Khorn low frequency capability

[Rudy81]

What kind of actual response are you guys seeing with the Khorns in bass? I was messing around with my sound meter and test discs and noticed that when the tests hit around 50Hz, the bass rolled off rather dramatically. I realize room acoustics can greatly affect the results, but am wondering if I'm missing something.

[bhendrix]

Rudy,

My K's are on the long wall in a room 24 x 17.5 x 8 and are strong, tight, fast and clean down to 30. Any subwoofer I've tried, so far, has not been as clean and fast as the K's. For HT in this room I use "K, LaScala, K" up front and Cornwalls rear and the sound is awesome with no sub. For 2 channel, it's K's alone. Anything else detracts.

I suspect your roll-of at 50 is room related.

[Rudy81]

I am guessing that could be the problem. The bass is amazing down to the 50Hz level. Mine are in a 20x27x9 room, along the short wall due to HT seating setup.

I am also using some false corners I made. The corners are tight and very heavy due to the method I used for construction. I will have to make some more detailed testing before I start messing with things. I also need to accurately (?) measure the frequency response in the 30Hz range to see if the problem is due to room problems.

[bhendrix]

Just move one of the K's to the long wall for a test and I'll bet you'll be amazed at the difference. I tried mine on the short wall for HT and lost much of the deep bottom end. I was surprised by the difference. They went immediately back to the long wall!!

[sunnysal]

I seem to remember that a well placed k-horn should be 10db down by

30hz, not say say there cannot be response down to30, just that it

rolls off VERY fast below 35hz (I think 35hx is the 5db down

point). In my room they drop off rapidly below 50hz, I

think they do a great job to 50hz, though sometimes I wish for another

20hz extension. Warm regards, Tony

[djk]

PWK published the response of the current Klipschorn in the October 2000 JAES (fig.9).

The response is 98dB at 60hz, 97dB at 50hz, 96dB at 40hz, 95dB at 35hz, 90dB at 30hz, 86dB at 25hz, 81dB at 20hz.

About 100dB at 100hz, a peak of 107dB at 160hz, 100dB at 200hz, and another peak of 108dB at 250hz, and 100dB at 300hz.

[sunnysal]

Thanks Dennis, you always come up with the real goods. using

100db as the reference level (matter of opinion I guess) 10db down at

30hz. Warm regards, Tony

[chops]

Precisely the reason why I use subwoofers with any loadspeaker I use. []

[dubai2000]

chops,

I couldn't have said it any better...[]....at least in my room the sub makes a big, positive difference....wouldn't want to be without it. Trusting my ears and a test tone CD I seem to recall that bass rolls off quite clearly at around 45-50Hz.

Wolfram

[chops]

Yes, but what exactly is a "loadspeaker"? LOL

Ooopsie! A little typo. [:$]

[jdm56]

I had k-horns in two different rooms (when I had k-horns!). My problem was never bass extension, so much as it was bass smoothness. The first room I had'em in was 16x13x10 with one short end being basically open to the rest of the house. The sound in this room, subjectively speaking, was very good. There was a strong resonant peak around 50Hz combined with a sharp notch at 40Hz --very hard to teat with anything but a good multi-band parametric EQ, which I happened to have at the time! Still, in spite of the rough meaurements, the sound was killer in that room.

The second room I had them in (different house) is 18.5x16x8.67. The sound of the k-horns in this room is hard to pin down. At times I thought it was great, at others I thought it was horrible. The thing with this room is that the front corners were just bad places to try to do bass unless I crammed the futon all the way back against the back wall. There, it was decent but rough. If I sat out away from that back wall the bass just disappeared. It was OK at 100Hz, but way down at 80 and WAY down at 50; just extremely rough.

To make a long, sad story less long but equally sad, in both rooms I used k-horns, the bass was falling off like a rock below 40Hz, while the range from there up to over 100Hz was totally room dependent (in my particular case --rough...which explains why I now use small speakers and multiple subs!

[D-MAN]

Along with what DJK said above, the current Khorn is published as having a -3db down point of 33Hz. Sort of depends on where you measure from, don't it?!

{edit} I ws looking at my 1978 Khorn flyer and it stated 35Hz - 17Khz +/-5db!

Quite a difference for the same drivers, etc., ain't it?

DM

[PrestonTom]

Along with what DJK said above, the current Khorn is published as having a -3db down point of 33Hz. Sort of depends on where you measure from, don't it?!

DM

We must remember the wavelengths involved....

A corner loaded horn is not (and should not be measured) in an anechoic environment. Most of this discussion is confounded since you are really talking about the cabinet/room as a system. This is about room acoustics at these low frequencies.

Good Luck,

-Tom

[D-MAN]

Yes, but I meant from WHERE in the response curve the -3db point was "selected" from a reference frequency!

DM

[Peter Parts]

As far as I know, not possible to take measurements and predict accurately your experience of quality bass in your living room, not that it wouldn't be helpful to have such a measurement. Easier to find specs which anticipate HF experience reasonably well.

Without electronic augmentation, Khorns do not go awfully low (but surely low enough) and they are not awfully smooth (but smoothness is not a direct listener experience parameter).

But there is nothing you can readily buy off the shelf that cleanly and potently wafts about great masses of the air in your room in response to good bass in a CD.

[WMcD]

All this is true.

The AES paper showed response in an outside corner. I had posted an old review from France which seems to show about the same. In an outside corner, response is very far down, maybe 20 dB or more, at 35 Hz..

OTOH, PWK published room response which looks pretty flat down to 35 Hz. Then it goes to heck You just knick the edge of honesty at 32 Hz..

This means that PWK was doing the curve in the most favorable room he could create. And probably you had to have two K-Horns in good corners to do it. This requiires about 20 dB or more of room boost. That is tough target in room design.

Gil

[Rudy81]

The room, any room, will affect the sound of any speaker. I will have to take some time and do some full frequency testing on the effects of my room. Thus far, I had made some corrections, via absorbers, by ear. I did note the problem in bass in the very low area and confirmed it with my testing. I really hate trying to work on bass problems, those are much tougher to clear up than high and mid freaquency problems.

[Rudy81]

Ran the test disk and took some numbers down in my sweet spot with the ever reliable Rat Shack meter (obviously not a true scientific evaluation). Pink noise set at 80dB at the listening position:

20kHz 50dB
16kHz 63dB
12.5kHz 71dB
10kHz 79dB
8 kHz 85dB
6.3kHz 90dB
5 kHz 90dB
4 kHz 86dB
3.15 kHz 81dB
2.5 kHz 81dB
2 kHz 82dB
1.6 kHz 80dB
1.25kHz 80dB
1 kHz 79dB
800Hz 78dB
630Hz 74dB
500Hz 78dB
400Hz 77dB
315Hz 79dB
250Hz 82dB
200Hz 84dB
160Hz 90dB
125Hz 86dB
100Hz 87dB
80Hz 78dB
63Hz 75dB
50Hz 78dB
40Hz 77dB
31.5Hz 70dB
25Hz 77dB
20Hz 73dB

Wow! Considering the limitations of the Khorn, it seems the bass is just fine with the exception with a room problem at the 31Hz range. However, as the tweeters go, they definately need help. I may have to try Bob's new units. From 4 to 6 kHz there is certainly a problem. I do have my ALK crossovers set to attenuate the mid horn by 6db's.

[DRBILL]

Let's get the flame-throwers lit. I listen to a lot of well-recorded pipe organ music. I have demonstrated to all who have visited my home that the K-Horn has output at low C (CCCC) of an open Principal 32'. The last octave of this rank is c.16-32Hz. So how do we know the K-H has output at this low frequency? You lean your head back and rest it on the sheetrock! It is unmistakable. This is a valid test because you cannot hear 16Hz-- you FEEL it in your chest and abdomen.

A good recording to experience this is The Great Organ at Methuen (TELARC: CD-80049) Listen to selection 3, "Passacaglia and Fugue in c minor".

I have never felt the need for a sub with K-H.

DRBILL

[bhendrix]

AMEN, DR. BILL