Thiel Owners

Some important news was found out from my DRC measurement steps (first step actually).

I want to clarify a point about the slight harshness I was hearing on the CS3.7 top end. I was saying it was not as smooth as the KEF LS50.

The measurements showed that right speakers Coax driver is out of phase with the left speaker Coax (maybe one can say the opposite). There is some harshness on the frequency response due to this miss-wiring. I guess my hearing is good.

Prior to the sale I knew that the previous owner got a new Coax driver from Rob G and soldered the Coax wiring himself. He was a little worried about the wiring since there was a 2 week delay with shipping the driver to Rob and getting the new one. Anyways, the previous owner and I are working to get this fixed, should be an easy job. I will give Rob a call tomorrow to find out the specifics of the job.

So the DRC work is halted until this out of phase issue is resolved. I am going to find some electronics guy/gal to do the solder, since I am a newbie on that and I want it perfect.

BTW - the engineer up in Canada, Mitch Barnett, used to owned Thiel CS3.7 and he loved them.

@jafant My pressing of the SACD is from SME records. I now have my SACD player less than a foot from my seating position. Makes things easy. Getting real lazy with age.

I called Rob Gillum about the COAX installation know what needs to be done to resolve the out-of-phase issue. I have decided to use the services of a local audio store in Santa Barbara. They will send a repair tech to my home next Tuesday to do the soldering. Learning a lot of technical stuff with this hiccup.

I decided to move the Thiel CS3.7 to a new position. I now have them 2 feet from the front wall and about 2 feet from the side wall. The speakers are now closer together about 6 feet apart. The sound now is better than any other prior placement. Even with DRC I will keep this positioning, mainly because I have 3 out of 4 sources that will not use DRC. Only my digital streaming via ROON will use DRC (if I like it).

So next week is when the interesting stuff happens. Enjoying the out-of-phase tunes until then.

I also bought an CS3.7 Outrigger for the speaker feet. My 4 year old first words when he saw the CS3.7 in my office was "I want to climb it".

I cannot play with the placement other than these minor movements. I bought the CS3.7 on the assumption that if it did not work in the office. I could eventually move them downstairs to the much larger living room. The living room is my sons play room at the moment.

However, the placement that I just did is great. Given the circumstances of this room I am extremely happy about the sound, except for that harshness. which will be resolved on Tuesday.

I will say to prospective CS3.7 buyers that the speaker will play in a acoustically treated room small room, see my Virtual System on A'gon. I understand that I am not getting the very best sound out of the CS3.7 but, what I am getting is very good. 

Reading everything on the web on this room size issue made me think it would not work. I am shocked actually that this is working so well and I am not getting overwhelmed with bass. I still have the DRC implementation that I can bring to the table to potentially make things even better.

Thanks everyone for the great info provided here. It has made this problem pretty easy and fast to resolve. I have a speaker repair tech from the local high end audio store coming to my home next Tuesday. The cost is not much for 1 hour work and the speaker seller has volunteered to cover the expense. The estimated cost is pretty low (so far) so not concerned. I will have everything ready to just unsolder and re-solder.

The speaker tech is aware of the battery test though the sound engineer in Canada told me to send him another set of measurements and he will tell me if it is setup correctly. I will see how experienced the repair guy is before I figure out which way to test it.

I received the following feedback from Rob Gillium today about the wiring.

The CS3.7 is a three way speaker, with a Passive Radiator. Each crossover section has a pair of output wires. There are three pairs. One pair to the woofer, one pair to the midrange (coax), and one pair to the tweeter (coax). The coaxial driver is a two driver combination, (midrange and tweeter). Each driver has a pair of wires. The white output wire is positive and should be connected to the red terminal of each driver. The black wire is connected to each unmarked. terminal of the drivers. These wires must be connected in this fashion, to be in phase with each other. If one of the drivers are connected out of phase (reverse polarity), then it will cancel the output from the other driver, thus rendering poor sonic quality. It is very important to connect the midrange pair to the midrange, and the tweeter pair to the tweeter. If these are connected wrong, then the tweeter will see the mid frequencies, and be destroyed in most cases.

I was also speaking with a CS3.7 owner in Brazil who is active on the ASR forum and he thought the Coda #8 V1 would be what he would select from the #8 options. However, he did mention that Purifi is going to come out with a new module that will have similar specs as the NC1200. He is waiting on that before any new amp purchase. He suggested I do the same.

I have a feeling the current Purifi module sounds very similar o the AHB2. A future module with the the same sound but NC1200 power specs would be great for the CS3.7.

I should say again how happy I am that I payed attention to TomThiel’s post about positioning. I was initially trying to get max space between the speakers with low side and later low front wall spacing. Now with the speakers around 2 feet from the front wall, 2 feet from the side, and only 6 feet in-between, the sound is really good, the best so far.

From a placement standpoint the coax is magic.

I agree. I have had a few speakers with the tweeter and mid on the same driver unit and it has always made placement much easier. I am slightly off center in my seating. With my KEF LS50's (also a similar type of driver) I had to make an adjustment on my preamp's balance to give the far speaker a bit more juice. With the CS3.7 I set the balance to 0 and it sounds great. The sweet spot is bigger than most speakers. The KEF Blade is also like that with a big sweet spot.

Sounds like you are a music fan. When my kid was under 2 years my office/audio room was in a laundry room. I would work and listen while a washer and or dryer was going full blast next to me usually washing kids stuff. Still enjoyed music.

@jafant I ordered the Mofi version of Santana’s Caravanserai. My current SME version now sounds better on the CS3.7 than on my Meze Empy headphones. It sounded better on the headphones prior to my speaker repair today.

Looking forward to the MoFi version since you say it is the better version.

I want update my journey with the Thiel CS3.7 now that some changes were made.

1) A speaker repair tech came to my house today and re-soldered the crossover wires to the tweeter and midrange of my right speaker. They were wired out-of-phase during a prior DIY OEM COAX replacement. The speaker seller has volunteered to pay for todays repair.

2) I discovered a damaged screw thread on the left speaker frame. Rob Gillum pointed me to a toolkit to repair that. It is being shipped to me now ($44). The original speaker dealer seems to have gone torque crazy with the driver screws.

3) I will sandpaper and lacquer the speaker because this speaker is never leaving. Rob Gillum gave me instructions on best approaches for that.

4) I ordered the outriggers from Rob G. for the day that my 4 year old son decides to climb the speaker.

After #1 was done today the speaker sound just opened up. The harshness is gone and the soundstage is huge the imaging is better. Just like I remembered 12 years ago at the store demo. I think it actually sounds better today on my all Benchmark stack than the all Classe gear of the demo.

Getting to that Benchmark stack. I have been disparaging the AHB2 Stereo amp with the CS3.7. Saying it sounds lean and not dynamic. I was thinking in my small room 194 watts at 4 Ohms should have worked. The amp also goes down to 2 Ohms but I do not remember the numbers for that. However, the sound was not that good wherever I positioned the speakers. I think I said on a scale of 100 it felt like a 75, even less on dynamic music. Today, after the out-of-phase fix the sound is powerful, dynamic and glorious. I would say a 95 out of 100 now. The room is still there so not a 100.

I am kind of curious still about the CODA #8 amp with the CS3.7 but I do know that the AHB2 will never leave this system. I caught a lucky break by not selling it a few days ago to fund the purchase of the #8.

So in a small room, see my Virtual Systems, the Thiel CS3.7 + an all Benchmark stack (with a single AHB stereo amp) sounds amazing.

I will explore the DRC implementation tomorrow now that the drivers are working right.

BTW - I was just thinking that reason that the it was easy for me to hear the out-of-phase problem was because of the revealing nature of the Benchmark gear.

I also now feel that for my room the Luxman m900u and the CODA #16 would also be viable alternative amps. I do not need the massive amounts of power at 2 Ohms for this room.

@unsound Yes, I am paraphrasing his comments in my email with Benchmark. I am just crossing my T's and dotting my I's before I close the door on the mono AHB2.

I have been looking around the net for alternative amps, if 2 x AHB2 is a non-starter, I keep coming back to the CODA #8.

I am trying to figure out why people have recommended me to get more Class A first watts instead of more Class AB watts at 2 Ohms with regards to the CODA #8. I guess I can always circle back and discuss again with these folks.

Thanks for the feedback. I am not sure what musicality means but I do know that gear like the Luxman m900u have a softer presentation of the sound. Likely like the Gryphon but with the Gryphon having more slam. The USA distributer of Gryphon is local to me. I am sure I will hear their gear next time there is a big show in my area.

I am participating in a HPA4 preamp/headphone amp thread on another forum and someone there is saying the same thing about the HPA4 which sounds exactly like the AHB2. Too neutral no magic, etc... It is just a matter of taste. 

Now I loved the sound of the Luxman m900u. I also love the totally different sound of the AHB2. Both are amazing at what they do. The CODA #8 or #16 is described as being similar to the Luxman but with more slam. The CODA is a ton cheaper in the USA with a 10 year warranty. So that is why I have mentioned the CODA so often. I can also get it customized with some SpeakON speaker connector to make my amp switching task with an AHB2 a breeze. 

The AHB2 will always be part of my collection. It is a brilliant amp. Some may not appreciate its naked sound but I love it. It sounded the very best today after the out of phase fix I mentioned previously. I wonder if I would have even noticed that problem with another amp?

Great feedback. Some updates.

1) Rory at Benchmark forwarded my email to John Siau, the amp designer. He has the Thiel CS3.7 specs from Stereophile measurements linked in the email. He is out now but I hope to hear from him once he gets back.

2) I am trying to get my speaker measured again today to send to the Audio Engineer in Canada for the DRC. A lot of crazy stuff happening in the home front (like flooding, no babysitter, etc..) so I need to sneak in some time.

I will work with a dealer if I get the CODA as an alternative second amp. This dealer also has Krell. He said the new Krell XD is somewhat like the CODA but even warmer. Though for the cost differential it is a no brainer to get the CODA. As I mentioned before the power specs on the specific model I am referencing #8 is perfect for the CS3.7. There are 3 versions to choose from. This is set at the factory.

• 150 watt @ 8 Ohm (first 18 in Class A) | 300 @ 4  | 600 @ 2
• 250 watt @ 8 Ohm (first 12 in Class A) | 500 @ 4 | 1000 @ 2
  
• 350 watt @ 8 Ohm (first 8 in Class A) | 700 @ 4 | 1400 @ 2
  

The cost is under $6K with 10 year warranty. Another great American company like Benchmark and Thiel. CODA can also customize the speaker outputs for me, to use SpeakON so that flipping my SpeakON ended speaker cables would be a breeze. I would never need to unplug from the speaker end.

@tmsrdg Thanks for the follow-up. I thought of your earlier posts on the AHB2 with the CS3.7 and did decided not sell to fund a new CODA #8 because how much you liked it. I figured something was not right on my side and wanted to wait until at least the DRC work. Now it is really a great sound even without DRC. It is shocking actually the difference since the wring was fixed. I now know I have 1 of the 2 best speakers I have ever heard.

@thieliste
There is the meat to the sound of the all Benchmark stack. It is not the warmish meaty+ Luxman sound but a great sound nevertheless. Not saying one is better than the other. I love both.

I have been in the demo rooms of many show with Philip Hanlon of Luxman and now Gryphon fame. I do not think I need to spend at his cost of gear to get the best out of the CS3.7 but until I demo the Gryphon this is an assumption. I must say that I am not a fan of "fat on the meat" sound, just "lean meat on the bone" is fine. Luxman was one of the few that I liked that was tubey and warm sounding, but I did not want to cross that limit of meaty sound. Different strokes for different folks.

BTW - In December The Absolute Sound will do a review of the gear I have, maybe minus the AHB2. Which will be good for me to read how other amps work with my stack. 

@thieliste I appreciate your feedback. I will give it a try since it is so easy for me being local. I do not want an integrated since my system positioning is setup for separates. I wanted a cleared path from my speakers to my ears. I am very happy with what I have done to facilitate this in a small room. I will check out their dedicated amps instead.

I just did some quick looking at the Gryphon amps and they seem like competitors to the USA made CODA #16.

I am currently listening to Santana’s - The Woodstock Experience and while it sounds very good and I am bopping along. I would like more power to really feel that percussion.

@unsound you are correct about the 25% reduction at 2 Ohms. I asked them since you mentioned it before. I am not a big Class A guy. Whatever gets me to great sound will work, Class A, AB, D, etc..

This journey I am talking with the CS3.7 is hitting rough patch after rough patch. It is not really bugging me though, a little interesting actually. Learning a ton of stuff about audio. My background is as an expert listener of music. :)

Today I did the REW software measurements of the 2 speakers. The new issue is that the Sound Pressure Level graph of my LEFT and RIGHT speaker are not identical. There is sufficient divergence between the L and R to indicate that something is wrong. This divergence occurs at 1K level. I got this feedback from the Audio Engineer who analyzed the data.

So I am going to learn how to interpret the REW software correctly and measure my KEF LS50s myself to eliminate the very new Benchmark gear as the culprit. I am almost 100% certain this less than 6 month old brand new Benchmark gear is flawless.

I have an idea what the issue is but will not speculate here until I speak with Rob Gillum tomorrow morning. If my hypothesis is correct it will cost me some funds to fix it.

I should note that both COAX drivers are in phase now and to my ears the system sounds great. However, I cannot move forward with the DRC until the SPL graphs are almost identical.

BTW - I was just playing The Boy’s Doin’ It - Hugh Masekela. That sounds so good on the CS3.7

In a previous post, I described the 2008 COAX terminal connection backwards (not important).

I just got off 2 email threads. 

1) The Audio Engineer in Canada, Mitch Barnett, looked at the new graph I sent him and said we know for sure it is now the COAX drivers that have a problem. 

2) John Siau from Benchmark looked over the specs of the Thiel CS3.7 and said the amp will work in mono. That is the mono amp will not damage the speaker. I should take the 30 day home trial and see if it actually improves the sound.

3) I will get in touch with Rob and pick his mind on what could be the cause of the COAX issue.

The simple reason I like the Benchmark gear is because with this gear  I experience the illusion that I am in the studio or audience during the performance. I think it is their SNR that makes this magic happen for me. 

That is also the reason I like the KEF Blades so much. Those speakers bring the performance into my room better than anything I have ever heard. The Thiel CS3.7 are also pretty good in that regard too.

@unsound Thanks for the feedback.

I was thinking that could be the case. What I did first was put my KEF LS50's back into my room and measure exactly as before. This measurement setup was done with the goal of removing the room as much as possible. The microphone was placed 3 feet directly in front of each speaker and my LEFT and RIGHT test tones were run from ROON. One tone per speaker and the analysis was done on my Windows laptop running REW

With the CS3.7 the Sound Pressure Level (SPL) graph on the REW software shows a lower level on the replaced COAX driver at 1K to 20K.

On my KEF LS50's the same test results in an almost 100% perfect match in the graph lines for each speaker. Beautiful to see that.

So the issue is not with my gear or the testing process. It is now isolated with the 2 COAX's. 

The COAX that was originally wired out-of-phase was built in 2012 (there is a date sticker). The COAX on the other speaker also has a data sticker of 2008. It also has some electronic piece that is soldered onto the uncolored terminal (non-RED). A tiny label on the piece says something about 5% adjustment. I took some photos of this and got confirmation from the previous owner that Rob Gillum told him the 2012 COAX does not need this extra soldered piece.

I was not able to reach Rob today but I have a feeling I will have to get a second 2012 driver to make the SPL identical. As I said in my prior post, the sound is really good now. There is nothing I hear that tells me there is a problem. However, I am curious about going forward with DRC so I will replace the COAX if that will fix this issue. This has to be resolved before DRC can be done (at least with the Audio Engineer I am working with).

@unsound

Your comment ties in the what John Siau emailed me today.

When ss amps clip, it’s sudden and ugly. With ss amps t’s best to keep far distance from the clipping point.

John’s last comment in the conversation.

Yes, it will work well in your application. The feed-forward error correction keeps the amplifier distortion-free when driving low impedances.

Or maybe distortion and clipping are not the same thing? 

Regarding searching for new speakers. I am very happy with the CS3.7’s I am enjoying the heck out of them now. I am just trying to squeeze every bit of performance, especially in a challenging room. What I have now is great, let me try for excellent which the CS3.7 is capable of. I do want the 2 COAX’s to measure the same though. Need to fix that.

I am going to one day build out a living room system. That will be using different gear and the speakers will likely will be the KEF Blade or Yamaha NS5000. Along with the CS3.7 the other 2 are my fav speakers. A shame these things cost money.

@tomthiel When I get the AHB2 in mono would it be useful for me to use two 3 foot speaker cables instead of the two 6 foot cables?

In the case of my Revels the amps were very powerful, but I do understand your point about underpowered amps.

@tomthiel Thanks for that explanation.

@jafant  I am listening to the MoFi version of Santana's Caravanserai and I am amazed to how good it is. Maybe my second best SACD disc now after DSOTM.

There is no comparison with the SME version. The MoFi has bass that I can feel on my toes as I am stretch out listening. Not bass that bothers the ears but bass that should sound loud. The percussion is more powerful and you can feel it. You hear more of everything, and it is not a louder recording just a more vivid rendering.

Thanks for the heads up. I bought it on eBay.

This same AHB2 conversation was had in another A'gon thread in 2018 where John Siau participated. I don't think the folks responding to him realized he was the amp designer.

The vertical bi-amp will not work with the Thiel CS3.7 since it only has 1 set of speaker inputs.

As it stands:

1) The designer of the amp told me by email that the amp will be good with the speakers. He looked at the speaker specs.
2) The founder of the speaker company mentions that he has been testing 2 AHB2 for the last 2 years.
3) @unsound makes a great point about finding something else that does not shut down. I think there will another amp in the future to have in the stable.

At this point a second AHB2 is an easy buy for me. I love the sound of this amp. They are said to work with the 3.7's, issue is how well. One thing I have learned the last 2 weeks is that the CS3.7 is not a speaker to be played crazy loud. That is fine for my current application in my office. A little more grunt from the 2 amps will take me to an ideal spot.

@vair68robert  That is something to consider since I already have a speaker repair tech available to help me now. 

1) I have to fix the broken thread on the LEFT speaker frame for one of the screws. I have  repair kit being shipped for that. Hopefully I do not mess up that repair.

2) I have to fix the SPL divergence issue between the 2 COAX drivers. I hope it is not a crossover issue and a simple COAX driver replacement, to the 2012 spec'd COAX,  does the job.

3) I want to sand an lacquer the wood since it has some ugly sheen on certain angles. That was a prior DIY job not from the factory.

4) Setup the outriggers that arrived yesterday, though I will do that last.

5) Maybe add this bi-wire ability

Fun times and all I wanted to do was buy a speaker.

I was about to buy a second AHB2 last night on USAudiomart, but my PayPal was not setup the way I wanted. It will be tempting in 2 business days once my account is adjusted. Smarter move maybe be to pay a little more and do a home trial.

One thing that goes in my favor in buying a second AHB2 is that I have an orphaned KEF LS50 that needs some power. I was thinking the NAD M33 for that but I can happily get an AHB2 for that again.

Here is blurb from the AHB2 manual that I read last night. Which should be good for my small room situation where I won’t be blasting it full blast.

"Speaker impedance always varies with frequency. Speaker impedance may be much lower than the rated "nominal" impedance at certain frequencies. The over-current fault detection circuits prevent potential damage that can be caused by driving very high signal levels into very low impedances. In STEREO mode, at full output, the current limit can be reached if the load impedance dips below about 1.3Ohms. In MONO mode, at full output, the current limit can be reached if the load impedance dips below about 2.6Ohms."

So if I do hit these limits then the amp will shutdown. I am assuming that VERY HIGH LEVELS means high volumes.

@jafant Congrats. 

I was going back and reading this thread starting where I join in with my drama.  I had remembered that someone who actually owned the 3.7 and 2 x AHB2's AND was a classical musician said that the single AHB2 was preferred over 2. I always like to hear what a musician thinks of gear because they have more experience in real music than me.

Here is some comments emailed to me from John Siau on the compatibility in relation to Stereophiles comments.

3.8 Ohms at -40 deg is not a problem. You will not hit over-current shut down, even in mono mode.

The maximum SPL in mono mode will be about 6 dB higher than stereo mode.

The unique thing about the AHB2 is that it stays clean when driving low impedances and difficult phase angles.

Anyways, there is enough info now in this thread on the 3.7 + 2 x AHB2 synergy that we can put it to bed. People can make up their mid based on the great comments here. I am sure people would like to get back to regular scheduled programming.

@tomthiel I also have a Sony SCD-1. I had it modified by this guy,
https://sublimelistening.com/

His work is amazing and I think he could be a great person to contact for you to see about repairing your SCD-1. The Vacuum State Mods he also does take this unit to an amazing level. I still use my player and it is great.

I am planning on using my player until it dies. I was considering buying some spare parts but then you do not know who will be round to fix it. The main issue with this player is usually the sled motor. You may have a backup of that part. I suggest you give Warren G a call and see if you can get your machine up and running. It is really worth it even after all these years, especially with the mods.

The mods are described in this review.
https://www.dagogo.com/vacuum-state-electronics-sacd-modification-and-sony-scd-777es-cd-player-revie...


I have the original packaging still but the foam is no longer functional so packing it for shipping will be a chore. I imagine this would be the same for all of us with the original packaging.

@hifi28 In my even smaller room I got the CS3.7 to work very good and this was with a nightmarish COAX situation (slowly resolving). My room is acoustically treated. I know almost all the posts on A’gon say the CS3.7 requires a fairly large room, I think there are ways around that. I have photos on my virtual system.

Yesterday, I thought I would see how loud I could crank the CS3.7 for 1 complete song (without lowering the volume). I only got to 85 dB on my iPhone meter. In a larger room I know for sure I would have had it much louder, based on past experiences with other speakers in bigger rooms. Makes me wonder if I should be happy with a single AHB2 (something like 292@2 Ohms) . I have not tested out if more wattage is helpful in low volume scenarios. That is last on my ToDo list.

As an update on my journey.

1) Today I fixed the broken COAX screw thread on the frame using the RECOIL kit recommended by Rob Gillum. Great stuff.

2) I bought 2 black COAXs from Rob yesterday. They may arrive before Thanksgiving but I will use the time to do #3.

3) I just bought some water based stain to put on the speaker. Now that the COAX are removed it was easy to carry the speaker to the garage to sand it down and then add 3 coats of the stuff I just bought.

One of the COAX’s was first out-of-phase. I fixed that and it sounded much better. Then today after testing the circuits with an Ohm meter I am almost 100% certain that the crossover wire for the midrange was connected to the tweeter and crossover wire for the tweeter was connected to the midrange. I have not confirmed with Rob Gillum yet. The second situation is supposed to be very very bad. I am assuming the tweeter on that COAX is damaged. The measurements did show that there was a problem on the high frequencies. This was not the fault of Thiel it was a DIY issue.

Getting close.

Does anyone have any info on the woodwork on the CS3.7? Is it solid wood or is there a veneer on it? I will talk with Rob Gillum next week or the week after Thanksgiving. In the meantime does anyone have any info on the wood panels. I would be interested to hear some feedback before I get too deep in the restoration work I am doing.

I am in the process of refinishing the wood. Rob told me to use 220-320 grit sandpaper to clean up the existing lacquer. I forgot to ask him about the composition of the wood.

Part II - This internet thing is so useful. 
http://www.theaudiobeat.com/visits/thiel_audio_carries_on.htm

@thieliste I know about those 2 DACs. I am looking at a bit lower cost, so the Halo Spring Level 3 and the Denafrips Terminator +.  If I were to spend over $10K (I won't for a DAC) I think it would be the non-R2R Mola Mola Tambaqui. I have spent $1580 on a new Benchmark DAC3B and I have no complaints other than needing a second DAC in the future.

I was also waiting on the new Luxman chip based DAC that is in their uber SACD player. The specs are amazing and the sound is supposed to be very analog. My main thing nowadays with electronics is that they have to be close to as quiet as my Benchmark HPA4 preamp. For me that makes all the difference in the world because I can hear the silence.

@unsound  That harlequin effect is beyond my brain power. I looked it up online but could not find anything about it. In University, I took a class on some subject that discussed  the following book,

https://www.amazon.com/Visual-Display-Quantitative-Information/dp/0961392142/ref=sr_1_2?dchild=1&...

There were some very interesting visualization issues described in that book. I still have that book and tried to look up the harlequin effect, no luck.

I was also surprised at the amount of content from China on the CS3.7. I thought they built the COAX in house but Rob mentioned something about getting shipment of drivers and why they have the black coated new ones. I did not ask more questions on that but that article makes it clear. As does the fact that it is laminate with a veneer.

I am also looking at an R2R DAC for the Thiel system and I have 2 Chinese made DACs at the top of the list. So I have no issue with audio gear from China. I want to get my bedroom headphone system rebuilt so I can use my Benchmark DAC3B or the second DAC for that.

The previous CS3.7 repairs were not done by a repair person. It was done by the previous (or first) owner. The dealer seems to have also opened up the COAX driver screws to have a look inside and had over torqued the screws to break the threads (just fixed by me).

At the moment I have the COAX drivers off and the woofers and other parts covered nicely for sanding, staining, or if I get brave, painting. As I mentioned before it is so much easier to carry the speaker with the COAX removed.

The cherry color I have is nice but I always wanted something a little more distinctive for the office. When I was considering the Paradigm Persona 3F I looked at the customer color configurator and came up with a few color combos that I liked. I use the grill at all times (my 4 year old has never seen the drivers).

https://design.paradigm.com/en/persona/customize
Carbon Black Gloss (saw this in person)
Burnt Orange (I loved the KEF Blade in orange)

My new neighbor has a beautiful matte brown colored Mercedes. I was think of painting the cherry to a matte black to perfectly match the top aluminum shell which has been recently spray painted by me. I think it may look good with the black grill on. Just thinking out loud at the moment.

@tomthiel I have been in contact with Rob and I have already done the multimeter test. I think the wiring was revered both on the wires coming out of the crossover and also the connection to both midrange and tweeter terminals. A real mess up. I have not confirmed the wires coming out of the crossover yet with Rob but based on the Ohm numbers recorded and what Rob told me to expect, it looks like it was wired in the wrong manner. So I believe my COAX is damaged. I just bought 2 new black COAXs from Rob last week and will have this issue put to bed. What a nightmare.

@unsound Yes, I over thought it. I must also say I am not the biggest fan of that contrast either. I am likely going to do a solid matte paint job in the upcoming week.  

I just found some photos of a Satin Black CS3.7 and it does look real sharp.

https://img.usaudiomart.com/uploads/large/2089598-1d5bad0b-thiel-cs-37s-satin-black-wtheir-original-...

I am going to the paint store today and will decide between the Satin Black or a Matte Black that perfectly matches the aluminum shell that I spray painted with Krylon Acrylic Lacquer paint (#1613).

That 15 x 20 room sounds ideal for the CS3.7. 

I had a Bryston 3B-ST and a 4B-ST and they were a little hard on top. I would not like it paired with my current 3.7. I also had a 7B-SST and even that was a little strong on top and I would not pair it with the 3.7. I did pair the 7B-SST with the SCS4 and it was a little too bright on top. I believe the SCS4 and the 3.7 has similar COAX drivers (maybe not the same). I get fatigued easily so others may not have a problem with the ST or SST. 

If you wait a few more months the Purifi modules with 1000 watts into 2 Ohm should be released by Bruno et al. The goal of these Class D amps is to remove a 0 from the price of amps. It should be a great match with the 3.7. The NAD M33, which was Stereophile's 2020 product of the year, has the first iteration of the Purifi module. 

Other manufacturers are pumping out quality Purifi amps for $3K and under price. I am waiting on the next more powerful Purifi amp for my 3.7's. They are supposed to sound like my great Benchmark AHB2 amp.

I used to own the A23 with Thiel SCS4 (also Bryston 7B-SST) and it was a very warm sounding amp. I think I prefer the more neutral sounding amps with the CS3.7.

https://www.parasound.com/a23.php

NAD M33 - I may have a listen to this tomorrow at the local shop.
https://nadelectronics.com/product/m33-bluos-streaming-dac-amplifier/

NAD has 2 more Purifi products a 7 channel and a pure 2 channel. They are working in close collaboration with Purifi.

I spoke with the owner of March Audio in Australia and they are given high marks on ASR web site for quality products. I was thinking of getting this but went with the Benchmark AHB2 before I bought my CS3.7.

https://www.marchaudio.net.au/p451

There are other Purifi based amp builders, The ASR web site has good discussion on these other manufacturers.

I was discussing amps for the CS3.7 with a guy from Brazil who has the CS3.7 and has tried a few amps with them. He is also waiting on Bruno to release the next iteration of the more powerful Purifi modules. For me, after the AHB2, any future amp has to be silent.

I started a thread on A’gon earlier in the year titled, "Removing a zero from the price amps". A lot of info posted on that thread about Purifi.

https://forum.audiogon.com/discussions/removing-a-zero-from-the-price-of-amps?highlight=removing%2Ba...

A guy in Rochester NY is selling a CS3.7 for $4K but it is local pickup.

Status update on my CS3.7 refurb.

1) I was able to contact Rob Gillum today and we discussed the resistance measurements on my crossover. One speaker, the good one, had 0 resistance on the tweeter, What the heck happened there. I was thinking I would need to disconnect the crossover and send to Rob. Not something I wanted to do.

However, after opening up the crossover module I see the white positive tweeter wire disconnected from the crossover. Maybe it got disconnected when I moved the speaker to the garage for painting. I did use kid gloves with the transport but maybe not careful enough. This speaker was the one that was measuring stronger on the high frequencies on the SPL measurement. So the wire must have got disconnected after the measurements. The re-soldering of that tweeter wire was tricky but got done. I measured the resistance again and everything was good on both speakers.

I added the 2 new COAXs that I got from Rob. They are the black ones from 2014. I packed up the old COAXs to send to Rob for analysis. If they are good they will be my backup drivers.

2) I finished the paint job. It was a 9/10 until I became more ambitious and decided to touchup a smudge on the aluminum shell of one speaker. I added some of the great 3M painting plastic to cover the wood in a small section. Painted it and came back the next day to remove plastic. Unfortunately, the tape on the plastic stuck too tightly on the new paint on the wood and took some paint off. Awww!. I fixed that with some sanding and touchup but now that side is a 7/10. I can fix it perfectly with some sanding and a full coat on that side but you can only see the touchup if you look closely from an angle. Maybe I will fix that but for now I have the speaker placed so that I never see it.

3) I added the new outriggers I got from Rob,. I like the way that looks and functionally useful so that my son does not topple the speaker. I managed to do all of this work without my son seeing what the drivers look like. Which is a good thing.

As I listen to some John Lennon, the sound now seems correct. I was told that the new COAX needs about 200 hours to settle. However, given the massively messed up nature of the speaker when I brought it home, it sounds the best I have ever heard right now. The COAX is not as smooth as it will get but it sounds so much more coherent across all the frequencies. A bit like the Yamaha NS5000.

All of this cost me about $2000 extra. With paint, 2 new COAX, outriggers, solder kit (and self training), multimeter, and the Recoil kit to fix the COAX thread. What a nightmare but a great learning experience on speaker builds.

I will measure the speakers next week and hope the results are perfect. If so, I can continue with my DRC implementation.

I took some measurements with the miniDSP mic and REW software to see if the new COAXs I installed (plus other wiring fixes) have resolved the SPL issues. I now see a beautiful LEF and RIGHT measurement chart with everything overlapping, just like my KEF LS50’s. Halleluiah!

So my take away from all of this for any one looking to get a CS3.7. Even a massively screwed up one like mine. The speaker can be made perfect using Rob Gillum as a resource. All this work was done at home by me who is a novice on electronics.

I jumped the gun and decided to contact AccurateSound.ca to do the DRC from my ROON based music (not my tuner or SACD player). My speakers have 2 brand new COAX drivers with less than 10 hours burn-in, I was told 200 is needed. So far, with these new drivers, my system has sounded the best. Which makes sense after fixing all the damaged driver, wring, and air leak issues. So I decided to jump the gun and see what Mitch Barnett could do with system in it’s current form.

I sent him the measurements that he needed and a few hours later he came back with the first of 6 Convolution filters. This is a computer zip file that gets loaded onto the ROON server to act as an software equalizer before my digital data hits the DAC. The goal is to create a sound curve that is optimized for my room and sitting position.

I have a big speaker in a small room and I sit slightly to the left side of the sweet spot. Mitch created a filter using the Audiolense software (he also works with Accurate, but not in my case).

The first filter he sent me was jaw dropingly great. I was floored how perfect the sound was. I am listening to a bunch of different music to come up with ideas for the other 5 filters, but really having a tough time figuring out what needs improvement. I suggested another filter with a bit more bass. He also suggested something that fits the Harman target curve. We will figure some new ones on Monday.

I am currently listening to Santana’s Woodstock recording. I listened to it at a dealer on Wednesday. It was on a $32K Paradigm Persona 9H speaker + Mark Levinson gear. The bass was way more powerful (and incredible) than what I have with the CS3.7. However, there is no contest on the COAX vs the Be drivers on the 9H. I think the 9H was not setup well in the room, because I have heard the 3F and 5F sound better than this 9H demo, but nevertheless I love what I am hearing today with the CS3.7.

This office system I have is now perfect.
https://systems.audiogon.com/systems/7605

As an FYI. Here is a link to the technical details of what I described in my past post on this thread. The author of this article is the person who did my DRC work. He is a big fan of Thiel's and used to own the CS3.7.

https://audiophilestyle.com/ca/bits-and-bytes/what-is-accurate-sound-r923/

I do not need more power, a single stereo AHB2 is great. That $700 I spent on the Convolution files creation saved me $3K or $6K on a new amp.

@tmsrdg https://www.audiosciencereview.com/forum/index.php?threads/did-you-audition-nc500-vs-nc500mp-or-nc50...

I just got my 3rd Convolution filter from AcousticSound.ca. I now have found the perfect frequency curve for my speakers and room. I lose 10 dB of gain by running the Convolution filter in ROON but my preamp (HPA4) has a 10 dB boost feature. ROON also has PROCEDURAL EQ which allows you to reclaim that lost gain. I decided to use my premps boost instead (I could use both).

Remember, my posts about the AHB2 not hitting hard enough. Well with the drivers and the wiring fixed. With the gain boosted and mainly with the Convolution filter. Things are really rocking. A big speaker in a small room sounding like it is now is incredible. No fatigue at all.

I also spoke with Benchmark technical support because my preamp had a glitch on the boost adjustment (we fixed with a factory reset of the GUI). They also said that 2 mono AHB2 can put out 700 watt at 2 Ohm. They cannot publish this because the amps cannot run like that for extended time. They also said the mono amp is stable to 1 Ohm. It also has the forward correction to stop clipping to get to the speakers. Just an FYI.

Wow, just so happy with what I am hearing today. The CS3.7 has never sounded this good in any dealer demo I went to with much more expensive gear.

@tmsrdg Oops, forgot to answer the question about the boost adjustment. My HPA4 had the boost disabled on XLR1. XLR2, RCA3, and RCA4 all worked. I worked it out with Benchmark tech support. We ended up doing the FACTORY RESET on the GUI. I lost some settings but not big deal to manually restore them. I think I may have seen this before.

It was important to get the 10 dB boost today because the Convolution adjustment took away 11 dB. I learned a about ROON DSP settings the past few days. There is boost in the ROON settings too but as of now I have disabled that.

@tmsrdg I know you had a single AHB2 and are also a musician. I was thinking why does my system sound bad and yours so good with a single AHB2. There were hardware issues for sure but the room was still a big impediment for me.

Here is a link to a post I made that digs deep into what I did.
https://forum.audiogon.com/discussions/room-correction-roon-rew-room-eq-wizard/post?postid=2064340#2...

Here is a another post I made that has a bit more info.
https://forum.audiogon.com/discussions/speakers-good-for-close-to-wall-placement/post?postid=2065116...

The ComputerAudiophile.com site is were this advanced DSP stuff gets chewed around more than here on A’gon.

All I have to say is this Convolution engine in ROON is brilliant stuff. Just transformed my system. If you want to see some graphs send me PM and we can do that by email. Don’t tell anyone since email is not allowed.

@tmsrdg A shame you cannot use ROON (or JRiver). The Convolution file optimization is incredible. It fixes the room which I think is always the biggest hurdle to great sound at home. For me this a likely a bigger hurdle than most, because of the big speaker in a small room.

I had 3 filters made for me. The first was very good but needed a bit more bass presence. So I received a 2nd file that had a slight boost from 100 Hz down. That gave me a slight irritation in the ear. So we made a 3rd file that was half the bass adjustment between 1 and 2. This was the goldilocks filter, It was just right. This showed me it was not the amp that was deficient it was the room.

Today, I just found some extra money to buy some audio gear but I now have no need for anything. I was thinking of the Halo Audio May Level 3 DAC that people are raving about but I have 0 desire to change what I am hearing. This Benchmark stack is amazing. I currently streaming some 70’s BeeGees, with their huge bass lines, it sounds so good without fatigue.

Last thing about Convolution filters and then I will stop.

I am listening to some rock music now, Robert Plant and Rainbow. I was starting to feel sleepy when I was listening. This used to happen prior to the Convolution implementation (too much sound pressure). The imaging was also off and the sound seemed to be coming from the speakers instead of the speakers disappearing. I thought these are old recording and maybe that is how they were recorded.

I must have had a brain freeze since I was under the impression that I had turned ON the Convolution. It is very easy to see on ROON current track being played. However, it turned out that I have not enabled the Convolution because I had listened to headphones the prior night. I think I was fascinated by the new MQA DAC setting in my sound path and did not notice the Convolution was missing.

I turned ON the Convolution and the pressure that was making me sleepy disappeared, the speakers also disappeared, and the imaging became great. This is some great technology. OK, no more on the Convolution stuff.

I asked a dealer about the #16 last week. He sent an email to CODA to ask about the specs on the #16 at 2 Ohm.

Yesterday, I was reading something online (I forget exactly what) about the CODA #16 and that post or review said the 100 watt Class A is for both 8 Ohm and 4 Ohm.

I received an email from Doug Dale of CODA (info@coda.cc) on the #8 and he said that that unit halves the Class A output as impendence is halved.

Now that I am set and amplification on the CS3.7 (Benchmark AHB2) I am looking around for an amp for the KEF Blade 2 that I will get in 2021+. The CODA is a consideration. It could also be swapped with the CS3.7.

Now back to my CS3.7 in my office. What a great speaker. I think my new COAX drivers are breaking in now. Just an incredible sound, this is some of the best sound I have ever heard from any speaker. I have heard quite a few the last 10 years. Luckily, I do not have much work to do for my job because right now the music is too distracting for me to concentrate on any work.

I have a CODA dealer 100km from me (so very close). They also said they allow home demos of their gear. I may have a listen once COVID is taken down. The thing that intrigues me on the #16 over the #8 is not the Class A, it is the SNR of 130 vs 118.

The Luxman m900u (12 watt Class A), which I thought was amazing with TAD gear, has similar specs to the #8 (18 watt Class A). The #8 is supposed to sound like the m900u but at 1/3 the cost.

Why not get the Diablo, if you decide that you do not like it you can easily sell it since it is so highly regarded.

@yabe1951 That is the correct way to unbox them. I helped pack my 3.7s from the previous owner and also unpack them at home.

Even though the speakers are not really that heavy for speakers I recommend you get some help to carry them some distance. I had to take them up stairs and then back down and up again. A real pain, It is easy to press on the COAX drivers if yo are not careful. When I removed the COAX drivers (they were messed up) it became so much easier to carry them up and down the stairs. When you carry these speakers by yourself, your hand naturally gravitates to the area where the COAX reside.

Some testing results with the AHB2 (in mono) and CS3.7 from last night.

https://forum.audiogon.com/discussions/what-is-floyd-toole-saying-about-extra-amplifier-power-and-he...

Have a look at the AudioByte VOX | ZAP | HUB (1 power cord needed for all three same units. This is going to be my next DAC system ($6K). It will start to get more press in the future. An initial slow burn of awareness  like the Mola Mola Tambaqui that everyone is now raving about. I am keeping my Benchmark DAC3B but will also have a second with the AudioByte stack. The tech in that is incredible.

@sdecker Congrats on the LS50 Meta. All the comments I have read on it indicated a very nice performance improvement. The Meta are doing something like what Vivid Audio is doing but likely more advanced. I wonder if the rear cancelling Meta allows closer front wall placement. Reviewers usually do not give this valuable info.

I am deciding on the Yamaha NS5000 or KEF Bade 2 for my downstairs system. Buying this is all dependent on a stock investment I made. A few years ago I sold my old stereo system and put it into this stock. So if it hits I will spend a bit of money on the living room system without anxiety.

I am waiting on KEF to trickle up the Meta tech to the Blade 2. I am under the impression that is in the works. Blade 2 are going for half price used now and is the smarter buy but this next 2nd system is not about being smart.

USAAudiomart is free and rather good for selling. Though last night I put up an ad for a WANTED AHB2 amp and I got a scammer redirect me to his/her web site to scam me. I figured it out after some customer support conversation with someone in this group. However, for selling, USAudiomart, is very good. A’gon is also still pretty good.

That Benchmark system in TAS is my system, except I sold the DAC3B last week. I will buy it back later in 2021 since I already miss it.

I also did a test with a single AHB2 and turned on mono operation to get more power. I then ran it on 1 CS3.7 speaker. I liked it a lot more since I got more bass and things seemed more energized. So I bought a second AHB2 that should arrive in a few weeks.

@tomthiel The Benchmark preamp, preferably the HPA4 over the LA4 because of the bonus headphone amp. I hated headphones prior to getting the HPA4. The Benchmark preamps also make their DACs sound better because the volume control on the preamp is much better. The preamps are quieter than the DAC3.

I am now thinking of trying out the RAAL SR1a ribbon headphone driven by 1 or 2 AHB2 amps (not the HPA4). RAAL used the AHB2 to develop the SR1a.

BTW - I have at one time owned, DAC1, DAC2 HGC, DAC3 HGC, DAC3B, AHB2, HPA4 and all Benchmark interconnects and now speaker cables. I love this gear.