Behringer DCX2496 digital X-over - Page 259

Pano · 5th February 2010, 01:22 PM

Legis, from what you say it would seem that the problem is in the analog input section.
If the auto-align and digital inputs work, that would point a finger at the analog input.
Have your tech check there first.

Legis · 5th February 2010, 01:55 PM

Quote:

Originally Posted by pos

Do you think it is due to the new dac or the new opamps? Did you also change some caps in that one?

I have no idea which one, I got them bot changed at the same time...

It's not that big, it's just bigger than before. Woofer jumps a little.

I'm thinking could the thump be too much fot a ribbon tweeter without a passive crossover? It is not loud but it consist of bass signal, because the woofer jumps a little. Could it harm the ribbon?

Panomaniac, I have them now workin' ok, just 1 hour ago installed them. The man said that some of the foils were torn of and that caused the B channel to go mute.

I ran RMAA just a minute ago, I think the improvement are pretty nonexistent with new DAC and op-amps, what comes to measurements. The dynamic range and noise floor has dropped approx 2dB's because of the slightly higher gain (RMAA's gain meter goes higher, very close to +/- 0dB, before it was something like -1,5 - 1,1 dB)

What comes to the character of the sound, the sound is very pure and clear. I have been running Zero DAC and Maverick Tube Magic D1 connected straight to the amps for this time the DCXs were gone. DCX does not hinder the sound in any way, compred to those DACs. Like I said before, when I took DCXs out of the signal path when I got them modded, I could tell a little imprevement in the sound after DCX were gone... So some, although quite small, purification has happened in the sound.

Pano · 5th February 2010, 02:19 PM

Cool!

Legis · 5th February 2010, 02:44 PM

Quote:

Originally Posted by Legis

The dynamic range and noise floor has dropped approx 2dB's because of the slightly higher gain (RMAA's gain meter goes higher, very close to +/- 0dB, before it was something like -1,5 - 1,1 dB)

Ops, I ment of course that noise floor has dropped and DR has risen, thus both have improved.

Legis · 5th February 2010, 05:07 PM

Since this is a DCX related question and many DCX users face the same situation, I might as well as it on this thread.

Have you put any hi-pass filter for your tweeter while using active crossover like DCX? Which is the best way to make a passive crossover to tweeter/ribbon. A cap in the speaker cable rises the capasitance quite heavy if i want to use lower hi-pass like 1000hz.

Mainly I would like to have a hi-pass for ribbons, since their impedance drops near zero at low freqs. Thjis could burn both ribbons and amp.

AndrewT · 6th February 2010, 09:49 AM

I would prefer to see a cap protecting the tweeters from DC and excessive LF signal.

This passive filter can be adjusted to the required crossover frequency.
However it will not fall @ -6dB/octave due to the varying impedance presented by the driver.

Now you can add on an active filter to bring up the required filter pole and Q.

If you wanted Butterworth 4pole then a 3pole Q=1 active filter will add to the single pole Q=0.7 passive filter to give ~4pole Q=0.7 total filter, with an error in the 4pole characteristic due to driver impedance variation.

Now you need to look at the driver's acoustic roll off. This has to be added to the active and passive filters you have.
The result is not a 4pole Butterworth. It will take a quite a bit of time and expertise to achieve the target filter.
The DCX should make this process much easier to implement than soldering on alternative components.

Legis · 10:45 AM

Is this a good choice for passive level controlling after DCX, competitor for seletronic cotroller jan Jan's system? Is has 8 channel control, which I would need since I have two DCXs each driving 4-way channel.

It's name is the SPL Volume 8. Looks quite nice.

Description: Sound Performance Lab

and heres a review in Germany: http://www.spl.info/fileadmin/user_u...at_volumes.pdf

Is there a cheaper 8ch controller around? It could be whole passive controller also, just eight potentiometers put in to a box without any transformer.

edit: would some Behringer's mixer work?

Legis · 6th February 2010, 11:03 AM

Quote:

Originally Posted by AndrewT

I would prefer to see a cap protecting the tweeters from DC and excessive LF signal.

This passive filter can be adjusted to the required crossover frequency.
However it will not fall @ -6dB/octave due to the varying impedance presented by the driver.

Now you can add on an active filter to bring up the required filter pole and Q.

If you wanted Butterworth 4pole then a 3pole Q=1 active filter will add to the single pole Q=0.7 passive filter to give ~4pole Q=0.7 total filter, with an error in the 4pole characteristic due to driver impedance variation.

Now you need to look at the driver's acoustic roll off. This has to be added to the active and passive filters you have.
The result is not a 4pole Butterworth. It will take a quite a bit of time and expertise to achieve the target filter.
The DCX should make this process much easier to implement than soldering on alternative components.

Hi Andrew, I'm going to use that hi-pass filter only for ribboons' and amplifier's protection, the real hi-pass will be done with DCX. The passive hi-pass could be set to 1000hz and the real hi-pass to 3000Hz with DCX.

Because DCX thump when powering it up/-off, I think it would be wise to be safe than sorry with burn ribbons,m which are quite pricey (Fountek NeoCD3.0)

I'm not sure if i need any hi-pass filter I I could mod my DCX's starting regime so it would not thump at the power up/-off. Is there such a mod?

Theres still a possibilty that I might by mistake turn off the hi-pass filter of the ribbons.

Brett · 6th February 2010, 11:08 AM

Quote:

Originally Posted by Legis

Because DCX thump when powering it up/-off, I think it would be wise to be safe than sorry with burn ribbons,m which are quite pricey (Fountek NeoCD3.0)

The power consumption is trivial. Leave the bugger ON all the time, so no thumps.

Legis · 11:38 AM

Concerning the passive level control, this is very very interesting. XLR input and outputs, whole passive system, cheap.

One could add these as many as one needs.

TC ELECTRONIC LEVEL PILOT - Thomann Verkkokauppa

Is there possibly a better solution than this? I half-ready to order them

Information on manufacturer's website: http://www.tcelectronic.com/LevelPilot.asp

Edit: Here's another one, but not quite as good looking as TC electronics and does not have XLR outputs but instead jack outputs: http://www.thomann.de/fi/sm_pro_audio_nano_patch.htm

5th February 2010, 01:22 PM	#2581
Pano diyAudio Moderator Join Date: Oct 2004 Location: North Carolina Blog Entries: 4	Legis, from what you say it would seem that the problem is in the analog input section. If the auto-align and digital inputs work, that would point a finger at the analog input. Have your tech check there first. __________________ Take the Speaker Voltage Test!

6th February 2010, 10:41 AM	#2587
Legis diyAudio Member Join Date: Dec 2009	Is this a good choice for passive level controlling after DCX, competitor for seletronic cotroller jan Jan's system? Is has 8 channel control, which I would need since I have two DCXs each driving 4-way channel. It's name is the SPL Volume 8. Looks quite nice. Description: Sound Performance Lab and heres a review in Germany: http://www.spl.info/fileadmin/user_u...at_volumes.pdf Is there a cheaper 8ch controller around? It could be whole passive controller also, just eight potentiometers put in to a box without any transformer. edit: would some Behringer's mixer work? Last edited by Legis; 6th February 2010 at 10:45 AM.

6th February 2010, 11:09 AM	#2590
Legis diyAudio Member Join Date: Dec 2009	Concerning the passive level control, this is very very interesting. XLR input and outputs, whole passive system, cheap. One could add these as many as one needs. TC ELECTRONIC LEVEL PILOT - Thomann Verkkokauppa Is there possibly a better solution than this? I half-ready to order them Information on manufacturer's website: http://www.tcelectronic.com/LevelPilot.asp Edit: Here's another one, but not quite as good looking as TC electronics and does not have XLR outputs but instead jack outputs: http://www.thomann.de/fi/sm_pro_audio_nano_patch.htm Last edited by Legis; 6th February 2010 at 11:38 AM.

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5th February 2010, 02:19 PM	#2583
Pano diyAudio Moderator Join Date: Oct 2004 Location: North Carolina Blog Entries: 4	Cool!

5th February 2010, 05:07 PM	#2585
Legis diyAudio Member Join Date: Dec 2009	Since this is a DCX related question and many DCX users face the same situation, I might as well as it on this thread. Have you put any hi-pass filter for your tweeter while using active crossover like DCX? Which is the best way to make a passive crossover to tweeter/ribbon. A cap in the speaker cable rises the capasitance quite heavy if i want to use lower hi-pass like 1000hz. Mainly I would like to have a hi-pass for ribbons, since their impedance drops near zero at low freqs. Thjis could burn both ribbons and amp.

6th February 2010, 09:49 AM	#2586
AndrewT diyAudio Member Join Date: Jul 2004 Location: Scottish Borders	I would prefer to see a cap protecting the tweeters from DC and excessive LF signal. This passive filter can be adjusted to the required crossover frequency. However it will not fall @ -6dB/octave due to the varying impedance presented by the driver. Now you can add on an active filter to bring up the required filter pole and Q. If you wanted Butterworth 4pole then a 3pole Q=1 active filter will add to the single pole Q=0.7 passive filter to give ~4pole Q=0.7 total filter, with an error in the 4pole characteristic due to driver impedance variation. Now you need to look at the driver's acoustic roll off. This has to be added to the active and passive filters you have. The result is not a 4pole Butterworth. It will take a quite a bit of time and expertise to achieve the target filter. The DCX should make this process much easier to implement than soldering on alternative components.