My monitor/subwoofer system

[Tango]

View attachment 89501

Adjusting phase on the subwoofers: Better mid-bass

Upon Peter A.’s last visit, we played Kenny Burrell’s “Midnight Blue”. Peter commented that there was quite a bit of bass in the reproduction of this recording on my system.

I then decided to demonstrate at the beginning of track 1, ”Chitlins Con Carne” (see above), how much of the bass came from the monitors alone, so I turned off the subs (easily done by a switch on the preamp that decides about the outputs). To both our surprise there was more bass without the subs! Repeated switching back and forth between the outputs confirmed the effect beyond a doubt.

This was weird. I had noticed before that on one track of Miles Davis’ "Kind of Blue" there was cancellation of the bass by the subwoofers, but I had not spent much thought on that, also because the cancellation effect there was actually positive (removal of bloating of one bass note by an apparent room node).

When in January 2018 I was about to make a decision on which subwoofers to purchase, Ian (Madfloyd) strongly recommended to me that I should buy JL Audio subwoofers, because of their high adjustability, which goes considerably beyond what many other subs had to offer, including my old REL Storm III. He had experience with bass cancellations, especially when it came to employment of two subwoofers (a single sub was less critical in his experience). I am very happy that I followed his great advice. This is not just because of the adjustability – the E.L.F. (extreme low frequency) attenuation was a lifesaver in my medium-sized room – but simply because of the great sound, enabled by the sheer speed and agility of the reaction of the subs to the music. Ian had highlighted the latter in his recommendation as well.

The continuous phase adjustment, which is also offered on the JL Audio subs, would in Ian’s opinion be useful to attack bass cancellations. I had tried it once before, but only one a single track, and could not hear a meaningful difference. Yet given the new experience, I decided to explore the cancellation phenomenon further. So the day after Peter’s visit I went to work.

I started with the ”Chitlins Con Carne” track on the Kenny Burrell album. Turning up the phase on one sub from 0 degrees to 45 degrees and beyond did dramatically change the amount of bass heard on the track! I couldn’t believe it. Then I tried what happened if I would increase the phase on both subs. That also worked. After checking some more music, finally I settled on 45 degrees phase on both subs, because going higher either didn't lead to further improvement or actually led to bloating of bass.

At the same time I received my ZenWave Clear Bass power cables for the system from DaveC, including for the subwoofers. These improved the situation even further, because while now I had much more midbass than before at the same volume setting of the subs, the bass control improved with the new power cables.

I was simply delighted about the amount of mid-bass, which was new to my system and further filled the mid-bass hole between the monitors and the deep bass of the subs, a hole that had already gotten much smaller over the years than it used to be in the beginning, especially with my old monitor/subwoofer system.

Yet more critical listening revealed that there was still some bloating at certain frequencies, and I decided to explore further refinement of the phase adjustment.

I did the same with my horn subs. Try playing with many different songs or music. Eventually you will find a toss between phase x or phase y. Some recording y might be better than x vice versa.

 

[Al M.]

Al, have you measured your room? REW is much more effective than using Kind Of Blue to determine where you have room modes. You can borrow my USB mic if interested.

Thanks, Bazelio. No, I haven't. Since I do not use digital room correction, that knowledge would not easily translate into improvement. I am now also quite satisfied with the bass, and do not experience major non-linearities. I would have to go back and check how that track from "Kind of Blue" sounds now.

 

[Al M.]

I did the same with my horn subs. Try playing with many different songs or music. Eventually you will find a toss between phase x or phase y. Some recording y might be better than x vice versa.

I have played a large variety of music now, and am very happy with the overall result. I have not changed my settings in a while, and do not plan to do so again any time soon. The bass now suits my tastes very well.

Of course, bass is never perfect on all recordings, and that holds for reproduction on any system, not just mine.

Just the last few days I listened to a great piece by Hungarian composer Sandor Veress for an ensemble for 12 strings, the recording of which has a few passages with major issues regarding the reproduction of the low strings (it is recorded by some radio broadcast company). In that case, I simply turn off the subs with the output switch on my preamp; the problems are still audible to some extent with just the monitors.

Yet such extreme cases are rare. For the few anemic rock recordings that I have I simply can boost the bass with the very transparent tone control on my preamp, but most rock sounds fine too. Usually (about 99 % of the time) the tone control on the preamp is untouched, or rather, by-passed. I do not use the controls on the subwoofers any more between recordings. It would be impractical to do so anyway; the front grilles which also cover the controls are on again. The philosophy for the subs is now set and forget. And forget is what I have done the last few weeks.

 

[microstrip]

(...) Of course, bass is never perfect on all recordings, and that holds for reproduction on any system, not just mine. (...)

Surely - it is also due in part to the lack of standard for bass performance and level in recording studios. And it is not only bass that is not perfect in recordings - treble is also variable. In some aspect we optimize our systems also to become tolerant to such differences.

A couple of sessions with Mark Levinson manipulating his Audio Palette six rotary controls showed me another perspective of stereo sound reproduction - if we could afford to "correct" all recordings to match our systems audiophile life would be much easier. But then you spend 90% of your time "correcting" and 10% listening.

 

[bazelio]

Thanks, Bazelio. No, I haven't. Since I do not use digital room correction, that knowledge would not easily translate into improvement. I am now also quite satisfied with the bass, and do not experience major non-linearities. I would have to go back and check how that track from "Kind of Blue" sounds now.

You would not necessarily need eq. But since you have room treatment, you could use REW to place/adjust new or existing treatment. At the end of the day, it can never hurt to know how your room measures. Also, you can move the mic around the room and measure at different reflection points.

 

[microstrip]

(...) Yet more critical listening revealed that there was still some bloating at certain frequencies, and I decided to explore further refinement of the phase adjustment.

Yes, phase is critical. I also found that the damping control of the CR1 JLAudio crossover could operate miracles matching the JL Audio subwoofer to the main speakers. Unfortunately in order to use it fully we need to pass the full signal through the solid state crossover - although some positive action can be taken just using the low frequency channel of it. The choice of mode will depend on user priorities.

 

[Ron Resnick]

Thank you for these very interesting reports, Al!

You must've been pretty puzzled when you turned the subwoofers off and you heard more bass!

 

[KeithR]

Al, have you measured your room? REW is much more effective than using Kind Of Blue to determine where you have room modes. You can borrow my USB mic if interested.

Or even better hire someone to setup his speakers and subs properly.

 

[Al M.]

Thank you for these very interesting reports, Al!

You must've been pretty puzzled when you turned the subwoofers off and you heard more bass!

You're welcome, Ron.

Yes, that was puzzling. But Ian, who has much more experience with this, had warned me that you can get bass cancellation with subs, so I had an idea what might be the problem right away.

As I reported, I once did explore the phase issue, but not to a sufficient extent, and frankly, had not taken the bass cancellation issue seriously, because I had been quite satisfied with my bass (and I had heard a number of positive comments on it from others). Of course, once you hear how it can be better, it's different.

The vanishing of mid-bass on the "Chitlins con Carne" track was quite dramatic. I had not heard such an effect the many other times I had turned off the subs, just for experimenting, on on other tracks (the "Kind of Blue" track that I mentioned appeared to be an exception as well).

 

[Al M.]

Update on power cables

Now I have three ZenWave Pl-11 power cables (2 meter, FI-50 NCF plug, $ 1,348) in my system; one of them is still demo, but my own third cable is ordered. The rest is ZenWave Clear Bass power cables ($ 375 for 2 meter cable), for the two subwoofers, CD transport and re-clocker between transport and DAC. ZenWave is owned by WBF poster DaveC.

The ZenWave Clear Bass cables on their own are already fantastic. On this thread (post #169) is my initial report:

Audiophile power cords vs. the cables in your walls

Al, do you mean breaker box? Or do you really still have fuses? Both the breaker box and all the fuses of each audio equipment! when I upgraded the inwall PC, I used the Siemens of which the audio engineer considered a decent one but he advised me that I should upgrade the breaker box an...

www.whatsbestforum.com

While the Clear Bass cable is terrific value for the money, and at least on my power amp the step from stock power cable to Clear Bass cable was considerably larger than the step from Clear Bass cable to PL-11 cable, the PL-11 is still better, and to me very much worth the money.

Here is my impression on the power amp that I have posted elsewhere before:

While for the most part they "sound" identical, the PL-11 on the power amp sounds calmer than the Clear Bass, at the same level of vividness and dynamics. To me it's a subtle but important difference. Also, the PL-11 sounds slightly more "organized" when the complexity increases.

My impression of the PL-11 on the preamp:

On the preamp the PL-11 plays cleaner than the Clear Bass, with less distortion, and at the same time with a more vibrant, expressive, lively tone. This is really obvious on, for example, a string quartet on period instruments (a quartet by Eybler, a genius contemporary and friend of Mozart, with the Eybler Quartet). The PL-11 also features a slightly better bass timbre (Pink Floyd, Dark Side of the Moon).

***

Recently I got the second ZenWave PL-11 power cable for my preamp/amp combo, but instead of just putting it there and right away sending back the PL-11 demo that I still had from DaveC, I kept the demo on the amp and put the new PL-11 on the DAC, now having three PL-11 in the system (DAC, preamp, amp). As mentioned above, CD transport, reclocker and the two subs are on Clear Bass cables.

Below is my report on a comparison PL-11 vs Clear Bass on my Yggdrasil Analog 2 DAC (Yggdrasil OG), prompting me to order a third PL-11 power cable. It also addresses further improvements in bass performance on Pink Floyd's "The Wall", a report of which I hinted was forthcoming in a post from yesterday.

Note: Standing apart from the comparison PL-11 vs Clear Bass on the DAC, the Clear Bass on the subwoofers already had enhanced bass control there significantly.

***

As he did with my first one, DaveC burned in the second PL-11 cable before sending. It took 2 or 3 days for the new, already burned in PL-11 on the DAC to stabilize; at first the bass was slightly weaker before regaining full power.

With three PL-11 cables in the system -- preamp, amp and DAC -- I can now clearly hear what a difference on the DAC it makes to go from Clear Bass to PL-11, and it is significant. All below observations regarding the PL-11 vs Clear Bass on the DAC have been double checked by going back and forth between the two cables.

First, there is better bass control. I had already been very satisfied with the quality of my bass, but this takes it one step further. On Pink Floyd's "Hey You" (The Wall) there is really saturated, "fat" mid-bass on drums/bass. With the Clear Bass there is slight blurring and bloating on some drum figures, which almost completely goes away with the PL-11. On Pink Floyd's "Brain Damage" (Dark Side of the Moon) the whole bass landscape in the chorus (after around 1 minute) is a bit blurry to begin with, with long bass notes/drones embedded in the foundation. Yet with the PL-11 the landscape clears up dramatically, with a good avoidance of bloating even though there are still minor remnants. On the next track, "Eclipse", the saturated drums are more controlled with the PL-11; with the Clear Bass they slightly blur and intrude into the cleanness of the rest of the presentation. In Pink Floyd's "Mother" (The Wall) the voice of Roger Waters has some slight bloat on the low end of his range, perhaps as an artifact of close miking (I usually don't hear any such blurring on classical recordings of baritone or bass voice, and there are no problems elsewhere on the The Wall album). The bloat goes away by turning off the subwoofers. Yet with subwoofers on, it is very much diminished with the PL-11 on the DAC, to an extent that I probably would not have noticed it in such a manner that it prompted me to perform the sub on/sub off experiment in the first place, when the Clear Bass cable was on the DAC. The bass guitar and drums later in the track again are cleaner with the PL-11, and do not muddy up the rest of the soundscape. On some bass textures throughout "The Wall" album, there is also slightly more slam with the PL-11.

Second, massed violins are improved. My reference go-to recording for this is currently Haydn's Paris Symphonies with the Academy of St. Martin in the Fields under Neville Marriner, in a 1989 digital transfer to CD from the Seventies analog recordings published on the MHS label (Musical Heritage Society; licensed from Philips Classics). Myself and Ian both had already admired the beautiful silky string texture on my system. If anything, with the PL-11 the string textures are yet slightly more silky, less electronic sounding, compared to the Clear Bass on the DAC (putting just the Clear Bass on the amp, not the DAC, preamp or other components which still ran stock cable, initially had, a few months ago, made a first huge leap forward in revealing a silky string texture, see the link above). Also, when the music gets louder and denser, there is less "peaky" upper midrange/treble distortion with the PL-11 cable on the DAC; the music retains composure and cleanness. It had already sounded very clean with the Clear Bass on the DAC, but this takes it still one step further.

Of course, I could do more comparisons, yet just these are really important improvements, and I have not noticed any drawbacks with the PL-11 on the DAC instead of the Clear Bass cable. It took me a while to zoom in on the described improvements, but with double and triple checking going back and forth the eventually unmistakable differences were fleshed out clearly.

As I said, based on the observations I have ordered a third PL-11 cable from DaveC.

***

I should add that in the meantime I have revisited a few recordings the sound of which I had been very familiar with using stock power cables in the system. The experience confirmed that all my ZenWave power cables do nothing strange to tonal balance and timbre; they just improve the sound without introducing an artificial imprint on their own. I am very happy with my decision to go all in on ZenWave.

 

[Al M.]

Furutech e-TP609 NCF 6-way power distributor

Website:

e-TP609 NCF | FURUTECH

Features Axial Locking System [USA Patent No.7,648,391 / JP Patent No. 4616208] and EMI-Absorbing Formula GC-303 <br /> <br /> e-TP609 NCF - Rated 15A/125V AC (NEMA version)<br /> e-TP609E NCF - Rated 10A/250V AC (Schuko version)<br />

www.furutech.com

This is an update on a change in my system a few months ago:

First impressions:

The 609 made an immediate impression. The sound is cleaner, and not by a bit. Of course, I have to go back and double check, but the difference seems too obvious to be a mistake in judgment. The system simply shouts less. Also, bass may be even tighter, but I'll have to let the new ZenWave PL-11 settle on the DAC for a few days until I can make a final assessment about the nature of the bass. From the initial impressions the 609 seems a winner.

Above are a few pictures. The white cables out of the 609 are to the isolation transformers (out of which ZenWave power cords go to the digital front end components); the ZenWave PL-11 cords (black-white pattern) out of the 609 go to the preamp and amp, the ZenWave Clear Bass cords (black) out of the 609 go to the subs. From the distributor a ZenWave Clear Bass cord goes to the power outlet. The distributor is on a concrete tile (Home Depot, $2.18).

(The distributor replaced 2 green extension cords with 3-way plugs; they are still visible in the pictures but now entirely removed.)

Second round of impressions, a few days later:

The verdict is in. I did the direct comparison, and my first impressions were spot on. The sound is considerably cleaner, the system screams less at me (e.g., vocals, high register of Hammond organ). I find the sound now so natural and effortless, it often reminds me of good analog. I think the problem with digital is electric noise, and the Furutech also helps with that. Once you get rid of the electric noise, digital sounds as it always should have.

Bass is in fact tighter, better controlled and more even. For example, the lowest note of the bass guitar line in Pink Floyd's "Money" from Dark Side of the Moon is pretty even with the rest of the bass line, whereas without the Furutech the lowest note sticks out. The kick drum also sounds more controlled, the overall bass envelope on the track is less 'dirty'. The bass (low mid-bass) is also stronger in some instances, e.g. on some tracks of Pink Floyd's The Wall.

After all the power changes (power cords and distributor), the clean calmness from which the sound arises, combined with very lively musical energy is great. I am very pleased.

***

Something that I also noticed is more natural dynamic behavior. I posted this some time ago on another thread, after I already had the 609 distributor:

"Indeed, a hardening of sound, or sudden transients with overly hard edges, can sometimes be mistaken as "dynamics".

"With the latest changes to power delivery in my system, which overall are a big step forward, I have noticed that on some musical material a previously perceived 'exciting edge' that led to an enhanced perception of dynamics has been smoothed off. Yet I have found out that this is actually a good thing, a removal of artifact (an artifact that is not found in unamplified live music either). On the other hand, a few tests on critical material confirmed that dynamics, both macro and micro, can be just as explosive as before. In other words, the system still reproduces true dynamics of music, but has stripped away the fake ones."

Orchestral strings have become so refined, smooth and airy, and even on the onset of sudden louder notes unnatural hardness is gone -- it sounds so much more like I am used to from the concert hall. Free and effortless in such passages. I had already swooned over the string sound after the first set of ZenWave power cords, but now with everything in place *and* the Furutech 609 it is quite remarkable. The subtle depth of timbre on some passages is much closer to the live experience too.

The relaxed lack of hardness of strings in such louder passages indeed seems to "smooth" the dynamics, but again, this is really just removing an 'exciting' artifact that does not exist in classical live music. Yet brass attacks can be just as explosive and with "bite" as they have been before -- as it should be -- so there is no artificial smoothing of the entire reproduction either. Those brass attacks also sound more effortless, which again is more in line with live music.

***

The ZenWave power cords and the Furutech 609 distributor all have rhodium plating on their connectors. DaveC, from whom I bought the distributor, told me that the result that I hear is likely a combination of the receptacles and plugs using the same materials, the NCF and GC-303 treatments on the distributor, and the damping provided by the chassis and lateral locking system.

 

[PeterA]

Sounds like great progress Al. Congratulations. I like the references to “natural dynamics” and the system sounding “natural and effortlessness.” Getting rid of what are perceived to be enhanced leading edges while retaining dynamics is always a good thing.

 

[bazelio]

Al, if it's even possible and he's willing, do try to compare this Furutech product to Peter's homemade Hubble outlet box. I think you'll be surprised.

 

[PeterA]

Al, if it's even possible and he's willing, do try to compare this Furutech product to Peter's homemade Hubble outlet box. I think you'll be surprised.

Brian, I made four from Home Depot parts. They just have one Hubble receptacle in each and are wired to the panel. What exactly are you proposing? Can you describe how to hook up Al’s box in my system and how you would conduct such a comparison?

What do you suspect we would hear and who would be surprised?

 

[spiritofmusic]

Sounds like great progress Al. Congratulations. I like the references to “natural dynamics” and the system sounding “natural and effortlessness.” Getting rid of what are perceived to be enhanced leading edges while retaining dynamics is always a good thing.

Maybe Al can describe what he means by "natural". I mean, natural is as natural does. But what IS natural? And what DOES it do?

 

[Al M.]

Maybe Al can describe what he means by "natural". I mean, natural is as natural does. But what IS natural? And what DOES it do?

Natural = realistic. That is, realistic compared to the reference of live unamplified music. If you don't like the word "natural", fill in "realistic".

 

[bazelio]

Brian, I made four from Home Depot parts. They just have one Hubble receptacle in each and are wired to the panel. What exactly are you proposing? Can you describe how to hook up Al’s box in my system and how you would conduct such a comparison?

What do you suspect we would hear and who would be surprised?

I was proposing you take your boxes to Al's. Obviously not possible if they're direct wired. Well, possible, but not convenient.

 

[PeterA]

I was proposing you take your boxes to Al's. Obviously not possible if they're direct wired. Well, possible, but not convenient.

I thought that was rather obvious, which is why I thought you were suggesting Al bring over his portable box with power cord to my place. I still don’t understand how you would propose to do such an experiment and what you would expect to hear and who you think would be surprised?

One could insert the Furutech box via Al’s Zenwave PC into my home built outlets to see if the combination is transparent and simply removes noise. Have you ever done such an experiment?

 

[bazelio]

I thought that was rather obvious, which is why I thought you were suggesting Al bring over his portable box with power cord to my place. I still don’t understand how you would propose to do such an experiment and what you would expect to hear and who you think would be surprised?

One could insert the Furutech box via Al’s Zenwave PC into my home built outlets to see if the combination is transparent and simply removes noise. Have you ever done such an experiment?

No it wasn't obvious as I'm not following every detail of your voluminous system thread, Peter. I know about your Hubbel receptacles and the suggestion is really simple in concept... and go figure as we're now several paragraphs in to what should have been a couple sentences. But if there's a way for Al to compare a Home Depot Hubbel box (yours or otherwise!) in his system to the, what, $1k+ (?) Furutech box, then I think it's worthwhile. I replaced Furutech outlets with Hubbel myself because the result of comparison was eye-opening. I also don't buy the stuff about like metals being advantageous, e.g. mixing rhodium and gold or nickel contacts, or what have you. But that's secondary.

 

[Al M.]

But if there's a way for Al to compare a Home Depot Hubbel box (yours or otherwise!) in his system to the, what, $1k+ (?) Furutech box, then I think it's worthwhile. I replaced Furutech outlets with Hubbel myself because the result of comparison was eye-opening.

What were your findings? What metal (metal plating) were the power cord plugs?