JBL M2 Master Reference system okay for 2 channel home audio setup? ...

[johanwholst]

For my clones, I use a Crown cts 1200 (600w @ 8 ohm) with silent fan on the woofers and a 25w class A (aleph J) on the compression driver. Notice though that with the passive network in the M2 (witch I do not use) a larger amplifier on the compression driver would be needed

But 1200w for the D2 is overkill imo... and most likely for the woofer as well for domestic use
A set of smaller Brystons would probably be sufficient. Isn't the recommended Mark Levingson amps 300w?

[Valentin]

I got these great M2 two weeks ago to be my home reference audio, (future home studio also)
I was totally following the book, I got one Crown I-Tech 4x3500HD to power them.
The good result : out of box they sounded just perfect! all the details, the accuracy, nothing is more or less. They are the great speakers to spot any recording imperfection.

The bad : the amp fans are unbelievable noisy, they are 52db without any load @ 3ft distance and 60db in front of it.
I placed the amp in a closet, in order to minimize the fan noise, which actually did. Then I was able to do an actual 2 hours of listing.
Here are my results, (mixing board was set to 0 unity gain, I-tech amp is set to -25db) beside the sound is perfect, after about 1 hours of listing I felt that this is more than enough. my ears got tired. They needed to get rest after about 1 hour of listing in this volume.
There is noticeable too high distortion or THD, to be used for long hours of listening.Now I decided to return the amp, and look for an alternative amp so I can enjoy listening to the M2.

I will try to get 2 Crown I-Tech 5000HD to see if things will get any better (Which I doubt).
After several phone calls with JBL pro, they advised that I can use any amps I like with BSS Sound web London, but the amps has to be no less than 1200 watts per driver. To me this is next to impossible to find any Hi-Fi or even Studio Amp even close to that number. The only option is use a touring amp like Crown's, Lab Gruppen or similar...

Even Bryston highest wattage mono-block is only 1000 watts, and it cost about $12000 each mono, which will be $46000 for the 4 mono's!!! I think this is way too much.
Even Mark Levinson will cost somewhere close to that with half of that power.

I am sure there is something I am not able to understand, but I really need to find the amp that can handle these monsters!
I need help please

My previous home system was JBL Ti5000 with Musical Fidelity A5, they sounded very nice (not as perfect as the M2) but I was able to keep listening for several hours with high volume without getting tired of listening

Hi Isave

You do not need 1200 watts per speaker that is a fact
I have been using a crown DCI N4/300. and it's more than enough for a 3 m. Listening distance
It all depends the volume you mix with


DCI do have a fan but it is a lot softer than the itech 5000 I also have

JBL has even put out the DCI tune in in their soft ware downloads





If your intention is a two way system you can use a Bss blu 50 which is fan less. And pair them with the amps of your desire Brystons 4b would do nicely and 14b should be vast for most applications


JBL synthesis uses a mark levinson 300watt per Chanel amp in their set up why would you not


By the way Bss units do have a fan only the Bss blu 50 is fan less

[Dave M]

I got these great M2 two weeks ago to be my home reference audio, (future home studio also)
I was totally following the book, I got one Crown I-Tech 4x3500HD to power them.
The good result : out of box they sounded just perfect! all the details, the accuracy, nothing is more or less. They are the great speakers to spot any recording imperfection.

The bad : the amp fans are unbelievable noisy, they are 52db without any load @ 3ft distance and 60db in front of it.
I placed the amp in a closet, in order to minimize the fan noise, which actually did. Then I was able to do an actual 2 hours of listing.
Here are my results, (mixing board was set to 0 unity gain, I-tech amp is set to -25db) beside the sound is perfect, after about 1 hours of listing I felt that this is more than enough. my ears got tired. They needed to get rest after about 1 hour of listing in this volume.
There is noticeable too high distortion or THD, to be used for long hours of listening.Now I decided to return the amp, and look for an alternative amp so I can enjoy listening to the M2.

I will try to get 2 Crown I-Tech 5000HD to see if things will get any better (Which I doubt).
After several phone calls with JBL pro, they advised that I can use any amps I like with BSS Sound web London, but the amps has to be no less than 1200 watts per driver. To me this is next to impossible to find any Hi-Fi or even Studio Amp even close to that number. The only option is use a touring amp like Crown's, Lab Gruppen or similar...

Even Bryston highest wattage mono-block is only 1000 watts, and it cost about $12000 each mono, which will be $46000 for the 4 mono's!!! I think this is way too much.
Even Mark Levinson will cost somewhere close to that with half of that power.

I am sure there is something I am not able to understand, but I really need to find the amp that can handle these monsters!
I need help please

My previous home system was JBL Ti5000 with Musical Fidelity A5, they sounded very nice (not as perfect as the M2) but I was able to keep listening for several hours with high volume without getting tired of listening

Hypex would probably be a nice choice. Clean, low price, no noise, low distortion, high dumping factor. I don't own M2, but I have been using a few different Hypex as home studio amps. Requires a little bit of DIY, though...

[Mctwins]

I placed the amp in a closet, in order to minimize the fan noise, which actually did. Then I was able to do an actual 2 hours of listing.
Here are my results, (mixing board was set to 0 unity gain, I-tech amp is set to -25db) beside the sound is perfect, after about 1 hours of listing I felt that this is more than enough. my ears got tired. They needed to get rest after about 1 hour of listing in this volume.
There is noticeable too high distortion or THD, to be used for long hours of listening.Now I decided to return the amp, and look for an alternative amp so I can enjoy listening to the M2.

Hallo!

Too me, you have the best amp here. Keep it!! There has to be something wrong with your setup.

Why do you set the amp at -25dB? Do you mean Output Level?

Try this....

"I asume you are using the settings for the M2 and using System Architect as well."

On the "Source Configuration" set the Input Sensitivity at 26dB gain and set the Output Level at 0dB. What are you using here? There is "Custom", "26dB" and "32 dB" of Input Sensitivity to choose from.

There is no high distortion or high THD that you can hear. The listening fatigue is due to, maybe, your bad room acoustics or bad recordings.

There is alot of error that can be done with a system like this.

I have Crown MA5000i driving JBL 4365 and it sounds great here. Yes, I agree about the fan noise, it dosen't bother me. My computer on the side sounds the same.

[johnlcnm]

Hi discus96,

This is very, very, very nice JBL collection.

Concerning the directionality "problem" may be the room is too "vivid" so the reflections from the surfaces ( walls, floor, ceiling) would introduce very emphasis comb-filter effects that are position dependent.

First question: have You ever tried to use larger compression driver (from 4350) instead of smaller compression driver in 4345 ?
Second question: have You ever tried to use DSP assisted EQ and/or DSP driven crossover applied to old 43xx speakers?

Regards
Ivica

Hello Ivica,

Have 4333Bs. Using two I-Tech 5000 HDs in a Bi-Amp. configuration. The biggest improvement in these old JBLs is using a one millisecond delay to the woofers. Cleans up the mid range in a pretty spectacular way. Also using a number of PECs for EQ in the base and upper horn/ring radiator section. In my opinion this configuration produces quite an improvement with these guys. I still cannot believe the definition in the mid range with these old horns. I've owned a number of systems in the past, including B&W 802s and Acustat electrostatics. I will take these old 4333s over them any day.

Regards,

John

[ISAVE]

Hello everybody,

Thank you all for the valuable information, that you added to my knowledge.
Based on the experience that some of you has with these speakers that are out of the book ( I mean not Crown i-tech), I can understand that 1200 watts obsticle is not there.

But 1200w for the D2 is overkill imo... and most likely for the woofer as well for domestic use
A set of smaller Brystons would probably be sufficient. Isn't the recommended Mark Levingson amps 300w?

That's a good point, yes JBL have a alternative setup for them with ML for high end home use. This mean 300 watts should be fine.

Too me, you have the best amp here. Keep it!! There has to be something wrong with your setup.

Why do you set the amp at -25dB? Do you mean Output Level?

I'm sorry I already returned the I-tech 4x3500HD, I couldn't handle the floor noise of this amp or in other word the distortion; it's a great great great touring amp!! but not a studio nor home amp to my opinion.
The -25db I put on the output, because the room can't handle much power, and just a trial to keep the fans working less.
I will get tomorrow a pair of I-tech 5000HD from a local AV company and try them out. Based on papers they have signal-to-noise >112 and THD 0.1% , while the I-tech 4x3500HD has signal-to-noise >108 and THD 0.35%,
So on papers, these should be less floor noise, and I already tested the fan noise, and it's 5 db less on them both compared to the 4x3500HD.
I will update the thread once I did my test.

You do not need 1200 watts per speaker that is a fact 
I have been using a crown DCI N4/300. and it's more than enough for a 3 m. Listening distance 
It all depends the volume you mix with

Thank you Valentin!
This is a helpful answer, now I know that I don't need to be very concerned about getting the sky rocketing 1200 watts!

Now after trying these 5000HD, the next ste is to try out a pair of Bryston 4B SST from a local dealer, I need your help in this:
I don't have a BSS processor, and not willing to buy it until I decide what amps I will end up with.
So the question is: How can I set the Brystons to work properly. I have a digital console Midas M32 that I can rout 4 different outputs and do shelving EQ simulating the crossover role. Also I can set up a delay on the bass outputs, I think it's 0.270 milliseconds?
Any idea if I this could work just for testing purpose?

I spoke today with Bryston Canada, the engineer advised to try a pair or the 4B SST and if the sound had enough power then I keep them the way they are, if not then I can bridge them and get another pair and bridge them. He assured that in case I bridged the amps, I have to make sure that drivers doesn't go below 4 Ohms. Bridging these 4B SST make them 900 or 1000 watts each amp.

Have a wonderful night All

[1audiohack]

[QUOTE]; I will get tomorrow a pair of I-tech 5000HD from a local AV company and try them out. Based on papers they have signal-to-noise >112 and THD 0.1% , while the I-tech 4x3500HD has signal-to-noise >108 and THD 0.35%.[QUOTE]

This is exactly the reason I bought the 5000's. 6dB quieter on the digital side (front end) and lower THD driving such a revealing speaker might just be, well, revealing.

I am keenly interested in how your comparison goes.

All the best,
Barry.

[ivica]

Hello Ivica,

Have 4333Bs. Using two I-Tech 5000 HDs in a Bi-Amp. configuration. The biggest improvement in these old JBLs is using a one millisecond delay to the woofers. Cleans up the mid range in a pretty spectacular way. Also using a number of PECs for EQ in the base and upper horn/ring radiator section. In my opinion this configuration produces quite an improvement with these guys. I still cannot believe the definition in the mid range with these old horns. I've owned a number of systems in the past, including B&W 802s and Acustat electrostatics. I will take these old 4333s over them any day.

Regards,

John

Hi John,
Using time compensation between bass and VHF in order to compensate 12+ inch 2312 horn length is something expectable, even steeper network rasponse (say 24 dB/oct LR round 800Hz) would be wellcome too, I suppose.
In 3amp solution comb filter effect round 9kHz can be reduced using proper time delay of the UHF driver abd 24dB LR network too.
Other EQ I would not expect to be needed (with 2308 lenses installed).
As I have experienced I would prefer 244x&2311&2308 instead of 242x&2312&2308.
Regards
Ivica

[srm51555]

Hi Isave

You do not need 1200 watts per speaker that is a fact
I have been using a crown DCI N4/300.

Hi Valentin,

I also have the dci 4/300n running my diy M2's and was wondering your thoughts between it and the itech series amp.

Thanks,
Scott

[ISAVE]

Hello Barry,

I am keenly interested in how your comparison goes

I had a chance today to get a pair of 5000HD and connect them. I only had less than 30 minutes of listening time.
From this short session it's clear that these amps are noticeably less noise than the 4x3500HD
Also, the fan noise is much less noise on the pair of 5000

I still need to do some serious listening session tomorrow to get clear results.

Now I think I will be able to get 2 Bryston 4b sst demo units to give them a try; I'll try to get them tomorrow.
But I need a configuring of the crossover using a digital mix board. I know it's not gonna be perfect like the preset from BSS or Crown, but at least it should do the basic job of the crossover .

Please anybody can help me with these configuration?

Thanks

[pos]

But I need a configuring of the crossover using a digital mix board. I know it's not gonna be perfect like the preset from BSS or Crown, but at least it should do the basic job of the crossover .

Please anybody can help me with these configuration?

There is not reason for it not to be perfect, as long as you have enough EQ points and flexibility at hand.
Look in my signature for the google doc documenting the EQ settings implemented in the original Crown preset, and ways of adapting them to other DSP devices.

[JBLAddict]

It is designed as a very high quality tool for the recording industry. Some people have repurposed it for home use to great effect, the Harman Luxury division included.

That has been one of the design goals at JBL for quite some time, get rid of the "horn sound" while retaining the power and dynamics. As G.T. stated a few years back "We got rid of that a long time ago...".

Each component (including the enclosure) of the M2 sports the latest and greatest R&D Harman can muster. The active filters with DSP is icing on the cake. Quite frankly, the system potential is just too damn good to eff up with a bunch of passive filter components. (I feel the same way with respect to the higher end JBL Consumer products too but I can certainly empathize with the ease of use of passive filters for them, not to mention the fact that they are Consumer products as opposed to Pro products).

I talked with Kevin at one of the trade shows a couple years ago right next to the M2. I have yet to meet anyone who has said "meh" or "whatevski" to the M2...

I went to "THE Show Newport" two days ago and spent some time talking to Kevin and the other guys in the three Harman rooms (one with K2 playing at an inaudible whisper, and two Revel rooms that that were clearly their focus). I Asked about the future of JBL Synthesis and a few other things. He (and the other guys) elaborated on a few details that from a brand name perspective were very encouraging, quite the opposite of the speculation I've read here--we shall see How this manifests in terms of new products and their relationship to the heritage. To the scope of this thread, it took him no time flat to state his opinion on "what's wrong with all horns", but the admiration he has for what was accomplished with the M2 as a result of Harmans talent and infrastructure--was very complimentary of Floyd Toole in that respect. Anyway don't want to reprint the full conversation but it appears high end is far from dead and Kevin does hate horns indeed :-)

[ISAVE]

Hello all,
I would like to start with special thank you to POS for his help.

There is not reason for it not to be perfect, as long as you have enough EQ points and flexibility at hand.

Actually I had a chance to get "as loaner" a BSS soundweb blu processor unit and 2 Bryston 4B SST2 power amps:
These amps are 300 watts per channel, they sounded very good, and filled the M2 with good amount of muscular power, no fan noise which give thumbs up to Bryston, very smooth mids and highs.
The only place where I found them not enough is I felt they are not controlling the woofers enough, and I felt I needed more power.
I almost hit unity gain at my mixer in a small-mid size room, and felt they need some more energy boost. I wished I had more output power at a specific audio track.

Here were Crowns I-TECH showed off there muscles.
The low frequencies that Brystons gave is not bad at all, nor missing anything; it's wonderful and smooth but they are just not moving the woofer enough or as powerful as the Crowns did.

On the other hand I liked the sound of the D2 drivers with Bryston a bit over the Crowns, more smooth and a bit less THD, while I heard the same details from both.
Brystons on paper are much less THD and noise overall than I-TECH-5000HD, but when used with the M2 the difference appeared less to my ears.

The thing is I didn't had them at the same time to do A/B, and only had the Bryston for one short day.
Also I tried to bridge the the Brystons to power one M2 each driver from a full 4B SST2 which is about 900-1000 watts, I couldn't tell much difference as I only had one M2 up. But I felt the woofer moved better.

Doing that will require 4 Brystons amps for a pair of the M2 which will significantly increase the system cost a lot.


FYI
My media source is Fiio X3 though Soundcraft EFX-8 mixer
My listing materials are "Modern Cool" and "Night Club" albums to "Patricia Barber" ripped mp3 @256Kbps


I would like to apologize for the long explanation, but I felt that some of you would like to hear how the test went.

At this point, I don't know how to proceed.

Regards

[srm51555]

I would like to apologize for the long explanation, but I felt that some of you would like to hear how the test went.

At this point, I don't know how to proceed.

Thanks for the update. I was wondering what the results were. It may seem like you want to try something like Johan is doing with the Crown on the bottom and something else on the top. This is the way I'm leaning towards if I stay active.

Is there any place in the Chicago area where one can demo a pair of M2's. I'm only about 90 minutes north and would like to hear a production unit for comparison to my DIY versions.

Thanks,
Scott

[ISAVE]

Hi Scott,

 It may seem like you want to try something like Johan is doing with the Crown on the bottom and something else on the top. This is the way I'm leaning towards if I stay active  

I thought of doing actually, and this would be a nice setup if these speakers will be used as a high end home HiFi speakers.
While for a monitoring speakers, I'm kind of afraid of doing this, because there will some different in the signal curve between different amps types.
I believe this can be corrected through a BSS DSP, but I this need high level of audio engineering that I'm afraid I can't do it perfectly.

My use for them is for both, as a High End home HiFi, and a reference monitoring speakers for my recording mixer.

Is there any place in the Chicago area where one can demo a pair of M2's. I'm only about 90 minutes north and would like to hear a production unit for comparison to my DIY versions.  

I couldn't find a place where they demo these speakers, as they are not meant for home use originally and studios that consider having them, they have special arrangements for testing.
The other option is you are welcome to come over to my home and listen to them, once I had them powered.

Regards