Back box for ceiling speaker

-BA-

-BA-

-BA-

Soldato
Joined
4 Sep 2005
Posts
2,794
Got my hands on a Monitor Audio C180-T2 for a good price ready to go in my bathroom ceiling.

What I am trying to now decide on is whether it needs a fire hood or a back box to improve sound. In the short term I don't plan on having the loft converted but will be having a floating floor put down which I want to be semi-permanent (i.e. if I then decide on a full loft conversion, to hopefully be able to keep the floor to keep costs down).

So if I decide on a fire hood for future proofing, how can I then go about improving bass from the ceiling speaker to that I am not leaking sound into the loft?

Really not clued up on this stuff. Do I need any particular speaker cabling or will bog standard do?
 
If you're handy with DIY then build a backbox from an MDF/Green Glue/MDF sandwich. Line the inside with fire retardant fabric fixed in place with more green glue. If you need fabric then give me a shout via trust.

If this isn't you then the next best option is an acoustically rated fire hood. This will help with some of the sound leakage as well as restoring the fire integrity of the ceiling.

The final off-the-shelf solution is a pre-made flexible fire hood made from a material similar to dynamat/acoustiblok. This will have excellent sound-leak reducing characteristics as well as providing so back-pressure for the bass response and being fire rated too. It;s an easy DIY fit, but budget £200 though.
 
When i was a teenager and had giant speakers in my car boot the boxes had to be a specific size for the speaker or the sound quality would suffer as there was too much or too little air to be pushed around, also some had ported vents others were sealed, im guessing the principles would be the same here if you was to build your own.
I can see how without a box some of the sound quality is going to dissapear into the loft cavity. How you find out these dimmensions, if its even relevant here i dont know, but maybe its worth thinking about before you make it and it sounds worse.
 
nick.lidgett said:
When i was a teenager and had giant speakers in my car boot the boxes had to be a specific size for the speaker or the sound quality would suffer as there was too much or too little air to be pushed around, also some had ported vents others were sealed, im guessing the principles would be the same here if you was to build your own.
I can see how without a box some of the sound quality is going to dissapear into the loft cavity. How you find out these dimmensions, if its even relevant here i dont know, but maybe its worth thinking about before you make it and it sounds worse.
Click to expand...

While in-car subs certainly need careful matching of driver and cabinet size, the same is rarely true of in-dash/in-door midrange units. You will hardly ever see a backbox when taking out the door mounted speakers in a car. Home audio inwall/inceiling speakers are designed to work in less-than-optimum situations. It's one of the design compromises accounted for in better brands of this type of speaker which is why good inceiling speaker cost the money they do. It's also why the ultimate performance level of the speakers is limited compared to s box loudspeaker.

As fir some of the sound leaking... Its more than "some". It is about half. Speakers radiate forward and backwards. The treble unit is more directional of course. However, treble isn't generally annoying in secondary zones. It is mid and bass that are the problem.
 
I'm doing this soon and hadn't even thought about back boxes :(
1 set in the bathroom and 1 set in the kitchen.

Loft above bathroom and bedroom above the kitchen, suppose the loft will be the main problem. Am I looking for any specific material to line these boxes?
 
lucid said:
While in-car subs certainly need careful matching of driver and cabinet size, the same is rarely true of in-dash/in-door midrange units. You will hardly ever see a backbox when taking out the door mounted speakers in a car. Home audio inwall/inceiling speakers are designed to work in less-than-optimum situations. It's one of the design compromises accounted for in better brands of this type of speaker which is why good inceiling speaker cost the money they do. It's also why the ultimate performance level of the speakers is limited compared to s box loudspeaker.

As fir some of the sound leaking... Its more than "some". It is about half. Speakers radiate forward and backwards. The treble unit is more directional of course. However, treble isn't generally annoying in secondary zones. It is mid and bass that are the problem.
Click to expand...

This is very enlightening, very well explained.
 
Really appreciate the feedback and thanks for the offer of fire retardant material lucid, I will likely take you up on the offer. Any idea on the dimensions I need to work on to get the most out of the speaker?
 
You'd need some data on the driver specs that goes beyond what you'll find on the brochure or in the user manual. Unless someone else here can assist, I think you trying to find this info will drive you nuts. So what I'd suggest is work to the constraints: joist width, ceiling void height. Then find a sealed box cabinet design for a similar size driver to yours (8") and use the volume of that as a guide to your final dimension of length. Also remember to have a look at the loft space for anything that might get in the way of the backbox such as pipes or cables. It would be a waste to design and build a box onlt to find that it wont fit because of a water pipe :D

Adding a couple of DIOT speaker cab build links: LINKY 1 LINKY 2
 
Last edited:
You must log in or register to reply here.
Back
Top Bottom