M2 residential amplifier choices???

[Champster]

I'm very familiar with actively amplified systems but am disappointed that there isn't a high power amplifier choice for the M2 that would serve the 1200W minimum requirement without fans. I've talked to 3 different JBL dealers and the (different) recommended amps are the CDi 4x1200, the DCi 4x1250 or the super powerful iTech 4x3500. There is a Levinson option through Synthesis but those are far lower power (531H @ 300W) and if you study the M2 the real holly grail of this speaker is to deliver tremendous (dare I say, life-like) dynamic range so that at a normal 85dB average listening level, you can still get 20-30dB of undistorted headroom for those peaks.

I'm hoping someone on the Forum has come up with a solution to this problem and is willing to share the idea.

TIA

[Fitero]

I took a different route after trying several amplifiers with them. I even powered them briefly with a 35WPC tube amp as a test.

I had Bob at AB Systems Amplifiers put together a 4 channel, 300WPC amp for me. No fan noise, and has more than enough grunt for domestic use. If you want, he has a 525WPC model as well. All power ratings are at 8 ohms all channels driven continuous sine wave.

https://www.abamps.net/

[Mitchco]

Another member's M2 system using Benchmark AHB2 amps: https://www.audiosciencereview.com/forum/index.php?threads/jbl-m2-audiolense-digital-crossovers-w-subs.2369/

While not M2's the JBL 4722's I use have similar woofer tech and I drive them with Crown XLS 1502 DriveCore 2 Series amps: https://www.crownaudio.com/en/products/xls-1502

There are a few models to choose from and can be bridged mono. If the fan has ever turned on, I can't hear it, even right up close to the amp. I am impressed with the sound quality, headroom and damping factor of these amps. The XLS 1502 puts out 575W into the 4 ohm load with the double 15" woofers per side. At extreme level's I can get the limiter to flash on drum transients, but adding another 1502 in bridged mode would be 1550W per channel.

I can't speak to the high frequency sound quality of the XLS amps, as I run the JBL 4722's biamp (triamp with subs (https://www.computeraudiophile.com/ca/ca-academy/%C2%A0integrating-subwoofers-with-stereo-mains-using-audiolense-r712/)) and the amps are used to drive the bass cabs. Really impressed with the tight bass and impact. I upgraded the CD to JBL 2453H-SL and driving those with Nelson Pass flea watt ACA amps (https://diyaudiostore.com/products/amp-camp-amp-kit?variant=7072933085218) directly connected to the CD's with a protection cap and no padding. Dead silent, no hiss, lovely SQ.

It would seem to me that a couple of bridged XLS 2502 with 1550W at 8 ohms per channel would give you plenty of headroom driving the M2 woofers. I have never heard the fan and if you check out Amazon reviews, the majority of folks are impressed with the SQ, especially at this price point :)

Good luck!

[baldrick]

If you want OEM path you will either need BSS DSP or Crown DCIN or iTech HD. With BSS DSP you could more or less buy any decent poweramps. The easy way is to buy Crown, I have DCI4/600N. Difference between 4/1250 and 4/600 is just power, you will never need more than 600, DCI4/300N would probably also work excellent.

Otherwise you could of course use other DSP solution than Crown/BSS, but I would stick to BSS and My all in all advice would be Crown DCI4/600N

[Champster]

If you want OEM path you will either need BSS DSP or Crown DCIN or iTech HD. With BSS DSP you could more or less buy any decent poweramps. The easy way is to buy Crown, I have DCI4/600N. Difference between 4/1250 and 4/600 is just power, you will never need more than 600, DCI4/300N would probably also work excellent.

Otherwise you could of course use other DSP solution than Crown/BSS, but I would stick to BSS and My all in all advice would be Crown DCI4/600N

Thank you, Baldrick. I'm assuming this is your home system, do you ever hear the fans? Are the amps in the same room as the speakers?

[Champster]

Another member's M2 system using Benchmark AHB2 amps: https://www.audiosciencereview.com/forum/index.php?threads/jbl-m2-audiolense-digital-crossovers-w-subs.2369/

While not M2's the JBL 4722's I use have similar woofer tech and I drive them with Crown XLS 1502 DriveCore 2 Series amps: https://www.crownaudio.com/en/products/xls-1502

There are a few models to choose from and can be bridged mono. If the fan has ever turned on, I can't hear it, even right up close to the amp. I am impressed with the sound quality, headroom and damping factor of these amps. The XLS 1502 puts out 575W into the 4 ohm load with the double 15" woofers per side. At extreme level's I can get the limiter to flash on drum transients, but adding another 1502 in bridged mode would be 1550W per channel.

I can't speak to the high frequency sound quality of the XLS amps, as I run the JBL 4722's biamp (triamp with subs (https://www.computeraudiophile.com/ca/ca-academy/%C2%A0integrating-subwoofers-with-stereo-mains-using-audiolense-r712/)) and the amps are used to drive the bass cabs. Really impressed with the tight bass and impact. I upgraded the CD to JBL 2453H-SL and driving those with Nelson Pass flea watt ACA amps (https://diyaudiostore.com/products/amp-camp-amp-kit?variant=7072933085218) directly connected to the CD's with a protection cap and no padding. Dead silent, no hiss, lovely SQ.

It would seem to me that a couple of bridged XLS 2502 with 1550W at 8 ohms per channel would give you plenty of headroom driving the M2 woofers. I have never heard the fan and if you check out Amazon reviews, the majority of folks are impressed with the SQ, especially at this price point :)

Good luck!

Thank you, Mitchco. I'll check, but do these have the built in DSP to load the software?

[ngccglp]

I’m really keen on the iTech 4x3500. Anybody has any experience with them? Especially the fan noise.

[Ian Mackenzie]

I'm very familiar with actively amplified systems but am disappointed that there isn't a high power amplifier choice for the M2 that would serve the 1200W minimum requirement without fans. I've talked to 3 different JBL dealers and the (different) recommended amps are the CDi 4x1200, the DCi 4x1250 or the super powerful iTech 4x3500. There is a Levinson option through Synthesis but those are far lower power (531H @ 300W) and if you study the M2 the real holly grail of this speaker is to deliver tremendous (dare I say, life-like) dynamic range so that at a normal 85dB average listening level, you can still get 20-30dB of undistorted headroom for those peaks.

I'm hoping someone on the Forum has come up with a solution to this problem and is willing to share the idea.

TIA


A few things come to mind.

If you are in a domestic situation can you ever imagine running the M2'S at levels requiring 1200W headroom?
The 1200 watt amp rating is more a safety measure so as not to clip the amp (square wave) which would probably damage the drivers.

So if you can live wth 6 db less headroom it opens up some amp options without fans that do DSP in the Crown range.

In any case fan noise of any kind an going to cloud the resolution of the system....

I sticking with the crown amps with the embedded dsp for the M2 is easier on setting up the system.
The alternative is the BSS DSP and you can buy any descent power amps but the BSS DSP is reported to also produce fan noise.
So there is no advantage going that route.

Therefore it might be worth looking at the feasibility of amps in a separate room.

[baldrick]

Thank you, Baldrick. I'm assuming this is your home system, do you ever hear the fans? Are the amps in the same room as the speakers?

DCI amps have fans with noise, not the worst fan noise, but absoluttely noticalbe, but iTech is louder. I know a few have sucsefully replaced DCI fans with much more silent, but it's not as easy as with i.e. CTS amps since there are sensors with the DCI. Most BSS DSPs do also have fans, only the smallest one 50 (?) are fanless.

[martin_wu99]

I think Mcintosh/Mark/Bryston/etc. are more suitable for M2 in home HiFi system,300W/PC is enough,they will drive M2 more smooth and musical,those pro gears such as Crown are too harsh in the home system,of course you need a BSS to load M2's software.

[Titanium Dome]

Taking a cue from Greg Timbers’ set up, you could put the noisy stuff in an adjacent room if your place has an adjacent, available space.

in his case, there’s a bedroom closet on the other side of the wall in his living room, so many of the noisy, heat producing, spaghetti-wiring-connection-forming gear is in the bedroom closet, and his front end sources are the only things in the main room. The sliding closet doors are removed, so there’s plenty of air for the gear to breathe.

Luckily, I have a similar closet next to the room I’m using, and the JBL Synthesis SDA-4600 amps go in there. The SDAs accept the M2 files, and a pair of them handle three M2s with channels to spare. A standard outlet sized opening between the two rooms is all that’s needed.

[Wayner]

Back when Harman Professional had the staff at BSS, JBL and Crown, they were able to fully engineer a system like the M2. It's complicated hardware, software and acoustics. Even across inner-company division lines, those guys were able to sort through all the compromises required to make the system fulfill a demanding product definition. It started with the I-tech because that was the amp that had the necessary DSP and amplifier horsepower. Of course it's way over-powered, but you can dial the amps back in firmware. Of course the fans sound like turboprops, but users can isolate that noise. The DCi came along as a state of the art permanent installation amp. And the CDi Drivecore followed as a more cost-effective install solution. With both of these new amps it was necessary develop and validate new files used for all the speaker tunings. They all went through evaluation / optimization at JBL. So you're unlikely to hear any difference among these three amps driving the M2. Further, JBL used BSS sound processors and Mark Levinson amps to go through the Synthesis channel. Same development process. The JBL Synthesis SDA-4600 is a rebadged DCi 4x600.

It's not just a matter of having DSP in the amplifier. It needs sufficient processing power and it needs the correct tuning files for the operating system in the amplifier. That exists only in the I-Tech, DCi and CDi.

The I-Tech is a touring amplifier. It is the embodiment of robustness. Thermal management is critical and the sound level coming from the fan is of zero concern. Well that's what I think but marketing types kept saying the fan is too loud. At any rate the amplifier is incredibly capable and is able to work well in a studio setting if you isolate the fan noise. Anyone who says a Crown amplifier is harsh is on the other side of a great divide from me - and all the early adopters of the M2 who hailed it as a revolutionary system. So for the guy asking about I-Tech, you will love the amplifier until the end of time. But the fan is super loud.

If you have a 4x300 watt amplifier, it's going to need a fan to keep components cool enough to last a long time. Yes, yes, of course you can design an amplifier with that power that doesn't have a fan. But there are plenty of other compromises made to make that possible. At 4x600 a fan is pretty much inevitable.

Maybe it bears repeating that the M2 is a system that includes the amplifier. I can even imagine that the JBL guys would have preferred an amplifier integrated into the cabinet if not for weight and heat. That and the development cost. And just like we talk about driver choice, with better drivers being available in the JBL catalog, you might find better amplifiers. But I'm certainly not going to swap out the drivers in my M2. (However, I DID swap out the drivers and crossover in a pair of Klipschorns as a reference) In the same light, I have a BSS Blu-806 and can therefore connect any amp I want. But I'm super happy with a CDi 4x1200. My opinion is the CDi fan is similar to white noise and not intrusive as an ambient sound. I hear it between songs but not during quiet moments in the music. I haven't yet done anything to absorb the fan noise or install a quieter fan. Maybe I will but to my way of thinking those changes are totally benign to the M2 system compared to putting in fan-less third party DSP and amplifier components.

And let me be clear. I don't have anything bad to say about using 3rd party DSP and amplifiers. I just don't have the capability to implement that properly.

So my two cents is the CDi 4x1200 is very good amplifier in the M2 system. That's no different than the dealer's advice, so I haven't offered a new recommendation. But I hope my comments have added a little insight to our community.

[Champster]

Awesome suggestions! Thank you all for your 2¢.

I had the opportunity to talk to a senior engineer for ATI and he confirmed that Ian offered in that these speakers need large amps, not because they are inefficient but because they are capable of such impressive amounts of dynamic range and that you don't want your amp clipping during these peaks. It is for this reason that he helped me calculate that I need a minimum of 450W to reach 110dB at my listening position. Having this or more will provide for very satisfying listening in the 80-85dB range.

So, I'd like to stay away from the fans which drives me to the BLU-50 but then it is pretty hard to find an amp without fans that delivers >450W. So I think I'll just get an amp with fans. I'm thinking the DCi 4x600 or preferably the SDA-4600.

Again, I don't have another room to put it in but I do have an unused fireplace or I was wondering if there are cabinets made that would enclose the amp without letting it get too hot. I'll have to do a Google search to find that out.

Thanks for all of your input. It is super helpful!

[Ian Mackenzie]

This is a great discussion on a solution.

The other thing to consider is in your domestic scenario during listening what level is going to be your cruising altitude?

For example in party mode (110db average 2 metres) I doubt you will detect fans. After about an hour of that my ears tend to compress.

RMS power is what generates heat so if your pro sales engineer can calculated when the power amp fans will come on it might not be as big an issue as might seem.

Depending on how the amp cooling management is programmed you might escape fan noise at say 100 db average which at 2 metres is loud.

But if the amp fans are on at 90 db average that might not be satisfactory unless they are variable speed fans.

I think Don who has M 2's would be one person to discuss experiences with Crown amps

For my own part I need dead silence at normal listening levels (90 db average) so I can enjoy the resolving power of the system.That means zero mechanic noise which is not as easy as you might think.

The trade off in my scenario is heat with the Pass Labs X250.5 which is 300 watts via massive heat sinks but I can live with that.

[Champster]

This is a great discussion on a solution.

The other thing to consider is in your domestic scenario during listening what level is going to be your cruising altitude?

For example in party mode (110db average 2 metres) I doubt you will detect fans. After about an hour of that my ears tend to compress.

RMS power is what generates heat so if your pro sales engineer can calculated when the power amp fans will come on it might not be as big an issue as might seem.

Depending on how the amp cooling management is programmed you might escape fan noise at say 100 db average which at 2 metres is loud.

But if the amp fans are on at 90 db average that might not be satisfactory unless they are variable speed fans.

I think Don who has M2's would be one person to discuss experiences with Crown amps

For my own part I need dead silence at normal listening levels (90 db average) so I can enjoy the resolving power of the system.That means zero mechanic noise which is not as easy as you might think.

The trade off in my scenario is heat with the Pass Labs X250.5 which is 300 watts via massive heat sinks but I can live with that.


Thank you, Ian, again for your great points. I realized I wasn't very clear about my listening habits. I typically listen at about 85db and rarely reach anything close to an average listening level of 100dB. I hate distracting noises around the house when I'm listening and in fact usually wait until everyone else is gone to sit down and listen.

I am not familiar with Don. How could I get in touch with him? I would really appreciate hearing from wise ones that have traveled down this path before me...

[Fitero]

I used an SDA-4600 amp for awhile with my M2's, but didn't care for the elevated hiss I heard in my system. That in conjunction with the fan noise made me choose the AB class amp route.

I have eliminated the SDEC-3500 fan noise by placing a 200mm pancake fan on top of it. I can't hear it at my listening position which is 4 feet from the unit.

One option for you might be to rent any of the available Pro-Audio amplifiers from your local retailer. It is a very cheap option. It will give you an idea of how much power you require and how much fan noise you are willing to accept.

[Ian Mackenzie]

Don McRitchie is the site webmaster.

Send Don an email or Pm.

[Ian Mackenzie]

Here is an idea that you may wish to consider.

Do you remember the noise matrix printers made?
Supplies sold them with Perspex sound barrier enclosures that had a hinged flap to access the print out.

Using a similar approach you could attempt to blimp the amp fan noise.

What comes to mind is either thick Perspex or 1 inch mdf enclosure with 6 inches clearance around all dimensions of the amps. All internal surfaces should be lined with sound barrier house insulation.

At the rear you have 2 six inch holes placed at either end. Install a 6 inch Papst low noise fan in each hole so the air flows in and out of the enclosure

Connect a 1 or 2 metre air con insulated duct pipe to each hole. The pipe will tend to act as a venturi increasing air flow while absorbing noise.

The cables can be fed through a cable gland and sealed with duct tape.

There is no guarantee this would be completely effective but if it did it would solve a headache among domestic M2 users. It might take some experimentation to come up with an effective design.

[1audiohack]

... I typically listen at about 85db and rarely reach anything close to an average listening level of 100dB. I hate distracting noises around the house when I'm listening and in fact usually wait until everyone else is gone to sit down and listen...

Then they (Crown I-TECH HD amp fans) will drive you crazy. While it’s true that the fans are variable speed, they always run and they have a habbit of randomly going full speed, only for a second and seemingly just for the fun of it.

When mine finally make it into my primary listening space, they will be in a vented cabinet to silence them.

On the flip side of this, I was told by an engineer at JBL that the I-TECH 5000HD was selected as the prime amplifier system for the M2 as the all in one design amp-DSP because it allowed a 6dB lower noise floor than any other option available to them. At the time I bought my 5000HD’s my careful digging in the Crown literature I found the 5000’s had a lower noise floor/higher dynamic range than the four channel 3500HD. That was years ago and without looking I don’t remember exactly where I found that.

The old ear to the tweeter test has never heard a quieter 1200+ Watt per channel amp. :) They are dynamic as hell too.

So that may be more than you asked but there is my solid reasoning for putting up they them.

Barry.

[Champster]

Thank you to everyone that has contributed to this thread. I’ve placed my order and, thanks to this Forum’s members, I feel confident that I will in one way or another be able to tame the fan noise. I’ve settled on the DCi 4x1250 amp to power the M2s.

They are paid for and should be delivered early next week.... Christmas in November!!!

[baldrick]

Hopefully you meant DCIN and not DCI without DSP :)

i have 2 of them and will be useing them for my subs.

[Champster]

Hopefully you meant DCIN and not DCI without DSP :)

i have 2 of them and will be useing them for my subs.

Good catch. Yes the Network (n) version. Thanks for the clarification.

[Jonas_h]

1audiohack: Apart from the fan noise are there other drawbacks with the itechs compared to for example the Levinson's? I have not done intensive A/B testing between amps but I often read people mentioning lack of 'air', resolution and smoothness (I hate hifi terms:)) on for example the itechs.

But I really like the idea of getting the amps which M2s are designed for and the Class I tech is also really interesting.

[sguttag]

I auditioned a few amplifiers...the winner for me, in my room was the QSC DCA 2422. While not the 1200-watt power amp you are seeing, in my 16-foot deep room, it showed that is was more than sufficient to get the room up to over 105dBc from my listening position with any speaker or 108dBc in stereo. To use a larger amplifier, in my opinion was just going to be a waste of money. The DCA line is AB and H class (the 2422 is Class-H), which may not be high-brow enough for some but I think they sound pretty good. I auditioned them on the M2s.

The DCAs to have fans but they only spin on turn-on and when they are required to remove heat. Where I'm placing them, they won't be heard, even if the fans do turn on.

[1audiohack]

1audiohack:...Apart from the fan noise are there other drawbacks with the itechs compared to for example the Levinson's?...

I wish I could say that I have been able to audition the Levenson's but I have not.

I don't have any "top tier" audiophile amps. I compared the I-TECH's to several other amps on my 4365's and while nothing I compared sounded decidedly better, they are just a tick different as most amps are. I thought the HF was about as good as my normal amps that are flat to over 40kHz and extend to 100k.

My SAE2400L, when it's working, has the most high end sparkle of any amp that I have, but I don't know if it is really flat. It has a bad habit of dropping burning embers out of the bottom of it on power down. :(

Barry.

[Champster]

82706

Now to figure out how to load the M2 file on the 4x1250......

[Jonas_h]

82706

Now to figure out how to load the M2 file on the 4x1250......
Did you figure it out? :)

[Champster]

Did you figure it out? :)

Not yet. I haven’t had time to sit down quietly and do it but Baldrick sent me what appears to be just the ticket for getting it loaded and playing tunes...

[srm51555]

Nice!!!

[Champster]

Well the loading of the files was way easier than I expected especially with this help sheet and file provided by Baldrick. Here is the link to that thread.
http://www.audioheritage.org/vbulletin/showthread.php?41140-Loading-JBL-M2-DSP-file-on-Crown-DCi-4x1250

The only steps not covered in the help sheet is to connect the network capable amp to your router via ethernet cable and turn it on. To protect from anything going wrong, I didn't connect amp to any input or output cables to my system. Before doing that, I wanted to make sure the files were loaded properly in the DSP. You'll need a PC to run the AudioArchitect software and it will wirelessly connect to the amp to install the files. Also, in this DSP you install files for each amp as opposed to the miniDSP style of installing one file for the entire audio spectrum. The miniDSP system seems more sophisticated in this respect, but that is a minor point.

Ok, back to the fan noise. That thing is way too loud for a home environment!!!! I'll have to figure something out there. Although the fan is in the back, the fan noise comes out the front of the amp through the openings.

Paul

[martin_wu99]

No need for these ugly pro beasts at all, and no need to bear their fan noise:crying:

[Champster]

No need for these ugly pro beasts at all, and no need to bear their fan noise:crying:

No need other than that you cannot achieve the peak sound pressure levels of 110dB at the listening seat in my room without >450wpc… If you want to really tap into the potential dynamic range of the M2s, your amp need the ability to hit these peaks and for that, Sir, you need pro amp power levels. Other than that, you're right.

[Ian Mackenzie]

Does the fan noise come from the front or the rear?

How loud is it?

Here is another idea.

I assume you are familiar with noise canceling headphones.
The noise from the fan could conceivably be cancelled out or significantly reduced by recording or amplifying the fan noise at the source and then playing the noise through a small loudspeaker at the source with the phase reversed at the driver. You could try this with a small microphone connected to an amplifier. You may need to experiment with the location of the mic and loudspeaker for best result.

[martin_wu99]

No need other than that you cannot achieve the peak sound pressure levels of 110dB at the listening seat in my room without >450wpc… If you want to really tap into the potential dynamic range of the M2s, your amp need the ability to hit these peaks and for that, Sir, you need pro amp power levels. Other than that, you're right.
Who will play M2 at 110dB sound pressure level in his living room?:eek::crying:

[Ian Mackenzie]

Most of us

[martin_wu99]

Most of us
Unbelieveable:blink:

[pos]

No need other than that you cannot achieve the peak sound pressure levels of 110dB at the listening seat in my room without >450wpc… If you want to really tap into the potential dynamic range of the M2s, your amp need the ability to hit these peaks and for that, Sir, you need pro amp power levels. Other than that, you're right.
emphasis mine

[Ian Mackenzie]

Unbelieveable:blink:

Hi Martin,

While it is true the first watt is the most important the real headroom for un compressed (and un clipped) dynamics cannot be underestimated.

For example I currently run 2 x 800 watts RMS for both woofers and 2 x 250 watts RMS on the mids and highs of my 4345 system.

Allowing for a minimum 6db of headroom these amplifier ratings are realistic.
Modern software using the DSD platform for transfers from master tapes pushes the envelop for more headroom even further.

The presentation has a realism that is awe-inspiring. Noting even comes lose.

Putting it in perspective the average consumer hifi loudspeaker has about 90 db sensitivity @ 1 metre for 1 watt. People who have not have moved over to the larger monitors might still think in the terms of what domestic loudspeakers sound like.

Using a single 2 x 100 watt amplifier which might be considered the norm (for the Hifi buff) with a domestic loudspeaker is not going to create anything like the same presentation. It just won't.

Systems with adequate headroom and low power compression don't actually sound loud or fatiguing.

I hope that makes sense.

Ian

[Champster]

Mostly from the front even though the fan is in the rear of the amp.

It adds about 3-5dB to the noise floor of my room.

I've figured out a solution. There is a wall in my living room with a large void. I'm going to build an enclosed cabinet in to hide all of my audio gear.

Thanks
Paul



Does the fan noise come from the front or the rear?

How loud is it?

Here is another idea.

I assume you are familiar with noise canceling headphones.
The noise from the fan could conceivably be cancelled out or significantly reduced by recording or amplifying the fan noise at the source and then playing the noise through a small loudspeaker at the source with the phase reversed at the driver. You could try this with a small microphone connected to an amplifier. You may need to experiment with the location of the mic and loudspeaker for best result.

[Champster]

Mr Wu,
I 100% agree with Mr Mackenzie's answer to your question. I am so impressed with the combination of the Crown 4x1250n amp and the M2s. And just so you know, I typically listen at about 85dB, so not very loud. I've had, and listened to, a lot of very high end speakers and none have come close to the life-like presentation (dynamics) and clarity of the JBL M2 system. And this is even true at low SPLs. Horns, drums and vocals are ridiculously intoxicating and I can say I've never heard sounds presented like this ever before. For reference, this comparison includes both a WAMM and an Infinity IRS.
Paul




Hi Martin,

While it is true the first watt is the most important the real headroom for un compressed (and un clipped) dynamics cannot be underestimated.

For example I currently run 2 x 800 watts RMS for both woofers and 2 x 250 watts RMS on the mids and highs of my 4345 system.

Allowing for a minimum 6db of headroom these amplifier ratings are realistic.
Modern software using the DSD platform for transfers from master tapes pushes the envelop for more headroom even further.

The presentation has a realism that is awe-inspiring. Noting even comes lose.

Putting it in perspective the average consumer hifi loudspeaker has about 90 db sensitivity @ 1 metre for 1 watt. People who have not have moved over to the larger monitors might still think in the terms of what domestic loudspeakers sound like.

Using a single 2 x 100 watt amplifier which might be considered the norm (for the Hifi buff) with a domestic loudspeaker is not going to create anything like the same presentation. It just won't.

Systems with adequate headroom and low power compression don't actually sound loud or fatiguing.

I hope that makes sense.

Ian

[martin_wu99]

Mr Wu,
I 100% agree with Mr Mackenzie's answer to your question. I am so impressed with the combination of the Crown 4x1250n amp and the M2s. And just so you know, I typically listen at about 85dB, so not very loud. I've had, and listened to, a lot of very high end speakers and none have come close to the life-like presentation (dynamics) and clarity of the JBL M2 system. And this is even true at low SPLs. Horns, drums and vocals are ridiculously intoxicating and I can say I've never heard sounds presented like this ever before. For reference, this comparison includes both a WAMM and an Infinity IRS.
Paul
Dear Paul,

I do believe your wonderful feeling of M2 combining with Crown pro.but i don't believe Crown pro can be even better than those HiFi gears such as Mark,Mcintosh,Pass, etc at low SPLs:eek::dont-know:

Martin

[hlaari]

82706

Now to figure out how to load the M2 file on the 4x1250......


have you compare the Linkwitz Lab speakers to the M2?





Ari

[1audiohack]

Dear Paul,

I do believe your wonderful feeling of M2 combining with Crown pro.but i don't believe Crown pro can be even better than those HiFi gears such as Mark,Mcintosh,Pass, etc at low SPLs:eek::dont-know:

Martin

Hello Martin;

I am not picking on you, I am only using your statement as an example of a sentiment that has always made me wonder why they could not be.

If the noise floor is sufficiently low and the output is truly linear to the input, where are the details or definition lost?

I won’t argue that all amps sound the same as they clearly don’t but I don’t understand why a top quality big pro amp could not compete with any other top quality amp designed for domestic use.

This a question I don’t expect to find a solid answer to. Maybe some day I will get to compare some top shelf audiophile amps to some of my top shelf pro amps.

All the best,
Barry.

[johnlcnm]

I have to agree with Champster on the use of Crown Pro amps. I'm using two Crown ITEC5000HD's in a biamped system. Amps were used when I acquired them. Both the balanced analog inputs and AES digital inputs are connected. Fan noise IS an issue. But the AES input is the cats meow. The sound depth and detail are better then anything I have ever tried in my space, and I have had and still own a number of "analog" amps, plus a two decent D/A converters.

[ngccglp]

Most of us

Agree totally. Why else would we buy 15” woofers and 4” Drivers and horn?

[martin_wu99]

Mostly from the front even though the fan is in the rear of the amp.

It adds about 3-5dB to the noise floor of my room.

I've figured out a solution. There is a wall in my living room with a large void. I'm going to build an enclosed cabinet in to hide all of my audio gear.

Thanks
Paul
Everyone has his own taste,i hope i will not disturb your interesting,just enjoy your M2 and Crown pro.:)

[DES-1]

I've figured out a solution. There is a wall in my living room with a large void. I'm going to build an enclosed cabinet in to hide all of my audio gear.


I think this is a great idea and depending on design it will also serve to reduce visual clutter. It seems its always been part of the audio culture to prominently display all the gadgets, plus components had to be close to the input devices and fairly close to the speakers. And, after all, most are beautifully designed and serve as eye candy so they demand to be displayed.

My challenge is space for the various components and I don't want my family room looking like an electronics bay. If by some miracle my wife will allow my clone speakers into the family room, I'll probably locate all the electronics in the basement and eliminate all input sources that can't be remotely controlled. I was originally going with vintage amplifiers, receiver and turntable for a classic look, but with them out of sight I'll switch to something more contemporary, maybe will end up with Crowns myself.