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Post by boomzilla on Jul 1, 2020 19:41:18 GMT -5
A tale of hum... So I rearranged and simplified my audio rack today - dressed all power cords away from all signal interconnects. Ensured that there were no physical loops in the wiring to pick up hum. Verified that there were at least 8 inches of clearance between power cords and signal interconnects (the maximum distance allowed by the geometry of my audio rack). Plugged each and every device into the same power distribution strip. And then fired up the system. Result: Loud hum from BOTH speakers. Interconnects, to this point were all RCA. So I used a converter cable at the final component to go from RCA to XLR cables. Ran XLR from the centered equipment rack to the power amps and subs (about nine feet away on each side), and fired up the system again. Result: TINY residual hum (had to be within a foot of the speakers to hear it). No other change anywhere in the system - just went from RCA to XLR interconnects. Will this work in every case? I seriously doubt it. Did it work for me today? You betcha! Who am I to blow against the wind? Boomzilla
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Post by boomzilla on Jul 2, 2020 5:29:10 GMT -5
Interesting: passionforsound.lachlanfennen.com/massive-usb-comparison-test/But I'd also add that the shorter the USB cable, generally, the better I think it sounds. And yeah - I understand intellectually that digits are digits, that either the digits are received or they aren't (there's no in between), and that only jitter can affect the data stream, and even then only if it's beyond the limits of the buffer to reclock. But I hear what I hear, and I'll state the following emphatically: 1. In my system, having the source computer located on the equipment rack with USB connection to the DAC sounds better than a remote computer connected to the listening room via Ethernet. Better how? With Ethernet, I got occasional dropouts in the sound, and sometimes a midrange roughness. 2. In my system, running a shorter USB cable between components rather than a longer one generally sounds better. Why? I've no idea. Better how? The sound has more harmonics, warmth, and sounds "less digital." A friend of mine says "it sounds wetter." 3. In my system, the brand and type (and cost) of a USB cable is generally inaudible. Length seems to matter more than the diff between a generic printer cable and an Audioquest Carbon. I've got a variety & have tried them all. 4. Your experience may vary from mine. (I've friends who swear by one brand or another of USB cable). 5. Just in passing, I'll mention that I DON'T have any jitter-reduction devices in my system. The last time I tried an Audioquest Jitterbug (with one of their Dragonfly DACs), I heard no difference. 6. Also, just in passing, I see a LOT of ex-analog "tweakers" trying to apply analog "tweak thinking" to digital systems. I question the efficacy of their tweaks, but I hear that their systems do sound spectacular. In other words, I question their explanations of WHY their tweaks sound good, but I also admit that their tweaks DO sound good. So something's going on there, but I've no idea what.
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Post by garbulky on Jul 2, 2020 9:08:16 GMT -5
Chances are if the USB is different, then either it's variations in one's own perception or the dac isn't all that great with USB. The only dac I've heard so far where I thought the USB was fine was the Mytek Liberty DAC. USB asynchronous communication has less jitter than coax and optical because it is asynchronous in nature. But at the levels present in dacs, jitter is likely very inaudible.
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Post by fbczar on Jul 2, 2020 9:45:13 GMT -5
Interesting: passionforsound.lachlanfennen.com/massive-usb-comparison-test/But I'd also add that the shorter the USB cable, generally, the better I think it sounds. And yeah - I understand intellectually that digits are digits, that either the digits are received or they aren't (there's no in between), and that only jitter can affect the data stream, and even then only if it's beyond the limits of the buffer to reclock. But I hear what I hear, and I'll state the following emphatically: 1. In my system, having the source computer located on the equipment rack with USB connection to the DAC sounds better than a remote computer connected to the listening room via Ethernet. Better how? With Ethernet, I got occasional dropouts in the sound, and sometimes a midrange roughness. 2. In my system, running a shorter USB cable between components rather than a longer one generally sounds better. Why? I've no idea. Better how? The sound has more harmonics, warmth, and sounds "less digital." A friend of mine says "it sounds wetter." 3. In my system, the brand and type (and cost) of a USB cable is generally inaudible. Length seems to matter more than the diff between a generic printer cable and an Audioquest Carbon. I've got a variety & have tried them all. 4. Your experience may vary from mine. (I've friends who swear by one brand or another of USB cable). 5. Just in passing, I'll mention that I DON'T have any jitter-reduction devices in my system. The last time I tried an Audioquest Jitterbug (with one of their Dragonfly DACs), I heard no difference. 6. Also, just in passing, I see a LOT of ex-analog "tweakers" trying to apply analog "tweak thinking" to digital systems. I question the efficacy of their tweaks, but I hear that their systems do sound spectacular. In other words, I question their explanations of WHY their tweaks sound good, but I also admit that their tweaks DO sound good. So something's going on there, but I've no idea what. Boom, I believe the differences you hear relate to the electrical noise in the system. Jitter has nothing to do with it. You may remember that the folks who manufacture the microRendu and UltraRendu recommend extremely short USB connectors. So USB cables and outputs, power supplies and the noise generated by the computer used to render your music all matter.
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Post by boomzilla on Jul 2, 2020 15:39:35 GMT -5
Boom, I believe the differences you hear relate to the electrical noise in the system. Jitter has nothing to do with it. You may remember that the folks who manufacture the microRendu and UltraRendu recommend extremely short USB connectors. So USB cables and outputs, power supplies and the noise generated by the computer used to render your music all matter. Curious - my audio amigo who recommended the short USB cables also said that power cables made audible differences - but ONLY on his server computer. Tis a mystery to me...
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Post by boomzilla on Jul 4, 2020 4:44:44 GMT -5
I'd also note that once I put shorter USB cables in the system, that for the first time I've been able to hear the midrange "wolf tones" distinctly as opposed to just a midrange blur at those frequencies. Coincidence?
So how short are we talking about? The USB-2 cable from the external HDD to the Mac Mini is about 6-inches long, and the USB-3 cable from the Mac Mini to the DAC is a half-meter long Audioquest Carbon. If I could find someone that custom made USB cables, I could probably reduce the half-meter job by a few inches. I already have in my spares drawer some 1-foot long (305mm) USB-2 cables, but they're just slightly too short to reach from the Mac Mini to the DAC. I may rearrange the components to see If I can substitute the 305mm for at the current 500mm one.
If I do that, however, I may have to also change the RCA interconnect lengths from the DAC to the passive volume control. Or else use a "sub-shelf" in the equipment rack to allow for different spacing...
Is it worth the work to rearrange the equipment rack again? Previously, I'd have said no, but the startling increase in clarity that I've just achieved with the shorter USB cables has me wondering...
So may I encourage youse guys to try this experiment as well? Short USB cables are available on Amazon for between $7 and $12, and if you're willing to go to the work to rearrange your gear, I'd be most interested to see if you get the benefits that I have. Note that I haven't tried this with Optical TOSLINK nor have I tried it with a preamp with integrated DAC; my gear is all discreet components - USB Server HDD / Server Computer / USB DAC. Would the same benefits occur with, for example, a shorter coaxial SP/DIF cable? I have no idea.
Thanks - Boom
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Post by boomzilla on Jul 5, 2020 8:01:07 GMT -5
The value of anchoring speakers.
For the past year (?), I've had my Emotiva T2 speakers on rollers so I could easily experiment with positioning. When I wanted to listen, I'd roll them out into the room and when I was finished, I'd roll them back against the wall. The sound was good, but without too much bass - particularly when the speakers were further out into the room. Since I had subwoofers, I didn't give it much thought.
Well I finally found a spot that I thought was the optimal mix of imaging and bass response (the both of those aspects were only slightly compromised from their individual "best" positions). And having found that spot, I decided to remove the rollers. And while I was at it, I got a pair of outriggers for peanuts from Dayton Audio and installed them at the same time. The results are somewhat startling.
I had on hand some "industrial" rubber feet intended for maybe workbenches, warehouse shelves, or stacks of stage monitors. To install them on the Dayton outriggers, I had to drill out the internal metal washer on each of the rubber feet to fit the M8-1.25 size threads on the Daytons. But with a heavy-duty drill, and some famous Boomzilla brute-force and awkwardness, I got the job done. The combination of the outriggers and the "monster feet" lift the T2 speakers by about two inches.
So what did this do to the sound? First, it added about a half an octave to the bass response. On the rollers, the T2s sounded like they began rolling off between 45 and 40 Hz. Now, it sounds like I'm hearing some solid low-30s from the same speakers with the same amps. Curious! If I had carpeted concrete floors, I'd have used the spikes that were included with the Dayton outriggers, and I may eventually try that since I have some "spike cups" made to protect the wooden floors. But for the time being, I'm enjoying (really enjoying) the newfound bass of my T2s. I believe (though I could be wrong) that the very HARD rubber feet I've got on there are doing an effective job of anchoring the speakers as is. The feet I'm using are about twice as hard as the rubber feet supplied by Emotiva, and also twice as large. I think that I could live with the T2s by themselves (no subs) if I wanted to. Yes, the subs still add something, but not nearly as much, now.
I'd also note that my subs are also on stands with rollers. I'm wondering how much the bass curves are being affected by the rollers? I'd expect the rollers to have even MORE effect on the subwoofers than they did on the T2s because of the lower frequencies. Is the measured dip from my subs not from the room or even from the subs themselves, but rather from a resonance frequency where the sub drivers are pushing the rollers around?
So to summarize - my speaker rollers were detrimental to the sound and I didn't even know it until I removed the rollers. YMMV
Boom
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Post by foggy1956 on Jul 5, 2020 9:57:39 GMT -5
The value of anchoring speakers. For the past year (?), I've had my Emotiva T2 speakers on rollers so I could easily experiment with positioning. When I wanted to listen, I'd roll them out into the room and when I was finished, I'd roll them back against the wall. The sound was good, but without too much bass - particularly when the speakers were further out into the room. Since I had subwoofers, I didn't give it much thought. Well I finally found a spot that I thought was the optimal mix of imaging and bass response (the both of those aspects were only slightly compromised from their individual "best" positions). And having found that spot, I decided to remove the rollers. And while I was at it, I got a pair of outriggers for peanuts from Dayton Audio and installed them at the same time. The results are somewhat startling. I had on hand some "industrial" rubber feet intended for maybe workbenches, warehouse shelves, or stacks of stage monitors. To install them on the Dayton outriggers, I had to drill out the internal metal washer on each of the rubber feet to fit the M8-1.25 size threads on the Daytons. But with a heavy-duty drill, and some famous Boomzilla brute-force and awkwardness, I got the job done. The combination of the outriggers and the "monster feet" lift the T2 speakers by about two inches. So what did this do to the sound? First, it added about a half an octave to the bass response. On the rollers, the T2s sounded like they began rolling off between 45 and 40 Hz. Now, it sounds like I'm hearing some solid low-30s from the same speakers with the same amps. Curious! If I had carpeted concrete floors, I'd have used the spikes that were included with the Dayton outriggers, and I may eventually try that since I have some "spike cups" made to protect the wooden floors. But for the time being, I'm enjoying (really enjoying) the newfound bass of my T2s. I believe (though I could be wrong) that the very HARD rubber feet I've got on there are doing an effective job of anchoring the speakers as is. The feet I'm using are about twice as hard as the rubber feet supplied by Emotiva, and also twice as large. I think that I could live with the T2s by themselves (no subs) if I wanted to. Yes, the subs still add something, but not nearly as much, now. I'd also note that my subs are also on stands with rollers. I'm wondering how much the bass curves are being affected by the rollers? I'd expect the rollers to have even MORE effect on the subwoofers than they did on the T2s because of the lower frequencies. Is the measured dip from my subs not from the room or even from the subs themselves, but rather from a resonance frequency where the sub drivers are pushing the rollers around? So to summarize - my speaker rollers were detrimental to the sound and I didn't even know it until I removed the rollers. YMMV Boom Did you run an REW freq sweep?
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Post by monkumonku on Jul 5, 2020 10:16:03 GMT -5
The value of anchoring speakers. For the past year (?), I've had my Emotiva T2 speakers on rollers so I could easily experiment with positioning. When I wanted to listen, I'd roll them out into the room and when I was finished, I'd roll them back against the wall. The sound was good, but without too much bass - particularly when the speakers were further out into the room. Since I had subwoofers, I didn't give it much thought. Well I finally found a spot that I thought was the optimal mix of imaging and bass response (the both of those aspects were only slightly compromised from their individual "best" positions). And having found that spot, I decided to remove the rollers. And while I was at it, I got a pair of outriggers for peanuts from Dayton Audio and installed them at the same time. The results are somewhat startling. I had on hand some "industrial" rubber feet intended for maybe workbenches, warehouse shelves, or stacks of stage monitors. To install them on the Dayton outriggers, I had to drill out the internal metal washer on each of the rubber feet to fit the M8-1.25 size threads on the Daytons. But with a heavy-duty drill, and some famous Boomzilla brute-force and awkwardness, I got the job done. The combination of the outriggers and the "monster feet" lift the T2 speakers by about two inches. So what did this do to the sound? First, it added about a half an octave to the bass response. On the rollers, the T2s sounded like they began rolling off between 45 and 40 Hz. Now, it sounds like I'm hearing some solid low-30s from the same speakers with the same amps. Curious! If I had carpeted concrete floors, I'd have used the spikes that were included with the Dayton outriggers, and I may eventually try that since I have some "spike cups" made to protect the wooden floors. But for the time being, I'm enjoying (really enjoying) the newfound bass of my T2s. I believe (though I could be wrong) that the very HARD rubber feet I've got on there are doing an effective job of anchoring the speakers as is. The feet I'm using are about twice as hard as the rubber feet supplied by Emotiva, and also twice as large. I think that I could live with the T2s by themselves (no subs) if I wanted to. Yes, the subs still add something, but not nearly as much, now. I'd also note that my subs are also on stands with rollers. I'm wondering how much the bass curves are being affected by the rollers? I'd expect the rollers to have even MORE effect on the subwoofers than they did on the T2s because of the lower frequencies. Is the measured dip from my subs not from the room or even from the subs themselves, but rather from a resonance frequency where the sub drivers are pushing the rollers around? So to summarize - my speaker rollers were detrimental to the sound and I didn't even know it until I removed the rollers. YMMV Boom Did you run an REW freq sweep? Excellent idea to separate the subjective from the objective. And easy enough to do, too!
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Post by foggy1956 on Jul 5, 2020 10:24:59 GMT -5
Did you run an REW freq sweep? Excellent idea to separate the subjective from the objective. And easy enough to do, too! Agreed, a 10hz swing should definitely be visible. As often as Boom hears a quantifiable change in his sound, REW should be mandatory.đ
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Post by boomzilla on Jul 5, 2020 11:48:15 GMT -5
Did you run an REW freq sweep? Excellent idea to separate the subjective from the objective. And easy enough to do, too! To do that, I'd have needed to run one while the speakers were still on casters, and then another once they were on outriggers. Since I didn't do the former, I'm not going to take the time to reinstall the casters and do it now.
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Post by monkumonku on Jul 5, 2020 12:20:33 GMT -5
Excellent idea to separate the subjective from the objective. And easy enough to do, too! To do that, I'd have needed to run one while the speakers were still on casters, and then another once they were on outriggers. Since I didn't do the former, I'm not going to take the time to reinstall the casters and do it now. Ok, that makes sense. Lot of hassle to put those casters back on.
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Post by foggy1956 on Jul 5, 2020 12:45:24 GMT -5
Excellent idea to separate the subjective from the objective. And easy enough to do, too! To do that, I'd have needed to run one while the speakers were still on casters, and then another once they were on outriggers. Since I didn't do the former, I'm not going to take the time to reinstall the casters and do it now. Maybe run a sweep to compare for the next time?
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Post by boomzilla on Jul 5, 2020 13:16:31 GMT -5
To do that, I'd have needed to run one while the speakers were still on casters, and then another once they were on outriggers. Since I didn't do the former, I'm not going to take the time to reinstall the casters and do it now. Maybe run a sweep to compare for the next time? Will do.
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Post by foggy1956 on Jul 5, 2020 13:33:05 GMT -5
Maybe run a sweep to compare for the next time? Will do. Please post the results?
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Post by boomzilla on Jul 5, 2020 13:36:32 GMT -5
You got it!
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klinemj
Emo VIPs
Honorary Emofest Scribe
Posts: 14,742
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Post by klinemj on Jul 5, 2020 15:23:56 GMT -5
Your layout options make me think of my college days. We had limited layout options in our dorms and apartments, and one time I was staying in the dorm over a break and most people were gone. There was a room sometimes used for special dinners, and it was really wide and really long. The dorm let me and my friends take it over a few days, and we set up various variations of our stereos in different layouts to try it out. One time we ordered pizza and they asked for our room number. We just told them to come into the dorm, southeast wing, floor #2, and walk toward the music. They found us!
I am very blessed to have a dedicated listening room that's pretty good sonically...best I ever had. I still would love to design a room from scratch for 2 channel!
Re. the T2 sound change...glad you did the change. I have always heard that more direct coupling of speakers to the ground is best for sound, so I always have practiced that. I don't know it really makes a difference, but it makes me feel better.
If you were to ever try the double-stacked T2's...the interface between the upper and lower pair and keeping them stable would be a primary concern of mine.
Mark
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Post by boomzilla on Jul 5, 2020 18:14:50 GMT -5
...If you were to ever try the double-stacked T2's...the interface between the upper and lower pair and keeping them stable would be a primary concern of mine. Mark Got it covered. Industrial-strength self-adhesive Velcro (available most anywhere) is sufficient. How sufficient? Once Velcroed together I bet I can lift the "bottom" speaker completely into the air by grabbing the top one and lifting. The interface is THAT strong. And it's the nature of Velcro for vibration to make the felt-to-hook bond even STRONGER! So as the speakers play, they'll be stuck together even more firmly! I've used the stuff on every stand-mounted speaker I've had since I discovered the Velcro, and have never ever worried about knocking a speaker off a stand. It's that good.
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klinemj
Emo VIPs
Honorary Emofest Scribe
Posts: 14,742
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Post by klinemj on Jul 5, 2020 20:06:53 GMT -5
...If you were to ever try the double-stacked T2's...the interface between the upper and lower pair and keeping them stable would be a primary concern of mine. Mark Got it covered. Industrial-strength self-adhesive Velcro (available most anywhere) is sufficient. How sufficient? Once Velcroed together I bet I can lift the "bottom" speaker completely into the air by grabbing the top one and lifting. The interface is THAT strong. And it's the nature of Velcro for vibration to make the felt-to-hook bond even STRONGER! So as the speakers play, they'll be stuck together even more firmly! I've used the stuff on every stand-mounted speaker I've had since I discovered the Velcro, and have never ever worried about knocking a speaker off a stand. It's that good. I'm sure it will hold and prevent macro-movement, but...I'd still be worried about micro-movement. Any hook and loop materials (of which "Velcro" is a common name), there is inherent micro-movement. Of my 130+ patents, many are related to variations of hook/loop fasteners and their application, so...I've studied them "more than the average bear". Micro-movement = transmission of vibration. If it were me...I'd put a thin, compressible sheet of something rubber-like between the stacked speakers for vibration elimination and do something like come-alongs to strap them together. Micro-movement is the same reason I would not use the casters/rollers you have had on the T2's. Mark
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Post by boomzilla on Jul 5, 2020 20:10:25 GMT -5
But isnât the rubber sheet for âvibration eliminationâ allowing âmicro-movementsâ too?
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