Hi
I'm considering purchasing a pair of the orginal Apogee Full Range's. In my mind they're like the ultimate speaker so, really should get em
However the passive crossover boxes with transformers are missing.
There seem to be plenty knowledgable apogee owners on this forum so I'm hoping someone can verify what I've found so far:
- The bass ribbons originally had a step-up transformer but are just 1.7 ohms so I could drive them direct?
- The midrange is below 0.1 ohms so obviously needs a step-up transformer (assuming I dont want to burn 95% of amp power in series resistors)
- Crossovers were just 1st order, for high pass on midrange and tweeters there were series capacitors in the passive crossover boxes but what about Low pass? I dont see any series coils employed on old pictures, I think I see some caps in the original active crossover boxes though, parallel caps then before the amps (not quite sure how that would work)?
My current line of thought is:
-Get step up transformers for the midrange ribbons
-Get 6 channels of amplification (thinking hypex class-D modules for now, already have 2 of those)
-Series caps for high pass for mid/high amps, low pass series coils or? Parallel caps + resistors?
The dutch ribbon replacement installer has some step up transformers (3 ohm primary) but says those make the mids play 15 dB's louder then the rest, sounds a bit odd, not sure how that works?? He also has transformers for the tweeters but I dont see why I would want to use them in that position, should be ~2 ohms so no problem for direct drive?
Hope someone can shed some light on this.
Some pictures of the corssovers I found on the allmighty internet:
I'm considering purchasing a pair of the orginal Apogee Full Range's. In my mind they're like the ultimate speaker so, really should get em
However the passive crossover boxes with transformers are missing.There seem to be plenty knowledgable apogee owners on this forum so I'm hoping someone can verify what I've found so far:
- The bass ribbons originally had a step-up transformer but are just 1.7 ohms so I could drive them direct?
- The midrange is below 0.1 ohms so obviously needs a step-up transformer (assuming I dont want to burn 95% of amp power in series resistors)
- Crossovers were just 1st order, for high pass on midrange and tweeters there were series capacitors in the passive crossover boxes but what about Low pass? I dont see any series coils employed on old pictures, I think I see some caps in the original active crossover boxes though, parallel caps then before the amps (not quite sure how that would work)?
My current line of thought is:
-Get step up transformers for the midrange ribbons
-Get 6 channels of amplification (thinking hypex class-D modules for now, already have 2 of those)
-Series caps for high pass for mid/high amps, low pass series coils or? Parallel caps + resistors?
The dutch ribbon replacement installer has some step up transformers (3 ohm primary) but says those make the mids play 15 dB's louder then the rest, sounds a bit odd, not sure how that works?? He also has transformers for the tweeters but I dont see why I would want to use them in that position, should be ~2 ohms so no problem for direct drive?
Hope someone can shed some light on this.
Some pictures of the corssovers I found on the allmighty internet:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
http://www.apogeespeakers.com/.............i gess you saw this...crossover is in the manul
you can down lode.......bewair of the Apogee panel Buzz!...theses are the oldest... i think?... I have Had the Stages an the Duetta Sig....
Good luck
you can down lode.......bewair of the Apogee panel Buzz!...theses are the oldest... i think?... I have Had the Stages an the Duetta Sig....
Good luck
Hmm thanks, this version has a last page with schematics of the active crossover
So that has series caps for mf/hf highpass and parallel caps for lf lowpass. 1 step further..So only things I need to figure out if there's a midrange lowpass in the passive box and what kind of transformer I need for the midrange.
Oh and I've read both 3.5K as 9K for the hf highpass?
Apogee Acoustics • Index page
Go here ... If you havet.... i think your calling a coil, a tranfourmer...anywho...these guys well help you with this.....good luck
Go here ... If you havet.... i think your calling a coil, a tranfourmer...anywho...these guys well help you with this.....good luck
Hi edbk,
We have a pair of Apogee Full Range Speakers in our living room. They came with the 4-ohm network box.
Over the Full Range production lifetime Apogee made a few minor changes to the construction of the Bass Panel, midrange ribbon, and tweeter ribbon which affected their resistance, efficiency, and resonance.
MY SPEAKERS:
Bass Panel = 1.86 ohms
Midrange Ribbon = 0.14 ohms
Tweeter Ribbon = 0.88 ohms
Original passive front-end crossover box is 6db at 320Hz between the bass panel and mid-tweet ribbons.
=================
You will want to measure your speakers before you build a custom crossover, or decide to clone a production circuit. Bi-Amping (bass + mid-tweet) using an active circuit crossover is a good starting option. The low efficiency 1.9 ohm bass panel can easily consume 300-1000 watts.
The midrange ribbon step-up transformer that you build or purchase will be the cornerstone specification for the rest of the passive or active crossover design. The turns ratio will set the impedance step-up. The inductance of the production midrange step-up transformer input is actually part of the low-pass crossover slope. The inductance of any transformer you purchase will need to be measured and factored into the total crossover design. This step-up transformer will set the midrange ribbon efficiency and effective amplifier input inpedance load. The ribbon impedance is almost pure resistance, and this simplifies the design of a passive crossover between the MID-TWEET ribbons.
Apogee also offered a 1-ohm network box for JUST the midrange+tweeter ribbons. This box included a 0.14-to-1 ohm step-up transformer for the midrange ribbon, plus R+C crossover network for the tweeter ribbon. There is potential for sonic improvements with this 1-ohm network box vs. the 4-ohm network box, but only if the amplifier can deliver HUGE amperes into 1-ohm like the BIG Krells.
Naturally, constructing a custom Bipolar amplifier that can drive 0.2 or 0.5 ohm resistive ribbon loads directly is another option, and not very difficult. From my listening experiments, adding a small series resistance to increase the 0.14 ohm midrange ribbon up to 0.2-0.5 ohms improved the sonics.
=================
My Speakers...
Each 3-way Full Range is bi-amped with one Krell KSA250 located just behind the speaker. A Krell KRX-1 electronic crossover with 18db/octave at 200Hz is used for for bass-MT outputs to each amp. One KSA250 channel direct drives the 2 ohm bass panel, and the second channel drives Apogee's M-T interface box which is ~4 ohms. This interface box contains a large toroidal step up transformer for the 0.14 ohm M-ribbon, plus resistors to step up the tweeter ribbon resistance to ~4 ohms, plus a 6db/octave passive L + C Xover at 10Khz. This is a very robust setup for the Full Range.
I have built DIY amps which direct drive the 0.1 ohm midrange ribbon and 2 ohm tweeter ribbons. Direct drive always produces greater dynamics and detail, but it is also easier to damage a ribbon by human error.
We have a pair of Apogee Full Range Speakers in our living room. They came with the 4-ohm network box.
Over the Full Range production lifetime Apogee made a few minor changes to the construction of the Bass Panel, midrange ribbon, and tweeter ribbon which affected their resistance, efficiency, and resonance.
MY SPEAKERS:
Bass Panel = 1.86 ohms
Midrange Ribbon = 0.14 ohms
Tweeter Ribbon = 0.88 ohms
Original passive front-end crossover box is 6db at 320Hz between the bass panel and mid-tweet ribbons.
=================
You will want to measure your speakers before you build a custom crossover, or decide to clone a production circuit. Bi-Amping (bass + mid-tweet) using an active circuit crossover is a good starting option. The low efficiency 1.9 ohm bass panel can easily consume 300-1000 watts.
The midrange ribbon step-up transformer that you build or purchase will be the cornerstone specification for the rest of the passive or active crossover design. The turns ratio will set the impedance step-up. The inductance of the production midrange step-up transformer input is actually part of the low-pass crossover slope. The inductance of any transformer you purchase will need to be measured and factored into the total crossover design. This step-up transformer will set the midrange ribbon efficiency and effective amplifier input inpedance load. The ribbon impedance is almost pure resistance, and this simplifies the design of a passive crossover between the MID-TWEET ribbons.
Apogee also offered a 1-ohm network box for JUST the midrange+tweeter ribbons. This box included a 0.14-to-1 ohm step-up transformer for the midrange ribbon, plus R+C crossover network for the tweeter ribbon. There is potential for sonic improvements with this 1-ohm network box vs. the 4-ohm network box, but only if the amplifier can deliver HUGE amperes into 1-ohm like the BIG Krells.
Naturally, constructing a custom Bipolar amplifier that can drive 0.2 or 0.5 ohm resistive ribbon loads directly is another option, and not very difficult. From my listening experiments, adding a small series resistance to increase the 0.14 ohm midrange ribbon up to 0.2-0.5 ohms improved the sonics.
=================
My Speakers...
Each 3-way Full Range is bi-amped with one Krell KSA250 located just behind the speaker. A Krell KRX-1 electronic crossover with 18db/octave at 200Hz is used for for bass-MT outputs to each amp. One KSA250 channel direct drives the 2 ohm bass panel, and the second channel drives Apogee's M-T interface box which is ~4 ohms. This interface box contains a large toroidal step up transformer for the 0.14 ohm M-ribbon, plus resistors to step up the tweeter ribbon resistance to ~4 ohms, plus a 6db/octave passive L + C Xover at 10Khz. This is a very robust setup for the Full Range.
I have built DIY amps which direct drive the 0.1 ohm midrange ribbon and 2 ohm tweeter ribbons. Direct drive always produces greater dynamics and detail, but it is also easier to damage a ribbon by human error.
Thanks! Just what I was looking for! I'll borrow an higher grade measuring device then my own to get some accurate readings. However when I replace the ribbons someday (will probably happen) it may change again ofcourse..
I'm now thinking of going 3 way active using hypex modules. The DLCP digital 6 channel preamp/crossover, 4 x nc400 (570 watt/2ohms) for mid/high and 2 x ucd2000 (2000 watt/2ohms), can aquire those with some equipment trades so I can atleast get everything running.
So I wont need to reconstruct the passive crossover anymore but will still need the step-up transformer.
However it seems somebody in my country has 4 of once custom made sowther transformers for the full range for both mid/high. What are the odds
Now they're rated for 300 watts with 50% (so 150 watts) continuous load, it may do, I dont know, if loaded with over 150 watts continously theyll overheat.
Almost there, cant wait to have these babies playing, they were my childhood dream system.
I'm now thinking of going 3 way active using hypex modules. The DLCP digital 6 channel preamp/crossover, 4 x nc400 (570 watt/2ohms) for mid/high and 2 x ucd2000 (2000 watt/2ohms), can aquire those with some equipment trades so I can atleast get everything running.
So I wont need to reconstruct the passive crossover anymore but will still need the step-up transformer.
However it seems somebody in my country has 4 of once custom made sowther transformers for the full range for both mid/high. What are the odds
Now they're rated for 300 watts with 50% (so 150 watts) continuous load, it may do, I dont know, if loaded with over 150 watts continously theyll overheat.
Almost there, cant wait to have these babies playing, they were my childhood dream system.
From Pieter Treurniet:
"What am I missing that you guys keep talking about step-up transformers?
Function of the transformer here is to adapt the low impedance ribbon to the amplifier; the amp likes to see a 4 ohm reflected load. When the midrange ribbon is 0.1 ohm (which will be about right when I calculate the DC resistance of a 50 mm wide, 10 mu thick and 2 meters long aluminium midrange ribbon) we need a 4 : 0.1 ohm step-down transformer, which will have a turn ratio of some 6.3 : 1. Therefore it will have 16 dB of attenuation at the same time.
Other point is that for a transformer working from 300 Hz and higher it is not necessary, even not very clever, to pick a "150 watt transformer core"; power at these frequencies is much less.
You can do it with autoformers as well but be sure that the amplifier output is DC free".
PS. Pieter asked me to post this for him.
"What am I missing that you guys keep talking about step-up transformers?
Function of the transformer here is to adapt the low impedance ribbon to the amplifier; the amp likes to see a 4 ohm reflected load. When the midrange ribbon is 0.1 ohm (which will be about right when I calculate the DC resistance of a 50 mm wide, 10 mu thick and 2 meters long aluminium midrange ribbon) we need a 4 : 0.1 ohm step-down transformer, which will have a turn ratio of some 6.3 : 1. Therefore it will have 16 dB of attenuation at the same time.
Other point is that for a transformer working from 300 Hz and higher it is not necessary, even not very clever, to pick a "150 watt transformer core"; power at these frequencies is much less.
You can do it with autoformers as well but be sure that the amplifier output is DC free".
PS. Pieter asked me to post this for him.
Update:
-I've measured the ribbons, 0.1 ohm for MF, 0.9 for HF, so seems around the same as LineSource's readings.
-Since I'll be replacing the ribbons someday Ive emailed Graz for impedance figures of his replacement ribbons, but no reply so far.
-Peter Treurniet of Tribute Audio Transformers, very helpfull guy btw, is making potted amorphous c-core step-down transformers for the midrange at a decent price, he has actually made some for Graz in the past.
So getting there Only thing i'm doubting are the LF amplifiers, the hypex nc400 outputs 570W/2Ohms with a 24A limit. Alternatively I could get the ucd2000 which output 2000W/2Ohms with a 50A limit. The nc400's output impedance is 10 times lower then the ucd2000's and Ive heard em, the NC400 sounds much better. SO Prefer the NC400 but will it be strong enough!!
-I've measured the ribbons, 0.1 ohm for MF, 0.9 for HF, so seems around the same as LineSource's readings.
-Since I'll be replacing the ribbons someday Ive emailed Graz for impedance figures of his replacement ribbons, but no reply so far.
-Peter Treurniet of Tribute Audio Transformers, very helpfull guy btw, is making potted amorphous c-core step-down transformers for the midrange at a decent price, he has actually made some for Graz in the past.
So getting there
Only thing i'm doubting are the LF amplifiers, the hypex nc400 outputs 570W/2Ohms with a 24A limit. Alternatively I could get the ucd2000 which output 2000W/2Ohms with a 50A limit. The nc400's output impedance is 10 times lower then the ucd2000's and Ive heard em, the NC400 sounds much better. SO Prefer the NC400 but will it be strong enough!!
Why a transformer when he could use resistors and match impedance with the bass panel ...
Update:
-I've measured the ribbons, 0.1 ohm for MF, 0.9 for HF, so seems around the same as LineSource's readings.
-Since I'll be replacing the ribbons someday Ive emailed Graz for impedance figures of his replacement ribbons, but no reply so far.
-Peter Treurniet of Tribute Audio Transformers, very helpfull guy btw, is making potted amorphous c-core step-down transformers for the midrange at a decent price, he has actually made some for Graz in the past.
So getting there
The NC400 would be a poor choice at that impedance , if you examine its distortion spectra you will see its knee is at 100 watts giving you best sonics at 10 amps, the 24amp rating is greek mythology if wanting good sonics ..
Regards
I have the hypex dlcp and 6 ncore's sitting here for a while now.
Waiting for the midrange transformer from tribute audio but it's been 3 months now, running out of patience on those so one of these days I'm gonna hook it all up with a 2 Ohm resistor for the midrange and see what happens. I'll see if I can cancel the order and get some transformers elsewhere if it doesnt work out.
The dlcp suprises me in pure SQ performance, it sounds significantly better using it as a 2 channel dac then my former modded lavry da-11 did! More dynamic, more musical. Currently experimenting with powersupplies on it, gonna try simple C, CRC, LCLC, superregs, in stead of the aux on a smps600, may make a difference, may not
Waiting for the midrange transformer from tribute audio but it's been 3 months now, running out of patience on those so one of these days I'm gonna hook it all up with a 2 Ohm resistor for the midrange and see what happens. I'll see if I can cancel the order and get some transformers elsewhere if it doesnt work out.
The dlcp suprises me in pure SQ performance, it sounds significantly better using it as a 2 channel dac then my former modded lavry da-11 did! More dynamic, more musical. Currently experimenting with powersupplies on it, gonna try simple C, CRC, LCLC, superregs, in stead of the aux on a smps600, may make a difference, may not
Full Range stock cross over
I just brought home my fully restored Apogee full Ranges. Unbelievably heavy to carry into my basement with 4 guys for each crate/module They are now assembled. But I still have not been able to listen to how well they will sound restored yet!!!
Would anyone have any photos or be able to verify how to wire up the transformer portions of my stock impedance box?
I needed to rebuild my stock impedance box, because the original owner removed a lot of capacitors and I do not trust if he wired up the impedance transformer correctly.
Specifically, does anyone know if it matters on the mid-range impedance transformer of which polarity on the speaker side to solder up the transformer to? I have seen some photos showing the top side of the transformer going to the red lead and the bottom wire coming off of the transformer going to the black lead. Is this correct?
On the speaker side of the box the top black heavy 6 gauge wire goes to the top black colored post with the bottom going to the white post. Is that correct?
Also, I notice my larger black 6 gauge winding is not wrapped uniformly around the toroidal impedance transformer. It seems to go only about half way around apparently avoiding the bass panel transformer? Would it interact if I spread the 6 gauge wire around evenly near the other bass panel transformer?
The reason I am asking is because the prior owner had modified my interface box and I found it had some original wonder caps missing.
I can figure out the capacitors, but do not know if the mid-range transformer needs to be wired to the correct polarity or I worry there might be phase issues?
Thanks, Bill
I just brought home my fully restored Apogee full Ranges.
Unbelievably heavy to carry into my basement with 4 guys for each crate/module They are now assembled. But I still have not been able to listen to how well they will sound restored yet!!!Would anyone have any photos or be able to verify how to wire up the transformer portions of my stock impedance box?
I needed to rebuild my stock impedance box, because the original owner removed a lot of capacitors and I do not trust if he wired up the impedance transformer correctly.
Specifically, does anyone know if it matters on the mid-range impedance transformer of which polarity on the speaker side to solder up the transformer to? I have seen some photos showing the top side of the transformer going to the red lead and the bottom wire coming off of the transformer going to the black lead. Is this correct?
On the speaker side of the box the top black heavy 6 gauge wire goes to the top black colored post with the bottom going to the white post. Is that correct?
Also, I notice my larger black 6 gauge winding is not wrapped uniformly around the toroidal impedance transformer. It seems to go only about half way around apparently avoiding the bass panel transformer? Would it interact if I spread the 6 gauge wire around evenly near the other bass panel transformer?
The reason I am asking is because the prior owner had modified my interface box and I found it had some original wonder caps missing.
I can figure out the capacitors, but do not know if the mid-range transformer needs to be wired to the correct polarity or I worry there might be phase issues?
Thanks, Bill
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