CST-1 No-Res Question

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lincolnmat

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Re: CST-1 No-Res Question
« Reply #20 on: 11 May 2020, 02:49 pm »
I just spoke to Danny. He said NOT to take out the tile product that is already there. Just put the No Rez right on top of it.

He said to be sure to fill the space behind the woofers and especially to cover the top brace that is below the upper woofer. He prefers fiberglass to polyfil.

Groovin

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Re: CST-1 No-Res Question
« Reply #21 on: 11 May 2020, 06:52 pm »
I just spoke to Danny. He said NOT to take out the tile product that is already there. Just put the No Rez right on top of it.

He said to be sure to fill the space behind the woofers and especially to cover the top brace that is below the upper woofer. He prefers fiberglass to polyfil.
. Awesome thanks for the information.   :thumb:


lincolnmat

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Re: CST-1 No-Res Question
« Reply #22 on: 12 May 2020, 07:13 pm »
It may not be Danny's favorite device, but the only tool I have is MiniDSP with REQ.

I have done the crossover upgrade on both speakers, but have only added No Rez to one speaker. I did a 20-20K Hz sweep of each speaker on the same position in the middle of the room keeping everything else the same. The Red line is the speaker WITHOUT No Rez, the orange line is the speaker WITH No Rez. Interesting that bass and treble both improved.




corndog71

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Re: CST-1 No-Res Question
« Reply #23 on: 12 May 2020, 08:21 pm »
It may not be Danny's favorite device, but the only tool I have is MiniDSP with REQ.

I have done the crossover upgrade on both speakers, but have only added No Rez to one speaker. I did a 20-20K Hz sweep of each speaker on the same position in the middle of the room keeping everything else the same. The Red line is the speaker WITHOUT No Rez, the orange line is the speaker WITH No Rez. Interesting that bass and treble both improved.


The most important question is how does it sound to you?

lincolnmat

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Re: CST-1 No-Res Question
« Reply #24 on: 13 May 2020, 12:50 pm »
Yes, the sound quality is whats important. But I was so exhausted after finishing the speakers that I just did some non-critical listening and rough placement until I was ready to drop. Left them running overnight and went to bed. I will make final adjustments today and give some feedback.

I was also too tired to post these pics last night. Since I showed the internals pre No Rez before, here are the after shots. Apologies for some rough edges to the No Rez, I was using a long bladed box cutter to make the cuts.










I forgot to take pictures after I put the stuffing in. I put lose fiberglass behind the top woofer and reused all the poly fill for the rest of the placements. I might get more fiberglass at some point to use that everywhere, but for now all the spaces Danny listed are stuffed.

Matt

lincolnmat

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Re: CST-1 No-Res Question
« Reply #25 on: 13 May 2020, 12:53 pm »
Forgot to mention how horrible the press on connectors were. Danny wasn't kidding when he mentioned them in the video. Several actually broke when I took the drivers out and a couple pulled off on their own. I was able to pull all of them off pretty easily by hand.

AverageNiceGuy

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Re: CST-1 No-Res Question
« Reply #26 on: 13 May 2020, 02:22 pm »
Very cool,  8)
Thank you very much for sharing the pictures.
This will help me for courage to tackle into my CST's / NoRez / Caps this weekend.

Danny Richie

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Re: CST-1 No-Res Question
« Reply #27 on: 13 May 2020, 04:15 pm »
Forgot to mention how horrible the press on connectors were. Danny wasn't kidding when he mentioned them in the video. Several actually broke when I took the drivers out and a couple pulled off on their own. I was able to pull all of them off pretty easily by hand.

Oh yeah, I hate those things.

And nicely done.

lincolnmat

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Re: CST-1 No-Res Question
« Reply #28 on: 13 May 2020, 06:41 pm »
Thanks Danny!

The No Rez made a big difference. I played some deep organ music comparing the before and after speakers (played it mono) and you could hear much better clarity to the low notes in the speaker with the No Rez. Still tweaking the final position and not ready to make a final evaluation.

lincolnmat

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Re: CST-1 No-Res Question
« Reply #29 on: 17 May 2020, 04:17 pm »
Let me start by saying that I have owned planar speakers exclusively since I bought my first pair of Magneplanars in 1986.

As soon as I saw Danny's video about the Carnegie CST-1s, I figured I needed to try them.

1. With the current lockdown and lack of GR Research speakers available for audition near me, I wanted to actually get to hear one of Danny's designs.
2. I wanted to see what an upgrade package could do to an existing speaker.
3. If I didn't like them I figured I could use them in a secondary system, or take them to my brother's house so I could have something to listen to when I visit him.

I'm glad I jumped when I did because Danny sold out before the end of the day I called.

I did listen to the unmodified speakers a bit to get a handle on the sound. They had promise, but I could detect some of what I don't like about box speakers. Was that some internal resonances? I'm sure it was.

I upgraded the crossovers first as I waited for answers on the use of No Rez - the purpose for this thread. I heard some detail improvement, but possibly too much as they became a bit bright. I initially had towed in the speakers and reduced that to get a better balance.

Once I finished the No Rez I listened again. I could detect much less boxiness. One of my reference recordings is the organ transcription of Pictures at an Exhibition by Jean Guillou. The deep organ notes were much more focused and solid. That even improved more once I put the last bit of No Rez in the chamber inside the lower port. I needed to clean out all the built up dust in the bottom of the speaker first and had been too tired for that when I tried to finish the No Rez the night before.

Once fully finished I began to listen more carefully. I had kept the speakers playing as much as I could since I got them to break them in. They had just been sitting in the room and I realized that sitting on two levels of carpet was not letting the speakers get enough floor loading - they were vibrating on a cushion of carpet.

I made the time investment to disassemble my Apogees and loaded stands. Being in my main speaker position really helped. I then added the spikes - I didn't want them on my good oriental rug. The speakers were still floating a bit until I added the spacers that allowed the points to dig down into the deep shag rug that is the lower layer in my room. Finally the speakers were on a solid foundation.

They were still sounding a bit "nervous" and bright. Possibly this is a factor from my years of listening to planar speakers that aren't known for the greatest dynamic swings.

I continued to let the speakers run overnight.

With somewhere around 150 hours of running, the speakers are finally coming into their own. I never thought I would like a box speaker this much.

I have always lived in fear of some of the organ music I like might eventually make the bass panels of my Apogee Stages rip apart. They made some protest if I turned up the volume too much. The CST-1s just take it in stride. I am amazed at the amount of bass these 5.25" drivers are capable of. A testament to Danny's transmission line design.

With more time on them, the "nervous" character is now gone. I won't say that they sound quite as effortless as my Apogee Stages on mid to high frequencies, but they continue to get much better. I just played the Les Brown direct to disc record I have had since 1978 and I don't have anything to complain about. It is clean and dynamic and free of almost all colorations - a window into the performance.

With the amount of effort needed to swap speakers, I am going to keep the CST-1s in place for a while to see how they continue to progress. No speaker is perfect, you have to balance all the factors. I like what I am hearing and if they continue to improve with more playing time, they just may be my new main speakers.

Equipment makes a big difference, so here is what is driving the speakers.

Turntable: SOTA Star Sapphire, SME 309 arm, Dynavector XX-2 MkII cartridge
Electronics: Audio Research LS-27 pre, PH-6 phono, DAC-8 for digital. Rogue Audio Medusa power amp
Wire: Kimber Select KS-1116 interconnects and 12TC speaker wire

If there is anything holding the new speakers back it might be the amp. It is way more than needed for these speakers. I needed an amp with lots of gain and watts for the inefficient and power hungry Apogees. Another lower gain and sweeter amp might be an even better mating.

As a comparison (not fair, but I'll make it): I gave a friend a pair of ELAC Debut 6.2 floor standers several months ago. While they are decent. They still sound boxy and these CST-1s are completely in another realm of sound. They should be for their retail price, but at the price I got these - and a bit of effort. They are stunning.

mlundy57

Re: CST-1 No-Res Question
« Reply #30 on: 17 May 2020, 07:00 pm »
Glad you like them.   :thumb:     Even though I have the open baffle NX-Otica MTM/OB sub combo upstairs, I'm still amazed at how good the N3s in the living room system sound.

Mike

AverageNiceGuy

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Re: CST-1 No-Res Question
« Reply #31 on: 17 May 2020, 10:40 pm »
Thank you for the updates guys, I'm very excited to upgrade mine. I can't find my soldering iron darn it, I'll need to borrow one from work :-)

AverageNiceGuy

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Re: CST-1 No-Res Question
« Reply #32 on: 23 May 2020, 05:17 pm »
Hah, I'm glad I sent you the link for the NoRez.
I'm using your post to get the picture again.
I'm starting the NoRez job now on mine.
http://gr-research.com/pdf/carnegie%20stuffing%20issue.pdf

lincolnmat

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Re: CST-1 No-Res Question
« Reply #33 on: 27 May 2020, 01:22 pm »
Major update!

Turns out the CST-1s were being unfairly hampered. I began to realize a slightly shouty midrange with female and higher pitched male voices. I was also experiencing a lower than expected warmth on recordings that should have it.

Turns out I needed to replace the tubes in the driver stage of my amp! The Mullard ECC82s had been in the amp for more than a year and were getting tired. I put in a set of Brimar CV4003s tubes I had from a preamp that I sold. BIG IMPROVEMENT.

Sweetness and ease greatly improved. My Rogue Audio Medusa is similar to Mike Lundy's new PS Audio amps in basic layout. A Class D output stage mated to a tube input and linear power supply. Yes, Class D is capable of sweetness and detail without sounding edgy. The downward performance of tubes are subtle enough that it can take a while to realize what is missing.

I am now much more impressed by the CST-1 speakers than before. I'm going to have to re-listen to some of the recordings that I had used to evaluate them up to now. The ones I have tried so far sound dramatically better!

I'm even more impressed by the bass tone of the two 5.25" woofers than before too.

Matt

AverageNiceGuy

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Re: CST-1 No-Res Question
« Reply #34 on: 27 May 2020, 03:54 pm »
That is good to hear lincolnmat,

I'm enjoying reading your info and updates on the CST-1's compared to other speakers, and with different equipment.

I've got both mine upgraded now, and I'm getting in some listening time in before changes of speaker wire, sources, and possibly an amp.