THE IMPORTANCE OF TIME DOMAIN RESPONSE MUST READ


Speaker designers ignore or downplay the importance of TIME. Why?

A high end speaker should be as accurate as possible and that means it should not only be optimized with regard to frequency response but time response.

Back in the 70’s and around that time, speaker engineers thought that a perfect speaker would be one that had a flat response. This idea has waxed and waned in popularity over the years and even now there is no consensus.

What the speaker engineers forgot to consider is Time response.

The time reponse of a speaker is how fast it starts and stops. A perfect speaker would have a perfect time response of 0. Since this is not possible, we must get as close to it as possible. The problem is speakers engineers have neglected this aspect of the design and so speakers over the last 40 years have not improved in this respect.

Time is such an important aspect of the sound we hear. We not only hear tone but also time. The brain can detect time differences of only a few microseconds. Experiments have shown that the start of each note is what we use to determine what instrument is producing that sound.

We must ensure that our crossovers do not smear the time response because it will be heard by our ears. Time inaccuracy is why high end speakers do not sound like real instruments.

Diffraction from the cabinet can also cause time smear. We need spherical cabinets not square boxes. Tweeters need to be time aligned in order to ensure that when the woofer stops so does the tweeter. When the woofer starts, so must the tweeter. The woofer itself has to have a Qts of ZERO to prevent time smear. Ports must not be used or else you will get ringing.

We need to make it mandatory for speaker companies to publish the time response of all their speakers so that consumers can easily compare and decide exactly what they want. Some may actually prefer a speaker that has a poorer time response and that is fine. The problem is, we cant decide unless we know what we are buying can we?

Unfortunately, 90% of speakers on the market, even high end speakers have ports. And they are also made of cheap wood, even though there must be better materials by now. Some materials ring more than others.

So dont be deceived folks. If you want better speakers, you will probably have to make them yourself because speaker manufacturers dont care about sound quality. They spend millions of dollars on anechoic chambers all so that they can get a flat response but they spend zero effort on better time domain response. We are being duped.

kenjit

Showing 7 responses by perkri

Fritz doesn’t use capacitors in his crossovers.

Once again kenidjit strikes out. He uses the acoustic reality series crossover. One of the reasons why his speakers measure so well, and how they provide an easy, and consistent  load for the amplifier to see. 

Surprised you don’t know about this crossover, seeing as you are such a great speaker designer and superior audiophile.

 

“A scoffer like you would not believe me even if I did state what I listen to.”

 

Try us all, Bozo…

 

 

@erik_squires 

 

From what I understand, he uses the ARSXO, which he acknowledges (as is required because of the patent held, which was made open provided anyone who used it in a commercial venture credited the circuit/inventor) The classic version of this crossover has one resistor, two inductors and of course the drivers in a two way wired in series. I know there is a version of this crossover out there that includes a single capacitor, but that is not the circuit he links to in his description? 
 

If you know otherwise, please elaborate as I would be very curious to know more!
 

And yes, more often than not, speakers use parallel crossovers. Much easier to tune a speaker that way. Each element can be isolated with greater ease. Change one thing in a series crossover, and you change more than one thing. Not as easy to isolate a problem. 
 

I’ve spent a fair amount of time over the past year or two trying to better understand the ARSXO, and have built several speakers using it. Have even managed to convert some diy friends after A/B comparisons using the ARSXO and the manufacturers crossover supplied, or, recommended crossover to be built. 
 

No capacitors, just those three parts.

 

But I would honestly be interested in learning more about Fritz and if/how he implements the caps.

 

Thanks!

 

p

@erik_squires 

 

Sorry, should have been more clear :) When using the ARSXO, I am struggling to see what purpose a cap would have on the woofer, and how it would be implemented. In a more traditional Cap/Res/Ind series or parallel crossover, sure, use of a cap is not a mystery. Just not in the ARSXO. Would love to see how that is done! Always wanting to learn new stuff…

@timlub 

 

Im a minimalist for sure :) Building a speaker for a friend, that is specifically intended to go into a shelf in a Ikea kallax shelving unit. 335mm cube. Not fun… So, small sealed full range driver and the rest is for a band pass sub. The boxes are doing most of the work, and the drivers were chosen for their suitability in the boxes. Even so, there are six components on the FR driver just to manage it. There are no”crossover” parts per say as the drivers/enclosures are doing the high pass/low pass work. But I digress :) Guess that was to illustrate how I very much prefer fewer parts.

@erik_squires 

 

Thanks for that! So happy to hear Fritz is a nice as I have imagined from everything I’ve read. I’ve considered reaching out to him, but never been comfortable asking technical advice from a manufacturer/anyone in the industry  I don’t know. 
 

As far as caps in his circuit, I was going by the links and what he wrote about his crossovers. I’d be curious what purpose a cap would serve in a crossover beyond protecting the tweeter. Unless it’s being used in a Zobel network on the woofer?

@timlub 

While it works like a series crossover, don’t know I would refer t9 it as simply a series crossover. If it were, the designer would not have been able to get a patent on it. I’m a big fan of the approach. Have a way to go with getting a better understanding of its implementation (which is why I have wanted to reach out to Fritz), but seeing as how there is a commercial product I’m working on at the end of this, didn’t feel it was appropriate. 
 

Too bad this conversation has to happen in between the kenidjits ridiculous self aggrandizing rhetoric…

 

@erik_squires 

 

Thanks for the link!

 

Been on that site a few times, but never in that section.

 

Ill be checking it out.

 

p