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[ANNC] eBook on Accurate Sound Reproduction Using DSP

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Hello, I wrote an easy-to-follow step-by-step guide for designing a custom digital filter that corrects the frequency and timing response of your loudspeakers in your listening environment so that the music arriving at your ears matches as closely as possible to the content on the recording.

To view the Table of Contents and read the first few chapters, click on the cover image "Look inside." https://www.amazon.com/dp/B01FURPS40/

Enjoy the music!

Mitch
 
Yes, very helpful, thanks Mitch.

I'm halfway through the book, enjoying it very much. Congrats! I have been intimidated by the power and complexity of Acourate, and heardstories about the steep learning curve, etc. So your book is clear enough instructions to let me give Acourate a try.

I used the book's advice about B&K curve to adjust my passive crossover, tilting the tweeter down a couple dB by increasing the parallel resistor, made a really big improvement in listenability without sacrificing the tone detail.

Another pointer for me to follow this direction is that my wife recently got a BMW with "Harmon Kardon" audio upgrade. It is dsp active, all dialed in to perfection. The band is floating out in front of the car with perfect imaging, perfect tone, deeply satisfying musically. It is an amazing listening experience, and makes me want that kind of sound in my home stereo. I've tried traditional hifi technique even with big budget without ever sounding that good.

I have used budget pro audio multichannel interface with JRiver dsp studio to make active system, but the interface SQ was not enjoyable. I had tried speaker management boxes like Rane and Behringer but they were either poor SQ or unreliable. DEQX sounds great but out of my budget. DIY Buffalo 8ch DAC had no I2S source that was low enough jitter. I knew about Acourate, AudioLense, rePhase, etc, but I hesitated because there was no inexpensive multichannel DAC with low jitter and audiophile sound quality. But last week I saw post here from diyinhk about their new multichannel XMOS USB>I2S adapter and mating 8ch ESS DAC. I have used their stereo USB adapters before, they are excellent. That should make a fine DIY computer audio interface for high end speakers. I ordered the pair today for $170 shipped! Still need ADC and Acourate, but I'm looking forward to trying it. Thanks for the guidance in the book.
Rich
 
Hello Richidoo,

Thanks! Yes, to both of your questions. In the book is a step-by-step walkthrough of a 3-way digital crossover stereo speaker system. While it is not a novice book, it does explain the technology with examples, plus links to reference material that assists with the explanations. Hope that helps.

Kind regards, Mitch
Hi Mitch,
I'm looking for a definitive step to step guide for my PC-based 4 way active system. Might your e-book to be the solution or is it only useful for 3 way systems?
Regards
Antonello
 
Hi Antonello,

Sorry for the delay, traveling on business.

Yes, the step by step guide will work for a 4-way active system as well. You will see the pattern. Note one of the book reviews is from Pierre O, who also has a 4-way active system.

Kind regards, Mitch
OK, many thanks Mitch for the kind reply!
Hoping to have early a step response like your I will book as soon as possible a copy of your e-book and a license for Acourate.
Kind regards
Antonello
 
Mitchba, it is great that you share your view and experience with us through the book.

Recently, I am considering replacing my uncle's obsolete Krell active crossover and just wondering how to make a digital crossover for him. I saw this thread yesterday and bought your book immediately.
 

jpak

Member
2007-06-12 6:02 pm
CT
I've read over your CA article a few times and will pick up the book soon. My question is about using Acourate for digital crossovers. The Wilmslow K100 (sort of an ATC SCM100 clone) kit I was planning to build includes passive crossovers that are presumably similar to ATC's retail models that have decent pattern control at the crossover points. I was considering using Acourate to do all the digital crossovers and tri amping.

In your CA article you mention linearizing the drivers by measuring from 30 cm away. Between the bass/mid is this sufficient to make floor bounce a non-issue? Or would it be more ideal to measure outside with speakers raised up? And is a single measurement from 30 cm sufficient or would off axis measurements at 15, 30, 45 degrees improve the linearization?

I'm sure it will make more sense when I have hands on experience with the app, thought I would ask anyway. Thanks :cheers:
 
Hi jpak,

Yes, ideally, one would linearize the drivers outside with speakers raised up. However, in my case of speakers weighing 150 lbs each and no where quiet outside, I ended up linearizing then in-room. In my eBook, I measured them 10cm away on axis and for sure, linearizing the woofer is going to include room effects. In my specific case, linearizing the woofers produced a better overall result than not. It is an experiment to try.

There is a caveat, and quick to find out if it is worth linearizing or not as it is an optional step. If the driver measures +- 2dB through its passband, in a near field measurement, then linearizing won't buy you much. In my specific case, I use compression drivers and waveguides, which typically have a little more ragged frequency response in favor of efficiency, so it was worth the effort. It may very well be that the Wilmslow K1 use much smoother drivers and you can bypass this optional step. A quick near field measurement indoors will validate whether you need linearize or not.

I use constant directivity waveguides, so no need to measure near field off-axis, which I did try and the fr result is as expected. Basically one is at the mercy of the polar response of each individual driver. Using linear phase digital XO's, which I highly recommend, will have minimal effect on the pattern control through the XO as the XO slopes are steep and both the amplitude and phase response sum perfectly as can be seen in the article you read.

Hope that helps.

Kind regards, Mitch
 
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