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A time-aligned top end - Part II


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The K510 starts unloading below 500hz so it wouldn't have gone lower without EQ.

If I'm remembering correctly, I believe the K510 loses vertical pattern control at about 2kHz and at about 1kHz in the horizontal. I wonder if the lascala doesn't start clover-leafing above 500Hz.

When setting up a Jubelle I borrowed Roy's settings for the K510/K69 and noticed a rather dramatic rise in the HF response, that Roy says is to account for the wider polars down low and the narrower polars above ~7kHz due to the 2" throat (phase plug response). This speaker was being used for a center channel so I figured the off-axis energy would be less dominant and reduced the boost (flatter on-axis)...but after listening we ended up with most of the boost back in to keep it timbre matched to the Jubilee. I've always been surprised by this, but have had the same experiences on several different horns.

Would you have any interest in capturing an impulse response at your listening position? If we both use the same mic, we could make a pretty good comparison on relative voicing. I'd love to know if we're aiming for tbe same sound, or if it's just a difference in preference? Doesn't absorption get less effective as you go lower in frequency?

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Well since you've already got an amp, you could always try it out in mono (1 channel for LF and 1 for HF). In my opinion, if you like loud, then pro amps are good, but if you're wanting clean and quiet then I might go other routes...either higher quality lower power pro amps, or a home audio amp...

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I may have an unwarranted bias against the P-Audio driver. I think I heard talk about them being inconsistent.

Al K.

Al, I can't speak to manufacture consistency, but I think I know where the bias comes from. I spent a good bit of time this weekend messing around with my P. Audio drivers. The bottom line for a 2 way setup is that you have to EQ the daylights out of the top end to make them sound really good. I know Roy's numbers for the Jub and the K402 can show you how much EQ they need. That driver is really hard pressed for a two way operation on the top end. I have been happy with mine, but would really like to find a reasonably priced driver that can provide a better response on the high end. I am very hopeful for the Faital Pro driver.

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I spent a good bit of time this weekend messing around with my P. Audio drivers. The bottom line for a 2 way setup is that you have to EQ the daylights out of the top end to make them sound really good. I know Roy's numbers for the Jub and the K402 can show you how much EQ they need.


Are you sure it's not the EQ required by the horn, rather than the driver? It's been mentioned on this forum many times that CD horns like the K402 and K510 always need lots of EQ to give a relatively flat frequency response.
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Are you sure it's not the EQ required by the horn, rather than the driver? It's been mentioned on this forum many times that CD horns like the K402 and K510 always need lots of EQ to give a relatively flat frequency response.

That may certainly be an issue. But, if you start by looking at the published FR of the drivers, you will see it rolls off quite a bit above 10kHz and IIRC starts a drop even earlier at 6kHz. Now, that may be due to the horn used in testing, but all I know is that it needs EQ. It would be interesting to test the driver in one of the new elliptical horns.

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http://www.jblpro.com/pub/components/2447.pdf

Look at the plane-wave tube response. This is what the driver puts into the horn.

Look at the combined response of the horn and driver.

The plane-wave response plus the Di of the horn equals the combined response of the driver on the horn.

http://www.jblpro.com/pub/obsolete/23525354.pdf

Compare PWT vs on horn reponse on an old style radial horn.

http://alteclansingunofficial.nlenet.net/publications/techletters/TL_231.pdf

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I may have an unwarranted bias against the P-Audio driver. I think I heard talk about them being inconsistent.

Al K.

Al, I can't speak to manufacture consistency, but I think I know where the bias comes from. I spent a good bit of time this weekend messing around with my P. Audio drivers. The bottom line for a 2 way setup is that you have to EQ the daylights out of the top end to make them sound really good. I know Roy's numbers for the Jub and the K402 can show you how much EQ they need. That driver is really hard pressed for a two way operation on the top end. I have been happy with mine, but would really like to find a reasonably priced driver that can provide a better response on the high end. I am very hopeful for the Faital Pro driver.

Rudy remember the K69-A is the tweeter driver in several of Klipsch's commercial offerings and isn't hard pressed in this application. I've shown this before in past threads on this subject but the EQ-ing is mostly the requirement due to the K402/K510 constant coverage design and is simply a reduction in drive level as frequency decreases with very little gain used at the top end in the active systems.

I'm not claiming that the K69-A or equilivant versions are perfect by any means but some issues you are having could be caused by the type of horn you have it mated to. If I remember correctly the horn your using has a diffraction slot style throat design and this probably isn't an optimum design for 2-way operation.

I don't believe many here really understand how unique the K402 and K510 are when it comes to polar control (within their design limits) and this having been acheived without a diffraction slot and the negative effects these other designs exhibit.! I really don't know of any horns available that are better suited for 2-way operation than these two horns from Klipsch. Why should a desirable design goal be frequency independent polar control in a loudspeaker? Lack of polar control in a loudspeaker leads to colorations that are frequency dependent and thus more room dependent/listener location dependent for optimum performance.

There are some very good driver options available today for 2-way operation besides the K69A but all I know of are more expensive. The TAD TD4002 for example has better clarity that I believe most anyone could hear when directly compared but when driver cost are taken into account many will think the K69A is a real bargain.

mike tn

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mike, you certainly know tons more about the subject than I do. I have not taken the horn into account, primarily due to lack of knowledge, but am always glad to discuss these issues with you guys so I can learn. In studying the suggested EQ settings, it is easy to see what the goal was. That is to reduce the drive level as the frequency decreases. In effect, it lowers the response to match what the driver can do above 12 or 13kHz. I actually tried to do that in my system to see how it would sound, but my Ashly crossover will not allow to set a low shelf above 2kHz. It would have been a great way to EQ the driver since it is much more efficient than the bass bin.

Yes, the P. Audio horn I am using has a diffraction slot. I might try to get a hold of a K510 and see how it sounds.

Mind you, I am not knocking the K69, particularly since it is one of few reasonably priced drivers that I found to use in a two way setup. I don't know if the Faital Pro will be any better, but at least on paper its individual FR is better in the high end....or am I not understanding this correctly?

Here is a closeup of my P. Audio CD horn.

post-10337-13819636266166_thumb.jpg

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mike, one other thing. I know you are talking about the 'K69' and my experience is with the P. Audio BM-D750.....I'm assuming they are operationally the same based on various posts on the subject. I picked the P. Audio horn since it should be a good fit with that driver. That combination is mentioned in the literature. Two drivers are suggested for that horn and one of them is the BM-D750. If you look at the response curve on the literature, you can see the two rolloff points around 6kHz and 13kHz. http://www.paudiothailand.com/pdf/products/PH-4525.pdf

It would be interesting to compare my horn and the K510.

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I don't know if the Faital Pro will be any better, but at least on paper its individual FR is better in the high end....or am I not understanding this correctly?

Since we don't know the DI of the horns that the Faital Pro drivers are being measured on, we don't really know how the driver is performing on paper. This is where plane-wave tube responses become very useful for comparing drivers....it's essentially a resistive acoustic load (perfect horn) with no DI. I'm writing from my phone, but check out the datasheet for the Selenium D220i. They show both the plane wave tube response and the on-axis frequency response on a horn that beams like crazy...note the polar response charts they show. I believe a straight up tractrix area expansion should have about 8dB of DI at the higher frequencies.

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Well since you've already got an amp, you could always try it out in mono (1 channel for LF and 1 for HF). In my opinion, if you like loud, then pro amps are good, but if you're wanting clean and quiet then I might go other routes...either higher quality lower power pro amps, or a home audio amp...

Mike, in order not to hijack this thead, I started a new topic on the amp question here: http://forums.klipsch.com/forums/p/144579/1481264.aspx#1481264

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Mind you, I am not knocking the K69, particularly since it is one of few reasonably priced drivers that I found to use in a two way setup. I don't know if the Faital Pro will be any better, but at least on paper its individual FR is better in the high end....or am I not understanding this correctly?

Like DrWho said hard to compare since the horns (and other unknown variables) were different for each test and also these plots appear to have different smoothing/resolution as well.

mike tn

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I'm still very interested in the potential for this driver. Can't wait for the test results.

I can add one thing to the testing being done by others on the Faital Pro HF200 driver. Yesterday, I installed a pair in Cornscala cabinets using the M2380 horn and CW1526 woofers. I did a 2nd order crossover at 400hz and did some listening for a few hours. I ran the power at about 100 watts for quite some time during this listening test. So, since the drivers lived through that torture test, seems to me that crossing them at 400hz for use in the Khorn is practical. Like a lot of others, I have searched for a 2 inch driver that could be used down to 400hz and still extend to the highest frequencies without a bunch of EQ AND not cost so much as to put it out of the reach of lots of folks. This just MAY be that driver.

Bob Crites

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Guest David H

1) is the idea to mae Klipsch 2way insead of 3way?

This is simply another option.

2 I dont' think I will ever undderstand the time alignig part explainaton . . . . . . . delay highs by how many millaseconds with prosessor may be??????...... but what do that have to do with 2way 3-way???????

Using a single driver for the top end is basically the same premise as as a time aligned top end. In a time aligned top both drivers are same distance from the listener or a delay has been used so the sounds from the individual drivers reach the listener simultaneously. Using a single driver with the same or better coverage as the combined drivers will have the same or better results.

Dave

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Guys,

We now have a new option.

Before we had:

3-way systems with response clear to 20 Khz but the tweeter was closer to you causing a time alignment issue but good high distribution due to a small tweeter horn.

3-way with a coaxial driver with response to about 16 - 18 KHz withOUT the time alignment issue. Both drivers are the same distance from you (B&C DCX50 driver). High frequency distribution is limited by the large horn needed to go down to 400 Hz.

There is also the 3-way system with extreme-slope crossovers option. This goes a long way toward limiting the time alignment problem but has the disadvantage of higher cost due to the complexity of the networks.

Now we have a new option:

A single driver that will go to 20 KHz withOUT the time alignment issue. The only problem remaining is that a single large horn that will go down to 400 Hz does not have a good distribution of highs. That is the problem with any 2-way full-range system I am familiar with.

Al K.

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I can add one thing to the testing being done by others on the Faital Pro HF200 driver. Yesterday, I installed a pair in Cornscala cabinets using the M2380 horn and CW1526 woofers. I did a 2nd order crossover at 400hz and did some listening for a few hours. I ran the power at about 100 watts for quite some time during this listening test. So, since the drivers lived through that torture test, seems to me that crossing them at 400hz for use in the Khorn is practical. Like a lot of others, I have searched for a 2 inch driver that could be used down to 400hz and still extend to the highest frequencies without a bunch of EQ AND not cost so much as to put it out of the reach of lots of folks. This just MAY be that driver.

Bob Crites

Bob, as I mentioned in my e-mail, I will likely get 3 of these driver for their ability to handle the very high octaves better than what I am using now. Ideally, I think I would prefer the 8 Ohm version. Please let me know when we can order.

It will certainly be interesting to see how it performs in my P. Audio horns.

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