Schmacks horn?

[Elbert]

Hi guys!

After I got rid of my Voight horn loaded Coral flat 8's, I've been listening to some "conventional" BR speakers.. and they are seriously boring.

The coral's were admittedly far from linear, but just somehow much more dynamic and engaging!

Missing that, I'm getting drawn back to the mythical attraction of horn loading and high efficiency...

Looking at a pair of 6" drivers I bought for midrange use in a future project, I realize that the moving mass is very low (6,75 g)and so is the Fs (38 Hz). efficiency is high at 92 dB w/m.

Then i stumble across something called the schmacks horn... hmmm.

Some claim they will only deliver a weak bass down to the (upper) 40 Hz region, while some places it is even referred to as a 35 Hz horn.

They are big boxes, but for a true (not to badly compromised horn) they are not that big.

does anyone have any experience with this construction? Can the 280 l + volume for each speaker be justified in any way compared to a closed or BR system at least half the size?

The prospect of reproducing low frequency information with a lightweight 6" driver acoustically impedance matched to the air (transient response?) is tempting, if it actually works...

Anyway, subjective opinions and practical experience will be welcomed!

[Elbert]

Here is some of what little I have found...

http://www.speaker-online.de/bauen/naumann/

[angeloitacare]

i have selected some links to informative sites about the Schmackshorn :

http://www.audiovoice-acoustics.com/...light=schmacks

and here a nice description how it sounds . in german, but you can translate it

http://www.audiovoice-acoustics.com/...read.php?t=430

[MaVo]

I built one of those when i was a teenager. Good old times

Apart from the obvious nostalgia, or rather somehow connected to it, i would say, because this is such an old design, you better look for a newer one, which will be geared towards a certain available driver and probably sound alot better. Besides, with hornresp you make up better designs (or rather, better fitting to your needs) in a matter of minutes.

Even if you decide to build them, simulate them with your drivers in hornresp first and have a look at frequency response and maxSLP. Chances are that horn and driver wont fit together. That might safe you from alot of frustration.

[Elbert]

Thanks for the links, allready looked through those though...

Hmm.. that horn calculation software was really interesting stuff....

Guess you are right, probably better to calculate som horns and simulate them with hornresp to ensure an optimal driver-match.

Guess I'll be struggling to reverse-engineer the horn data from the schmacks drawings in order to simulate anyway..

[Elbert]

Well, after playing around a bit with hornresp, Ive come to the inevitable conclusion that in order to obtain good low frequency response, some big horns are needed.

I sort of knew this allready, but seeing the function of varying length and moth-area in the simulations sort of drives it home i guess!

So, Scmacks, or any other LF horns are OUT for stereo use.

[franku]

I build a set some 30 years ago still have them, wouldn't trade for anything, just got to use the right speakers , started with ev's
sp8c and than switched to dynaudio, using bumpers now and they rip.

[wavewatcher]

Hi,
I totally agree with you , franku. I have had my Schmacks horns for 20 years now and consider them indispensable. I cant see a two litre sub as being comparable to a pair of these and I have listened to a few.
I have done A to B comparisons with many other enclosures, (IB, ported, smaller horns, both modern and vintage, hi-end-pro and budget). Bass response should not be an issue with these 'miniature' folded horns.
I would whole-heartedly recommend you make a pair , Elbert.
Apologies for lagging some years behind the original posting.

[weltersys]

Originally Posted by Elbert

Well, after playing around a bit with hornresp, Ive come to the inevitable conclusion that in order to obtain good low frequency response, some big horns are needed.

I sort of knew this allready, but seeing the function of varying length and moth-area in the simulations sort of drives it home i guess!

So, Scmacks, or any other LF horns are OUT for stereo use.

Tapped horns can be made fairly small and still have excellent low frequency response. You will see around 6 dB gain over the same driver in a slightly smaller bass reflex cabinet.
TH don't rely on mouth area to work well.
They sound kind of in between a bass reflex and a regular horn.
Hard to get them to work well over more than two octaves, so generally 80-120 Hz are the upper range of use.
Tons of designs in the sub forum, but since you have Hornresp, you can see how the drivers you have will perform in a TH of a given size.