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Sl3 bass resonance

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vimara

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Hi guys, I have already changed my new panels from the sequel II to my recently purchased sl3. The sound of the new panels is now brighter, I don't know if it will be due to the high voltage supply or the filter of the sl3, I suppose I will have to get used to it.
One thing that I don't quite understand about the sl3 is that it has a resonance peak at 76Hz that the sequel does not have, could it be because of the height of the wooffers? I have looked to make a notch in the filter but I would need an 8.3 mH coil, too big I think.
Has anyone had any experience on it?
Thanks
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Lightloopy

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Don't know about the bass but new panels will sound brighter if you were listening to dead panels. Also they will need some break in time if you have not factored that in yet. I am sure they will sound very nice when they settle in. Enjoy!
 

vimara

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Hello Lightloopy,
The panels were already installed in my old sequel II, they will be about a year old, so I think the problem or the difference is in the filters or in the bias current of the Sl3 that must be higher.
 

spkrdctr

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That is a HUGE fall off around 20 db. Something is wrong with your speakers. It would appear you are getting a very bass heavy response with almost no mids and highs (1K on up) at all. I would seriously look at the panels performance.
 
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Robert D

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Here is how my Prodigy panels looked from a test that Russ ran. He was going to recoat my panels but we decided not to and I just ordered new ones from ML. Mine are worn out.

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vimara

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Sorry, I hadn't made up for the pink noise.
the 76Hz peak that was not in my sequels, the 25 and 50 are from the room. These 76 seem from the resonance of the woofer. And the drop in the sharp end from 10K taking into account that the panels are new could be due to polarization or filter. In some old post I have read that modifying the filter to the ascent filter improves the sound, and considering that it has an additional 5 mf capacitor to reinforce the high end I think it would be a good option. At the moment I have lowered the braves switch to soften the peak, but I would like to solve it in a more correct way. Attachment measures with white noise. thanks.
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JonFo

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Stop horsing around and use an active xo for the bass only!
Preach!

Go further and go full active for both, you sound technical enough to deal with the complexities of a DSP (which pale next to getting a passive Xo right). A Driverack Venue360 would be great. But even a MiniDSP HD would do fine.
 

vimara

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Sure it is, but for me it makes no sense to have some magnificent Sugden 150W Class A Monophonics to be attacked by a DSP that converts the analog into digital and then back to analog. I wanted to get it without cheating. Although I recognize that it is the straightest path, I do not know if I am going to be comfortable with the idea of having one more digital step in my chain.
Thanks for your input.
 

Tosh

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Fix only what's broken (bass passive xo).
Stop making excuses, and use an ANALOG active xo on ONLY the bass!
 

vimara

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Good morning everyone from Spain, I have listened to you, I already have the biamplified Sl3 with an active xo.
I have a class A mono with the panel and a Krel Kst100 with the bass and an Amphion impact500 with direct input from dsp. As a DSP I am using a Driverack260 at the moment.
Impressions, doubts and queries.
The improvement in the clarity on the panel has been evident, there is still a progressive drop from 600hz to 250hz which is where I have the crossover, the voices are a bit cramped for this reason.
I already had the same problem with the passive xo, I thought it was the filter, but I see that they are the panels, they are new and at high frequencies I have no problems except for some peaks that I suppose will be resonances.
The problem with the lower part of the panel is that with the dsp I have to apply up to 10 db from 700hz to the crossover point to correct the drop, now everything sounds much better but I don't know if this is normal or I have a problem with the panels or their power supply.
With the bass, I honestly expected a much greater improvement, I have the crossover between 250hz and 50hz, I have corrected the nodes in the room a bit, but they still seem flabby and lacking in punch. I have soundcare feet and the bass enclosure is filled with wool.
I have delayed the panel 0.21 ms to equalize times.
My room measures 3.5 meters wide x 6 meters long by 2.70 high, I have the speakers 1 meter from the back wall and about 60cm from the sides.
I would appreciate advice.
The sequel II also appear in the image, which right now is not there so as not to cause resonances, but the sound was much better with the voices.
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JonFo

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there is still a progressive drop from 600hz to 250hz which is where I have the crossover, the voices are a bit cramped for this reason.
And this is why trying to use the original factory points / slopes is a waste of time. Even on a brand new SL3 panel I deployed in my center, the crossover is set for 340Hz 4th order (24dB/Octave), as any lower, and the panel lacks the output.
Here is the frequency response of a brand new SL3 panel with no XO in front of it:


Note how it drops like a rock at 230Hz, and yes there is a slight (3dB) tilt down starting at 700hz.
Heck, even crossing over at 400Hz would not be a bad idea, but the woofer would need to be changed out for one that is clean out to 800Hz and has a good impulse response (light cone). Meaning it will not play deep, so cross over to the subs at 80Hz.

The behavior in the sub-500Hz range will also require acoustically treating the room. Start by absorbing the rear wave of the speaker with absorption that is effective down to 200Hz (it will be thick and offset from the wall). Dipole cancellation is a real thing.

The DriveRack260 is a nice piece of gear, tons of flexibility with that one.
 

vimara

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thanks for your reply Jon,
Yes, I have noticed that trying to put the crossover higher the woofer does not work well, the voices get dirty and I have a lot of unwanted resonances, at the moment it is better option to lower to 250 with the panel and fix the curve with dsp, the type LR 48 cut, although very aggressive, I found it to be the cleanest in auditions.
Thank you for the recommendations.
 
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