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A time-aligned top end - Part II


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You are raising the question of "what is a Jubilee". In my book it is more than just a bass bin. .

One view is the "recipie" that was given in the JAES article by Delgado and Klipsch (JAES, 2000). They clearly outlined a 2-way system that used a 2in throat horn for the treble. The same engineer(s) further detailed their thinking in comments related on this forum etc. What emerges was 2-way design that incorporated a CD horn, attention to a crossover point that matched dispersion of the drivers, and perhaps time-alignment etc.

These design goals are not just for the Jubilee, they can be used elsewhere also. Again, I refer to the work of the guys at JBL (JAES article by Eargle et al regarding the 43xx monitor), or at Harman (Toole et al). My view is that it worth some time thinking about overall design goals before someone starts simply swapping parts. If you want to simply swap parts, I have previoulsy listed some CD horns that are readily available on eBay, why not give them a try.

Again, I am not picking on some of the fine craftsmenship that is being shown. But this is a "Updates and mods" section (and not the Garqage Sale section), so I think it is fair to examine these design issues.

If there were a plug and play Klipsch Jubilee consumer version these tweaks wouldn't be as necessary but there is a desire by many to hear PWK's swan song and it deserves to be heard.The Jubilee LF is a tweekers dream if done correctly. I'm very close to having the Jubilee pictured with PWK. The k403/B&CDE82TN 1.4in is a cool combo. The only piece I lack is the passive crossover they designed but I'll likely never see it. At JC's house last year we heard many combinations of two way and three way systems. I could have been happy with most of the combos. If your a tweaker and can't leave well enough alone there are some great options like the Ashley products and other but for me I want to plug and play and listen to music.

They might as well start a DIY section and toss us all in there LOL..

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Guys,

I think we are into one of those many unwinnable and age old argument entirely dependent on ones point of view! We all just have to agree to disagree. The objective here is just to develop another possibility. To each, his own, and all that sort of stuff! Besides, all this was really aimed at the Khorn, not the Jub.

Al K.

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If there were a plug and play Klipsch Jubilee consumer version these tweaks wouldn't be as necessary

Hey seti

Big SmileAre you sure about that..! Us Tweakers by our very nature are always having to mess with something..!

mike tn

True. I did say "as necessary". Some buy brand new sports cars only to take them to the next level or what they think is the next level. So I guess the same can be said for speakers.

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Guys,

I think we are into one of those many unwinnable and age old argument entirely dependent on ones point of view! We all just have to agree to disagree. The objective here is just to develop another possibility. To each, his own, and all that sort of stuff! Besides, all this was really aimed at the Khorn, not the Jub.

Al K.

Agreed..!

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Dang it! I wish you guys would stop this. I just finished cleaning the shop after my last build and now you are toying around with a new horn design. Great.....just when I thought it was safe for my wallet to look at the forum again....

On a serious note, very nice job gentlemen. I will be following your progress with interest.

GotHover, you mention the P-Audio BM-D750 requires a lot of EQ. It does require some, but unless my system is not set up correctly, it doesn't require an extensive amount IMHO. I had to add a hi shelf to prevent the very high end from rolling off too early, but other than that I don't recall doing much else. I will have to look at my Ashly crossover settings again since that was a while ago after I set up the DBBs.

BTW, after all the research I did, the first version of the BM-D750 is the K-69 with a different logo and paint scheme. The new version of that driver looks totally different.

Keep up the good work.

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Guest David H

Dang it! I wish you guys would stop this. I just finished cleaning the shop after my last build and now you are toying around with a new horn design. Great.....just when I thought it was safe for my wallet to look at the forum again....

On a serious note, very nice job gentlemen. I will be following your progress with interest.

GotHover, you mention the P-Audio BM-D750 requires a lot of EQ. It does require some, but unless my system is not set up correctly, it doesn't require an extensive amount IMHO. I had to add a hi shelf to prevent the very high end from rolling off too early, but other than that I don't recall doing much else. I will have to look at my Ashly crossover settings again since that was a while ago after I set up the DBBs.

BTW, after all the research I did, the first version of the BM-D750 is the K-69 with a different logo and paint scheme. The new version of that driver looks totally different.

Keep up the good work.

Thanks for the additional info on the BM-D750.

Dave

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Dave: If/when you guys get around to testing various drivers, please try to include the K69. I, for one, am very interested in what kind of performance you get with your horn vs. the more conventional horns we are all using. My P. Audio horns (I believe they are CD horns) have an interesting throat. It is actually square!?? I am very curious as to what differences there may be with your horn. I noted earlier in the thread the better hf response vs. the K2 horn. I would love to know if that is a driver issue in the tests or if that was due to your horn's round throat. Reason being that I am using the horn from 700Hz on up, in a basic 2 way setup.

Again, great work you and Al are doing on this.

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Guest David H

Dave: If/when you guys get around to testing various drivers, please try to include the K69.

Yes, I thing the K-69 would be a good test.

I noted earlier in the thread the better hf response vs. the K2 horn. I would love to know if that is a driver issue in the tests or if that was due to your horn's round throat.

Identical drivers and conditions were met during the test, the only difference was the horn itself.

Although the Eliptrac outperformed the square tractrix in initial testing, the polar plots recently performed show this horn is better suted for 3-way operation.

I am still planing on testing a few drivers, I am starting with the Selenium D-408Ti. I really dont need this driver to run full range, I would be satisfied if it would perform well as a midrange only. Previously I tested the D-405 phenolic, and although it tested good, it started rolling off around 4500 and fell of fast around 5k. I would like to find a good sounding, reasonably priced driver that will perform well from 400-6K+.

Dave Harris

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Guest David H

What is the status on the Eliptrac's?

How was the Selenium 408?

Craig 73

You would know, if you showed up this weekend... BTW, how is the Mother in law....LOL [:P]

So far I have built 5 pairs of Eliptracs, and I think they are ready.

post-24405-13819635853746_thumb.jpg

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Guest David H

How was the Selenium 408?

I am surprisingly pleased with the Selenium D-408Ti, it seems to perform graph good from 400-6000hz as a midrange. I have not done any serious listeneing tests as of yet.

The test on the D-408Ti included the removal of the Ferrofluid coolant from the voice coils air gap. This is only a preliminary test using my Ipod touch FFT analyser and a DIY mic. It looks to me like this driver deserves some additional attention, so as time permits I will re-run the test with Real RTA and a calibrated mic.

Description of Ferrofluid cooling. Ferrofluids are commonly used in loudspeakers to remove heat from the voice coil, and to passively damp the movement of the cone. They reside in what would normally be the air gap around the voice coil, held in place by the speaker's magnet. Since ferrofluids are paramagnetic, they obey Curie's law, thus become less magnetic at higher temperatures. A strong magnet placed near the voice coil (which produces heat) will attract cold ferrofluid more than hot ferrofluid thus forcing the heated ferrofluid away from the electric voice coil and toward a heat sink. This is an efficient cooling method which requires no additional energy input.

post-24405-13819635862344_thumb.jpg

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I keep coming back to this forum for one reason: all the good ideas being bandied about. It seems like this year may be the time to jump on some new technology or do the ultimate build I want. However, you guys keep inventing and tweaking and my ultimate keeps changing.

Keep it up.

Dan

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What is the status on the Eliptrac's?

How was the Selenium 408?

Craig 73

You would know, if you showed up this weekend... BTW, how is the Mother in law....LOL Stick out tongue

So far I have built 5 pairs of Eliptracs, and I think they are ready.

I think they might not be ready, better send a pair with a Fc around 500 - 600 that can be crossed a with 700Hz network from ALK.

Then we will do a Double Blind Study with another Mechanical Engineer using JBL & Selium Drivers and publish the results.

Of course I will need to keep the review samples.

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Guest David H

Of course I will need to keep the review samples.

I see you have done this before.

I used to love writing reviews, after about 5 year it became one big blur.

Dave Harris

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Guys,

I did a series of test on the P-Audio K69 equivalent driver a while ago with a loaner driver. I can't remember who loaned it to me though. I don't have the results here any more either. Drat! I think I posted them here, but I can't remember that either! 64 years old an a bad case of C.R.S.!

Anyhow, we need to find another driver that will handle a 400 Hz crossover. It turns out the B&C DCM50 I like is back-ordered until April with the distributor!

Al K.

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