RTi A7 and RTi A9 Crossover frequencies Woofer Mid Tweeter

chijimi

From the polk audio webpage, I am seeing that that the RTi A7 and RTi A9 have different crossover frequencies, and I wanted to discuss the numbers along with perceived tonals of each speaker.

RTi A9:
Midrange/Woofer Crossover Frequency: 120 Hz
Tweeter/Midrange Crossover Frequency: 1,800 Hz

RTi A7:
Midrange/Woofer Crossover Frequency: 125 Hz
Tweeter/Midrange Crossover Frequency: 2,700 Hz

So my interpretation is that the dual 5.25 mids in the A9 can hit lower than the single 6.5 inch mid in the A7, however, I am confused about the tweeter crossover, why is it that the crossover is so much higher on the A7? My first impression would be that the A9 should be able to hit higher than the A7 in the mids. Actually the 900 Hz difference seems significant. Is there any difference in the tweeters in the two series? Can anyone describe to me the tonal differences from the tweeters crossover between the two speakers?

People often give the impression that the RTiA series has a very bright high frequency response and so I wanted to know if there are differences between the A7 and the A9s owing in part to the extended midrange response in the A7 over the A9.

K_M

The mid crossover is essentially the same.
They do use the same tweeters, but the difference in crossover frequency, is most likely due more to either rising response in the mids in one driver or the other, or to avoid cone break up, where midwoofers loose "Composure" when forced to do higher frequencies.

Normally a 6.5" mid woofer would be crossed lower, so not sure what the reason was.

Yes all of the Rti and Rtia series have somewhat boosted highs, that some like and so do not like so much. It depends a lot on the room, type of music and personal preference.

gp4jesus

chijimi wrote: »

From the polk audio webpage, I am seeing that that the RTi A7 and RTi A9 have different crossover frequencies, and I wanted to discuss the numbers along with perceived tonals of each speaker.

RTi A9:
Midrange/Woofer Crossover Frequency: 120 Hz
Tweeter/Midrange Crossover Frequency: 1,800 Hz

RTi A7*:
Midrange/Woofer Crossover Frequency: 125 Hz
Tweeter/Midrange Crossover Frequency: 2,700 Hz

Those Tweeter/Midrange XO frequencies is the point their respective response curves actually cross - not the drivers’ F3s. If you’ll check the Polk web site, you’ll see the ‘A1 TM XO Frequency is also 1,800hz. However...

Years ago I read a very detailed review on the A1. He had more graphs & charts than I thought possible for a speaker review. To my point, the reviewer listed the tweeter’s actual F3 much higher. His graph showed the drivers’ curves “crossed” at 1800hz, also illustrating a somewhat significant dip there in the total response.

Many tweeters won’t last long w/a 2nd order f3 below 3K**. I believe the RTi A series speakers, in varying degrees w/one exception* that I know of, use 2nd order HP and LP filtering. The RTi A7* mid is the exception: NO, NONE, ZERO HP filtering to the mid. 125hz is the LP spec for the woofers.
** EXOed, 4th order, these tweets seem OK @ 2K but that’s for another day.

The ‘A9 is one RTi A series tower/bookshelf speaker XO I’ve not laid eyes upon. I can not say if its a true 3 way. That is, are the mids HP filtered? The mids: are they or are they not cascaded* to the tweeter like the ‘A6 CC. Given time, Trey (VR3) or some else who’s screen name escapes me may chime in. To answer the question of mids “hitting” higher or lower...
* different XO frequencies: 1 mid 1.5K, the other 3.8K

I hope we satisfied your curiosity. BTW: I’m not clear on the point of your thread.

K_M wrote: »

...all of the Rti and Rtia series have somewhat boosted highs, that some like and so do not like so much. It depends a lot on the room, type of music and personal preference.

Take it from me*, that “boost” is distortion due to CHEAP XO components. A few $s and some time and you can radically “turn down” the boost. Several forum members decided they disliked the “boost.” So much so, have either taken the time and trouble themselves* or paid someone else, VR3**, to do the deed. I* went electronic. Bi-amped & tri-amped the problem away. You’ll find the details in my A7 and A6 threads.
**turn this into a side business

https://forum.polkaudio.com/discussion/175612/tri-amped-csi-a6#latest
(K_M: in the last post of the above, you asked me about the CC XO)

https://forum.polkaudio.com/discussion/99538/will-they-rti-a7-soften-over-time#latest (my Tri-amp thread)

Sorry for may be the derailing of the OP’s thread and getting so long winded. Kids waking up. Gotta go make breakfast

Tony