JBL Master Reference Monitor

[Mr. Widget]

OK, I've said it...

I haven't seen them yet, but I get it. Talking with our JBL rep recently they were discussing their use in behind the screen applications.


Widget

[timc]

Nope... I don't know anything about their products. I did just checked out their web site. Superficially their speaker management product seems somewhat similar to the DEQX system.

What do you know about their products?


Widget

I have met the developer, and worked with one of his colleagues. The BIG difference is that you can buy the FourAudio as an OEM module. This means you make your own PSU. The board also has extra digital I/O lines, so you can use the onboard AD/DA, or you can make your own. It takes I2S, SPDIF and AES/EBU connection. I'm in the process of putting one together for a friend. I have big expectations.

[pos]

Four Audio also sell their technology as a finished product: the HD2 processor.
Here is an AES paper from 2007 where Rainer Thaden explain most of the design aspects and strategies used in the HD2: http://www.studitech.ru/resque/manua...ES32_rev-5.pdf

This processor was really ahead of its time, thanks to its downsampling (decimation) strategy that let it manage great resolution in FIR processing despite relatively low power DSP (by today standards).
The converters are also very good so it should not intrude too much when used inside an analog chain.
Not sure the user has a full access to the FIR parameters without using their proprietary (and very expensive) software though...

Before the HD2, Four Audio also build the FIR crossovers of the K+H (now Neumann) active monitors and pro c28 processor.

[timc]

Four Audio also sell their technology as a finished product: the HD2 processor.
Here is an AES paper from 2007 where Rainer Thaden explain most of the design aspects and strategies used in the HD2: http://www.studitech.ru/resque/manua...ES32_rev-5.pdf

This processor was really ahead of its time, thanks to its downsampling (decimation) strategy that let it manage great resolution in FIR processing despite relatively low power DSP (by today standards).
The converters are also very good so it should not intrude too much when used inside an analog chain.
Not sure the user has a full access to the FIR parameters without using their proprietary (and very expensive) software though...

Before the HD2, Four Audio also build the FIR crossovers of the K+H (now Neumann) active monitors and pro c28 processor.

The control software is free. It is included with purchase of any variant of their hardware.

[pos]

I was under the impression that their "Monkey Forest" software (2500€ excl tax) was needed to manage the FIR capabilities of the HD2 and modules.
Is this free software you are talking about a derivate of Monkey Forest?
Can you load arbitrary FIR coefficient? How do you handle the decimation/downsampling process?

[4313B]

Very interesting... can you elaborate?

Yes. In short, HCSGuy can have five supermodels sitting to his left and five supermodels sitting to his right and all of them will share the same listening experience.

They're Ugly

You're surrounded by supermodels, how loudspeakers look shouldn't be an issue.

I'm used to the 4430/4435 so the M2 fits right in with the theme. And as has been said, Consumer wanted to sell them as LCR in a large HT setup, perf screen, etc. Sooner rather than later.

G.T. just responded that ML was not working on a DSP engine to go with the rest of the M2/ML gear.

And we'll have to wait and see if this tech actually does filter down through Consumer and whether or not we get some stylish specimens.

"Monkey Forest"

Good grief...

My confidence in their product just dipped a hundred points.

Nope... I think they have moved in the right direction, but I haven't heard anything that has given me the confidence to try it again.

You and G.T. might be too high up the chain. He's very interested but his confidence is low with respect to current offerings.

[timc]

Good grief...

My confidence in their product just dipped a hundred points.

Well. If we are to look at names only. Then Everest and K2 can be considered fairly pretentious

Their knowledge into DSP is quite extensive. They are particual into Wave field synthesis : http://fouraudio.com/en/references/w...synthesis.html


Pos. There is a separate control software for the HD2 module. The downside is that it cant do the actual measurement. You have to do the measurement, and then load it into the HD2. At least it is like this for the OEM modules.

Here is some technical details: http://www.four-audio.com/data/HD2-S...asurements.pdf

[4313B]

Well. If we are to look at names only. Then Everest and K2 can be considered fairly pretentious

Can't do that with the Everest II anymore and expect people to know what you are talking about, what with a DD65000, DD66000 and DD67000 out in the wild.

I'll pass this info along to G.T. and see if he wants to give them a try. Thanks!

[pos]

Pos. There is a separate control software for the HD2 module. The downside is that it cant do the actual measurement. You have to do the measurement, and then load it into the HD2. At least it is like this for the OEM modules.

What do you load exactly? FIR coefficients?

[grumpy]

From the manual:

"With the controls in the FIR Filter groupbox, FIR filters can be downloaded, uploaded and activated.
After establishing the connection, the drop-down lists are filled with the filters present in the HD2. At the
time of writing, the filters can only be generated with the software Monkey Forest."

Perhaps this capability exists outside of MF and the obligatory test set by now?
As it is, it seems very much like the older BSS products (plus the four-audio unique
A/D and limiter capabilities).

Price on the 2x4 modules?

[ivica]

From the manual:

"With the controls in the FIR Filter groupbox, FIR filters can be downloaded, uploaded and activated.
After establishing the connection, the drop-down lists are filled with the filters present in the HD2. At the
time of writing, the filters can only be generated with the software Monkey Forest."

Perhaps this capability exists outside of MF and the obligatory test set by now?
As it is, it seems very much like the older BSS products (plus the four-audio unique
A/D and limiter capabilities).

Price on the 2x4 modules?

Unfortunately exact format of the file is not presented in the manual.

I understand that :

"....FIR filters can be downloaded, uploaded and activated......It generates two binary files named <filtername>.blk and <filtername>.fcs. The .fcs file contains information about the filter to be displayed in the GUI. As soon as a filter is uploaded to the HD2, it is newly formatted to reside in only 1 file with the suffix .fir. You can either upload the .blk file (if the corresponding .fcs file exists in the same directory) or upload a .fir file......."

but I think it is not enough to 'construct' mentioned files, even you exactly know the values of the FIR coefficients...

Regards
Ivica

[pos]

Thank Grumpy.
If the format they are using for the FIR coefficients (and possibly decimation parameters? or maybe is is automatically set based on sampling freq) is published, then I could modify rePhase to generate it (current output formats include wav, txt floats, and IEEE-754 32bit floats to fit the openDRC/miniSHARC plateform).

Price on the 2x4 modules?

I was quoted 645€ (excl tax) last year.

[timc]

I payed 950 EUR +VAT last year. for the 2x8 module.

I might be misinterpreting what you mean Pos. According to Rainer, you uppload your measurement to the HD2 with the free software. Then define your target response, both frequency and phase, and then it automatically does the necessary adjustments.

[cooky1257]

Don't kill me.....but virtually everything you play these days will have gone through DAW's in the recording/production stage(probably several).
Awareness of what the 'original' should sound like is sketchy at best so I'm curious just how important is it to wring out the very last gasp of subjective transparency in the DSP when it will in effect be modifying the output as part of it's function....

[timc]

Don't kill me.....but virtually everything you play these days will have gone through DAW's in the recording/production stage(probably several).
Awareness of what the 'original' should sound like is sketchy at best so I'm curious just how important is it to wring out the very last gasp of subjective transparency in the DSP when it will in effect be modifying the output as part of it's function....

It's a fair point. The way i see it we have two options.

1: Just assume that what is on the record is the "answer". That means that our system must bring that into the room as uncolored as possible. Then absolute transparency is the goal.

2: Realize that we can't know the exact conditions in which the mastering was done. We can also assume that the monitors used were not perfect. Then we can follow your reasoning and just tune it to our subjective liking.

Imo both methods have their merits. Personally I am in camp number 1 for the time being.