JBL Master Reference Monitor

[Mr. Widget]

I am leaning towards the blue baffle retro look, including hiding the ports behind the blue cloth grille. Most likely the good old black walnut veneer as well.

I can almost smell the sawdust! Damn... that sounds good.


Widget

[sebackman]

Hi,

I think the baffle edges are quite important here since the waveguide is rather wide. In the M2 the edges of the waveguide are the really covering the edges of the cabinet. From my thinking, the simplest way would be to design the same type of cabinet as the original(albeit with different dimensions), i.e. let the side walls and lid end a few cm out from the baffle to meet the waveguide outer edges (sides and top).

Since the baffle will be recessed for the woofer compared to the sides, JBL added an additional “baffle” beneath the woofer only. Probably to reduce reflections and cancelations from the side walls. The waveguide is also molded to fit on top of the additional woofer baffle with a rounded edge.

I had some significant problems with a 2206 in a SR4722X cabinet with the same “overhanging” sides. I solved it by making a distance ring to move the woofer out from the cabinet, so the extra baffle is probably a must.

So when using two woofers I think a column would be better or side by side but with the waveguide in a narrower cabinet on top.

[4313B]

I think we are on the same page.

I went back and modified my 4338/4365 enclosures the same way, cutting a 45 flush with the baffle and doing away with the sides that recessed the baffle.

I need to get AutoCAD reloaded on a PC and do some drawings. I used to get significantly more excited about this stuff and would have had AutoCAD already reloaded in anticipation.

Here are some photos that were provided to me if someone wants to draw up plans. I believe the tech sheet has also been posted and is readily available from Pro showing the exploded view.

One dimension that could be of great interest would be the internal front to back dimension. Heck, all three internal dimensions would be great but that is understandably a lot to ask.

[macaroonie]

[4313B]

For some reason I forgot all about that. Thanks!

[macaroonie]

I knew it would come in handy sooner or later. You are most welcome.

[cooky1257]

Can't help thinking those ports would look better on the back with a perhaps a deeper grill running from beneath the WG to a 30 mm edge along the bottom... .

[Mr. Widget]

Can't help thinking those ports would look better on the back with a perhaps a deeper grill running from beneath the WG to a 30 mm edge along the bottom... .

If they ever come out with a consumer version I would imagine the design would be along those lines... but it would also cost quite a bit more and have their cheap looking veneer on it. B&W and everyone else seems able to use nice veneers on their higher end models... but currently JBL only offers these finishes on the Everests.

Rant over.


Widget

[Valentin]

I fund out that BSS has a London DSP that has no Fan
the BLU-50. It's a 4 in 4 out processor
so for a stereo project its ideal

[Mr. Widget]

I fund out that BSS has a London DSP that has no Fan
the BLU-50. It's a 4 in 4 out processor
so for a stereo project its ideal

We've been using the Synthesis SDEC versions of the BSS BLU processors with their fans disconnected for years with no issues. We do have them in an open rack with plenty of airflow.


Widget

[sebackman]

Hi,

JBL seem to use the BSS BLU32 and the BLU 80 rebadged to SDEC. They, together with the BSS BLU16 are quite noisy with only one or two fans.

The BSS BLU160 (I think) and the BLU800 (I know) seem to run colder (maybe newer dsp chips) and uses 4 fan's which is much quieter. They also have 4 times the DSP engine power to run a multi-channel HT system with an output expander. –Even at 96kHz processing. I use 8 channels digital input (SPDIF 24bit/96kHz) and 16 analog output channels (3-way 5.2) on my BLU800 & BLUBOB.

The new BLU50 as mentioned above is also a good choice as it can be expanded to more output channels (no more inputs) and has twice the DSP engine of the SDEC’s

Kind regards
//RoB

[Mr. Widget]

I think you are referring to older SDECs like the 3000 and 4000. The current models like the 4500P, 3500, and 4500X (the expander model) have four fans and tons of processing power. They are still noisy though. These are the units that we are running with all four fans disconnected. We were told that while JBL couldn't endorse disconnecting the fans, in our well ventilated rack there wouldn't be a problem... and there hasn't been one.

These newer BSS/SDEC processors are not only more powerful, but they are also sonically superior to the older units.


Widget

[Valentin]

I think you are referring to older SDECs like the 3000 and 4000. The current models like the 4500P, 3500, and 4500X (the expander model) have four fans and tons of processing power. They are still noisy though. These are the units that we are running with all four fans disconnected. We were told that while JBL couldn't endorse disconnecting the fans, in our well ventilated rack there wouldn't be a problem... and there hasn't been one.

These newer BSS/SDEC processors are not only more powerful, but they are also sonically superior to the older units.


Widget

Thanks for the input on the fans on the bigger Sdecs/blu.

but if your system is stereo the BLU50 is the deal. You wouldnt need more outputs its half price blu 800

Get some fanless amps

[sebackman]

Hi Widget,

Do you know what JBL SDEC model corresponds to what BSS model?

The older SDEC3000 (and I think the SDEC4000) is a BLU16 based unit with the USB connector on the front.

What is the 3500 based upon and what is the difference compared to 4500?

From the JBL owner’s manual they look the same and spec the same, but the 4500 uses the BLULink to get outputs. If that is the case it is all in the SW, the HW platforms are identical, a BLU160. All BLU160and 800’s have native BLULink HW so if 4500 can do something 3500 cannot it is all SW (if they indeed are the same HW platform).

BSS brand offered the older 2x100MHz (BLU16/80 generation) and the 2x400MHz (BLU160/800 generation) platforms with interchangeable I/O cards.

All the platforms can hold 4pcs I/O cards with maximum 4 single ended or balanced (analog or digital) channels. You can mix the cards as you see fit. Via BLULink you can add more I/O units to a maximum of 256 channels in or out to any one DSP. All I/O cards fits in any unit. All the I/O (ADC and DA) is done on the I/O cards and the DSP processing on the motherboard. All of them use dual SHARC DSP’s. I use 8 digital in and 16 analog out for a 5.2 3-way.

Maybe JBL had BSS make a special for the Synthesis system….

I Agee with Valentin, now they offer the BLU50 a fixed input/output device with 2x200MHz, as mentioned. Only 4 input's fixed but with BLULink so I guess you can add more channels out as needed. Shuld be fantastic with a set of M2's and some ML amps.

On the sound quality, according to BSS the SW updates makes all the difference. All BSS units can be updated to the newest algorithms and unless the processing power is insufficient they should sound reasonable the same. Maybe the older JBL units had older ADC or DA cards but I think the SW is the source. Maybe JBL was not adopting all the newest BSS SW on the older units whereas BSS still does. I have no idea what differs between the JBL propriatary SW and the original BSS.

I have used both BLU16’s, BLU160’s and now BLU800’s and the real game changer is going digital in. They perform real fine also with analog in but one have to use a high signal in and reduce gain on the power amps to get the best out of the ADC’s. Clipping within the units is very rare even with high signal in. They use 24bit/96kHz I/O and 40 bit internal = lot’s of headroom.

With digital in and no ADC conversion at all, I argue that they are completely inaudible. The drawback is that you will have to have the analog volume control after the DSP. -But that is for another thread…

Much about nothing…

As you say the fans can be disconnected or it looks rather easy to swap them for quiet ones.

I have my units in the “machine room” so I don’t really care. :-)

Kind regards
//RoB

[Flaesh]

http://reconingspeakers.com/product/...l-m2-5032754x/
2430, $345 ..