The 6.8 Ohm series resistor and a 3.3 uF cap reduced the hiss coming from the 109dB sensitive 8 Ohm CD+horn to inaudible level. The digital level in HFD is now -2.5dB for the midrange, -4dB for the high freq driver and 0dB for the woofer. The series capacitor counteracts the sloping down response of the horn, so the digital filtering is almost flat in the passband of the tweeter, it sounds very good to my ears.
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quick question, Can a single 2 channel version (FA502) be configured to run a stereo pair of speakers?
It is considerably cheaper to buy a single 2 channel 500w plate than 2 x 2 channel 250w plates and bridge. It will also reduce the complexity and chance of issues arising there of.
Thanks.
Stuart
It is considerably cheaper to buy a single 2 channel 500w plate than 2 x 2 channel 250w plates and bridge. It will also reduce the complexity and chance of issues arising there of.
Thanks.
Stuart
FA251 is equipped with a high level input (picture attached). But such option is not given in modules as FA122. FA122 can be upgraded by adding an external small circuit for conversion of high level input to RCA outputs? Such module is available on the market or can be made? thanks!
Attachments
Some news about compression driver attenuation. The latest thing I tried is the "sine-cap" filtering, which consists a series resistor and a parallel inductor (a 8,2 Ohm resistor and a 0,1 mH inductor in my case), forming a high-pass filter (in reality, it's more like a shelf-filter) . We don't need a capacitor here. With a lot of attenutaion like a typical CD+horn requires, plus the sloping down response of the horn loading, this can be a very effective solution.
Of course a passive high-pass without series capacitor can't block DC for protection, that's the price we pay here.
I tried it because I don't like how (all) capacitors in the signal path colors the sound in their own way and I can say I like the result of the sine-cap filtering.
Critical listening is yet to come.
Of course a passive high-pass without series capacitor can't block DC for protection, that's the price we pay here.
I tried it because I don't like how (all) capacitors in the signal path colors the sound in their own way and I can say I like the result of the sine-cap filtering.
Critical listening is yet to come.
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Both sides of the connectivity panel are listed separately as modules at Hypex website. I guess they are interchangeable, if you can get one.
Hello!
I use 4 FusionAmp with LX521.4 speakers, 2 FA252 and 2 FA123
I found some information about different output gain level for each amplifier module.
Is it correct that i need to calculate based on MP-DSP documentation PDF and adjust some of amp modules regarding to others?
So for example if I take the baseline as NC122MP (i connected upper and lower mid here) and this is my reference zero level gain when setting up XO, and then I lower gains for tweeter NC100HF with 1.25 db, and also for subwoofers which are connected to NC252MP module - reduce them by 4.25 db
NC122MP 0
NC252MP 4.25
NC100HF 1.25
Andrii
I use 4 FusionAmp with LX521.4 speakers, 2 FA252 and 2 FA123
I found some information about different output gain level for each amplifier module.
Is it correct that i need to calculate based on MP-DSP documentation PDF and adjust some of amp modules regarding to others?
So for example if I take the baseline as NC122MP (i connected upper and lower mid here) and this is my reference zero level gain when setting up XO, and then I lower gains for tweeter NC100HF with 1.25 db, and also for subwoofers which are connected to NC252MP module - reduce them by 4.25 db
NC122MP 0
NC252MP 4.25
NC100HF 1.25
Andrii
Yes, measure each "way" independently, set eq, set xo, set gain and set delay (in HFD software, and download to FAs). Perhaps settings for minidsp 4x10HD can be used as guideline.
Andrii said " I use" - or are you just planning to use those? Where did you get HFD settings from? What measurement software and mic do you use?
I don't have LX521.4, but pretty much similar 4-way diy dipole speakers with minidsp 4x10HD. And two diy 3-way speakers with FA123.
Andrii said " I use" - or are you just planning to use those? Where did you get HFD settings from? What measurement software and mic do you use?
I don't have LX521.4, but pretty much similar 4-way diy dipole speakers with minidsp 4x10HD. And two diy 3-way speakers with FA123.
I build the speakers and amp setup few month ago
I got HFD settings from Linkwitz forum page, they are similar to miniDSP settings, but the problem was with gain levels.
Since miniDSP output same gain for each channel you need to recalculate and apply gain adjustments for combination of different FusionAmps.
I have UMIK-1 mic but I never did proper measurement, also I think this should be done using multimeter to measure exact voltage of the signal for each driver?
After I applied adjustments based on MP-DSP documentation the sound of speakers became very balanced, and REW measurements look nice in terms of freq and phase.
I would love to make exact measurements of the gain levels - so any input how to properly do it would be very helpfull
Measuring speaker out voltages works if you have same data with minidsp. Each driver has different sensitivity, so they need different voltage for same spl.
Seems like you have other dsp settings right, so the problem is to match FA123 and FA252 gain levels (by settings in HFD). You can do it roughly right as you planned in post #1 or by listening or with some mobile phone app, just make sure it uses dB(C) or dB(Z) weighting and look at spectrogram while playing white noise. Sine wave is too sensitive to room effect and mic position. If there are strange drops in spl at xo ranges, check polarity settings!
I warmly ask you to invest 100€ in a UMIK-1 from minidsp, and freeware RoomEQWizard! Room has very big influence below 500Hz, tuning to room response will make miracles to the sound. Just remember to save the "basic settings" first. It is really fun to learn to take and analyze different acoustic measurements, lots of info available!
Seems like you have other dsp settings right, so the problem is to match FA123 and FA252 gain levels (by settings in HFD). You can do it roughly right as you planned in post #1 or by listening or with some mobile phone app, just make sure it uses dB(C) or dB(Z) weighting and look at spectrogram while playing white noise. Sine wave is too sensitive to room effect and mic position. If there are strange drops in spl at xo ranges, check polarity settings!
I warmly ask you to invest 100€ in a UMIK-1 from minidsp, and freeware RoomEQWizard! Room has very big influence below 500Hz, tuning to room response will make miracles to the sound. Just remember to save the "basic settings" first. It is really fun to learn to take and analyze different acoustic measurements, lots of info available!
I do have the UMIK-1 and RME babyface pro card for making REW measurements
I just missing the proper guide how to make good measurements
https://www.minidsp.com/applications/acoustic-measurements/loudspeaker-measurements
https://www.audiosciencereview.com/...ents-spinoramas-with-rew-and-vituixcad.21860/
https://www.picotech.com/library/application-note/loudspeaker-measurement-technique
https://www.diyaudioandvideo.com/Tutorial/SpeakerResponseTesting/
There are manymany practical problems and tricks to get good measurements. Frequencies above 500Hz are easy indoors in normal room, below that it gets very difficult and one must use several techniques - nearfield, various distance, ground plane, MMM etc.. Everyone must learn his/her own practises... And we must accept to make errors, but we learn a lot from those in the end!
Feel free to send me personal mail, I can tell you more about "my way" with REW and multiway dipoles.
https://www.audiosciencereview.com/...ents-spinoramas-with-rew-and-vituixcad.21860/
https://www.picotech.com/library/application-note/loudspeaker-measurement-technique
https://www.diyaudioandvideo.com/Tutorial/SpeakerResponseTesting/
There are manymany practical problems and tricks to get good measurements. Frequencies above 500Hz are easy indoors in normal room, below that it gets very difficult and one must use several techniques - nearfield, various distance, ground plane, MMM etc.. Everyone must learn his/her own practises... And we must accept to make errors, but we learn a lot from those in the end!
Feel free to send me personal mail, I can tell you more about "my way" with REW and multiway dipoles.
