Khorn & Fostex

[Dieter]

Hi guys,

i have a K-Horn with K33E, k55V, K400, K77M & ALK xover. I think this is a very good speaker. The ALK is a very, very good improvement for the Horn. But i thing the real very good thing is the bass-section. The mids & highs are not so very good. Many of us try to tweak these sections with dynamat the horns, change xovers and so on. My opinion is, that PWK makes a good job in the bass (it's the best bass i've ever heard), but the mids & highs are a compromise (the speakers are relative cheap, but PWK made the best out of them). I think, the best way to make a real good speaker, is to change the mids & high ( the total tweak).

Last week i have heared a Horn with the original bass-section, a Fostex D450 mid-driver, a Fostex H325 wooden horn and a Fostex T825 slot-tweeter. It was impressive:

Absolut no harshness in the mids&highs, a very smooth reproduction (Sorry, but i don't know all the english words for this sound.)

And last but not least the Fostex look very fine.

My question: Does anybody know these combination?

What do you think of these tweaks?

With regards

Dieter

[sunnysal]

the wierd thing is this; the k-horns weak section for me is the bass...while dynamic and punchy, it does not go down past 50hz...the mids and highs are quite good however, especially considering the relatively cheap drivers used...I am sure that if we take TAD or high-end JBL mid and tweeter horns, combine them with some other bass section (maybe that Pi speaker bass folded horn cabinet) we can get a better speaker...BUT if we are not talking about building own own then the K-horn makes a terrific compromise accross the board...well maybe a few tweaks here and there...

[jweed]

I replaced the midrange and tweeter on my khorns, with Altec 288 drivers and 805 tar filled horns for the midrange, and JBL 2404Hs for the tweeters. With the ALK crossover I'm in heaven.

[jdm56]

I'm with you on this one, sunnysal. My experience with klipschorns is like yours; I love the mids and highs, but bass is...problematic. I think the reason for the difference of opinions is mostly due to the differences in room acoustics. And also, the differences in hearing from person to person. I hear so many comments on the "rough" k-horn midrange, but I just don't hear a problem. In fact, the mids are for me, their stongest area. In my room, bass is rough below 100hz. Subjectively, it can sound absolutely great on one CD, then thin on the next. No doubt part of this is just the speaker "telling it like it is", but the overall impression is that the bass is just a little light. I sometimes just crank the bass a few dB, but this doesn't always cut it.

------------------

JDMcCall

[sunnysal]

Watch out James! you just admitted to tone control usage!...I too bump up the bass (or...keep this between you and me...the loudness) on the k-horns...my midrange, yes brutally revealing but that´s why I moved to tubes...all in all still the perfect tony zorn speaker...dynamic, loud as ya want it, and lets face it...BIG!...someday I may have a second system with B&W 801s, my McIntosh SS amp and a SACD player for that "fine" listening experience...but for now...blissful in Salvador...Warm regards, tony

[Dieter]

Hello sunnysal & James!

I think, that the point. In my room (4m x 7m)

I have no problem with the bass, it is powerful,very dry, so I like it. But the mids & highs. Next week I get the Fostex speakers and horns.

Regard

Dieter

[jdm56]

An outed tone control user - that's me! Actually, I'd prefer to bypass'em, but the fact of the matter is they sometimes can help.

And while I'm admitting things; I have been so frustrated with this room/bass problem that I am even at the point of considering selling my 'horns. I can't believe I'm actually thinking/saying that, but it's true. I have experimented, and come to the conclusion that adding a belle klipsch center speaker would greatly smooth and boost the bass below 100hz, so that was the plan until - poof! - no Heritage speakers are being made for the time being. And when production resumes, there will no doubt be a substantial price increase. It was gonna be a stretch affording one at the old price, even with a generous dealer discount. And I still would want a pair of heresys for surround, and possibly a sub or two. And then there's SACD / DVD-A...

...So, where does this leave a working class audiofool with a mortgage, one stay-at-home wife, two kids and #3 on the way? I'll tell you where: doing some serious math. I figure when the new heritage prices come out, my horns are going up in value, too. So maybe I'd be better off with a more affordable, tunable system. Something like the new Reference sats, with a sub that I could place where it would rock my music room.

Oh, I dunno. I must be nuts. I'm even thinking about some other "high value" speaker brands, like Paradigm and Definitive Technology. Somebody slap me.

Maybe I could get on "Millionaire"...

-

------------------

JDMcCall

[John Warren]

what do Fostex units costs in Germany?

[sunnysal]

Dieter, let us know how it turns out...I am curious why not TAD or JBL drivers?...James, why not a pair of used belles before dumping the heritage speakers? I have some RB-5s "reference series" klipshes and I have to tell you if you like the heritage series I do not think the reference series will do ya´ MTC but...Ebay has belles now and then for reasonable prices...regards, tony

[J M O N]

James,

Snap out of it!!

Go get yourself some used Belles if you have to. A used pair will probably be cheaper than a new single one anyway. You can always go in with someone else that needs one too, there always seems to be someone here that is looking for just one. A single Belle is hard to find. I was lucky and found one available, but I had to drive a long way to get it.

[jdm56]

Sunnysal & Jmon,

Thanks for talking me down from the ledge. Last night, after more measuring and listening, I seem to have found a spot where my 80 and 50 hz nulls are down from the 1khz spl "only" 8 and 12dB respectively. Other than that, the bass was really good. I put on the O'Kanes first CD and - wow, it sounded gooood! Bass was clean, tight and solid.

But man, I can't believe how room dependent a big pair of 'horns can be. In my room, (maybe most rooms) six inches one way or another can have profound effect. And as you know, cornerhorns don't allow you much maneuvering.

Financial considerations (and spousal pressure) still has me considering a change, but not before the heritage line is in production again. We'll see what the prices do, and what kind of luck I have in finding a belle. (oak oil, '82 or newer, and must be in excellent shape - no party dog) I wonder if there could be any audio life AFTER klipschorns, anyway?

------------------

JDMcCall

[sunnysal]

james just to add fat to the fire, I might be able to "go halfsies" on a pair of belles with you...I havebeen looking for one birch ply belle to put between my k-horns...maybe we'll come across a pair sometime and split them up...meanwhile, glad to hear you're still in...get tone controls or, god forbid, an equalizer to bump the 50hz and and 80hz nulls and hold on...regards, tony

[jdm56]

Yes, splitting a pair of belles is a possibility - but I gotta have oak oil!

I'm not really against tone controls, but I do try to avoid them with careful speaker/room dial-in. It's just that with cornerhorns, there's only so much you can do. As for EQ, I think they can be great for some things, but not for fixing nulls. I really think only "heavy lifting" can do that. By that I mean structural changes and/or speaker changes (more, different location, subs...)

At any rate, thanks for the advice.

------------------

JDMcCall

[sunnysal]

oak?, oh well...when I meant EQ I meant parametric or possible something like the z-systems unit...where you can focus on those specific frequencies...that wouldn't help? regards, tony

[jdm56]

Hey Tony,

I've got an old Sony TA-E1000ES A/V pro/pro that has a built in 3 band digital parametric eq with selectable center frequency to 1/3 octave, selectable "Q", and up to 12dB boost/cut per band. And the three bands can all be lumped together to provide up to 36dB boost/cut on one selected band. I tried that method to fix an 18db null at 50hz. Even with the highest Q filter, I could only bring up that band about 9dB. So you can imagine the amount of amp. power and driver excursion required even to do that. In short, it's kind of like trying to fill up a black hole - it can't be done. This dilemna really only applies to cancellations and nulls, I believe. More minor frequency response dips caused by, say, room surface absorption or simple speaker output variations, can successfully be remedied with a good EQ, IMHO, of course.

------------------

JDMcCall

[Klewless]

Tone Controls?

Here's my take on the subject.

I believe that if I were forced to use tone controls that it would be better to use an EQ instead. Just consider it a more sophisticated tone control and fight the temptation to move all those sliders all over creation. Generally the problem with tone controls is that they are not selective enough. They just cover too broad a range to be truely useful. Some older preamps had EQ in the bottom of the spectrum to help with the room resonance problems.

------------------

John P

St Paul, MN

[WMcD]

If I may comment on James' issue.

Mostly theory here. (Am I being a prig?)

Suppose you have a reference level of 90 dB. If a relection is equal and out of phase by 180 degrees, then you can have a null down to nothing at that location. (Call it 0 dB.) Obviously a perfect reflection is impossible except in a tube. However, roughly speaking, it could cause a null (cancellation) down to absolute silence. Certainly a 20 dB "loss" at a node in a room is more than possible.

On the other hand, a perfect reflection could lead to a +3 dB or so peak at a location where it in phase. About double power. But that is all. You can't get a 20 dB peak from an in phase reflection.

The conclusion is that the peaks are limited to about +3 dB. But nulls really are deep holes. It's not too far off to say that you wind up with 93 dB at a peak and 70 dB at a null).

I used a tone generator putting out about 50 Hz and walked around as an experiment. At one spot, you'd think the speaker wasn't working at all. At other spots a few steps away, the sound is more than healthy.

The problem with equalization is that you can crank up the source, but the out of phase reflection goes up by the same relative amount and cancels by the same strength! So the hole is still there.

In short, James' observations are certainly well based in physics. The math works out that the mountains are not so high, but the valley are really low, and there is little you can do about them with equalization.

Of course the real "problem" is that if you shift the frequency up or down by a few notes, the peaks and nulls move to other locations in the room.

Gil

[jdm56]

Gil,

Thanks so much for the observations. Of course, with "normal" speakers, there are many more ways to deal with things like this. But with cornerhorns, you're really limited. You can only move the listening position so much fwd or bwd without degrading imaging and focus.

I designed this listening room with k-horns and a center belle particularly in mind, while allowing for the possibility of something else, too. Specifically, I built in an offset in the middle of the front wall, for the belle to set back into. This offset is 18" deep and 3' wide at the back, flaring out to 6' wide at the main wall (45 degree). Behind this front wall is the unfinished basement wall. The stud wall itself is of 2x4 construction on 16" centers, with R-11 fiberglass insulation behind textured half-inch sheetrock. So that wall is relatively springy and lightly insulated, with an extremely reflective, hard surface 18" behind it. Could this be the source of the cancellation? Or do you think it is probably an interaction between two of the interior surfaces? The overall room dimensions, excluding the alcove, are 18.5' X 16.0' X 8.67'.

When I was planning the room dimensions, my main concern was avoiding pile-ups of room modes. And in this I was successful. Plus, the two modes between 30 and 40hz help to shore up the horns falling output at those frequencies. But my knowledge was insufficient to predict cancellations, and is still insufficient to ferret out the cause of them.

I have found a good spot, where the notches are down just 12dB at 50hz, and 8dB at 80hz. And subjectively, on most recordings with good quality and quantity bass, the sound is very good. But still, just the knowledge of those notches bothers me. (I know; I'm sick.)

Well, please excuse my whining, and for repeating myself, but if you've got any idea how to find the offending dimensions, or what to do about them, I would GREATLY appreciate it.

Thanks,

------------------

JDMcCall

[Randy Bey]

JD,

I know the proud papa syndrome, and I hope I don't offend, but have you considered building DIY sound absorbtion panels and bass traps?

The nice thing about these items is that they are tunable -- you can add or subtract, move them about, etc. until you find the "right" combination.

I surely do know what you mean about those dips staying in your mind. Like a hole in your tooth that the tongue keeps moving towards, these things are very hard to put out of mind.

But, since I don't know anyone with a perfect room, or perfectly flat speakers in that perfect room, perhaps it is best to imbibe mass quantities of malt beverages until the unpleasant memory of peaks and troughs go away....

[Dieter]

Hey!

I've got the Fostex H325 with D450 and the T825 Slot-Tweeter. The ALK crossover lets match the D450 to the bass, it's a very good thing. I'm very satisfied. It is very difficult for me to describe the sound in English. I like the sound and i'm very happy.

The costs for the units are about 380 $ (used in good condition).

Why not TAD? Too expensive (not available used in Germany)!

Why not JBL? More expensive then Fostex and hard to get used too in Germany. And I think they are equal to the JBL's.

Dieter