Jump to content

Active Bi-Amping/Tri-Amping FAQ


Chris A
 Share

Recommended Posts

@Madman1Belles are 3 way or have you modified them to 2 way? If still 3 way you are using part of the passive crossover?

I would think you do not have to set a High Pass filter on the bass(LF), the natural roll off response of the bass bin horn will do that. Unless you are doing so intentionally to send even lower frequencies to a subwoofer. Similarly I would think a Low Pass filter on the HF is not needed either. Then as a starting point I would set the crossover frequency to be the same frequency and slope i.e. if the lowpass of the LF is set to 500hz 48db/oct, set the highpass of the HF to 500Hz 48db/oct. Again just as a starting point.

Jump in here @Chris A. Your expertise is much greater than mine. 

Link to comment
Share on other sites

@babadono Yes, using a alk super aa on the hf section and and Lf section is straight to the amp. those settings definitely helped, sounding better..actually much better. I know my rew measurements has lots of dips and peaks that need to be resolved. Should I run a new measurement and try to correct some of that every time I change a setting in crossovers? 

Link to comment
Share on other sites

Correct. Measure, adjust, repeat....measure,adjust, repeat

@Chris A will gladly help you get what you have as dialed in as possible...unless something has radically changed with Chris. His experience/expertise  is MUCH greater than mine...perhaps I am being overly presumptuous speaking for him.

Link to comment
Share on other sites

Honestly I’m just confusing myself with rew. I run the test get my graph, but really don’t know what to do from there to improve things with the eq. So many numbers, adjustments, levels and things I have no clue what they do. I try to find the ideal spot to flatten things out and match that. Sometimes it’ll let me and sometimes it tells me that the level is off by more than 10dbs. Guess It’ll just take a lot of trial and error to find out what I'm doing. 
 

reading thru another post from @Chris A on using rew he talks about a house curve, I found the spot for it in preferences but I don’t know where the house curve data comes from. I need to select a file  but where do I get that file from? 

Link to comment
Share on other sites

On 9/1/2021 at 8:11 PM, Madman1 said:

I've gotten the basic info loaded into the minidsp and have attempted to use rew....my lord that software is deep in the weeds for me. Anyway I can't get the sweep sent to the dsp  because it says my biquad input file isn't formatted correctly...yea like I know wth that means.

 

If exporting the settings from REW, I believe you need to export in the other format provided by REW.  First, you need to set the DSP crossover to "miniDSP", then "export to file" instead of "export to text" (highlighted in yellow on the right side of the figure below from REW's EQ facility).  You can change the DSP crossover type in Preferences, where you only have to do it once, instead of every time you take a measurement.

 

image.thumb.png.fb147c96328998a7887b2d2a11b1fa2a.png

 

Then the format of the data file from REW can be read directly into the miniDSP PC application,  instead of having to transfer the settings by hand.

 

Chris

Link to comment
Share on other sites

On 9/1/2021 at 8:11 PM, Madman1 said:

Here is a pic of my graph, looks pretty bad to me but I don't know how to fix it so...

If you send me a PM, I can return my email address to you, then you can send me your .mdat measurement file exported from REW. 

 

From that .mdat file, I can provide help, unlike screen shots.  One loudspeaker per measurement (not two), microphone in front of the loudspeaker by about 39.4 inches (1 metre), centered on the higher frequency horn, with plenty of absorption material on the floor between the loudspeaker and the microphone.  I use an old foam rubber mattress topper--laid out sideways, but blankets, quilts, comforters, lot of pillows, etc. will also work.

 

If you also send me the text file of your miniDSP settings (the one that you already have that's readable in text format), I can see what miniDSP settings you're using, and go from there.

 

Chris

 

 

Link to comment
Share on other sites

18 hours ago, Madman1 said:

Should I run a new measurement and try to correct some of that every time I change a setting in crossovers? 

In general, the process works like this:

  1. Clear all the PEQ, delay, gain, and crossover filter settings, then run a sweep (measurement) for each driver/horn, i.e., one measurement for the bass bin, one for the HF horn, etc.  Do not change the position of the microphone between measurements, anywhere.  Keep the microphone in the same place--don't move it--even by as little as 1/4 inch.
     
  2. Using that raw output measurements, decide where to put the crossover points, channel gains, delays, and initial PEQs (EQ filters).  Set these up within the miniDSP PC application and download them to the miniDSP crossover.
     
  3. Run another sweep (measurement) using all drivers turned on for the loudspeaker, and look at the results.  Adjust the settings and look at the results using REW. 
     
  4. Continue the process until the desired flatness of response is achieved.

Chris

Link to comment
Share on other sites

  • 3 weeks later...
On 9/2/2021 at 8:42 AM, Ray_pierrewit said:
I have the opportunity to purchase a well priced, functioning second hand Xilica DCP 3060. Knowing that I haven't currently got any subwoofers, do you consider this to be a step up from what I've got, or more of a lateral move? One day I intend on going 2 way with subwoofers, would the Xilica work for that as well? The Classe too?

 

If I purchase the Xilica, I will need to purchase XLR to RCA (balanced to unbalanced) cables, as the preamp and amp are RCA only. Do you see any problem with this?

 

Many thanks for any helpful input!

Daniel

 

So the seller of the DCP3060 has ghosted me. Too bad. I've found a newer Xilica UNO-U1616, does anyone have any input regarding this series of Xilica products? It's got the phoenix terminal block type connectors, 16 in 16 out, only programmable from the computer using Xilica's software. Any opinions?

 

Thanks

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

 Share

×
×
  • Create New...