Can I sneak in here? I've been trying to get help with adding a single notch filter to the midrange bandpass section of this xover. I have great difficulty even posting pictures, as I am not very computer literate. This is the circuit as it stands, I want to add the filter before the level pot (VR2) if possible. xover_3way_2_ - My Photo Gallery The ICs and filter caps are numbered oddly because some some sections have been removed or moved .
Would a section of the ESP circuit work, and how would I modify it to fit? I have looked at the Linkwitz and ESP pages, and just get a headache!
This is a working xover, so I am pretty much stuck with this circuit.
Would a section of the ESP circuit work, and how would I modify it to fit? I have looked at the Linkwitz and ESP pages, and just get a headache!
This is a working xover, so I am pretty much stuck with this circuit.
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This is what it actually looks like. At the moment I am only using it as a 2 way, but you can see the mid bandpass board without any caps or opamps. The small boards on the sides are for baffle step comp.http://i1134.photobucket.com/albums/m604/awkwardbydesign/oracleparts011.jpg
it ought to be possible, with minor changes
its all filters, and more or less similar
but your xo curcuit board will need some traces cut, and a few added wires
got away from it now, but I know its in there, somewhere 😀
if you look at one of the ESP subwoofer filter designs, you will see that each parametric EQ curcuit is very similar to the xo filters
Parametric and Sub-Woofer Equaliser
but I dont think its a constant Q
so the frequency function will generally be wider, and 'milder' effect
but who knows, it might actually sound better that way
for very deep narrow notch you would need controlled Q
Parametric and Sub-Woofer Equaliser
but I dont think its a constant Q
so the frequency function will generally be wider, and 'milder' effect
but who knows, it might actually sound better that way
for very deep narrow notch you would need controlled Q
Attachments
now, I wasnt planning to use notches, which might be slightly different 
I only had rather simple attenuation controls in mind
hell, even a simple Baxandall might have some positive effect
but wouldnt have the variable frequency sweep, and thus more 'fixed'
I only had rather simple attenuation controls in mind
hell, even a simple Baxandall might have some positive effect
but wouldnt have the variable frequency sweep, and thus more 'fixed'
Did you mean me? My xover was designed by Ben Duncan, and published in HiFi News in 1981, with later updates. The filter caps ratios in the mid section are to Linkwitz's specs, I think. The treble and bass ratios are to the original Ben Duncan spec, as they were already in use, but the mid section is a new build, so I incorporated the updates in there.
for a midrange driver you would need two controls, one for the lows, and one for highs
but thats kind of the advantage with this particular subject
which is why I suggested the Baxandall
all the eq controls would ofcourse have to be seperated curcuits, and not like usually done when sharing the same center frequency
whats the big deal ?
well, the speciality would be that the eq controls interferes with each xo slope seperately
placed before the xo, or after ? hard to say, but why not have both now we are at it 😀
Hi,
I haven't created an EQ, but if you would like a circuit for a state variable filter capable of matching the acoustic response of speakers to a L-R4 alignment this circuit should be able to do it.
It allows independent adjustment of the centre frequency and Q of each of a cascade of 2 x 2nd order state variable filters. So if you had perfect drivers you could adjust it to two Butterworth filters and have a perfect L-R4 alignment.
More importantly if you haven't got perfect speakers you can independently adjust the Q and centre frequency so you can create an acoustic response that matches an L-R4 alignment; including offset slopes or centre frequencies to adjust for time alignment between the Mid and tweeter.
Is this the sort of thing you are looking for? I have created LTspice simulatable circuits but I have not actually built it. Your welcome to the files if you want to play and see what it does. It does have a the notch output identified in the state variable filter so I think you could create elliptic alignments if you wanted to. (I haven't tried this)
If you did build this you will need some form of measurement system as there are too many variables to be able to set this up by ear. I was planning to use it to allow me to quickly evaluate different driver combinations but then the economy tanked and I lost my job in audio so it never went any further.
Regards,
Andrew
I haven't created an EQ, but if you would like a circuit for a state variable filter capable of matching the acoustic response of speakers to a L-R4 alignment this circuit should be able to do it.
It allows independent adjustment of the centre frequency and Q of each of a cascade of 2 x 2nd order state variable filters. So if you had perfect drivers you could adjust it to two Butterworth filters and have a perfect L-R4 alignment.
More importantly if you haven't got perfect speakers you can independently adjust the Q and centre frequency so you can create an acoustic response that matches an L-R4 alignment; including offset slopes or centre frequencies to adjust for time alignment between the Mid and tweeter.
Is this the sort of thing you are looking for? I have created LTspice simulatable circuits but I have not actually built it. Your welcome to the files if you want to play and see what it does. It does have a the notch output identified in the state variable filter so I think you could create elliptic alignments if you wanted to. (I haven't tried this)
If you did build this you will need some form of measurement system as there are too many variables to be able to set this up by ear. I was planning to use it to allow me to quickly evaluate different driver combinations but then the economy tanked and I lost my job in audio so it never went any further.
Regards,
Andrew
Thanks Andrew, sorry you lost your job - hope you get something soon if you haven't already. That looks like exactly what I was after.
I ended up with switchable 2nd order crossovers and basically just played with the switches and gains until I couldn't hear a difference when I swept a sine wave through the crossover frequency. Very crude but ended up with a nice sound. Just checked what I ended up with and the HF unit (1" dome) crosses over at 3750Hz and the LF unit (12" twin cone) at 9750Hz. This sounds like it shouldn't work, but does. I avoided 4th order because of the complexity of setting up, but will bookmark this for if and when I can get hold of some measuring equipment as you suggested.
Brian.
I ended up with switchable 2nd order crossovers and basically just played with the switches and gains until I couldn't hear a difference when I swept a sine wave through the crossover frequency. Very crude but ended up with a nice sound. Just checked what I ended up with and the HF unit (1" dome) crosses over at 3750Hz and the LF unit (12" twin cone) at 9750Hz. This sounds like it shouldn't work, but does. I avoided 4th order because of the complexity of setting up, but will bookmark this for if and when I can get hold of some measuring equipment as you suggested.
Brian.
Sorry, just check my calculations, and it should read 3kHz for the HF, and 6.6kHz for the LF.
Brian
Brian
Hi Brian, Thanks for the support, It was 2008 when I lost my job and I found a new one in environmental science within my notice period. Saving the world is all well and good but I do miss audio sometimes 🙂 skills transferred surprisingly well but I have had to brush up on science.
Would you like the LT spice files?
Regards,
Andrew
Would you like the LT spice files?
Regards,
Andrew
Hi Andrew, glad you got sorted, I remember when I was made redundant, with a pregnant wife, mortgage etc. all a bit stressful, but strangely interesting too...
Yes please to the LT spice files, not sure when I would get time to build it, but one day I hope to spend a bit more time on this.
Thanks,
Brian.
Yes please to the LT spice files, not sure when I would get time to build it, but one day I hope to spend a bit more time on this.
Thanks,
Brian.
I might have it figured out now
12db filter and a baxandall tone control with its centre placed at xo 'point'
on low pass filter you will be able to influence rolloff with 'tweeter' attenuation
only bass control works in the passband
on high pass filter its the other way round
time will tell if it works at all
12db filter and a baxandall tone control with its centre placed at xo 'point'
on low pass filter you will be able to influence rolloff with 'tweeter' attenuation
only bass control works in the passband
on high pass filter its the other way round
time will tell if it works at all
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