Polk Audio RTiA7 Mod Thread

[mdaudioguy]

These last 2 issues are points of contention I've had w/both Polk Customer service and a forum member who shall remain nameless for the moment. I'd greatly appreciate 3rd party confirmation on these.

thanks for indulging me by reading this far. tony

Why don't you try some divider mods and report back? You're right, there's no divider - so? Polk doesn't bill these speakers as being the ultimate in audio. RTi is their mid-line, and it's geared toward HT anyhow. Why would you argue with CS about it? Your posts are becoming repetitive... Time to take action - what are you waiting for?

[Face]

In a ported speaker, I wouldn't bother. Besides, it could alter the voicing of the speaker enough where some crossover adjustments would be need.

[VR3]

I do not like the boards on the RT series. In comparison to what Def Tech and Monitor Audio uses - I would consider their board quality to be substandard. Not to mention the soldering seems sloppy in comparison to the LSi. (Just my observation)

[gp4jesus]

thanks maudioguy for saying oh so politely, "stop whining! Get off your duff & do something about it!"

Why don't you try some divider mods and report back?

I will. A lousy excuse: planning to relocate soon; they're in boxes.

Your posts are becoming repetitive...

you're right! I've wasted too much of others "action-based" time. I'll limit any future communiques' of these subjects as PMs to 'A7 owners.*

Time to take action

As soon as we're moved in.

[VR3]

Alright - here we go!

Im waiting on resistors from Canada - so this is my stopping point for now!

[jbooker82]

Looks good, cant wait to hear them.

[VR3]

Me either - It always amuses me how these awesome crossovers sound with free air drivers ;)

But seriously - cant wait to hear your impressions! I am sure you will love the change!

I like constructing these - its kind of like a puzzle..

Thanks!

[jbooker82]

How tall are they going to end up being? You have a test bench you hook them up to test them out before shipping them.

[VR3]

Around 8" or so - Yes! I always test them out before I ship them back!

[VR3]

Alright!

Resistors are here except one - my fault - DOH!!!

But I think they turned out pretty bad ass if I do say so myself!

[VR3]

Not to add fuel to the fire on a previous discussion but there is -zero- high pass filtering on the midbass. It is playing everything.

Odd design

(I have them running free air)

I am also using a bi-wire cable as well

[jbooker82]

That looks like a lot of work.

[VR3]

lol

I tell ya what - soldering the top caps on to that board in that 1.25" space was a treat!!

[F1nut]

Do you think there's a concern with the plastic tabs breaking off the binding post plate with all that extra weight hanging out so far? Not a criticism, just my own curiosity.

[gp4jesus]

Alright!

Resistors are here except one - my fault - DOH!!!

But I think they turned out pretty bad ass if I do say so myself!

WOW!! Awesome out-of-the-box work! Nice pics.

[VR3]

Do you think there's a concern with the plastic tabs breaking off the binding post plate with all that extra weight hanging out so far? Not a criticism, just my own curiosity.

I would guess not - the metal rods go in pretty deep and I actually pulled on it pretty hard with very little stress.

I think think should be good for the long haul!


Thanks guys!

[EDUBAG]

would you mind sending me via pm, how much a mod like this would cost. i have always wondered about the full potential of the a7.

regards,

eduardo

[VR3]

With the CSiA5 thrown into the mix it was right around 319 bucks - so I am guessing.... 220-250 for the RTia7...

Obviously that is with the parts used here

[VR3]

Assuming all of the woofers are 8 ohms (I am using 8 ohm woofers for the load) - the crossover measures out at 5-6 ohms vs. 8 ohms -- very interesting

[Face]

Assuming all of the woofers are 8 ohms (I am using 8 ohm woofers for the load) - the crossover measures out at 5-6 ohms vs. 8 ohms -- very interesting

Even if you had the correct woofers there, you would need a woofer tester or similar tool to know the real impedance of the speaker, measuring across the binding posts only tells part of the story. As you see, the crossover itself can have a large effect on the speaker's impedance.

[VR3]

Gotcha - well that should be here tuesday so we will get to the bottom of this! HAHA!

[Outfitter03]

Assuming all of the woofers are 8 ohms (I am using 8 ohm woofers for the load) - the crossover measures out at 5-6 ohms vs. 8 ohms -- very interesting

I might be guessing wrong, but you may be confusing resistance, as measured with a voltmeter which is purely DC resistance with Impedance which is AC resistance or Z. This is ac frequency dependent. This is a much more complicated measurement that consists of true resistance and capacitive and inductive resistance. A meter to measure this is something like this.

http://www.teknetelectronics.com/Sea...&Fluke_PM6303A


http://www.teknetelectronics.com/Dat...m630X80408.pdf

[VR3]

Yeah I ordered the Dayton measurement software with test leads and scale yesterday - so it should be here Tues/Wednes

[Outfitter03]

That sounds pretty cool and doesn't look like it will break the bank to buy. I would like to see your review of this when you get it.

I would think that the nice poly caps should be dropping the impedance quite a bit from the cheap electrolytics in the original crossovers.

[Face]

I would think that the nice poly caps should be dropping the impedance quite a bit from the cheap electrolytics in the original crossovers.

How?

[jbooker82]

Yeah I ordered the Dayton measurement software with test leads and scale yesterday - so it should be here Tues/Wednes

So do my xo's will get the full treatment then?

[VR3]

Yep - I have already ran yours free air and I put a volt/ohm meter on them. Everything seems fine - I will definitely check them with the software as well!

[VR3]

Polk Audio CSiA5

[Outfitter03]

This is on the edge of my HiFi physics but I will put myself out there for the masters to educate. So to the the best of my understanding:

All capacitors have a rating of DF or Dissipation Factor for AC.

The DF for most Poly Caps is very small, fractions of a percent so they are close to an ideal capacitor.

Electrolytic Capacitors have different DF ratings depending on quality, but 10% is probably standard for inexpensive capacitors.

This higher DF rating results in a larger reactive load or put another way, impedance.

http://en.wikipedia.org/wiki/Dissipation_factor

[jbooker82]

I am starting to worry about the pressure of doing a review since I only power them with a Onkyo TX-NR808 avr, and dont have an audiophile ear.