Question In Ceiling Speakers Enclosure / Back Box - Monitor Audio C265IDC & C380IDC

damo_s

Active Member
Hi,

Could anyone who installed in ceiling speakers for Atmos - and in particular C265IDC or C380IDC please advise on the following:

1. Did you use any enclosure / back box for the speaker for protection / sound insulation and if so what was it? MA sell a dedicated MDF box but it us quite expensive. I live in a bungalow with loft insulation and thin plywood flooring above ceiling, so some kind of box seems like a good idea.

2. Is enclosure normally needed? I imagine it would protect the speaker from dust, reduce sound leakage into the loft and also result in improved sound quality in the listening room?

3. Did you consider installation of CP version of the above speakers instead (closed back CP-C380-IDC)? Not sure if it would be a better call, enclosure on CP version has relatively small volume, so it may not sound as good as open back with larger MDF box?

I decided to purchase one of the above MA speakers, but know very little about the installation procedures. I will do a lot of reading, but want to make sure that I order the right speakers in first place.

I think I have good enough DIY skills and required tools, so could make the MDF box. I just want to make sure that I get the best sound possible and avoid any beginners / silly errors.
I would be tempted to go for closed CP version of the speaker but I am concerned that it may sound inferior with very little air to breathe.

I would much appreciate any useful tips regarding installation of these ceiling speakers.
Many thanks in advance.
 

damo_s

Active Member
I've made some sound proof boxes for my CT265idc's - check my build thread (in my signature)

Alternatively, you could use hoods instead.
Thanks Adam, wow that was quick.
I looked at Hoody 2, they do not come cheap either.
That is a nice thread and build, congrats on progress to date and I will follow with interest!
I like what you have done with the backer boxes and will try something similar. I initially thought about noggins and fixing the MDF box to them, but was concerned about vibrations / decoupling.

Just a couple of queries.
Did you make them the same size as MA boxes?
Do you think the boxes you made will provide a noticeable benefit in terms of improved SQ over the hoods?

Many thanks
 

adam-burnley

Distinguished Member
Just a couple of queries.
Did you make them the same size as MA boxes?
Do you think the boxes you made will provide a noticeable benefit in terms of improved SQ over the hoods?

Many thanks
Yes I used the dimensions of the MA boxes.

My primary concern is sound proofing, and the boxes will do a much better job than hoods would. I don't know if either would make the speakers sound worse, after all, the sound is being pushed down and away from the speaker.

I know some fellow forumites that also have the 265s, haven't used anything at all, other than stuffing a bit of rockwool around them.
 

damo_s

Active Member
Hi Adam,

Thanks, I will use the same dimensions.
With regard to CP and IDC version only the 380 / 8" is available and the diameter with grill is even larger than non CP, so I will just make enclosures.
Also, just phoned Monitor Audio and from conversation it seems that non CP in a larger box should also have deeper bass, spec confirms this. I therefore rule the CP380IDC out.

This leaves me with C265IDC and C380IDC dilemma.

My understanding is that the 380 has a better tech RST driver and 8" vs 6.5" goes noticeably lower (45Hz vs 60Hz). My GXFX serve surround duty and they go "only" down to 60Hz and have 6.5" driver. At no point I thought, damn I wish my surrounds had more bass and went down to 45Hz. I expect Atmos effects channels to be even less demanding on the speaker than the surround channels?
My Platinum floorstanders also have 6.5" drivers, no speaker in my setup has 8" driver.
So it seems that the only thing that should make me go for C380IDC is the better tech of the driver (RST) so it would be more "in line" with my Platinum and Gold setup.

I am gravitating towards C265IDC at the moment, Monitor Audio also suggested this speaker to me and said that C380IDC would obviously also work but the benefits for Atmos duties may be not that significant when using sub and crossovers anyway (they have however, suggested C380IDC to another forum member)

BUT - On the other hand my PLC150 does go down to 45Hz so C380IDC would go as low as the centre, C265IDC would go as low as the surround GXFX. Do I match 45Hz of the centre channel or 60Hz of surrounds?

ANOTHER BUT - I do not want to do all this time consuming work and then wonder what if I had C380IDC?

Therefore I have a question for you please.
What made you go for 265 rather than 380?

Many thanks
 

adam-burnley

Distinguished Member
In a nutshell, I was advised by more than one knowledgeable person that the 265s are more than adequate for Atmos duties. Yes the 380's are better on paper, but unlikely to deliver better SQ in real-world use.

Also, don't forget that it is generally recommended to set a high crossover for Atmos speakers - 120Hz is not unusual. Obviously this is down to personal preference as well though, and you may prefer a lower crossover, but in most cases, most let the sub(s) handle LFE and set the LCR crossover to 80Hz.
 

damo_s

Active Member
Thank you Adam, I like your answer. I set surrounds crossover at 80Hz with fronts down to 60, maybe less. I need to check when I'm back home. I really need to read more about atmos setup.
I don't want to go too low for for ceiling as cracks will start to appear [emoji5]️, so it seems c265idc x4 is the way forward.

I wish they made C365idc with RST driver though...

I shall be installing them in January so I'll let you know how they sound.
 

The latest video from AVForums

Podcast: Philips OLED+935 impressions, Denon AVC110 Review, Film Reviews, News and More...
Top Bottom