SDA CRS Help
ptrask
Posts: 12
I recently picked up a pair of SDA CRS speakers for $50.00. They appear to be the original series, with the single tweeter. The previous owner had replaced one of the 6.5 inch drivers in each speaker with a Radio Shack generic woofer. 
There is also no interconnect cable with the speakers. I have a few questions.
1) I have a pair of Polk RTA 8 towers with cabinets that are pretty beat up but still sound great. Can I pull the drivers from the 8s, and replace them in pairs in my SDA CRS speakers?
2) Are these 4 Ohm or 8 Ohm speakers? My (old) multi-meter only has a 1000K setting, and won't read the impedance - just that there is continuity. My receiver would like to know the impedance!
3) I want to build my own interconnect cable. I figured I would replace the two-blade jacks on the back of the speakers with either a 1/4 inch phono jack, or banana-plug terminals. Does the original interconnect cable connect terminal A to A and B to B, or does it "cross" A to B and B to A? Does the interconnect cable have to be a specific length? A guy at a local vintage audio repair center thought the cable needed to be 19 feet long, but he wasn't sure.
My current systems are a pair of Polk RTA 11t towers (1992) driven by a Carver MXR-150 Receiver, and a pair of Polk RTA 12 speakers (1986?) driven by a 1976 Akai AA-1050 Receiver for playing my records. Not as "present" as the 11s, but a much more "vintage" sound that complements the turntable. I'm planning on using the SDA CRS speakers with either a Pioneer SA-737 or my original receiver that I bought new in 1982 at Tweeter, Etc. It is a Denon DRA-400, putting out 40 wpc with plenty of headroom. I have been using the Denon with a pair of Polk Monitor 5s speakers for the past 35 years, and they sound great. I generally don't crank that system the way I do the others, so I figured the SDAs would give me better imaging at normal listening levels than the 5s.
There is also no interconnect cable with the speakers. I have a few questions.1) I have a pair of Polk RTA 8 towers with cabinets that are pretty beat up but still sound great. Can I pull the drivers from the 8s, and replace them in pairs in my SDA CRS speakers?
2) Are these 4 Ohm or 8 Ohm speakers? My (old) multi-meter only has a 1000K setting, and won't read the impedance - just that there is continuity. My receiver would like to know the impedance!
3) I want to build my own interconnect cable. I figured I would replace the two-blade jacks on the back of the speakers with either a 1/4 inch phono jack, or banana-plug terminals. Does the original interconnect cable connect terminal A to A and B to B, or does it "cross" A to B and B to A? Does the interconnect cable have to be a specific length? A guy at a local vintage audio repair center thought the cable needed to be 19 feet long, but he wasn't sure.
My current systems are a pair of Polk RTA 11t towers (1992) driven by a Carver MXR-150 Receiver, and a pair of Polk RTA 12 speakers (1986?) driven by a 1976 Akai AA-1050 Receiver for playing my records. Not as "present" as the 11s, but a much more "vintage" sound that complements the turntable. I'm planning on using the SDA CRS speakers with either a Pioneer SA-737 or my original receiver that I bought new in 1982 at Tweeter, Etc. It is a Denon DRA-400, putting out 40 wpc with plenty of headroom. I have been using the Denon with a pair of Polk Monitor 5s speakers for the past 35 years, and they sound great. I generally don't crank that system the way I do the others, so I figured the SDAs would give me better imaging at normal listening levels than the 5s.
Comments
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First, yours are CRS+, the earlier variants had 2 tweets.
1: no, the MW models are different between the two. You want mw6510s in all positions. Iirc, they can still be had through Polk as new.
2: 6? with the ability to dip lower
3: A-A, B-B.
Rock that Denon. -
First, yours are CRS+, the earlier variants had 2 tweets.
1: no, the MW models are different between the two. You want mw6510s in all positions. Iirc, they can still be had through Polk as new.
2: 6? with the ability to dip lower
3: A-A, B-B.
Rock that Denon.
6510 and 6511 for the dimensional (driver on the right of the speaker baffle).
I believe that the 6511 is available from Polk too.Just a dude doing dude-ly things
"Temptation is the manifestation of desire which equals necessity." - Mikey081057
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6510 and 6511 for the dimensional (driver on the right of the speaker baffle).
I believe that the 6511 is available from Polk too.
No, the blade/blade CRS+ uses all 6510's.3) I want to build my own interconnect cable. I figured I would replace the two-blade jacks on the back of the speakers with either a 1/4 inch phono jack, or banana-plug terminals. Does the original interconnect cable connect terminal A to A and B to B, or does it "cross" A to B and B to A? Does the interconnect cable have to be a specific length? A guy at a local vintage audio repair center thought the cable needed to be 19 feet long, but he wasn't sure.
Poor connector choices, use 4 pole Neutrik SpeakOn connectors. A search here will show you what they are and which ones to buy. Use high quality speaker cable for your SDA cable. That does not mean 16 gauge zip cord. The SDA cable can be any length.
I'm sorry, but none of your power sources will come close to properly driving those speakers. Yes, you will get sound, but it won't be close to what they are capable of. BTW, high powered amps are not only about playing loud. They are more about producing a nice full sound at lower levels.
Seriously consider replacing those nasty SL2000 tweeters with the RD0194 available from Polk.
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 -
6510 and 6511 for the dimensional (driver on the right of the speaker baffle).
I believe that the 6511 is available from Polk too.
No, the blade/blade CRS+ uses all 6510's.3) I want to build my own interconnect cable. I figured I would replace the two-blade jacks on the back of the speakers with either a 1/4 inch phono jack, or banana-plug terminals. Does the original interconnect cable connect terminal A to A and B to B, or does it "cross" A to B and B to A? Does the interconnect cable have to be a specific length? A guy at a local vintage audio repair center thought the cable needed to be 19 feet long, but he wasn't sure.
Poor connector choices, use 4 pole Neutrik SpeakOn connectors. A search here will show you what they are and which ones to buy. Use high quality speaker cable for your SDA cable. That does not mean 16 gauge zip cord. The SDA cable can be any length.
I'm sorry, but none of your power sources will come close to properly driving those speakers. Yes, you will get sound, but it won't be close to what they are capable of. BTW, high powered amps are not only about playing loud. They are more about producing a nice full sound at lower levels.
Seriously consider replacing those nasty SL2000 tweeters with the RD0194 available from Polk.
Overlooked the third paragraph, my apologies!Just a dude doing dude-ly things
"Temptation is the manifestation of desire which equals necessity." - Mikey081057
" I have always had a champange taste with a beer budget" - Rick88
"Just because the thread is getting views don't mean much .. I like a good train wreck doesn't mean i want to be in one..." - pitdogg2
"Those that don't know, don't know that they don't know." - heiney9
"Audiophiles are the male equivalent of cat ladies." - Audiokarma Member -
No need for that.
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 am fully aware of the advantages of high powered receivers. This system is set up in my bedroom, where I mainly listen to classical music using an old Technics turntable. I think the CRS speakers will be fine with a lower powered amp driving them. I have a number of higher powered options, but don’t expect that they will be needed with what I intend here. I’m more interested in getting the imaging right.
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I work on a little of everything - when I have time. However, I am not Canadian. That is a picture from the front deck of our vacation house on Prince Edward Island.
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I am fully aware of the advantages of high powered receivers
There are no advantages to any receiver.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 -
Okay - I've been searching online, and everywhere I look it says that the MW 6510 is discontinued, and that the recommended replacement is the MW 6503. Any thoughts?
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Call PolkPolitical 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 -
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1 800 377 7655. polk customer service.
Monitor 4.6, 5jr, 5, 7, 10, 11. RTA 8TL. RTA 11T. SDA 2B. -
1 800 377 7655. polk customer service.
Monitor 4.6, 5jr, 5, 7, 10, 11. RTA 8TL. RTA 11T. SDA 2B. -
Anybody know the specs on the CRS+ speakers? Wondering if they’re efficient enough to drive them with a tube amp ~25 watts per side.
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6 ohm nominal, 90dB efficiency. Your amp will drive them, but not sufficient to drive them properly.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 -
Thanks. I’ve been driving them with a Carver amp/preamp, and I can only say that it sounds a little “metallic” particularly on classical music. Thought a tube amp would “warm them up”.
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For sure, a tube amp with more power will do them justice.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 about the specs on a pair of RTA 12 speakers? Original series.
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For sure, a tube amp with more power will do them justice.
I've settled on a vintage Adcom GFA-555 Flat Front amplifier with a PS Audio preamplifier to drive these speakers. Probably a little overkill for my little listening space, but that's what I have. I pulled the drivers from these as a last check prior to moving to the new system, and found that each speaker has one MW-6510, and one MW-6503. Although everything I have read shows that the 6503 is a direct replacement for the 6510, am I likely to notice a difference keeping that rather than going to four matched drivers? -
The Adcom GFA-555 isn't overkill. I have one and I have a set of CRS+ speakers. An amp isn't just about how loud it can play your speakers, an amp with plenty of power can control the drivers better for a cleaner sound and more dynamic range. Dynamic range is really important if you are going to use your CRS+ for watching movies. A smaller amp might have done the job but a larger amp can do it just as well or better.
- SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
- Crossover upgrades by westmassguy
- Marantz 1504 AVR (front speaker pre-outs to Adcom 555)
- Adcom GFA-555 amp · Upgrades & speaker protection added by OldmanSRS
- Pioneer DV-610AV DVD/CD player
- SDA CRS+ · Hidden away in the closet
- SDA 2BTL · Sonicaps · Mills resistors · RDO-198s · New gaskets · H-nuts · Erse inductors · BH5 · Dynamat
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I wasn’t saying it was overkill based on the volume it will generate, just based on the fact that my listening room is small - about 9’ x 11’. Seems like a little much to have an amp rated at 250 per side , and tested to 290 per side for that small area. Prior to the Adcom, I was driving the speakers with a Carver MXR-150. Prior to that, I was using a NAD rated at 40 per side, and I honestly don’t hear a difference. Of course, I suffer from low-tone deafness, due to too many concerts and loud stereo systems over the years, so maybe someone else would hear a difference. On this system, I’m listening to records 90% of the time, and those are a mix of classic rock, and classical.
