Looking for feedback on room and REW data

[Charbugg]

I have been putting a new room together and trying to get my system up and running after a move into a new home. Honestly it feels like starting over. The room is 25' long and 18' wide with 8' ceilings. I am trying to utilize the room treatments I had in my previous home, and I am finding it challenging. The system is the first generation underground Klipsch Jubilee's with the Klipsch KPT-1802 sub. I am all digital and will utilize DSP (audiolense) with the help of Mitch Barnett to help finalize my setup once I have the room dialed in the best I can. My measurements that are attached are utilizing DSP to only do my crossovers and time align my drivers.
I am not happy about placement of the SUB because it has completely removed the use of my entertainment center, but every other location I tried, the room modes where just too great to overcome. Trust me, I tried the back, sides, and every other place I could and moving a 330lb sub is not easy.
My listening position is exactly 15' from the front entertainment center and this took days to determine through hundreds of measurements. Bottom line, allot of work went into the placement of everything.
I have attached some pics and some REW data. Please look at the data and give me some feedback on things that you feel needs to be corrected to improve the setup.

Thanks,
Rob

 

[Charbugg]

MDAT file is attached here. I compressed it. Hope you can open it

 

[Keith_W]

Welcome to ASR. Have you read the eBook in my sig?

I am sorry if this comes across as brutal, but this is horrendous. Particularly for a system where DSP has already been applied (as you say?). There are a lot of problems here.

1. Huge dip at 25Hz in both L/R channel, and bass that is at least 15dB too soft. Without an independent measurement of your subwoofer, I don't know what is happening here. You need to take this measurement: L and R speakers without sub, and sub alone. All with the same timing reference.

2. Huge cancellation between 400-800Hz. Given that it is evident in both speakers, I am guessing this is a crossover summation error. I suspect you would benefit from inverting the polarity of either your woofer or your midrange. If you want to know, obtain measurements of your woofer and midrange independently WITH a timing reference. This is assuming that your drivers can be driven independently. I don't know much about your speakers, there is a Klipsch expert on ASR @Chris A who may be able to help.

3. What happened to all that treble above 5kHz?

 

[Chris A]

Hi Rob. Nice to see you here. (The K-forum has basically died, unfortunately. It's been about 5 years since I last was there.)

As I understand it, you are wanting recommendations on the placement of loudspeakers and acoustic treatment, and you've provided the raw uncorrected REW measurements to help in that purpose, but not to help in the EQing and crossover parameters. You said that you are planning to get help from Mitch on that part of the puzzle. Is this all correct?

As far as I can see, you've only provided a left/right Jubilee measurement, and not the horn sub measurement. I would recommend adding that sub measurement to this thread, taken at the main listening position(s), slightly off-center from the room's centerline (left to right).

Here is what I see on the reverberation response of the room from your listening position measurement at the couch:

This is good, if not a bit overdamped for Jubilees with their full range directivities, with measurements taken at the listening position.

If you had taken the measurements with the microphone at 1m in front of each Jubilee (on-axis with the K-402 centerline in the vertical plane), you would have noticed the "EDT" (early decay time) cyan colored trace effectively drop to 50ms or lower, and the group delay plot (including excess group delay) also drop to zero above ~1 kHz, which also smooths the phase curve plot to remove the excess phase introduced by the room's reflections (which can't be EQed).

I also see the bass roll-off of both Jubilee bass bins, since you've not placed the Jubilees in the room corners (as the loudspeakers were actually design to be). You obviously are going to rely exclusively on the 1802 subwoofer below 60-70 Hz. In order to understand the crossover to the sub, a measurement of the sub is needed here to see the room modes and any issues with selecting the subwoofer crossover frequency.

As far as placement of the acoustic treatments, they look pretty good. I've already mentioned that pulling the Jubilees out of their corners has killed their bass response below 70 Hz. You might try moving the Jubs back into the front wall room corners to see what occurs with their bass response. You're giving up a great deal by denying them the opportunity to act as corner horns. A little extra absorption on the side walls just next the horn exits will serve to control any midrange early reflections that you incur by moving the bass bins into full corner loading.

I did a quick EQ look using REW to flatten the response. It looks fine after ~6-7 PEQs are used (IIR filters only). Your phase response (high frequency to low frequency) grows to 270 degrees due largely to the fact the K-402s are too high off the floor while sitting on top of the bass bins. I rotate my K-402s down and forward using the four-bar K-402-HF assembly mechanism to reduce their height as much as possible, and it allows me to get much flatter phase response down to 60 Hz or so.

What else can I help you with?

Chris

 

[Charbugg]

If you are curious, Here is a file with correction on it. I had a file generated that got me up and running while I dialed in the room. Since having this file generated, I have moved things a little to try and dial in the room. Obviously once I get the room dialed in, I will get a better correction.

 

[Charbugg]

I appreciate the feedback and your time.
I need to clarify, the REW data with room correction was taken after moving many things around extensively trying to go after some low end bass issues. So it changed everything dramatically but it does provide a good illustration on how moving speakers, listening position, and absorption only a few feet changes everything.

To answer some questions, I am attaching some more data that may help. All data on this file was taken with the mic at the listening position on the couch. This file has data showing the SUB without crossover applied and with it applied, it also has sweeps of the left and right bass bins with no crossover and crossover applied, and finally a measurement of the left horn with crossover. I know Chris can relate to this setup as he has seen data from my setup before in my previous home.

Unfortunately, this room has been difficult to dial in and my primary goal here is to get everything as good as I can with the room, and then get Mitch to generate another file. The bad part of DSP is you have to cut everything so hard to correct that you end up with no headroom and my goal is to try to correct the issues that I can before DSP to gain that headroom back.

I am no expert in this field but I got my last room dialed in after receiving help from some great people, and I appreciate that help.

Rob