Dallas Mahler 2
- Hi Jeff,
Below is a camera phone photo of the DualCore's full frequency sweep measurement, in bypass mode (no EQ applied), of the Sterlings plus sub. I run the Sterlings full-range and let the sub fill in the bottom with a LP filter setting at 45Hz (24dB/octave) on the sub. As you can see there is a significant downward slope. (I hope you can see or enlarge the graph!). I'm still experimenting with toe-in. This measurement is taken with the speakers aimed straight down the room with no toe-in and with the mike 8 feet from each speaker. The downward slope above 1kHz is leveled considerably when aiming the speakers directly at the listening chair. However I do like this sound, at least for now.
The DualCore correction below 220Hz, with a +2 bass tilt added, does improve the bass and mid-bass by making it clearer and more focused. But even without any EQ applied the Sterlings sound VERY well balanced! (I had to toggle between EQ and bypass several times to decide which setting I preferred).
What the Sterlings do, which I love, is get the instrumental and vocal characteristic timbre correct, at least as I hear it. TM's description, in an earlier post, of his Spendor 1/2s is what I hear with the Sterlings but the midrange is as clear as any speaker I've had here!
For multichannel surrounds I use the Gradient Helsinkis. After EQing the Sterlings with the DualCore I run an Audyssey measurement from my Denon receiver of the four speakers (Sterlings+JL sub, and Helsinkis). I then set the Denon EQ to "L/R Bypass" mode which times the four speakers but only EQs the surrounds. The EQ applied by Audyssey to the surrounds in this mode is supposed to be a FR copy of the main L-R speakers. It works!
----- Original Message -----
From: Bomwell, Alan
Sent: Tuesday, January 15, 2013 06:25 AM
To: Bomwell, Alan
- Many thanks for this, Jeff! Very helpful indeed!
Looking again at your full spectrum graph, it seems that your system might benefit from increasing the upper limit of Dual Core Correction to 450 Hz.
In selecting the upper limit of Dual Core Correction is important to choose a frequency which is NOT at a DIP as Dual Core will stitch the corrected level to the uncorrected level at the upper frequency limit of the correction.
After running the correction to 450 Hz, you could use the Room Analysis feature to produce an on-screen display of both the Before and After Full Range response overlaid on each other.
Here is the procedure given to me by Tim Ryan of SIMPLFI Audio to get such a measurement. It can be viewed on the Built-in screen OR exported to FREE Room Equalization Wizard (REW) software for analysis on a bigger screen.
1) Capture the un-corrected FULL Range Response
a) Press the Orange Bypass button on the remote and ensure the Red ' Bypass Bars ' appear on the screen.
b) Navigate to the Room Analysis Main menu and press ' OK '.
c) Select ' Make NEW ' > OK.
d) Select Channel ( Left, Right or Both ) ... choose ' BOTH ' and press ' OK '.
e) Select Frequency Range ( 200, 500 Hz or FULL ) ... choose ' FULL ' and press OK.
f) DC will emit pink noise.... jog the volume until the screen says ' Volume OK ' and press OK.
g) Dual Core will now sweep the room from 20 Khz down to 15 Hz .... the room should be completely quiet while making this sweep.
h) When the measurement is done, press OK to Close / Store.
2) Capture the corrected FULL Range Response
a) Exit the Room Analysis mode by pressing 'Back' three times until the screen shows the top level INPUT/OUTPUT screen.
b) Engage the Correction (the two red bars should disappear).
c) Navigate to the Room Analysis Main menu and press ' OK '.
d) Select ' SECONDARY ' and press OK.
e) Dual Core will now sweep the room from 20 Khz down to 15 Hz .... the room should be completely quiet while making this sweep.
f) When the measurement is done, press OK to Close / Store.
3) View the FULL RANGE Before / After measurement on the Built-in Screen
a) Go to Room Analysis.
b) View USER press OK.
The Uncorrected response should appear in orange and the Corrected response in black.
--- In email@example.com, "jeff" wrote:
> Hi Al.
> Thanks very much for posting that pic! It confirms that you are getting serious correction of peaks, and that the Dual Core is not trying to fill gaps, at least not much. I can see why you said that the bass was tighter.
> --- In firstname.lastname@example.org, "Bomwell, Alan" wrote:
> > Hi Jeff,
> > Here is the before and after photo you requested. It is a screen shot of the both the Sterling plus sub corrected to 220Hz.
> > Regards,
> > Al