Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Small room - speaker choice?

But even many small (non-DSP) speakers appear to benefit from being kept clear of boundaries. This seems to benefit stereo depth in particular, I suppose because early reflections are being delayed or dispersed.

Another lost post....

Someone suggested room treatment, I agreed.

The physical speaker size isn't an issue; frequency response is. The room size and shape will limit performance;

Square room = peaking response in the lower frequencies due to two dimensions being the same (room nodes).

Small room = changes the frequency of the peaks above; smaller the room the higher the frequency, in a very large room the node frequencies are so low as to not be a problem.

Small room = first reflection points are closer and therefore reflected sound will be closer (in time) to the original, this will lead to a blurred image (soundstage).

DSP room correction can help with the frequency response due to room nodes but cannot change the acoustical reflective properties of the room.

All the best,

Steve.

Thanks Steve - Saved me re-typing Besides, your response was far more eloquent!

Whilst the Meridian processor can correct for many things, the process is not without some acoustic "cost". Ideally it should be used only for fine tuning with minimal processing, not for trying to circumvent the laws of physics...

It is very rare to find that the ideal position for the tweeter and mid drivers is the same as the ideal positioning for bass drivers. The smaller the room, the more critical the latter is. (http://www.nutshellhifi.com/ME2txt.html scroll down)

The bass units on the 8k's are dual directional, this certainly helps in trying to even out the in-room bass response. Another advantage of the 8k's is their infinite baffle design, the bass response is achieved without the use of resonance ie ports. This enables the enclosure to behave correctly at a much lower volume level than for a ported speaker, late night listening etc.

So, if any of the "senior" Meridian speakers can be made to work in your room, the 8k's will have the best chance. BUT.. by the time you've positioned the speakers away from the rear and side walls (about 1m?) there will be precious little real estate left for the listening chair which itself needs to be away from the rear wall (behind) - unless the rear wall can be made acoustically dead.

More importantly there's very little space available for the soundwaves from each individual driver to merge together to form a credible soundstage and reproduce a point source (the theoretical ideal)

A room will have a natural bass gain of its own, and the smaller the room, the higher frequency at which this effect will commence. The following link may shed some light

http://www.linkwitzlab.com/rooms.htm

I suspect in your room any speaker that naturally achieves it's -3db point below 45Hz will start to overload the room. Traditionally this is the territory for smaller infinite baffle stand mounts - driven by Meridian electronics of course

There are other designs too that could suit the space better - dipole speakers for example would at least allow the speaker to be placed close (5cm) to the side walls due to their "figure of 8" dispersion - though you'd have to invest in sound panels to kill the back wave... the natural room bass gain would compensate for the traditionally weak bass response of this design.

Unfortunately your room is far from ideal for music reproduction and you have many physically induced acoustic issues to overcome.

Headphones of course would avoid all of these - a pair of AKG1000's or Stax Sigmas along with a subwoofer could produce a far more satisfying listening experience - I have mentioned these models as they avoid the "inside the head" soundstaging of traditional 'phones.

From my own experience, a pair of Stax with a B&W PV1 sub proved very satisfying and acoustically outperformed my G68/M33 set-up from some years ago by some considerable margin.

Of course, if you could move one of the walls by 3ft to create a 15' x 12' x 8' listening room then you'd be onto something... Speak to Tom (GMT) about moving walls, he understands...

Yes - but as you eluded to, you must look at the spread of the energy imparted to the room. The 33's and the 8k's will (roughly) follow each other down to a certain frequency. However, below 55hz (ish) the energy output of the 33's will fall away at 12dB/octave. The natural room gain will add the lower frequencies at the same rate, in effect creating a mechanical second order crossover.

The 8k's will continue their energy output to a much lower frequency. This output will be added to the lower frequency energy gain due to the room, creating a bass heavy overall response, in the same way as turning up a bass tone control would.

Of course one disadvantage of running a system at lower volumes is the loss of dynamic range - you lose the subtle details that make up so much of a 3D soundstage.

I see my post was lost (server crash ?)

I use 3 x 5200 (front) and 4 x 3100 (side and rear) and one SW1600.
The room is a room-inside-room construction of 3.2 x 4.2 x 2.4 meters (WxDxH)

There is plenty of low information in this room. It does not compare to a concrete box shaped room sound wise, as it hass in the horizontal plane only one 90 degree angled corner and no parrallel walls.

I have to say that practically speaking I concur with Bob.

My post got lost too. My question for the OP is what is the height dimension of this square room? I think it would be prudent to install floor to ceiling bass traps in the corners and treat the reflection points (side walls, back wall and ceiling) with some absorption and diffusion. I think this will be a tough room so try your existing speakers first.

Thanks to all, very interesting.

The ceiling is around 10 foot high from memory. The room can be knocked through to a bathroom which would make it around 15 foot.

How would that change my options? The only other difference from knocking through is the ceiling might need to be lowered by around a foot or so.

Well, you could listen to your music whilst in the bath, for one...

Thats a high ceiling, generally ceilings are about 2.4 metres (UK), so losing 0.3 metre in height is not a problem in my view.

If you extended, have you considered adding rears.

As someone suggested what other kit do you use with 3 x DSP5000DSPs? Do you listen to music mainly or video?

Regards I

A one piece sloping ceiling (ie not stepped) joining the two spaces would be an even better option from the acoustic perspective.

By increasing one of the room dimensions you will spread out the room resonance nodes across a greater frequency range, with each now much weaker than before.

If you google you'll discover ideal room dimension ratios which have been calculated with this in mind.

With the extension to 15ft you'd have roughly 3:4:5 which rings a bell from somewhere deep in the grey matter as being a good thing.

You must also think about the floor though - floor boards over joists create spaces in which sound will resonate. Look to wall mount your equipment for isolation, fill those under floor voids with loft insulation to increase the air density and consider very dense plinths (granite / marble) underneath the speaker.

Unfortunately this project is going to last longer than a weekend! Are you sure that headphones aren't the way to go?

(If you're up for a brain scramble http://www.linkwitzlab.com/modes1.xls)