To Sub Or Not To Sub, That Is The Question

Lagonda said:

How is the transparency of the CR 1 ? I have not heard the best reports about it. Only a few active crossovers a have heard let all the treble energy trough from a good analog source signal.

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Only good results here..... I've mastered a lot of albums with it.

Bruce B said:

Only good results here..... I've mastered a lot of albums with it.

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Good to know. Did you ever try the current Wilson Crossover?

I've been particularly interested in the discussion of the CR-1's transparency. I have not personally received any negative feedback about transparency until now, and it's not something I've experienced with the CR-1 myself. Since treble has specifically been mentioned, I decided to take some measurements of what's happening in the tweeter of a speaker with the CR-1 in and out of the system. These are near-field measurements with the mic directly in front of the tweeter's center. This should minimize the acoustic effects of my office. I used an inexpensive powered speaker that doesn't have the greatest frequency response, but it's what I had close by and still effectively demonstrates the point.

The first graph is zoomed way into the treble region, displaying only 1750Hz to 20kHz (1750Hz is where this tweeter is crossed over). This gives us a microscopic look at what's happening. The red trace is the speaker without the CR-1 connected to the system at all. The green trace is the CR-1 hooked up, but in bypass mode. The yellow trace is the CR-1 with the crossover engaged.



Below 1750Hz is not relevant to the test, but here's a zoomed out view just to give you a frame of reference at normal scale with the entire frequency spectrum.



We can see that the three response curves are right on top of each other. The tiny variations are well within the margin of error.

Side note: the bypass mode on the CR-1 effectively removes it from your system completely. It is a "true bypass" device. The signal goes through the input and right back out of the outputs. The CR-1 doesn't even need to have power connected to be bypassed. This allows for easy comparisons of your system with and without the CR-1 in the chain.

Just a quick test I thought some might find interesting or useful. I always like an excuse to hook up a mic and experiment.

thansen said:

I've been particularly interested in the discussion of the CR-1's transparency. I have not personally received any negative feedback about transparency until now, and it's not something I've experienced with the CR-1 myself. Since treble has specifically been mentioned, I decided to take some measurements of what's happening in the tweeter of a speaker with the CR-1 in and out of the system. These are near-field measurements with the mic directly in front of the tweeter's center. This should minimize the acoustic effects of my office. I used an inexpensive powered speaker that doesn't have the greatest frequency response, but it's what I had close by and still effectively demonstrates the point.

The first graph is zoomed way into the treble region, displaying only 1750Hz to 20kHz (1750Hz is where this tweeter is crossed over). This gives us a microscopic look at what's happening. The red trace is the speaker without the CR-1 connected to the system at all. The green trace is the CR-1 hooked up, but in bypass mode. The yellow trace is the CR-1 with the crossover engaged.

View attachment 133681

Below 1750Hz is not relevant to the test, but here's a zoomed out view just to give you a frame of reference at normal scale with the entire frequency spectrum.

View attachment 133682

We can see that the three response curves are right on top of each other. The tiny variations are well within the margin of error.

Side note: the bypass mode on the CR-1 effectively removes it from your system completely. It is a "true bypass" device. The signal goes through the input and right back out of the outputs. The CR-1 doesn't even need to have power connected to be bypassed. This allows for easy comparisons of your system with and without the CR-1 in the chain.

Just a quick test I thought some might find interesting or useful. I always like an excuse to hook up a mic and experiment.

Click to expand...

From my experience, whenever people talk about adding a crossover device causing a loss of transparency, they are almost never talking about the frequency response changing in the treble region (and when I have heard it). It is usually just a description of this sense that something sounds different. Is it some sort of low level harmonic distortions (which we can see on your measurements are clearly not happening)? Or is it some sort of low level noise added to the signal? It's really hard to know.

The objectivists would say if you can't measure something within the limits of "known" audability, the effect must be placebo so people are just imagining that crossovers like CR1 is causing loss of transparency when they're not.
Subjectivists would say some things are measureable but assumed not to be within the limits of audability but in fact are, or as with interconnect cables, some things are not measureable but can still cause sonic differences.

Ultimately though, I think for the vast majority of people, most of the time, the objectivists are correct. It is much more likely that subwoofer and speaker system are not integrated properly in the frequency domain (or time domain) causing sonic issues, rather than the crossover not being sufficient transparent causing sonic degradation.

ecwl said:

From my experience, whenever people talk about adding a crossover device causing a loss of transparency, they are almost never talking about the frequency response changing in the treble region (and when I have heard it). It is usually just a description of this sense that something sounds different. Is it some sort of low level harmonic distortions (which we can see on your measurements are clearly not happening)? Or is it some sort of low level noise added to the signal? It's really hard to know.

The objectivists would say if you can't measure something within the limits of "known" audability, the effect must be placebo so people are just imagining that crossovers like CR1 is causing loss of transparency when they're not.
Subjectivists would say some things are measureable but assumed not to be within the limits of audability but in fact are, or as with interconnect cables, some things are not measureable but can still cause sonic differences.

Ultimately though, I think for the vast majority of people, most of the time, the objectivists are correct. It is much more likely that subwoofer and speaker system are not integrated properly in the frequency domain (or time domain) causing sonic issues, rather than the crossover not being sufficient transparent causing sonic degradation.

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Interesting...I have also read that there can be a more life-like fullness and foundational weight to the entire midrange (not just bass) with great sub setups even at low crossover levels (sub 40hz). So there can be a LOT going in elsewhere in the frequency range it seems that might be changing with the insertion of a crossover device, and so it may not be only 'more equipment in the chain means loss of transparency'.

ecwl said:

From my experience, whenever people talk about adding a crossover device causing a loss of transparency, they are almost never talking about the frequency response changing in the treble region (and when I have heard it). It is usually just a description of this sense that something sounds different. Is it some sort of low level harmonic distortions (which we can see on your measurements are clearly not happening)? Or is it some sort of low level noise added to the signal? It's really hard to know.

The objectivists would say if you can't measure something within the limits of "known" audability, the effect must be placebo so people are just imagining that crossovers like CR1 is causing loss of transparency when they're not.
Subjectivists would say some things are measureable but assumed not to be within the limits of audability but in fact are, or as with interconnect cables, some things are not measureable but can still cause sonic differences.

Ultimately though, I think for the vast majority of people, most of the time, the objectivists are correct. It is much more likely that subwoofer and speaker system are not integrated properly in the frequency domain (or time domain) causing sonic issues, rather than the crossover not being sufficient transparent causing sonic degradation.

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Very thoughtful response. The reality is, that if someone hears a difference, then there is a difference. Even when a difference can't be measured or quantified, or heard by someone else.

I take both the objective and subjective approach, as I'm sure many do. I use measurements and data to get it where it's "right", and then I tweak to taste.

I was trained to S.O.A.P. everything....

thansen said:

I've been particularly interested in the discussion of the CR-1's transparency. I have not personally received any negative feedback about transparency until now, and it's not something I've experienced with the CR-1 myself. Since treble has specifically been mentioned, I decided to take some measurements of what's happening in the tweeter of a speaker with the CR-1 in and out of the system. These are near-field measurements with the mic directly in front of the tweeter's center. This should minimize the acoustic effects of my office. I used an inexpensive powered speaker that doesn't have the greatest frequency response, but it's what I had close by and still effectively demonstrates the point.

The first graph is zoomed way into the treble region, displaying only 1750Hz to 20kHz (1750Hz is where this tweeter is crossed over). This gives us a microscopic look at what's happening. The red trace is the speaker without the CR-1 connected to the system at all. The green trace is the CR-1 hooked up, but in bypass mode. The yellow trace is the CR-1 with the crossover engaged.

View attachment 133681

Below 1750Hz is not relevant to the test, but here's a zoomed out view just to give you a frame of reference at normal scale with the entire frequency spectrum.

View attachment 133682

We can see that the three response curves are right on top of each other. The tiny variations are well within the margin of error.

Side note: the bypass mode on the CR-1 effectively removes it from your system completely. It is a "true bypass" device. The signal goes through the input and right back out of the outputs. The CR-1 doesn't even need to have power connected to be bypassed. This allows for easy comparisons of your system with and without the CR-1 in the chain.

Just a quick test I thought some might find interesting or useful. I always like an excuse to hook up a mic and experiment.

Click to expand...

But in your zoomed out view there's significant differences lower down in the frequency response that would definitely be audible. If you did not move the mic or speaker between each, we shouldn't see those?

thansen said:

Very thoughtful response. The reality is, that if someone hears a difference, then there is a difference. Even when a difference can't be measured or quantified, or heard by someone else.

Click to expand...

At the risk of being called an objectivist, the above isn't necessarily true. If you say this without any disclaimers, then you are effectively claiming that cognitive biases and/or placebo effects are made up concepts?

For someone with a million dollar system to hear differences that are not there because they know they've inserted a component like the CR-1 in their system would not be unheard of.

Just for clarity; I have no idea if the CR-1 is transparent or not, that's not the point.

Danielaruso said:

Hey - this is not accurate.

You can completley bypass the CR1 with all xlr

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Haha... Of course you're right. I'm referring to the fact that once you hooked up the CR1, you cannot set CR1 to be in 100% bypass mode so you can just hear the preamp feed the CR1 the full signal and the CR1 to bypass the signal and feed it back to your speaker amplifier. I probably should have specified better.

sigbergaudio said:

But in your zoomed out view there's significant differences lower down in the frequency response that would definitely be audible. If you did not move the mic or speaker between each, we shouldn't see those?

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I only measured the tweeter up close. Anything below about 1750 Hz wasn’t being measured. It’s just background noise.

ecwl said:

Haha... Of course you're right. I'm referring to the fact that once you hooked up the CR1, you cannot set CR1 to be in 100% bypass mode so you can just hear the preamp feed the CR1 the full signal and the CR1 to bypass the signal and feed it back to your speaker amplifier. I probably should have specified better.

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The CR-1 can indeed by fully bypassed. There is a bypass switch that routes the signal from the inputs right back to the outputs. As long as you are using all XLR or all RCA, this is possible. It can’t convert between balanced and unbalanced when bypassed, since the signal isn’t going through the CR-1’s circuitry. As long as your cable types all match, you can even unplug power from the CR-1 and the signal passes right through. It’s a “true bypass” device.

thansen said:

The CR-1 can indeed by fully bypassed. There is a bypass switch that routes the signal from the inputs right back to the outputs. As long as you are using all XLR or all RCA, this is possible. It can’t convert between balanced and unbalanced when bypassed, since the signal isn’t going through the CR-1’s circuitry. As long as your cable types all match, you can even get plug the power from the CR-1 and the signal passes right through. It’s a “true bypass” device.

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Oops. You’re right. I should have read the manual more carefully.

I have a CR1 with a pair of fathoms. I would prefer to not have a crossover, but it is the only way to remove a 60Hz mode in my situation. I also do not think my preamp would happy with the impedance situation going to the sub inputs. The CR1 does dull the HF on my JBL 4367 speakers, which are very sensitive speakers witch electronics and cables. I now have a pair of TAD ME1s and was considering trying a Trinnov Nova or Danville crossover in part to solve that dulling. That is until I plugged in a better power cable and power distributer. Now I can not really hear a difference when crossover is on or when it is bypassed. Each stereo has its own bass issues (or lack of issues), but the CR1 is really easy to set up with acoustic measurements. The features included on it are fantastic. My nightmare was marriage of the sub placement, speaker placement and listening position. Of course there is major difference between the crossover slopes, but that is a whole other ball of wax.

x1992 said:

I have a CR1 with a pair of fathoms. I would prefer to not have a crossover, but it is the only way to remove a 60Hz mode in my situation.

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I deal with this acoustically, using ASC Isothermal TubeTraps and regular TubeTraps.

I also have a pair of Fathoms, but no crossover.

One of the first discoveries I’ve made is always use two subs for two channel. Of course you could always start with one and add the other latter. But given the choice between one super sub and two great ones I’d choose two over one. It just seems to work better with two.

One problem with two channel sub placement is many use directions and designs for home theater. For instance placing subs in corners works well with home theater, not two channel.

The next problem I very often is placing subs behind the speakers or to right or left of the main speakers. The reason many try this is to keep the subs in phase with the main loudspeakers. Which of course is very important.

Probably the worst “offense” committed when integrating subs in a two channel system is playing them too loud. Many people believe one should hear the subs. That works well for home theater where one generally enjoys the thump and explosions.
The key to two channel subs is to NOT hear them. One doesn’t want be reminded that subs are even in the room. If you can hear them then you are missing out on bass and mid bass information that’s being hidden by the subs.

Where to place them?
I’ve found that placing the subs along the sidewalls about midway into the room is a great position. Usually that means the subs will be positioned between you and the main speakers. This is generally a very neutral place in the room and the subs don’t have corners to boost their output.

When subs are placed on the sidewalls as proposed it’s relatively easy to blend them with the mains. The most difficult task is getting them in phase with the main loudspeakers so the woofers in the subs and mains aren’t working against each other. If there is less bass when the subs are playing then the subs and speakers are out of phase.

Getting the subs and mains to play together in phase usually requires an assistant. One person to sit in the listening chair and the other to to turn the phase control slowly back and forth while playing a a favorite recording. As the phase knob is turned listen to the differences in sound. I usually divide the phase knob in four quarters and listen to one quarter at a time. After you’ve decided on which quarter sounds best then slowly turn the phase knob until the subs a mains blend together. If your subs have a remote control this task can be accomplished much quicker. Shame on subwoofer makers who do not furnish a remote control.

Next adjust the volume of the subs so that they blend with the main speakers. One shouldn’t hear any boomy, loud distorted bass, or allow the subs to mask the details your main speakers already provide. Play some recording with natural bass, drums, piano, even voices that you’re very familiar with. Keep turning the volume of the subs a bit at a time so that you actually start hearing the recoding venues acoustics not your rooms. If in doubt turn them down. One can always turn them back up a bit. Try to avoid your first inclination. Which for many is, “ I want to hear lots of bass from my subs.” especially after paying a small fortune with them. I’ve done this plenty of times for sure myself.

There are lots of other tricks also that I could add but I’m tired of typing on my iPhone. So I’ll refrain unless others ask for more.

Enjoy!

DonH50 said:

This is neat, I have not used a phone app! I do want to highlight that @sigbergaudio noted most phone apps are limited in low frequency response, as are most SPL meters. C weighting rolls off at 30 Hz and below so is not accurate for deep subwoofer frequencies. It sounds like a great method for matching levels at the crossover frequency, where it is most important.

This may already be in the article (I only quickly skimmed), but you can play a tone at the crossover frequency with the phone (SPL meter) at the listening position, with sub and mains playing. Adjust the sub's phase for maximum SPL; that should be when subs and mains are in phase. Then adjust sub level(s) appropriately.

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It’s easier to reverse the speaker cables to your one main (either the Channel you sub is on if using two or the closest to the sub of only using one.). Mute or disconnect the other main channel.

Then find the NULL at your crossover frequency. Correct your cables and you have aligned the wave front (temporal phases) of your sub and main speaker.

The NULL is easier to see on a meter for some reason than a maximum.

I use REW and its Sound pressure level function and my UMIK microphone. It’s far better than an iPhone. Adjust the phase on my JL Audio F113v2 subs one channel at a time, watching the meter on my PC.

One key is to have the microphone at the listening position. That’s where you want the two speakers (main and Sub) to meet…

That is a Barry Ober technique.