[Brian Cheney]

Now that several RM 30's and 40's with the PBS and accompanying subs with our modded PE plate amp have shipped, I will pass along some recent experiences.

The parametric EQ on the amp can prove useful in unexpected ways.  Using a powered Larger Sub with a pair of RM 30C's, I ended up with a primary xver point of 40Hz (first calibration mark clockwise of 30Hz, the minimum setting), a low level (about 8 o'clock on the volume), and EQ settings of 60Hz, Q=.25, and max cut in EQ level. In response, the whole system transformed itself into an imaging monster with dynamics of posterior-propelling proportions.  A lot of this is overcoming the floor-to-ceiling room mode, of course. 

If you have 30's or 40's with the PBS, investigate using the EQ to tame
71Hz (8ft ceiling), 63Hz (9ft ceiling), or 56 Hz (10ft ceiling) modes by carefully adjusting Q and level, after setting EQ frequency to one of these numbers depending on room height.  My ceiling slopes from 8 ft to 9 ft which is probably why I ended up with a 60Hz EQ setting by ear.  Just go very slowly with the level, frequency and Q controls.

Try this and post your results.

[zybar]

While none of my VMPS speakers had powered woofer sections, I was able to do much more than what Brian suggests using my TacT 2.2x  with a pair of RM 40's + two Larger subs.

In general, addressing room issues with proper placement, room treatements, AND some form of room or speaker corection will always improve the areas Brian mentioned.

BTW, the improvements were never subtle...

George

[Corbin Johnson]

Brian,

This is very helpful information.  I've had my plate amp for over a year and never utilized any of the equalizer features because I have the Low Pass Frequency (xover) set at 40 HZ.  The manual says the Low Pass Frequency is used to establish the highest frequency that the subwoofer will reproduce.  Therefore, I assumed that the equalizer would have negligible impact altering the frequency between 20 HZ and 40 HZ on my larger sub.

I set the equalizer exactly as you suggested, and noticed a big difference.   I feel more bottom end without the sub overlapping the lower and mid bass of the main speakers.   The cross over must not cut off all frequency above the setting as the manual says if setting the EQ-Frequency to 71 HZ, EQ-Bandwith at .25, and max cut in the EQ-Level makes a noticeable difference. 

Thanks,

Corbin

[Brian Cheney]

It's amazing, isn't it?  Room problems you're used to hearing just vanish.

The TACT should work fine, but with the PBS/plate amp you don't have to digitize your analog sources and it's very cheap to implement.

[John Casler]

The cross over must not cut off all frequency above the setting as the manual says if setting the EQ-Frequency to 71 HZ, EQ-Bandwith at .25, and max cut in the EQ-Level makes a noticeable difference. 

Thanks,

Corbin

That right CJ.

Except for some very sharp digital slopes, most filter type crossovers have the old slopes, so the upper frequencies gently roll off decibel wise.

That is why I always tell people to set their dials very low.

If you listen to the SUB by itself and you can hear voices clearly, unless it is the BASSO or Baritone, the sub is set too high.

[warnerwh]

I've noticed notching out the bass peaks makes the midrange clarity much better. The room modes we all have definitely need to be tamed for the best sound. The built in amp is the perfect place to start as you also are biamping.

After using my RM 40's biamped now for sometime I'm convinced you can get the best sound with some tubes on top. A hybrid in my case but I'm sure a pure tube amp may be more appealing to others. Dedicating an amp to the woofers makes life on the planar/ribbon amp an easy task too.

[Eugene2]

OK, I'm dumb so what, if you don't ask you can't gain knowledge.  When you refer to max cut on eq, do you mean all the way left (counterclock wise) or max to clock wise.  Help me please!  Also, if you have the larger sub would it benefit to add the PBS plate to OXO on RM30M, if so what would the benefit be?  Thanks

[Brian Cheney]

Maximum cut on the EQ portion of the PBS is fully counterclockwise on the level control.