400hz 1khz ring +echo

[WaynePflughaupt]

Originally Posted by buggyboy

I'm looking to dampen our sanctuary to increase gain before feedback. right now we have a lot of ring in the 400 - 1000hz range. i've used eq to cut it as much as possible with my rane 15 band GEQ, but it still isn't enough. so now i'm thinking it's time to put up some acoustic panels of some sort.

I’m surprised no one has mentioned: The Rane EQ is a nice tone control, but it’s useless for feedback. Keep in mind that any equalizer will affect its rated bandwidth on both sides of the center frequency. The Rane is a 2/3-octave equalizer, which means you’re wiping out a full 1-1/3 octave of bandwidth trying to deal with feedback at a narrow, specific frequency.

I suggest getting a parametric equalizer. It will allow you to dial out your ringing frequencies with surgical precision, using ultra-tight filters 1/6-octave or less. If it’s the pastor’s mic that’s the sole problem, you can dedicate the EQ via the channel insert.

[buggyboy]

Thanks Wayne, you're completely right of course. I will start shopping for a 31 band parametric now.

any suggestions on brand or model? (keep the word "budget" in mind, I'm likely to pay for this out of pocket).

thanks again

[Gracetech]

Buggyboy i think you are getting graphic and parametric confused. If there even was a 31 band parametric eq made i'm sure it would be the furthest thing from "budget". I would look into a 5 band parametric to make sure you have plenty of control. You can always pick up a 3 band parametric pretty cheap though and stack two of them.

crt

[buggyboy]

yep, i mixed my metaphors a little there. I'd edit it, but i can't remember how.

[WaynePflughaupt]

Glad that graphic/parametric confusion was cleared up!

yep, i mixed my metaphors a little there. I'd edit it, but i can't remember how.

The "Edit" option is only avaliable for a certain time after making a post, not indefinitely.

Originally Posted by buggyboy

any suggestions on brand or model? (keep the word "budget" in mind, I'm likely to pay for this out of pocket).

If budget is the concern, there’s a Yamaha YDP2006 digital parametric on eBay right now. Lately three of these have sold for a piddlin’ $50, and the one that’s up now with a $50 opening bid has been re-listed, as it got no bids at all the last time (same with the one with the opening bid of $125, it’s on its third listing). This is a first-class equalizer that sold for around $2000 when it was new.

In addition to 6 parametric filters, the YDP also has 4 notch filters for feedback, and 24-dB/octave high and low pass filters. The latter would be helpful if the EQ was inserted on the pastor’s mic channel – you could just wipe out everything above and below the voice range (~300 Hz – 6 kHz) and entirely eliminate those frequencies as feedback potential.

The only caveat, an analog parametric is going to be more precise at nailing the exact feedback frequency. The Yamaha (like every digital parametric I’m familiar with) has pre-set frequency steps @ 1/24-octave intervals. In most cases this should be sufficient, but it’s not quite as precise as analog. The Rane PE17 and Ashly PQ / PQX parametrics are good analog units that can be had for reasonable prices on eBay, usually well under $200 (the Rane is more user-friendly, though).

Regards,
Wayne A. Pflughaupt

[Gracetech]

That's wild Wayne. My experience has lead me to believe the exact opposite. Most of the Digital parametric equalizers are capable of the same resolution as Analog. The cool thing is more and more digital EQs have phase correcting algorithms that smooth things out between filters that interact.

crt

[WaynePflughaupt]

Originally Posted by Gracetech

That's wild Wayne. My experience has lead me to believe the exact opposite. Most of the Digital parametric equalizers are capable of the same resolution as Analog.

That’s good to know, Chad. The Yamaha is an older model, from the early 2000s. I haven’t had the opportunity to get my hands on anything lately-made to see what they’re like. It seems these days that stand-alone EQs are going by the wayside, in favor of equalization being rolled into digital speaker processors and consoles.

Regards,
Wayne A. Pflughaupt

[buggyboy]

Hello again,

I've been tweaking and twiddling nonstop on this same issue, and thought I'd post here again instead of opening a new thread.

so, to recap,

I have a bare bathtub of a sanctuary, joined by a partition curtain to a bare bathtub of an overflow. there is so much energy in the 300-600hz range that my mics are picking up feedback long before the volume is "loud".

I've obtained a podium mic, and phantom power to use it.

I plan to stop using the bose speakers on stands and start using some ceiling speakers (voice only, instruments and singers will go through the bose).

I plan on getting a parametric EQ for use in tuning the room.

(those two actions should help greatly)

I have the opportunity to install some acoustic treatments in the room.

now, my question...what materials absorb what frequencies?
As I said, the ringing energy is from 300hz to 600hz.

\\\Insert all possible disclaimers here about hiring consultants, the dangers of DIY, and the use of diffusion\\\\\\

I feel that the biggest fish to be fried here is just damping down the reverberation hang time that is allowing ringing to build up and up into feedback.


Your help is most appreciated, Thanks.

[Tim Padrick]

I agree on the uselessness of 15 band EQ as anything but a tone control (or in the sidechain of a comp or gate - very nice!).

I've used parametric for some time now in the system processor, and also as an insert for problem channels or groups (for which I used a Rane PEQ55). (Now that I'm using a digital console, the Rane is available ).

[WaynePflughaupt]

Originally Posted by buggyboy

I have the opportunity to install some acoustic treatments in the room.

now, my question...what materials absorb what frequencies?
As I said, the ringing energy is from 300hz to 600hz.

I wouldn’t worry about treatments until you’ve determined that a parametric EQ won’t address the problem.

Regards,
Wayne A. Pflughaupt

[buggyboy]

small update:

I hooked up the ceiling speakers, they were part of an old 70v system and predictably sounded terrible. Not only muddy, but the cones would "fuzz" at anything approaching a good level. So that option died.

This last Sunday I used a newly modified wired lav (with windscreen) and mounted the bose speakers on low tables. the speakers were exactly at head height of the seated congregants. This was by far the best sound yet. I attribute it primarily to using the lav, but with the speakers at head height more energy was absorbed by the congregation and less was pushed into an endless echo.

Tried the same setup at the evening service, again great sound. It might even be good enough to stop tweaking...but i feel like it's a hack, a crutch. I should by rights be able to use my fancy podium mic.

I'm talking with cmchamp about speaker options...no conclusion yet.
I think the pastor is ok with the lav for now.

I'd like to try the parametric...but these purchases add up fast when it's out of my own pocket. the next buy is a bunch of connectors and cable to make some cables.

I'm also a tad worried about choking down the mid-range so hard. even as it is, I can tell the voice isn't quite right. of course, the parimetric might help there by killing the fundamental frequency and leaving the rest untouched. right now i have to use the geq and the 3 band on the mixer to kill almost all of the mid and low to get enough volume.

is it fair to say that in using eq to "fix" a bad room we are not really taking away the problem frequencies...but rather the room already amplifies those frequencies? meaning, i shouldn't feel bad for suppressing the frequencies that the room over-emphasizes?

thanks again.