verifying crossovers

[Nutznboltz]

For those with powered subs, how close are you getting when you verify with a multimeter?  I'm referring to the process of checking voltage on track 30 referenced to track 27 on the Vandertones disc.

Ive never been able to get .707vac      its usually closer to .8

[MNSki]

I’ve used a multimeter on a couple amps with the crossovers. With one it was right on the 0.707. The other time was a little off (I don’t recall the value). I called Richard and he said it was within the normal range and he wasn’t concerned. I have my crossovers in for battery replacement currently and can check values when they come back.

[ctsooner]

How often do the crossovers need a new battery?  Glad I have built in crossovers.  One less thing to worry about, lol. 

[MNSki]

They need to be changed every 7 or 10 years depending on the batteries used.

[ctsooner]

Makes sense.  Thanks for the share.  I have mine built into my Ayre AX5/20.  They used their best caps that they use in the ref gear etc...  I am going to sell it now that the HP5 is on order.  If anyone wants it???? lol....  

 

[CyC]

On 9/20/2020 at 12:03 PM, Nutznboltz said:

For those with powered subs, how close are you getting when you verify with a multimeter?  I'm referring to the process of checking voltage on track 30 referenced to track 27 on the Vandertones disc.

Ive never been able to get .707vac      its usually closer to .8

How exactly is this done?  I looked over the manual and it suggests to use equipment I do not own.  I didnt see instructions on using a Vandertone and a multimeter anywhere.  

[andrewtgt]

29 minutes ago, CyC said:

How exactly is this done?  I looked over the manual and it suggests to use equipment I do not own.  I didnt see instructions on using a Vandertone and a multimeter anywhere.  

I'll just quote Rutan's Audiogon post:

"Hook your Volt Meter set to AC Volts up to the speaker wires
at the amp or speaker with the High passes start at 50 k.
Play track 27 on repeat which is 1000hz and adjust your pre amps volume control to read as close to 1 Volt AC.
Next go to track 30 which is 100 hz and if the meter reads .707 or as close as you can get your set. If not start from beginning on trk 27 adjust dip switch settings repeat various listed settings until you get there.
JohnnyR"

You can use any cheap multimeter or voltmeter you can get your hands on, hook one probe to the + of the woofer terminal and the other probe to the -.

The .3 drop in Volts basically means  the crossover drops the sub volume by 3 decibels at 100Hz (a .2 drop means 2 decibels and .4 drop means 4 decibels).

 

 

[ctsooner]

thanks for sharing that.  I have heard Johnny say this a few times in our conversations, but it's all over my head unless I can also read it.  I have to say that every Vandy dealer I've met (at least half of them), do a wonderful job with set ups of any speaker.  They just get it.  Not all dealers are good with set ups IMHO.  

[MNSki]

CYC- if you list the amp you are using (& which crossover you use -  rca or xlr), someone may know the correct settings.

[CyC]

Ok, thanks...now I get it.  I know the specs on my Amp (McCormack DNA-1) but I am always one to try things out to know for sure.

[CyC]

Was able to test this out and my amp was nearly perfectly on point with the crossover settings as described.  Warming up my equipment an hour helped, it seems the values weren't consistant across both channels until about a hour warm up time.

[ctsooner]

great to hear that. Congrats and making good music.  Time to enjoy!!!!

[Robertsmania]

I'm upgrading from an ancient pair of 2W subwoofers to new Sub Threes.

I've been using a pair of X-2  XLR interconnects Richard made for me long ago and they did seem to work well with the 2Ws.  They are listed as 10K and that matches the advertised 10,000 Ohm input impedance on my amplifier.

I recently saw the instructions for verifying the crossover with multimeter you guys are discussing here:
https://www.vandersteen.com//media/files/Manuals/Vandersteen Audio Setup Data 80 Hertz High-Pass.pdf

But honestly, I'm a little confused. 
The document title and heading describe it as being for the Sub Three at 80Hz, but it looks like the instructions are really for verifying a 100Hz crossover point.

The PDF says:

Quote

Vandersteen Audio Set Up Data For 80 Hertz High-Pass (SUB THREE)

THE MOST IMPORTANT FIRST STEP IN THE SETUP IS SETTING THE 3DB DOWN POINT ACCORDING TO THE INPUT IMPEDANCE OF THE CUSTOMER'S (MAIN) AMPLIFIER. THIS PROCESS IS MORE ACCURATE. THAN LOOKING UP THE INPUT IMPEDANCE SPECIFICATION. TAKE ANY DIGITAL VOLTMETER SET TO AC VOLTS. WITH THE MAIN AMPLIFIER PROPERLY HOOKED UP TO THE MAIN SPEAKERS, VOLT METER ACROSS THE BLACK AND RED OUTPUT TERMINALS. PLAY THE KĒNTO CARBON VANDERTONES TEST DISC TRACK 27 (1000HZ) ADJUST THE PREAMP VOLUME FOR EXACTLY 1 VOLT. PLAY TRACK 30 (100HZ) AND THE VOLTAGE SHOULD BE .707 VOLTS. IF IT IS HIGHER THAN .707 ADJUST THE M5-HP CROSSOVER TO A HIGHER IMPEDANCE SETTING. IF THE VOLTAGE IS LESS THAN .707 ADJUST THE M5-HP TO A LOWER IMPEDANCE SETTING RUN THE PROCESS AGAIN ONCE YOU MAKE THE CHANGE TO VERIFY THAT THE IMPEDANCE SETTING IS CORRECT.

But the instructions in the vandertones.jpg included with the audio tracks says pretty much the same thing, but then goes on to say:

Quote

The same procedure can be used with trk# 31 to verify an 80Hz x-over.

And indeed, with my 10K X-2 in place, I'm much closer to the 0.707V target playing track 31.

So is it just an editing issue/typo and the pdf instructions for the Sub Three really should be saying to verify 0.707V on track # 31?
Or are the Sub Threes really supposed to have a 100Hz crossover (and I'll need to change the ones I have)?

 

Vandersteen Audio Setup Data 80 Hertz High-Pass.pdf

[Richard Vandersteen]

Hello,

The confusion may be because we use the same basic scheme for many different products.  The SEVEN (100Hz) , 5 (100Hz) , Quatro (100Hz) and new KENTO (200Hz) series speakers need the high-pass to be on the money for reliability and best sound.   The SUB NINE, SUB THREE, 2Wq and 2W use 80-100Hz but there is much flexibility  as the owners manual (the SUB THREE manual is not finished but is a combination of the 2Wq and Quatro set up) recommends trying input impedances that are one or two below, on the money and one up for best sound.  The SUB THREE is OK with your X-2 because the amplifier has not changed but it is not transparent enough for long term use with woofers of this quality.  Going from the 2Wq to the SUB THREE you have upped the anti and a M5-HPB is recommended  which is adjustable for many different input impedances and frequencies.

RV

[Robertsmania]

Thank you for the reply Richard! 

I was able to get a pair of M5-HPB crossovers and am eager to experiment with the various settings when my SUB THREEs get here.  Very exciting.

I also found the video of you going through the process for the low frequency room optimization.  Tremendously helpful and answered all the questions I had looking at the worksheet.

https://www.youtube.com/watch?v=7C60LoHGtI0

Edited January 25, 2021 by Robertsmania

[ctsooner]

Thanks for the video share Roberts.  Heading over there now.  

[Robertsmania]

On 1/18/2021 at 7:10 PM, Richard Vandersteen said:

Hello,

The confusion may be because we use the same basic scheme for many different products.  The SEVEN (100Hz) , 5 (100Hz) , Quatro (100Hz) and new KENTO (200Hz) series speakers need the high-pass to be on the money for reliability and best sound.   The SUB NINE, SUB THREE, 2Wq and 2W use 80-100Hz but there is much flexibility  as the owners manual (the SUB THREE manual is not finished but is a combination of the 2Wq and Quatro set up) recommends trying input impedances that are one or two below, on the money and one up for best sound.  The SUB THREE is OK with your X-2 because the amplifier has not changed but it is not transparent enough for long term use with woofers of this quality.  Going from the 2Wq to the SUB THREE you have upped the anti and a M5-HPB is recommended  which is adjustable for many different input impedances and frequencies.

RV

Thank you for the clarification.

My amplifier is a Sunfire TGA-5200 and its documentation indicates the XLR input impedance is 10K Ohms (each leg).  The main speakers are 2Ce Signature IIs.

The fixed X-2 crossovers I have are labeled  10K.  They measure 0.193 uF which is close to the mathematical target for an 80Hz -3dB crossover if the amplifier's input impedance is listed correctly.  Indeed, the volt meter agrees with that showing 0.691V at 80Hz.  So it crosses just above 80Hz but its pretty close.

The setting on the M5-HPB that is the closest for my system is with switches 1,8,10 ON and is listed as 33k in the 2W documentation (20K on the sticker).  In any event, the volt meter reads 0.617V at 80Hz and 0.696V at 100Hz.

The only available setting lower than that is with switches 1,2,9,10 ON for 20K in the doc (10K sticker).  That measures 0.848V at 80Hz.  Using a signal generator that doesn't get to 0.707V for -3dB until 55Hz.  That seems way too low.

I do not appear to have an 80Hz option with my amplifier using the M5-HPB.  I had done some experiments with undocumented settings, and found that 1,9,10 showed a good volt meter reading, but calling in and double checking with Richard was told NOT to use that as it would be unbalanced.  Apparently switches 1/10 and 2/9 are linked and using either of the pair without the other puts asymmetrical capacitance on the legs.

 

For now I'm going to spend a few days with each one, listening to see if there is any clear advantage of the 100Hz/M5-HPB or 80Hz/X-2 as far as overall sound.

I set the level and contour values I've been using ear with the X-2s while breaking in the subs.  Switching between the crossovers and checking levels, its very close and only needs a slight bump on the SUB THREEs sensitivity to match the low end output when using the  M5-HPB.

 

I have not done any experiments with the low end room correction yet and wonder if there is an advantage to going with the 100Hz crossover for that?  The documentation for the other products using the equalization show pots 9,10,11 adjusting 84-120Hz.  If a SUB THREE is crossed over at 80Hz, would the adjustment levels at those frequencies be diminished?  

 

[GdnrBob]

If there is anyone who can answer those questions, besides Mr. V., it is John Rutan at Audioconnection.

He and his assistant Samir set up my Sub 3's using some rather sophisticated software.

If I recall correctly, he optimized the crossover settings first, then used a mic and software to set the contour levels. 

You seem to be doing this already, but you might wish to call Johnny directly for further instruction.

I hate to put up phone numbers here, so PM me if you are interested in calling him.

Bob

[ctsooner]

That makes a ton of sense Bob.  These set ups are out of my pay grade, lol..:). 

[Robertsmania]

Taking a look at some more settings, I think I may have a good 80Hz crossover with the M5-HPB using switches 2,8,10 ON.  

All the measurements I'm doing with undocumented settings are with the subs disconnected and I'll confirm this is okay before using them.

With the 0.5dB resolution on the volume control of my preamp, I can't get exactly 1.0V at 1KHZ.  So my approach is to get as close as possible, and then add/subtract the difference to the 0.707V target.  I've verified consistent results using the vandertones tracks as well as my signal generator, and have then a sine wave tone to find where the voltage does hit the adjusted target voltage and noted that as the observed xover point.

Edited February 22, 2021 by Robertsmania

[Robertsmania]

Crap, typo above...  Its correct in the spreadsheet, but I mistyped the value.  The one that seems to be a good 80Hz match is with 2,8,9 ON.

[GdnrBob]

@Robertsmania,

Since you seem to be well versed on setting these things up, I noticed Samir played a weird test sound.

It was a kind of 'BWoop' going from a low to high frequency.

What is that called?

Bob

[Robertsmania]

1 hour ago, GdnrBob said:

@Robertsmania,

Since you seem to be well versed on setting these things up, I noticed Samir played a weird test sound.

It was a kind of 'BWoop' going from a low to high frequency.

What is that called?

Bob

If it was very fast, its what they call a "quick sweep" and if it was longer (10-20 seconds) its a frequency sweep.  Maybe there is more correct terminology?

Its typically used with software on a computer and/or electronics in your system.

I use a program called Room EQ Wizard (REW).  Its free and with a relatively inexpensive USB microphone you can get pretty accurate and consistent measurements with a great deal of information.  I encourage anyone to take a look and try it out.  https://www.roomeqwizard.com  There are other programs that do similar things that are more professional, commercial and expensive.  I have no idea what Samir was using.

Hopefully, they were using a system to evaluate before and after calibration and using it to double check how things were working.  

There are systems like Audyssey that use that bwoop, bwoop, bwoop sound to setup room correction filters.  I don't want to start a religious war or anything and if you are happy with the performance of your system, that's all that matters.  But many people (myself included) prefer not to use digital room correction for music systems.  Other people do like it and to each his own.  Vandersteen has stated that equalization is appropriate for bass, but nothing above that.