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01-30-2014

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Romy the Cat

Boston, MA
Posts 10,184
Joined on 05-28-2004

Post #:	1
Post ID:	20500
Reply to:	20500

First order filtration and design methods.

It was a conversation a few days back at one of UK forum:

http://www.audio-talk.co.uk/phpBB2/viewtopic.php?p=113989#113989

The unfortunates from the forum did not get the message. They with their Chinese digital crossovers, rock-n-roll brains, PA playbacks, necessity to kiss each other in ass and fear of own incompliance with genuineness too short-minded to get message but I thought the message is worth to me pinched again.

So, in my reply later I suggested: “think why I did not say that 4th order crossover did not work but instead I insisted that use of 4th order crossover indicate barbaric design techniques (most of times)”. I think it will be a good mental exercise for other to think about the answer to this question.

Rgs, Romy the Cat

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

01-31-2014

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noviygera

Chicago, IL
Posts 177
Joined on 06-12-2009

Post #:	2
Post ID:	20501
Reply to:	20500

4th order crossovers

I think this is an interesting topic. I have made experiments (with a digital dsp processor) in my system and tried 4th order crossovers. I did not like the sound at all. Trying to explain this sound signature is tricky but here is my interpretation of what I was hearing. With 1st order the sound was "stable" but not in regard to dispersion, on the contrary, there was noticeably more lobing going on as listening position shifted between channels. It was not "fragmented" in terms of continuity of overlapping regions between channels. With 4th order it was very much broken up and fragmented like a flickering unstable light bulb. For long term listening this was becoming more and more irritating and led me to conclude that 1st order gives a much more coherent presentation of the sound as a whole without this "paranoid" "anxious" disorder of the 4th order crossover.
Barbaric? This is a close enough description because what can one obtain using an ax and a sledgehammer! I think it much more difficult to sculp the sound with an "ax sledgehammer" approach to the crossover. And for most systems in the PA market the "ax/sledgehammer" is all that is needed but you can do a lot of damage to the sound with that approach, if every "blow" is not extremely calculated but then you still end up with a paranoid sound that is abruptly tossed between the channels.
One possible way out of the situation with 4th order "paranoid" tossing around is a coaxial approach. I have not tried it because I do not own a coaxial speaker but it seems that the "tossing" of the sound between channels would be minimized.

02-01-2014

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tuga

Posts 174
Joined on 12-26-2007

Post #:	3
Post ID:	20502
Reply to:	20500

The unsuccessful "quest for a better monitor"

Romy the Cat wrote:
It was a conversation a few days back at one of UK forum:

http://www.audio-talk.co.uk/phpBB2/viewtopic.php?p=113989#113989

The unfortunates from the forum did not get the message. They with their Chinese digital crossovers, rock-n-roll brains, PA playbacks, necessity to kiss each other in ass and fear of own incompliance with genuineness too short-minded to get message but I thought the message is worth to me pinched again.

So, in my reply later I suggested: “think why I did not say that 4th order crossover did not work but instead I insisted that use of 4th order crossover indicate barbaric design techniques (most of times)”. I think it will be a good mental exercise for other to think about the answer to this question.

Rgs, Romy the Cat

Romy,

On the subject of speaker design, I don't think you'll disagree if I say that your "quest for a better monitor" was unsuccessful.
You mentionaed at the time that the speakers should respect the following:

1) Perform correct in context of first order filter ,
2) Have correct tonal performance,
3) Do not require any frequency or impedance normalization,
4) Have low dynamic compression

What did you learn from the process and would have done differently?
Couldn't some of your requirements have been an obstacle to a more viable solution, possibly achieved by accepting a few compromises?
Do you feel that the design/conception of direct radiation speakers with box enclosures should obey to the same rules and requirements as horn speakers?

Cheers,
Ric

"Science draws the wave, poetry fills it with water" Teixeira Pascoaes

02-01-2014

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Romy the Cat

Boston, MA
Posts 10,184
Joined on 05-28-2004

Post #:	4
Post ID:	20503
Reply to:	20502

The same requirements.

tuga wrote:
Romy,

On the subject of speaker design, I don't think you'll disagree if I say that your "quest for a better monitor" was unsuccessful.
You mentionaed at the time that the speakers should respect the following:

1) Perform correct in context of first order filter ,
2) Have correct tonal performance,
3) Do not require any frequency or impedance normalization,
4) Have low dynamic compression

What did you learn from the process and would have done differently?
Couldn't some of your requirements have been an obstacle to a more viable solution, possibly achieved by accepting a few compromises?
Do you feel that the design/conception of direct radiation speakers with box enclosures should obey to the same rules and requirements as horn speakers?

An interesting question, Ric. My own build of “better” monitor was disastrous but I think it was not because my objectives or methods were wrong but because my lack of perseverance and focus. My better monitor was a side project, my desire to have Macondo “grand” experience from a small cold-operation package. I very much failed but it means nothing and I still feel that somebody who would focus on this will accomplish it and make it possible.

How do I think I would do it differently? I think would need to approach to it with a different level of seriousness and with higher degree of importance. I do not have this level of importance in me (because of multiple reasons) but I am very sure that with enough dedication to the course the things might be done.

If I were in the business to do it now then the requirements I would use the same.

"I wish I could score everything for horns." - Richard Wagner. "Our writing equipment takes part in the forming of our thoughts." - Friedrich Nietzsche

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