Documenting: My SDA-1c upgrades from start to finish
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plastic_avatar wrote: »skipshot12 wrote: »That 2250 is no slouch.
Another one to bi-amp and you's be all set.
I wondered what it would take to make the crossovers bi-ampable... but I didn't want to start that potential firestorm yet [laughs].
Out of the equipment I've been able to afford over my life, the P2250 + the HTR-5960 as a pre + my sturdy ol' Nakamichi CD is the best combo I've had to privilege to own.
Since losing my job at the place I worked at for almost half my life (during year one of the pandemic), and spending the next year and a half under and unemployed, I'm so very, very pleased I have what I have now. And grateful to have what I have for myself and my family.
Between my thrifting and the generosity of friends and near-strangers, I built up a system that I am proud of. My dream amp since I was 13 was the home version of the P2250 (with the Knight Rider red light bars). That I have the roadie version makes me happy. It only took... oh... 39 years to get it
And I get to continue to share listening to a stereo with my daughters. Only now with 100% more SDA W-O-W.
Over the past, I dunno... 8 years? I put together and gave away at least 6 stereos for friends and co-workers (a wedding present here, a going-to-college dorm rocker there, and systems for people who needed cheering up, or could use a little boost during a rough patch). I've also given away separate sets of speakers, turntables, and CD players to people who are not as fortunate as I am. Friends and family know I do this, and they'll sometimes donate to the cause if I'm searching for a piece to complete a setup for someone.
So, yeah. The P2250 is no slouch.
I listened to it tonight with a friend who is a Definitive and Adcom guy. He was impressed by the sound. We enjoyed talking about how the vibrations of strings sounded on Hotel California and Wish You Were Here. It was great fun. The soundstage blew him away. I'm still in shock by it myself.
And I thank you for your contribution to this wonderful experience, Skip!
I'm totally making a list of all the people who helped (and how) to put on a paper to seal inside the cabs. I might 3D print it for durability. Like a kind of plaque.
No worries on the bi-amping.
Didn't know the speaks aren't bi-amp capable.
Disregard. -
I tried looking again to no avail. Someone here (Inspired Sports?) made a thread about TL-ing (RD0198) a set of SRS-2s and that was what I think would be the way to TL mod the 1C's by replicating his SRS-2 tweeter schematic.Don't take experimental gene therapies from known eugenicists.
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At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?Expert Moron Extraordinaire
You're just jealous 'cause the voices don't talk to you! -
^ Could be said for any mod I reckon…
Once we do our first mod we’ve taken away from the original.
Comes down to individual tastes & perceptions at that point. -
At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?
That's like asking why I would drop an LS1 in a Porsche and keep adding heads, cam, long tube headers, power steering delete, carbon fiber hood.....yada yadaDon't take experimental gene therapies from known eugenicists. -
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At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?
That's like asking why I would drop an LS1 in a Porsche and keep adding heads, cam, long tube headers, power steering delete, carbon fiber hood.....yada yada
No it's not.Expert Moron Extraordinaire
You're just jealous 'cause the voices don't talk to you! -
At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?
That's like asking why I would drop an LS1 in a Porsche and keep adding heads, cam, long tube headers, power steering delete, carbon fiber hood.....yada yada
No it's not.
Well let's keep it audio-related so you may comprehend the analogy.
Why would @ptrooper take a set of factory 1.2TLs and produce The Monoliths?Don't take experimental gene therapies from known eugenicists. -
At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?
You can ask almost any "Heritage" Klipsch owner.
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I've modded about as much as anyone, and it all depends on the goal. Mine was to wring performance from old speakers with design shortcomings that I've kept for sentimental reasons. I don't mind if they've become FrankenPolks as long as they sound right. I've enjoyed the process, and did the "tried and true" mods first, and later did the more controversial ones "one at at time" with months of skeptical/critical listening between. I've had lots of experience with live music and if something sounds wrong, or ineffective I undo it (granted, undoing some mods is more easy than others). I've hit optimal sound at this point and am reticent to do much more. I might get @xschop to countersink the screw heads on my tweeters (diffraction).
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At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?
That's like asking why I would drop an LS1 in a Porsche and keep adding heads, cam, long tube headers, power steering delete, carbon fiber hood.....yada yada
No it's not.
Well let's keep it audio-related so you may comprehend the analogy.
Why would @ptrooper take a set of factory 1.2TLs and produce The Monoliths?
Wow.
Really?
Hit a nerve, huh?Expert Moron Extraordinaire
You're just jealous 'cause the voices don't talk to you! -
If you're too nervous to answer the question, I understand.Don't take experimental gene therapies from known eugenicists.
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I'm afraid the Smithsonian isn't going to want these speakers anymore
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
Two (or more) things can be true at once:
1. They sound fantastic to the owner.
2. They ceased being “Polk” speakers long ago.“Human beings are born with different capacities. If they are free, they are not equal. And if they are equal, they are not free.”
― Aleksandr Solzhenitsyn -
At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?
I understand that. 100%.
So far, there haven't been any sound-altering nor SDA-affecting mods that fundamentally change:
- speaker layout and orientation
- box design
- crossover design
- speaker type
- speaker design intention
To me, those 5 are the big ones as to whether the speaker starts to become something new, rather than an evolutionary iteration.
Everything so far is an update to the original release.
If I changed the driver layout to mimic an SRS, whether that's positive or negative, it would be a major release. And the more major releases from the original you get, the more different the product becomes.
Anyhow.
I've thought about it more than a little, so high five. I get it. I do
v1 = stock
Changes that don't affect versioning:
- new gaskets
- crossover replacement, not upgrade
- anything else that is new, but close to stock, like driver replacements.
Off the top of my head, I'd add a .1 for each of these primary mods:
- 194 upgrade
- better caps/resistors
- dynamatting baskets
- foaming baskets
- phase plugs
- wiring upgrade
- terminal plug upgrade
- spikes
- BlackHole5
- felt around tweeters
- felt around mids
- edge diffraction mitigation for cabs
- Wuhan upgrade
- SDA cable/plug upgrade
- semi-rings
- bracing
- upgraded inductors
- cab treatments for resonance
Add a .0.1 for each of these secondary mods
- gluing magnets
- removing polyswitch
- replacing polyswitch with resistor
- additional cab sealing
- gimped or custom board work
- custom functional work, like custom terminal plates
- custom tweaks to 2000, 194, or Wuhan (.0.1 for each), such as: custom plates, custom backwave/felt plugs, ferrofluid, etc.
- Hurricane nuts/bolts
Anyhow, as is, I think it' maintains the soul.
If I forgot mods in this train-of-thought blurt, let me know.
Gives me a 1.12.6The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * custom 5B on a system for my Dad * Ye Olde college stereo in the garage -
The phase plugs alone are SDA-affecting mods that fundamentally change the performance as documented by a very well respected member.
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Why would you need dynamat on the driver baskets if you are just going to foam them?
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The phase plugs alone are SDA-affecting mods that fundamentally change the performance as documented by a very well respected member.
DK did a partial test, right?
When I say fundamentally, I mean changing the [insert aspect here] into something new.
A mod that gives a positive or negative by degrees, using the same setup, is not fundamentally changing the original into another full step on the versioning track.
As suggested by me, off the top of my head.
If we want to play with how I think about it, let's do it
I'm up for changes on this made-up list of mine, if you want to help me tweak it. Seriously. Anyone with suggestions can chime in on Steve's-internal-versioning-rubric.The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * custom 5B on a system for my Dad * Ye Olde college stereo in the garage -
I wonder how phase plugs does effect the SDA drivers?
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I wonder how phase plugs does effect the SDA drivers?
DK was dissatisfied with his imaging after vs before and felt he lost some magic. There may have been a problem with suspension sag in one of the drivers. There may be issues in a CRS+ with tweeter reflections off of the phase plugs especially with drivers so far apart and far from the tweeter. If so could be eliminated with a strip of acoustic foam like I did to my 7Bs in my thread in DIY section. Work in progress to see how they work in SDAs.
Steven certainly enjoys them in his 1C but doesn't have a baseline to A/B. We will probably (nudge!) try the acoustic foam strip on his to see if his imaging improves.
George / NJ
Polk 7B main speakers, std. mods+ (1979, orig owner)
Martin Logan Dynamo sub w/6ft 14awg Power Cord
Onkyo A-8017 integrated
Logitech Squeezebox Touch Streamer w/EDO applet
iFi nano iDSD DAC
iPurifier3
iDefender w/ iPower PS
Custom Steve Wilson 1m UPOCC Interconnect
iFi Mercury 0.5m OFHC continuous cast copper USB cable
Custom Ribbon Speaker Cables, 5ft long, 4N Copper, 14awg, ultra low inductance
Custom Vibration Isolation Speaker Stands and Sub Platform -
DK should add a felt pad around his tweets when he gets back around to doing audio stuff.
The CRS+ driver layout is the most distanced tweeter to mid layout of all vintage Polks. I didnt like it when I had a set.
The CRS soundstage was unnatural sounding and airy, to quote F1.. "a little TOO-wide" .Don't take experimental gene therapies from known eugenicists. -
At what point do "mods" to a speaker become so extensive and numerous that the speakers is so far from original design and intent that it can't be considered a modification of the original and is now something entirely different?
That's like asking why I would drop an LS1 in a Porsche and keep adding heads, cam, long tube headers, power steering delete, carbon fiber hood.....yada yada
No it's not.
Well let's keep it audio-related so you may comprehend the analogy.
Why would @ptrooper take a set of factory 1.2TLs and produce The Monoliths?
You’re seriously not comparing the work of ptrooper’s 1.2tl’s to these now are you?
You misconstrued that analogy. Just another way of saying the best vintage SDAs Polk offered are now THE BEST on the planet because the owner saw fit.Don't take experimental gene therapies from known eugenicists. -
DK should add a felt pad around his tweets when he gets back around to doing audio stuff.
The CRS+ driver layout is the most distanced tweeter to mid layout of all vintage Polks. I didnt like it when I had a set.
The CRS soundstage was unnatural sounding and airy, to quote F1.. "a little TOO-wide" .
So, you didn't phase plug your CRS or CRS+? It's unclear which you had.
There is a major difference between the CRS+ and CRS with the SDA tweeter, which definitely imparts an unnatural and airy artifact to the soundstage. The only cure is disconnecting the SDA tweeter. I never found the CRS+ to be unnatural and airy in the same sense as the CRS.
Are you thinking the phase plugs would shrink the "a little TOO-wide" as I noted? Ray definitely noted it did. Therefore, it seems the phase plugs are affecting the performance of SDA.
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I wouldn't be a bit surprised if it did negatively effect the performance of SDA.
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nm
"Appreciation of audio is a completely subjective human experience. Measurements can provide a measure of insight, but are no substitute for human judgment. Why are we looking to reduce a subjective experience to objective criteria anyway? The subtleties of music and audio reproduction are for those who appreciate it. Differentiation by numbers is for those who do not".--Nelson Pass Pass Labs XA25 | Galion TS P75 Pre | Holo Audio Cyan 2 Dac | MIT Shotgun S1 | Puritan Audio PSM136 Pwr Condtioner & Classic PC's | Legend L600 | Roon Nucleus 1 w/LPS - Tubes add soul! -
No I did not even contemplate phase plugs at that time. I had a set of CRS+ single tweeter that I customized after experimenting with driver spacing. The factory tweeter sounded very good close to the stereo driver. TOO AIRY in factory location.
I had a Bob Barker moment and traded them and moved on. I wish I had kept and plugged them because the MWs were also closer together, but not touching.
That said, if DK adds felt and still has a 7khz anomaly and loss of some center stage, then we can conclude that the plugs are not ideal in the CRS+.
I have recently held off plugging a set of SDA SRS-2s until this unknown is resolute.
If someone wants to try in their SDA-2Bs, I would be glad to plug them and revert them if they find similar issue..
I had converted my 8TLs to SDAs with phase plugged drivers and cabinets on their sides with incredible sound stage and imaging.
So I believe tweeter position to stereo driver is critical with the plugs.
Don't take experimental gene therapies from known eugenicists. -
I wouldn't be a bit surprised if it did negatively effect the performance of SDA.
If that's so, then that's amazing. The sound as they are is so wide. It's great hearing something that goes to the walls, and sometimes beyond them.
Thought that an evaluation someone could do would be:
- phase plug the stereo drivers, but leave the SDA drivers as-is, or
- plug only the lower stereo driver, etc.
The best I can do right now is to experiment with diffusers of some kind between the mids and tweets (and maybe mids and mids).
The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * custom 5B on a system for my Dad * Ye Olde college stereo in the garage -
Why would you need dynamat on the driver baskets if you are just going to foam them?
Matting on outside to dampen resonance.
Foam inside to help tame reflections bouncing off all those flat surfaces and back through the cone.The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * custom 5B on a system for my Dad * Ye Olde college stereo in the garage -
Well, I will say this for this thread -- it's led me to pull out the small but sincere collection of Neil Diamond LPs here and spin a couple...
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@mhardy6647 Surely there's a small craving for onion rings, peach pies, or culturally-significant hotdogs in there, too?
It's o.k. if not, but a lot of good came out of that section.
[goes to see if I still have that Neil Diamond CD that was in the sell pile]The Thrifty Setups in Mah House Big thrifty stereo in the basement w/ my custom SDA-1C (built with help from kind forum members) * Beautiful 1966 MCM GE console upgraded w/ Bluetooth, Dual turntable, and Paradigm speakers in family room * Swanky 1980 Realistic system and great TEAC eq with dancing colored lights in the living room * custom 5B on a system for my Dad * Ye Olde college stereo in the garage
