ER18RNX in my Polks M10

This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
I'm trying a pair of ER18RNX's in my Polk Monitor 10's but they seem to flubber some when I go to 21 or 22 in volume(out of 30) on my Sony's got 100w per channel maybe 120 at most.

These are supposed to be 80 watts speakers each.

Do you guys think my older crossovers can be doing a bad job?

I pulled the crossover out of the other M10 and tried it as well but got the same's as if the speaker seems more sensitive to bass than the original polks....and maybe even the cheesy pair of Nippons that my pops used to replace on 1 of the units!!!

If I push them some they kind of start to crackle after the flubbering I just back off.

They do sound nice and really precise....but I don't really want to sacrifice power capacity or bass.
Umm.. pretty sure it's because the cabinets you have them in are not designed for those drivers. What is the size / design? I'm guessing since it's a commercial speaker cabinet it's probably vented and it's making the driver reach it's xmax before you reach it's maximum rated power. Also, if it's vented you probably have a nice big hump in your response curve somewhere. You can take the enclosure specs and model it in a program like WinISD to see whats really going on.
The ER18 is best used in a ported enclosure on 14 to 16L per driver. So in your case you need 28 to 32L. As for the tuning frequency, it's up to your preference. If your enclosures as sealed and want to keep it that way, I think you want to go larger then 32L... I think?!?!?

The hard questions are: How is the x-over built? Is it close enough for the ER18?

diyAudio Member
Joined 2004
If the cabs are ported, try stuffing some socks in to block it up. You may or may not notice a difference.

Really though, what your doing is far from optimum. Pull the drivers out of the Polks and build a box and crossover that's made to work with them.
The box is 1.94 cu ft.

It's arraned with a tweeter up top...

then about 6 inches below it a pair of mids/bass drivers....side by side....

below it is a passive raditor 10"

in between the 2 pair'ed there is a dividing board but not enclosing each speaker from each other. just maybe for support...or some acoustic purpose it is about an inch thick and 4 inches top to bottom...and obviously goes about 10 inches from the front to back of the box internally.

There is stuffing throughout the box from it's original design.

these are them:

I'm trying to give them a modern day upgrade....and would also like to re-do or replace it's crossover.

It's a 2 way design......that from what I recall in my youth did not need a seperate subwoofers as they were quite capable. I was seeking to extend their capacity(possibly in the midrange) without sacrificing any older attributes using modern day drivers.

Didn't think the idea was too far fetched after reviewing the current generation of speakers and their much wider attributes compared to yesteryears.

I like these always have..dont reeally want to trash them. And dont reeeally have the time to build a box from scratch. But am willing to solder up a X-over and pop in new-er speakers.

My pops thought they took up too much space. So I saved them from the scrapyard and gave up space in my smaller living room in homage to how well they would reverbetate Dire straits "money for nothing" all the way up to the 6th floor from the 2nd when I was say 13.
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.