Here you can download the schematic and a calculation program for such a highpass including buffer:
Active High Pass Filter
What Jörg wants you to do is described in this famous paper by Mr. Keele:
http://www.xlrtechs.com/dbkeele.com/PDF/Keele (1975-07 AES Published) - New Set of VB Alignments.pdf
There are lots of other interesting papers to be found on that site BTW.
Regards
Charles
Active High Pass Filter
What Jörg wants you to do is described in this famous paper by Mr. Keele:
http://www.xlrtechs.com/dbkeele.com/PDF/Keele (1975-07 AES Published) - New Set of VB Alignments.pdf
There are lots of other interesting papers to be found on that site BTW.
Regards
Charles
Would it not be possible to make the active high pass filter with software like Foobar if Audiomig is using any such thing?
If Foobar can do IIR filters - then yes. A 2nd order highpass with the proper pole frequnecy and Q value would do.
Regards
Charles
Regards
Charles
Hello altogether ,
here are the Files as jpeg.
It was not possible to share the EAGLE-Files (sorry they had not the right data Format to post them...)
Burgunder & Phase_accurate woke up my interest fot Foolbar. What is it?
And to Calculate an active (Sallen-Key) Filter i am a littel bit old-school - I take my Book "Tietze & Schenk -Halbleiter Schaltungstechnik" and a simple Excel-sheet.
Regards Jörg.
here are the Files as jpeg.
It was not possible to share the EAGLE-Files (sorry they had not the right data Format to post them...)
Burgunder & Phase_accurate woke up my interest fot Foolbar. What is it?
And to Calculate an active (Sallen-Key) Filter i am a littel bit old-school - I take my Book "Tietze & Schenk -Halbleiter Schaltungstechnik" and a simple Excel-sheet.
Regards Jörg.
Attachments
Foobar is a digital player for PC that has a lot of possibilities foobar2000
Then you could do the filter in software, which seems preferable if you use a pc as player.
Then you could do the filter in software, which seems preferable if you use a pc as player.
Plan your work... Work your plan. Best results with lowest cost and disappointment.
12xa30nd........12xa30nd.........12xa30nd
The 12xa30nd 12" midbass with Qts=0.21 using a 1.2-1.6Khz Xover will get the best sound in a sealed, well stuffed box. A large box volume can be reduced by adding wood blocks if some transient tuning experiments are desired. These interior dimensions provide space for 2" of absorption material on 3-walls. Qtc=0.7 tuning is typically not considered optimal for a Qts=0.21 speaker. Golden ratio: 1 x 1.618 x 0.618
14"W x 22.6"L x 8.7"D = 2753 in^3 = 1.58cuft - 0.6cuft for speaker+ bracing+port walls = 1cuft
port = 3"Dia 3"Long 63hz
SEALED = Qtc~0.58 100Hz
15"W x 24"L x 10"D = 3900 in^3 = 2.08cuft - 0.6cuft for speaker+ bracing+port walls = 1.5cuft
port = 3"Dia 2"Long, 55hz... -3db bass-shelf
SEALED = Qtc~0.5 87Hz
WOOFERS: 30Hz at 100db SPL with 20 watts of power
==== Sd ====
18" 1220 cm2
15" 855 cm2
12" 530 cm2
10" 345 cm2
8" 225 cm2
The large cone area of an 18" woofer provides high efficiency bass with modest distortion generating displacement. Side-to-Side physically connected woofer pairs use counter-forces to dramatically reduce vibrations. Two 18" woofers can provide high quality room-equalized bass from a sealed box alignment with modest watts. Two 18" woofers like (Faital 18FH500, Peavey 479910 LoRider18, Beyma 18LX60 rev1) which have modest Mms (140-180g) and Qts~ 0.37 connected in parallel in a sealed 9cuft volume can provide Qtc=0.7 alignment with F3=60Hz before equaliztion extends the bass to the 20-30Hz range... 30Hz at 100db SPL with 20 watts of power.
12xa30nd........12xa30nd.........12xa30nd
The 12xa30nd 12" midbass with Qts=0.21 using a 1.2-1.6Khz Xover will get the best sound in a sealed, well stuffed box. A large box volume can be reduced by adding wood blocks if some transient tuning experiments are desired. These interior dimensions provide space for 2" of absorption material on 3-walls. Qtc=0.7 tuning is typically not considered optimal for a Qts=0.21 speaker. Golden ratio: 1 x 1.618 x 0.618
14"W x 22.6"L x 8.7"D = 2753 in^3 = 1.58cuft - 0.6cuft for speaker+ bracing+port walls = 1cuft
port = 3"Dia 3"Long 63hz
SEALED = Qtc~0.58 100Hz
15"W x 24"L x 10"D = 3900 in^3 = 2.08cuft - 0.6cuft for speaker+ bracing+port walls = 1.5cuft
port = 3"Dia 2"Long, 55hz... -3db bass-shelf
SEALED = Qtc~0.5 87Hz
WOOFERS: 30Hz at 100db SPL with 20 watts of power
==== Sd ====
18" 1220 cm2
15" 855 cm2
12" 530 cm2
10" 345 cm2
8" 225 cm2
The large cone area of an 18" woofer provides high efficiency bass with modest distortion generating displacement. Side-to-Side physically connected woofer pairs use counter-forces to dramatically reduce vibrations. Two 18" woofers can provide high quality room-equalized bass from a sealed box alignment with modest watts. Two 18" woofers like (Faital 18FH500, Peavey 479910 LoRider18, Beyma 18LX60 rev1) which have modest Mms (140-180g) and Qts~ 0.37 connected in parallel in a sealed 9cuft volume can provide Qtc=0.7 alignment with F3=60Hz before equaliztion extends the bass to the 20-30Hz range... 30Hz at 100db SPL with 20 watts of power.
Attachments
^^I agree 100%, the 12XA maintains low distortion and excellent transient response when restricted above 100Hz and in a small box (or OB). With just 10 watts of power it will fill a large room. Partner with a similar high-efficiency woofer 15" unit (or four, like the Emerald Physics CS 2.7) with a high bias Class AAB solid-state amplifier and enjoy the results.
Don't push it into uncomfortable territory as you will not be happy with the end result and not know how to fix it. I've learnt this the very hard way 🙂 Start with the right plan. The 12XA will have audible and nasty IMD when asked to do bass. It is not comfortable in spite of what the sims tell you.
If you do want a speaker that does it all, then look at the RCF drivers, I belive those can do some semblance of bass. However, all of these units from the lowly Beta 12 to the very top end are PA main drivers, which in pro speak translates to no bass duty at all. Quite oddly though, the Beta 12 itself, being the cheapest of all of these types, does passable and enjoyable bass to a degree in a ported box of 100L, but even then below 50Hz is totally absent.
Don't push it into uncomfortable territory as you will not be happy with the end result and not know how to fix it. I've learnt this the very hard way 🙂 Start with the right plan. The 12XA will have audible and nasty IMD when asked to do bass. It is not comfortable in spite of what the sims tell you.
If you do want a speaker that does it all, then look at the RCF drivers, I belive those can do some semblance of bass. However, all of these units from the lowly Beta 12 to the very top end are PA main drivers, which in pro speak translates to no bass duty at all. Quite oddly though, the Beta 12 itself, being the cheapest of all of these types, does passable and enjoyable bass to a degree in a ported box of 100L, but even then below 50Hz is totally absent.
Hi
Thank you for all the posts!
Linesource, you mention F3=60hz before equalization, 20-30hz with equalization.
Is this equalization done in the xover?
Can it be a passive xover or does it need to be and active filter like Jorg suggested?
Or is it a subwoofer with xover and amplification in the box, like this for example: Strassacker: Loudspeakerkits (DIY kits)
Thank you for all the posts!
Linesource, you mention F3=60hz before equalization, 20-30hz with equalization.
Is this equalization done in the xover?
Can it be a passive xover or does it need to be and active filter like Jorg suggested?
Or is it a subwoofer with xover and amplification in the box, like this for example: Strassacker: Loudspeakerkits (DIY kits)
Useful Questions:
How much analog source material do you have? (Vinyl, magnetic tape, FM radio)
Are you comfortable with adding a second amp just for the woofer(under 120HZ)? This amp+xover can have enough flexibility to work with several future TM tops and listening rooms. Solid state or 50W tube.
=======================
If you run a tool like "Room Response Calculator by Yavuz Aksan" and simulate the best speaker and best seating locations for your listening room, you will observe the large variations in bass SPL, plus wall reflections affecting upper frequencies.
===
If you want to use only ONE medium power tube amplifier to power both the 12xa30Nd and ??-woofer you will need to build a LARGE horn woofer box and build a complex passive bass Xover to "modestly" flatten the bass SPL room response.
If you are open to using an analog active filter + crossover like Jorg/Linkwitz discuss you can boost the low-freq bass and also smooth the major room gain effect with a modest size bass box. You will need a second amp. opamp Xover tutorial Active Filters
If you are open to using a digital active equalization filter + crossover you can achieve very flat bass SPL. You will need a second amp, which works with the digital filter, which works with your front end electronics.
How much analog source material do you have? (Vinyl, magnetic tape, FM radio)
Are you comfortable with adding a second amp just for the woofer(under 120HZ)? This amp+xover can have enough flexibility to work with several future TM tops and listening rooms. Solid state or 50W tube.
=======================
If you run a tool like "Room Response Calculator by Yavuz Aksan" and simulate the best speaker and best seating locations for your listening room, you will observe the large variations in bass SPL, plus wall reflections affecting upper frequencies.
===
If you want to use only ONE medium power tube amplifier to power both the 12xa30Nd and ??-woofer you will need to build a LARGE horn woofer box and build a complex passive bass Xover to "modestly" flatten the bass SPL room response.
If you are open to using an analog active filter + crossover like Jorg/Linkwitz discuss you can boost the low-freq bass and also smooth the major room gain effect with a modest size bass box. You will need a second amp. opamp Xover tutorial Active Filters
If you are open to using a digital active equalization filter + crossover you can achieve very flat bass SPL. You will need a second amp, which works with the digital filter, which works with your front end electronics.
Attachments
Hi to all!
Mostly I like to hear vinyl (+/-1000), I also have plenty of CDs (>1000).
I think, after reading all your inputs, that the best option looks definitely to have the beyma in a closed box and amplified bass, a subwoofer under each monitor basically.
I would like to leave the top box fully analogue (no digitalization/DSP).
The sub would then be DSP equalized.
I am thinking to run the monitor full range and connect it through the speakers terminal to the subwoofer (high level connection).
Can somebody suggest a subwoofer amplifier(s) that has speaker inputs (high level) and DSP so that I can correct the response of the bass in the room?
What do you all think about this plan?
Meanwhile I am going to start working on the monitor box.
Rgs
Mostly I like to hear vinyl (+/-1000), I also have plenty of CDs (>1000).
I think, after reading all your inputs, that the best option looks definitely to have the beyma in a closed box and amplified bass, a subwoofer under each monitor basically.
I would like to leave the top box fully analogue (no digitalization/DSP).
The sub would then be DSP equalized.
I am thinking to run the monitor full range and connect it through the speakers terminal to the subwoofer (high level connection).
Can somebody suggest a subwoofer amplifier(s) that has speaker inputs (high level) and DSP so that I can correct the response of the bass in the room?
What do you all think about this plan?
Meanwhile I am going to start working on the monitor box.
Rgs
I am planning to go with this configuration (as suggested by LineSource):
38,1cm x 61cmL x 25,4cmD = 59L – 17L =42L
15"W x 24"L x 10"D = 2.08cuft - 0.6cuft for speaker+ bracing+port walls = 1.5cuft
SEALED = Qtc~0.5 87Hz
Is it a good choice ? 🙂
38,1cm x 61cmL x 25,4cmD = 59L – 17L =42L
15"W x 24"L x 10"D = 2.08cuft - 0.6cuft for speaker+ bracing+port walls = 1.5cuft
SEALED = Qtc~0.5 87Hz
Is it a good choice ? 🙂
Hi Jorg,
I think I will try your box as well:
36cmW x 46cmH x 29cmD = 48L - 17L (bracing+speaker) = 31L
Port: 70mm Diam, Port Lenght is 91mm.
Active Highpass-Filter based on the filter you have supplied.
Let's see how this will come out ...
I think I will try your box as well:
36cmW x 46cmH x 29cmD = 48L - 17L (bracing+speaker) = 31L
Port: 70mm Diam, Port Lenght is 91mm.
Active Highpass-Filter based on the filter you have supplied.
Let's see how this will come out ...