Jump to content
The Klipsch Audio Community
Sign in to follow this  
joessportster

Bass Crossover Points ?

Recommended Posts

I have been on an endless (seems   endless anyway) experiment with  Full Range Drivers  and Bass Drivers in a 2 way set up My rational up to now has been cross the bass over low enough to keep vocals off the bass drivers. Allowing the Full Range to shine. Reading some reviews of other projects similar to mine I have gleaned some insight that they are crossing the bass drivers much higher .

Thinking about the probable advantages to crossing higher might be fuller sound,  better mid bass etc...  I  know  most heritage cross  over somewhere in the 4-500 range for the bass

 

Anyone here  have any insight to advantages or disadvantages of crossing the bass higher  ?

 

I started playing last night and  Perceived a fuller  sound but I also  got some  odd harmonics at certain freq  (that could easily be room  related) Plan on trying crossing over  much higher  to see what I might  hear. Am very  curious  to hear what others  might have experienced  or think.    As always thanks  for any info

Share this post


Link to post
Share on other sites

From Wiki:

"The voiced speech of a typical adult male will have a fundamental frequency from 85 to 180 Hz, and that of a typical adult female from 165 to 255 Hz".

 

And from NMSU website:

"Average fundamental frequency during conversation for males ranges from 100 to 150 Hz, whereas for females it ranges from 180 to 250 Hz. 

 

Harmonics go up from there, and these figures are conversational vs singing, but gets you in the ball park.

 

Share this post


Link to post
Share on other sites
14 hours ago, joessportster said:

I have been on an endless (seems   endless anyway) experiment with  Full Range Drivers  and Bass Drivers in a 2 way set up My rational up to now has been cross the bass over low enough to keep vocals off the bass drivers. Allowing the Full Range to shine. Reading some reviews of other projects similar to mine I have gleaned some insight that they are crossing the bass drivers much higher .

Thinking about the probable advantages to crossing higher might be fuller sound,  better mid bass etc...  I  know  most heritage cross  over somewhere in the 4-500 range for the bass

 

Anyone here  have any insight to advantages or disadvantages of crossing the bass higher  ?

 

I started playing last night and  Perceived a fuller  sound but I also  got some  odd harmonics at certain freq  (that could easily be room  related) Plan on trying crossing over  much higher  to see what I might  hear. Am very  curious  to hear what others  might have experienced  or think.    As always thanks  for any info

About the 5:30 mark he starts talking about the size of a driver, crossover frequencies, and off axis roll-offs. Certainly worth digesting. 

 

 

I added 3.3uf to the 8uf second order capacitor low pass in my klf10's. They normally cross at 2300hz. It flattened a downward slope of 2db between 1-2khz in the frequency response, and made the phase response slope a little less shallow, moving the crossover phase shift up by maybe 100hz, and smoothing out the impedance peak there also. It worked well with the changes I made to the horn. In my case, it gave me a pleasant filling of upper bass/lower midrange. Us horn lovers tend to want the horns to do as much of the work as possible, but we forget just how much information is already coming from the woofers. Measure, measure, measure.

  • Like 1

Share this post


Link to post
Share on other sites
On 4/25/2020 at 9:01 AM, joessportster said:

I have been on an endless (seems   endless anyway) experiment with  Full Range Drivers  and Bass Drivers in a 2 way set up My rational up to now has been cross the bass over low enough to keep vocals off the bass drivers. Allowing the Full Range to shine. Reading some reviews of other projects similar to mine I have gleaned some insight that they are crossing the bass drivers much higher .

Thinking about the probable advantages to crossing higher might be fuller sound,  better mid bass etc...  I  know  most heritage cross  over somewhere in the 4-500 range for the bass

 

Anyone here  have any insight to advantages or disadvantages of crossing the bass higher  ?

 

I started playing last night and  Perceived a fuller  sound but I also  got some  odd harmonics at certain freq  (that could easily be room  related) Plan on trying crossing over  much higher  to see what I might  hear. Am very  curious  to hear what others  might have experienced  or think.    As always thanks  for any info

If you can play with the crossover region, if you can get up to around 200hz, you can have great mid-bass and not lose what many consider the magic of a full range.  If you are not going to at least use an electronic crossover or cap to give a 6db slope to the fullrange than your fullrange needs to get down to around 50hz and drop your sub down to that range with at least a 12db crossover.  

It's all going to be a matter of establishing a good blend while not over-taxing the full range in the low frequencies. 

Share this post


Link to post
Share on other sites
24 minutes ago, pzannucci said:

If you can play with the crossover region, if you can get up to around 200hz, you can have great mid-bass and not lose what many consider the magic of a full range.  If you are not going to at least use an electronic crossover or cap to give a 6db slope to the fullrange than your fullrange needs to get down to around 50hz and drop your sub down to that range with at least a 12db crossover.  

It's all going to be a matter of establishing a good blend while not over-taxing the full range in the low frequencies. 

So far this is exactly what  I have settled  on 200 HZ happy so  far  Appreciate the  suggestion.    I   was running the FR  at Full Range  and simply crossing at 160  with the bass using the built  in crossover on the crown.  I put my Marchand back in crossing  at 200  HZ and the  sound was much different much more refined

Share this post


Link to post
Share on other sites

Joe, I don't think you are going to like the suggestion but I think you have to get a USB microphone and REW going. Until you know what is happening in the crossover area it is just throw it against the wall and see if it sticks. 

 

Reading the measurements helps you know where to cross and if you need to invert the polarity of a driver. 

 

Can you play with delay on the Marchand?

I got good results with the crown's DSP and running the Full Range at FR but nothing like the results of minimizing phase, crossing where the driver's tell you too and dialing in group delay.

 

REW is a lot at one time but if you attack it in small bites it is doable

 

 

  • Like 2

Share this post


Link to post
Share on other sites
14 minutes ago, joessportster said:

So far this is exactly what  I have settled  on 200 HZ happy so  far  Appreciate the  suggestion.    I   was running the FR  at Full Range  and simply crossing at 160  with the bass using the built  in crossover on the crown.  I put my Marchand back in crossing  at 200  HZ and the  sound was much different much more refined

Using a crossover where you have it will avoid bloat and distortion in the fullrange and provide you good midbass. Should work out well.

Share this post


Link to post
Share on other sites

Rich's suggestion to get a calibrated USB microphone (like a UMIK-1) is probably the best investment you can make in my experience, even if you're only using a small fraction of the information that REW can provide to you. Even if you wind up not using that microphone very often, simply using it one time can save you a lot of money downstream.  If you run one measurement, you can see many things that you otherwise wouldn't be aware of using your ears. If you do hear something and you can't put your finger on what's occurring, the measurements will enable you to isolate what the issues are. All you have to do is take one measurement using REW using your computer with your calibrated USB microphone--all for a $95 entry fee.

 

As far as where to cross, Rich's suggestion is right on, IMHO.  Let individual driver response tell you where that crossover should occur.  The phase and group delay changes at the ends of the driver's SPL response will tell you a lot. You can also see where the 1/4 wavelength room mode cancellations occur based on where you've put your loudspeakers and even your listening position. 

 

You can even play dual tones into your loudspeakers to see the sideband distortion peaks due to the same driver trying to play lower frequencies at the same time as higher frequencies.  Side band distortion has probably as much to do with setting the crossover point(s) as SPL and phase response, and you can read the amplitude of those peaks directly from the RTA plots. 

 

Chris

  • Like 1

Share this post


Link to post
Share on other sites
1 hour ago, Chris A said:

You can even play dual tones into your loudspeakers to see the sideband distortion peaks due to the same driver trying to play lower frequencies at the same time as higher frequencies.  Side band distortion has probably as much to do with setting the crossover point(s) as SPL and phase response, and you can read the amplitude of those peaks directly from the RTA plots.

 

I'd like to know more about this, can you please elaborate?

Share this post


Link to post
Share on other sites
2 hours ago, Chris A said:

Rich's suggestion to get a calibrated USB microphone (like a UMIK-1) is probably the best investment you can make in my experience, even if you're only using a small fraction of the information that REW can provide to you. Even if you wind up not using that microphone very often, simply using it one time can save you a lot of money downstream.  If you run one measurement, you can see many things that you otherwise wouldn't be aware of using your ears. If you do hear something and you can't put your finger on what's occurring, the measurements will enable you to isolate what the issues are. All you have to do is take one measurement using REW using your computer with your calibrated USB microphone--all for a $95 entry fee.

 

As far as where to cross, Rich's suggestion is right on, IMHO.  Let individual driver response tell you where that crossover should occur.  The phase and group delay changes at the ends of the driver's SPL response will tell you a lot. You can also see where the 1/4 wavelength room mode cancellations occur based on where you've put your loudspeakers and even your listening position. 

 

You can even play dual tones into your loudspeakers to see the sideband distortion peaks due to the same driver trying to play lower frequencies at the same time as higher frequencies.  Side band distortion has probably as much to do with setting the crossover point(s) as SPL and phase response, and you can read the amplitude of those peaks directly from the RTA plots. 

 

Chris

Thanks Chris. I already have a MIC and  REW downloaded I just dont know squat about using them other than taking a measurement..................I have no idea what I am looking at once a measurement is taken other than the knowledge that the flatter the better  in the 20 to 20K  range

Share this post


Link to post
Share on other sites
On 4/25/2020 at 8:01 AM, joessportster said:

I have been on an endless (seems   endless anyway) experiment with  Full Range Drivers  and Bass Drivers in a 2 way set up My rational up to now has been cross the bass over low enough to keep vocals off the bass drivers. Allowing the Full Range to shine. Reading some reviews of other projects similar to mine I have gleaned some insight that they are crossing the bass drivers much higher .

Thinking about the probable advantages to crossing higher might be fuller sound,  better mid bass etc...  I  know  most heritage cross  over somewhere in the 4-500 range for the bass

 

Anyone here  have any insight to advantages or disadvantages of crossing the bass higher  ?

 

I started playing last night and  Perceived a fuller  sound but I also  got some  odd harmonics at certain freq  (that could easily be room  related) Plan on trying crossing over  much higher  to see what I might  hear. Am very  curious  to hear what others  might have experienced  or think.    As always thanks  for any info

 

I run dual 15" drivers in reflex bins with horn loaded mids and top.  My ear tells me to keep the LF in the bins and not to allow it to creep up into the mid horn. 

And don't want the cone drivers to produce any of the mids as well. 

So I use an ESN design on my bass board.  

Could be just me.....or  only apply in a bass reflex unit ???

tc

 

Share this post


Link to post
Share on other sites

Joe, Start here and see if this helps at all

 

https://community.klipsch.com/index.php?/topic/187474-active-dsp-rew-xilica-101/&tab=comments#comment-2433931

 

Chris has lots of posts about how to set up the mic for measurements. Let's assume you are measuring one speaker at a time with absorption on the floor/walls with the Mic 1 meter from the speakers.

 

  • Use the tone generator on REW to get the HF and LF sections putting out the same SPLs by adjusting the Crown's gain, I'm assuming  your HF amp does not have gain control, if it does great. The idea is to get them to put out the same SPLs as best you can prior to measuring
  • Measure the bass bin and flatten it out with PEQs (REW helps a lot here)
  • Measure the HF and flatten it out
  • Remeasure each individually
  • Look for a spot between say 200 and 800 where the phase of the LF and HF are close to each other, I think Chris suggests within 90 degrees (please correct me if wrong I'm going from memory)
  • Cross the two drivers at that point

Once you have that you can start to look at the SPL, Phase, Group Delay and Spectrogram all from REW measurements to make things "better". When you get it right you will never think about using a 3-way system with passive networks ever again.

 

Initially it was a lot of work and for me and it would have been impossible without the help of @Chris A. I tended to focus too much on wanting to know what I was doing and why. But if you just accept the fact that if you do X, Y and Z you will be greatly rewarded you will get there quicker.

 

I can't tell you how many times I've flipped the polarity back and forth on one of the drivers with different crossover points ranging between 150 and 850. Once you know what to look for on the various graphs is it very obvious that you MUST do it. If you are playing around with crossover points I could easily see you needing one driver's polarity switched and you not knowing you need it without measurements. Later you can listen in real time and switch them back and fort and convince yourself it is correct.

  • Like 2

Share this post


Link to post
Share on other sites
2 hours ago, joessportster said:

Thanks Chris. I already have a MIC and  REW downloaded I just dont know squat about using them other than taking a measurement..................I have no idea what I am looking at once a measurement is taken other than the knowledge that the flatter the better  in the 20 to 20K  range

If you can get a measurement at all, you can email the resulting .mdat file to me, and we can start a dialogue on it.  Your call.  PM me.

 

Generally speaking, if you can set the microphone centered on-axis and about 40 inches from the front of the loudspeaker (one loudspeaker at a time), and place as much absorption material on the floor as possible (old blankets, comforters, foam rubber pads, etc.) from the loudspeaker to the microphone and about 3 feet wide, you'll be able to capture enough.  The measurement can then be saved to a file name.

 

3 hours ago, rplace said:

I'd like to know more about this, can you please elaborate?

 

Under the "Generator" icon at the top of the plot (the third button in the top row of icons), you can select "Multitone", and then "custom" to set the two frequencies of interest, then select either the "L" or "R" channel at the bottom of the dialog window, and then punch the bottom right green right-hand arrowhead in the box to play the dual tone.  If you then select the "RTA" button (real time analysis) on the top main icon row in the plot, you can capture the two frequencies in a continuous FFT display, and which will show the sidebands above and below the upper frequency that's being played.  This is called modulation distortion, and will create those sidebands--especially with direct radiating drivers (horn-loaded drivers have 20-25 dB lower sideband levels typically than the same drivers being used in direct radiator mode--like cone-type drivers or woofers. 

 

Make sure that the upper and lower driver frequencies are both within the same driver's operating band, otherwise you won't see much in the way of sidebands.  Here is a measurement using a partially horn-loaded bass bin in my room, with dual tones at 30 and 415 Hz:

 

871846723_Bassbin30and415HzdualtoneRTA.thumb.jpg.460903b6c6b92aff8d8c94281336604a.jpg

 

The better the horn loading, the lower the side band levels--on a relative scale.  Using these sideband levels, you can see the effects of changing the crossover points between bass bin and high frequency driver, etc.  On direct radiating drivers, these side band levels will be much higher at the same overall SPL for the two test tones.  This is what you hear as "opaqueness" in sound from loudspeakers.  Those distortion sidebands are created when playing music having more than a single sine-wave tone in it. The higher the drive levels (in SPL)--the higher the relative levels of the side bands (upper and lower). You also see the harmonic distortion frequencies (60, 90, 120, 150 Hz, etc.) which are produced from the woofer.  These are typically not nearly as objectionable to hear than modulation sidebands, which are not even harmonics of either the lower or upper driver frequencies.

 

Chris

  • Like 2

Share this post


Link to post
Share on other sites
On 4/27/2020 at 1:04 PM, joessportster said:

Thanks Chris. I already have a MIC and  REW downloaded I just dont know squat about using them other than taking a measurement..................I have no idea what I am looking at once a measurement is taken other than the knowledge that the flatter the better  in the 20 to 20K  range

Ah you have the tools.  Decide which driver you like the sound of in the overlap region.  Response perception may be different with the bass and full range driver sound/speed/dispersion.  Once you think you have that figured out, start flat and make it the way you like it.  No right way.

 

Start with all the suggestions once you know how to use the tools, then tweak from there.  Chris A's suggestions, once you get familiar with the tools, will get you the last 10%.

Share this post


Link to post
Share on other sites
On 4/27/2020 at 11:02 AM, rplace said:

I'd like to know more about this, can you please elaborate?

If you go to page 5 of the linked Klippel white paper, you will see a discussion on the effects of multiple tones being used to measure modulation distortion sidebands of loudspeakers, as well as their relative magnitudes to harmonic distortion peaks...as a function of the overall SPL (loudness):

 

https://pdfs.semanticscholar.org/2298/f8d16cfd5140002da418511204358b87de45.pdf

 

Chris

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...