Great video. The video description reads “Time aligned speakers were once all the rage. PS speaker engineer Chris Brunhaver explains why they don’t work and never did.”
Should that be updated to mention passive crossovers?
I think people at Dynaudio, Genelec, Kii Audio, Dutch & Dutch etc might disagree when it comes to their DSP speakers.
You gently touch on DSP at the end but perhaps should have emphasised more at the start that the bulk of what you were saying applies to passive crossover speakers?
Look forward to more speaker videos from you.
Thank you! Yes, that’s a good point. The comments were mostly regarding speakers with passive crossovers, which is 95%+ of the high end audio market.
I’m just getting started with the video stuff and will attempt to be more coherent and simpler in future videos.
Yes, the speakers that you mentioned (and other DSP speaker like Meridian) have high order linear phase crossover or DSP correction.
Dynaudio still does a lot of passive crossover speakers and I believe has notable moved away from 1st order filters to high order in the fairly recent past.
I think that the Kii and Dutch & Dutch are more interesting, not for their phase behavior but because they target a caridioid radiation pattern to a fairly low frequency (each through different means). But that may be an good topic for another video.
A lot of the know how here at PS Audio would lend itself to active speakers but a large chunk of the market is still best served with passive designs, so we are starting basically there (but with an active woofer section to side step some of the box size/efficiency trade-offs).
It would be interesting to see a discussion between Richard Vandersteen and Chris.
@Chris_Brunhaver love the vid dude. I’m an amateur speaker builder so as far as I’m concerned you’re the star at PSA. Those amp and DAC dudes are small potatoes
I deliberately didn’t mention Meridian in the context of this time coherence discussion.
Meridian DSP8000 digital active loudspeaker Measurements part 2 | Stereophile.com
From Stereophile’s review:
Noted but I only mentioned their DSP speakers. One example showing they know what they are doing with DSP crossover design:
Dynaudio Focus 200 XD powered loudspeaker Measurements | Stereophile.com
This review was form 2001 and things have changed substantially in their product line and software and platform, so I’m not sure that you are still right about that.
In a later software/firmware update, they added correction the phase of the woofers (which are normally minimum phase and so the phase rotates as they roll off) so I’d be surprised if this didn’t include other aspects of the system, if they found it beneficial at low frequencies (where we are more sensitive to intensity differences than time differences).
Two days, two videos from @Chris_Brunhaver. Here is what I’ve learned: Chris has time to make videos so the FR-30s are basically done
Thanks Chris. The point of that example wasn’t to say Meridian have never produced a time coherent speaker (I never said that).
The interesting point to me is the part I had highlighted… that Bob Stuart deliberately thought his flagships sounded better non-time coherent. Why they changed their mind in a later firmware update, only they know but that’s a different story I guess.
@Chris_Brunhaver loving the videos dude. Don’t know if you like making them but a lot of us like watching them. Pretty soon you’ll be more interesting than that other guy
Thanks man. I have to work to do with engaging with the camera more and will try to connect better with the audience. I have a lot of respect for Paul, as I have a hard time speaking off the cuff about a technical topic while being conversational and interesting. It would help to have someone in the room with me, but I’ll get over it.
Today’s video was a step up from the others so you’re getting there. I’m sure it’s weird talking to an inanimate object lol. But it’s probably like anything else - practice and it becomes second nature. I bet the first few videos Paul ever did were painful. He was probably sweating bullets lol.
You’re right. I was sweating bullets and awful.
He’s doing great, right guys? Loving this and he gets better and better. Gonna kick my booty soon enough.
Yup. Loving the vids. I assume you’re spending your new found free time with the pizza oven lol?
Next thing you know you’ll be spending your weekends at the office recording videos! Just say no.
Great job, enjoying the insight into speakers et al
I love hearing you Paul. But I can imagine the effort to record Is almost a full time job itself. If Chris can help share the load, that’s a win-win IMO & gives us viewers even more options to learn and hear experience/expertise/perspective from the PS Audio family.
Is the DSP on the FR30 allow adjustments over the entire frequency band or is it limited to those frequencies controlled by internal amp/woofer? Or is this a stupid question.
I like the way Paul reads out the user question: “John from Manchester writes… Hey Paul…”
It makes it feel more personal for those that wrote the question.
You should do the same!
Edit: I see in your latest video you did that. Cool !
Thanks for the suggestion! Yes, I’m going to adopt that in all of the videos moving forward.
We have talked about doing some videos that are more general topics, as opposed to answering a specific user question.
One of the ideas is to do a series of videos showing a DIY speaker design, walking through the design process step by step.
I think that the idea would be not to show the driver design process (maybe just touch on it a little) and use something off-the shelf and use freeware or inexpensive design and measurement tools.
Thanks going to take a lot more work than our off-the-cuff Q&A but might be interesting to some, as we get a lot of questions on crossover design questions.