Doctor's Orders-Part Two-The New Listening Room Of Steve Williams

[microstrip]

Bruce, this is indeed part of the additional studies that I'd love to see to solve the curious riddle of both the subjective and objective assessments that have been done to date. If I may summarize these succinctly:

1) Subjective: Both Steve and I found similar differences the preamp volume settings that yielded similar SPL levels with and without the Typhons in his system. We believe that a volume setting of 10 on his Lamm preamp with the Typhons in the system, provided a similar SPL to a volume setting of about 13 without the Typhons. This is with ordinary music and two listeners. It is an approximation but appears consistent.

2) Objective: When we ran a pink noise signal into the system, the difference in SPL between a "10" setting and a "13" setting was about 4dB. That is not surprising. However, when we simply left the volume control at 1 setting and connected and disconnected the Typhons, the difference in SPL was about 1db. (This seems to be confirmed by at least one other member. About the only thing you can say about an n=2 in both cases, is that its probably better than an n=1, but let's not get get carried away about accuracy and reproducibility. Like the subjective findings with 2 listeners, all we can say is that the objective results were similar between 2 totally different systems).

Therefore, we have some nominal data that suggests something other than the simple addition of the Typhons accounts for a perceptual change of about 4dB which cannot be accounted for by a 1dB objective SPL change between the presence or absence of the Typhons. As you suggest, further studies are required. To begin, I'd like to see not only amplifier output measured, but gain and sensitivity as well. The same would be true for the pre-amp and for the combined system as a whole. These are not difficult studies to do but Steve does not have resources to do them. Other members might. Caelin surely does but apparently does not wish to comment at this time (perhaps due to ongoing lab studies of his own). Suffice it to say, it is a great mystery to me and I believe the answer is probably straight forward once the proper studies are performed. What I'm pretty certain of, and to which I think we would all agree, is that I doubt the addition of the Typhons causes the pre-amp or amplifier to more than slightly double its voltage output for the same voltage input (which would be required to get a 4dB increase in the system). That would sort of be the equivalent of discovering a perpetual motion machine which simply means don't bet the ranch on this option- the answer surely lies elsewhere. But as to what the hell exactly accounts for these curious observations, I presently have no idea! I'd love to see some solid voltage measurements to get more clarity.

Marty,

I will only refer to 2) Objective. Unless we have all the details our only attitude should be checking them. How was the sound meter handled? Did you switch the power amplifiers on/off between tests? What was the exact protocol of taking the Typhon in and out? Who did it and who checked the levels? Sorry for such intimidatory questions, but they must be answered with detail - most probably the answer will be in one of the details. It would be easier if you had done a movie of the test!

 

[steve williams]

No need to turn off the amps as the Typhons are plugged into the AC duplex and runs in parallel with whatever is in the circuit

As for unplugging, I didn't realize that was such a science . I'm left handed and Marty is right handed. On the count of 3 with my left and his right hand we simultaneously unplugged the left and right channels from the AC duplex in which each amp was plugged without turning off the amps

However I do agree that there has to be something measureable

 

[edorr]

As for me. I had pink noise playing (measuring at 72db). Kept everything playing and did not touch SPL meter. Unplugged python and walked back to SPL and took another reading (72db again). Pretty controlled environment....

 

[microstrip]

No need to turn off the amps as the Typhons are plugged into the AC duplex and runs in parallel with whatever is in the circuit

As for unplugging, I didn't realize that was such a science . I'm left handed and Marty is right handed. On the count of 3 with my left and his right hand we simultaneously unplugged the left and right channels from the AC duplex in which each amp was plugged without turning off the amps

However I do agree that there has to be something measureable

So the amps were playing and the needle (or digit) of the soundmeter changed immediately when you took the Typhons off/on?

 

[steve williams]

As for me. I had pink noise playing (measuring at 72db). Kept everything playing and did not touch SPL meter. Unplugged python and walked back to SPL and took another reading (72db again). Pretty controlled environment....

So the amps were playing and the needle (or digit) of the soundmeter changed immediately when you took the Typhons off/on?

I didn't touch my SPL meter which BTW was sitting on the top of the back of my chair in the middle where my head would be

The music was placed on pause while we unplugged the Typhons. Less than one minute. The effect was noticed by us immediately but you are confusing this part of the experiment. This is where we listened with no meter and then readjusted the volume control higher until we felt it matched the SPL of that which we heard with the Typhons plugged in. This was ~4 Db

 

[microstrip]

I didn't touch my SPL meter which BTW was sitting on the top of the back of my chair in the middle where my head would be

The music was placed on pause while we unplugged the Typhons. Less than one minute. The effect was noticed by us immediately but you are confusing this part of the experiment. This is where we listened with no meter and then readjusted the volume control higher until we felt it matched the SPL of that which we heard with the Typhons plugged in. This was ~4 Db

Sorry, I was referring to the 1 dB objective difference. Was it checked with pink noise and a soundmeter or is it just my confusion? As Marty refers in 2) "That is not surprising. However, when we simply left the volume control at 1 setting and connected and disconnected the Typhons, the difference in SPL was about 1db".

 

[steve williams]

BTW, my SPL meter was set to SLOW Response and A Weighting

 

[marty]

I'm left handed and Marty is right handed.

Steve, please don't insult me by calling me "right-handed" Ok, seriously, I am left-handed, but probably used my right hand to remove the plug because I needed my left hand to balance myself on something, probably the amp. Hey, maybe that accounted for the findings!

 

[steve williams]

Sorry, I was referring to the 1 dB objective difference. Was it checked with pink noise and a soundmeter or is it just my confusion? As Marty refers in 2) "That is not surprising. However, when we simply left the volume control at 1 setting and connected and disconnected the Typhons, the difference in SPL was about 1db".

not at all. You have it correct. Checked with pink noise and a soundmeter. 1 Db difference

We all agreed that even if there were no difference how do we account for that perceptual 4 db gain

 

[Robh3606]

Hello Steve

What is the resolution on the meter? Can you read to .1 Db or 1Db? If it happened once it could be just the tolerance of the meter itself. It would not be unexpected to have a +/- 1Db tolerance as an example. All meters have some tolerance which can change with the range as well. However it it happens repeatably there is something going on. I won't even hazard to guess why. Glad you like the changes to your system.

Rob

 

[jap]

not at all. You have it correct. Checked with pink noise and a soundmeter. 1 Db difference

We all agreed that even if there were no difference how do we account for that perceptual 4 db gain

I'm not questioning your test or perceptual results, I'm just wonder how a passive PLC can increase gain.

As a Lamm owner, I'm sure you have an excellent multimeter. Did you measure AC line voltage with and without the Typhons?

BTW, here's the RadioShack SPL Meter Compensation Chart:

Frequency/Compensation
(Hz)/(dB)
10 20.5
12.5 16.5
16 11.5
20 7.5
25 5
31.5 3
40 2.5
50 1.5
63 1.5
80 1.5
100 2
125 0.5
160 -0.5
200 -0.5
250 0.5
315 -0.5
400 0
500 -0.5
630 0
800 0
1000 0
1250 0
1600 -0.5
2000 -1.5
2500 -1.5
3150 -1.5
4000 -2
5000 -2
6300 -2
8000 -2
10000 -1
12500 0.5
16000 0
20000 1

 

[steve williams]

Hello Steve

What is the resolution on the meter? Can you read to .1 Db or 1Db? If it happened once it could be just the tolerance of the meter itself. It would not be unexpected to have a +/- 1Db tolerance as an example. All meters have some tolerance which can change with the range as well. However it it happens repeatably there is something going on. I won't even hazard to guess why. Glad you like the changes to your system.

Rob

I completely agree as do every one here that we are assuming no difference and both measured 72 Db. What we are trying to determine is what gave us the need to increase my preamp by 4 Db to match what we heard with the Typhons plugged

 

[steve williams]

Jap

why can't you see the trees for the forest

Did you not read the second sentence that I wrote.....

We all agreed that even if there were no difference how do we account for that perceptual 4 db gain

That's what we are discussing

 

[jap]

Jap

why can't you see the trees for the forest

Did you not read the second sentence that I wrote.....



That's what we are discussing

Human hearing is more sensitive to some frequencies than others, as demonstrated by equal-loudness contours(Fletcher–Munson curves).

If you ran test tones at individual frequencies instead of pink noise, I think you'd find your 4 db perceptual gain.

 

[steve williams]

Let me ask the question of you guys who are more understanding of the science.......

The Typhon is a power conditioner. When it is not plugged in, could the perception of 4 Db of increase gain being necessary to make it sound the same as with the Typhons plugged in, might this come not from what the Typhons add (increase SPL) but rather what they remove (IOW lowers the sound floor). This could quite possibly explain what we were hearing.

 

[jap]

Let me ask the question of you guys who are more understanding of the science.......

The Typhon is a power conditioner. When it is not plugged in, could the perception of 4 Db of increase gain being necessary to make it sound the same as with the Typhons plugged in, might this come not from what the Typhons add (increase SPL) but rather what they remove (IOW lowers the sound floor). This could quite possibly explain what we were hearing.

Harry Pearson commenting on the Silver Circle Audio PLC:

"I am, at this point, inclined to give it a five-star rating... it's what it does to the soundfield by isolating it from distortions in the lows (centered at 60Hz) and from RF interferences in the highs. You can plug anything into one of these, including the powerful McIntosh 2301s and the CJ ART amp." - Harry Pearson, The Absolute Sound, March 2011, Issue 211.

I think your Typhons are doing the same thing in your system, giving you a cleaner lower noise sound floor that seems like increased SPLs.

I think Myles uses a SCA, maybe he can comment.

 

[Robh3606]

Hello Steve

Can you hear a noticeable drop in the noise floor? I have trouble with that only because I have 3 systems that I cannot hear noise from at any reasonable listening level from the listening position. Sure if I stick my head up against the mid and HF horns I can hear some very low level hiss. Move away and it gets lost in the backround room noise. I would imagine you can not hear the backround system noise from where you listen. If you can't hear the noise floor under normal circumstances why would a level change of the noise change the apparant loudness of the system??

I am scratching my head on this one?? I wouldn't expect any change at all except the noise level itself.

Rob

 

[steve williams]

It is dead silent in my room since I added the new equipment

 

[Robh3606]

It is dead silent in my room since I added the new equipment

Hello Steve

Did you hear noise before adding the conditioners? I would think with a dedicated room your noise floor would be significantly lower than your typical home. That would make any system noise more audible in your room than say mine as an example. I surely have higher backround noise levels especially in my basement where I have to contend with burner rumble from time to time especially when it's 10 degrees and there is a foot of snow outside. To get my basement really quiet I have to power down the computer as it is a significant noise source.

Rob

 

[steve williams]

Hello Steve

Did you hear noise before adding the conditioners? I would think with a dedicated room your noise floor would be significantly lower than your typical home. That would make any system noise more audible in your room than say mine as an example. I surely have higher backround noise levels especially in my basement where I have to contend with burner rumble from time to time especially when it's 10 degrees and there is a foot of snow outside. To get my basement really quiet I have to power down the computer as it is a significant noise source.

Rob

Like you I used to have some low level hiss but this is completely gone and the room is dead silent now