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post #4171 of 4705 Old 11-22-2018, 11:03 AM
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Hello all,

I do not know if this has been answered already as this is a huge thread, but can the JBL M2s be connected to an amplifier different than the Crown or the Mark Levinson one? The Crown has 1200 Watts per channel whereas the ML 535H 200W. I have a Parasound HCA-2205a which is 220W for each of the 5 channels and I was wondering if that can work fine, at least until I upgrade my amp?

I am a bit confused whether the Crown is the best option even on top of the ML one as the 15 inch woofer should require ample power? Can an iNuke work just fine instead?

AVR: Marantz SR7011 (11.2 Atmos/DTS-X/Auro3D), Amps: Parasound HCA-2205a, Rotel rkb-8100, Front L/R: Tannoy DC10Ti, Center: Tannoy D750, Surrounds: Kef 3001, B&W 601S3
Heights: Focal Domes, B&W M1, Subwoofers: Tannoy TS2.10, Genelec HTS4
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post #4172 of 4705 Old 11-23-2018, 06:33 AM
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Hello all,

I do not know if this has been answered already as this is a huge thread, but can the JBL M2s be connected to an amplifier different than the Crown or the Mark Levinson one? The Crown has 1200 Watts per channel whereas the ML 535H 200W. I have a Parasound HCA-2205a which is 220W for each of the 5 channels and I was wondering if that can work fine, at least until I upgrade my amp?
I am a bit confused whether the Crown is the best option even on top of the ML one as the 15 inch woofer should require ample power? Can an iNuke work just fine instead?
You can use any amp as long as it has enough power to drive the speakers to the level you want. If you use amps without the processing, you need a BSS Soundweb unit to handle the crossovers and processing.

Be aware that many of the high power amps have noisy fans and you need to locate them so they don't interfere with your listening pleasure.

Last edited by Rex Anderson; 11-23-2018 at 08:04 AM.
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post #4173 of 4705 Old 11-23-2018, 06:39 AM
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Also available in a powered version as the LSR 705P. And, if you want something bigger (8" woofer instead of 5") look at the LSR 708i or LSR 708P.


That’s a good point. For desktop use the powered ones are quieter, and they’re a lot cheaper.

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post #4174 of 4705 Old 11-23-2018, 01:40 PM
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You can use any amp as long as it has enough power to drive the speakers to the level you want. If you use amps without the processing, you need a BSS Soundweb unit to handle the crossovers and processing.

Be aware that many of the high power amps have noisy fans and you need to locate them so they don't interfere with your listening pleasure.
Thank you very much for the answer, I suspected as much. Is that a common practice to wire two different amps for the Woofer and the Tweeter? E.g the Tweeter could be connected to the Parasound and the Woofer to a cheaper Crown, or an inuke with a silent fan mod.

In addition is it also a valid alternative practice for the crossover to be done with a cheaper minidsp 2x4HD instead of the BSS unit, like other case of active biamping? The processing would be done in my case by a Marantz receiver with Audyssey XT32 and Atmos processing further up the chain.

How much of the JBL Synthesis experience and sound quality does one lose that way, if that is a valid question to ask? I read much of it lies in the preset DSPs for the crown and the BSS settings? Does Dirac/Audyssey/Minidsp/Inuke DSPs can close? For me it is a hypothetical scenario replacing my front Tannoy DC10Tis which are very musical and cinematic with the Parasound, with the JBL's hoping for something hopefully even more refined audio-wise and jaw-dropping cinema-wise, without necessarily approaching a lot of SPL in my medium UK-sized room, and with a minimum change to amps.

AVR: Marantz SR7011 (11.2 Atmos/DTS-X/Auro3D), Amps: Parasound HCA-2205a, Rotel rkb-8100, Front L/R: Tannoy DC10Ti, Center: Tannoy D750, Surrounds: Kef 3001, B&W 601S3
Heights: Focal Domes, B&W M1, Subwoofers: Tannoy TS2.10, Genelec HTS4
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post #4175 of 4705 Old 11-23-2018, 02:18 PM
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It is common practice with Pro speakers or they have the amps built inside them for smaller book shelf sized models but they still use an active design. Using an active crossover and using an amp to directly power each driver has acoustic benefits, over passive designs. When you use a passive design the crossover uses some of the amplifier power, it also add distortion. A passive crossover can only cut frequencies. Simply a passive crossover cuts the low frequencies from going to the tweeter and the high frequencies going to the woofer. An active crossover can be a LOT more precise and can boost frequencies if needed. it can also be more precise on the phase of each. When you power a driver directly from an amp distortion goes way down plus the attack of the sound goes up like 10 times quicker than going through the passive crossover. On top of this the DSP can offer better speaker protection so it is not as easy to blow the speakers. The only advantage a passive speaker has is ease of wiring as you only need 1 pair of speaker wires per speaker and cost. This is not to say passive speakers sound bad, they don't. But, if you take the same speaker and made a passive and an active version the active version would outperform the passive version.

In the pro world active speakers are commonplace whether they have the amp, crossover and DSP built in or they use multiple sets of speakers wires to have one for each driver. In the consumer world active speakers are rare, mainly because of cost and ease of wiring as well as audiophile myths of pairing amps to speakers and what happens if the active speaker fails. I know we have active pro speakers in installations that get used 12 hours a day and have been running 20+ years. I don't know if some of the less expensive $100 per speaker have a shorter lifespan but even those I haven't heard of a lot of failures. If you are going to a system as expensive as the M2 then I would recommend using the amps or equipment it is designed to be used with. While I have no doubt that the M2 can outperform the Tannoy DC10Tis in so many ways it doesn't account for what I term the mom's spaghetti rule. Meaning everybody's mom makes the best spaghetti and you are used to the sound your DC10s produce. There is nothing wrong with that if you prefer that sound. I would definitely try to listen to the M2s before purchasing, in your room if possible. I make that recommendation to everyone. While research can tout most people prefer more accurate sound, most is not everyone. I'll be interested to hear your impressions.
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post #4176 of 4705 Old 11-23-2018, 07:25 PM
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Thank you very much for the answer, I suspected as much. Is that a common practice to wire two different amps for the Woofer and the Tweeter? E.g the Tweeter could be connected to the Parasound and the Woofer to a cheaper Crown, or an inuke with a silent fan mod.

In addition is it also a valid alternative practice for the crossover to be done with a cheaper minidsp 2x4HD instead of the BSS unit, like other case of active biamping? The processing would be done in my case by a Marantz receiver with Audyssey XT32 and Atmos processing further up the chain.

How much of the JBL Synthesis experience and sound quality does one lose that way, if that is a valid question to ask? I read much of it lies in the preset DSPs for the crown and the BSS settings? Does Dirac/Audyssey/Minidsp/Inuke DSPs can close? For me it is a hypothetical scenario replacing my front Tannoy DC10Tis which are very musical and cinematic with the Parasound, with the JBL's hoping for something hopefully even more refined audio-wise and jaw-dropping cinema-wise, without necessarily approaching a lot of SPL in my medium UK-sized room, and with a minimum change to amps.
You have to use amps that have exactly the same input sensitivity and gain structure. I.e., what is the gain through the amp. Frankly, I would be hesitant to use different amps with the same gain specs. I would use the same amps for all channels. Follow basic procedures and protocol with known devices designed to work with these products or they will not perform as specified.

If you look at posts from notnyt, he has posted the crossover and processor settings. You can not achieve them with a miniDSP. Trying to do this on a shoestring budget is a fool's errand. The speakers need very specific settings. Your Marantz receiver with Audyssey XT32 and Atmos processing further up the chain is for room correction, not for handling what the speakers need to function properly.

M2's need substantial power and processing to perform their best. The specs are well defined. Your Parasound HCA-2205a would handle woofers and tweeters for two M2's with a channel left over. However, 220W per driver may not be enough power to produce the SPL's you might want. And, you still need the crossover and processor settings. Here is the owner's manual and setup instructions for the M2.


https://www.jblpro.com/ProductAttach...anual_RevA.pdf


In your medium UK-sized room without necessarily approaching a lot of SPL, I think M2's are way more than you need. JBL LSR708P's with subs and bass management would be a good option and much easier to configure.
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post #4177 of 4705 Old 11-24-2018, 06:05 AM
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You have to use amps that have exactly the same input sensitivity and gain structure. I.e., what is the gain through the amp. Frankly, I would be hesitant to use different amps with the same gain specs. I would use the same amps for all channels. Follow basic procedures and protocol with known devices designed to work with these products or they will not perform as specified.

If you look at posts from notnyt, he has posted the crossover and processor settings. You can not achieve them with a miniDSP. Trying to do this on a shoestring budget is a fool's errand. The speakers need very specific settings. Your Marantz receiver with Audyssey XT32 and Atmos processing further up the chain is for room correction, not for handling what the speakers need to function properly.

M2's need substantial power and processing to perform their best. The specs are well defined. Your Parasound HCA-2205a would handle woofers and tweeters for two M2's with a channel left over. However, 220W per driver may not be enough power to produce the SPL's you might want. And, you still need the crossover and processor settings. Here is the owner's manual and setup instructions for the M2.


https://www.jblpro.com/ProductAttach...anual_RevA.pdf


In your medium UK-sized room without necessarily approaching a lot of SPL, I think M2's are way more than you need. JBL LSR708P's with subs and bass management would be a good option and much easier to configure.
Alright thank you very much both for the answers. It seems that there is a consensus that if I buy a JBL M2 it should be the way Harman was intended, with the Crowns and London BSS to have the full experience, otherwise it would be subpar. I was reading some posts in the minidsp website from people that use a miniDSP openDRC as a crossover for JBL M2 or another forum about using Audiolense Digital crossovers, with relatively good results, irrespective of which amplifier is used. However this is always subjective unless there are comparisons anywhere in this thread or others with custom solutions vs the full Harman chain? Am I also correct to say that Harman's ARCOS that is used in the JBL M2 Room Eq. is one step up even from Dirac? In the case of an external pre-pro or receiver higher up the chain for sound processing, is then common practice to bypass the REQ for any JBL M2 speaker, and let the Harman system do its own thing?

At the end of the day if M2s are an overkill for a medium sized room I might as well keep the 10 inch Tannoy, arguably an overkill too, rather than going to an 8 inch driver for the sake of simplicity. Unless even the JBL LSR708P with bass management and subs is also so much better for audio and home cinema?

Thank you in advance.

AVR: Marantz SR7011 (11.2 Atmos/DTS-X/Auro3D), Amps: Parasound HCA-2205a, Rotel rkb-8100, Front L/R: Tannoy DC10Ti, Center: Tannoy D750, Surrounds: Kef 3001, B&W 601S3
Heights: Focal Domes, B&W M1, Subwoofers: Tannoy TS2.10, Genelec HTS4
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post #4178 of 4705 Old 11-24-2018, 06:33 AM
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Alright thank you very much both for the answers. It seems that there is a consensus that if I buy a JBL M2 it should be the way Harman was intended, with the Crowns and London BSS to have the full experience, otherwise it would be subpar. I was reading some posts in the minidsp website from people that use a miniDSP openDRC as a crossover for JBL M2 or another forum about using Audiolense Digital crossovers, with relatively good results, irrespective of which amplifier is used. However this is always subjective unless there are comparisons anywhere in this thread or others with custom solutions vs the full Harman chain? Am I also correct to say that Harman's ARCOS that is used in the JBL M2 Room Eq. is one step up even from Dirac? In the case of an external pre-pro or receiver higher up the chain for sound processing, is then common practice to bypass the REQ for any JBL M2 speaker, and let the Harman system do its own thing?

At the end of the day if M2s are an overkill for a medium sized room I might as well keep the 10 inch Tannoy, arguably an overkill too, rather than going to an 8 inch driver for the sake of simplicity. Unless even the JBL LSR708P with bass management and subs is also so much better for audio and home cinema?

Thank you in advance.
I'm not familiar with your Tannoys, but I know the 708p's are fantastic, with great dispersion creating a nice huge soundstage etc. The M2's I own with Crown I-techs and love, no doubt but if you want the next best thing, don't want to deal with a specific amplifier and required DSP settings, AND don't mind in-wall speakers, the JBL SCL-2's would be the next best thing. I believe it's the only other speaker in this particular family that uses a dual diaphragm CD. I've read incredible things about them, give them a look if the form factor will work for you.
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post #4179 of 4705 Old 11-24-2018, 07:51 AM
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Alright thank you very much both for the answers. It seems that there is a consensus that if I buy a JBL M2 it should be the way Harman was intended, with the Crowns and London BSS to have the full experience, otherwise it would be subpar. I was reading some posts in the minidsp website from people that use a miniDSP openDRC as a crossover for JBL M2 or another forum about using Audiolense Digital crossovers, with relatively good results, irrespective of which amplifier is used. However this is always subjective unless there are comparisons anywhere in this thread or others with custom solutions vs the full Harman chain? Am I also correct to say that Harman's ARCOS that is used in the JBL M2 Room Eq. is one step up even from Dirac? In the case of an external pre-pro or receiver higher up the chain for sound processing, is then common practice to bypass the REQ for any JBL M2 speaker, and let the Harman system do its own thing?

At the end of the day if M2s are an overkill for a medium sized room I might as well keep the 10 inch Tannoy, arguably an overkill too, rather than going to an 8 inch driver for the sake of simplicity. Unless even the JBL LSR708P with bass management and subs is also so much better for audio and home cinema? Thank you in advance.
If you buy the Crown amps with the processors built in, you don't need the BSS box. Beware noisy fans.

The current version of Sound Filed Management uses Room EQ Wizard (REW). Essentially it involves taking measurements of each subwoofer in the system at each listening position using REW and a calibrated mic. Those measurements are then sent off to Harman, where the number crunching is done. The calibrator gets back a long list of optimal settings ranked in order of evenness of bass vs. output. In Kevin's Voeck's system the second set of settings had the best balance of output vs. evenness. Those are then input into the SDP75 and voila - SFM!

All of this is in beta - they are still working out the particulars and what the costs will be. There is supposed to be a class for advanced dealers and calibrators sometime late this year / beginning of next.

I used Tannoy monitors years ago when I worked as a recording engineer. I don't know your exact speakers, but I would say if you value neutrality i.e. flat on and off axis response, you will not find many speakers as good as or better than the JBL LSR7 series. Plus, the compression driver and wave guide horn are an entirely different thing than a coaxial driver. Imaging and driver integration with proper wave guides is something you will not forget once you hear it done well. JBL and Revel excel at using science to produce some of the best measuring and sounding loudspeakers.

Dirac and ARCOS are for room correction EQ. I think you are still confusing the crossover and processor control needed for the M2's to operate properly with Room Correction EQ. You use the processors in the Crown amps or BSS London to handle the crossovers and processing to make the speakers work properly. Then you use Dirac or REW to smooth bass response in the room. I say again, M2's are passive speakers and a part of system that need to be treated as such. In a small room where you will not be playing them very loud, I think you would be getting way more speaker than you need. You need to sit far enough back from them for driver integration. And, research has shown, the use of multiple subs even with full range speakers helps smooth bass response in the room to more listening area. If you have monitor speakers that are flat down to 80Hz and let a pair of subs handle low frequency response below that, you save money on full range speakers and the high wattage power amps necessary to drive the woofers.
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post #4180 of 4705 Old 11-26-2018, 03:29 AM
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If you buy the Crown amps with the processors built in, you don't need the BSS box. Beware noisy fans.

The current version of Sound Filed Management uses Room EQ Wizard (REW). Essentially it involves taking measurements of each subwoofer in the system at each listening position using REW and a calibrated mic. Those measurements are then sent off to Harman, where the number crunching is done. The calibrator gets back a long list of optimal settings ranked in order of evenness of bass vs. output. In Kevin's Voeck's system the second set of settings had the best balance of output vs. evenness. Those are then input into the SDP75 and voila - SFM!

All of this is in beta - they are still working out the particulars and what the costs will be. There is supposed to be a class for advanced dealers and calibrators sometime late this year / beginning of next.

I used Tannoy monitors years ago when I worked as a recording engineer. I don't know your exact speakers, but I would say if you value neutrality i.e. flat on and off axis response, you will not find many speakers as good as or better than the JBL LSR7 series. Plus, the compression driver and wave guide horn are an entirely different thing than a coaxial driver. Imaging and driver integration with proper wave guides is something you will not forget once you hear it done well. JBL and Revel excel at using science to produce some of the best measuring and sounding loudspeakers.

Dirac and ARCOS are for room correction EQ. I think you are still confusing the crossover and processor control needed for the M2's to operate properly with Room Correction EQ. You use the processors in the Crown amps or BSS London to handle the crossovers and processing to make the speakers work properly. Then you use Dirac or REW to smooth bass response in the room. I say again, M2's are passive speakers and a part of system that need to be treated as such. In a small room where you will not be playing them very loud, I think you would be getting way more speaker than you need. You need to sit far enough back from them for driver integration. And, research has shown, the use of multiple subs even with full range speakers helps smooth bass response in the room to more listening area. If you have monitor speakers that are flat down to 80Hz and let a pair of subs handle low frequency response below that, you save money on full range speakers and the high wattage power amps necessary to drive the woofers.
Actually yes your answer clarified for me some things, I thought that ARCOS Room Correction and SFM was somehow implemented within the Crowns or the BSS Soundweb London processor, while it is done further up the chain, with the SDP-75 processor. As it is a Trinnov based one that would make any costs explode :-) I don't suppose that everyone using the M2 will have the SDP-75 too though!

My misunderstanding came from JBL M2 System integration website which mentions that some Room optimization is done within the Crowns/BSS as it states that: "Room optimization is achieved through the use of floating-point digital signal processing integrated into Crown iTech HD power amplifiers and BSS Soundweb London processors. HARMAN System Architect™ Software is included to provide external control of system EQ and tuning capabilities. Used in conjunction with external measurement hardware and software, the complete M2 tuning and room integration system addresses non-linearity in the room".

I think that a "gentler" start for me if I were to go the JBL M2 way, is to buy just a BSS London processor like the BLU-50 and temporarily bi-amp with the Parasound and a high crossover of 80Hz, suboptimal thought it might be, till at a second stage the Crowns can be purchased.

AVR: Marantz SR7011 (11.2 Atmos/DTS-X/Auro3D), Amps: Parasound HCA-2205a, Rotel rkb-8100, Front L/R: Tannoy DC10Ti, Center: Tannoy D750, Surrounds: Kef 3001, B&W 601S3
Heights: Focal Domes, B&W M1, Subwoofers: Tannoy TS2.10, Genelec HTS4
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post #4181 of 4705 Old 11-26-2018, 07:18 AM
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My misunderstanding came from JBL M2 System integration website which mentions that some Room optimization is done within the Crowns/BSS as it states that: "Room optimization is achieved through the use of floating-point digital signal processing integrated into Crown iTech HD power amplifiers and BSS Soundweb London processors. HARMAN System Architect™ Software is included to provide external control of system EQ and tuning capabilities. Used in conjunction with external measurement hardware and software, the complete M2 tuning and room integration system addresses non-linearity in the room".

I think that a "gentler" start for me if I were to go the JBL M2 way, is to buy just a BSS London processor like the BLU-50 and temporarily bi-amp with the Parasound and a high crossover of 80Hz, suboptimal thought it might be, till at a second stage the Crowns can be purchased.
"Room optimization is achieved through the use of floating-point digital signal processing integrated into Crown iTech HD power amplifiers and BSS Soundweb London processors. HARMAN System Architect™ Software is included to provide external control of system EQ and tuning capabilities. Used in conjunction with external measurement hardware and software, the complete M2 tuning and room integration system addresses non-linearity in the room".


I am not an expert on the M2 system, but others here are and may comment. I will look into it too. I'm pretty sure you would be fine using four channels of your Parasound amp and The BSS London processor. You may find you do not need more power, obviously depends on how loud you want to get.
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The BSS london and crowns do have the ability to do EQ, but it's all a manual process and you have to use external measurement system like REW or something else. Nothing is automatic.
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I would be interested in hearing your thoughts on the 708.
Probably best to read this.
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How loud are the DCIn amps? Are they about the same audible level as the iNuke 6000 fans?
I can't say I've ever heard one of them. I'm sure it's similar though.
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post #4185 of 4705 Old 12-01-2018, 07:46 AM
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I was reading some posts in the minidsp website from people that use a miniDSP openDRC as a crossover for JBL M2 or another forum about using Audiolense Digital crossovers, with relatively good results, irrespective of which amplifier is used. However this is always subjective unless there are comparisons anywhere in this thread or others with custom solutions vs the full Harman chain?
I use a pair of the miniDSP OpenDRC units and a pair of Yamaha amps (P5000S & P2500S) to drive my DIY M2 clones. It works well for me but I've never heard it done any other way. Keep in mind that there is nothing but wire between the LF amp and the 2216Nd driver so all 225 watts or whatever you have to work with is going to be used very efficiently. The BSS London BLU-50 (or similar) is Harmon approved so setup should be simpler and resale would be much easier than with a custom DSP solution. This may not be a concern until after I am dead since I don't see a speaker upgrade in my future.

Also look at the JBL VTX-F12 as a middle ground between the 708 & M2. I'm going to push them until someone tries them

Good luck with your hunt!
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post #4186 of 4705 Old 12-01-2018, 10:41 AM
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I use a pair of the miniDSP OpenDRC units and a pair of Yamaha amps (P5000S & P2500S) to drive my DIY M2 clones. It works well for me but I've never heard it done any other way. Keep in mind that there is nothing but wire between the LF amp and the 2216Nd driver so all 225 watts or whatever you have to work with is going to be used very efficiently. The BSS London BLU-50 (or similar) is Harmon approved so setup should be simpler and resale would be much easier than with a custom DSP solution. This may not be a concern until after I am dead since I don't see a speaker upgrade in my future. Also look at the JBL VTX-F12 as a middle ground between the 708 & M2. I'm going to push them until someone tries them
Good luck with your hunt!
The JBL VTX-F12 is meant to be used as a stage monitor or PA speaker. https://www.jblpro.com/ProductAttach...VTX_F12.v9.pdf

The 90 x 50 degree Progressive Transition Waveguide is different than the 708 and M2 horns. And, the response of the VTX starts looking a bit ragged off axis.

They probably sound good, just not sure how well they would match up with the 708 or M2.

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post #4187 of 4705 Old 12-02-2018, 07:00 AM
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Originally Posted by mobeer4don View Post

Also look at the JBL VTX-F12 as a middle ground between the 708 & M2. I'm going to push them until someone tries them

Good luck with your hunt!
Aside from the fact that they're a 12" woofer, they're not a middle ground. They will not have the SQ of the M2 or 708 and will not be a timbre match. I was told this by JBL Pro.

Of course if someone is willing to drop the cash to do a comparo I'm interested to read about it .
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post #4188 of 4705 Old 12-02-2018, 02:27 PM
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I use the BSS BLU 50 with my M2's.

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post #4189 of 4705 Old 12-02-2018, 02:57 PM
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I use the BSS BLU 50 with my M2's.
Just curious, does that BLU-50 have a noisy fan as well? I had the 80 for a minute and the fan in it was ridiculous. I expected no fan since it is the workaround.
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post #4190 of 4705 Old 12-02-2018, 03:27 PM
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Originally Posted by Gooddoc View Post
Aside from the fact that they're a 12" woofer, they're not a middle ground. They will not have the SQ of the M2 or 708 and will not be a timbre match. I was told this by JBL Pro.

Of course if someone is willing to drop the cash to do a comparo I'm interested to read about it .
The xover is way higher with these as well to prevent damage to the cd
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post #4191 of 4705 Old 12-02-2018, 04:16 PM
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Just curious, does that BLU-50 have a noisy fan as well? I had the 80 for a minute and the fan in it was ridiculous. I expected no fan since it is the workaround.
The BLU 50 doesn't have a fan and that's why I use it. ;-)
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post #4192 of 4705 Old 12-02-2018, 04:21 PM
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Amps to drive M2's

Dr. Toole has been following our discussion re: not using Crown amps, using other amps and the BSS processors. He offered this information:


"I see some discussion of the amps necessary to drive the M2. I looked into this when I was considering using them and found that the impedance of the D2 driver was about 20 ohms - you should check this! The importance of this fact is that a power amp rated into 8 ohms can deliver only about 40% of that into 20 ohms. The HF driver needs more voltage swing in order to deliver the same power. Obviously sensitivity enters into this calculation. All I am saying is that some of the discussion shows a lack of understanding in this respect. I think the woofer is nominally 6 ohms - a very conventional load."


Perhaps @notnyt or someone else can shed some light on the subject before we have folks attempting to use amps that are not up to the job. I can look into it further with my contacts at Harman/JBL but it might take some time. I know some folks are chomping at the bit to get M2's. We don't want any unhappy campers.
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post #4193 of 4705 Old 12-02-2018, 04:42 PM
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Originally Posted by Rex Anderson View Post
Dr. Toole has been following our discussion re: not using Crown amps, using other amps and the BSS processors. He offered this information:


"I see some discussion of the amps necessary to drive the M2. I looked into this when I was considering using them and found that the impedance of the D2 driver was about 20 ohms - you should check this! The importance of this fact is that a power amp rated into 8 ohms can deliver only about 40% of that into 20 ohms. The HF driver needs more voltage swing in order to deliver the same power. Obviously sensitivity enters into this calculation. All I am saying is that some of the discussion shows a lack of understanding in this respect. I think the woofer is nominally 6 ohms - a very conventional load."


Perhaps @notnyt or someone else can shed some light on the subject before we have folks attempting to use amps that are not up to the job. I can look into it further with my contacts at Harman/JBL but it might take some time. I know some folks are chomping at the bit to get M2's. We don't want any unhappy campers.

You just need an amp that can produce the voltage necessary to drive the high impedance load. Further complicating things is that there's a L-pad in front of the CD. That said, you don't need too much since the CD is quite sensitive.

If someone is adventurous, the D2 can always be wired in parallel to produce an ~8 ohm load, but then the L-pad and the output levels would need tweaking.

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post #4194 of 4705 Old 12-02-2018, 09:50 PM
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How loud are the DCIn amps? Are they about the same audible level as the iNuke 6000 fans?
If the iNuke 6000 is too loud to be in the same room, then maybe.

As for amplification, let's be realistic. It's a sensitive compression driver used at home. A stout headphone amp would probably do a credible job. A Parasound Zamp is enough to make you deaf. More important IMO is a gain match, to keep the expected balance between woofer and tweeter. Often that means way overpowering the tweeter.

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post #4195 of 4705 Old 12-03-2018, 04:34 AM
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Originally Posted by DS-21 View Post
As for amplification, let's be realistic. It's a sensitive compression driver used at home. A stout headphone amp would probably do a credible job.
I'd love to see an M2 powered by one of the THX AAA headphone amps.

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post #4196 of 4705 Old 12-03-2018, 08:26 AM
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JBL 'M2' Master Reference Monitor

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Originally Posted by Molon_Labe View Post
Do you own either the DCI or the M2?
Yes.

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Originally Posted by Molon_Labe View Post
That doesn't sound at all accurate, but I may be wrong. From what I have gathered, the M2 requires a lot of power on hand.

Let’s not confuse marketing hype with physical reality. Samsung wants people to think that to sell high margin amps along with the speakers! One caution is that some class D amps have crazy HF variations with impedance. An amp with such HF FR nonlinearity will not provide the intended frequency balance.

The important thing is to get the crossover voiced as intended. IMO that means Crown DSP-amp units or BSS processor and amps with identical gain structures (probably best to use the same model of amp for top and bottom).
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post #4197 of 4705 Old 12-03-2018, 08:54 AM
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Do not confuse power with voltage. See my response earlier. The HF section requires a good deal of voltage, but minimal power.

That says, you can easily drive the D2430K with a lower voltage amplifier, just not in the configuration that the M2 comes in from the factory.
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post #4198 of 4705 Old 12-03-2018, 12:01 PM
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Yes.




Let’s not confuse marketing hype with physical reality. Samsung wants people to think that to sell high margin amps along with the speakers! One caution is that some class D amps have crazy HF variations with impedance. An amp with such HF FR nonlinearity will not provide the intended frequency balance.

The important thing is to get the crossover voiced as intended. IMO that means Crown DSP-amp units or BSS processor and amps with identical gain structures (probably best to use the same model of amp for top and bottom).
So how worse would a theoretical solution be, of a BLU-XXX BSS processor and iNuke6000s, one handling the DSP/Crossovers and the other giving the raw power, instead of the Crown DCIs or any other amp, if the recommendation is to use lots of power because of the CD impedance? Inukes can be modded to have a silent fan on top. Of course the iNuke is a 300 pound amplifier versus the Crown being 5000 a piece, but is their main difference (only in their role as Power Amplifiers), apart from any build quality, the FR non-linearity you mention?

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post #4199 of 4705 Old 12-03-2018, 01:56 PM
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Originally Posted by Molon_Labe View Post
Has anyone run the DCI 300n on the M2? Crazy output is not my goal. I would like to stay in the DCI 300n range since the 1250 is 20 amp native, and I don't want to run 20amp (too much construction work). I know the 1250 can be run with a 15amp cheater plug, which is also an option. We are only talking 6db between the 1250n and 300n correct? The 708 is doing fine output wise. The M2 would be primarily for improved detail/clarity and a bit more headroom for movie dynamics since I am on the boarder line distance wise with the 708.
I am going run the SDA-4600 amplifiers (one each speaker) for a bit more power on my M2s. I will be able to load the EQ files for the M2 on those amps as well. The rest of the amplification for my Synthesis will be the DCi 8/300 amplifiers... I do not believe they require a 20 amps circiut.
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post #4200 of 4705 Old 12-03-2018, 03:10 PM
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The DCi 4 1250N works perfectly fine on 120VAC 10A breaker. I've done it for a while and even took load measurements with power on and while playing. Also, look at the spec sheet at 1/3 power as that's how Crown rates them....unless you have a ballroom you will not come close to those power specs. My DCi which is for sale comes plug-n-play.
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