What a difference a sub makes!!

[ClaudeJ1]

While I was busy designing my own bass horn to replace the FH-1 bass bin in my Avatar, with some soon to be reconed EVM 15L's, my EQ unit crapped out. So I finally hook up my DCS2496 Digital Xover to control just the bass bin (cheap Scala, eh?) which contains a K33.

What I discovered is that the 300 Hz. suckout I was suffering from came from having too slow of a slope on the woofer over 350 Hz. going into the K 402. By simply going to a Linkwitz-Riley 24 db/oct. band pass between 35 and 400 Hz. the suckout completely dissapeared. Now onto the bass.

[ClaudeJ1]

I like the automatic detection of DVD/Blue Rays VS. CD's in my Panasonic BD player. In concert with my Onkyo, it automatically switched to 2 channel with SUB whenever I listen to CD's. I still wanted decent sound without the sub for late night listening. Even thought my "coffee table" tapped horn mouth is at my feet in the sweet spot, it still penetrates the walls, even at low levels, when neighbors want to sleep. So I was simply turning it off, but the bass was too weak from just the FH-1.

So applying an 8 db cut at 135 Hz. got rid of the peak that plagues this bass bin (and all older LaScalas too). The only thing remaining was the 10 db basss boost at 80 Hz. and I got some really flat response from about 50 Hz. to 350 Hz. with easy. It just took a while to find the right Q for the filters, and measuring with Room EQ Wizard on a laptop.

When I turned my receiver's Audyssey Auto EQ one, it chose a Xover point to the Sub at 70 Hz.. I tried manually over riding this to 60, but it only reduced the total bass when the subwoofer, so I went back to the original Audyssey pick.

Here's the curves showing with and without the sub. Listening to most music without the sub is still very good, but it has a FULL dimension when the sub is on, much more impact in the super low bass notes, which are present in many good recordings of recent times. When I listen at night, I avoid those CD's and listen to music without super low bass content and I'm happy, since most of the music is above 70 Hz. anyhow. Here are the composite curves:

[ClaudeJ1]

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.