreme for this, Mr. Waslo. The audio parts suppliers should get on board with XSim. I think they could sell stuff to people who would have never considered trying their hand at DIY. DIY IS the future of audio. Only way us normal folks can get the sound we want at a cost we can afford.
And on the the other hand - those of us who have learned so much from this need a way to prove our appreciation. After mentioning PATREON I went to Broskie's site and became a patron there. He is not going to get rich from this but I bet it makes one enjoy what you are doing more along with motivating one to keep at it. when people say thanks with part of themselves. Words are nice but ...
I know my system has benefited GREATLY from your gifts.
Just found out about this program, answered all my prayers.
I'm using .zma files directly exported from DATS and it works perfectly when set to "measured"
However I'm using TrueRTA which doesn't export response files as FRD.
But I realized that I can get FRD files from TrueRTA .txt response plots by just changing the file extension.
But the only way to get it to work in x-sim is to set the "FRD phase source" to "derived"
Am I doing this correctly? I mean it's working, but is it working as it should?
Thanks in advance.
I'm using .zma files directly exported from DATS and it works perfectly when set to "measured"
However I'm using TrueRTA which doesn't export response files as FRD.
But I realized that I can get FRD files from TrueRTA .txt response plots by just changing the file extension.
But the only way to get it to work in x-sim is to set the "FRD phase source" to "derived"
Am I doing this correctly? I mean it's working, but is it working as it should?
Thanks in advance.
Had a free morning to give this a shot, but ran into some glitches.
I made some REW measurements of each drivers in my OB setup, of course, no EQ, nothing.
Exported frd files to XSim and managed to get my XO curves looking as they should in a textbook. I saved the files as txt, and imported via the Browse button into the FIR filter of the miniDSP HD.
When I turned on the amp, there was nothing but loud pops and clicks. Switched off everything.
Went back to the miniDSP, cleared the taps, and opened the txt file to just copy, and paste into the Manual Setup of the miniDSP. Clicked PROCESS but it told me it didn't recognize ba10, ba9, ba8...., ba1. Clicked OK anyway and some lines were added into the Manual window.
Tried that, but the sound was all wrong.
Here's one of the txt file I got from XSim, trying to add a 4th order on my woofer... anything suspicious?
biquad1,
b0=0.1077816797281950,
b1=-0.1926415023641402,
b2=0.0853302376751767,
a1=1.9285318913179440,
a2=-0.9290023063571755,
biquad2,
b0=0.0596208103120864,
b1=-0.1101191397976303,
b2=0.0511370136512899,
a1=1.9635854419576840,
a2=-0.9642241261234304,
biquad3,
b0=0.3305060727804089,
b1=-0.5937630535208899,
b2=0.2723987954434808,
a1=1.8875272104353200,
a2=-0.8966690251383194,
biquad4,
b0=1.0028733657620980,
b1=-1.9877131411700540,
b2=0.9873013676793801,
a1=1.9877131411700540,
a2=-0.9901747334414778,
biquad5,
b0=0.9969554300066495,
b1=-1.9590539478314860,
b2=0.9734384644662352,
a1=1.9590539478314860,
a2=-0.9703938944728847,
biquad6,
b0=1.0002828804101920,
b1=-1.9977186892480370,
b2=0.9975320856201288,
a1=1.9977186892480370,
a2=-0.9978149660303205,
biquad7,
b0=0.9996983814244888,
b1=-1.9968206177409690,
b2=0.9973686095151097,
a1=1.9968206177409690,
a2=-0.9970669909395985,
biquad8,
b0=1.0005651162162220,
b1=-1.9952502335094060,
b2=0.9950697949166284,
a1=1.9952502335094060,
a2=-0.9956349111328508,
biquad9,
b0=1.0007935043372010,
b1=-1.9953989157406310,
b2=0.9953595520449681,
a1=1.9953989157406310,
a2=-0.9961530563821692,
biquad10,
b0=0.9991615206703384,
b1=-1.9909978733881320,
b2=0.9926849116434255,
a1=1.9909978733881320,
a2=-0.9918464323137638,
I made some REW measurements of each drivers in my OB setup, of course, no EQ, nothing.
Exported frd files to XSim and managed to get my XO curves looking as they should in a textbook. I saved the files as txt, and imported via the Browse button into the FIR filter of the miniDSP HD.
When I turned on the amp, there was nothing but loud pops and clicks. Switched off everything.
Went back to the miniDSP, cleared the taps, and opened the txt file to just copy, and paste into the Manual Setup of the miniDSP. Clicked PROCESS but it told me it didn't recognize ba10, ba9, ba8...., ba1. Clicked OK anyway and some lines were added into the Manual window.
Tried that, but the sound was all wrong.
Here's one of the txt file I got from XSim, trying to add a 4th order on my woofer... anything suspicious?
biquad1,
b0=0.1077816797281950,
b1=-0.1926415023641402,
b2=0.0853302376751767,
a1=1.9285318913179440,
a2=-0.9290023063571755,
biquad2,
b0=0.0596208103120864,
b1=-0.1101191397976303,
b2=0.0511370136512899,
a1=1.9635854419576840,
a2=-0.9642241261234304,
biquad3,
b0=0.3305060727804089,
b1=-0.5937630535208899,
b2=0.2723987954434808,
a1=1.8875272104353200,
a2=-0.8966690251383194,
biquad4,
b0=1.0028733657620980,
b1=-1.9877131411700540,
b2=0.9873013676793801,
a1=1.9877131411700540,
a2=-0.9901747334414778,
biquad5,
b0=0.9969554300066495,
b1=-1.9590539478314860,
b2=0.9734384644662352,
a1=1.9590539478314860,
a2=-0.9703938944728847,
biquad6,
b0=1.0002828804101920,
b1=-1.9977186892480370,
b2=0.9975320856201288,
a1=1.9977186892480370,
a2=-0.9978149660303205,
biquad7,
b0=0.9996983814244888,
b1=-1.9968206177409690,
b2=0.9973686095151097,
a1=1.9968206177409690,
a2=-0.9970669909395985,
biquad8,
b0=1.0005651162162220,
b1=-1.9952502335094060,
b2=0.9950697949166284,
a1=1.9952502335094060,
a2=-0.9956349111328508,
biquad9,
b0=1.0007935043372010,
b1=-1.9953989157406310,
b2=0.9953595520449681,
a1=1.9953989157406310,
a2=-0.9961530563821692,
biquad10,
b0=0.9991615206703384,
b1=-1.9909978733881320,
b2=0.9926849116434255,
a1=1.9909978733881320,
a2=-0.9918464323137638,
Rick, the latest build has provisions for variable Q second order sections (High-pass, Low-pass, and All-Pass), they are in the "PEQ" type blocks. At least they are in Windows! Also first order high-pass and low-pass.
http://libinst.com/Xsim/BetaTest/XSim3DSetup.exe
Index of /Xsim/BetaTest
Bill
Im looking for some help on upgrading, rebuilding some factory xo's from polk audio rti12's speakers. Im having a hard time of understanding certain parts of there midrange xo . And im alittle confused on why they (polk) seemed to choose cheybychev architecture on most of the xo.
I dont have measuring tools to make frd or zma files but i do have a factory xo schematic i can share here along with a woofer tester results on the woofer and a few T/S parameters on the midrange driver.
But what im mostly interested in is how there, idk , i guess ill call it a cascading bandpass on the mids work and there approximate slope type and xo points.
Hoping some of you xo gurus can help a guy out here and teach a old dog a few new tricks . Standing by !!
Im sorry if this post is in the wrong place or thread but it was my search for xo software to maybe model there schematic that brought me here. Thanks Harlen
I dont have measuring tools to make frd or zma files but i do have a factory xo schematic i can share here along with a woofer tester results on the woofer and a few T/S parameters on the midrange driver.
But what im mostly interested in is how there, idk , i guess ill call it a cascading bandpass on the mids work and there approximate slope type and xo points.
Hoping some of you xo gurus can help a guy out here and teach a old dog a few new tricks . Standing by !!
Im sorry if this post is in the wrong place or thread but it was my search for xo software to maybe model there schematic that brought me here. Thanks Harlen
What makes you think this is "Chebyshev" architecture (what is that exactly)? It appears to be basic 2nd order, first order lowpass on the midranges.
Also, you can't really say what the response shape is from just the crossover schematic, the drivers themselves also include acoustic filter poles that have to be considered. And the drivers' impedances also play into it. You only get the same electrical shape as the crossover's filter if the drivers have flat response way beyond the corner frequencies and the drivers have flat impedance. Which happens, essentially, never.
Also, you can't really say what the response shape is from just the crossover schematic, the drivers themselves also include acoustic filter poles that have to be considered. And the drivers' impedances also play into it. You only get the same electrical shape as the crossover's filter if the drivers have flat response way beyond the corner frequencies and the drivers have flat impedance. Which happens, essentially, never.
Cheybychev is a filter slope like bessel or butterworth but still has gain or ripple just above the xo point. Another way to say it is bessels have a Q of around .51 to.58, butterworths Q .700 to .750 , and then cheybychev with a Q around .9 to 1.1
The series parallel wiring on mids was/ is throwing me off some . The mids have a measured Re of 2.33 ohm fyi. Is the 10uf acting as the highpass of the band pass ? Polk states these are crossed at hp 120hz and 2000hz. Lp
The tweeter seems to be crossed near 4k, polk states the tweeter has a Re of 3.5 ohm.
220uf followed by a 1.3mh inductor creates a hp at 250hz at around 2.7 Re. With a Q of 1.11 Any more Re and the Q goes into out of range uses with severe ripple/gain . Maybe im overcomplicating things .
The series parallel wiring on mids was/ is throwing me off some . The mids have a measured Re of 2.33 ohm fyi. Is the 10uf acting as the highpass of the band pass ? Polk states these are crossed at hp 120hz and 2000hz. Lp
The tweeter seems to be crossed near 4k, polk states the tweeter has a Re of 3.5 ohm.
220uf followed by a 1.3mh inductor creates a hp at 250hz at around 2.7 Re. With a Q of 1.11 Any more Re and the Q goes into out of range uses with severe ripple/gain . Maybe im overcomplicating things .
That 2.33 Re on the mid drivers came from a non reliable source tho. I just ran a basic Re on them with a snapon fluke and measured it at around 3.2 ohms . I know thats very far from actual zma type data . I guess if i really want to PLAY in this project ill need to get setup to measure and make accurate frd and zma files.
Hello Oregonfarmer,
First of all, this is not a personal attack, but rather a clarification.
From reading your post 436, I get the impression you do not quite get Bill Waslo's remark about the architecture. Bill knows better than anyone else what a Chebychev filter and its associated pass-and stopband characteristics are.
The message Bill was trying to get across is that from typical RCL passive filter topology shown in the Polk diagram in post 434, the Chebychey properties -if any- cannot be seen or deducted.
In the schematic shown there is no such thing as "Chebychev architecture": the filter topology (architecture if you like) shown is not any different from electric first and second order BUT or LKR filter, simply made up from series and/or parallel L, C and R's.
Sorry, Bill to speak for you. But I could not resits responding to another Marketing Department (Matthew Polk& Friends, I assume?) claim about "architecture" , where there is none. Such a claim invariably leads to confusion.
Kind regards,
Eelco de Bode
First of all, this is not a personal attack, but rather a clarification.
From reading your post 436, I get the impression you do not quite get Bill Waslo's remark about the architecture. Bill knows better than anyone else what a Chebychev filter and its associated pass-and stopband characteristics are.
The message Bill was trying to get across is that from typical RCL passive filter topology shown in the Polk diagram in post 434, the Chebychey properties -if any- cannot be seen or deducted.
In the schematic shown there is no such thing as "Chebychev architecture": the filter topology (architecture if you like) shown is not any different from electric first and second order BUT or LKR filter, simply made up from series and/or parallel L, C and R's.
Sorry, Bill to speak for you. But I could not resits responding to another Marketing Department (Matthew Polk& Friends, I assume?) claim about "architecture" , where there is none. Such a claim invariably leads to confusion.
Kind regards,
Eelco de Bode
Lol no worries I dont feel attacked, My understanding is/was 2nd order filters made up with inductors, caps, resistors fall into typically 4 catagories of slope profiles LKR, Bessel, Butterworth, Cheybychev and each filter gets its classification to one of those via its Q . And most of the above arrangements appeared to me as having Q's from .8 to 1.1 depending on actual Re of the drivers involved thus placing them in the realms of cheybychev based filter arrangements.
Im not affiliated in any way with polk and ive never seen polk make any claims of the architecture on this xo of this speaker other then a statement of cascading midrange bandpass.
Let me clarify on post 436 about the tweeter. Its got a typical arrangement of a 12db crossover but with a cap value of 9uf in series and a inductor value of .15 mh the calculated Q is from .73@3ohm Re .85@3.5ohm .98@4ohm. So if the drivers inductance stays near 3ohms across its frequencies it would fall into a maximally flat butterworth but if the drivers inductance runs closer to 4ohm at frequencies the Q of the filter rises to near 1Q placing it in theory more near or closer to a cheybychev style of 12db slope on the filtering.
Anyway I think ive got my answer regarding the midrange. One mid sees a 12db hipass from the in series 220uf cap and 1.3mh coil letting only frequecies above x point to the mids, then the other mid sees an addition 6db of hipass pass from the paralleled 68uf cap raising its lp higher then the other mid , thus cascaded, the paralleled 10uf cap between is a 6db lopass to cut the mids off on the upper frequencies. Would i be correct on these assuptions ? Thanks Harlen
Im not affiliated in any way with polk and ive never seen polk make any claims of the architecture on this xo of this speaker other then a statement of cascading midrange bandpass.
Let me clarify on post 436 about the tweeter. Its got a typical arrangement of a 12db crossover but with a cap value of 9uf in series and a inductor value of .15 mh the calculated Q is from .73@3ohm Re .85@3.5ohm .98@4ohm. So if the drivers inductance stays near 3ohms across its frequencies it would fall into a maximally flat butterworth but if the drivers inductance runs closer to 4ohm at frequencies the Q of the filter rises to near 1Q placing it in theory more near or closer to a cheybychev style of 12db slope on the filtering.
Anyway I think ive got my answer regarding the midrange. One mid sees a 12db hipass from the in series 220uf cap and 1.3mh coil letting only frequecies above x point to the mids, then the other mid sees an addition 6db of hipass pass from the paralleled 68uf cap raising its lp higher then the other mid , thus cascaded, the paralleled 10uf cap between is a 6db lopass to cut the mids off on the upper frequencies. Would i be correct on these assuptions ? Thanks Harlen
Suggest use a couple of hours study and set up free REW or ARTA and measure in actual situation those mid drivers impedance curve as zma-file using a simple soundcard I/O loop because then XSim will automatically give you better answers and if you can borrow or get a microphone too it gets even better, for example install REW and open its help file the help for setup is all there.