About finished tweaking my SRS's. They're now light, delicate and airy
candyliquor35m
Posts: 2,267
The soundstage and imaging is better than before. Dead quiet except for the music. I can now pick out the bass pedal hitting the bass drum. Something I had never been able to do before. Incredible separation of all instruments and vocals.
amp: golden tube se-100, 10 mullard el-34 xf4 tubes
pre: conrad johnson pv-10al, 2 tf 12ax7 tubes
cdp: ah 4000, 2 tf e188cc tubes
ic: aq king cobras
sp. wire: romex 10 ga solid core copper
sda ic: stock
test cd: dire straits, bia
volume: 9 o'clock
amp: golden tube se-100, 10 mullard el-34 xf4 tubes
pre: conrad johnson pv-10al, 2 tf 12ax7 tubes
cdp: ah 4000, 2 tf e188cc tubes
ic: aq king cobras
sp. wire: romex 10 ga solid core copper
sda ic: stock
test cd: dire straits, bia
volume: 9 o'clock
Post edited by candyliquor35m on
Comments
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Got cap?~ In search of accurate reproduction of music. Real sound is my reference and while perfection may not be attainable? If I chase it, I might just catch excellence. ~
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Got cap?
That's just what I was thinking Tom. Were those simply stunning, awesome, technology defying capacitators (pun intended) used?Richard? Who's your favorite Little Rascal? Alfalfa? Or is it........................Spanky?.................................Sinner. -
That's just what I was thinking Tom. Were those simply stunning, awesome, technology defying capacitators (pun intended) used?
What's a "capacitator"? Is that anything like a capacitor?
Anyways, I ran a few quick simulations of candyliquor's additional cap on the SDA 2B. What appears to be happening is that the highpass 2nd order filter has it's 40dB/decade slope being increased to 60dB/decade by the addition of the capacitor. The actual crossover frequency is not changing much. There is some peaking near the crossover point.
The end result is that at 100Hz, the filter function has 90dB rejection versus 50dB or so for the high pass section of the original crossover.
Increasing the rejection slope will improve the power handling of the tweeter since it won't have to deal with out-band-power at the same level. Unless the tweeter is made specifically for high excursion and power handling, a lot of tweeters will suffer (sound distorted, strident, strained, or whatever word you want to use.)
Only a few tweeters can deal with BOTH a low crossover frequency (some as low as 1500Hz!) and 1st order highpasses. The EPI/Burhoe inverted dome comes to mind.
So Candyliquors "fix" may not be as far fetched as it sounds. And one shouldn't dismiss it outright. It begs to be looked at more carefully...
Cheers. -
It has been looked at and if you don't mind a 29dB suck out at 3kHz, go for it. :rolleyes:Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
It has been looked at and if you don't mind a 29dB suck out at 3kHz, go for it. :rolleyes:
I looked at one case and that was the SDA 2B. Now I haven't simulated all of candyliquors fixed for the various Polk models he's modified. But the SDA 2B doesn't appear to exhibit a suckout.
Do you have a plot of the SDA 2B with the fix? I have some plots of one of the RTA models with a fix. But the scale is ridiculousy coarse (20dB) steps, so it's hard to conclude anything. -
We've hashed all of this out before. It's a bad idea any way one looks at it.
The fact that you are even considering it along with the fact that you think VCR cables make good interconnects and that a 6 channel Kenwood AVR makes for a good amp has earned you a place on my Bozo List. C ya!Political Correctness'.........defined
"A doctrine fostered by a delusional, illogical minority and rabidly promoted by an unscrupulous mainstream media, which holds forth the proposition that it is entirely possible to pick up a t-u-r-d by the clean end."
President of Club Polk -
We've hashed all of this out before. It's a bad idea any way one looks at it.
The fact that you are even considering it along with the fact that you think VCR cables make good interconnects and that a 6 channel Kenwood AVR makes for a good amp has earned you a place on my Bozo List. C ya!
I'm happy you're resorting to name-calling. It must make you feel superior.
Back to the subject. If the deep suckout (29dB is pretty deep) is happening at 3.0khz it's probably destructive interference at the crossover point. And the phase difference has to be fairly close to 180deg. We could confirm this rather quickly if the original person who ran the test could invert the polarity of the tweeter. The null should be a shallower or possible go the other way and cause minor peaking near the crossover point.
For those who are interested in building their own speaker systems, inverting the tweeter or woofer is a good sanity check for determining if the crossover point is summing correctly. -
Maybe you and CL35M can have dinner sometime.
H9"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 | EE Avant Pre | EE Mini Max Supreme DAC | MIT Shotgun S1 | Pangea AC14SE MKII | Legend L600 | BlueSound Node 3 - Tubes add soul! -
What's a "capacitator"? Is that anything like a capacitor?
It's a play on words....like it said in parentheses. "Pun intended".Richard? Who's your favorite Little Rascal? Alfalfa? Or is it........................Spanky?.................................Sinner. -
Light, delicate and airy. Sounds like your SRS's are some kind of yummy muffins lol. "sorry :-)"
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Aside from the SL1000, the SL2000 is the most shrill tweeter I've heard from this lineup. Are you sure yours are even working? Maybe your poly's or crossover caps are dead?
I still can't get over how smooth the RD0-198 is, and how vast of a difference the 4.1TL upgrade made."He who fights with monsters should look to it that he himself does not become a monster. And when you gaze long into an abyss the abyss also gazes into you." Friedrich Nietzsche -
[QUOTE=I still can't get over how smooth the RD0-198 is, and how vast of a difference the 4.1TL upgrade made.[/QUOTE]
I'll second that.I like speakers that are bigger than a small refrigerator but smaller than a big refrigerator:D -
It's like night and day and the caps are still burning in.
The light and delicate highs are still there but the harsh mids that were being fed to the tweeters are gone forever.
When I tried .47 uf/mfd caps on all 4 tweeters, it removed too much of the mids and I began to lose soundstage and imaging so I changed them to 1.0 uf/mfd caps on the middle 2 tweeters and the soundstage and imaging returned.
These are radial mylar caps which from what I understand are non-polarized. -
Lemme get this straight. You put these caps right at the tweeters, right?
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Funny how the same "chit dont stink members" keep this crap going
even though they have instructed the lower ranks not to
gotta be the PPT
polk power trip -
Lemme get this straight. You put these caps right at the tweeters, right?
yes sir, plug and play
http://www.polkaudio.com/forums/attachment.php?attachmentid=31246 -
candyliquor35m wrote: »It's like night and day and the caps are still burning in.
The light and delicate highs are still there but the harsh mids that were being fed to the tweeters are gone forever.
When I tried .47 uf/mfd caps on all 4 tweeters, it removed too much of the mids and I began to lose soundstage and imaging so I changed them to 1.0 uf/mfd caps on the middle 2 tweeters and the soundstage and imaging returned.
These are radial mylar caps which from what I understand are non-polarized.
Have you tried switching the polarities of your tweeters? The added phase shift from your 18dB/oct tweeter high pass filter may be producing a suckout near the crossover frequency. -
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Have you tried switching the polarities of your tweeters? The added phase shift from your 18dB/oct tweeter high pass filter may be producing a suckout near the crossover frequency.
No but I can do it right now. Would this happen even if the caps aren't polarized? -
candyliquor35m wrote: »No but I can do it right now. Would this happen even if the caps aren't polarized?
Your mylars should be non-polarized, but if you DC reverse bias a polarized cap enough, it will go "poof". Sometimes in a very spectacular fashion.
But I'm not sure what will happen from an audibility perspective if you have low level AC going through a polarized cap. It will probably still work to a certain point. Definitely no-optimal. -
Your mylars should be non-polarized, but if you DC reverse bias a polarized cap enough, it will go "poof". Sometimes in a very spectacular fashion.
But I'm not sure what will happen from an audibility perspective if you have low level AC going through a polarized cap. It will probably still work to a certain point. Definitely no-optimal.
Right now I'm enjoying the music. I'll try to do it later.
Would I hear a difference by just changing 1 tweeter or will I have to do all 4 to hear a difference in that speaker? -
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OK. What does it do for you?
It's changing the crossover point just enough to block the harsh mids that were being fed to the tweeters.
The sl2000 isn't harsh because of the upper frequencies, it becomes harsh when too low of a frequency is fed to it (vocals, snare drum?, etc). You definitely need some of those frequencie fed to it because that's what gives you the wide soundstage.
If I continue to use a smaller and smaller value cap, the cap will block all the mids from getting to the tweeter but I won't have any soundstage left. -
I see.
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I still can't get over how smooth the RD0-198 is, and how vast of a difference the 4.1TL upgrade made.
I'll third that.
The 2B is a fantastic speaker, if you treat it right. Rebuild the XO's, do the TL upgrade, and get the RD-0198.
You don't need to do anything else to the tweeter. Just install the 5.8uf cap on the XO, and it will sound gorgeous.
This debate of the cap inline with the tweeter is really getting old and boring...Good music, a good source, and good power can make SDA's sing. Tubes make them dance. -
candyliquor35m wrote: »Right now I'm enjoying the music. I'll try to do it later.
Would I hear a difference by just changing 1 tweeter or will I have to do all 4 to hear a difference in that speaker?
Candyliquor35,
You really need to do all of them to preserve the correct relative phasing of what Polk calls the "disappearing point source".
If I may make a suggestion for simplifying your mod. If adding the caps is steepening the highpass crossover slope, you can achieve an equivalent result by putting only ONE additional cap right after the first crossover cap instead of having separate caps for each tweeter. This will look like a "T" shaped 3rd order network. You'll need to determine what value that cap needs to be. If you're using 1uF now, try that first.
If the the SDA SRS has biamp terminals, you can easily invert the tweeter array simply by swapping the + and - terminal connections to your amplifier for the tweeter inputs. Or if you only have one amplifier driving these speakers, connect the jumpers black to red for both pairs of terminals, instead of red to red and black to black. This will effectively invert the phase of all the tweeters relative to the woofers without needing to mess with the crossovers. All this is possible because the tweeter and woofer networks have separate grounds.
