VINDICATION! Subwoofer Leading Edge Transients and John Hunter of REL’s YouTube video on setting up a REL “Six-Pack”

[Al M.]

Loss of articulation is exactly what I hear. Try Hotel California live or the interplay between Joe Morello and Gene Wright on Take Five and it's easy to hear on a reasonably resolving system.

If you think that the loss articulation comes from lack of time alignment, you should move the subs much closer to you, far in front of the main speakers, and see what happens.

Again, if that is your conviction, then having the subs aligned with the mains probably doesn't cut it.

 

[Lagonda]

I have no experience with subs that offer infinitely adjustable phase, so maybe I'm doing manually (with only the 0/180 phase switch available to me) what could be achieved with 'out of plane' placement and incremental/infinite phase adjustment, but I have never heard a system with subwoofers behind the speakers that sounds correct to me.

I agree, and i will take it one step further. I have not heard many systems with subs that sound right and homogeneous, mainly because of differences in drivers and amplification. Thank god most people are not very sensitive to phase differences. That said, i have heard a few that did the trick, but it takes more work than most are willing to put in. And in most situations it just won't sound right.

 

[musicfirst1]

If you think that the loss articulation comes from lack of time alignment, you should move the subs much closer to you, far in front of the main speakers, and see what happens.

Again, if that is your conviction, then having the subs aligned with the mains probably doesn't cut it.

Yes I agree forward of the mains sounds even better, but reflection artifacts (and my wife ) prevent it long term. (Reflection off my omni Bayz Courantes is the main reason I went from a 2x3 stack of Gibraltar G1s to a stereo pair.)

 

[x1992]

I have the CR1; it does not have a delay. I wish it did. All adjustments (except for ground switch) are referenced to frequency response.

I have no experience with subs that offer infinitely adjustable phase, so maybe I'm doing manually (with only the 0/180 phase switch available to me) what could be achieved with 'out of plane' placement and incremental/infinite phase adjustment, but I have never heard a system with subwoofers behind the speakers that sounds correct to me.

Your time goal of moving speakers is a bit different from the phase knob. The method is actually a little different as well, sine wave vs beat. They both have their limits.

 

[microstrip]

I have the CR1; it does not have a delay. I wish it did. All adjustments (except for ground switch) are referenced to frequency response.

The JL Audio subs have variable phase (0-270º) we can change delay at the sub.

 

[Al M.]

The JL Audio subs have variable phase (0-270º) we can change delay at the sub.

Fortunately they do!

 

[Al M.]

Yes I agree forward of the mains sounds even better, but reflection artifacts (and my wife ) prevent it long term. (Reflection off my omni Bayz Courantes is the main reason I went from a 2x3 stack of Gibraltar G1s to a stereo pair.)

You could also move the subs behind the listening seat. At least for the JL Audio subs, 10 feet from the main speakers would be needed for time alignment (the REL may very well differ). In my listening configuration that would move them behind me.

As for reflections, glossy surfaces unfortunately are very bad. I covered each of my subs with a rubber mat, and it makes a tremendous difference for reduction of distortion in the sound. It just doesn't look fancy. Already at ordering the subs I would have chosen a matte color instead of gloss if that had been a choice. If I had known what I know now, I would have insisted on matte, even if that custom paint had cost extra (throwing on the rubber mat might still have been an improvement though).

In general I don't understand the trend towards gloss in the high end (both speakers and gear) over the last two or three decades. It may look nice, but it's really bad for acoustic behavior. Don't the designers know that?

 

[microstrip]

In general I don't understand the trend towards gloss in the high end (both speakers and gear) over the last two or three decades. It may look nice, but it's really bad for acoustic behavior. Don't the designers know that?

Do you think that there is a significant difference at wavelengths between 17m and 1.7 mm between a gloss finish and a matte finish? IMHO we have such feeling because of the hardness of the materials we usually associate with such finish or the visual association.

IMHO in order to have some effect on sound the paint layer must be thick and be non uniform, like some types of Latex sound absorbing paints, filled with micro-spheres. Just my opinion, I am not an expert in paint acoustics!

 

[Al M.]

Do you think that there is a significant difference at wavelengths between 17m and 1.7 mm between a gloss finish and a matte finish?

Apparently there is.

IMHO we have such feeling because of the hardness of the materials we usually associate with such finish or the visual association.

That is independent of the visual effect. I even once performed an involuntary blind test, with the same result. While I still had been in the experimenting phase, I listened loudly to a track with saxophone on the right channel. I knew from listening with rubber mat on the subs next to my speakers that the sax should not sound this distorted, and was puzzled. Yet sure enough, when I looked closely (not immediately visible from the listening seat under my dim room illumination) I saw that I had forgotten to put back the rubber mat on the right sub. Then I did, and the sound cleared up as expected.

I also found that the gloss paint on the wooden window shutters in the back of my room had a detrimental effect. I really didn't think it would, because the shutters are a good number of feet behind my listening seat, and obviously much farther from the speakers, but then I finally painted them over with matte color, and the reduction in distortion was literally unbelievable. At that point, while pleasantly surprised, I was also really mad at myself because I had bought the paint half a year earlier, yet had been too lazy to do the job, thinking it wouldn't matter that much!

 

[microstrip]

Apparently there is.



That is independent of the visual effect. I even once performed an involuntary blind test, with the same result. While I still had been in the experimenting phase, I listened loudly to a track with saxophone on the right channel. I knew from listening with rubber mat on the subs next to my speakers that the sax should not sound this distorted, and was puzzled. Yet sure enough, when I looked closely (not immediately visible from the listening seat under my dim room illumination) I saw that I had forgotten to put back the rubber mat on the right sub. Then I did, and the sound cleared up as expected.

I also found that the gloss paint on the wooden window shutters in the back of my room had a detrimental effect. I really didn't think it would, because the shutters are a good number of feet behind my listening seat, and obviously much farther from the speakers, but then I finally painted them over with matte color, and the reduction in distortion was literally unbelievable. At that point, while pleasantly surprised, I was also really mad at myself because I had bought the paint half a year earlier, yet had been too lazy to do the job, thinking it wouldn't matter that much!

You are addressing adding layers of paint or rubber - something that is known to damp materials and change sound properties. I am just addressing the gloss or mate finish - you can get any of them with the same brand and type of paint.

There were many studies on the acoustic effect of paint on materials - a very different subject.

 

[musicfirst1]

I have the CR1; it does not have a delay. I wish it did. All adjustments (except for ground switch) are referenced to frequency response.



Your time goal of moving speakers is a bit different from the phase knob. The method is actually a little different as well, sine wave vs beat. They both have their limits.

Definitely two sides of the same coin. I think when it comes to this topic, very few, if any, have a complete understanding, which can be witnessed by the many many poor subwoofer implementations I've heard over the years.

 

[stehno]

Definitely two sides of the same coin. I think when it comes to this topic, very few, if any, have a complete understanding, which can be witnessed by the many many poor subwoofer implementations I've heard over the years.

Indeed. I guess that puts you all alone in your complete understanding? Congratulations.

 

[musicfirst1]

Indeed. I guess that puts you all alone in your complete understanding? Congratulations.

No, I don't include myself among the 'very few' with complete understanding of the subject, but I definitely know what I hear.

 

[stehno]

No, I don't include myself among the 'very few' with complete understanding of the subject, but I definitely know what I hear.

LOL. I know you've been focused on this endeavor for a time. IMO, this topic seems like one of high-end audio's bigger black boxes and with one of the biggest returns on investment. Would you mind sharing a couple of your more recent observations and/or discoveries?

I'd guess my biggest discovery with this subject matter is, never give up 'cuz it's out there - somewhere.

 

[Ron Resnick]

How would one connect three (3) REL subwoofers, with one on each side and one in the middle to achieve a bit of a “swarm” arrangement? Would the center subwoofer receive a L + R signal?

Does swarm work with three subwoofers, or does it require four subwoofers?

 

[MTB Vince]

How would one connect three (3) REL subwoofers, with one on each side and one in the middle to achieve a bit of a “swarm” arrangement? Would the center subwoofer receive a L + R signal?

Does swarm work with three subwoofers, or does it require four subwoofers?

All subwoofers in a "swarm" or DBA (distributed bass array) are fed a .1 summed low frequency signal.

 

[Ron Resnick]

All subwoofers in a "swarm" or DBA (distributed bass array) are fed a .1 summed low frequency signal.

Thank you. I would not want to lose left channel/right channel information.

If one were using four (4) subwoofers, why not connect two to the left channel and two to the right channel?

 

[sbo6]

I love all the theorists out there who 'prove' it can't be true but have never actually tried it before saying its inaudible. The proof is in the pudding.

How have you proved you can hear a difference within millimeters of moving subs? Have you A, B, A'd? I'll bet $100 if you move a sub ~2 mm and you A B A you can't hear the difference. Why do I say this? Because I've measured subs / mains hundreds of times including minor movements which made no measurable difference (SPL spectrograph, waterfall) and no audible difference. And I did A B A. The wavelengths are so long that millimeters simply don't matter. Phase, xover freq, polarity, driver positioning, and significant subwoofer placement does.

 

[musicfirst1]

How would one connect three (3) REL subwoofers, with one on each side and one in the middle to achieve a bit of a “swarm” arrangement? Would the center subwoofer receive a L + R signal?

Does swarm work with three subwoofers, or does it require four subwoofers?

My approach would be:

Subs must be connected only with high level outputs, when available.
(For me, low level feeds (Typically from the preamp or the HT processor) to the subwoofers are a non starter. I have tried low level inputs directly from the preamplifier with no success.

For the left and right channel subs: -
Connect red and yellow wires together, each to the respective 'hot' binding post on the left and right channel of your amplifier(s)

For the centre channel sub:-
Connect the red wire to the 'hot' binding post of the right channel of your amplifier. (this binding post will now have a total of three subwoofer wires connected; two red and one yellow, along with the main speaker wires.)
Now connect the yellow wire to the 'hot' binding post of the left channel of your amplifier. (This binding post will now have two yellow and one red subwoofer wires connected.

The corresponding ground wires can initially be connected to the corresponding negative binding posts. If hum ensues, try various combinations of floating and grounding.

I see the configuration described here as more of L-C-R sub configuration as opposed to a 'swarm'.

I feel a subwoofer swarm, properly configured, is all about finding the best in-room low frequency extension by placing multiple subs at locations where the room response is naturally reinforced.
While this is a laudable objective, my experience is that Swarms never offer anywhere close to ideal integration with the main speakers. To my ears, this lack of integration is easily heard with almost any source and configuration: two channel, HT 5.x, 7.x, 9.x etc., whether fed a homogenized x. 1 HT signal or a full two channel L and/or R signal.

During my many months, indeed stretching into many years of experimenting with trying as many as six simultsneous REL Gibraltar G1 subs in virtually every, and I do mean EVERY conceivable floor based configuration one can conceive (1x6 swarm at the room nodes, 3 x 2 high pairs (connected as described above) at the room corners and the center of the back wall, and at incremental 6" positions towards the listening chair well out past the plane of the main speakers.

 

[treitz3]

Hello, sbo6 and good evening to you.

How can one "prove" what they hear...or even perceive to hear? Even if they could, how could you "prove" otherwise?

Measurements are but only one aspect of the reproductive effort. A very small move with mains can make a dramatic change to the perceived effort of a system. A height change with a sub or even a small location change can make a big difference within a system.

This is all room dependent, system and gear/resolution dependent, of course. Mostly room dependent but still.....how can you challenge something you are not privvy too?

Tom