1st Order Crossovers and Dynaudio

[ridikas]

I'm a very big fan of the Dynaudio sound, especially their Contour series and above. In fact, the Confidence are some of my favorite speakers of all time.

Dynaudio is a big proponent of the 1st order crossovers. I've never taken one of their speakers apart, nor have I ever measured one myself. I did see quite a few pictures of their crossovers online and they look fairly sophisticated. Much more so than just a capacitor on the tweeter and a coil on the woofer.

Does anyone here know if Dynaudio actually goes through all of that trouble to achieve true 1st order acoustic slopes?

What are some advantages and disadvantages in doing so? Any DIY examples that feature true 1st order slopes?

Dynaudio surely knows how to make a wonderful sounding speaker.

[Pete Schumacher]

Re: 1st Order Crossovers and Dynaudio

I'm a very big fan of the Dynaudio sound, especially their Contour series and above. In fact, the Confidence are some of my favorite speakers of all time.

Dynaudio is a big proponent of the 1st order crossovers. I've never taken one of their speakers apart, nor have I ever measured one myself. I did see quite a few pictures of their crossovers online and they look fairly sophisticated. Much more so than just a capacitor on the tweeter and a coil on the woofer.

Does anyone here know if Dynaudio actually goes through all of that trouble to achieve true 1st order acoustic slopes?

What are some advantages and disadvantages in doing so? Any DIY examples that feature true 1st order slopes?

Dynaudio surely knows how to make a wonderful sounding speaker.

There's only one advantage that comes to my mind to a 1st order acoustic slope, and that's "transient perfect" designs. However, that only occurs at one location, and the trade offs are poor power response if the drivers are not coincident, and lower power handling for the tweeter.

Edit: should have said lobing instead of power response

[carlspeak]

Re: 1st Order Crossovers and Dynaudio

Study some of John K's 1st order modeling of power response. He's a smart guy. Therein may lie some answers to your questions.

http://www.musicanddesign.com/Power.html

OTOH, my Intimates have 1st order elect slopes and sound and measure wonderful. However, the drivers used in them are of high quality and pricey. Many classic designs have 1st order slopes. They were designed back in the day when drivers had very good response characteristics and didn't require a mortgage to buy them. Many of today's bargain and moderate price drivers require some level of 'jumping thru hoops' to overcome their response deficiencies.
Thank God for PCD.

[gregbegland]

Re: 1st Order Crossovers and Dynaudio

I'm a very big fan of the Dynaudio sound, especially their Contour series and above. In fact, the Confidence are some of my favorite speakers of all time.

Dynaudio is a big proponent of the 1st order crossovers. I've never taken one of their speakers apart, nor have I ever measured one myself. I did see quite a few pictures of their crossovers online and they look fairly sophisticated. Much more so than just a capacitor on the tweeter and a coil on the woofer.

Does anyone here know if Dynaudio actually goes through all of that trouble to achieve true 1st order acoustic slopes?

What are some advantages and disadvantages in doing so? Any DIY examples that feature true 1st order slopes?

Dynaudio surely knows how to make a wonderful sounding speaker.

Surely with your speaker building prowess, you understand that there can be much more to a 1st order crossover than just a cap and coil....

Have a look at those Vandersteens you asked about previously, they have high parts counts for begin just a 1st order slope.

Greg

[ridikas]

Re: 1st Order Crossovers and Dynaudio

^^^^ Isn't that exactly what I said to begin with??

[daryl]

Re: 1st Order Crossovers and Dynaudio

^^^^ Isn't that exactly what I said to begin with??

Patience Obi-Wan.

At first glance someone could see you're name and think it's 'Rediculous'.

You don't want to make folks think they had it right the first time.

[daryl]

Re: 1st Order Crossovers and Dynaudio

Dynaudio could achieve some impressive things with thay're drivers back in the day when DIY'ers could get them.

Tweeters with the highest low frequency capability in the industry and woofers with amazing dispersion right up to their rolloff.

The crossovers on the other hand were not what they claimed.

They had first order electrical filters with allpass filters built in to them to compensate phase.

In effect you get the phase shift of a higher order filter with the slow cuttoff of an 1st order filter.

The worst of both worlds in a manner of speaking.

[ridikas]

Re: 1st Order Crossovers and Dynaudio

Daryl - Is there a reason why Dynaudios sound so good? Or is it just my preference/imagination?

P.S. - Dynaudio has an actual lattice style filter in their crossover network?

[Jeff B.]

Re: 1st Order Crossovers and Dynaudio

There's only one advantage that comes to my mind to a 1st order acoustic slope, and that's "transient perfect" designs. However, that only occurs at one location, and the trade offs are poor power response if the drivers are not coincident, and lower power handling for the tweeter.

Actually most Transient Perfect designs typcially have flat power response through the crossover region, as opposed to in-phase crossovers that have a 3dB dip.

However, we need to remember that most speakers with first order electrical crossovers are not transient perfect designs. This combination of time, phase, and frequency response characteristics is actually pretty honkin difficult to achieve. Now, once achieved it is no more limited to "one location" than any other type of crossover is, all of them sum differently on another axis. But, the transient perfect design will still be minimum phase on the other axes too, which these other designs will not do. (I remember arguing the opposite position a few years ago with Jay Kim, and being proved wrong. It helped me see this in a new light.)

My new Transient Perfect design offers a rather interesting acoustic crossover that asymptotes in some fairly steep slopes, but remains minimum phase. But I won't go into details yet, since it will be a commercial kit.

[daryl]

Re: 1st Order Crossovers and Dynaudio

Back in the day it could really get my motor running thinking about an MMT or MTM with the 24W100 and D28.

The 24W100 had a 4" voice coil (on an 8" driver!) and natural rolloff at 3khz without a peak and even dispersion right through the rolloff.

The D28 had it's own waveguide with even dispersion to 20khz and strong output at 2khz.

[Jeff B.]

Re: 1st Order Crossovers and Dynaudio

Dynaudio has an actual lattice style filter in their crossover network?

Yes, they do. But the problem is that these all-pass delay networks do not produce a constant delay with frequency and always add excess delay as you move from the crossover point. They can be beneficial to help "phase align" at the crossover point, but they are not effective to "time align" two drivers. Physical off-setting of the drivers is still the best way to do this.

Dynaudios still sound very good. It probably has to so with the very smooth response of their drivers and the fact that they can integrate them with simple networks. I prefer simpler networks whenever I can use them.

[daryl]

Re: 1st Order Crossovers and Dynaudio

Daryl - Is there a reason why Dynaudios sound so good? Or is it just my preference/imagination?

P.S. - Dynaudio has an actual lattice style filter in their crossover network?

They often used lattice allpass filters, yes.

Don't know why you like them but there's a lot things it could be.

[Jeff B.]

Re: 1st Order Crossovers and Dynaudio

Back in the day it could really get my motor running thinking about an MMT or MTM with the 24W100 and D28.

The 24W100 had a 4" voice coil (on an 8" driver!) and natural rolloff at 3khz without a peak and even dispersion right through the rolloff.

The D28 had it's own waveguide with even dispersion to 20khz and strong output at 2khz.

I know. Remember Joe D's orginal MTM and his argument for the D28 as the best tweeter available? I was drooling for a pair. I was so excited when I finally built a full Dynaudio three-way tower with dual 12's in an aperiodic 5 cu ft enclosure. I was drinking the cool aid! Sometime, I wish I had those speakers back. ;)

a few years ago I gifted Wolf with a pair of NIB D76AF's. I'm still waiting to see what he tries with them.

Jeff

[ridikas]

Re: 1st Order Crossovers and Dynaudio

So to time/phase align the drivers one can use one of the following methods:

1.) Offsetting the drivers by a physical distance. Is this agreed upon as the best method?

2.) Using an active setup and crossover.

3.) Using a lattice style all pass network.

4.) Using asymmetrical slopes. (i.e.) Shallower slope on the woofer. Does this even work?

Am I missing anything?

[Jeff B.]

Re: 1st Order Crossovers and Dynaudio

So to time/phase align the drivers one can use one of the following methods:

1.) Offsetting the drivers by a physical distance. Is this agreed upon as the best method?

2.) Using an active setup and crossover.

3.) Using a lattice style all pass network.

4.) Using asymmetrical slopes. (i.e.) Shallower slope on the woofer. Does this even work?

Am I missing anything?

You're missing the fact that time and phase alignment are two very different things in crossover design, and you're mixing them together.