Elevating the Vandersteen Fully Passive Designs

[Schuesmp]

Over the course of yesterday and this morning, I recalibrated the powered bass sections of my Quatro Wood CT’s, which became necessary when I relocated the speakers within my relatively large listening space.

I employed the technique recommended by Vandersteen (Vandertones measured with Realistic 33-2050 Sound Level Meter), which improved the speakers’ performance in my room markedly, compared to their performance using the EQ settings established for the previous room placement. I actually enjoyed the process!

Mostly out of curiosity, I fired up the Real Time Analyzer in my AudioTools application for iPad and evaluated readings taken by a miniDSP UMIK-1 USB measurement calibrated microphone. This tool allowed me to further balance the speakers’ low and mid-bass output, as well as to address some nasties in the very low bass region (20-30 Hz) that I did not identify using the Vandertones and Realistic Sound Level Meter (likely human error).

I am REALLY pleased with the results and am enjoying excellent sound. I did my best to not over-EQ the powered bass, heeding Richard Vandersteen’s advice, which I understand could potentially result in a relatively dull presentation.

Thank you, Richard, for your helpful “Room Adjustable Bass” video available on YouTube, which was akin to an effective project kick-off meeting for my lazy butt. 😉

[Schuesmp]

I add to my post above that I was somewhat hesitant to follow the guiding measurements of low bass frequencies in my room (20-30 Hz) by lowering pots 1, 2, and 3 to at or near the minimum limits, but the result to my ears is unquestionably favorable and delivers exceptionally punchy, detailed, and satisfying bass. In fact, with these adjustments, the perception of deep bass (again, 20-30 Hz) is subjectively enhanced, while also presumably removing obstacles for the mid-bass and midrange frequencies. Such a gratifying result!

[Richard Vandersteen]

24 minutes ago, Schuesmp said:

I add to my post above that I was somewhat hesitant to follow the guiding measurements of low bass frequencies in my room (20-30 Hz) by lowering pots 1, 2, and 3 to at or near the minimum limits, but the result to my ears is unquestionably favorable and delivers exceptionally punchy, detailed, and satisfying bass. In fact, with these adjustments, the perception of deep bass (again, 20-30 Hz) is subjectively enhanced, while also presumably removing obstacles for the mid-bass and midrange frequencies. Such a gratifying result!

Your room has standing waves at those frequencies plus excessive room gain so they must be cut.  This is part of the process because cutting is the only adjustment that work as trying to fill a suck out will never work.  The pots on all of our speakers will only boost about 3 dB but are able to cut 21 db.  This is by design.  Open string on a stand-up bass is 42 Hz so except for synthesizer and pipe organ there is nothing at 20-30 Hz except mud.  This should have automatically happened by following the process outlined in the manual or video.  I agree the result is gratifying and is the reason it is designed the way it is.  I am happy some of you are playing with this because it not difficult and can be very rewarding sonically.   If we want the best out of our systems, we need to get involved by learning how to optimize the setup.  This often will result in a better improvement than throwing more money at a new component, wire, power line conditioner, etc.  Think of all the audio enthusiasts who don't have these options.  I think are mandatory or at least a benefit in 90% of our rooms.  RV

[Holmz]

2 hours ago, Schuesmp said:

Mostly out of curiosity, I fired up the Real Time Analyzer in my AudioTools application for iPad and evaluated readings taken by a miniDSP UMIK-1 USB measurement calibrated microphone. This tool allowed me to further balance the speakers’ low and mid-bass output, as well as to address some nasties in the very low bass region (20-30 Hz) that I did not identify using the Vandertones and Realistic Sound Level Meter (likely human error).

Thanks for ^that^.

Have you use LARSA or other tools?
I have the microphone, and picked up am iPad USB cord yesterday.
And I think that REW only work on windows.

[Schuesmp]

12 minutes ago, Richard Vandersteen said:

This should have automatically happened by following the process outlined in the manual or video. 

I did my best, but the readings using the Realistic Sound Level Meter at those low frequencies were somewhat difficult to interpret. I am in a very good place, now, and following the process described in your video contributed 90% to the excellent result I am experiencing.  

[Schuesmp]

15 minutes ago, Holmz said:

Thanks for ^that^.

Have you use LARSA or other tools?
I have the microphone, and picked up am iPad USB cord yesterday.
And I think that REW only work on windows.

I have not used those tools. The basic AudioTools application is not very expensive and recognized my miniDPS UMIK-1 microphone immediately - only required a USB-C to USB-A adapter (for my particular Apple iPad Air model), which conveniently was included with my somewhat recently purchased AudioQuest DragonFly Cobalt. 

[Richard Vandersteen]

33 minutes ago, Schuesmp said:

I did my best, but the readings using the Realistic Sound Level Meter at those low frequencies were somewhat difficult to interpret. I am in a very good place, now, and following the process described in your video contributed 90% to the excellent result I am experiencing.  

Yes, I understand it can be hard as the meter is jumping around all over the place because of noise.  This is why digital meters do not work very well because all that noise is averaged into the reading (false).  The beauty of a human is being able to see where the needle is most of the time.  That is the true reading coming from the speaker of these lower frequency bands prone to noise from the environment.  I have tuned my room with an expensive RTA (refreshing often to minimize the storage effect error,) and compared the result to doing it by the book with the Radio Shack analog meter, there is no comparison as the RTA method reminds me of the sound you get with DSP room correction (maybe because of the same averaging problem).  90% is better than most of the world lives with!   RV

[Schuesmp]

5 minutes ago, Richard Vandersteen said:

Yes, I understand it can be hard as the meter is jumping around all over the place because of noise.  This is why digital meters do not work very well because all that noise is averaged into the reading (false).  The beauty of a human is being able to see where the needle is most of the time.  That is the true reading coming from the speaker of these lower frequency bands prone to noise from the environment.  I have tuned my room with an expensive RTA (refreshing often to minimize the storage effect error,) and compared the result to doing it by the book with the Radio Shack analog meter, there is no comparison as the RTA method reminds me of the sound you get with DSP room correction (maybe because of the same averaging problem).  90% is better than most of the world lives with!   RV

Everything in your response rings true. My listening room sits atop a “crawl space” with an up to 24 foot ceiling height due to building on a very steep hill. Despite significant efforts to insulate and dampen, my Quatro Wood CT’s in combination with the suspended floors create a tympanic effect at  very low frequencies. The techniques described in my posts above have yielded incredible measured and subjective results in my room. As I type this, my Vandersteen’s are delivering goosebumps. 

[Richard Vandersteen]

51 minutes ago, Schuesmp said:

Everything in your response rings true. My listening room sits atop a “crawl space” with an up to 24 foot ceiling height due to building on a very steep hill. Despite significant efforts to insulate and dampen, my Quatro Wood CT’s in combination with the suspended floors create a tympanic effect at  very low frequencies. The techniques described in my posts above have yielded incredible measured and subjective results in my room. As I type this, my Vandersteen’s are delivering goosebumps. 

Perfect!  RV

[GdnrBob]

RTA?- Real time Attack?

 

B

[Schuesmp]

20 minutes ago, GdnrBob said:

RTA?- Real time Attack?

 

B

In this case, RTA mean Real Time Analyzer.

[Holmz]

On 6/8/2022 at 12:11 PM, Richard Vandersteen said:

The only other way would be to put the drivers in a box and zap it, correct with DSP, burn an Eprom and ship the speaker.  If you think that would be an improvement I have a bridge for sale.  That level of processing is not free nor transparent enough for the specialty market, IMO.  RV 

I am picturing the Tacoma Narrows Bridge
Maybe the EPROM could be part of a feed forward design, and then should be no feedback needed??

 

I got a DAC in the system. At first I liked it, but later in the day I was left thinking is seems a bit strident, or something without enough bass. Or maybe too much mid range.
Digital is certainly different than the TT.
I am feeding an iPad, so I guess one gets what they pay for.

Some of the music has a nice soundstage, but others have a very flat 2D presentation. Some of the recordings in the 80s are just not great. 

The DAC  is not doing any DSP. I have turned the volume down and the preamp up, which helped.
So there was likely some gain structure issue that was making it a bit grainy.

Is this how digital is? or do I just need better gear feeding it?

[GdnrBob]

1 hour ago, Holmz said:

I have turned the volume down and the preamp up,

I would do the opposite, Streamer/DAC at full volume, and adjust via preamp. It might account for the 2D presentation, as the signal is being limited. I remember Ariel at Ayre saying this is the way to do it with their DAC's.

 

B

Edited July 3, 2022 by GdnrBob

[Holmz]

13 hours ago, GdnrBob said:

I would do the opposite, Streamer/DAC at full volume, and adjust via preamp. It might account for the 2D presentation, as the signal is being limited. I remember Ariel at Ayre saying this is the way to do it with their DAC's.

 

B

I noticed that the DFAC was flashing red at -0dB.

There is some deal with delta-sigma architecture about need to stay before -6 dB (full scale).

And I noticed that the preamp was needing to be 15 dB lower when using the DAC versus the TT…  so just winged it, and set the DAC to -19dB.

[ctsooner]

What DAC are you running? What other digital products, if any, are you using with it?  What is it plugged into?  

I have outstanding digital in my system as Bob knows.  I can often still get some goosebumps (not like a full analog front end, but I don't have the major timing errors that most digital has because of the way my server, streamer and DAC all work.  They have really all lowered the ringing issues that most digital has.  I was very careful in selections, but like anything else, it wasn't cheap (but I dn't have an analog front end, so it was worth it as my only source).

 

[Holmz]

2 hours ago, ctsooner said:

What DAC are you running? What other digital products, if any, are you using with it?  What is it plugged into?  

I have outstanding digital in my system as Bob knows.  I can often still get some goosebumps (not like a full analog front end, but I don't have the major timing errors that most digital has because of the way my server, streamer and DAC all work.  They have really all lowered the ringing issues that most digital has.  I was very careful in selections, but like anything else, it wasn't cheap (but I dn't have an analog front end, so it was worth it as my only source).

 

It is an RME ADI2 Pro (DAC).
But it also does ADC (Analogue to Digital) so it is a recorder too.

No other digital gear is in the rack yet. (CD Player it getting a e new changer belt.)

Running the iPad into the DAC’s USB-B, from the iPad’s USB-C connector.
The iPad is only plugged into the DAC.

But when I use the computer it is on a power supply until a new battery arrives.

The analogue side has been an expensive upgrade...

[ctsooner]

Understand. Not familiar at all with those units.  Which I could help more.  I'm not a fan of using a computer or iPad for source though as I've had too many issues in the past and most I know are never fully happy with teh sound.  The issue are all the background programs that are run.  I had a designer give me his server that was a Mac mini. Only the necessary programs were turned on and it was never on the net. He also made a 2k (his costs) LPS for it.  My current server is Windows based and does similar.

[Richard Vandersteen]

On 6/6/2022 at 2:02 PM, GdnrBob said:

Can someone please explain a 'Passive speaker design'?

I found this, though:

https://audiojudgement.com/passive-radiator-speaker-design/

Bob

Without powered sub-woofer which is what makes them so room friendly!  RV

[GdnrBob]

22 hours ago, Richard Vandersteen said:

Without powered sub-woofer which is what makes them so room friendly!  RV

Thanks

B