Example (or starter) filter configuration file for a Hypex Fa123

[maxime.levesque]

I just finisehd building a pair of 3 way speakers based on this Troel Gravesen design http://www.troelsgravesen.dk/SBA-941.htm

and I got a pair of Hypex Fa123 to power them.

I am getting acquainted with the Hypex filter design software, and I realize there are many ways to do achieve the crosovers prescribed by Troel, i.e.: 580 Hz and 2700 Hz.

My learning curve for designing filters with the Hypex software would be greatly reduced if I could download a functioning configuration file for 3 channels on the Fa123 (or other Fusion 3 channel amps).

I could use it to see what a good configuration looks like, and perhaps start with it, and alter a few parameters to obtain crossovers at 580Hz and 2700Hz.

Anyone willing to post their configuration, or point to downloadable ones ?

Thanks !

 

[headshake]

SEAS The Art Of Sound Perfection

THE ART OF SOUND PERFECTION BY SEAS

www.seas.no

Here are SEAS FAXXX files for a kit. There are 3 configs.

Be sure to read in the manual how to convert filters into the biquads. For example, I had to use 4 biquads to make a LR8 on each driver.

 

[maxime.levesque]

SEAS The Art Of Sound Perfection

THE ART OF SOUND PERFECTION BY SEAS

www.seas.no

Here are SEAS FAXXX files for a kit. There are 3 configs.

Be sure to read in the manual how to convert filters into the biquads. For example, I had to use 4 biquads to make a LR8 on each driver.

@headshake thanks for the recommendation, I downloaded the config and opend it with the filter design software, it's a great example !

Now I have to decide which kinds of filters I will try first, there are so many to choose from !

Out of curiosity, what went into your decision process when you chose to use LR8, as opposed to Butterworth for example ?

 

[Juhazi]

Ehem,

1) first thing to do is to take measurements of your speaker's drivers separately, without any xo. Study off-axis dispersion and distortion, to find out best crossover frequencies
2) equalize each driver to be flat at least one octave beyond propable xo frequency
3) start with symmetric LR4 settings, adjust gain and delays to get nice response
4) measure the whole system again, look at response, dispersion smoothness and distortion. listen to your favourite music.
5) measure response at listening spot, perhaps you must set some room-EQ in bass range and to set tonal balance throughout the range. Save as preset 1
6) when you are happy, try different xo topology (repeat stages 3-5, save as preset 2). Listen and compare to preset 1
7) repeat 6), save as preset 3 and listen, compare
8) repeat 7), save as preset 3 etc. save preset 4. Listen and compare to preset 1,2,3...

Have fun!

 

[headshake]

it's a great example !

Cheers! Yeah, lots of kung fu in that XO. I find it more aggressive than what I would do. It made me second guess how I approach things. And the use of shelf filters was something I ignored.

what went into your decision process when you chose to use LR8

Right now, just a baffle sim and the XO slope for the passive kit designed by the speaker manufacturer. It is for a tiny coax. I am in the process of verifying it now as Juhazi describes.

I'd add to his number 4, that you should invert the tweeter, look at the response and try a range of delays. It can show if you wired things properly and if you have the delay right.

 

[maxime.levesque]

Ehem,

1) first thing to do is to take measurements of your speaker's drivers separately, without any xo. Study off-axis dispersion and distortion, to find out best crossover frequencies
2) equalize each driver to be flat at least one octave beyond propable xo frequency
3) start with symmetric LR4 settings, adjust gain and delays to get nice response
4) measure the whole system again, look at response, dispersion smoothness and distortion. listen to your favourite music.
5) measure response at listening spot, perhaps you must set some room-EQ in bass range and to set tonal balance throughout the range. Save as preset 1
6) when you are happy, try different xo topology (repeat stages 3-5, save as preset 2). Listen and compare to preset 1
7) repeat 6), save as preset 3 and listen, compare
8) repeat 7), save as preset 3 etc. save preset 4. Listen and compare to preset 1,2,3...

Have fun!

Is there a danger of busting the tweeters if I take measurements of all 3 drivers before putting hipass and lowpass filters ?

I did add capacitor to protect the tweeters, so I suppose it is safe, but I've read that tweeters can be busted if they are sent sound signals that are too low....


Would it be problematic to start by configuring crossovers filters at 580 Hz and 2700 Hz, since the encosures are based on Trown Graveson's plans that prescribes such crossover points ?

 

[Juhazi]

maxime,
To prevent tweeter damage, adjust sweep range for the measurement to eg. 800-22000Hz (easy with REW and should be possible with other software too). Gravesen's xo is a very good starting point to imitate.

I install a "highpass" protective capacitor in series with the tweeter too. People do make mistakes....

headshake added good advise too, for symmetric xo. I do "wrong polarity test" too, it makes delay adjustment easier.

All this takes some time to digest. One must gather pieces of info from many different sources, but some info is plain wrong or easy to misunderstand. With dsp it is mostly time that gets wasted, but I have destroyed some tweeters yes... One should not start with expensive drivers!