PMC IB2S IB1S users ! how do you listen to them ?

[livingstone]

Hello all !

i've just finished my room (yes an other one ) and i'm seting up my speakers,
a pair of IB2S with a Bryston 4BSST amp
my problem is about their height position

PMC recommend to have the mid drivers at 11° up to the listener ear for phase coherence between the 3 drivers,
so i've made some custom speaker stands to have them at the "right" height (at least the one advised by PMC)
soundstage and transient response like this is astonishing but the only problem is that when listening at 0° highs are a bit detached from the rest of the spectrum, and high sounds seems to obviously come from up ( of course they are ! ).

the overall sound get in balance only when looking at 11° up the horizon.

this is not a big problem, but ,
it's just a bit strange when i listen to a piece of jazz or classical extremly well recorded i feel like being in the concert hall BUT looking at and listening to the reality of these recordings at 11°.

i eventually thought to lower them a bit, but when i sat ears at 0° in front of the mid drivers it seems to me that the soundstage and overall sound is not so accurate and coherent,
so i'd like to share some listening experiences with other IB1/2S listeners/owners in the place,
how do you listen to them ? distance? height? experiences?
Carl ? Riccardo ?

[carlsaff]

Sorry... missed this originally. I'm in a 7' equilateral triangle with mine... a bit on the close side, but essentially a midfield monitoring setup. I have the mid drivers at ear level, and the speakers are toed in only slightly, firing over the furthest edge of my shoulders. I have no idea if this is "right," but my ears say this is the best arrangement for my room and listening position such as they are at the moment. In my next room, I suspect I will have them set up differently.

I had to prop them up quite a bit to get them to that height -- the stands they came with only boosted them 14". As they sit now, all of the drivers are in my line of sight. Coherence and imaging seem very good. Could they be better? Hard to say, but they certainly don't need to be to get good work done.

I may have to boost them a bit higher to try out the 11 degree setup you describe. If I do, I'll let you know what I find out.

[livingstone]

Hey Carl !

thanks for your reply


i'm at 7' too, and they 're on heavy custom stands ( 120Kg ) 3' high that should be for this listening distance 3,3' (a bit too high in my sense)

the 14" stands are the Hi Fi ones

if one day you can try them at this high it's really interesting but , it's about the position of the head when working on a sterling type console

here's the pmc drawings about the positionning, these are the one for the bigger ones BB5 and MB2 but they told me the principle was the same

sorry after uploading the schemo i found that i've made a mistake before it's 10° and not 11°

[Greg Reierson]

I have MB1s in an 8' triangle mounted at 10° elevation as recommenced. I've never noticed a problem with the high frequency image seeming unusually elevated. Do you have any early reflections that might be skewing your image?


Greg Reierson
Rare Form Mastering

[livingstone]

no early reflexion possible Greg,
i don't think so,

the room has a dedicated geometry and is heavily treated,
wooden made skyline in the first reflexion point on the ceiling and high density foam, in the lateral walls first point.
a reflexion from the ground ?
not usual for a such frequency
there's no furniture yet that could make any reflexion.
i actually work on a roll around rack as i haven't chosen yet if i wanted a central desk
or an open field with just 2 lateral "ergonomacousticaly" designed custom rack.

and about this thing with the highs it's just when i look at 0°,
if i look at a virtual line joining the two mids in the center wall the sound is marvelous, perfectly balanced
it's just when i look at 0°
then i feel the highs a little bit detached from the whole frequency range.

perhaps i've got an auditive halucination ?

[Riccardo]

Originally Posted by livingstone

perhaps i've got an auditive halucination ?

I moved the speakers until they sounded good. Uhm...I'll have to check the height and distances.

[sprout23]

i just got a pair of ib1s speakers and I'm wondering how everyone has theirs setup. Are you using PMC's recommended 10 degree mid range height. I need to get stands for them and I'm not sure how tall I should get. I'm thinking I'm going to get shorter stands and adjusted them as needed. I'm sitting about 7-8 feet away, and thats the same distance from speaker to speaker

[acorneau]

You could always try dropping the height to what you want and then tilting them back to achieve the recommended alignment of the drivers.

Just a thought.

[Edit: D'oh! Didn't look at the dates on the original thread. Nevermind!]

[StephenMarsh]

the room, your personal taste and the way you work will have everything to do with where they wind up. You've got PMC's take - go from there and use your ears. I've had mine in a number of different configs over the years in different rooms - never the same twice. FWIW - right now they sit pretty high and sound great.

--Steph

[Nescafe]

Old thread but got my attention since I almost finish my new room and it's time prepare some custom speaker stand. So do the IB2S user here have any update about the placement, height, toe in etc? I really curious with the height.....

I just calculate the stand using the formula above, if the distance between my work spot and speaker is around 2 meters, it's mean that the stand height will be around 2 m that it is sooo high and really suprised me.....

I just talk with my acoustician and he also suprised with my calculation result and, but he says everything is possible especially because the formula is from the manufacture, so we must make some experiment with the height, both listening and measurement. Do I make mistake with the calculation?

Any input will be very appreciated, it will become my starting point, will make some temporary stand using mdf.

Thank You

[SASMastering]

Bung them on stands. Get in front and simply move your head up and down play something you know intimately and let your ears decide where they sound right. Note the position. Thats what I did and got a carpenter to build stands to suit.
I have noticed no real vibration of my stands at 85dB SPL, but my dad is a good craftsman and built them well. (glued and screwed with 5 x uprights) mounted on neoprene rubber sheet 1cm thick and 2 x paving stones.

They are phenomenal speakers, clear, revealing, incredible low end response at all volumes, not perfect mind you.

Whatever you do, get it right, put them up and leave them where they are and never move them ever again.

[Nescafe]

@SASMastering
do You ever try the height using the formula in the post above?

[UnderTow]

Originally Posted by Nescafe

@SASMastering
do You ever try the height using the formula in the post above?

tan10 *2000 = 352.65

352.65 + 1250 = 1602mm (or 1.6m)

That is the is the position of the mid-range driver according to the model and formula above. That means the stands are even lower than that. Nowhere near 2m!

Alistair

[SASMastering]

Hi Nescafe, no.. I listened to how the speakers sounded. It took me quite a long while to get used to 3 driver speakers, I am still not convinced by them tbh, more drivers - bigger baffle more electric/acoustic problems for accurate reproduction.Though in the balance of things the presentation of scale for mastering over rules these issues by a fairly wide margin. I could never work solely on little speakers ever again, the compromises are too great.

[Nescafe]

Originally Posted by UnderTow

tan10 *2000 = 352.65

352.65 + 1250 = 1602mm (or 1.6m)

That is the is the position of the mid-range driver according to the model and formula above. That means the stands are even lower than that. Nowhere near 2m!

Alistair

Strange, my tab calculator result: tan10*2000= 1296.7216549

1296.721654918 + 1250 = 2546.72165

still got 2m stand from the calculation........

[lucabasano]

Ib1s here.
I've built a pair of stands for mine with exact dimensions of Pmc stands(take a look at pdf I've attached).
I'm working in a 2,4 mt equilateral triangle more or less,hypex amps,sound great.
hope it helps
luca

[UnderTow]

Originally Posted by Nescafe

Strange, my tab calculator result: tan10*2000= 1296.7216549

1296.721654918 + 1250 = 2546.72165

still got 2m stand from the calculation........

Time for a new calculator. :-)

Both the Windows calculator and the calculator on my phone give the results I posted above.

Alistair

[Nescafe]

@lucabasano,
Thank You for sharing the information, really appreciate it.

Originally Posted by UnderTow

Time for a new calculator. :-)

Both the Windows calculator and the calculator on my phone give the results I posted above.

Alistair

Yes.... right now didn't have the calculator with me other than my tab......

Thank You and Merry Christmas......

[Cubic Spline]

Originally Posted by Nescafe

Strange, my tab calculator result: tan10*2000= 1296.7216549

1296.721654918 + 1250 = 2546.72165

still got 2m stand from the calculation........

because it's set to radians instead of degrees !

[Nescafe]

Originally Posted by Cubic Spline

because it's set to radians instead of degrees !

Aahhh....IC , but can't change it to degree mode ha ha ha, default calculator from Galaxy Tab 8.9, must search another calculator in the market.......

Thank You.......once again Merry Christmas...

[parisminzer]

How do I listen to my 1b1's?
Loud. Very Loud!

Got them on the stock stands. Maurice from PMC here in L.A. tested the room and moved them how he saw fit.

Those guys are first class all the way.
Do not hesitate to hit then up if you're in the SoCal area!