CRS+ Just arrived - Need help checking them out.

[TennMan]

I just received a nice pair of CRS+ speakers. They look great. But there is a plastic plug on the back of one of them that is loose. It is just a black push in plug, not an electrical plug. What is it's purpose and what should I do about it being loose? You can see it in the attached photo between the PR and the terminal cup.

I have not made final payment for these speakers so I need to determine if they are in proper operating condition before I do a lot of listening. Any help in doing that would really be appreciated.

Most of all I need help in determining if they are working as they should electronically. I have never heard SDAs so I need to check them for proper operation. Does the battery test work for SDAs with the IC cable connected to check the movement of the MW drivers? Any ideas on how to test SDA speakers for proper operation are welcomed.

They are currently setup with the tweeters 7-/1/2 feet apart. I'm sitting 12 feet away, measured to my ears. Is that setup in the ballpark for a starting point?

The speakers sound good with the IC cable disconnected or connected so I think the tweeters are OK. But I don't hear a difference whether the IC cable is connected or not. I have only listened to Steely Dan Aja for a short time and I realize more setup is probably needed. Could someone recommend a popular CD that really highlights the SDA effect? And describe what I should be hearing?

Thanks in advance!

[Joe08867]

I have never seen any such plug before. Is it a fuse holder of some type?

[Toolfan66]

That is where the SDA cable outlet went on the 1996 CRS+'s they were not part of the binding post cups like the later versions. Clearly Polk was just using up the cabinets they had in stock.. The 96 CRS+ versions also came with a two piece crossover boards..

[quadzilla]

The plug is just for cabinet seal. You can push it back in and it should be fine if it fits fairly tightly.

The sda trouble shooting guide is here http://www.polkaudio.com/forums/atta...9&d=1268334955

That's the info on verifying correct SDA functionality.

[Toolfan66]

Aja is a great CD for the SDA's... Put yourself in a triangle and start from there if the speakers are 8ft apart put yourself about 8-9ft back and go from there. nothing is set in stone but if you start there you will hear a difference with and without the cable..

[gimpod]

Here's a link to the SDA Quick Troubleshooting Information.
SDA Quick Troubleshooting.pdf

That lose plug just glue it back in place. It's not important but does need to be sealed up.
As far as placement go's they should be about 6"-8" off the back wall, about 6' between them with 3' clearance to the outside walls min, no toe-in and on about 28" high stands.

[TennMan]

OK, while checking out the speakers I discovered the IC cable has no continuity between the blades in the plug. I assume there should be? The round pins in the plugs check out fine.

I called Polk and they said the pin/blade cable is no longer available. They do have the blade/blade cable in stock. What do I do now? Can I modify the blade/blade cable to work? Does anyone have an extra pin/blade IC cable?

Thanks

[TennMan]

[QUOTE=Toolfan66;1721999]delete

[nwohlford]

OK, while checking out the speakers I discovered the IC cable has no continuity between the blades in the plug. I assume there should be? The round pins in the plugs check out fine.

I called Polk and they said the pin/blade cable is no longer available. They do have the blade/blade cable in stock. What do I do now? Can I modify the blade/blade cable to work? Does anyone have an extra pin/blade IC cable?

Thanks

Only the pin carries signal in the pin/blade, so you should be fine. The blade is only there for support.

[Toolfan66]

That is where the SDA cable outlet went on the 1996 CRS+'s they were not part of the binding post cups like the later versions. Clearly Polk was just using up the cabinets they had in stock.. The 96 CRS+ versions also came with a two piece crossover boards..

LOL!!!! 1986 not 1996!! The cold medication must have been hitting me hard..

[Toolfan66]

Only the pin carries signal in the pin/blade, so you should be fine. The blade is only there for support.

This^^^^^ Both wires in the cable are soldered to the pin..

[TennMan]

Thanks guys. I guess these speakers have something wrong internally or I have something wrong internally. I've checked everything and still hear no SDA sound on any CD I've tried.

Here is what I've checked so far.

• Checked the speakers with a 1-1/2 volt battery and the MWs move together as expected.
• Checked the speakers out with an ohm meter per the SDA Troubleshooting pdf. The results are below (in red) and seem to be within tolerance.
• Checked to make sure the amp is common ground. It is.
• Checked the speaker wires from amp to speaker for correct polarity.
• Measured and remeasured all the distances for speaker placement and seating

Once I found out the IC cable only had one pin with a wire connected to it, I ran wires from the connectors on each speaker to my chair so I could A-B with the wire connected and without. I can't tell any difference in the sound with the wire connected or disconnected. Could someone tell me what could be wrong? Any help would be appreciated.

[nwohlford]

When the interconnect is connect do both the mids on each speaker move when playing music and without the interconnect does only one mid on each speaker move (only the outer if I remember correctly)?

[TennMan]

When the interconnect is connect do both the mids on each speaker move when playing music and without the interconnect does only one mid on each speaker move (only the outer if I remember correctly)?

The outside Mws do move some but the inside MWs seem to be the only ones that are powered.

[OldmanSRS]

One thing to check is the correct speaker polarity to your common ground amp. Make sure the amp+ is wired to red+ on each speaker and visa versa for the negative. The speakers will play fine but with no SDA if both +/- connections are reversed. It would be worthwhile to run your battery test on the 10's and note which way the cones move related to battery polarity and make sure it's the same on the CRS. This will confirm internal wiring polarity and that the speaker marking for +/- and red/black are correct.

Your pin-blade CRS's will drive both m/w in the same direction with the battery test and play music with/without the IC cable connected.

A dumb thought, but make sure you have the R/L speakers physically postioned R/L.

I make house calls :)

[nwohlford]

The outside Mws do move some but the inside MWs seem to be the only ones that are powered.

I remember wrong the inside ones are the stereo drivers (at least according to the CRS+ manual online). I assume without the interconnect only the inside drivers are moving.

It sounds from your description that the dimensional driver may not be working quite right, but it is hard to judge what moving some means.

As OldmanSRS suggested, I would check the polarity (the links above give a way to check). One of the speakers could even be wired incorrectly.

[TennMan]

Polarity seems to be correct from the AMP to the speakers. I just did the battery test again and it shows the CRS drivers moving the same way as they do on the monitor 10s.

The connectors are pin/blade. I just removed both the MWs from the one speaker and they both are getting power with/without the IC connected.

The left speaker is on the left as viewed from the seated position.

[jtgranby]

If I could read it has already been suggested.



Move your chair up to about 6 feet . You will never hear the SDA effect if you are 14 feet away.


JT

[OldmanSRS]

Remove the speaker wires from the CRS and measure between the negative ends back toward the amp. You should read about 1 ohm. Measure between the positives back toward the amp and verify it reads a few thousand ohms (or open circuit). This confirms a common ground amp and the correct polarity.

[TennMan]

Thanks to everyone who offered help and suggestions for my problem. Special thanks to OldmanSRS who kept pushing me to check and recheck the polarity of the wiring. That is exactly what the problem turned out to be.

[Oldfatdogs]

Is a review on the way Tennman?I curious on the differences between your 10s and crs.Your thoughts please.

[OldmanSRS]

TennMan,
You are welcome. Glad it was a simple fix.

Oldfatdogs, here's my take.
Both are good speakers for their physical size and work well in an average size room. Both are lacking bass below 40 hz and both are a little "boxy" in the 80 - 150 hz range. Both take power well and provide a nice punch.

The imaging on the CRS's is well, SDA, which puts mono signals nailed to the center of the sound-stage and stereo signals spread out well beyond the outside edges of the speakers. Out of phase signals come from behind or 90* to the sides. There are many spatial queues and instruments are well defined in space. The SL2000's are a little laser-like especially for saxophone. For my ears, the sweet spot is 1.5 times the distance between the speakers. Closer provides a sense you on-stage with a less well defined center and further is like sitting further back from the stage.

The 10's, especially with the peerless drivers are smooth in the top end and work very well for most recording especially jazz. The 10's dig a little deeper than the CRS but not that much. The sound-stage is pretty much confined to between the speakers with only the out of phase signals extending outward to what sounds like inside you head. The sweet spot is not as critical as with the CRS's. Any place reasonably between them even with them toed-in works well. The 10's work very well for a one room party.

Both speakers are good for what they are and both are different for the same reason. If I had to give up one, I would keep the CRS's and add a high quality sub (which I use). The setup makes a fine compact system.

[thsmith]

Thanks to everyone who offered help and suggestions for my problem. Special thanks to OldmanSRS who kept pushing me to check and recheck the polarity of the wiring. That is exactly what the problem turned out to be.

WHat exactly was the problem?

Did you have a phase inverting preamp that required you to reverse positive and negative at the speaker ?

[Oldfatdogs]

Thanks OldmanSRS,well put I have the 10s with peerless and 7bs.I have never heard the sda speakers I always think OK what am I missing.I do plan on getting a set when a nice pair come up local to me at a good price.Thanks again Dan

[TennMan]

Below is my first impressions of how my 10Bs compare to my newly acquired SDA CRS+ speakers. Thankfully OldmanSRS has already said a lot of what I was going to say. What he had to say was right on target and he left me with a good foundation for what I have to say about the differences I find between these two speakers. When you read this keep in mind that I'm a newbie to SDAs and my CRS+ are the only SDA speakers I have ever heard. I may be completely off base in describing SDAs in general. This is just my feelings about my new pair of speakers... nothing else. I apologize for this ending up being so long.

I listened to my CRS very little with the SL2000 tweeters installed before I swapped them out with the RDO-194s from my 10Bs. The SL2000 tweeters installed from the factory in the CRS have a very similar sound to SL2000s that come in 10Bs so I already knew I preferred the sound of the 194s.

Without the IC cable hooked up I find my 10Bs and the CRS to sound very similar in the high and mid range. To me the 10s have a fuller sounding bass compared to the CRS+. I've had my 10s a little over a year and never felt a need for more bass, even though I'm sure OldmanSRS is correct when he says they are lacking below 40hz. I sort of expected less bass from the CRS because of the smaller cabinet size. The CRS speakers seem to have a more defined and tighter bass compared to the 10Bs but they leave me feeling like I need to add a little EQ to get me back to the bass I'm use to with my 10s. I prefer the low end of the 10s. I will probably be adding a sub soon.

With the IC cable hooked up the CRS+ adds a whole new dimension to the sound. It's like going from standard TV to HD. I won't say the difference is as dramatic as going from high definition TV to 3D TV but it's close. I reeeeally like it. OldmanSRS did a good job of describing how the SDA changes the sound so I won't try to cover that again. Even with the IC cable hooked up I still feel I need more bass but the tradeoff of bass for the SDA sound is a good one since a sub should easily fix that. Or... maybe a pair of 2Bs would be a better fix.

I'm not quite there yet with my setup, which is still exactly what it was with the 10Bs. The CRS cabinets are 6 feet apart. There is about 7-1/2 feet between the tweeters. I'm sitting back from them about 12-1/2 feet (measured to my ears). That puts me out of the ideal range for the sweet spot. However, with that setup what I hear is still very pleasing and gives a wide and airy feeling to the music. The speakers seem to disappear and are no longer the limiting factor in where the sound of instruments originates. Vocals seem to come from more focused locations. I don't get the full 90* wrap around effect like OldmanSRS describes. My room is 20 feet wide and when listening to the 10s my sound stage is just to the outside edge of the speakers, or about 10 feet wide, with some of the highs occasionally extending a few feet more outside of that. With the CRS the sound seems to fill the front half of the room and sometimes extends beyond the walls. I'm not getting the 90* wraparound effect. I'm getting probably a 45* degree wrap around and I'm very happy with it for now. Keep in mind I have never heard SDA speakers before.

Well, there you have my impressions of my 10Bs in comparison to my CRS+. I's about the best I could do with my limited audio vocabulary and the limited amount of time I've had to listen to the CRS+ speakers.

[TennMan]

WHat exactly was the problem?

Did you have a phase inverting preamp that required you to reverse positive and negative at the speaker ?

The previous owner had installed a new replacement driver and had the wires going to it reversed. A small mistake that made a big difference in the sound. That could have possibly been the reason he sold them.

[Oldfatdogs]

Nice write up Tennman, enjoy your new speakers. Dan

[nwohlford]

I am glad you got it figured out. Enjoy the CRS+s; they are a great speaker.

[OldmanSRS]

TennMan,
Great write up. Just to clarify what I said about the wrap-around, it's highly program dependent. The more L-R difference signal present, the greater the sound stage width expansion. The more out of phase signal present, the further back (like surround) the sound stage expands. The interesting thing about the way SDA reproduces the out of phase signals compared to non SDA is in non SDA OOP signals seem to converge in your head. With SDA, there is a better sense of the sound coming from behind you.

What you said about the bass is true as well and the SCRs have less of a boxy sound but also less perception of low-mid bass. They sound a little more accurate but for jazz with a stand up bass, the 10's do better IMO. Thats where a good sub comes in with either and especially with the CRS. There's a lot of tactil stuff going on from 18 - 30hz in many recordings that the smaller speakers can't reproduce with authority.