Film-Tech Forum ARCHIVE: Meyer Sound Acheron Designer vs. JBL M2

This is topic Meyer Sound Acheron Designer vs. JBL M2 in forum The Afterlife at Film-Tech Forum ARCHIVE.

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Posted by Haris Ellahi (Member # 9941) on 06-02-2017, 04:20 PM:

For a home theater, would you guys prefer an Acheron Designer based setup or a M2 based setup?

Posted by Haris Ellahi (Member # 9941) on 06-13-2017, 04:26 PM:

Any comments/opinions on this? Basically want to get some feedback on how the Acheron models compare to the M2.

Posted by Jay Wyatt (Member # 8768) on 06-15-2017, 05:12 PM:

Both are highly regarded and probably more than sufficient for any home theater environment.

For a commute to the grocery store, would you prefer a Ferrari or Aston Martin?

Posted by Daniel Schulz (Member # 1881) on 06-16-2017, 02:04 AM:

Both good choices. Need more info though; what is the size of your theatre? Will it be fully soundproofed such that you'll able to play at full reference level, if that's what you're after?

Powered speakers can be awesome (and your two options are great examples of going this road) but create interesting issues with wiring a home theatre. Are you sure you don't want to go with passive speakers with all of your amps in a rack or equipment room?

Posted by Haris Ellahi (Member # 9941) on 06-16-2017, 12:11 PM:

Thanks for the replies.

The room has yet to be built but will have dimensions that are roughly 20 ft long x 14.5 ft wide x 9.5 ft high. It will most likely be made of concrete all around so sound leakage should be at a minimum. I'm looking to achieve reference level (at a minimum) with no stress or strain. The equipment rack will be placed outside the room so that is not an issue. I actually prefer powered/active speakers as you get the "complete package" instead of having another variable in the mix (i.e. amplifiers) that can alter the final result in ways that might not always be favorable.

Coming back to the topic, I've read from others that the M2 is far ahead in terms of technology and design when compared to the Acheron speakers. The horn on the Acheron models looks quite simple whereas the M2 has a unique waveguide. I've also read reports from those who compared the Meyer Sound Amie monitors to the new JBL 7 Series monitors that the Amie is quite directional (i.e. it sounds as if the sound is coming from the speakers) whereas with the JBL 7 Series they sound "invisible" with a much larger sweet spot and much better imaging. Not sure what this means when comparing the bigger brothers. I actually currently own the JBL LSR305 monitors with the matching LSR310S subwoofer for my desktop PC setup. I can attest to the great imaging and overall sound quality I get out of these.

Posted by Daniel Schulz (Member # 1881) on 06-17-2017, 01:19 AM:

I think you are leaning in the right direction. Do you have a JBL Synthesis dealer you can tap? M2s for the LCR and then some corresponding JBL for all the surrounds, with the corresponding Synthesis electronics supporting whole thing, is a good way to go. The JBL Synthesis ARCOS room correction and especially their Sound Field Management system for handling multiple-subwoofer bass management, are without peer.

Posted by Jarod Reddig (Member # 6363) on 06-17-2017, 05:29 PM:

Id go with the M2s and matching surrounds from the same line.

Posted by Haris Ellahi (Member # 9941) on 07-12-2017, 03:44 AM:

While the 705 and 708 match the M2 and are designed to be used with the M2 for immersive applications, how much of a "disadvantage" would I be at if I were to mate M2 LCRs with JBL SCS 8 for all surround and ceiling speakers in order to save cost? Will there be a noticeable tonal/sound quality shift when sounds pan from the M2 speakers to the SCS 8s? I know that JBL used the M2 as LCR and SCS 8 for all surround and ceiling speakers during their CEDIA demo in 2014 or 2015 so I guess it can work fine but would still like some feedback.

Posted by Steve Guttag (Member # 268) on 02-12-2018, 08:59 PM:

It looks like I'm going to audition an M2 for my new home theatre. My theatre will be a mix of JBL and QSC and definitely done with a commercial cinema type layout.

Posted by Daniel Schulz (Member # 1881) on 02-13-2018, 03:47 PM:

quote: Steve Guttag
It looks like I'm going to audition an M2 for my new home theatre. My theatre will be a mix of JBL and QSC and definitely done with a commercial cinema type layout.

Nice! Also have a look at the newish JBL SCL-2. Similar compression driver and waveguide, but an in-wall speaker, good for a baffle wall setup.

Posted by Marcel Birgelen (Member # 6801) on 02-13-2018, 04:37 PM:

I'd prefer a JBL SCL-2 compared to an M2, simply because it's better suited for a baffle wall setup. The form factor of the M2 is more suited for a classical studio setup. If you're not planning a baffle wall and just want to put your speakers on a stand behind the screen, I guess the M2 is fine though.

Both are a bit overpriced though and if you can't get them at a steep discount, I'd consider other options with a bit more bang for the buck.

Posted by Steve Guttag (Member # 268) on 02-13-2018, 06:27 PM:

Not baffle wall ready? Oh yeah? When one is making the cabinet, anything is baffle wall ready!

This is our mock up so we get the ports tuned just right and everything tweaked...then the real speakers will be made from that. And yes, they will be fitted with a full baffle wall, though, at 5-across, they will nearly be their own baffle.

For the subwoofer...I'm thinking maybe a variant of the SUB18. Definitely 2269 driver(s). How can one not like a driver that can take 4000-watts and can deliver down to 18Hz?

Posted by Marcel Birgelen (Member # 6801) on 02-14-2018, 02:28 AM:

You didn't mention you're building your own cabinets, you can hardly call it an authentic M2 anymore then. [Wink]

I agree on the SUB 18, in our screening room we're using custom-built subs based on two of the JBL 2269H drivers, which we recovered from an MD7. One should actually be enough for the entire room though. Positioning them correctly in tandem was harder than we initially thought and the added value for MDA formats like Atmos for having two of them is not really worth it.

Posted by Steve Guttag (Member # 268) on 02-14-2018, 07:44 AM:

The thing with the 2269 is it isn't efficient. It is only a 92dB sensitivity driver so you need a massive amount of power to light it up, even in a small space. Using two just bumps you to 95dB. Sure, the 2269 can take massive power but with just one driver, you'd need a massive amplifier, probably run on 220V to avoid tripping breakers (120V is most common here but, since it is in my house, 240V would be easy to have). Two drivers just makes more sense from a sensitivity standpoint.

Did you hear the MD7? If so, what did you think? I know it is supposed to be for "Dance" rooms and all but they horn like nature of it has me curious about it for some applications.

I'm actually considering making the sub a sealed box.

Posted by Marcel Birgelen (Member # 6801) on 02-15-2018, 02:08 AM:

quote: Steve Guttag
The thing with the 2269 is it isn't efficient. It is only a 92dB sensitivity driver so you need a massive amount of power to light it up, even in a small space. Using two just bumps you to 95dB. Sure, the 2269 can take massive power but with just one driver, you'd need a massive amplifier, probably run on 220V to avoid tripping breakers (120V is most common here but, since it is in my house, 240V would be easy to have). Two drivers just makes more sense from a sensitivity standpoint.

Yes, you can't just use any amp to drive it. It has to be a real powerhouse. Right now we're using two Crown Xti 6002s in bridged mono, which are a bit out of place, since all the other amps are QSC amps. But the Crowns are the best "bang for the buck" we could find and are performing well.

Both amps have their own 20A breaker at 230V and are on different phases, although besides the initial power-on of those amps, they'll not draw anything near that 20A@230V in production. Still, it's good to have some headroom.

Although it was not the initial idea, we decided to give the screening room a separate fuse box and run thee phases from the main switchboard to the room. It saved a lot of headaches and a lot of wiring in the end.

quote: Steve Guttag
Did you hear the MD7? If so, what did you think? I know it is supposed to be for "Dance" rooms and all but they horn like nature of it has me curious about it for some applications.

I did hear it in action at a friend who does many live productions. He also has the gear to actually drive it at 16kW peak... It's really a massive speaker and driven near maximum in a relatively small room, it's hard to distinguish anything anymore with your fingers in your ears. [Wink]

The thing is though, compared to most of those generic PA subs, it has a very clean sound, not the typical "boomy" bass you'll get from your average PA sub, but more like the clean bass you'd expect from a cinema or studio setup. The horn-loaded design certainly helps to achieve it. I think you could easily use the MD7 in an actual cinema setup, if you don't need to integrate it into the baffle wall. You'll need to find the appropriate amp to drive it though.

quote: Steve Guttag
I'm actually considering making the sub a sealed box.

A sealed box is probably the easiest way to handle it, you don't need to bother about getting the bass reflex ports right. You won't be able to go down all the way to 16~18 Hz without those ports though, like the SUB18. We ended up with two ports per sub with almost the same dimensions as the SUB18 and about the thickest MDF available around here for the cabinets.

Posted by Steve Guttag (Member # 268) on 02-15-2018, 06:59 AM:

Why not? Have you looked at the plot of the 2269 in a sealed box? With a single filter, one could pretty much choose their LF response. Sure, it will take substantial power at those low frequencies but that is something that the 2269 can do quite well and with a 3 cubic foot enclosure, it would be tiny. in fact, with the 12.5" driver depth, it almost a challenge to make the box that fits it. You, pretty much, need the face of the box be just the driver. With two of them and enough power (which I don't think will be a problem), I could have it go as low as the room would allow and given the size of the room, one couldn't hear the 18Hz, if the movies actually had it recorded. Given it is just a six sided box, I'm tempted to try it just to see how it goes.

Posted by Marcel Birgelen (Member # 6801) on 02-16-2018, 02:46 AM:

We did do a quick plot with the port holes closed, although it was not really a sophisticated test. The enclosure has more headroom than the one you envision, so the results won't be exactly the same. What I remember is that there was a difference of roughly +6 dB at 20Hz between the port-holed end-result and the one with the ports closed. At 30Hz, the difference would be about 2 dB and at 40Hz it would be about the same.

Besides the increased frequency response in the LF part, one of the concerns of a sealed box we had also was the cooling of the voice coil. Although we're not using it anywhere near maximum, you're still putting quite some energy into it. With the two port holes, you at least create a limited amount of circulation.

I'm eager to hear about your results in a tight fitting sealed enclosure though. I don't consider any design final and a sealed box design could definitively save some space and increase the accuracy of the bass even more.

Posted by Steve Guttag (Member # 268) on 02-16-2018, 06:49 AM:

Since it is essentially a zero cost option (for the box, presuming I have th drivers), I'm going to give it a go.

Posted by Steve Guttag (Member # 268) on 08-29-2018, 11:28 AM:

quote: Marcel Birgelen
I'd prefer a JBL SCL-2 compared to an M2, simply because it's better suited for a baffle wall setup. The form factor of the M2 is more suited for a classical studio setup. If you're not planning a baffle wall and just want to put your speakers on a stand behind the screen, I guess the M2 is fine though.

The baffle wall for my "M2s" going in. SUB18+ also won the subwoofer selection. I'm not clustering them since I have way more sub than the room needs and will use them to augment the front row of Atmos surrounds in addition to LFE.

The M2 has REALLY impressed me. When the final version of "our" M2s were done and I was able to finally put a pair up and do some more critical listening to them. They are pretty incredible. You'll hear EVERYTHING that was put into the recording. Every detail or flaw. Listening to some CDs was an entirely new experience. I've never had speakers that imaged as well as these and all five of them have that characteristic. Until now, my L250s were the best speakers I had heard (liked them better than the later 250Ti so I never updated them) but the M2s have proven their ability to me. I've never heard a better speaker than them.

The SUB18s are just frightening. I'd need a much bigger room to really get the most out of them yet they sound awesome outside too!

Posted by Marcel Birgelen (Member # 6801) on 09-01-2018, 05:50 AM:

Looks like a pretty nice buildout for a private screening room.

With so much firepower in that space, I hope you don't have picky neighbors or they're sufficiently far away. [Wink]

Just out of curiosity, how are you going to mount the five custom made M2s?

Also, have you settled on a screen yet? I guess you'll be going for a microperf screen?

Posted by Steve Guttag (Member # 268) on 09-01-2018, 06:10 AM:

If you look at the bottom of the cutouts in the baffle wall, you'll see it is a platform so the M2s will sit on that. The whole face of the baffle wall will have duct liner attached, natch.

As for screen, it is a Severtson SAT-4K (woven) with the proper black backing fabric to prevent re-reflects and be acoustically transparent.

The room is being built to be as soundproof as practical. It is in the basement so it is entirely below grade so the outer-most walls are foundation cement. All of that will or is lined with fiberglass. Any inside wall will be thick with 2x6/2x8 studs and lined with fiberglass and I'm going for asymmetrical drywall layering too. The ceiling joist bays have Rockwool (by Roxul), two layers deep to help it from transferring to the floor above. The HVAC vents that feed the room above are being replaced with insulated versions to cut down on them being a "microphone" from downstairs. Then a drop ceiling with fiberglass above that. In fact, there will be so much sound absorption that I'm going to experiment once the drywall goes up on the inside as to how much/thick fiberglass to use on the walls to get the RT-60 times desired. I'm NOT seeking an anechoic chamber. One can have too-dead a room and make hard to listen to things. The back wall will get 2" of fiberglass and then the side walls will be adjusted until the right RT-60 range is achieved and then the fabric will be applied.

Posted by Marcel Birgelen (Member # 6801) on 09-01-2018, 04:10 PM:

On the picture it's hard to see how deep the platform is. Did you connect it to the baffle wall? And aren't you afraid about vibrations being transferred to the baffle wall construction that way?

Besides loads of mineral wool, we've ended up putting in a bunch of mass-loaded vinyl as sound barrier. The problem with mass-loaded vinyl is though, that it reflects sound back to quite some extend, even if you're going to put it in between two layers of drywall. In order to get the RT60 timings right we covered large parts of the walls and especially the back wall with melamine foam panels, which we itself covered with permanently flame-retardant fabric.

In order to stop the sound from traveling via the HVAC system, simply installing "sound proofed" flexible ducts wasn't enough, we installed special noise dampening couplings, which effectively did the job of entirely eliminating any audible sound coming via the HVAC system. The great thing is, it worked both ways. You don't hear the HVAC system or any noises coming via it, in the room either, or you must put your ears almost besides a vent.

Do you have sufficient height and room in the back to build a proper projector room?

I'm pretty interested in your opinion on the Severtson SAT-4K screen. We've tried a woven screen before (don't know the brand anymore, but it definitly wasn't Severtson), but the results were less than stellar. On the first row, during bright scenes, everything looked like a painting. [Wink]

What's the planned distance between the screen and the first row?

And... are you planning to install a movable masking system?

Posted by Steve Guttag (Member # 268) on 09-01-2018, 08:17 PM:

The speaker platform was actually the first part of the "wall." The rest of it was built from that and there is sufficient room behind that for servicing the speakers/wiring and such.

As for vibrations, not a chance. A) These M2s were made extra dense so they don't (or barely) vibrate to begin with...even playing painfully loud. To keep the M2 specs, one only need keep the internal volume the same...these are wider/taller (and heavier) due to the extra density. But, as if that wasn't enough, they have rubber feet to isolate vibrations from/to them. I could have put in the genine spikes but opted for rubber vibration isolators.

We'll see how well things isolate and adjust accordingly. There is a tremendous amount of potential SPL in the theatre and, after hearing the M2s, I intend to listen to music in there too. They are pretty spectacular. We'll see what comes up and from where. The realities are, while we watch a lot of movies, it isn't like it is going to be in use all of the time and if everyone in the house is watching the movie, who cares if it leaks some audio. I'll also have a night-time mode to cut back on the bass and cap the level. We're going to make a good-faith effort at sound control and see where we are.

There are two I-beams whose bottoms are 8-feet above the floor and they are 8-inches tall. The rear 1/3 of the room will be 1-foot above the front so that leaves about 7-feet to the ceiling in the rear.

Projection room? None. The projector will hang in unfinished space behind the theatre and project through the rear wall.

As for masking...of course. Why would I want to lower myself to commercial level? [Wink]

I also plan on a grand drape. The masking will likely be manual while the grand drape I hope to motorize. With both, it won't be the cost but the space for the motor.

Distance from screen to front row is about 10-feet.

Posted by Marcel Birgelen (Member # 6801) on 09-03-2018, 01:24 AM:

quote: Steve Guttag
I could have put in the genine spikes but opted for rubber vibration isolators.

I prefer some good rubber pads. The higher friction will ensure your speakers remain where they are.

quote: Steve Guttag
We're going to make a good-faith effort at sound control and see where we are.

In our case, we had to consider the nearby office spaces. Also, we've taken it on as a challenge, which isn't easy, since you're looking at enormous SPLs and an extremely broad frequency range. We also have a nearby train track, which produces some interesting vibrations and noises at all kinds of frequencies.

quote: Steve Guttag
Projection room? None. The projector will hang in unfinished space behind the theatre and project through the rear wall.

So, that automatically makes the unfinished space the projection booth? [Smile]

I think it is paramount to keep the projector out of the screening room. The amount of noise and heat is otherwise difficult to get rid off.

Are you going for a full DCI system or are you settling for some non-DCI projector and playout system? I guess there are no plans to support film?

quote: Steve Guttag
I also plan on a grand drape. The masking will likely be manual while the grand drape I hope to motorize. With both, it won't be the cost but the space for the motor.

We've decided not to install a drape or curtain, simply because it would become a too tight fit with our rather bulky masking system. We've got individual motorized masking for the top and bottom, the left and right share one motor as they're always symmetrical. Our screen is roughly 2:1, it maximizes the potential of the room regarding sight-lines, but I like to move scope a bit "up", so the bottom masking extends more than the top masking.

quote: Steve Guttag
Distance from screen to front row is about 10-feet.

I'm really interested if it works out for you. I'd prefer to replace our screen with a woven screen too, but the weaves really need to be invisible, otherwise the picture will be more horrible than on a vinyl screen with visible perforations.

Posted by Steve Guttag (Member # 268) on 09-03-2018, 10:40 AM:

The system will not be DCI at all, though, at this point, I probably could put together a DCI compliant system...I'm not exactly "Belair" material. As for as sources, strictly consumer (Laserdisc, DVD and Blu-ray). The sound system will be cinema-esq. If the movie has an Atmos mix, I'll be able to decode it to its fullest. For the rest, 5.1/7.1. It is a QSYS sound processor for getting everything where it belongs and manipulating as I see fit. I even "built" a 3->5 channel "spread" decoder in QSYS. Preliminary tests were promising.

I don't know if the curtain will make it at first but that is definitely in the plans. A theatre looks so unfinished without one. Plus I don't like showing a naked screen like that. Also it will reduce HVAC born dirt when the space is not in use.