Strange Monolith positioning: suggestions?

Hi all!

I need a suggestion about a particular speaker placement I have to choose in my room (ok, actually I don't think I can choose, you know, it hadn't been easy to convince my spouse to accept those monoliths, so I have to accept her, ehm, suggestions about placement...).

Instead of placing the speakers both on the same side of the room, I will place them diagonally.

Will the usual rule about distance from the back wall apply here? And what about the "1/3" rule about toe-in?

Thank you in advance for your suggestions!
Ciao
Paolo

P.S.: I've just installed new panels :music: and the trims are now in a wonderful european cherry!

Hi Paolo,

Congrats on the new panels!

Don’t the look so clean and shinny? I love the new look on the Diaphragms (they use modern vapor deposition process, even for replacement panels.).

As for placement, boy, you sure like a challenge

That diagonal location presents huge rear wave management issues. Without any further treatments, I can guess that the rear wave of both speakers is reflecting back into the space between the speakers, thereby giving a very narrow soundfield.

For this type of arrangement, I’d suggest putting a really big (72” tall x 24” wide) DIY absorber along the wall at the first REAR reflection point and damp all frequencies from 250hz on up. That means an absorber four inches thick, offset from the wall by 3”.
That would then mean your Monoliths would need to be another seven or eight inches further into the room.

Doing that will do two things:

1. Tighten up the bass, as the trapping of the lower, out-of phase frequencies from the rear will minimize dipole cancelations in the mid-bass. Monoliths really benefit from that, as their panels do go very low.
2. Absorb the high-frequencies enough that the rear wave reflected induced comb-filtering is minimized, and lower any rear wall reflected sound level enough that the predominant energy in the room is front wave sound.

Otherwise, look to place them symmetrically along the long wall of the room, paying attention to managing the rear wave dispersal so it is either long enough (>8ms before arrival) or damped enough through treatments.

One of the reasons everyone recommends pulling big dipoles out into the room is that that is an easy way to lengthen the arrival time of rear waves, and shorten those of the front. The delta between rear and front needs to be >8ms and preferably > 12ms.

And easy way to measure this is to measure the distance between front panel and listening position, and then measure the ‘billiard ball path’ of the rear wave as it bounces towards the listening position. The difference between the two should be >12 feet.

Sorry about the English measurement units, even though I grew up in a Metric country myself, I think in feet and inches these days. Google: “convert 12 feet to meters” for easy conversions.

JonFo said:

Google: “convert 12 feet to meters” for easy conversions.

Click to expand...

One of the best free conversion tools is located here...

http://joshmadison.com/article/convert-for-windows

Hi Jonathan,

yes they are really shiny! I've noticed that they use a new foam tape and, quite interesting, the conductive coating on the mylar doesn't cover all the surface, they left uncoated a strip near the foam spacers. I suppose this will increase a little bit the impedance in the capacitive region (i.e. high frequency) and move also the resonant impedance peak with the parassitic inductance parameters of the step up transformer further away from the audio band.
Anyhow, they are now breaking in, they are getting better and better every day! Next tweak, woofer replacement and biamping!
Back to my challenge: I was quite sure that this diagonal location wasn't the simpler solution, but, hey, we don't like simple challenges, do we?
I've noticed just what you are pointing out, a narrow soundfield. But i can't explain it just imagining the first-second reflection path: actually this path should be longer than using a "standard" placing. I think I'm missing something here...

Another question: the rear emission of the panel, since it is curved, should have a focus at the center of the arc of the panel. So I suppose it should be enough to put a "small" (or better not so wide) absorber where this focus is. Am I wrong?

Just as a reference, here are the speakers that the Monoliths have replaced: DIY hybrid esl speakers. They seem very small compared to the Monoliths!

Thanks, also to Steve for the metric-imperial converter!

Ciao

Paolo

Notwithstanding all of Jon's great suggestions, I think you might be surprised how GOOD corner-straddled placement can sound! I met Roger Sanders (designer of the Innersound electrostatic speakers, now Sanders Sound Systems) at RMAF last year, and he, in fact, advocates such placement! He did exactly that when demo'ing his RMAF system, and I assure you the imaging and soundstage were spectacular! The hotel room had very little acoustic treatment, so there's definitely something to be said for this approach. Here's a pic (from an older thread about Roger Sanders), illustrating his setup...
http://www.martinloganowners.com/forum/showpost.php?p=58021&postcount=3

I agree with both Jon and Sleepysurf here - yes, corner placement can sound FANTASTIC......, but you MAY be in for a little extra work fine-tuning placement.

So - don't worry about your wife's suggestions - just make the most of it. Take the time to play with positioning and any treatments your wife will accept, and I think you'll end up with darn good sound.

sleepysurf said:

Notwithstanding all of Jon's great suggestions, I think you might be surprised how GOOD corner-straddled placement can sound! I met Roger Sanders (designer of the Innersound electrostatic speakers, now Sanders Sound Systems) at RMAF last year, and he, in fact, advocates such placement! He did exactly that when demo'ing his RMAF system, and I assure you the imaging and soundstage were spectacular! The hotel room had very little acoustic treatment, so there's definitely something to be said for this approach. Here's a pic (from an older thread about Roger Sanders), illustrating his setup...
http://www.martinloganowners.com/forum/showpost.php?p=58021&postcount=3

Click to expand...

amey01 said:

I agree with both Jon and Sleepysurf here - yes, corner placement can sound FANTASTIC......, but you MAY be in for a little extra work fine-tuning placement.

So - don't worry about your wife's suggestions - just make the most of it. Take the time to play with positioning and any treatments your wife will accept, and I think you'll end up with darn good sound.

Click to expand...

Hey, this is a great news!!! I've played a little bit with placement yesterday evening: the sound changes completely moving the speakers only few cm! I still have to find the "golden point", and I know I have to be prepared to install some room treatment. So, some additional work, but I'm on the right track!

Is there on the web any guideline for this kind of placement or should I proceed with the good, old trial and error technique? With the help of some measurements of course, isn't it Jonathan?

Thanks guys for the encouraging words!

Ciao

Paolo

sleepysurf said:

Notwithstanding all of Jon's great suggestions, I think you might be surprised how GOOD corner-straddled placement can sound! I met Roger Sanders (designer of the Innersound electrostatic speakers, now Sanders Sound Systems) at RMAF last year, and he, in fact, advocates such placement! He did exactly that when demo'ing his RMAF system, and I assure you the imaging and soundstage were spectacular! The hotel room had very little acoustic treatment, so there's definitely something to be said for this approach. Here's a pic (from an older thread about Roger Sanders), illustrating his setup...
http://www.martinloganowners.com/forum/showpost.php?p=58021&postcount=3

Click to expand...

This is the same Roger Sanders who slags of MLs very convincingly on this You Tube clip, which is ESSENTIAL viewing. Question is, is he right?

Probably

http://www.youtube.com/watch?v=Vdf3VA06iSA

pidigi said:

Hi all!

I need a suggestion about a particular speaker placement I have to choose in my room (ok, actually I don't think I can choose, you know, it hadn't been easy to convince my spouse to accept those monoliths, so I have to accept her, ehm, suggestions about placement...).

Instead of placing the speakers both on the same side of the room, I will place them diagonally.

Will the usual rule about distance from the back wall apply here? And what about the "1/3" rule about toe-in?

Thank you in advance for your suggestions!
Ciao
Paolo

P.S.: I've just installed new panels :music: and the trims are now in a wonderful european cherry!

Click to expand...

Those are truly beauties! I bet they sound incredible!

User211 said:

This is the same Roger Sanders who slags of MLs very convincingly on this You Tube clip, which is ESSENTIAL viewing. Question is, is he right?

Probably

http://www.youtube.com/watch?v=Vdf3VA06iSA

Click to expand...

Well, he knows darn well his main competition is ML, so he needs a strong "selling point" to counter ML's "curvilinear" design. However, in casual one-on-one conversation he was careful not to denigrate ML's, (afterall, he'd love to sell all of us his pre-amps/amps). Frankly, regardless of whether you have a flat dipole design, or cuvilinear dipole design, room acoustics and speaker positioning have a significant effect on overall soundstage and imaging. The OP in this thread asked specifically about "diagonal" corner-straddling placement. IMHO, that is certainly feasible, but it will take trial and error to determine how best to do it.

OK - Roger was very "polite", as you say, and my use of the term "slag" was a strong way to put it, but he WAS having a go, be it subtle or not. Certainly flat ESL designs sound great, though - Quads, for instance. However, I know I prefer MLs... And I am English!

I wonder whether that You Tube video isn't worth a separate thread...

BTW: The Monoliths look awesome. Good luck eperimenting with them and use JonFo as your reference advisor!

Justin

Yesterday evening I had a listening session with a friend of mine (he will join the MLOC soon, he is near to buy a pair of Sequels) and with a lot of beer:rocker:, we tried different electronics and also different positions of the speakers. Now I have a reasonable wide soudstage, not huge but acceptable, but the most important thing is that there is a particulary deep image.
Guys, this panels are improving day after day.....

About Sander's theory, I must say that I partially agree with him: it's easier to deal with a highly directive loudspeaker regarding positioning and room threatment. But if you don't use diffusers you loose some ambience. Here in Italy we use to say that "the blanket is always too short" so is impossible to be completely covered.

Ciao!

Paolo

Monolith:rocker:
Monolith:bowdown:
Monolith:guitarman:
Monolith:clap:
Monolith

Max'd out on icons. Not enough (restricted by site allowance) to pay adequate homage, I am afraid.

Sander's & blankets & ambience points taken.

Volume to 11.

Enjoy.

Justin

BTW: Looking at this post I'd swear it was done by a screamager. As it is I am 45! Hmmm....