Acoustic panels

[scorpio333]

I recently got a set of Tekton Pendragons for my main listening area and let's just say they have been a real challenge in multiple ways, such as their 88lb weight. Over the a past few weeks it's been a slow process of finding the right placement away from the wall, amount of toe in, etc to get the soundstage as wide and tall as I can get it. I got it pretty close, or so I thought. This past weekend I had a chance to really turn it up and was disappointed. It sounds fine up to 1/2 way on the volume, then the after that it goes shrill and distorted? Some users have reported the Pendragons bring out all the room's acoustic shortcoming or issues. It was recommended to me to look into acoustic panels for early reflection points. ACK, another rabbit hole of unknown depth...when does this end???

I got to reading and like most things in this world it's a heated debate of science vs myth and everything else, lots of nonsense to sift through. So I do what I often do, look for a cheap option to test before investing a bunch of time and money. I found https://www.lowes.com/pd/Owens-Corning-Thermafiber-Fire-and-Sound-Guard-3-in-x-15-in-x-47-in/5001729147 at Lowe's $14 cheaper than Home Depot. Lowe's didn't have it on the floor, so I had to wait 30 minutes for them to get it down from shelves. They said it's a brand new product and they didn't have room for it yet. Anyhow, got the stuff home and made two rough draft panels by wrapping old bed sheets around the batt to keep the stuff from floating around. I put one panel on each side for early reflection points and was very pleasantly surprised/shocked. Most striking was the clarity around vocals and the speakers mostly disappearing. For years I never really gave thought to the actual room being an issue, not my/i] room, my room would never do that!

[Sir Thrift-a-Lot]

I've been meaning to look into this sort of thing myself.   I'm mostly happy with the room sound except the sub is, I don't know, uncontrolled.   It sounds great from the listening position, but if I move to the left side of the room it gets way too loud and it also drops off a bit on the right side of the room.   I'm not sure what the best fix would be, but experimentation is probably in order.

I guess because I am happy from the listening position I haven't given it too much thought.

[Sir Thrift-a-Lot]

I just looked at the link.   I've seen that stuff in high school gyms and similar uses.   It always cracks me up when someone paints over it as I'm fairly certain that ruins the dampening effect. 

[gdv]

Have you looked into tectum?  Eons ago when I was involved with my church?s sound system, we used their panels & results were better?. 

[Sir Thrift-a-Lot]

I Googled Tectum and found this site/product.   Attractive and cheap (compared to the big names anyway).

https://www.audimute.com/acousticolor-acoustic-panels

They do free acoustic analysis (which is probably like free water purity analysis from Culligan, but maybe it's actually useful).

[scorpio333]

Have you looked into tectum?  Eons ago when I was involved with my church?s sound system, we used their panels & results were better?.

Haven't come across that, going to look into it. If I understand things correctly, anytime you can absorb or smooth the reflections the sound become clearer or less distorted for the ears.

I've been meaning to look into this sort of thing myself.   I'm mostly happy with the room sound except the sub is, I don't know, uncontrolled.   It sounds great from the listening position, but if I move to the left side of the room it gets way too loud and it also drops off a bit on the right side of the room.   I'm not sure what the best fix would be, but experimentation is probably in order.

I guess because I am happy from the listening position I haven't given it too much thought.

As I listen alone 99% of the time, I've done all my setup for that one position. For the sub, I used the "place the sub where your head goes, then crawl around the floor to find where the bass sounds best, put your sub there" method. Thankfully, I no longer have the need for a sub in the two channel setup. The Pendragons do a good enough job going low. On certain tracks I do get some weird standing wave near the door to the driveway, to the point where it sounds like someone pounding on the door. Once I get a couple more permanent panels done, I may experiment with the leftovers to make a bass trap or two.

[MATT0404]

Nice upgrade to the Pendragons!  Sounds like either speaker or amplifier distortion may be setting in at higher volumes.  What amp are you using to drive them?

For room treatments, the best place to start (IMHO) is with measuring the speaker's in-room response to see what, if any, room issues you need to try to correct.  I have a calibrated UMIK if you want to borrow it sometime, or they're around $80 new and the software is free.  I could also bring it over some time and walk you through the measurements. 

Either way, before spending money, I'd start with some baseline measurements.  I spent a bunch of money on panels based on recommendations from GIK, but I found that it took less than half of the recommended panels to get relatively flat response in my room at the listening position. 

https://imgur.com/a/9DvgfOo

[scorpio333]

Thanks Matt. The Pendragons pick up where the Lores left off. Keeping the Lores for mains in the TV setup.

I'm using a Jolida 1102, it's a 20-25W tube amp. I don't often get the chance to go past 12 o'clock on the volume, my listening time is after the kids go to bed. I'd say anything up to about 1 o'clock sounds great, after that I believe the room reflections start colliding. Standing right in front of the speakers, I don't hear any distortion.

The room I'm using is also my wife's home office. So going nuts with the panels is not going to be welcomed. The room setup isn't optimal either, I believe it's 13x23 and it's setup with the speaker along the long side. With the speakers out 2' from the wall, they're fairly close.

I have a mic that came with my Scarlett 2i2, likely not a great mic but it's here. I'll be honest, I've been a little hesitant to get software involved. I'm sort of afraid it's going to paint a picture that will lead down a rabbit hole. We do plan to move within a year so for now I'm ok with a seat of the pants approach. Then again, some cold day in December I may completely change my mind!

[scorpio333]

I found this pretty interesting. I've been watching John's videos for a few years now, he's a little gruff here n there, but a brilliant mind. His woodworking knowledge and tricks are top notch. It's some sort of coincidence that right after the new speakers arrived he switched one of channels to audio based topics. Now I wouldn't choose plywood, but it's going to be interesting where this all leads.

http://www.youtube.com/watch?v=dsIqbJ55Z0k

[Sir Thrift-a-Lot]

Not only does that guy make all that stuff but then he edits videos together.   I wish I had half that energy.

[MacGeek]

If you are not too far away (or even in Pittsburgh), I have an RTA, calibrated mic and the associated gear to measure your speakers in the room.  I'd be happy to drop by.

I live in Pittsburgh's South Hills

[scorpio333]

If you are not too far away (or even in Pittsburgh), I have an RTA, calibrated mic and the associated gear to measure your speakers in the room.  I'd be happy to drop by.

I live in Pittsburgh's South Hills

I'm in Bethel Park. I've got a hectic schedule coming up for the next week or two. Once that settles down, I may take you up on that offer. Thanks!

[MacGeek]

I am not far, in Whitehall.  Let me know

[scorpio333]

Sounds like either speaker or amplifier distortion may be setting in at higher volumes. 

The gain from the JD9 was causing issues. While I like the JD9, it can be a real pain at times. What attracted me to it was all the loading and gain options. And now what I'm using is next to none of them! I'm using a AT OC9III MC cart. No matter what options I selected it led to compromises. Good on treble, then the lows get flabby and vice versa. Ultimately I found using the AT630 SUT was a perfect match with the JD9 set at 47k. So far, so good. Now setting the gain. The low outputs are way too noisy to use, so it's the high outputs with options of 55, 70, 85, 95db. 85 and 95 are just insanely ridiculous. Since the jumpers are on the back of the JD9, I rarely look at them. It was set to 70 for who knows how long.

Take a track like Pink Floyd's "Us and Them". While the song is bobbing along and mellow, everything is great - wide and open and great separation. Then the song hits the "Haven't you heard it's a battle of words" section and the highs distort. Keep in mind, I forgot it's set to 70 and start rolling in different tubes. 5751's tame it a bit but make it sound more brittle, 12AX7's just scream at you. At this point I'm thinking maybe the OP amps in the JD9 were contributing to the distortion. Pulled the unit of the rack and too it to the bench. That's when I saw the gain dip switch on. Switched the gain switches all off which is 55db. Hook it all back up and fire it up...much better...well mostly...I've got to turn the amp up sightly higher to get the same volume and some wideness got lost, but no more clipping/distortion so that's a win.

Since I can't leave anything well enough alone, my wheels are turning on how to find the point between 55 and 70 where things overdrive. I've thought about RCA attenuators or Lpads, but I'm not sure either of those would be neutral and uncolored.

[Jim Pittsburgh]

I also have a JD9 that I currently use in my garage system. I experienced much the same as you... so I chose to tackle the problem and ended up changing the OpAmps. Tried at least 4 or 5 pairs. lol  I finally found a set that I liked and have been happy since...... You are welcome to borrow it to get a look....