Horn Speaker Are Hard To Make Them Sing

It's harder to make a pair of big horn speaker(15" bass unit) sing compare to others.
I have heard a few systems that playing with Klipsch K-Horn and Altec, they are either no bass or too much bass. Lacking of speed and control at most time.
What is the cause for that? Anyone can share your view?

Cheers,

Is it? I don't have such problem when I was using Klipsch Ref IV with 98db even when driven with 12W tube amp. Can't even turn the volume knob past 10 o'clock.

Hi Arremie,
I'm referring to those horn loaded big 15" n not those vented or sealed box speaker with horn tweeter speaker. Sorry that I didn't make clear at the begaining.

Cheers,

Hi noodle88 I am somewhat of a horn enthusiast and I know of the problems you are speaking of. Horns like the Klipsch K-horn and Altec horns are vintage horns - meaning they were designed to be used with low powered amplifiers, typically about 3-10W. Back when these speakers were sold, amps of 20W were considered high power.

As you know, a low powered amp with high output impedance is never going to have enough damping factor to control a large, tightly sprung woofer in a sealed box - these woofers typically sound more tight and more linear, but also require big, powerful amplifiers - preferably solid state. So the designers of these speakers made the woofers as friendly to low powered amps as possible - they are loosely sprung, and they are built into enclosures where the back wave is used to augment bass energy, rather than modern enclosures which treat the back wave as something to be gotten rid of.

The result is as what you hear - the loose spiders, the low damping factor of the amp, and the low Q of the speaker enclosures do not adequately brake the woofer cones once they have been set in motion so they tend to sound flabby. The back wave, once it emerges from the ports, is out of phase and time delayed compared to the front wave. The enclosures are not rigid and tend to store and re-radiate energy, which colours the sound even more.

Even vintage horns possess a speed which is hard to match even with modern drivers. The next time you get to hear these horns, listen carefully and see if you can guess where the crossover point is. It should not be too hard, because you should be able to hear it quite clearly. It is the transition point where the sound is flabby and the sound is fast.

There are also differences between the vintage horns of Klipsch and
Altec with modern horn profiles such as spherical horns or Le'Cleche
type horns. There are many people who love the sound of vintage horns
but I must confess I have never been a fan. I hate that vintage sound.

IMHO they can never be made to sing. That was the way they were designed, and technology has moved on.

noodle88 wrote:Hi Arremie,
I'm referring to those horn loaded big 15" n not those vented or sealed box speaker with horn tweeter speaker. Sorry that I didn't make clear at the begaining.

Cheers,

Try to match it with vintage stuff like leak,quad,dynaco,darling or fisher its sound good with me...

Hi Wongkk,

My personal view is that, there is nothing wrong with these vintage horns u call it. They just sound fantastic. They are highly efficient 104db. Just that u need a very good front end to drive the speakers.

As rubbish in rubbish out, they are so sensitive, any bit of noise from your system, the speakers will show it. So u need a super low noise, very fast with good control system to make it sing. It's possible.

Cheers,
The Noodle Guy

fizi wrote:

noodle88 wrote:Hi Arremie,
I'm referring to those horn loaded big 15" n not those vented or sealed box speaker with horn tweeter speaker. Sorry that I didn't make clear at the begaining.

Cheers,

Try to match it with vintage stuff like leak,quad,dynaco,darling or fisher its sound good with me...

Hi fizi, I don't think those vintage amp are fast and quiet enough.

Cheers,
The Noodle Guy.

noodle88 wrote:Hi Arremie,
I'm referring to those horn loaded big 15" n not those vented or sealed box speaker with horn tweeter speaker. Sorry that I didn't make clear at the begaining.

Cheers,

oopps my bad

The earlier-year horn speakers were designed for pro-audio use (theater, concert halls or PA systems) and was later adopted for home-fi use by flea-powered tube amps enthusiast due to its high efficiency. A number of these pro-audio equipment is reputed to sounds great! GE, Altec, TAD, Gauss and Klipsch have manufactured some great compression drivers and woofers, and specific models that is used for home-fi fetches premium among the DIY fans.

I have a DIY Altec 828 VOT horn speaker/300B tube amp that is my primary music system now. It has the "in-concert" sound but with clarity, bass and sound-stage. The equipment I am using are over 30+ years old but still sounds great.

My experience with vintage speaker equipment :-
i. Recap the crossover's capacitors - it may dry-out due to age or values may have drifted affecting the crossover frequency. In my experience, after I changed the caps in my Altec crossover, the clarity and bass improved. However, finding the same components in NOS is difficult.
ii. Build a new crossover that is tuned for home use. Pro-audio speakers focuses on specific areas - e.g. low bass, good mid-range (PA system); bass + midrange but no HF (theater), etc. Home-fi is a more demanding and require a balance.
iii. Check the compression driver's diaphragm for damage. 2nd hand equipment used in pro-audio may have some abuse and may require maintenance/replacement.
iv. Recone/service the woofers for optimal bass.



My experience

noodle88 I agree that all horns do things that other speaker technologies can not. However, I was wondering whether you have had the chance to listen to a more modern horn - e.g. something from Avantgarde, Cessaro, Acapella, Lansche, Faerber, or Zingali? If so, what do you think of the sound of these compared to Altecs, JBL's, and Klipschorns?

I could probably go on forever about these horns and why they are different, but I realize that fundamentally your taste is different to mine - which is why we are both horn enthusiasts but went in different directions

Anyway, coming back to your original question about how to control the bass which lacks speed and control - I am hoping that I answered your question by pointing out that the total system Q on the bass cabinets which are typically installed with these horn speakers is usually very low. The solution is to increase the Q by:

- using a solid state amp with a high damping factor,
- plugging the ports on the bass cabinet. This will provide more air spring - leading to tighter bass. But this also lowers the efficiency and steepens the slope giving you less bass.
- stuffing the bass box with foam instead of air.

I agree with your comment that horns require extremely high quality amplification. In fact the horn and the bass cabinet require different types of amplification - which makes sense because they are different types of drivers.

Hi WongKK,

2 days before this I did drives my Tannoy Westminster TW with a pair of 3.5W 2a3 amp. The preamp is a pair of custom built 45 tube preamp with line transfomer output. The music produced is beyond anything that I ever heard so far. Due to my speaker has only 99db, the amp can't go super loud like 120db.
Cheers,

Hi noodle, you are a lucky man if you own a pair of Tannoy Westministers! I have heard them in a couple of systems and they are a stunning speaker indeed. The dynamics are realistic, as opposed to some horns which can sound a bit overblown. And they are coherent, unlike most horns. There is no need to go to 120dB anyway. My listening level is usually about 85dB and with dynamic peaks, up to 100dB. I have no need to go louder.

Cheers,

Keith

Hi Keith,
Coming week will drive my Tannoy with a pair of custom built 300b SET poweramp. I expect this pair will sound even better than the 2a3. As I'm going to move my system to a bigger space, I op for the 300b amp.

Cheers,