I am designing a pair of speakers, on a student budget using what I have laying around.
The tweeters are Infinity Emit samarium cobalts from Infinity rs6b circa 1985. They work great and I have always liked them.
The woofers will be Aurasound ns3 8ohm poly cone. (may upgrade to aluminum later)
The cabinet will be 1.5 liters sealed.
I want to make a Linkwitz Riley 4th order @ 4,000hz. Most of the Emits were crossed there. Pretty sure I will avoid cone breakup too. I have almost no information on the Emit, can't find any except for old crossover schematics. In the rs6b's they came from they were crossed with a 4.5mf cap, 0.15mh inductor and 5ohm 5w resistor. http://www.infinity-classics.de/technik/manuals/RS_6B_Specs.pdf
What can I get away with? I don't know much about crossovers and I study science, not engineering so I am a bit ignorant unfortunately.
I will be using an Audyssey MultEQ xt Denon receiver. Therefor can I get away with high passing the tweeter, low passing the woofer and let Audyssey sort out shaping of the frequency response? Do I need to worry about impedance? Audyssey is pretty powerful and can boost by +9db and cut by -20db.
Thanks!
Shawn
The tweeters are Infinity Emit samarium cobalts from Infinity rs6b circa 1985. They work great and I have always liked them.
The woofers will be Aurasound ns3 8ohm poly cone. (may upgrade to aluminum later)
The cabinet will be 1.5 liters sealed.
I want to make a Linkwitz Riley 4th order @ 4,000hz. Most of the Emits were crossed there. Pretty sure I will avoid cone breakup too. I have almost no information on the Emit, can't find any except for old crossover schematics. In the rs6b's they came from they were crossed with a 4.5mf cap, 0.15mh inductor and 5ohm 5w resistor. http://www.infinity-classics.de/technik/manuals/RS_6B_Specs.pdf
What can I get away with? I don't know much about crossovers and I study science, not engineering so I am a bit ignorant unfortunately.
I will be using an Audyssey MultEQ xt Denon receiver. Therefor can I get away with high passing the tweeter, low passing the woofer and let Audyssey sort out shaping of the frequency response? Do I need to worry about impedance? Audyssey is pretty powerful and can boost by +9db and cut by -20db.
Thanks!
Shawn
It is not that easy, overlapping of tweeter and woofer is crucial so there is no substitute for a good crossover. You can start with the EMIT high-pass filter from RS 6/B, add 4.7 ohm resistor parallel to EMIT and maybe you have to substitute 4.5 microF cap with 3.3 microF (if EMIT is too loud). You have to experiment with the low-pass filter for Aura NS3.
Hey thanks for the reply
Could you help me understand a little better? For Linkwitz Riley 4th order it is like two 2nd orders right? I still have to learn how to actually wire them.
Could I get a couple pointers on how to experiment? How do I play around with caps/inductors/resistors and their values?
So my assumption was wrong with Audyssey?, If one driver is louder than the other at any point including approach to the overlap that I should not count on Audyssey to level the differences?
Thanks again
Shawn
Could you help me understand a little better? For Linkwitz Riley 4th order it is like two 2nd orders right? I still have to learn how to actually wire them.
Could I get a couple pointers on how to experiment? How do I play around with caps/inductors/resistors and their values?
So my assumption was wrong with Audyssey?, If one driver is louder than the other at any point including approach to the overlap that I should not count on Audyssey to level the differences?
Thanks again
Shawn
[good] crossover means that the phase at Fc keeps some (+)/(-) limits
so crossover [art] likes the drivers to emit 😱😎 with same phase and...
...equalizers just divide the audio spectrum and regulate the amplitude of each
dunno if PC based multi/active crossovers allow phase to be changed in steps
( depends on bit depth 😕 )
...certainly, passive crossovers introduce phase rotation (electrical ) as also do the ls's ( mechanic )
So...
there are tables...
there are special components made 🙄 to obtain the best
some free thoughts :
The inductor for lowpass introduces a R which is given by Ohm's law
>final Q (t) of the loudspeaker system, but just the bass, so the alignment (...see table: S&T ??! ), is a summation of electrical, mechanical means
>Qe changes
so crossover [art] likes the drivers to emit 😱😎 with same phase and...
...equalizers just divide the audio spectrum and regulate the amplitude of each
dunno if PC based multi/active crossovers allow phase to be changed in steps
( depends on bit depth 😕 )
...certainly, passive crossovers introduce phase rotation (electrical ) as also do the ls's ( mechanic )
So...
there are tables...
there are special components made 🙄 to obtain the best
some free thoughts :
The inductor for lowpass introduces a R which is given by Ohm's law
>final Q (t) of the loudspeaker system, but just the bass, so the alignment (...see table: S&T ??! ), is a summation of electrical, mechanical means
>Qe changes
You don't need to build a passive (electrical) 4th order filter, resulting acoustical order is what is important. Passive 2nd (or 3rd) order filter can provide 4th order LR acoustical filter performance. Passive 2nd order (one inductor and one capacitor) is enough in your case.
Audissey MultEQ XT can level the differences, but it should be the last resort. Proper overlapping of tweeter and midbass driver is of the greatest importance.
Ok, after scratching my head for a few days I feel I can move forward. I will try to make this easy to follow.
Let me describe the project.
My front wall is approx. 500cm wide and 250cm high. I will build a false wall using (4) 125 x 250 cm boards of mdf. They will fit almost perfect. The middle board will have a flush mounted center channel, the boards on each side will have the left and right channels flush mounted and the two far sides will be half size boards with nothing on them.
The drivers will be flush mounted to the baffle wall with cabinets mounted behind. The drivers will not be rigidly mounted to the baffle walls but will be magnet braced to the floor using an abs piped filled with sand and light filler. (floor is also a false floor) The space between the baffle wall and the structural wall will be filled with roxul safe n sound 3 inch rigid insulation. (Same as what's under the floating floor) and the baffle wall is not rigidly attached to the structural walls but is standing on supporting 'feet' (45 degree triangle running the length of the base)
The left and right channels 3 way option is
Tweeter - (1) Emit
Midrange - (1) Aurasound Ns3
Midbass - (1) Aurasound Ns3
Otherwise I will just go 2 way and use 1 NS3 and the Emit. What are your thoughts on these two options? I don't want the midrange to have to deal with the big excursions of this cone and back-wave as it makes it's way down to 80hz.
I have (5) 8ohm NS3 and (5) 4ohm NS3 total for 5.1 surround. Rear channels only need one each.
For the center channel I also have options, I have 2 more Emit tweeters. I may put an Emit tweeter and NS3 below the flush mounted t.v. and the same above, or just an NS3 above or just the Emit and Ns3 below....
For bass I have 2 Seas P21RE drivers, they will be flush mounted in the same walls as the left and right channels, in sealed boxes also using the sand filled abs pipe attached to the magnet and the floor concept. They are driven by a separate 2 channel amp via sub out so the receiver and Audyssey will handle that crossover.
Lets not worry about the surround channels here. You probably have an idea. 😛
Okay now that you have an idea what I am doing please help me fill in the missing pieces!! Should I go 2 way or 3 way with the aurasounds? I am leaning towards 3 way. I really need direct help with the crossovers. Researching other posts and information on the internet is no longer enough.
................................................................
Sonce you mentioned adding a 4.7ohm resistor parallel to the emit, and possibly substitute 4.5mf cap with 3.3mf cap. What does that do?
My thoughts with Audyssey was this. It would be a shame to put resistors in the crossover and waste energy put out by the amplifier, I felt like using Audyssey was the closest I could get to active eq. (my receiver has no pre outs so active eq is not an option currently)
If that is not the way forward then how do I do this?
Thanks to anyone who is helping
Shawn
Let me describe the project.
My front wall is approx. 500cm wide and 250cm high. I will build a false wall using (4) 125 x 250 cm boards of mdf. They will fit almost perfect. The middle board will have a flush mounted center channel, the boards on each side will have the left and right channels flush mounted and the two far sides will be half size boards with nothing on them.
The drivers will be flush mounted to the baffle wall with cabinets mounted behind. The drivers will not be rigidly mounted to the baffle walls but will be magnet braced to the floor using an abs piped filled with sand and light filler. (floor is also a false floor) The space between the baffle wall and the structural wall will be filled with roxul safe n sound 3 inch rigid insulation. (Same as what's under the floating floor) and the baffle wall is not rigidly attached to the structural walls but is standing on supporting 'feet' (45 degree triangle running the length of the base)
The left and right channels 3 way option is
Tweeter - (1) Emit
Midrange - (1) Aurasound Ns3
Midbass - (1) Aurasound Ns3
Otherwise I will just go 2 way and use 1 NS3 and the Emit. What are your thoughts on these two options? I don't want the midrange to have to deal with the big excursions of this cone and back-wave as it makes it's way down to 80hz.
I have (5) 8ohm NS3 and (5) 4ohm NS3 total for 5.1 surround. Rear channels only need one each.
For the center channel I also have options, I have 2 more Emit tweeters. I may put an Emit tweeter and NS3 below the flush mounted t.v. and the same above, or just an NS3 above or just the Emit and Ns3 below....
For bass I have 2 Seas P21RE drivers, they will be flush mounted in the same walls as the left and right channels, in sealed boxes also using the sand filled abs pipe attached to the magnet and the floor concept. They are driven by a separate 2 channel amp via sub out so the receiver and Audyssey will handle that crossover.
Lets not worry about the surround channels here. You probably have an idea. 😛
Okay now that you have an idea what I am doing please help me fill in the missing pieces!! Should I go 2 way or 3 way with the aurasounds? I am leaning towards 3 way. I really need direct help with the crossovers. Researching other posts and information on the internet is no longer enough.
................................................................
Sonce you mentioned adding a 4.7ohm resistor parallel to the emit, and possibly substitute 4.5mf cap with 3.3mf cap. What does that do?
My thoughts with Audyssey was this. It would be a shame to put resistors in the crossover and waste energy put out by the amplifier, I felt like using Audyssey was the closest I could get to active eq. (my receiver has no pre outs so active eq is not an option currently)
If that is not the way forward then how do I do this?
Thanks to anyone who is helping
Shawn
For L and R front I would go 2-way, with 2 Aura NS3 (8-ohm) in parallel. It is a pity that all NS3 are not 8-ohm. So, for the Center loudspeaker use two 4-ohm Aura connected in series.
All loudspeakers must be in the MTM configuration.
No! All drivers must be either below or above TV! For Center, use MTM configuration: one EMIT in the center and two NS3 - one below and one above EMIT.
Aura NS3 has very low efficiency - only 80 dB/1W/1m. EMIT has much higher efficiency, so it needs attenuation to be equally loud as NS3, which is provided by the 4.7 ohm resistor and the smaller capacitor.
Energy going in to the tweeter filter is much, much smaller than the energy going in the midbass. Energy wasted in the resistors is negligible.
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Hey Sonce,
Why do you suggest mtm? I am concerned with peaks, nulls and combing. The EMIT diaphram is large 11.5cm diameter and the crossover is 4k which is an 8.5cm wavelength.
Why do you suggest mtm? I am concerned with peaks, nulls and combing. The EMIT diaphram is large 11.5cm diameter and the crossover is 4k which is an 8.5cm wavelength.
I am suggesting two NS3 in parallel per cabinet (L and R front) because sensitivity of Aura NS3 is very low - only 80 dB/2.83V/1m. With two NS3 (8-ohm) in parallel overall sensitivity is 86 dB/2.83V/1m and maximum power is double. For center loudspeaker, two 4-ohms Auras in series will have 83 dB/2.83V/1m sensitivity and double maximum power.
MMT is much worse than MTM regarding combing.
In Infinity RS 6/b midrange flange diameter is comparable to Aura NS3 diameter and although combing in MTM it is not the same as in MT, MTM configuration will not be so bad after all. Widely spaced NS3 are probably not optimal for such high frequency crossover, but will do as long as EMIT is on the ear height level - easy for front L and R and somewhat more difficult for the center loudspeaker. For center loudspeaker you must mount drivers with different distances from the vertical front panel. For example, if the center loudspeaker is above TV (i.e. above ear height), than mount lower NS3 flat on the vertical panel, EMIT on the spacer about 2 mm from the vertical panel and the top NS3 on the spacer about 4 mm from the vertical panel. Distances 2 mm and 4 mm are only for example, they depends on the distance from the listener and the height above ear level - you do the math.
MMT is much worse than MTM regarding combing.
In Infinity RS 6/b midrange flange diameter is comparable to Aura NS3 diameter and although combing in MTM it is not the same as in MT, MTM configuration will not be so bad after all. Widely spaced NS3 are probably not optimal for such high frequency crossover, but will do as long as EMIT is on the ear height level - easy for front L and R and somewhat more difficult for the center loudspeaker. For center loudspeaker you must mount drivers with different distances from the vertical front panel. For example, if the center loudspeaker is above TV (i.e. above ear height), than mount lower NS3 flat on the vertical panel, EMIT on the spacer about 2 mm from the vertical panel and the top NS3 on the spacer about 4 mm from the vertical panel. Distances 2 mm and 4 mm are only for example, they depends on the distance from the listener and the height above ear level - you do the math.
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Alright Sonce, Makes sense to me.
How do I go about starting building this crossover? Can you give me an explanation as to what it may look like?
Thanks for your help
Shawn
How do I go about starting building this crossover? Can you give me an explanation as to what it may look like?
Thanks for your help
Shawn
Alright Sonce, Makes sense to me.
How do I go about starting building this crossover? Can you give me an explanation what it may look like?
Thanks for your help
Shawn
How do I go about starting building this crossover? Can you give me an explanation what it may look like?
Thanks for your help
Shawn
Low-pass filter: L1=0.33 mH, C1=15 microF, R1=1.5 ohm/10W. Connect R1 and C1 serially, than both of them parallel to two Auras (in parallel) and than L1 serially to the whole bunch.
High-pass filter: C2=3.3 microF, L2=0.15 mH, R2=4.7 ohm.
These values are based on a very crude simulation, because I didn't measure those drivers. For better results - use measuring mic and software.
High-pass filter: C2=3.3 microF, L2=0.15 mH, R2=4.7 ohm.
These values are based on a very crude simulation, because I didn't measure those drivers. For better results - use measuring mic and software.
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