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Sub on and off Curves


ClaudeJ1

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I usually listen at or below 5.1 standard levels of 85 dB at my sweet spot. It is the reference level here on these curves also. I used 1/3 octave smoothing, since it's how we hear music. As you can see from the curves, my -6 db down point is about 48 Hz. for the digital EQ'd bass bin. All I do is turn the power amp on and off to get the Subwoofer extension. The -6 dB down point for the sub is at 15.75 Hz. which is quite impressive on Blue Ray movies like Tron Legacy (with the inherent Hollywood +10 dB boost in the LFE channel). This setup has taken me a long time to tweak, but this is the flattest overal bass response I have ever had, with amazing detail, impact, and clairity. I can pick out every bass note played, even on 5 and 6 string basses that put out sound at or below 31 Hz. Long live well applied digital EQ on inherently non-flat horns and rooms!! If there's now super low bass content during daytime listening, the TH sub just ignore it, just like it's supposed to, but it's there when the music calls for it. The curves below are the response for 2.1 for music on CD's. For movies, I believe the LFE channel goes to the sub with a +10 db boost when it follows Dolby/DTS standards for processing, but I have never measured it.

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This setup has taken me a long time to tweak, but this is the flattest overal bass response I have ever had, with amazing detail, impact, and clairity.

This looks very nice. I also took out the peaks in room response from the Jubs, and the overall character of the room changed (dark green line - no smoothing applied).

Cask05_jub_only_spud_only_room_final.jpg

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This setup has taken me a long time to tweak, but this is the flattest overal bass response I have ever had, with amazing detail, impact, and clairity.

This looks very nice. I also took out the peaks in room response from the Jubs, and the overall character of the room changed (dark green line - no smoothing applied).

Cask05_jub_only_spud_only_room_final.jpg

Aha, you are the guy with SPUDS. Very good. Your twin 8's have a bit less Sd than my single LAB12, but since you have 2 SPUDS, you have about 1.5 X more Sd than I do in an 18-20 ft. Tapped horn, so your low end extension is similar to mine.

I helped a friend build 3 SPUDS for his new HT room and they are Amazing, I can totally relate to another TH owner. It's the best compromise out there for low group delay, lowest frequency extension, transients that match folded horn bass (albeit with a 70 hz. top end only on a TH). Long live Tom Danley, eh?

the ONLY reason I don't have 2 in the corners as you do is because I live in a small condo with poor sound insulation to my 2 neighbors. Having mine as a "coffee table" puts the mouth at my feet........Audyssey says 2.5 feet from my head, but it's physically about 5................anyhow that proximity give me the super low bass at my ears without putting as much sub bass into the entire room. Thank goodness they are in a finished basement with concrete walls, but when I tried the corners, my OLDER neighbor knocked on my door to complain that her pictures were moving on the wall. Sounds funny here, but not funny to a neighbor.

BTW, I just got done working on a set of Jubelike Drone bass units (two active 12's and one passive 12) with a forum member. I got some interesting measurements I will talk about at a later date. He has two DTS-10's, so you can imagine what that must sound like, eh?

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...when I tried the corners, my OLDER neighbor knocked on my door to complain that her pictures were moving on the wall...

My bedroom is directly upstairs and my wife mentioned one morning that when the kids were over for a later-night movie with their significant others, the pictures were moving on the wall and even the bed jumped a bit on the "explosions". (I was downstairs watching, too.) [H]

Actually, I need to stiffen the corners more. That should be a summer project when my wife is off visiting her family in San Diego. [ip]

Chris

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So what do the unsmoothed curves look like?

What is a sane and relevant level of unsmoothness? 1/6th, 1/12th? 1/24th octave?? My vote is for 1/12th because that represents each note in a scale, right? Or whatever you like.

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1/24th and unsmoothed are usually very similar. Your plots are showing your extra extension which is really quite surprising on how many recordings that matters - I was just more curious about the room mode behavior (which shows up much narrower in the frequency response).

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I was just more curious about the room mode behavior (which shows up much narrower in the frequency response).

For the casual observer of this thread, below the so-called Schröder frequency of the room (also known as the sparse mode region), room modes are further apart and easier to identify on the FR plots. In most home listening rooms this is up around 200 Hz but it can be lower, for instance in my room it is calculated to be 126 Hz and it is easy to see in my room setup FR plot, above.

Chris

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I"m not sure of what my room modes are. I only have side wall home made absorbers that were given to me by a friend who built a new HT room and didn't need them anymore......F unknown . Otherwise I have a computer workstation, drop ceiling (only 7 ft), thin paneling walls behind the rear channels room dimensions about 15 x 20, with another additional 10 ft. behind the thin wall, so for the super low end, I guess it's more like 15 x 30.

The software is on my laptop, so I will pull up the curves at 1/24th, take a snapshot, and repost. I'm am curious also.

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Here's the expanded view to 400 Hz. with no smoothing (1/48th resolution)............still very good........Audyssey on with and without sub, just a power off switch on subwoofer amp. I tamed the FH1/K33's 130 Hz. peak with a fairly low Q 10 db cut and did a 3 db boost at 80 hz with the DCX2496/woofer amp. Mid and Tweet each single cap from the receiver amp.

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I was just more curious about the room mode behavior (which shows up much narrower in the frequency response).

For the casual observer of this thread, below the so-called Schröder frequency of the room (also known as the sparse mode region), room modes are further apart and easier to identify on the FR plots. In most home listening rooms this is up around 200 Hz but it can be lower, for instance in my room it is calculated to be 126 Hz and it is easy to see in my room setup FR plot, above.

Chris

lol, I love how that's your casual observer description [:D]

Btw, that looks better than most rooms Claude...you're not getting super deep anywhere. Do you have plots with Audyssey turned off too?

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Btw, that looks better than most rooms Claude...you're not getting super deep anywhere. Do you have plots with Audyssey turned off too?

Somehow, I knew you would ask me for that Mike. You are like the National Enquirer of Audio.

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I was just more curious about the room mode behavior (which shows up much narrower in the frequency response).

For the casual observer of this thread, below the so-called Schröder frequency of the room (also known as the sparse mode region), room modes are further apart and easier to identify on the FR plots. In most home listening rooms this is up around 200 Hz but it can be lower, for instance in my room it is calculated to be 126 Hz and it is easy to see in my room setup FR plot, above.

Chris

Linkwitz' approach to sound reproduction really blows my mind. He is a Dr. Non-Linear System Compensation EQ man for sure. Beyond the scope of my text. LOL. There's a reason why he and Riley revolutionized pro sound reproduction in all Digital Xovers in the world today.

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Btw, that looks better than most rooms Claude...you're not getting super deep anywhere. Do you have plots with Audyssey turned off too?

Somehow, I knew you would ask me for that Mike. You are like the National Enquirer of Audio.

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