Khorns Time Alignment

[jcmusic]

Ok cool now when you say converters what exactly are you talking about? How did CD's get into this conversation?

[Chris A]

...I can also hear the effect of the acoustic absorbing panel (sideways bass trap) and it is very positive. Although its a bass trap, it somehow really helps out with the upper frequencies clarity.

 

The reason why bass traps work is because of the material used - most bass traps use Owens Corning 703, and it works very well as a broad-band absorber at high frequencies:

 

 

Here is a link to the full datasheet: http://buyinsulationproducts.com/files/38807120.pdf

Edited September 2, 2014 by Chris A

[Chris A]

I am not biased against digital at all. I listen to cd, sacd and like dsd and also make my own recordings in digital domain. However my analog chain sounds better than my digital chain. So unless the converters which I will put in between doesn't degrade anything I dont want to put them in. I dont want to fix some problems and introduce others.

 

Clearly the lowest cost approach that will solve your dilemma is a higher quality digital crossover than the miniDSP that you've apparently used.  I'm sure that the problems with trying all-pass networks far exceed the effective costs of a good digital crossover, otherwise Dennis (djk) wouldn't have been so blunt in answering the OP's question. Perhaps you should investigate more about djk's background and experience: I trust what he is saying.

 

My guess is that by the time that might be able to get some sort of custom passive network set up for your Khorns to correct for the large bass bin time delays, you will spend many times the amount of a single digital crossover unit, and you will still be left with problems--not the least of which is sensitivity to component heating.  I'm fairly sure that the major issue that djk is referring to is the highly varying input electrical reactance of the horns/drivers making the use of an all-pass filters prohibitive, and it probably won't sound very good to boot if you do manage to implement a network that corrects the time delays.

 

I would also guess is that more than one knowledgeable person has tried passive analog all-pass filters to correct for horn-loaded bass bin delays such as khorns (i.e., 4+ ms delays), but it didn't work very well.  YMMV.

Edited September 2, 2014 by Chris A

[kodomo]

Yes, it seems my solution is high quality active networks. It will have to wait a little more then...
 

 

 

The reason why bass traps work is because of the material used - most bass traps use Owens Corning 703, and it works very well as a broad-band absorber at high frequencies

Yes, they should be called broad band absorbers. These bass traps I put on top are actually not very efficient for the deep bass at all. However, some thicker and denser ones like vicoustic bass panels, I put in the opposite corners of the rooms are really helping with the bass too. 

 

Ok cool now when you say converters what exactly are you talking about? How did CD's get into this conversation?

 

It is not possible to listen to a cd without a converter as it is in digital domain I meant, if I was against digital I wouldn't bother listening from digital sources at all.

[jcmusic]

OK you were talking about a D/A digital to analog converters.

[jcmusic]

I am not using any DSP other than my PEQ's one for the mains the other for the Subs.

[kodomo]

http://www.deqx.com/product-hdpExII-install.php

 

This seems like a good option. I wish I had a chance to give it a listen. I already have two amps. I can use LM 219ia for the midrange, primaluna dialogue 2 for tweeters, and get a solid state for the bass section.

 

http://www.deqx.com/product-hdp4-overview.php

 

This one seems to give the option of adding your own converters as well. However the cost is going higher and higher.

 

 

I also wonder how 3 different amps work together. Does it have any downsides except the electricity bill!

[mark1101]

What I have learned from building active systems is that the processor is the heart..........your budget shoudl be generous here.  If you try to cheap out, the whole experience is ruined.  Ask me how I know. 

 

You need a good (expensive) processor.....trust me on this.

 

The other thing you need is I/O.......trust me on this also.  a 6 output device is not enough.  It will only do a stereo 3 way system, and no subs, and no spares.  You need at least 8 outputs........you will expand your setup and be in a pickle if you cheap out on your processor.......just my 2 cents.

 

If you are concerned about budget...........get passive networks and forget about building a good active system. 

[ClaudeJ1]

 

 

No they are not stock....

 Well, scratch that idea then.   

 

 

Still not a bad idea. It's more noticeable between the mid and tweeter, but getting them all lined up is certainly the best.

 

Bruce

 

I posed that same question to PWK in 1985. He said that time delay was more audible between the bass and mid, not the tweet and mid. Just sayin'

[Marvel]

He said that time delay was more audible between the bass and mid, not the tweet and mid. Just sayin'

I'm afraid that, as brilliant as PWK was,  I will have to disagree on this point. Yes, the delay is far greater, but I would still say less noticeable.

[mark1101]

It stands to reason where the longest delay exists is more than likely where you would notice the most.  In the case of the Khorn there is such an exaggerated delay between the bass horn and the mid, it's pretty easy to notice this sloppiness..........especially once you have heard it aligned.

 

I never aligned my Khorns but initially ran my MCM setup on passives (unaligned) experieinceing what I am saying here.

 

I think you might also notice the difference between mid horn and tweeter more if you replace either the squawker or tweeter horns and/or drivers with something other than stock Klipsch.  None of the replacement horns and drivers sound even close in timber and/or delivery to the stock Klispch parts..........and standout rather obviously to me...........such as using a wooden tractrix mid horn and K77 tweeter.......or stock midhorn/driver and CT-125 or baby cheeks tweeter.  These mismatches accentuate the differences in sound between the mid and tweeter.

[jcmusic]

Well I noticed a huge change in sound quality once the tweeters and mids were aligned. There is no more smearing of the sound everything became so much more clearer and cleaner, and the soundstage has gotten much larger.

Edited September 3, 2014 by canyonman

[Marvel]

My point is that the longer wavelengths at 400Hz can have greater delay and not be as obvious. Like having guitars out of tune at 400Hz (just under an A), compared to 5000Hz or so.

 

Bruce

[mark1101]

For me, the alignment is most noticable in the clarity of vocals, and tightness of bass.  My system is a 5 way, and alignment means a lot with bass and vocals coming from 3-4 drivers.

 

Getting back to Khorn..........another issue is the K55 has no LPF.  So it is "out of alignment" over a greater range than a filtered driver that dies at the crossover.

[Daan]

For what it's worth; my 2-way system is crossed over at 1Khz and when switching time-alignment in- or out the effect is obvious.

 

Try a good recorded drumsession and listen for the attack on the drum itself and the "punch" that follows. When those two arrive at the listenener's position at the same time it really sounds like a drum; fast, dry, explosive...you give it a name. When not aligned it just does not sound as a real drum anymore [my experience].

 

Also mentioned before;  it makes for that "wigglin' toes" effect.

[Chris A]

...None of the replacement horns and drivers sound even close in timbre and/or delivery to the stock Klipsch parts...and standout rather obviously to me..such as....or stock midhorn/driver and CT-125 or baby cheeks tweeter.  These mismatches accentuate the differences in sound between the mid and tweeter.

 

I agree that replacement drivers and horns don't sound the same, but then you seem to imply that they sound worse.  My impression of time aligning the Belle and correcting its FR using a few PEQs (that is, two PEQs on the bass bin, and one or two on the tweeter) alone changes the timbre of the loudspeaker fairly dramatically, and it makes it much better sounding, IMHO. 

 

Adding the Beyma CP25 made the loudspeaker sound much better than using the stock K77, especially after EQing the CP25 flat with two attenuating PEQs and running the crossover frequency down to 2.5 KHz from the 5-6 KHz area.  I found that the upper reaches of the Belle's midrange horn/driver really doesn't sound very good.  Pulling in the CP25 to cover this additional octave made a fairly big difference, IMHO.  My guess is that the polars of CP25 probably matches the polars of the midrange horn better at 2.5 KHz than at 6 KHz.  If you look at the polars, low distortion, and FR of the CP25, it looks a lot more solid than the K77--and it sounds a lot better, too. YMMV.

 

Once you make any change smooth out any significant peaking response of the drivers/horns and correct the time misalignments, the loudspeaker doesn't sound the same--it sounds much more neutral and lifelike (IMHO).

Edited September 3, 2014 by Chris A

[mark1101]

Chris,

 

I didn't mean to leave that impression (that it sounds worse).  But I do think that mixing tractrix mid horns with exponential tweeters, or vica versa does make things sound "disjointed" to me, or rather noticeably technically incorrect..........to my ears it creates distinctly different sounding "mids" and "highs".  it's easier to isolate each of them and poke at them.

 

You may find a smoother tweeter and better horns..........but please change them all and match them to one another and finish the job.    Don't change one tire on the car and pretend you can't tell there's a different type on there.

 

I used the CT-125 for a few months in lascalas, heresys, and cornwalls.  Initially you hear a big difference in smoothness and extention.  But the timber does not match the midhorn by a long shot, and the output is too low.  When I returned to the K77 the speaker sounded more technically correct to me.  Yes, teh K77 flaws came back, but overall sounded more "right" to me.

 

Digitizing and rebalancing without changing drivers and horns should give all the improvements you mention.  I agree with this approach.

[jcmusic]

Well I started with k77 tweeters then went to APT200's and now Fostex 90A's, there was an improvement with each. Now the Fostex are just night and day better than the other two!!!

[kodomo]

Mark, what do you use? What is your high quality multi output option. I want to learn about it, and learn about the price as well so I can start saving

[mark1101]

I use one Ashly Protea 4.8SP and one 3.6 SP.  I needed 10 outputs........so 2 identical processors.........just one has more I/O.  I have been using Ashly for 2-3 years now and i would buy them all over again.  They have been bulletproof and they sound right to me.