RS28 + RS52 + 2x RS225 TMWW question

**---k---** · 27 April 2015, 13:01 Monday

You might have missed Jon's Modula Neo CC:

HTGuide Forum

http://www.htguide.com/forum/showthread.php?27218-Modula-NeoD-CC-Introduction-and-Build-Thread

It is a WTMW with the RS52 and and option for the RS180. Just might give you some insight into using the RS52.

**JeanM** · 28 April 2015, 02:23 Tuesday

Thanks Ryan!

**JeanM** · 29 April 2015, 12:50 Wednesday

Does anybody have the BoxSim (.BCH) files or .frd freq. response files for the RS52 driver that I can import into BoxSim so I can simulate a crossover ?

I found RS28 and RS225 here - http://www.rjbaudio.com/Audiofiles/D...D%20files.html

Called Madisound and they wouldn't design a crossover using their Leap service since they don't sell these drivers.
Called PE and they only over xover pro designs but it doesn't take into account driver measurements I guess.

Thanks much!

**JeanM** · 04 May 2015, 14:29 Monday

Small update.

- Picked up 36" by 9.25" baffle to temporarily mount the drivers to play with, I'll most likely go with a taller baffle.
- Currently in a sitting position on the couch the tweeters are almost ear level, vs my finished towers.
- I've been basically looking at all the various projects that I can find using these drivers to analyze their crossovers
- Interesting how much bass you can get with room placement and also playing with side panels of various sizes and their positioning.

Question - I am thinking about picking up a usb powered measuring mic from amazon to get some measurements of the drivers mounted on my intended baffle to then simulate a crossover using free Jeff B's PCD 7 . Should I bother with this or just use the already available .FDR and .ZMA files posted elsewhere?

Found RS52 measurements here - http://www.speakerdesign.net/raw/mea...onditions.html

Now, since Khanspire is using two of the RS225s in a sealed configuration that's what I am thinking about doing, since the ported enclosure would be significantly larger? http://www.divine-audio.com/khanspire/ . Since the RS52/RS28 don't require any of their own air space, I should be able to make the towers a bit smaller as well. Are the Khanspire sealed about 4.2 cu ft of air space for the pair of RS225s ?

**5th element** · 04 May 2015, 16:49 Monday

Originally posted by JeanM

Should I bother with this or just use the already available .FDR and .ZMA files posted elsewhere?

Absolutely you should bother with this as taking your own measurements are essential towards excellent end results.

**JeanM** · 04 May 2015, 17:07 Monday

Agreed. But, using measurements in something like PCD would at least get me on the right track , and I could then measure it and see how it's response compares to a simulated crossover?

Any recommendations for RS52 notch filter? I see some designs aren't even using it, and instead just crossing it low.

Would there be any cons to still using a notch filter to tame the RS52 EVEN if your highpass is fairly low or under 3k?

**JeanM** · 04 May 2015, 22:02 Monday

After about an hour of playing with PCD 7, I think I am getting the hang of it

**JeanM** · 05 May 2015, 02:44 Tuesday

Ooops, I'll need to double check the rs52 highpass point. Not sure what is going on there around 2200hz . This is based on available measurement files.

**Ray_D** · 05 May 2015, 06:00 Tuesday

Zaphaudio center channel

You should look at John Krutke's design: http://www.zaphaudio.com/ZDT3.5.html The sensitivities of the RS180 and RS 225 are very close. The center channel does not have full BSC; but, the cross-over topology is appropriate with a few value changes and a vertical WTMW layout. I built this with RS180s for my home theater. I'm on the road and do not have the changed values.

**Ray_D** · 05 May 2015, 06:07 Tuesday

Zaphaudio center channel

Originally posted by Ray_D

You should look at John Krutke's design: http://www.zaphaudio.com/ZDT3.5.html The sensitivities of the RS180 and RS 225 are very close. The center channel does not have full BSC; but, the cross-over topology is appropriate with a few value changes and a vertical WTMW layout. I built this with RS180s for my home theater. I'm on the road and do not have the changed values.

I missed you are using RS28s. Still good to look at though.

**Ray_D** · 05 May 2015, 08:04 Tuesday

More Comments

Rational, I hope. These are all high value drivers. I have used all of them, just not in this arrangement. The RS52 and RS28 are a bit of an odd couple. The RS52's strength is to go high and the RS28 can go fairly low. Some designs go as low as 1000 Hz. The RS52 should probably not be crossed lower than 800Hz to the woofers. This is the reason that JohnK went with a 3.5, I think. I went with a WTMW instead.

You should make measurements to get phase with respect to a common reference such as the baffle. If you reverse the mid you can see if you get cancellation indicating good phase matching at the crossover.

**JeanM** · 05 May 2015, 13:35 Tuesday

Hi Ray, thanks for the comments ! I have looked at the ZDT3.5 as well, will play with John's notch filters and see what the simulation shows. I am set on the RS28A though, it's about the drivers that I already have on hand and it should still work fine crossed over 2-3k I think. Now, for the RS52 I need to investigate this further to confirm if it can cross at 600-700hz 2nd order electrical to the woofers below it. Trying to keep the crossover count low(er), 2nd -3rd order electrical are my targets.

I plan on getting a measuring mic. I have a spare PC I can install my good old m-audio audiophile 24/96 card if need be, otherwise looking at one of the USB measuring mics from Dayton on PE/Amazon.

**ericnhitterdal** · 29 June 2015, 15:49 Monday

Any updates on this? I'd like to use two RS225Ps (4 ohm) an RS52 and an RS28F in a WTMW type setup for L/R/C and Side Surrounds. I'd love any kind of help/advice with crossovers for this project as I've never designed a crossover, but I can follow a schematic (or pictures) and can also solder.

Thanks, and don't mean to hijack this.