Has anyone tried this before - SDA CRS+10?

TennMan

I've listened to my CRS+10s a lot more tonight. I'm extremely happy with how they sound. To me the sound is a blend of the things I like best about the monitor 10s and the CRS+ speakers. I have a wide SDA sound and enough bass to make me happy. Exactly what I was hoping for. I have put the monitor 10 drivers in the CRS cabinets and put them in the back of the closet for safe keeping. I have no intention of going back to them.

I don't have a way of measuring the response curve of the speakers. I doubt it would be as good as the standard models that Polk produced but that's OK. They make me grin from ear to ear when I'm listening to them and that was the result of this project I was looking for. I encourage anyone who owns a pair of 10Bs and a pair of CRS+ speakers to give this a try. It's easy to do, can be easily reversed and you might like it!

F1nut

Or just buy a pair of 2B's and call it a day.

TNHNDYMAN

TennMan-

I've enjoyed reading about your little conversion. Glad you are enjoying it. Since they sound better upright on the floor why don't you sell me your nice stands for my 10's :cheesygrin: If you don't care PM your info on location and ph # if you don't mind. I'm planning a trip down to ScottyBoy's again around early March to pick up some gear I bought from him and if we can work it out, I'd love to listen to your new setup.

TennMan

I wasn't clear about the stands. They are still being used. They have a 4, or 6 degree (I can't remember which) angle on the surface where the speaker sits to tilt the speakers back slightly. I just had to adjust them a little so they don't tilt the CRS+10Bs back any. The SDA effect seems to be better with the speakers sitting up straight instead of tilted back.

PM sent

OldmanSRS

TennMan,
You met your goal. You have the SDA cancellation of the CRS with the tonal quality of the 10's. Your trade off is a slight phase error with the arrival of the SDA. For example, your right ear will hear the left stereo signal and the right SDA signal but the right SDA signal will arrive earlier in relation to the left channel stereo signal by about 0.0003 seconds because the spacing between the right SDA and right SA is narrowed by about 3" less distance than in the CRS. This applies to the opposite speaker as well. Can you hear the 0.0003 second timing difference? I doubt it.

TennMan

Wouldn't the timing with my CRS+10Bs be the same as it would with 2Bs since their spacing appears to be the same as the 10s? We should get together sometime and compare your CRS+ with my CRS+10Bs. I would like to hear your impression of them. Have you considered doing the swap yourself?

OldmanSRS

Edit: See next post.


We can meet up sometime. I will PM you soon about that.

OldmanSRS

1.2 and CRS spacing.


10A spacing.



Wouldn't the timing with my CRS+10Bs be the same as it would with 2Bs since their spacing appears to be the same as the 10s?

Hard to say. It's not the same theoretical ideal distance (the human head between the ears width) as the CRS but the question is, did Polk compensate for narrower distance in the 2Bs with a phase shift in the XO?

And more importantly can you tell? Think not.....

xschop

Tennman, are you still running these hybrids?

What is the tweeter center distance from the stereo MW on the 10's?

I'm finding better sound with the tweeters moved closer to stereo MWs. The SDA MW to stereo MW distance is almost indistinguishable whether 3" apart or right next to each other.

TennMan

I no longer have the 10Bs. I sold them when I got my 2Bs.

nspindel

nspindel wrote: »

Just chiming in with an opinion here. I used to own a pair of CRS+'s. The only mod I ever did to them was to swap out the SL2000's for 194's. I then sold those speakers when I grabbed a pair of 2B's, and then sold the 2B's when I moved to 1C's. But I owned the CRS+'s from 1989 until 2005, so I've had 16 years of experience with them. The CRS+ is an incredible pair of speakers, undoubtedly the best bang for the buck in the SDA family (well, in terms of original retail prices). Don't let their size fool you.

About a year ago I grabbed another pair of CRS+'s from Sal that I plan on doing every mod under the sun to. My wife and I will be selling our house in a couple of years and downsizing substantially, so I will be going back to the CRS+'s as my main speakers, and the 1C's will become the property of some lucky Polkie in the NYC area. I plan on doing my CRS+'s up right - veneer, rings, dynamat, armacell, sonicaps, Tony's boards, TL-mod/198's, Cardas posts, Dreadnaught, the works. This is a speaker so worthy of the best treatment possible. They pack an incredible punch. Once I get them done, they will be my speakers for life.

If you're not over-the-moon thrilled with the CRS+'s, then it's got to be an issue with your setup, and I don't think building a Franken Polk is going to sort you out. Figure out how to get the CRS+ to sound optimal, and you'll be more than happy.

Waking up this thread made me wonder what I had said here in the first place, so I looked back to the beginning and found this. I seriously think this might be some of the best advice I've ever tried to offer on this forum. It's pretty cool reading this post of mine five years later, having done everything that I said I'd be doing. I did sell my house, I did tremendously downsize, and I did take those CRS+'s from @Lasareath and did every mod I mentioned.

I've personally never understood the calling to turn M10's into Franken-SDAs. Why not just find a pair of 2B's and have a properly voiced cabinet and PR?

TennMan

nspindel wrote: »

I've personally never understood the calling to turn M10's into Franken-SDAs. Why not just find a pair of 2B's and have a properly voiced cabinet and PR?

I had a pair of 10Bs. I still have a pair of CRS+ and I now listen to TL2Bs. If I didn't have the 2Bs I would be making plans to build a pair of SDA-TL10Bs. I consoder them to be the speaker between the CRS+ and the 2Bs that Polk could have built. It's one of those things that you just have to try it to see if you like it. I could go into all the reasons why that combination works but why? I've done it a couple of times before but not many people seem to get it.

TennMan

To clarify my lat post... what I meant to say is if I couldn't find a pair of 2Bs I would prefer a pair of SDA-10Bs over my CRS+. I love my TL2Bs.

nspindel

But 2B's are out there to be found. Why not find a pair instead of inventing your own product?

TennMan

nspindel wrote: »

But 2B's are out there to be found. Why not find a pair instead of inventing your own product?

Some people who what to go fast simply go out and buy a Corvette. Other people who want to go fast put a Corvette engine in a Camaro. Both arrive at their destinations quickly but the guy with the Camaro gets that satisfaction of having a car that is a little different. The guy with the Camaro didn't invent anything. He just took some of Chevy's best parts and assembled them in a way that produced really good performance.

FestYboy

Some people who want to go fast simply go out and buy a Corvette. Other people who want to go fast put a Corvette engine in a Camaro. Both arrive at their destinations quickly but the guy with the Camaro gets that satisfaction of having a car that is a little different. The guy with the Camaro didn't invent anything. He just took some of Chevy's best parts and assembled them in a way that produced really good performance.

And then there are those who want to beat the pants off of both of them with their own game and put the LS engine in a Mazda (rx-7, or Miata).

xschop

Great analogy Tenn. Some folks like the best of various designs amalgamated into one hybrid that does it all. Toyota V12 mated to Vette transaxle grafted into a GT Porsche comes to mind.
That said until you've driven the hybrid, don't knock it. I imagine those CRS+10s sounded excellent. I would love to hear the bass extension on a set one day. I know the highs would shine and be less airy than factory CRS seeing the tweet is closer to stereo MW.

nspindel

Tell me what this "best of various designs amalgamated into one hybrid that does it all" approach actually gives you? In what way is your "CRS+10" any better than a 2B? What sacrifice is being made with the 2B that is solved with the tricked out monitors?

xschop

Im Tenn's case it gave him a smaller foot print, he had everything already on hand, better bass response to his liking, and arguably better detail of the highs.
And lastly, he followed the advice of Mr Polk and experimented.

TennMan

xschop wrote: »

Im Tenn's case it gave him a smaller foot print, he had everything already on hand, better bass response to his liking, and arguably better detail of the highs.
And lastly, he followed the advice of Mr Polk and experimented.

You hit the nail on the head xschop!

I don't believe I've ever said the CRS+10Bs are better than the 2Bs. I don't think they are. If I did I wouldn't have my 2Bs. The 2Bs aren't huge but they are the largest SDA speaker I can get in my room as you can see in the photo below. The 10Bs were actually a better fit.

I have only stated that I prefer the sound of 10Bs that have been converted to SDAs with CRS+ parts over the sound of my CRS+. Everyone might not feel that way if they heard them. I think the reason I prefer them is because of the passive being located on the front and the larger cabinet volume. As cabinet volume increases the lower bass should follow with everything else being equal. The 10B passive is retained in the swap so it is tuned for the 10B cabinet.

I may have to downsize someday. If I do the CRS+10Bs will be my first choice but I have saved my CRS+ just in case that didn't work out. As you can see in the photos below the 10Bs don't take up a lot more room than CRS+ if you use stands to bring them both up to ear level.

I'm not promoting the SDA 10Bs over the CRS+ The CRS+ is a great speaker. I'm just saying if you have a pair of CRS+ (like I did) and a pair of 10Bs what would it hurt to give it a try. The only modification you have to make is to drill one hole inside he cabinet. It's not like you have to chop up the speakers and ruin them. Who knows? You might like what you hear.

nspindel

To each his own, I guess. But I'm the type who doesn't wander far from the reservation.

Toolfan66

5 yrs old already??

Dennis Gardner

I bet you do have nice SDA sound in that room, TennMan! I rarely see wall spaces on both sides of a set of SDAs so open.

TennMan

Dennis Gardner wrote: »

I bet you do have nice SDA sound in that room, TennMan! I rarely see wall spaces on both sides of a set of SDAs so open.

It's pretty good room. If my wife would let me add room treatments it would be great. It is a little too reflective with all the hard surfaces.

When I had the house built I changed the plans so the fireplace would be dead center in the room so speakers and sofa would be centered in the room. The openings you on each side of the speakers go into a large foyer behind the fireplace. The openings are the same on each side of the room so the distance to the walls is identical. I like things to be symmetrical.

voltz

I put my CRS+'s crossovers in my M10's after Reading what Ronnie had done. I use my Binding post cup so I could use my DreadNaught and thought it was kind of cool to listen to it that way

I have since gave my Monitor 10's to a friend at Work who was getting ready to retire and and it has the upgrade M10 crossover back in it, and i did some special work with blackhole 5 that Dave @westmassguy told me about and Jerry is on cloud 9 listening to the 10's. they also have the RDO-198's in them.

his system is the M10's + Peachtree Integrated amplifier and Marantz CD player.

But thanks to Ronnie I had a lot of fun with my M10 SDA's

Dennis Gardner

SDAs like symmetry for sure, even if it is walls that are too close, they need to be the same distance so that they are bad on both sides the same!

xschop

Bump for @kcoc321

kcoc321

Thx xchop for the link and thank you Tennman for the tenacity to stand by your convictions.

Toolfan66

Holy Cra.p where did the time go??