Khancenter or RS wmtw center

[mikey15]

I think I'm going to build some Khans. My question is will the RS wmtw be a better center match because it uses the same drivers as the Khans or will it be hard to hear a difference between the RS180 vs the RS225. Size is not an issue
Thanks
Mike

[joeybutts]

Go big or go home.

Supposedly you will be satisifed with the Khancenter, but I figure if you have the power, and the drivers, go with the RS center. I have the same plans, which should be starting here in a week or two.

[mikey15]

I wonder if the xo is going to change with the un shielded drivers. I think I'm with you it is going to be the RS center. Which XO are you going to use for the RS center. I'm thinking CJD because he designed the Khans.

[joeybutts]

That was exactly my thoughts...

[---k---]

First problem is going to be finding the drivers. It appears that PE has decided to discontinue the shielded 8 ohm drivers used in all of these designs. The replacement drivers are close. Curt has decided that the RS180 and RS225 are close enough to be used as the woofers in the Statements. I have some concerns about the Khans, since we're using the RS drivers in both the mid and woofer position.

Here is an exchange I had with CJD:

"Ryan" wrote: >Have you taken a look yet at the new RS150-8 yet to decide if they are close >enough to the old? Or are the Khans dead?

"CJD" wrote:

I've looked but honestly have no idea on compatibility yet. Same problem for the 225 and all the rest. Not sure the best answer yet though redoing the mtm is cheaper than the 3 way designs as far as a live test goes.

I've read many forum posts where people exchange drivers randomly and are very impressed with the results. So, maybe swapping the drivers would be good enough for many. But, it may not meet CJD's perfectionist standards.

Someone should buy and ship him a set of drivers for testing.

[BOBinGA]

From a quick look through the crossovers for each, the Khancenters look like the best match. They use the same basic crossover slopes and the drivers are in the same polarity as the Khans. All the variations of the RS WT/MW design have different polarities and would sound out of phase with the mains.

The new RS unshielded drivers look like they are simply the old drivers with the shielding cup and bucking magnet removed. It doesn't look like the driver suspension, cone or voice coil has changed. (I haven't measured them yet, so I could certainly be wrong, but the new specs indicate that only thing that's changed is the magnets.) You might have to change the size of the boxes slightly to account for the new T/S paramters, but the crossovers shouldn't have to change since the same suspension should have the same frequency response in their usable bandwidth, the impedance hasn't changed and there is only a very slight change in efficiency, if any, due to the magnet change. But obviously, only remeasuring the drivers will tell for sure.

-Bob

[cjd]

I did a crossover for the larger RS WT/MW center that should be a pretty good match for the Khans. But I thought this used the shielded tweeter, which was NOT a direct swap, in my experience, for the un-shielded tweeter - at least, not in all designs.

I know simply pulling the bucking magnet results in less than optimal changes, so hopefully these aren't *just* that. Everything points to them being drop-in swaps, but I'm always so hesitant to just make a blanket claim of that sort. With Curt also thinking this, it's probably safe.

Mean time, I'm seeing what I can do to get my hands on some to at least try in the MTM, and go from there. A MKII of the big towers is quite temping, I must say... Get a couple features into the mix I shoulda done in the first place.

C

[BOBinGA]

Sorry, I wasn't thinking about the tweeter. Those are different since the shielding cup is an enclosure and would definitely affect its low end and require some adjustment.

-Bob

[joeybutts]

But I thought this used the shielded tweeter, which was NOT a direct swap, in my experience, for the un-shielded tweeter - at least, not in all designs.

C

Pretty sure the RS center uses the unshielded RS28A.....Someone please double check and clarify! Tanks.

Miscelaneous discussion common to both



Shielded vs Unshielded drivers

The drivers used for both the center and towers are the same, and are listed in the first post. The RS28A tweeter needs to be UNSHIELDED, but the mid and woofer are SHIELDED. Discussion:

[---k---]

But I thought this used the shielded tweeter, which was NOT a direct swap, in my experience, for the un-shielded tweeter - at least, not in all designs.
C

I spent 5 minutes in that the original thread. I saw no reference to the shielded tweeter. I think you may be getting your designs mixed up.