Ron’s New System
- Thread starter Ron Resnick
- Start date
Sorry, may be I am missing something on your post - are you really asking about using the same exact speaker crossover before the amplifier? This approach can't be used, the impedance and absence of load on the crossover forbid it.
To be clear it's not a crossover. It's a simple high pass filter -- 500Hz at 6dB -- conducting the full range signal into the midrange/tweeter driver.
I want to relocate this high pass filter before the amplifier instead of after the amplifier. (I appreciate that the line-level signal will not require the same power handling capacity as the high pass filter components located after the amplifier.)
Can I use the same exact discrete component values?
Won't the input impedance of the amplifier cause the component values to change?
Last edited:
I think you mean 'blocking the full range signal from the midrange/tweeter driver'?
To the first, no, to the second question, yes.
First you need the input impedance. On that amp its not easy to find online. Ask the manufacturer or you may have to use a Digital VoltMeter to measure the resistance between the center of the RCA to the outside of the RCA.
Once you know that you need to sort out the capacitor that will cause a -3dB point at 500Hz. Here's the formula:
C = 1 / (2 * π * f * R)
The C value will be in Farads which is inconvenient. So I usually replace the 1 in the formula with 1,000,000, which will give us a result in microfarads. Let's take the example of 100K input impedance:
C= 1,000,000/6.28 x 500Hz x 100K The cap would be about 0.0032uf, use 0.0033 since you have to use an actually available value.
That cap might be so small since it only needs to handle a few Volts, you might be able to snug it into an RCA connector at the end of a cable.
Passive line level crossovers made to order
Class B amplifiers are those in which the output transistors only conduct during half (180 degrees) of the signal waveform
A Class C amplifier is a type of electronic amplifier where the amplifying device (typically a transistor) is biased such that it only conducts for less than half of the input signal's cycle
None of the amps in audio are Class C.
No worries.
The other thing that I forgot to mention is that there is a lot of energy stored in boxes and crossovers.
A 1st stores the least, and an active XO has much more immediate damping factor as the amp is driving the speaker like Ralph mentioned in his “pros #2” section.
As you like that speaker, it should be even more immediate with going active, and the decay/release will be more immediate.
It won’t matter a lot for steady state notes, but will help with the impulse sounds, and the attack/decay.
The big Clarisys system at the Munich show was using a digital active crossover from Accuphase, interestingly.
IMO you must measure it like Ralph suggested - probably the same for the capacitors used to make the filter. Many common capacitors have a 10% tolerance, you should make it using two capacitors in parallel if wanting exact values. If you do not like maths you can use this calculator:
https://www.digikey.com/en/resource...sion-calculator-low-pass-and-high-pass-filter
My dear friend Robbes, a former mastering engineer, has been over to the house countless times. (Fortunately he lives only about 22 minutes away.)
He visited again last night. He proved to me that TubeTraps really do change the sound.
For the last few months I have had stacked TubeTraps diffusion inside out, covering the first rear (front wall) reflection points. Robbes fiddled for a few hours last night with different combinations and different locations of TubeTraps.
Listening leisurely this morning the new configuration:
1) improves resolution
2) de-muddifies the low to middle bass
3) significantly wider sound-stage
4) slightly brightens the overall tonal balance.
On Reference Recordings' Symphony Fantastique (still, in my view, one of the best quality recordings of classical music in history, with stunning resolution, naturalness and zero brightness) the rolling thunder of tympani builds to crescendos but loses the resolution I hear on Ali's Trio G3/Berning/EMIA/VAC/Continuum Caliburn system.
Well I don't hear that muddiness anymore! It's a pretty unmistakable difference. (It's unfortunate I don't have more patience to do these kinds of experiments myself.)
I keep seeing the now-uncovered blue dots on the front wall which indicate the front wall rear first reflection points, and thinking the overall tonal balance is a touch brighter. But I don't want to give up this improved bass resolution.
I'll experiment with putting just one TubeTrap covering the front wall first reflection points (rather stacked) and hear what I hear.
He visited again last night. He proved to me that TubeTraps really do change the sound.
For the last few months I have had stacked TubeTraps diffusion inside out, covering the first rear (front wall) reflection points. Robbes fiddled for a few hours last night with different combinations and different locations of TubeTraps.
Listening leisurely this morning the new configuration:
1) improves resolution
2) de-muddifies the low to middle bass
3) significantly wider sound-stage
4) slightly brightens the overall tonal balance.
On Reference Recordings' Symphony Fantastique (still, in my view, one of the best quality recordings of classical music in history, with stunning resolution, naturalness and zero brightness) the rolling thunder of tympani builds to crescendos but loses the resolution I hear on Ali's Trio G3/Berning/EMIA/VAC/Continuum Caliburn system.
Well I don't hear that muddiness anymore! It's a pretty unmistakable difference. (It's unfortunate I don't have more patience to do these kinds of experiments myself.)
I keep seeing the now-uncovered blue dots on the front wall which indicate the front wall rear first reflection points, and thinking the overall tonal balance is a touch brighter. But I don't want to give up this improved bass resolution.
I'll experiment with putting just one TubeTrap covering the front wall first reflection points (rather stacked) and hear what I hear.
Last edited:
Would have taken your post more seriously if not for this part - where are the hyperbole police when you need them
Ron, I have always found less is more with tube traps. Your before and after photographs seem to confirm this. I suspect you hear more nuance and ambience also with the removal of traps. Less information being absorbed and lost in the room.
How did you determine that the new location is at the “first reflection point“ on the front wall? Have you played with rotating them so the reflective strip is not aimed at the listener? That might tone down the brightness.
How did you determine that the new location is at the “first reflection point“ on the front wall? Have you played with rotating them so the reflective strip is not aimed at the listener? That might tone down the brightness.
One person sits in the listening chair and another person holds a mirror.
not yet
 | Steve Williams Site Founder | Site Owner | Administrator |  | Ron Resnick Site Owner | Administrator |  | Julian (The Fixer) Website Build | Marketing Managersing |