DEQX goodness ordered yesterday and will be with me on Tuesday 🙂 Managed to find a UK dealer with stock:
http://www.tekcare.co.uk/Scripts/prodView.asp?idproduct=77
Not gone for the pre-amp version as I'll be doing multichannel so I'll eventually get round to building something like a 10 way DACT attenuator.
Feel like a sell out now after pimping the PC setup in such a big way. I still think that it holds way more potential than the DEQX could ever hope for but I've spent ££££'s along with 100's maybe 1000's of hours playing around and it hasn't happened.
Nevermind, I hope the DEQX really is the end to my digital crossover journey.
I'll report back with some thoughts and we'll see if it really is worth all that money. One thing is for sure; it had better fix the recent issues I've been having.
http://www.tekcare.co.uk/Scripts/prodView.asp?idproduct=77
Not gone for the pre-amp version as I'll be doing multichannel so I'll eventually get round to building something like a 10 way DACT attenuator.
Feel like a sell out now after pimping the PC setup in such a big way. I still think that it holds way more potential than the DEQX could ever hope for but I've spent ££££'s along with 100's maybe 1000's of hours playing around and it hasn't happened.
Nevermind, I hope the DEQX really is the end to my digital crossover journey.
I'll report back with some thoughts and we'll see if it really is worth all that money. One thing is for sure; it had better fix the recent issues I've been having.
Re: Re: The "Perfect" XO for High End Stereo Systems?!
Hi m0tion,
you investigated the rsult with Excel and observed values in the resulting file in the range +-1.
This is absolutely correct! What you see in the generated file are the real and imaginary parts of the filter response.
In the generated file the first parameter of each line is the frequency, the second the real and the third the imaginary part of the filter response. To get the amplitude of the filter you have to calculate it in your spreadsheet from the real and imaginary part with the following formula:
Amplitude = SQRT (( real*real) + (imaginary*imaginary))
This formula calculates the amplitude of the filter and could be nicely visualized in EXCEL.
I will also provide some examples so stay tuned....
Charly
m0tion said:
Hi m0tion,
you investigated the rsult with Excel and observed values in the resulting file in the range +-1.
This is absolutely correct! What you see in the generated file are the real and imaginary parts of the filter response.
In the generated file the first parameter of each line is the frequency, the second the real and the third the imaginary part of the filter response. To get the amplitude of the filter you have to calculate it in your spreadsheet from the real and imaginary part with the following formula:
Amplitude = SQRT (( real*real) + (imaginary*imaginary))
This formula calculates the amplitude of the filter and could be nicely visualized in EXCEL.
I will also provide some examples so stay tuned....
Charly
Dear Vil,Vil said:
in literature ringing always is described as an irregularity in the time domain and not the frequency domain.
To demonstrate his I took a very steep linear phase Linkwitz Raily filter of 40. order (240db/oct) with a XO-Frequency of 3000Hz and computed the step response for this filter. The red curve is the step response of the LP, the green one the step response if the HP and the blue line is the sum of both of them. I calculated the blue one to show that his filter is phase linear and adds up to a perfect step.
The signals of the LP and the HP start oscillating at 3000Hz long before the step happens. This phenomenon is called preringing and only occurs with linear phase filters (not with minimum phase filters) and is definitely audible. Why?
The blue curve shows that summing up both signals ringing disappears because the ringing of the two signals adds to zero. This is only true adding the electric signals. Firing the ringing signals (red and green) via speakers into your listening room the addition of the wave fronts will be no more perfect so preringing will become audible.
In comparison to the linear phase 40. order LR filter the next image shows the step response of a linear phase 40. order Bessel filter (also 3000Hz) proposed in my paper.
As you see this filter has no ringing at all. You could make the Bessel LP filter as steep as you like. At no circumstance ringing could be observed.
So my advice is to listen carefully before using steep linear phase filters. Caused by preringing often - especially at higher frequencies where the ear is very sensitive - linear phase filters are worse than minimum phase approaches.
By the way, using an IIR filter and calculating it from both sides not really gives any advantage. IIR has no preringing but postringing. Making it phase linear means mirroring the step response so the postringing of the IIR filter will be transformed to an audible preringing! Believe me, nobody could outflank physics ;-))
Charly
What an excellent post oehlrich. I've also now managed to read through the .doc you posted earlier in this thread.
It seems you greatly understand the limits imposed by using linear phase filters. I only wish I had your knowledge and my PC filtering attempts may have been completely successful.
Keep us updated on your progress and I may just give the PC thing another go.
It seems you greatly understand the limits imposed by using linear phase filters. I only wish I had your knowledge and my PC filtering attempts may have been completely successful.
Keep us updated on your progress and I may just give the PC thing another go.
good post oehlrich .
>>in literature ringing always is described as an irregularity in the time domain and not the frequency domain.
sure you are right , I learned that at my college days too , just never used english language terms to describe that , there were no possibility to access any technical books in english language ...
>>in literature ringing always is described as an irregularity in the time domain and not the frequency domain.
sure you are right , I learned that at my college days too , just never used english language terms to describe that , there were no possibility to access any technical books in english language ...
Re: Re: Re: The "Perfect" XO for High End Stereo Systems?!
Don't forget that what you wrote is available for any kind of filter !!!!! There's is always a big difference between theory and speakers reality !
It is well known that 1st order filter are often not so nice in real world, specially off axis !!!!!!
It is just an example !
I use linear phase filter and I offer you a champagne bottle if you can ear the pre ringing on my system !!!! Please come at home !
I've done some blind test, nobody had noticed pre ringing during test, in fact...what is pre ringing for ears in situ ????
In the real life, anyone should consider the benefits of high slopes filters specially off axis. The low speakers interraction offers more goodies than the "pre ringing".
Please notice that the new reference studio monitor made by Focal use linear phase filters (200dB/octave) !!!! and the crossover is at 2.2KHz
I'm not specially a linear phase addict but readers should read carrefully differents point of view...
I still enjoy linear phase filter.... 😀
regards
Marc
Don't forget that what you wrote is available for any kind of filter !!!!! There's is always a big difference between theory and speakers reality !
It is well known that 1st order filter are often not so nice in real world, specially off axis !!!!!!
It is just an example !
I use linear phase filter and I offer you a champagne bottle if you can ear the pre ringing on my system !!!! Please come at home !
I've done some blind test, nobody had noticed pre ringing during test, in fact...what is pre ringing for ears in situ ????
In the real life, anyone should consider the benefits of high slopes filters specially off axis. The low speakers interraction offers more goodies than the "pre ringing".
Please notice that the new reference studio monitor made by Focal use linear phase filters (200dB/octave) !!!! and the crossover is at 2.2KHz
I'm not specially a linear phase addict but readers should read carrefully differents point of view...
I still enjoy linear phase filter.... 😀
regards
Marc
Hi Marc
We all know that linear phase filters can sound great but it is not a trivial task to generate decent linear phase filters. So its more a case of not all filters are equal.
We all know that linear phase filters can sound great but it is not a trivial task to generate decent linear phase filters. So its more a case of not all filters are equal.
BTW DEQX was waiting for me when I arrived home from work.
Just had a *very* quick play and no sign of the distortion I was talking about earlier in the thread. Even when I really crank the volume.
I have to conclude that I do hear pre-echo with DEQX on the really steep filters (300dB/oct. for example) but the problem with the PC was not this. It was more like digital clipping which is completely bizzare as all my level were backed way off when troubleshooting. Something obviously not right in the chain somewhere.
So just to recap; it wasn't pre-echo problems with the PC but something rather different.
No thoughts on just whether or not the DEQX sounds better as I've only tried a highpass on an ATC woofer so far. But I really do like the measurement and setup software for the DEQX, the best I've used yet and offers just as much accuracy and potential in the measurements as the PC did but its way, way fast. I can see it becoming a great tool for future projects.
Just had a *very* quick play and no sign of the distortion I was talking about earlier in the thread. Even when I really crank the volume.
I have to conclude that I do hear pre-echo with DEQX on the really steep filters (300dB/oct. for example) but the problem with the PC was not this. It was more like digital clipping which is completely bizzare as all my level were backed way off when troubleshooting. Something obviously not right in the chain somewhere.
So just to recap; it wasn't pre-echo problems with the PC but something rather different.
No thoughts on just whether or not the DEQX sounds better as I've only tried a highpass on an ATC woofer so far. But I really do like the measurement and setup software for the DEQX, the best I've used yet and offers just as much accuracy and potential in the measurements as the PC did but its way, way fast. I can see it becoming a great tool for future projects.
I have followed your journey with interest. No doubt, you'll get the bug to go back to the PC at some point afte you've got everything decently sorted and have actually had a chance to enjoy music for a while. But since I have a DEQX coming in the next week or so, I'm selfishly glad that you have one in hand. Bad for you (timewise), good for us that you will be out ahead of the curve, especially with what you've already learned so far. Expect plenty of questions, if you are game.
Sheldon
Sheldon
Re: Re: Re: Re: The "Perfect" XO for High End Stereo Systems?!
You are right if you say steep filters have advantages. One of the advantages is (as I wrote!) that the lobbing error (this is what you call ‘off axis’) is minimal. The other big advantage is that the frequency ranges where the driver may be far away from its perfect linear operation are just switched off by the brickwall filters. These two advantages were paid by ringing and time delay.
Reading my paper you should have seen that the proposed Bessel filter has a wider overlapping region but in this very special case the softer slope did NOT create any lobing error. So here I can see no advance using a brickwall filter.
Looking at the 2. order slope of the HP I wrote that the response of the driver may pollute the response of the filter. This means applying a 2. order XO alone would not be sufficient. The driver also has to be corrected in such a way, that the convolution of driver-, correction- and XO response exactly covers the slope of the XO. Using brickwall filters and omitting driver correction creates a smaller error than using a 2. order slope without correction. Despite of this omitting driver correction always leads to errors. So I recommend to perform driver correction in any way (I plan to write about that).
Next point is ringing. I guess there is no discussion: Preringing is audible if it extends a certain degree. I admit that the point when it is audible strongly depends on the drivers used and how perfect the wavefront of both drivers add in space. The Bessel filter I proposed has no ringing at all.
Regarding delay the Bessel filter is perfect because it could be realized as minimum phase OR linear phase filer. Both of them share the same transient perfect response and also have the same perfect polar response. Just use whatever you like!
I did not state that the proposed Bessel filter is the best one could do! I just tried to show the pros and cons of the different approaches and summarized that the Bessel filer aggregates more pros than cons which makes it a good candidate for a XO.
If you have a PC based system, just give it a try and listen!
Charly
Dear Marc,mbon said:
You are right if you say steep filters have advantages. One of the advantages is (as I wrote!) that the lobbing error (this is what you call ‘off axis’) is minimal. The other big advantage is that the frequency ranges where the driver may be far away from its perfect linear operation are just switched off by the brickwall filters. These two advantages were paid by ringing and time delay.
Reading my paper you should have seen that the proposed Bessel filter has a wider overlapping region but in this very special case the softer slope did NOT create any lobing error. So here I can see no advance using a brickwall filter.
Looking at the 2. order slope of the HP I wrote that the response of the driver may pollute the response of the filter. This means applying a 2. order XO alone would not be sufficient. The driver also has to be corrected in such a way, that the convolution of driver-, correction- and XO response exactly covers the slope of the XO. Using brickwall filters and omitting driver correction creates a smaller error than using a 2. order slope without correction. Despite of this omitting driver correction always leads to errors. So I recommend to perform driver correction in any way (I plan to write about that).
Next point is ringing. I guess there is no discussion: Preringing is audible if it extends a certain degree. I admit that the point when it is audible strongly depends on the drivers used and how perfect the wavefront of both drivers add in space. The Bessel filter I proposed has no ringing at all.
Regarding delay the Bessel filter is perfect because it could be realized as minimum phase OR linear phase filer. Both of them share the same transient perfect response and also have the same perfect polar response. Just use whatever you like!
I did not state that the proposed Bessel filter is the best one could do! I just tried to show the pros and cons of the different approaches and summarized that the Bessel filer aggregates more pros than cons which makes it a good candidate for a XO.
If you have a PC based system, just give it a try and listen!
Charly
Re: Re: Re: Re: Re: The "Perfect" XO for High End Stereo Systems?!
yes, I have a PC based system with an ESI wamirack 192x with eight balanced output. I also used a DCX2496 for a long time (out of box version)
I've done many many crossover experiments. Like you I want to give pros and cons and IMHO pre ringing is not audible if time alignment of speakers is perfect wich can be done "easily" with an impulse measurement. As you wrote it depends of drivers, of course if you use a very slow midrange and a very fast tweeter like Heil EMT ribbon, first order may work better...for sure !
I'm only speaking of a "good" loudspeaker design wich of course mean that drivers match the best possible.
Please note that ShinOBIWAN still not ear "ringing" effect with his new DEQX...but... what is "pre ringing" for ears ?
It should be fun to burn a CD with a WAV including this effect !!!!
IMHO, each crossover type include some artefacts, I don't want to write that linear phase (with or without high slope) are perfect !
*-delay is an issue if playing video, for music it is not.
*-digital crossover means complex installation with lot of power amp and cables
*-electrical sum of HP and LP from brickwall filters is not flat, you should use different cutoff frequencies for both LP and HP wich bring little hole or little bump at crossover frequencie, well done it should never exceed 0.5dB but if you don't care you can get a +3dB à crossover freq.
At the moment, I've the orion from linkwitz and my TAD drivers, it would be fun to burn such a pre ringing effect and play on Orions !!!!
ShinOBIWAN : it seems you experiment some clipping or jitter trouble or empty buffer or bad latency. I use very basic PC P4 3 Ghz 1Go RAM, only Win XP, native sound processor with Ozone running in 192Khz and no more...no bug, no crash, I've never had any troubles ! Please tell us the DEQX sounding, I'd also like to have such an nice engine but I would prefer the preamp version !
Hello Charly !
yes, I have a PC based system with an ESI wamirack 192x with eight balanced output. I also used a DCX2496 for a long time (out of box version)
I've done many many crossover experiments. Like you I want to give pros and cons and IMHO pre ringing is not audible if time alignment of speakers is perfect wich can be done "easily" with an impulse measurement. As you wrote it depends of drivers, of course if you use a very slow midrange and a very fast tweeter like Heil EMT ribbon, first order may work better...for sure !
I'm only speaking of a "good" loudspeaker design wich of course mean that drivers match the best possible.
Please note that ShinOBIWAN still not ear "ringing" effect with his new DEQX...but... what is "pre ringing" for ears ?
It should be fun to burn a CD with a WAV including this effect !!!!
IMHO, each crossover type include some artefacts, I don't want to write that linear phase (with or without high slope) are perfect !
*-delay is an issue if playing video, for music it is not.
*-digital crossover means complex installation with lot of power amp and cables
*-electrical sum of HP and LP from brickwall filters is not flat, you should use different cutoff frequencies for both LP and HP wich bring little hole or little bump at crossover frequencie, well done it should never exceed 0.5dB but if you don't care you can get a +3dB à crossover freq.
At the moment, I've the orion from linkwitz and my TAD drivers, it would be fun to burn such a pre ringing effect and play on Orions !!!!
ShinOBIWAN : it seems you experiment some clipping or jitter trouble or empty buffer or bad latency. I use very basic PC P4 3 Ghz 1Go RAM, only Win XP, native sound processor with Ozone running in 192Khz and no more...no bug, no crash, I've never had any troubles ! Please tell us the DEQX sounding, I'd also like to have such an nice engine but I would prefer the preamp version !
as I mention in my last post, one way to check what is preringing is to hear the electric sum of LP and HP with some crossover.
I've done the test right now !!!!
I've recorded 3 shorts WAV of a french artist :
-one wich is the bypass recording
-one wich is the sum of high and low section with a 440 Hz FIR crossover
-one wich is the sum of high and low section with a 2200 Hz FIR crossover
Please note that I've put a little different crossover freq between HP and LP to limit the bump of sum but for the 2200 sample I'm not sure that it is efficient, LP is @ 2197 and @2200Hz, in fact I'm sure that the 2200 Hz sample has a little bump @2.2K but this small artefact don't worry me in a living room. Listening it with headphone may give a different result...
I go right to my headphone !!!!!
I've listened them on the Orion and...hum hum..no comments ! 😀
sample is the left channel mixed as mono on left and right.
If someone want to try, I can send them by mail in the "private" domain, I don't want to post some wav on public forum do to copyright....
If someone can ear and describe the preringing effect, let's discuss about it !!!!!
I've done the test right now !!!!
I've recorded 3 shorts WAV of a french artist :
-one wich is the bypass recording
-one wich is the sum of high and low section with a 440 Hz FIR crossover
-one wich is the sum of high and low section with a 2200 Hz FIR crossover
Please note that I've put a little different crossover freq between HP and LP to limit the bump of sum but for the 2200 sample I'm not sure that it is efficient, LP is @ 2197 and @2200Hz, in fact I'm sure that the 2200 Hz sample has a little bump @2.2K but this small artefact don't worry me in a living room. Listening it with headphone may give a different result...
I go right to my headphone !!!!!
I've listened them on the Orion and...hum hum..no comments ! 😀
sample is the left channel mixed as mono on left and right.
If someone want to try, I can send them by mail in the "private" domain, I don't want to post some wav on public forum do to copyright....
If someone can ear and describe the preringing effect, let's discuss about it !!!!!
Marc,
Can you tell us a bit more about your setup?
I understand you use a PC digital crossover for the Orion?
What is the software used?
What are the parameters of the filters?
What are the differences in terms of sound between this crossover and the original one?
I have just started building a pair of Orion and I am interested in the digital crossover approach. I already use a PC as the source for my music.
Thanks
Can you tell us a bit more about your setup?
I understand you use a PC digital crossover for the Orion?
What is the software used?
What are the parameters of the filters?
What are the differences in terms of sound between this crossover and the original one?
I have just started building a pair of Orion and I am interested in the digital crossover approach. I already use a PC as the source for my music.
Thanks
J'utilise le filtre actif de linkwitz car ces orions sont en prêt chez moi, j'ai mesuré une très bonne réponse en fréquence. C'est une solution très simple à utiliser, rentrer ce type de filtre dans le PC demande une sérieuse motivation que je n'ai pas pour le moment !Saam said:
Et puis j'ai un problème de gain, si je met ma carte son directe sur les amplis des orions je vais avoir trop de volume, c'est le frein principal !
Preringing
Hi Marc
I like to come back to that ringing theme. You ask for a WAV to hear ringing. I guess it is impossible to produce it the way you propose it. Why?
Looking at the step response of a 40th order linear phase LR FIR filter I recently posted you could see the red an the green curve. The red curve is the signal your bass driver receives from the filter, the green one the signal the tweeter receives.
Listening to the tweeter only (without the bass) or the bass only (without the tweeter) ringing should be audible. To hear it you best produce a signal with a sequence of short pulses (pulse length of e.g 0.3ms). The pulses should repeat at a frequency of 140 Hz or lower. Listening to this signal by the tweeter without bass you should hear the ringing frequency of about 2000Hz.
To demonstrate the signal the tweeter gets behind a 2 kHz 40th order linear phase LR filter I made a calculation for you.
The green curve is the pulse (0.3ms) at the input of the HP filter the blue curve is the signal the tweeter transmits into your listening room.
In any case in the real world - if the drivers (bass and tweeter) are perfectly time aligned - the ringing will be compensated and no more audible there you’re right. As you know time alignment is perfect at one point only and then only at a single elevation angle (assuming vertically displaced drivers). So outside the perfect time aligned listening position the ringing of the individual filters is an issue!
In comparison to the HP output of the 40th order linear phase LR HP at 2000Hz I calculated the response of the HP derived from a linear phase Bessel LP of 40th order also at 2000Hz.
As you see there is no ringing at all. So also outside the perfect time aligned listening position no ringing could be audible.
I must admit that I have not made a WAV of both responses till now to make a listening test against each other. If you are interested please let me know. I could do that and publish the WAV files.
By the way …..
The Orions are really excellent speakers. Linkwitz perfectly realized the open baffle principle. During my last summer holiday I copied his whole website and carefully read through this material. Any thing was quite profound! After this I had a mail conversation with him regarding his filters because he uses LR filters which are not transient perfect.
He approved what I have read elsewhere about the effect of transient perfect filters in the bass region. He said a transient perfect XO for the bass may probably further improve the quality of the ORION. So just calculate a transient perfect filter for the bass XO of the Orions and listen if this would be better than LR. Would be a very interesting experiment ;-))
I also run an open baffle system. Heard it on the High End 2005 and made a rebuild of it. It really sounds great! I believe that the open baffle principle is one of the best!
http://www.audioelevation.de/messe_high_end_2005.htm
Charly
Hi Marc
I like to come back to that ringing theme. You ask for a WAV to hear ringing. I guess it is impossible to produce it the way you propose it. Why?
Looking at the step response of a 40th order linear phase LR FIR filter I recently posted you could see the red an the green curve. The red curve is the signal your bass driver receives from the filter, the green one the signal the tweeter receives.
Listening to the tweeter only (without the bass) or the bass only (without the tweeter) ringing should be audible. To hear it you best produce a signal with a sequence of short pulses (pulse length of e.g 0.3ms). The pulses should repeat at a frequency of 140 Hz or lower. Listening to this signal by the tweeter without bass you should hear the ringing frequency of about 2000Hz.
To demonstrate the signal the tweeter gets behind a 2 kHz 40th order linear phase LR filter I made a calculation for you.
The green curve is the pulse (0.3ms) at the input of the HP filter the blue curve is the signal the tweeter transmits into your listening room.
In any case in the real world - if the drivers (bass and tweeter) are perfectly time aligned - the ringing will be compensated and no more audible there you’re right. As you know time alignment is perfect at one point only and then only at a single elevation angle (assuming vertically displaced drivers). So outside the perfect time aligned listening position the ringing of the individual filters is an issue!
In comparison to the HP output of the 40th order linear phase LR HP at 2000Hz I calculated the response of the HP derived from a linear phase Bessel LP of 40th order also at 2000Hz.
As you see there is no ringing at all. So also outside the perfect time aligned listening position no ringing could be audible.
I must admit that I have not made a WAV of both responses till now to make a listening test against each other. If you are interested please let me know. I could do that and publish the WAV files.
By the way …..
The Orions are really excellent speakers. Linkwitz perfectly realized the open baffle principle. During my last summer holiday I copied his whole website and carefully read through this material. Any thing was quite profound! After this I had a mail conversation with him regarding his filters because he uses LR filters which are not transient perfect.
He approved what I have read elsewhere about the effect of transient perfect filters in the bass region. He said a transient perfect XO for the bass may probably further improve the quality of the ORION. So just calculate a transient perfect filter for the bass XO of the Orions and listen if this would be better than LR. Would be a very interesting experiment ;-))
I also run an open baffle system. Heard it on the High End 2005 and made a rebuild of it. It really sounds great! I believe that the open baffle principle is one of the best!
http://www.audioelevation.de/messe_high_end_2005.htm
Charly
Part II: Driver Time Alignment
Well,
this is the second part of my story.
The theme is 'Driver Time Alignment' and I hope this paper would be useful for you or inspire you for some good discussions ;-))
http://freerider.dyndns.org/anlage/MyDrc/Driver-Time-Alignment.zip
Charly
Well,
this is the second part of my story.
The theme is 'Driver Time Alignment' and I hope this paper would be useful for you or inspire you for some good discussions ;-))
http://freerider.dyndns.org/anlage/MyDrc/Driver-Time-Alignment.zip
Charly
Re: Preringing
I've made the wav, the summation include the ringing effect why ?
If you record a sine sweep from 20 to 20000 Hz and its summation using linear phase filter with high slope, you obtain the impulse response by convolution and the pre écho "ringing" effect is QUITE visible, so IT IS RECORDED and if this effect is audible, you should hear it !
If I just calculate I can demonstrate that there is strong phase rotation using IIR filters and say that is audible. I don"t do that because I've enjoyed a lot of speakers using analog filters from first to fourth order. It's not always an issue !!!!
If you listen at a tweeter with a 2.2K cutoff, you will experience lots of artefact with any kind of filters, I've done a lot of tests in this way with both DCX and PC, listening at one speakers is interresting but not for crossovers, only the summation is important.
Yes, S.L. is a great guy, Orion is a great design. S.L. believe that distorsion phase is not audible, jean michel le cleach believe it is audible. It depends of so many things that only the global results is important, there is always some compromise, we just choose them...
I will make a detailed review of Orions after two weeks of listening test.
To review a system I need to live with for a month ! It's the same for crossovers !
A challenge for me is to switch from S.L. active filter to the linear phase version of ASP using full DSP ! He told me that it will be a hard work and I believe it !
Measurement of an OB system is not easy.
My review will compare to my reference system wich is high efficiency using TAD drivers...
For the moment I already have a big problem...My 15" TAD drivers are feed by a Crown K1 (2x250W)....and both 10" XLS drivers from Orions has.....a rotel 40W power amp......
I would like to experiment a 1000W power amp on bass drivers of Orions but Siegfried told me that it should damage drivers due to XMax limit.
Ultra low sensitivity in OB is an maybe an issue...
I've made the wav, the summation include the ringing effect why ?
If you record a sine sweep from 20 to 20000 Hz and its summation using linear phase filter with high slope, you obtain the impulse response by convolution and the pre écho "ringing" effect is QUITE visible, so IT IS RECORDED and if this effect is audible, you should hear it !
Charly...please stop calculting to demonstrate it is audible, you just demonstrate it exists ! Just demonstrate by listening tests before claming pre ringing is audible ! Do you have the softwares to apply linear phase filter ? please do it and listen !
If I just calculate I can demonstrate that there is strong phase rotation using IIR filters and say that is audible. I don"t do that because I've enjoyed a lot of speakers using analog filters from first to fourth order. It's not always an issue !!!!
If you listen at a tweeter with a 2.2K cutoff, you will experience lots of artefact with any kind of filters, I've done a lot of tests in this way with both DCX and PC, listening at one speakers is interresting but not for crossovers, only the summation is important.
Yes, S.L. is a great guy, Orion is a great design. S.L. believe that distorsion phase is not audible, jean michel le cleach believe it is audible. It depends of so many things that only the global results is important, there is always some compromise, we just choose them...
I will make a detailed review of Orions after two weeks of listening test.
To review a system I need to live with for a month ! It's the same for crossovers !
A challenge for me is to switch from S.L. active filter to the linear phase version of ASP using full DSP ! He told me that it will be a hard work and I believe it !
Measurement of an OB system is not easy.
My review will compare to my reference system wich is high efficiency using TAD drivers...
For the moment I already have a big problem...My 15" TAD drivers are feed by a Crown K1 (2x250W)....and both 10" XLS drivers from Orions has.....a rotel 40W power amp......
I would like to experiment a 1000W power amp on bass drivers of Orions but Siegfried told me that it should damage drivers due to XMax limit.
Ultra low sensitivity in OB is an maybe an issue...
The best method I know to check time alignment is to measure impulse response of the system and then analyse the spectral view of this, you can have in one shot the delay between your drivers and most interresting, it allow you to view the group delay.
When I was tuning my crossover between horn and bass drivers, the group delay that horn get into its lowest frequencies is quite visible, then I try to time align the bass at the crossover frequency as shown below, another choice is to align bass on trebbles, measurement still use behringer ECM8000, a PC sound card with I/O, cooledit or adobe audition and the plugin Aurora wich help to get impulse response by convolution, dirac is another way but IMHO not so comfortable and accurate :
When I was tuning my crossover between horn and bass drivers, the group delay that horn get into its lowest frequencies is quite visible, then I try to time align the bass at the crossover frequency as shown below, another choice is to align bass on trebbles, measurement still use behringer ECM8000, a PC sound card with I/O, cooledit or adobe audition and the plugin Aurora wich help to get impulse response by convolution, dirac is another way but IMHO not so comfortable and accurate :
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