Tony,
I’m driving the GTI up with a case of BIG-K diet soda and mixed nuts! I already mounted the TOLL pass RFID tag on that clear stick-em so I can remove it for next year and on and on. I also checked and put 40 PSI in the tires and 60 PSI into the mini spare. I check that one every spring.
Galen
Didn’t realize you were driving! Safe trip!
Many asked about another presentation at AXPONA 2027. OK, you talked me into it. I was kind of shocked, in a good way, so many have seen the VIDEO section of the ICONOCLAST web site.
I am going to work up a presentation on the development of the IC cables, and how the ICONOCLAST isn’t a one trick pony design. SEVERAL things had to all be aligned to get what I wanted out of them for me, and you, to hear. I didn’t just address Vp alignment between the balanced and unbalanced cables. I’ll go through all that and if it worked, and how to even tell if it really worked (measurement).
This isn’t new, of course, but it isn’t really compartmentalized for easier mental digestion. I’ll do that and, also of course, many have no idea all this information exists so I’ll make it into a presentation format for AXPONA next year. Kurt has already supported the topic and idea for something fun, interesting and factual.
All the gory stuff will be explained so everyone can see what the design is doing, how it does it, and why. Also, this topic can apply to ANY balanced to unbalanced if a designer is even aware of how to do it. So until next year!
Galen
Wait. You mean waving hands, using made up buzzwords, and claiming having sourced a rare supply of military / aerospace 12 9s copper infused with an unobtanium version of graphene isn’t the way to show you know what you’re talking about? 
A note of thank you to our MANY friends and customers who stopped to visit and speak with Kurt and Galen at Axpona. I hear that it was extremely busy. As always, Treehaus Audiolabs used a full loom Iconoclast set up on the very impressive system upstairs. Thank you Rich!
Rumor has it that the foretold price increase could take place as early as next week.
This would be a great time to fill any gaps or needs for cable assemblies!
Great sounding room, with great speakers and a cool looking equipment rack!
I have my sources and preamp wall mounted on the side and two pairs of amps between my speakers. My speakers are split with a planar magnetic tweeter and midrange on top and a dual servo controlled subwoofer section below. One amp for the top and one for the bottom. From the preamp I ran a 15’ pair of BAV RCA interconnects to my upper amps where I had RCA splitters and a short BAV RCA cable to each sub amp.
With this arrangement I got very good sound but also a small amount of transformer hum which I could never quite get rid of. AC filter, DC filter, didn’t matter. Fortunately it was low enough that when the music was playing I could hardly hear it. Not perfect and only somewhat annoying due to the prices involved but I still had options to sort it out.
A few weeks ago I jumped on a 15’ pair of 4x4 XLR interconnects before the price increase. I put them between my preamp and the upper amps. I took out the rca splitters and short cables to the sub amps and plugged the long RCAs directly into the sub amps.
Fired everything up and…
Nothing. No hum. No noise. Everything was dead quiet. I played some music with acoustic guitar and it sprung forth from the nothing sounding both relaxed and vibrant simultaneously. Last night I listened for two hours and had to pry myself away to go to bed! A pricey upgrade but they took my system to the next level!
With the splitters in the RCA, you likely created a ground loop between the two sides not being perfectly equal, and the hum. The issue is going to be random depending on all the grounds potential to true ground. The BAV or ICONOCLAST will both give the same result as both use the same ground DCR shield. One will just have a finer voltage signal, but not a better ground differential. Don’t try to buy up to get out of this problem, you can’t unless the shield DCR is LOWER!!
Running an RCA to each side separate, the ground differential isn’t as bad thus no hum. An RCA is limited by the outer shield DCR to mitigate the end to end DCR differential that single ended will ALWAYS have, and why we use two super heavy braids to keep longer lengths noise floor as low as practical (30 feet or so). We have a wire between the ends that has to have DCR, so we creat a bigger and bigger current loop the farther we go. It is that simple. Don’t go for any answer other than the right one.
What RCA remove is CUB imbalance. We have ONE voltage to a signal ground reference and XLR are nor perfectly balanced from plus to minus sides and have capacitance unbalance, CUB. But, in a longer run that 1%-3% CUB is way better than HUM. Short RCA’s have the most accurate voltage transfer since no CUB imbalance is there and the DCR imbalance can be low in proper length runs so we don’t have noise above -100 dB or better. Many fine and super high level amps are unbalanced for that reason.
An XLR doesn’t use a “ground” as a reference but a floating virtual ground between PIN 2 and 3. PIN 1 is a true RF shield with BOTH ends GROUNDED at each end!! The signal doesn’t use or see PIN 1. XLR distances are more attenuation and driver limited assuming the driver circuit is balanced properly. Not all are. An XLR circuit is more complex and expensive to get right. Both the cable and the driver/receiver have to be “identical” to keep the differential voltage levels what they are meant to be.
Each cable used right is the answer, and you found it!
Best, Galen
Here is my rooms response where I sit with some EQ. Notice the data above 42 Hz is point to point equal and opposite for R and L channels at each frequency tested. This presents a flat power envelope at the 85 dB reference line and about where my average listening level is. One channels peak just cancels the other’s null along the way. I’ll take that!
Below that we see that my room has a ~36 Hz suck-out. Lower than most rooms that have stuff around 50-60 Hz, but my room is 38 feet long, so a lower resonance issue. You can’t fight the room’s natural issues, so be careful with BOOST.
The six REL’s are getting it done in the 20-30 Hz region, but you can’t fill a hole. It is 6 dB to the 8 dB reference, but it is there. My P3100HV has a three band paremtric EQ, and the lowest band I set to 35 Hz and +3.0 dB to address the null. I don’t want to push it too hard that low. Every 3 dB is twice the power. There was a hump at ~60 Hz that I tapped down 3 dB, also. Peaks are easier to tame.
I used Vandertones 20 Hz-120 Hz off the website and a calibrated (how well?) SPL meter placed where my head would be. My seat is in the 0.84 ratio spot, 100 inches between speaker tweeter panels and 84 inches from my head to the tweeter panel. And yes, I do have a null there as well. Do I get worse imaging to fill that hole by moving the chair? A question you have to ask yourself. And, it will be in another null/peak region. I’d rather have a null way low than a peak up higher. Less intrusive to clarity. My answer was no. Listening tests were very good with the 36 Hz null. I kept the 0.84 ration seated position.
Notice that the balance is 1.5 dB to the left (each step is 0.5 dB or 3). This centers the power distribution eveny around the 85 dB SPL level to center the image. The right speaker is near a wall, the left out in the open and the data shows exactly what happens with them sitting in the L-shaped room. I had to fix that too.
I might be able to tweak the TOP sub @ 35 Hz to fill the 36 Hz hole some, but I need to be sure it doesn’t over emphasize the 20-30 Hz region that’s pretty good. The top sub being up high, has way less impact down low, no reinforcement. It might work if used gingerly. One other point, if you crank a setting +6 dB and a hole remains the same, BACK OFF that setting! It’s just not going to happen at that spot in the room and stresses the dickens out of the driver. Go back to a setting that is more tame, maybe +3dB or so. I had to do exactly that. We seem to worry about peaks and all sorts of absorbers, but we have frequency holes that are just as problamatic and get little mention. When it comes to nulls, the room wins.
The EQ did make me realize I was way off from flat down low 20 Hz-30 Hz, and had to move the subs cross-over frequencies UP to 30 Hz, 35Hz and 35 Hz bottom to top, and increase the levels almost twice where I was before. Now I’m flat and am using all six REL’s as they are meant to be used. Nice and even down low.
You learn your ears can play tricks on you along the way. I decided to go with the data, those that know won’t be surprised at that. The new settings are far better than where I was before. Maybe still not perfect, but where I’m seated pretty good.
We all approach this a little diffeently and I went with the data to see what would happen and it’s a far better set-up than my guessing ears provided.
Best, Galen
Nicely done Galen.
My understanding is our ears are much less sensitive to nulls than peaks. I question that because it’s difficult to know what’s missing until it’s been replaced but I also haven’t been curious enough to experiment.
Bad storms near here. It seemed nice out but the power went cablowie and cycled almost six times; bam, bam, bam, bam, bam, bam. YIKES. I ran downstairs and the P20 worked as it should, all was shut off and I have the P20 is set to re energize each stage every 15 seconds after a 45 second full “off” to shield the stuff from the wall. After a couple of minutes, all was well again. I listened to music all evening. That P20 has been a great purchase if just for that alone. It is the most unloved but faithful unit in the stereo. It needs a pat on the head now and again.
Well deserved. I can’t say I’ve ever patted any of my audio gear but the bike gets the occasional love tap, sometimes for doing nothing more than just being there as I walk by.
