How Do Horn Speakers Get Their Gorgeous Life-like Tonality?

[Audiophile Bill]

I have to get my speaker done... $20k-ish and with a horn covering 400-15,000 Hz can be used in smaller spaces. The driver is competitive with AER, I have heard and owned AER. They are excellent though, one of the world's best single driver speakers for sure. Makes Voxativ sound a bit bland.

Hi Dave,

Yes spot on. The Voxativs are a bit average next to the AERs. Not sure whether you ever heard the Stamm driver in the Loth X Horns. That driver has some serious magic - fastest driver I ever heard.

What is your horn? Can you share any details on PM.

 

[christoph]

I have to get my speaker done... $20k-ish and with a horn covering 400-15,000 Hz can be used in smaller spaces. The driver is competitive with AER, I have heard and owned AER. They are excellent though, one of the world's best single driver speakers for sure. Makes Voxativ sound a bit bland.

Finally.
Congrats.
Can we see some pictures, please?
Maybe even a separate own thread?

 

[kodomo]

Time alignment is nothing more than marketing nonsense. Phase matters but it's a moving target. People don't even like overly tight bass because it sounds sterile. If you want it more defined then not having a port or transmission line is a start. Ports resonate so by design they're not as accurate since the resonance is between the port and driver.

Time alignment is not a marketing nonsense or maybe I am not understanding you clearly I guess you were trying to say something else. I am not talking about just physically aligning drivers. I am talking about measuring impulse response and correcting upon that.

If you think alignments has no audible effects, take your midbass a meter back relative to the rest of the channels and listen to it. I lived with klipschorns. I heard we's without delay. You can easily hear this problem. Just get a dsp xo for a fun test. Delay your channels out of alignment. If you go further enough, you can even hear apparent echoes from your system playing transients. Welcome to Hollywoods problems with horns when they introduced bass to movies!

Not having a port is definitely the way to go. I also know by experience I prefer sealed bass. I had to do ports with my woofer boxes. The drivers I have were designed to work that way (TAD 1601b's) but they are so under the limits, I do not hear any problems relating to ports with them. I have 2 tad 1601b's in each 200lt boxes with two tapering large ports, just playing from 40-50hz to 120hz. Still, this is the only part I plan on improving with my speakers.

 

[Folsom]

Time alignment is marketing nonsense. Impulse response is not time alignement. People want to believe placement can correct impulse deficiency, but it cannot. Impulse is the driver’s self limitations, unless severly inhibited (unusual). Portrd and LT can still have good impulse.

In the case of the TL there really isn’t enough compression so what is leaving the box is lagging anymore than sound that reflected off the baffle, floor, etc. The pressure actually gains speed in the smaller area and then slows back when it exits. A lot of this depends on chamber design. Either way the front of the driver is going to give you enough edge. Plus these frequencies are so long that we can’t distinguish seperate sources within several feet of eachother (barring any rattling).

If you seperate drivers vastly too far, then they sound like seperate sources. They could still be in the same “time alignment”. You see there are a lot of factors that change during “time alignment” adjustments & speaker designs. Just because there is correlation does not mean causation.

IMO ape enclosurers are the only thing I am distinctly into anymore. (Aperiodic) I can understand why people like other stuff, as some crave raw power, but I am resolution gluten.

 

[KeithR]

I am not talking about just physically aligning drivers. I am talking about measuring impulse response and correcting upon that.

An acoustics expert used impulse response in my room for speaker placement and ended up with one speaker 6" further into the room to account for my non-parallel rear wall.

The center image was excellent, but the rest of the soundstage was twisted ever so slightly. Instruments around the center image weren't in the exact right place. It really bugged me after a month, so I switched back.

So I don't think its as easy as just correcting for impulse response in all rooms.

 

[kodomo]

There is no one solution and sometimes there are more severe problems to address first. However, if you have sorted most of your problems out then why not solve the rest you can.

My room is symmetrical, big enough, acoustically treated and does not work against my system. My channels are apart but they sound cohesive, unless you are too close but this was apparent even before building the system. I can live with that, I designed my room knowing that. There are so many things that have been solved up until this point. In my case, the last step was the alignment of the channels based upon impulse response. This is one of the two things I readjust when I move. This and the attenuation levels of relative channels. In the end I have satisfactory sound audibly for my ears and measurably for my mind. Love it when those meet and work together

 

[Folsom]

Impulse response for a room makes sense. You aren’t trying to hit the start of the curve, but rather make sure the room dissipates energy quick so you aren’t resonating real bad and losing definition.

But as with Keith, it may have serious limitations. Compared to FR, I think it has real merit.

Kodomo, how exactly did the speakers move when adjusting for impulse?

 

[kodomo]

I sit further and a little higher than I used to sit. The room is also bigger and have more suiting treatments. So after these changes, I remeasured and the channels ended up moving closer in the horizontal.

I guess, I have actually did what you say is not worth doing. I adjusted according to rises of each channel. (keep in mind my crossover is also 1st order)

The sound is located in between my tweeter and the upper mid. I hear very good transient response. The decay follows the frequency response without deviation.

I think for furthe detailed questions about my system specifics, pm would be more appropriate. I do not want to take over this topic.

 

[Folsom]

You have horns, seems somewhat relevent that you have found the angle to be important to getting that correct sound. Is tonality a part of the improvement?

I am not opposed to orienting a speaker with tilt action. It is just the improvements are not “time alignment”. For example you’re changing the lobeing pattern by doing that.

 

[kodomo]

You have horns, seems somewhat relevent that you have found the angle to be important to getting that correct sound. Is tonality a part of the improvement?

I am not opposed to orienting a speaker with tilt action. It is just the improvements are not “time alignment”. For example you’re changing the lobeing pattern by doing that.

There is no tilting. Just moving them forwards and backwards in the horizontal plane.

 

[Folsom]

I have no opposition to that.

 

[christoph]

I think for furthe detailed questions about my system specifics, pm would be more appropriate. I do not want to take over this topic.

Thanks, Kodomo
I find your elaborations about your awe inspiring system very interesting and educating.
Maybe we could re-locate these questions into your System Thread...

 

[morricab]

An acoustics expert used impulse response in my room for speaker placement and ended up with one speaker 6" further into the room to account for my non-parallel rear wall.

The center image was excellent, but the rest of the soundstage was twisted ever so slightly. Instruments around the center image weren't in the exact right place. It really bugged me after a month, so I switched back.

So I don't think its as easy as just correcting for impulse response in all rooms.

So, he was looking more at the reflections in the room and such to see where he could minimize the interactions and get a cleaner impulse?

 

[morricab]

Time alignment is not a marketing nonsense or maybe I am not understanding you clearly I guess you were trying to say something else. I am not talking about just physically aligning drivers. I am talking about measuring impulse response and correcting upon that.

If you think alignments has no audible effects, take your midbass a meter back relative to the rest of the channels and listen to it. I lived with klipschorns. I heard we's without delay. You can easily hear this problem. Just get a dsp xo for a fun test. Delay your channels out of alignment. If you go further enough, you can even hear apparent echoes from your system playing transients. Welcome to Hollywoods problems with horns when they introduced bass to movies!

Not having a port is definitely the way to go. I also know by experience I prefer sealed bass. I had to do ports with my woofer boxes. The drivers I have were designed to work that way (TAD 1601b's) but they are so under the limits, I do not hear any problems relating to ports with them. I have 2 tad 1601b's in each 200lt boxes with two tapering large ports, just playing from 40-50hz to 120hz. Still, this is the only part I plan on improving with my speakers.

Agreed, and nearly all speakers that I have liked in the last decade or so were all time-aligned so that they make a reasonable step response curve (I would use this test rather than impulse response to judge time-alignment). Impulse response also works but is convoluted with resonances and reflections from the drivers, cabinets and possibly room.

I too did speaker development using a digital crossover with time-alignment capabilities so that I could play with time-alignment by adjusting the delay of the drivers. Very educational.

As to bass alignments, I prefer horn or sealed box in general but also the Tapered Quarter wave tube (of Voight pipe) design, which is kind of a horn/reflex hybrid can work very nicely. That said, I have heard vented systems work very well but not in the way they are typically designed. They have to be designed with a relatively low Q so that there is no boom or overhang. Of course then they also don't extend and give as much advantage in the power department over a sealed box and usually a Q of around 0.9 is implemented, which gives a sloppy sounding bass, IMO. Going with something more critically tuned will give a good sounding vented bass. When I designed a planar magnetic hybrid system I went with a sealed box with a Q of around 0.6-0.65 that was tuned to around 40hz. Bass in room was usable to around 30hz from a 10inch sealed box.

Now though I have horn bass from my big Odeons (not big compared to your speakers just big compared to my other speakers) that are flat to around 45hz with usable bass to about 35Hz...not super deep but super punch and drive, especially the midbass...kick drums and tympany whacks etc. are just superb.

 

[morricab]

Time alignment is marketing nonsense. Impulse response is not time alignement. People want to believe placement can correct impulse deficiency, but it cannot. Impulse is the driver’s self limitations, unless severly inhibited (unusual). Portrd and LT can still have good impulse.

In the case of the TL there really isn’t enough compression so what is leaving the box is lagging anymore than sound that reflected off the baffle, floor, etc. The pressure actually gains speed in the smaller area and then slows back when it exits. A lot of this depends on chamber design. Either way the front of the driver is going to give you enough edge. Plus these frequencies are so long that we can’t distinguish seperate sources within several feet of eachother (barring any rattling).

If you seperate drivers vastly too far, then they sound like seperate sources. They could still be in the same “time alignment”. You see there are a lot of factors that change during “time alignment” adjustments & speaker designs. Just because there is correlation does not mean causation.

IMO ape enclosurers are the only thing I am distinctly into anymore. (Aperiodic) I can understand why people like other stuff, as some crave raw power, but I am resolution gluten.

Just because marketers misuse the term "time-alignment" doesn't mean it is nonsense or that it is not the same as a perfect impulse response. The term time-alignment means that all drivers in a speaker are delivering their impulse to your ears or the microphone at the same time, without delay. Another way to look at htis (more accurate, IMO) is the step response. When a speaker is truly time-aligned then the step signal in will give a triangular response out. This is because the speaker cannot hold the "step" and the output drops off. If all signals from the step arrive at the same time then the leading edge of the triangle will be sharp and all going the same direction. It is funny to see a step response with the tweeter or midrange going negative on the step. Clearly there is not time alighnment this way with all drivers move forward together in unison. Impulse response is messy with other issues but can still tell if things are basically going the right way.

I believe I can hear this as I have preference for time-aligned speakers and full-range drivers (particularly electrostatic drivers). Also, my experiments with DSP and demos I have heard once a speaker was time-aligned are pretty convincing that this can be heard.

 

[morricab]

Isn't this whole hobby driven by insensible decisions?
I could visualize them in our living room, but then again the Universums are really extremely good
How much is the retail price of the Pnoes anyways?

Hey Chris,

2 comments:

> Most of the previous horn dems I had heard honked too much for my taste. It put me off the breed. I realised their potential in the WE demonstrations though.

> I was actually pleased with myself for taking the step to get out and resolve it. Many folks get deeper into the abyss and try to argue their philosophy - thankfully I am not so inclined

Oh yes, deep indeed! I heard a WE demo...actually it was Line Magnetic WE clones but it was awesome and I heard it twice. The AcousticPlan manufacturer was demoing them and was importing them into Germany...was a great 40K system with one of the midsized snail horns (15A maybe) the little horn tweeter (can't remember now) that doesn't really go that high and then a big Jensen field coil bass driver with a short horn front side and some kind of box (sealed?) behind. The mid driver was a 555 copy I think and the tweeter driver was also a copy of a famous WE driver. The power supply for all these field coils was a huge tube powered thing. Awesome.

 

[DaveC]

Hi Dave,

Yes spot on. The Voxativs are a bit average next to the AERs. Not sure whether you ever heard the Stamm driver in the Loth X Horns. That driver has some serious magic - fastest driver I ever heard.

What is your horn? Can you share any details on PM.

I have not heard the Stamm, but I'll check it out given an opportunity. Feastrex can be pretty amazing too, Lotus Audio's Grenada OB is really nice.

The only thing about my speaker that's changed is selling it direct, I have a simpler cabinet design that doesn't need to use vacuum forming for curved walls so I can both keep costs down and find a competent woodworker that can make them. To be honest, for the last 6 months I've sort of been on vacation and worked on more personal goals. That included getting in shape and doing some mountain bike racing in Aspen and Crested Butte this summer. Most competent wood shops around here are backlogged with residential projects as Colorado is growing and housing is getting expensive so I may need to look at some other options on the coasts.

It's basically a LeCleach horn that covers 400-15,000 Hz using a driver with no crossover except a carefully chosen capacitor to reduce excursion. With these kinds of systems you move a lot of work into the driver it's self. It's response must match the horn. Nothing totally unique but it's the implementation and driver that are important, and I think bass/tweeter integration is excellent, of course.

 

[DaveC]

Finally.
Congrats.
Can we see some pictures, please?
Maybe even a separate own thread?

Congrats are a little premature, I still need to finish the final cabinets.

It's difficult to find a craftsman to work with on this but it'll happen sooner rather than later. When the cabs are done I'll definitely share photos and more info.

 

[Folsom]

Just because marketers misuse the term "time-alignment" doesn't mean it is nonsense or that it is not the same as a perfect impulse response. The term time-alignment means that all drivers in a speaker are delivering their impulse to your ears or the microphone at the same time, without delay. Another way to look at htis (more accurate, IMO) is the step response. When a speaker is truly time-aligned then the step signal in will give a triangular response out. This is because the speaker cannot hold the "step" and the output drops off. If all signals from the step arrive at the same time then the leading edge of the triangle will be sharp and all going the same direction. It is funny to see a step response with the tweeter or midrange going negative on the step. Clearly there is not time alighnment this way with all drivers move forward together in unison. Impulse response is messy with other issues but can still tell if things are basically going the right way.

I believe I can hear this as I have preference for time-aligned speakers and full-range drivers (particularly electrostatic drivers). Also, my experiments with DSP and demos I have heard once a speaker was time-aligned are pretty convincing that this can be heard.

Trying to align it so impulse/step-response (same thing if you're measuring off the speaker alone) is lined up is just playing with phase. You win some and lose some by trying to set different drivers at slightly different timing through DSP. Physically doing it gains the most claims for advantages but there are other things happening that aren't accounted for so "time alignment" is awarded the prize. If it was all such a huge deal Magico wouldn't be heralded as a good company in any way. They have tweeters in front of the woofers on every speaker but their ultimate.

If you want a cleaner response you basically are just making sure your box doesn't hold a bunch of energy. To do this it may not have anything to do with moving drivers forward and back, even if that could possibly help. It isn't alignment, it's just making sure everything dissipates in a relatively good manner so drivers are not singing well past the signal, while others are not.

 

[audioquattr]

Trying to align it so impulse/step-response (same thing if you're measuring off the speaker alone) is lined up is just playing with phase. You win some and lose some by trying to set different drivers at slightly different timing through DSP. Physically doing it gains the most claims for advantages but there are other things happening that aren't accounted for so "time alignment" is awarded the prize. If it was all such a huge deal Magico wouldn't be heralded as a good company in any way. They have tweeters in front of the woofers on every speaker but their ultimate.

If you want a cleaner response you basically are just making sure your box doesn't hold a bunch of energy. To do this it may not have anything to do with moving drivers forward and back, even if that could possibly help. It isn't alignment, it's just making sure everything dissipates in a relatively good manner so drivers are not singing well past the signal, while others are not.

Have you find out all yourself by trying and testing it? I mean not just place a tweeter a bit behind so it is align but fully adjustable.