Can anyone help my determine what is best for my speakers as far as if I should crossover, high pass or just go full range? I have all the specs and can post links if this is something that sounds doable?
Thanks in advance.
Thanks in advance.
Thanks AllennB
Below are the links to the speakers and xo I purchased back in 2006. I built the cabinets myself using a speaker cabinet calculator back in 2006 and I see now in 2021 Eminence has a cabinet spec .pdf which looks real close to the cabinet cubic feet I have for vented large type cabinet.
Anyway back in 2006 the Eminence pxb2 1600 Hz xo did not seem to workout for me and the system I built sounded horrible. The HF drivers were way to loud compared to my 12LFs and the 12 LFs seemed to cut out in the mid range. The speakers and HF drivers are all 8 ohm. I am using them for 6 string electric classic rock guitar sound. I am powering the speaker cabinets with a Peavey XR 696 Power Mixer with dual power amps that when combined with 8 ohm speakers has 360 watt RMS output to each speaker output. However, I never pushed it to 360 watts. So, I put it all in storage as I had other more important projects at that time. am now trying to go back and fix this mess 14 years later. Everything looks solid as the storage was temperature controlled.
I have disconnected the pbx2 1600 Hz xo and hooked up the 12LFs to run full range to see what it sounded like. It certainly sounds way better than it did before but does not have the HF glistening sounds I want to highlight my pic scrapes, harmonic pick squeals, and fingers gliding along the fret-board when I do my slides.
So I wait to hear your advise on my set up and I am hoping that running the 12LFs full range combined with a high pass filter for my HF drivers is going to work. The question is what will work best?
I am pretty dumb about acoustics but I know a lot about electronics. I cannot find a schematic of the Eminence pxb2 1600 Hz crossover. However, it is a low pass 2nd order Butterworth combined with a high pass 3rd order Butterworth. The exception is the that high pass part of the circuit starts with 2 filaments prior to the air core inductor and
2 caps part of the circuit. I also measured the air core inductor ( not the same design as the link photo). My air core inductor is 0.8 inch long with a 0.74 inch air core and has 17 gauge wire. Looking at my air core inductor's measurements it seems to fit what is required of 0.6 mH inductor for 1600 Hz high pass 3rd order Butterworth with a little more than 17 turns per level which fits with the DIY Audio Guide Air Core Inductor calculator provided by this forum. The reason why I have analyzed my existing xo like this is because if the best fit high pass frequency is higher than 1600 Hz (which I suspect it is) then potentially I could remove some of the turns and replace the caps on my pbx2 and modify it to be a higher frequency high pass filter unless you know of reasons to not do that? I don't know. I have a lot ideas but last time my ideas did not work at all and that is why I am asking for help.
The 12LF
https://www.eminence.com/pdf/Delta_12LFA.pdf
My HF Drivers
https://img.musicworld.bg/pdf/i/0/1/4/6410/DH 200E Manual.pdf
My crossover but the links on this are certainly not much help to understand the actual circuit.
Eminence PXB2:1K6 2-Way Speaker Crossover Board 1,600 Hz
Thank you for taking at look at all of this. I really appreciate any help at all.
Below are the links to the speakers and xo I purchased back in 2006. I built the cabinets myself using a speaker cabinet calculator back in 2006 and I see now in 2021 Eminence has a cabinet spec .pdf which looks real close to the cabinet cubic feet I have for vented large type cabinet.
Anyway back in 2006 the Eminence pxb2 1600 Hz xo did not seem to workout for me and the system I built sounded horrible. The HF drivers were way to loud compared to my 12LFs and the 12 LFs seemed to cut out in the mid range. The speakers and HF drivers are all 8 ohm. I am using them for 6 string electric classic rock guitar sound. I am powering the speaker cabinets with a Peavey XR 696 Power Mixer with dual power amps that when combined with 8 ohm speakers has 360 watt RMS output to each speaker output. However, I never pushed it to 360 watts. So, I put it all in storage as I had other more important projects at that time. am now trying to go back and fix this mess 14 years later. Everything looks solid as the storage was temperature controlled.
I have disconnected the pbx2 1600 Hz xo and hooked up the 12LFs to run full range to see what it sounded like. It certainly sounds way better than it did before but does not have the HF glistening sounds I want to highlight my pic scrapes, harmonic pick squeals, and fingers gliding along the fret-board when I do my slides.
So I wait to hear your advise on my set up and I am hoping that running the 12LFs full range combined with a high pass filter for my HF drivers is going to work. The question is what will work best?
I am pretty dumb about acoustics but I know a lot about electronics. I cannot find a schematic of the Eminence pxb2 1600 Hz crossover. However, it is a low pass 2nd order Butterworth combined with a high pass 3rd order Butterworth. The exception is the that high pass part of the circuit starts with 2 filaments prior to the air core inductor and
2 caps part of the circuit. I also measured the air core inductor ( not the same design as the link photo). My air core inductor is 0.8 inch long with a 0.74 inch air core and has 17 gauge wire. Looking at my air core inductor's measurements it seems to fit what is required of 0.6 mH inductor for 1600 Hz high pass 3rd order Butterworth with a little more than 17 turns per level which fits with the DIY Audio Guide Air Core Inductor calculator provided by this forum. The reason why I have analyzed my existing xo like this is because if the best fit high pass frequency is higher than 1600 Hz (which I suspect it is) then potentially I could remove some of the turns and replace the caps on my pbx2 and modify it to be a higher frequency high pass filter unless you know of reasons to not do that? I don't know. I have a lot ideas but last time my ideas did not work at all and that is why I am asking for help.
The 12LF
https://www.eminence.com/pdf/Delta_12LFA.pdf
My HF Drivers
https://img.musicworld.bg/pdf/i/0/1/4/6410/DH 200E Manual.pdf
My crossover but the links on this are certainly not much help to understand the actual circuit.
Eminence PXB2:1K6 2-Way Speaker Crossover Board 1,600 Hz
Thank you for taking at look at all of this. I really appreciate any help at all.
I posted my situation and data but I get a message that says a moderator needs to review it. Does this forum block links to Eminence and Selenium speaker data .pdfs?
Edit never mind
Edit never mind
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not sure it matters but my 2006 data sheet is somewhat different than the link I provided of the 2021 12LF. The most significant difference is that my 2006 data shows Resonant Frequency (fs) to be 45 Hz and the 2021 data sheet shows 51 Hz.
My data also show minor differences in the Thiele=Small Parameters. However, my 2006 data coil impedance, magnet weight, Xmax and speaker dimensions are the same as the 2021 data so the major components have not changed.
My data also show minor differences in the Thiele=Small Parameters. However, my 2006 data coil impedance, magnet weight, Xmax and speaker dimensions are the same as the 2021 data so the major components have not changed.
Your links are fine. The thing you didn't do when you first did this was to make an L-pad for the tweeter.
AllenB,
I was wondering about attenuation. The tungsten filaments that exist on my pbx2 1600 Hz xo are supposed to be "positive temperature coefficient series varistors" that "smoothly compress the HF current level up to 3:1 analog compression during input overload conditions over 250Wrms". That is quote straight out of my pbx2 data sheet from 2006.
I had thought that this compression should be plenty to tame down my HF drivers. However, I have to admit that I do not fully understand the function of the varistor in this case as an analog compressor.
Obviously it is not what I was thinking. Or not as much as I need.
Now that I am a little older I am looking back at the frequency response curves comparison and I feel like a deer in the headlights. FYI Eminence did not have a response curve for the 12LFs in the cabinets in 2006. The curve of my HF drivers dB output appears to output a lot more than the 12LFs in the large vented cabinet. Maybe that is why I was getting a big jump to the HF driver and some kind of phase shift cutting the 12LFs when pushing out a lot of midrange using high gain distortion guitar effects. The HF drivers would run anyone out of the room.
So you think 1600 Hz is a good xo point? Would it hurt to change the xo to 2500 Hz?
If I do an L Pad how can I determine the correct R1 and R2? I am really lost on that part.
How about this link for variable L Pad pot?
Eminence PX-LPAD Crossover L-Pad Attenuator
Parts express has member participation and they said the L pad pot would work for my set up if putting it after a high pass of 2500 Hz but my confidence is sort of shaky on this. That's why I am asking DIY Audio forum members.
If a pot will work it would be nice to find something that is not so pricey and I have not a clue about the specs for a pot that would fit the load that I am putting out.
Thanks for all you help.
I was wondering about attenuation. The tungsten filaments that exist on my pbx2 1600 Hz xo are supposed to be "positive temperature coefficient series varistors" that "smoothly compress the HF current level up to 3:1 analog compression during input overload conditions over 250Wrms". That is quote straight out of my pbx2 data sheet from 2006.
I had thought that this compression should be plenty to tame down my HF drivers. However, I have to admit that I do not fully understand the function of the varistor in this case as an analog compressor.
Obviously it is not what I was thinking. Or not as much as I need.
Now that I am a little older I am looking back at the frequency response curves comparison and I feel like a deer in the headlights. FYI Eminence did not have a response curve for the 12LFs in the cabinets in 2006. The curve of my HF drivers dB output appears to output a lot more than the 12LFs in the large vented cabinet. Maybe that is why I was getting a big jump to the HF driver and some kind of phase shift cutting the 12LFs when pushing out a lot of midrange using high gain distortion guitar effects. The HF drivers would run anyone out of the room.
So you think 1600 Hz is a good xo point? Would it hurt to change the xo to 2500 Hz?
If I do an L Pad how can I determine the correct R1 and R2? I am really lost on that part.
How about this link for variable L Pad pot?
Eminence PX-LPAD Crossover L-Pad Attenuator
Parts express has member participation and they said the L pad pot would work for my set up if putting it after a high pass of 2500 Hz but my confidence is sort of shaky on this. That's why I am asking DIY Audio forum members.
If a pot will work it would be nice to find something that is not so pricey and I have not a clue about the specs for a pot that would fit the load that I am putting out.
Thanks for all you help.
This tungsten varistor, which may simply be a light bulb, is not really supposed to do anything unless you increase output.
Yes, your off the shelf crossover will be less than optimum but can be used as a starting point if it's all you have.
1600Hz is near the highest I would choose to use a 12" driver. The next piece of that puzzle is finding the right horn to go with it.
The L-pad is not only essential to bring the tweeter level down, but it helps the crossover to work better with the tweeter. The variable one would be a good start, then you could replace it with a pair of resistors. You could buy just one for testing purposes, then measure it and buy real resistors. Other methods include measuring and guessing.
Yes, your off the shelf crossover will be less than optimum but can be used as a starting point if it's all you have.
1600Hz is near the highest I would choose to use a 12" driver. The next piece of that puzzle is finding the right horn to go with it.
The L-pad is not only essential to bring the tweeter level down, but it helps the crossover to work better with the tweeter. The variable one would be a good start, then you could replace it with a pair of resistors. You could buy just one for testing purposes, then measure it and buy real resistors. Other methods include measuring and guessing.
Yes Allen. I agree. They look like light bulbs or a fuse.
My choice of HF driver and crossover could have been better but I should be able to modify and get it to give me what I am looking for. I am up for some experimenting anyway.
As you were making your reply I was thinking the same thing you were saying. I don't want a variable pot in the end because pots go bad all the time. Dust etc. Especially with 50 to 100 watt running through the pot.
It looks to me like I need the L pad wired in after the xo. I got that part now.
I found the formulas for L pad and maybe this will help me find a pot for experimenting that is less than $24 plus shipping LOL!
I am thinking 100 watt resistors.
I also just read that Eminence suggest a 35Hz steep high pass filter on the 12LFs to protect from over excursion. I am thinking a first order high pass for that but not until I get everything else working right.
I also just read that if I am having phase shift trouble to reverse polarity on the HF driver and if better then leave it that way.
Thank you. You have helped get on a path to fix this problem.
My choice of HF driver and crossover could have been better but I should be able to modify and get it to give me what I am looking for. I am up for some experimenting anyway.
As you were making your reply I was thinking the same thing you were saying. I don't want a variable pot in the end because pots go bad all the time. Dust etc. Especially with 50 to 100 watt running through the pot.
It looks to me like I need the L pad wired in after the xo. I got that part now.
I found the formulas for L pad and maybe this will help me find a pot for experimenting that is less than $24 plus shipping LOL!
I am thinking 100 watt resistors.
I also just read that Eminence suggest a 35Hz steep high pass filter on the 12LFs to protect from over excursion. I am thinking a first order high pass for that but not until I get everything else working right.
I also just read that if I am having phase shift trouble to reverse polarity on the HF driver and if better then leave it that way.
Thank you. You have helped get on a path to fix this problem.
You didn't make a bad choice on the HF driver because of this level issue, it's not uncommon.
100W, probably not. Most of the time these things run in the milliWatts, even if it takes a bit more to get the woofer going.
High pass on the 12"? You're not using these in a club, are you?
Phase, well what you've said will get you started. Once you have these functioning we can talk about doing it better.
100W, probably not. Most of the time these things run in the milliWatts, even if it takes a bit more to get the woofer going.
High pass on the 12"? You're not using these in a club, are you?
Phase, well what you've said will get you started. Once you have these functioning we can talk about doing it better.
PXB1K6 IIRC uses a 2nd order lowpass:1.2mH/10uF and generic 3rd order Butterworth highpass: 8uF/0.8mH/24uF highpass.
The paralleled 211 lamps can be helpful as a soft limited.
If your horn/driver combo has a significant impedance peak in the 1-2KHz ragne then I'd suppose the interaction could bring the horn down to 1200Hz.
Does you horn have a relatively long and expanding throat ("neck") ? - or is it a "constant directivity" type? If the latter then the horn response will fall off after 3KHZ and the pad needs to be contoured with a capacitor bypassing a series resistor. (see "Econowave" for info)
Also, some 1" compression drivers just don't sound good with that low of crossover. Oddly enough I've had no uglyness from 1" format tweeters with that board using a "K-tube". Which tells me you might try that approach. It could even be tested with a rolled paper tube about 5.5" long with a half ellipse cased slot cut with scissors.
You can pretty easily change components on those boards even with their hardboard backing. - woret case would be to snip out a cap leaving some lead to solder in a new - diffrrent
The paralleled 211 lamps can be helpful as a soft limited.
If your horn/driver combo has a significant impedance peak in the 1-2KHz ragne then I'd suppose the interaction could bring the horn down to 1200Hz.
Does you horn have a relatively long and expanding throat ("neck") ? - or is it a "constant directivity" type? If the latter then the horn response will fall off after 3KHZ and the pad needs to be contoured with a capacitor bypassing a series resistor. (see "Econowave" for info)
Also, some 1" compression drivers just don't sound good with that low of crossover. Oddly enough I've had no uglyness from 1" format tweeters with that board using a "K-tube". Which tells me you might try that approach. It could even be tested with a rolled paper tube about 5.5" long with a half ellipse cased slot cut with scissors.
You can pretty easily change components on those boards even with their hardboard backing. - woret case would be to snip out a cap leaving some lead to solder in a new - diffrrent
Crossovers can be big, heavy and expensive so I always go for none.
My disco speaker cabinet is a pair of Fane 12-250TC (triple cones) to get a half decent full range.
My disco speaker cabinet is a pair of Fane 12-250TC (triple cones) to get a half decent full range.
What does it mean on this forum to "trim quotes" and why?
I am reading a lot of material that I never considered before. I assumed to many things 14 years ago. It really takes a lot reading and working with this stuff to understand it all. It looks like I also messed up sizing my speaker's rms power more than my amp's rms power. I just read last night that the rule of thumb is 2:1 or 1.5:1 amp:speaker.
nigelwrite7557 >>>I hear you but I already am committed to fix what I have and there are limits to my budget right now unless I sell off some of my other equipment.
freddi>>> The caps that you list for the pbx1K6 are the same ones on my pbx2-1K6 so I will assume that the inductors that you list are the same as mine too. Yes it is 2nd order LP with 3rd order HP. My Horn is a Selenium HC23-25 with a DH200E driver. The plastic horn section is 127 mm plus another 18 mm that the inner baffle that protrudes out into the room. The data sheet states it is a "Compact Size". Yes the curve on my 2006 data sheet shows 2 big impedance spikes between 1K and 2K. There is also about a 5dB response drop at 3K. I don't know what you mean "bring the horn down to 1200Hz"???? I know a fair sum about electronics but I am totally speaker/acoustics dumb. I am learning. I will look into the "Ecconowave" and try to better understand the capacitor for the pad that you speak of since there is drop after 3K. I don't know what K tube is but I'll see if I can find out.
AllenB>>>what watt resistors for L pad would you experiment with considering my power situation? No I am not playing in clubs anymore. I just saw that the 12LF driver can be high passed just one more thing I missed 14 years ago. I am 60 years now and two new grandchildren this year. I just recovered from neck/spine surgery and so my wife cannot schedule as much work for me anymore LOL!. That is why I now have time go back and fix these speakers. I just picked up my guitar last month for the first time in 12 years.
Thanks everyone for helping me.
I am reading a lot of material that I never considered before. I assumed to many things 14 years ago. It really takes a lot reading and working with this stuff to understand it all. It looks like I also messed up sizing my speaker's rms power more than my amp's rms power. I just read last night that the rule of thumb is 2:1 or 1.5:1 amp:speaker.
nigelwrite7557 >>>I hear you but I already am committed to fix what I have and there are limits to my budget right now unless I sell off some of my other equipment.
freddi>>> The caps that you list for the pbx1K6 are the same ones on my pbx2-1K6 so I will assume that the inductors that you list are the same as mine too. Yes it is 2nd order LP with 3rd order HP. My Horn is a Selenium HC23-25 with a DH200E driver. The plastic horn section is 127 mm plus another 18 mm that the inner baffle that protrudes out into the room. The data sheet states it is a "Compact Size". Yes the curve on my 2006 data sheet shows 2 big impedance spikes between 1K and 2K. There is also about a 5dB response drop at 3K. I don't know what you mean "bring the horn down to 1200Hz"???? I know a fair sum about electronics but I am totally speaker/acoustics dumb. I am learning. I will look into the "Ecconowave" and try to better understand the capacitor for the pad that you speak of since there is drop after 3K. I don't know what K tube is but I'll see if I can find out.
AllenB>>>what watt resistors for L pad would you experiment with considering my power situation? No I am not playing in clubs anymore. I just saw that the 12LF driver can be high passed just one more thing I missed 14 years ago. I am 60 years now and two new grandchildren this year. I just recovered from neck/spine surgery and so my wife cannot schedule as much work for me anymore LOL!. That is why I now have time go back and fix these speakers. I just picked up my guitar last month for the first time in 12 years.
Thanks everyone for helping me.
^ Right here I have deleted everything in your last post except this question. If we didn't do that we'd all get repetitive strain injury from all the scrolling which isn't actually necessary.
With regards to the resistors, it varies.. so I'd suggest you keep a stash of 5W resistors (different values), and from time to time feel them to see whether they are handling the heat.
Cool. That helps reduce the strain on my neck too.
The 5W resistors got it. The power is so much less than what I thought. I could have saved some money on speakers had I known what I know now.
We have Gateway Electronics here in St. Louis County MO so I will make trip to their store tomorrow and stock up on supplies for this project.
Thank you.
Just opened up a Costco sized bag of popcorn, and settled in for the continuation of the show that never ends.
a capacitor's reactance can interact with an impedance peak to cause a downwards shift in corner frequency. That can be useful with "3rd order" sealed boxes to extend the low end.
Your horn (and its PRV relative) make nice on-axis graphs so are self-EQ-ing ("beaming") on axis vs the constant directivity type.
I assume you tried both wiring polarities with your tweeter horn ? - that can make a lot of difference.
Here's an example of a sealed bot behavior when a capacitor is added in series
https://i.imgur.com/xXWABj7.png
Your horn (and its PRV relative) make nice on-axis graphs so are self-EQ-ing ("beaming") on axis vs the constant directivity type.
I assume you tried both wiring polarities with your tweeter horn ? - that can make a lot of difference.
Here's an example of a sealed bot behavior when a capacitor is added in series
https://i.imgur.com/xXWABj7.png
My cabinets incorporate an isolation baffle for the HF driver which is sealed. The LF driver is port vented with a 4" ID PVC pipe 3-13/16" length. I have an old floppy disc with my own EXCEL speaker cabinet volume calculator stored on it as well as the the clacs I used to make these cabinets. However, I no longer have a PC with floppy drive so and I can not remember exactly what I did in 2006.
I do understand the PRV Polar Response Vector concepts and "beaming" after just now reading up on Karllson Tubes and other waveguide options. Thanks for the read on that. At one time I stuffed a rag in the horns but that did not work either. Certainly was not beaming with the rag in it. I know just from being a musician certain acoustic principles; like horns having a series of resonant frequency nodes and harmonics similar to string instruments in many ways. I have a few violins with some made prior to 1850 where musical instrument makers set the resonant frequency during the Baroque period to middle A and as such the Classical Period is marked by musical instrument makers changing the resonant frequency to middle C. The way the vents and ports and structures are all made have unique effects on the sound that the instruments create as well as speakers cabinets and HF horns. So, I do have some experience with the fundamentals.
I am not sure I would try the K Tube if just out of experimenting but that paper cut out version might be a good test to keep in mind.
I am pretty sure that I won't need a bypass cap in this situation but I will keep it in mind as I am doing my L pad experiments. I work in the potable water supply industry I understand this in a very simple way. Like a water tank that is used to absorb some portion of surge pressure. Except the bypass capacitor focuses on a specific envelope (frequency range) providing a route and temporary storage area for the unwanted signal other than the speaker.
I have not tried to reverse the polarity on the HF driver. I think I will make that my first experiment.
Thank you. I really appreciate your help and introducing me to new and interesting options.
My second test was to reconnect the crossovers with standard polarity. I assumed that my problem from 2006 did not go away by putting my speakers in storage. So, right out of the start line my first 2021 test I bypassed the crossover in early August to try full range on the 12 LFs which sounded OK but not with the highs I like. Anyway, that is why I started this thread with the title Full Range or Crossover.
After I hooked both xo with standard polarity I played maybe 20 classic rock songs from my I tunes library real loud and there was no phasing, cutting or anything like what happened back in 2006. So it looks like standard polarity is good. The sound quality was too much HF with all my EQ on my Peavey Amp at 0dB. So I increased the EQ according to my liking on the LF end about 15 dB boost overall and I cut the HF about 12 dB overall. I got the sound to be really good. The only issues were no headroom left on my LF EQ range and the Peavey Amp has to be maxed out to get the drivers to the point where everyone on my street is pissed off. The reason why is because my amp is not enough for these speakers not anything wrong with the speakers. One thing I like about my Peavey Amp is the DDT Clip Eliminator. I can pretty much run the amp a full output power and not get any clipping indicators glaring at me. I did not get that far in 2006 so it is nice to finally play around with this amp which has maybe 15 hours on it even though it is 14 years old.
I don't know for sure what happened in 2006. The midrange cutting or phasing in 2006 certainly had nothing to do with the xo. I did rewire my guitar back in 2006 to run my 2 single coil pickups out of phase. The midrange cutting or phasing had to be my guitar...there is no other option. So I did some research on pickup wiring and found nothing specific related to speaker midrange problems but I did find out that my pickups are not reverse wound with respect to each other and pickup magnets are all south facing the strings. According to what I have read nobody wires guitars pickups out of phase unless they have reverse wound reverse magnetic pickups. What I suspect was the problem in 2006 is that my guitar was driving the speakers out of phase with respect to the other guitars in our band when we all picked/plucked our strings on q at the same pick strike.
Anyway full range does not sound as good as the crossover. I have been doing Lpad testing and I will get a reply going to AllenB on that. Thank you for your help.
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