I've been super happy with the Stack EQs over the Isoacoustic Oreas under my AGD Gran Vivaces, BHK preamp, Innuos PhoenixNET switch and ZENith Mk3 server/streamer. I also replaced Herbies Giant Titanium Gliders under my Fyne F703s with the AUVA 70s. Amazing improvements in bass definition and extension, dynamics, soundstage depth and width and a vanishingly low noise floor without any hint of darkness...
Stack Audio Products Review
After reading a number of rave reviews of the Stack Audio products I decided to try them and see if they could improve my system. Stack offers a 30 day money back guaranty and they even cover return shipping which is made very easy as they will email you a return Fedex Label.
They have several products:
A Turntable Vibration Mat
A Record Stabilizer Clamp
A SmoothLAN Ethernet Filter
Component Isolators
Speaker Isolators
I don’t have a turntable so I did not order the first two items. Their unique patented isolation products absorb and isolate components and speakers by decoupling them from whatever they sit on and absorb any vibrations. The reviews for these products while not numerous have all been exceptionally positive so I was very much anticipating trying them in my system.
The first to arrive was the SmoothLan. This small rectangular box sits between your Internet access and your streamer. In my system I have a Wifi Extender connected to my EtherRegen Switch which is then connected to my Aurender N20 via a DH Labs Reunion EtherNet cable. I connected the SmoothLan between the switch and the Aurender. The SmoothLan includes a short quality EtherNet cable to use as a connector. Some have connected the SmoothLan before the switch but in general most do as I did. Some even have a SmoothLan on both sides of the switch.
My initial reaction was that the SmoothLan did in fact smooth the signal. It seemed to smooth the high end but in my system at the expense of high frequency extension and openness. It seems to take some of the atmosphere and air away. So I removed it for a while. After a day or so I tried it again with the same results. I think that it was most likely adding additional filtering that I don’t need. The EtherRegen, the Reunion Cable and the Aurender all do an excellent job of cleaning up the Ethernet signal. So this product will likely be of benefit to those who do not have a quality switch, cable or streamer that are already cleaning up the signal. I contacted Stack and arranged for a return. They emailed me a label and I dropped it off at the local Fedex. BTW this product is about around $250.
The next to arrive was a set of four Component Isolators. These approximately 2“ diameter by 1” high disks were more of a challenge to audition. I first placed them under the Aurender N20. I decided to placed them between the front and back Aurender feet on the sides. Some reviews said placement wasn’t critical while others said toward the sides or front as best. Anyway in this position the sound was disappointing. The highs were suppressed but they were also refined. I really don’t like anything that suppresses extension even if other parts of the response improve. I removed the Isolators from the Aurender and placed them under my MSB Discrete DAC. Here the sound was slightly better but still not to my liking. I next moved them to one of my DAC power supplies and found no difference than having them under the DAC. Finally I placed them under my Accuphase P4600 Amplifier. This gave me the best response so far. The highs were still not as open as I preferred but they were very refined and smooth and the bass improved. I kept them there until the next product arrived.
Next up were the AUVA Speaker Isolators. I received two sets of four of there Model 50. They have 70’s and 100’s which offer more isolation at additional expense. I ordered them with felt pads as I don’t like spikes and I planned to put them directly under my Harbeth C7ES-XD speakers which sit on Wharfdale Linton Stands. In this location with the Component Isolators still under the Amp strangely I found the overall sound to be somewhat brighter than I like. Bass was very good. Midrange was clear but the high end especially on strings was too bright. I then moved the Speaker Isolators from under the speakers to the bottom of the stand. I replaced the Linton stand’s feet with the Speaker Isolators using the bolts I had ordered that specifically fit the Linton stands. Stack offers a variety of screw bolts. You just have to tell them what speaker or stand you have. I had not ordered the spikes so the stands and Isolators were sitting on the carpet. In this configuration the sound was less bright but still not to my liking. After listening for quite a while and missing that smoother high end extension I moved the Component Isolators from under the Amp to back under the Aurender to see how they would sound there now that I also had the Speaker Isolators. This time I placed the Component Isolators under the very corners of the Aurender. The Aurender feet are recessed about two inched so it was easy to place them on the corners. This gave me the best response so far. After another day I was still sensing that I was not getting that openness I craved so to make sure I was not imagining everything I removed the Speaker Isolators and the Component Isolators and yes there it was that openness and upper frequency extension returned. But funny thing is after listening for several hours I realized two things. I missed the upper end refinement the Isolators provided and the deeper bass they offered. Also I started to notice that even though I had more openness without the Isolators it was at the expense of refinement. Totally frustrated I was at a loss as to what to do. Then I remembered that I had never tried the Component Isolators thought maybe the Speaker Isolators under the stands without spikes may be compromising their performance. So after making this change the magic finally arrived.
The bass was solid, the midrange clear, warm and lifelike and the highs were both extended with air and openness but also refined. In addition the images seemed to be more defined in the soundstage and when I increase volume I can hear a slightly wider stereo image. Also because the sound is cleaner and more defined I can play tracks at about 1 or 2 db loader than normal without any problem. Phew! What a relief. Finally a configuration that worked. So I will be keeping both the Component and Speaker Isolators.
I had also ordered an alternate isolation product to try: The Soundeck Mini MKII. These are flat circular thin metal disk absorbers. I ordered 8. So now I slid four under the feet of my MSB DAC. The effect was subtle but it slightly tightened and deepened the bass. At $13 per disk they are an economical way to quickly improve the sound. I tried putting the other set under my Amp and it was too much of a good thing. Similar to when I put the Component Isolators under the Amp it just dampened the upper frequencies. The Accuphase Amp has fairly large feet that are about 2” in diameter and almost an inch high with large rubber type inserts so it may already be handling vibrations effectively and dose not need any more dampening. So I removed them.
BTW the Component Isolators are under $300 for a set of four and the Speaker Isolators are around $500 for a set of eight. The Component Isolators come in three weight support sizes each priced the same. The Speaker Isolators come in three models: Good, Better, Best. Each with increasing isolation and control as the price increases. I ordered the Good one: Model AUVA 50.
Hope this is helpful to those interested in vibration control and component decoupling. There are a lot of products and some very expensive but either the Stack or Soundeck offer a very reasonable alternative that works if you have the patience to experiment. I’m retired so I could spend hours each day trying different configurations and listening to my list of reference tracks over and over. You may not have that luxury.
One final note. While I was going through this time consuming audition I thought about those reviews where the reviewer instantly found impressive improvements when using these products and wondered why didn’t I. I think it has to do with two things:
First my system is very neutral with a slight emphasis on warmth. Second my room is also warm with carpeting, plush furniture and little to no reflective surfaces. If you have a live room or a system that is bright or both I could see how the taming and refinement of the higher frequencies could be immediately appreciated.
Let me know if you have any questions about these products I haven’t covered.
25 responses Add your response
My take on AUVA 50 Isolators - I have been listening for last few hours in complete amazement. They have unleashed new level of more focused and detailed sound. The improvements are across the entire range…mid-range is more palpable and bass has further tightened up on my 15” woofer. These improvements are over well respected Eden Sound brass footers, which were huge improvements over stock footers. The AUVA goes further, much further over Eden Sound. For the money, 2 sets of 3 footers -$350; underneath my Tannoy Canterbury’s proving to be one hell of a bargain. Can you do better, I am sure you can but count on being spending atleast 2-4 times. Pics of AUVA 50 uploaded in my virtual system. Next up, component isolation; stay tuned! |
I agree with your assessment of the sound presentation of the Stack AUVAs. However I found that only to be true when the AUVAs were placed under my speaker stand with the larger 25mm spikes. When I place the AUVAs directly under my Harbeth speakers on the stand the sound perspective is open, airy and with a soundstage of greater depth. I just did this comparison yesterday. Under the stands gave a more refined but slightly rolled off high end and more energy in the lower midrange, It's a very euphonic sound but to me lacked that liveliness I prefer with extended highs and that's what I get with the AUVAs directly under the speakers. I also have a set of the Stack Component Isolators and found the best response achieved for me is placing them under the very corners of my Aurender N20. Placing anywhere else under the Aurender rolled off the highs. I sound placing them under my MSB DAC or either of its power supplies also rolled off the highs. Both the Aurender and the MSB I believe already have vibration control feet so adding additional control may be too much. Only my theory. They also did not work under my Accuphase P4600 Amp which already has very larger cast iron feet with some kind of absorption material. |
The AUVA products like the EQ have a particle damping system. This I presume results in peaks and brightness tamed - at the expense of transient performance. I found the AUVA EQ to have a warm spaciousness, with increased soundstage depth, moved a bit away from the listening position. But clarity and air was slightly reduced compared to my 6x more expensive Stillpoints Ultra SS. So the AUVA EQ is a fantastic product for the money, but I still prefer the sound of Stillpoints. As well as listening preference I think all isolation footers work better in certain systems, heavily depending on the gear you have. |
@baylinor Thank you, I just hooked it up and will play around with positioning etc. after a good run in. Nothing negative to report so far as an initial impression. Cheers gents. |
They recommend placing it right before the streamer. That's where I started, then just before the optical isolation and finally right after the wifi extender and I went back and forth multiple times. In the end, I couldn't tell any difference, they all suffered from the same contraction of space, air and clarity. I hope it works for you. |
@baylinor my Stack SmoothLan arrives today and we will begin my placement experiment this week. Only have a few days to play with it before a trip to Michigan. Nice thing is their generous return policy. I too have fiber to the house and fiber optimization in my system. Will try it on the dirty side in my Modem / Switch room on the west side of my house. Have an EE1 on that side now and it is effective. . |
I got the same exact experience with the SmoothLan. My Triode Labs Freedom ethernet cable goes first into an optical isolation bundle (with LPS) then into a LHY SW-10 switch which is connected to the Innuos ZENith mk3 streamer via a 16" Freedom ethernet cable. No matter where I inserted the SmoothLan in that setup, it restricted the sense of space, air and clarity. I told the guys about it at Stack Audio when they asked me for my opinion of the SmoothLan and I never heard back from them. It makes me believe they may know the limits of their filter in well built ethernet feeds. |
I have the Component Isolators under the Aurender positioned at the corners and the Speaker Isolators directly under the speakers on the stand instead of replacing stands feet on the bottom of the stands. Then I placed four of the Soundeck Mini MII Disks under the feet of my MSB DAC. That's the final configuration. Listening this afternoon and the sound is the best I've been able to get out of this system. Also noticing more that the soundstage is larger in depth and width and really impressed with the low end. The low end especially on Classical recordings is really solid and impactful. It sounds like I have a Sub. Actually I had two REL Subs but sold them because the Harbeths had a decent low end down to the high 30hz range and I found the Subs difficult to integrate with the Harbeths.The Subs keeps coloring the lower midrange and messing up the soundstage. Now the bass is really impressive. Nice changes for the money. |
Nice detailed review but quite honestly I can't follow the last change you made that made things sound good. What was the configuration exactly? |
These weren’t negative reviews . The products do what they claim. It’s just in my system one of them didn’t match. The other two Isolator products certainly work. I’m enjoying a very improved system. However it took some effort to find the right location and mix. And as I mentioned my system and room may have contributed to the difficulty getting the right positioning. I might add that their benefit is more valuable under digital components than amps in my system. Yes the Spikes probably would have worked as well. However I’m happy with the results under my speakers on the heavy Linton stands. My Harbeth’s weight is about 29 pounds. |
jfrmusic, We all have different systems and experiences, especially when it comes to sundry products, like footers/isolation devices. The only thing I would like to comment on is, speakers on stands may be a large variable. I am not sure of the weight of your speakers, but I am using the Auva 100 with the floor spikes. The use of these may change your opinion. But it is good that there is an easy return policy, sometimes you just never know until you try them. ozzy |