Crossovers Are Evil-

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DaveC113

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Re: Crossovers Are Evil-
« Reply #20 on: 22 Apr 2015, 07:49 pm »
All speaker designs are a set of compromises; you just need to pick the ones that best suit what you're looking for.

Exactly. The best single drivers do not make as much compromise but there are still laws of physics.

If I were putting a line level filter before the amp's inputs, I would use a capacitor (possibly a resistor as well).  This is actually changing the internal design of the amp by adding a resistor soldered to one of the tube socket pins and to ground.

To quote Dennis:  "Simply add a 100K , 1/2 watt resistor from pin #6 to ground on the KT-150 tube socket.  This will start a natural roll-off internally at 110 Hz with the signal down 3 dB at 60 Hz.  This will not change the the output phase angle like adding series caps on the input."


I did not think pin 6 is used?

http://www.tungsol.com/tungsol/specs/kt150-tung-sol.pdf

Usually there is an RC filter between the driver and output stage, here you could change either the R or C to effect a first order rolloff. So maybe he's talking about the grid leak resistor on pin 5?

lowtech

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Re: Crossovers Are Evil-
« Reply #21 on: 22 Apr 2015, 07:51 pm »
All speaker designs are a set of compromises; you just need to pick the ones that best suit what you're looking for.

The problem is that some of the compromises are orders of magnitude larger than others.  I guess it all depends on your frame of reference - exposure to a properly designed multi-way loudspeaker, for example.

If anyone hasn't noticed, the article published by the OP's URL is nonsense.   There are numerous fundamental misunderstanding made by the author.  It's probably not an issue who choose to believe what he's attempting to convey, though.

pstrisik

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Re: Crossovers Are Evil-
« Reply #22 on: 22 Apr 2015, 07:53 pm »

I did not think pin 6 is used?

http://www.tungsol.com/tungsol/specs/kt150-tung-sol.pdf

You are correct.  He later corrected himself:  "Your amp may not have a connection on pin 6 of the output tubes.  If that is the case connect the 100K, 1/2 watt resistor from pin 5 of the output tube socket to ground."

I didn't figure anyone would read it at that level to catch it.  I didn't edit his original statement to keep from making it complicated.  Oh well...   can't get anything by this group!

You may be correct about the design rationale, but it quickly gets beyond my comprehension.

BTW, not that it matters, the amp is called an Inspire KT-150 and originally came with those power tubes.  It will run many pentodes though.  I currently run it with 6V6's.



rajacat

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Re: Crossovers Are Evil-
« Reply #23 on: 22 Apr 2015, 07:59 pm »
Do any of Louis's designs capture the scale and impact of a symphony orchestra at an appropriate volume level?

macrojack

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Re: Crossovers Are Evil-
« Reply #24 on: 22 Apr 2015, 08:00 pm »
As I understand it, anything inserted in the signal path will influence the sound coming from your speakers. By the logic used in the original post, that makes amplifiers evil.

bladesmith

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Re: Crossovers Are Evil-
« Reply #25 on: 22 Apr 2015, 08:05 pm »
As I understand it, anything inserted in the signal path will influence the sound coming from your speakers. By the logic used in the original post, that makes amplifiers evil.

Technically YOU are correct.....!

 :lol: :lol: :lol:

seikosha

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Re: Crossovers Are Evil-
« Reply #26 on: 22 Apr 2015, 08:07 pm »
Do any of Louis's designs capture the scale and impact of a symphony orchestra at an appropriate volume level?

I doubt it, but then in my whole life, I've only heard one speaker that came close and that was the Infinity IRS about 30 years ago.  They were close, but not quite there.

woodsyi

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Re: Crossovers Are Evil-
« Reply #27 on: 22 Apr 2015, 08:08 pm »
My solution will be to follow the great tip offered by my amplifier's designer, Dennis Had.  He told me how to insert a single resistor in each channel - within the amp itself - that would slowly roll off the signal below 110db.  This will allow me to make better use of mid-bass woofers (50hz up to 200hz) and subwoofers (below 50hz).  More on this project to follow in a bit.

This was the part I was scratching my head about.  I would need a real quick roll off from 110 db. :lol:

DaveC113

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Re: Crossovers Are Evil-
« Reply #28 on: 22 Apr 2015, 08:17 pm »
I'm using a digital high pass crossover set to 50 Hz with a 24 dB slope on my Omegas, for higher SPLs and bass-heavy music it's amazing. It basically eliminates excess excursion caused by trying to reproduce frequencies under the tuning frequency of the bass reflex cabinet. We are getting to a point where DSP based digital crossovers are very transparent and often a better choice vs traditional passive crossovers.

pstrisik, I think it's worth trying to make a crossover out of the interstage coupling cap and grid leak resistor, I have had the parts to do the same with my gear but all you will get is a 6 dB/octave slope so some undesirable low frequency information will still make it to the Omega drivers, but it'll be less and is well worth a shot IMO...


a.wayne

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Re: Crossovers Are Evil-
« Reply #29 on: 22 Apr 2015, 08:18 pm »
Check out any current Omega and you might change your mind.


Havent heard Omega's , did they change the laws of physics..?  :D, IYO, do they sound better than Magico? Wilson? ML, MG20.7 , Vandies, we maybe looking for something different with respects to sonics, I'm sure they rock your boat,  not questioning your enjoyment , the physics is not debatable thou and distortion increases by a factor of 10 with every .10MM of excursion ( If old memory serves me :)  ) ..



Regards...

rajacat

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Re: Crossovers Are Evil-
« Reply #30 on: 22 Apr 2015, 08:22 pm »
I doubt it, but then in my whole life, I've only heard one speaker that came close and that was the Infinity IRS about 30 years ago.  They were close, but not quite there.
So are you saying that a 7" single driver can do justice to a full orchestra as well as a pair of Sound Lab U-1PXs'?
http://www.soundlab-speakers.com/ultimate-px.html

Not trying to belabor the point but at some point you have to make compromises.

DaveC113

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Re: Crossovers Are Evil-
« Reply #31 on: 22 Apr 2015, 08:30 pm »

Havent heard Omega's , did they change the laws of physics..?  :D, IYO, do they sound better than Magico? Wilson? ML, MG20.7 , we maybe looking for something different with respects to sonics, the physics is not debatable thou...



Regards...

Agreed and probably not. BUT you are comparing some of the most expensive speakers in the world to a line of speakers that tops out around $3k.

Every speaker makes compromises and the degree of compromise is often determined by cost. Omega offers a speaker with much less compromise for the money spent vs most any other speaker.

Also, the more expensive multi-way speakers generally beat Omegas in terms of SPL output abilities and macro-dynamics, which are not everyone's top priorities. In a small room, listening nearfield at reasonable volumes the list of speakers that will beat Omega shrink quite a bit and DO NOT include anything on your list, imo.

seikosha

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Re: Crossovers Are Evil-
« Reply #32 on: 22 Apr 2015, 08:37 pm »
So are you saying that a 7" single driver can do justice to a full orchestra as well as a pair of Sound Lab U-1PXs'?
http://www.soundlab-speakers.com/ultimate-px.html

Not trying to belabor the point but at some point you have to make compromises.

No, I'm saying that not even the monster Infinity IRS could not quite capture what you hear in a symphony hall when a full orchestra hits the "fff" crescendos.  If the Infinity's couldn't do it, I wouldn't think that any of the Omegas could either let alone just about any speaker in existence.


RDavidson

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Re: Crossovers Are Evil-
« Reply #33 on: 22 Apr 2015, 08:42 pm »
It depends on room size and listening distance.

rajacat

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Re: Crossovers Are Evil-
« Reply #34 on: 22 Apr 2015, 08:57 pm »
No, I'm saying that not even the monster Infinity IRS could not quite capture what you hear in a symphony hall when a full orchestra hits the "fff" crescendos.  If the Infinity's couldn't do it, I wouldn't think that any of the Omegas could either let alone just about any speaker in existence.
Would you grant me the point that the Sound Labs would do a better job with large orchestras than any single driver?

Canada Rob

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Re: Crossovers Are Evil-
« Reply #35 on: 22 Apr 2015, 09:01 pm »

Havent heard Omega's
In the USA Omegas can be bought on a 30 day trial.

ZLS

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Re: Crossovers Are Evil-
« Reply #36 on: 22 Apr 2015, 09:15 pm »
It depends on room size and listening distance.

    And there we get to the crux of it. 

    There are compromises, and there is the recognition of reality.

    As great as the Omega Speakers are, they cannot circumvent the laws of Physics. 

    It can be said that a large part of their greatness is they don't try to defy Physics. 

    How large of a standing wave can the average listening room really handle? 

    How low of a bass wave is physically possible to reproduce before it starts creating more problems then it solves? 

    The first thing new owners of Omega Speakers report is how clear they sound; sometimes this manifests as a soundstage,

    other times as sound layering. 

    Can a 4 1/2 inch driver play as loud a four drivers; obviously not.

    The point is it doesn't try to, and therein lies the magic. 

pstrisik

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Re: Crossovers Are Evil-
« Reply #37 on: 22 Apr 2015, 09:38 pm »
    And there we get to the crux of it. 

    There are compromises, and there is the recognition of reality.

    As great as the Omega Speakers are, they cannot circumvent the laws of Physics. 

    It can be said that a large part of their greatness is they don't try to defy Physics. 

    How large of a standing wave can the average listening room really handle? 

    How low of a bass wave is physically possible to reproduce before it starts creating more problems then it solves? 

    The first thing new owners of Omega Speakers report is how clear they sound; sometimes this manifests as a soundstage,

    other times as sound layering. 

    Can a 4 1/2 inch driver play as loud a four drivers; obviously not.

    The point is it doesn't try to, and therein lies the magic.

Agree (I think). 

Volume level is not the only criteria.  There are many, many speakers that will play louder than omegas.   Omegas will likely sound better than most multiway speakers at lower volumes.  And they will very likely excel at imaging over most multiways, certainly those at comparable cost.  IMO, if high volume is a primary requirement, single drivers may not be the best choice.


pstrisik

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Re: Crossovers Are Evil-
« Reply #38 on: 22 Apr 2015, 09:45 pm »
This was the part I was scratching my head about.  I would need a real quick roll off from 110 db. :lol:

Thanks...  definitely sloppy proofreading on my part!  I'll edit that post.

I'm using a digital high pass crossover set to 50 Hz with a 24 dB slope on my Omegas, for higher SPLs and bass-heavy music it's amazing. It basically eliminates excess excursion caused by trying to reproduce frequencies under the tuning frequency of the bass reflex cabinet. We are getting to a point where DSP based digital crossovers are very transparent and often a better choice vs traditional passive crossovers.

pstrisik, I think it's worth trying to make a crossover out of the interstage coupling cap and grid leak resistor, I have had the parts to do the same with my gear but all you will get is a 6 dB/octave slope so some undesirable low frequency information will still make it to the Omega drivers, but it'll be less and is well worth a shot IMO...

I realize it is a slow roll off, but it will help with minimal cost in $ and in side effects that might negatively affect the sound.

Curious, what is the digital xover you are using?  And do you have a DAC upstream from it or do you use digital inputs at the xover?  I'm open to the possibility of using one if it would work out for me.  My biggest concern is having to substitute the incorporated DAC for the one I have already chosen.

Thanks..........


seikosha

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Re: Crossovers Are Evil-
« Reply #39 on: 22 Apr 2015, 11:15 pm »
Would you grant me the point that the Sound Labs would do a better job with large orchestras than any single driver?

Yes, I'd certainly expect them to.