Early Monolith III Info Needed

[amansker]

I am considering my first Martin Logan's on a budget. Starting to rebuild a system as I have been without for some years. Have had Acoustat 2+2, Apogee Stage, Magnepan MGIIIA, Sound Lab Dynastat and maybe this is a good time to tryout some MLs.

There is a local pair of the Monolith III passive xovers for sale with an early build date of 1991. Jim Power quoted $890 for new panels.

Were there any significant changes for the Monolith over its long production period? Any strong reason NOT to buy an earlier model? I know they are power hungry, big and heavy.

Not hung up on the Monoliths at all and would consider another local pair of Quest Z or even SL3 for the small listening room (14' x 18').

thanks.

 

[Jeff Zaret]

I would say JonFo is our resident expert when it comes to the Monoliths. I believe the Monolith panels are very similar to the CLS panels and this is what I paid for my panels. (CLS)

As far as the Quest Z or SL3, both a fine speakers and I think it will depend on your budget and your room will also be a deciding factor.

Good Luck on your journey and welcome.

Southern Ca??

Jeff

 

[kwr]

I would say JonFo is our resident expert when it comes to the Monoliths......

I would always defer to Jon's knowledge but as a long time user of Monolith IIIp I can make a couple of observations.

Your room is on the smaller side and would neccesitate nearfield listening as the Monoliths will not perform at all well near to a wall. I am sure with your experience with planars you have probably already thought of this.

The point that does leap to mind is that the Monoliths are like Maggies - they respond to power and can sound very ordinary if underpowered. We run a couple of Plinius SAl02's as monoblocs and are currently "suffering" with one as a stereo amplifier as one is out for a service. There is a big impedance dip low with the sealed woofer and another high as is usual with the electrostatic panel. Current is required. Consequently Monoliths are not the bargain they might otherwise seem.

Panel life is a vexed issue. We are still on the original panels of a '96 Monolith with no sign of problems. I have an easy reference in the house of another system with a pretty flat response from l5 Hz to beyond 20,000 Hz so am confident the panel is still working well. Other people seem to change their panels at a much lesser interval.

I am sure Jon will have further information.

Kevin

 

[amansker]

Jeff, I'm in San Diego County, but have ridden through Lancaster many times on the bike.

Regarding placement, I can get 3' behind both speakers, 24" to side wall on one and 18" to the other sidewall and be very comfortable with the placement. Previous speakers are typically toed in and I assume these would be also? Still, the Monolith's ARE really wide. OTOH it would be cool to have Monoliths. This placement has worked well with all the dipoles I have owned. The Dynastat soundstage was about 8' outside the speakers on Amused to Death (recorded with Q sound or something like that). Also through some notes 180 deg. to my ear. A typical recordings was closer to 2' outside the speakers.

On the other hand there are a couple of Quest Z for sale in the area. Those are probably more realistic for my small room and easier to drive. Is there any reason they were made for such a short time (2-3 years?)? Are the Z's less or more desirable than the Quest?

 

[JonFo]

Amansker,

While the room is on the tight side for a Monolith, it sounds like the distance from the wall behind them and to side walls is about right.

A couple of things about the Monilith IIIp that need to be acknowledged:

• A unit from 1991 will probably need a woofer update. This is easy to check, just drive that part of the speaker alone and listen for ‘flabby’ or distorted sound.
• When running in that small a room, some EQ will be needed to tame bass room modes and mid-bass dips.
• The panels are probably fine, at least for starters. I found the improvements after re-paneling quite worth the investment.
• The passive crossover sucks the life out of these speakers compared to even a cheap active.
  - BTW- I can sell you an Ashly crossover cheap if you just want to try something

I also usually counsel that a Monolith needs bi-amping. Even a cheap pro-amp on the woofer will sound better than a high-end amp driving the passive.
A good speaker processor is also a fantastic tool to tune this speaker to you room and is what I ultimately push other Monolith owners towards. Here’s a link to what one person stated about his experience.

Speaker processors perform crossovers, EQ, phase, but most importantly, it will do delay. A Monolith requires 1.75ms of delay on the panel to correctly time align with the woofer. In my experience getting all drivers in a speaker, and all speakers in a multichannel system to be perfectly time-aligned (accurate to a 0.5ms or better resolution) is a must for reference-level performance.

But all that said, even a stock Monolith can sound pretty awesome, but so can a Quest Z. Same size woofer, but slightly smaller panel. I’d think it would be a better fit for your size room.

Another thing is that with the rooms rear wall 15’ feet from the front of panels (either speaker model), you might want to disperse or diffuse the sound hitting that wall. But I’m sure you prior experience with planars or line-sources would show you that these things project a pretty deep ‘near-field’ and that the rear wall (behind the listener) is an important part of the equation.

 

[amansker]

Speaker processors perform crossovers, EQ, phase, but most importantly, it will do delay. A Monolith requires 1.75ms of delay on the panel to correctly time align with the woofer.

Maybe I should just buy some Bose? ha ha! I'm not a sound engineer and don't really "know" how much 1.75ms is in the real world or how much impact that has on the listening experience. I take it "most" people can hear the difference.

nother thing is that with the rooms rear wall 15’ feet from the front of panels (either speaker model), you might want to disperse or diffuse the sound hitting that wall.

You nailed that one. That is a major issue in the room and the most difficult to deal with. Ideally I would have 4' behind my listening seat, but that just isn't feasible.

VERY useful info. Thanks for taking the time to post. I'm seriously leaning towards a smaller ML - possibly the Quest Z.

 

[DTB300]

You nailed that one. That is a major issue in the room and the most difficult to deal with. Ideally I would have 4' behind my listening seat, but that just isn't feasible.

Most of the acoustic guru's out there on the forums (Ethan, Glenn, Bryan) do not recommend diffusion behind the seating position unless you sit much further from the rear wall - cannot remember the figure at this time. It was either a percentage or a minimum distance - I will try to find it again.

But every room is different and trying it out would be the best way to determine this.

Dan