another new guy with SDA 2B's
littlewoodboats
Posts: 823
I caught a set on epray that were local delivery only but inside 150 miles.
I talked with the seller and we made a deal to meet half way if I won the speakers. I opened the bid at $99.00 and was the only bidder.
The guy met half way for the price of breakfast and a bloody mary. Totally cool guy works for NASA
I got them home and drove with a Yamaha CR-840 that had driven home theater speakers to great effect.
All is well until I put the SDA cable in place and the receiver smoked.
The receiver was not healthy but worked. I am currently running a Yamaha CA-1000 with the A/AB switch welded to A position through missuse
At 17 watts class a the Best of the Guess Who sounds awesome
I talked with the seller and we made a deal to meet half way if I won the speakers. I opened the bid at $99.00 and was the only bidder.
The guy met half way for the price of breakfast and a bloody mary. Totally cool guy works for NASA
I got them home and drove with a Yamaha CR-840 that had driven home theater speakers to great effect.
All is well until I put the SDA cable in place and the receiver smoked.
The receiver was not healthy but worked. I am currently running a Yamaha CA-1000 with the A/AB switch welded to A position through missuse
At 17 watts class a the Best of the Guess Who sounds awesome
Post edited by littlewoodboats on
Comments
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Congrats on your new to you SDA's, tons of info on this forum from knowledgeable folk.Monitor 7C's With Tubes
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littlewoodboats wrote: »I caught a set on epray that were local delivery only but inside 150 miles.
I talked with the seller and we made a deal to meet half way if I won the speakers. I opened the bid at $99.00 and was the only bidder.
The guy met half way for the price of breakfast and a bloody mary. Totally cool guy works for NASA
I got them home and drove with a Yamaha CR-840 that had driven home theater speakers to great effect.
All is well until I put the SDA cable in place and the receiver smoked.
The receiver was not healthy but worked. I am currently running a Yamaha CA-1000 with the A/AB switch welded to A position through missuse
At 17 watts class a the Best of the Guess Who sounds awesome
you need to make sure the receiver is a common ground design. Most older gear was NEVER made to drive 4ohm load, so you may have 2 strikes against you... non common ground and 4ohm = POOF
Polk put that warning label on there for a reason.
You have some nice speakers now you need an amp to run them most any receivers will never do them justice and you'll just end up frying tweeters or other gear -
you need to make sure the receiver is a common ground design. Most older gear was NEVER made to drive 4ohm load, so you may have 2 strikes against you... non common ground and 4ohm = POOF
Polk put that warning label on there for a reason.
You have some nice speakers now you need an amp to run them most any receivers will never do them justice and you'll just end up frying tweeters or other gear
Correct on every point. The receiver was common ground but not healthy.
The frying of the Yamaha put the stuck Ca-1000 back in service. I am having a Yamaha CR-2020 restored/upgraded and plan to drive these for my office system.
I understand what you are saying but do not necessarily agree. -
you need to make sure the receiver is a common ground design. Most older gear was NEVER made to drive 4ohm load, so you may have 2 strikes against you... non common ground and 4ohm = POOF
Polk put that warning label on there for a reason.
The 2B's are 6 ohms.now you need an amp to run them most any receivers will never do them justice and you'll just end up frying tweeters or other gear
AGREED!!!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 -
I have read all over that the 2Bs are 6 ohm, but when I measured mine, they showed 3.7 ohms by themselves, and 3.4 when the interconnect cable was attached.-SPINNER-
SDA-2b
Adcom GFA 555
Marantz SR880
JBL CF120
Onkyo TX-SV727
Other Junk -
Well, there IS a difference between DC resistance and nominal AC impedance over a range of 20-20K Hz.
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TheRealSpinner wrote: »I have read all over that the 2Bs are 6 ohm, but when I measured mine, they showed 3.7 ohms by themselves, and 3.4 when the interconnect cable was attached.
As bmbguy stated, you are measuring resistance, not impedance.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 -
One thing I did not check was resistance. I did verify that everything should be good to go at 6 ohms but did not check that older speakers were still at the design value. I can see how it could change over time as components age.
Check this across the binding posts? If I find the proper value is this a sign of general health?
They are leaking a bit of air. I did the leak check and while everything moves the mids fall right back down to level. I am used to using Moretite and have the dynamat extreme. I went into the Navy in 1980 so have not done real stereo in decades but remember well the first thing we did to a sealed cabinet speaker was the Moretite for a good cabinet seal. It also works great inside a hollow base turntable.
I understand what has been said regarding separates and would go that route if these were going in my house instead of the office. The CR-2020 I plan to use is rated for a four ohm load so that should not be an issue. I sent an e-mail to the tech rebuilding the unit but have not heard back as of yet. Definitely something to keep in mind.
Thank you for all of your input.
Oops. I guess F1nut was posting as I was. Is there a way to test the cabinets for proper value? -
As bmbguy stated, you are measuring resistance, not impedance.
To the OP,
Impedance varies with frequency so unless you are measuring it while playing music you aren't getting the correct outcome. Everyone is correct when they say 6 ohm nominal. Which means they could be as low as 3 ohms or as high 20 ohms depending on the frequency played.
You are measuring resistance when you put a DMM at the input terminals of the speakers."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! -
I did verify that everything should be good to go at 6 ohms but did not check that older speakers were still at the design value. I can see how it could change over time as components age.
How did you test for the nominal impedance?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 -
How did you test for the nominal impedance?
I was referring to the amplifier section being good to go at 6 ohms.
