Invidiosulus

Dec 28, 2005 I ran into town with my younger brother Zachary to try to find some things at the store. Gifts that I hadn't quite had time to purchase before Christmas rolled around due to how busy things were at the house with Mom being sick. The store was closed anyway so I'd have to wait until after new years. My cell phone rang, an indestructible Kyocera that I'd gotten a a year and a half earlier when the old Motorola had died while everyone was out west for A.G.'s graduation. It was the home number but when I picked up it was my uncle George, " I'm sorry son, She's gone." I told him we'd be there in a little while and hung up. Zachary and I said a word or two and then drove the rest of the way home in near silence. Earlier in the week Zachary and I had been at the house when Mom woke up from one of her many naps. She wasn't feeling well started yelling and trying to remove her catheter. We went in and helped her sit up on the edge of the bed and I put my arms around her in a big hug and tried to hold her still. Because of the tumors that had been growing in her brain it had been some time since she was able to form coherent sentences. She babbled some gibberish for a few minutes before seeming to calm down. I gave her a squeeze and she looked up at me and Zachary and as clear as ever said "I want you to know that I love you. I always will love you."

I normally make some roast duck for Christmas dinner. We had cracked open a ham on Christmas Eve so I didn’t end up making the duck until yesterday. Brined in a pineapple-orange juice and fresh Thyme mixture and then steamed before a high temp sear in a cast iron skillet in the oven. Shallots and Chard were then cooked in a balsamic glaze made from the pan drippings.

It’s kinda funny, almost every time I tell @Marvel about some annoying/goofy things the kids are doing, he just kinda laughs and says it sounds familiar.

Making some sawdust. It’s not a Cornwall.

My buddy DJ’d a dance party at our local spot Saturday night. We had a good time but we were out way too late. yesterday afternoon I stopped by my other friends wood shop and we started putting a dent in a bottle of Angel’s Envy that our pastor gave him as a way of saying thanks for making coffee after church each Sunday. It’s pretty good stuff. This morning we got up and went to the Christmas mass and then came home and opened presents. the kids and I are adding to the ever growing fleet of Star Wars LEGO ships. Merry Christmas everyone! I hope your day is enjoyable and full of peace.

My oldest turned 15 today and requested some pasta for his birthday dinner. Bucatini Carbonara to be specific.

So you are saying that the AL5 needs a stand to not resonate? Or are you saying that it needs a stand to have the correct frequency response? What exactly do you propose would have been different if the AL5 had been on a stand. I think the measurements do a good job of showing what one can expect when listening in a real room. The review and the comments with the measurements are generally favorable.

I’m sorry that you have a problem with reading comprehension. The author states that they left the AL5 on the floor because it was so heavy. The measurement with the woofer disconnected was a a standard frequency response measurement and the author is acknowledging that the floor reflections were not allowing him to get an accurate picture of the response of the speaker which is why he only included the midrange and tweeter on that graph.

The AL5.

From the review in Stereophile.

REW is Room EQ Wizard, a free software that can be used to help tune an audio system. It has a signal generator function that allows you to output sine waves(or white/pink noise etc) to pinpoint certain issues. If used with a calibrated microphone such as the usb style UMIK, the software can be used to run frequency sweeps and give you measured results of frequency, group delay, etc. All things that can be really handy. I believe some of the group delay and waterfall style frequency/time plots would be helpful for actually measuring resonance vs input signal. But, you really need a calibrated mic to take advantage of it.

It’s getting a little chilly out here.

You gonna share that blunt or not?

Typically when a material decreases in thickness the amplitude of the resonance will increase and the Q of the resonance will decrease. So not only will the resonance be louder on the thinner piece, it will be resonating across a broader frequency. I measured this on the backs of my H1 with a small piezo transducer mounted directly on the wood while running frequency sweeps in REW. Increasing the thickness will reduce the amplitude but the peaks will still be in the same place although narrower. All of which is to say, I would imagine the AL5 sidewalls would resonate at around the same center frequency as the older models since the sidewalls are approximately the same size. But since they are thicker they should resonate less and over a narrower range.

That’s really funny.

Randy is full of misinformation. The top and bottom of the LS bass bin are adequately braced. It is only the large side panels that are an issue on the LS 1. Just like the 1/2” thick back panel on a Heresy 1, the side panels on an LS 1 will muddy the upper bass from its vibration if played at a louder volume. my LS cabs were stock thickness 3/4” and the braces provided a noticeable difference in clarity. Would I have gotten similar results from increasing the thickness of the sidewall? Perhaps, but the braces were a cheap and easy install compared to increasing the sidewall thickness.

Do you have formation on the reflections and specifically what they caused?

I mean, the non expanding section of the horn in the LS design causes unwanted results in frequency response, yet here we are decades later still using that design. It takes far less than 100 watts to excite the side walls in the original LS. Of course the industrial models and the AL5 are going to resonate less, that’s just the way physics works. The 1/2” back panel in the H1 is the same way. Bracing it or replacing it with a thicker panel improves the sound. the newer models don’t have the same issue. The original models were good but engineering and cost decisions were made that leave things less than perfect.

I might have said “known to resonate” instead of “known for its resonance”. Can you feel the sidewall moving when you are hearing the issue? On my LS 1 it would become very apparent on some songs and I could feel it with my hand quite easily. As others have said, clamping some additional bracing in the outside of the cab is a cheap and reversible fix that you can easily test and back out of if you don’t think it helps. the EQ setting I posted were specified by @Chief bonehead for folks using DSP when mounting the K510(I think) on top of the LS bass bin. The sharp notch at 148Hz made a world of difference on my LS 1. If you aren’t going active EQ then just concentrate on the rest of the equation regarding placement and room modes.

A second pair of Heresy’s makes a nice set of stands.

Yes, they resonate. Bracing will help a lot but it won’t tame some of the irregularities in frequency response that are inherent to the LS due to compromises in the horn expansion. if you have an active DSP setup that is capable of some parametric EQ adjustments, you can try the following settings that are known to ameliorate the response of the stock LS bass bin. 87hz, Q:3.5, +5dB 148Hz, Q:8, -7dB 380Hz, Q:5.5, +2dB

I wouldn’t trust any measured differences unless the speakers were both in the exact same position in the room.

Oddly enough, some people would like to have a tweeter that doesn’t run out of gas past 15KhHz and can handle a little bit more power. Plenty of stuff sells for silly amounts of money just because it is old and or rare. You are deluding yourself if you think there aren’t far better modern tweeters available.