Hi,
The 'household authorities' have decreed that I should be banished (along with dozens of boxes of hifi equipment, components, soldering and measurement kit, etc) to the garden shed. Incredibly, desperate to have the house looking like a home rather than a workshop, she even agreed to me getting a new, 20x12ft shed.
With a 10ft/3m internal height, I'm fitting ceiling speakers. (Available depth is only 5 inches/14cm). I'm using a simple sealed box approach. Speakers are full-range, with 8 inch main drivers. (I may add a sub at a later date so am also boxing off an enclosure suitable for a 10 inch sub).
The rough and ready approximations I've found so far suggest the following for sealed box designs:
Even though this installation is hardly Hi-Fi, I'm keen to do as good a job as I can. I'm after a tight, detailed bass sound, with good transient attack and articulation.
Are 0.7sq ft/20 sq l (8 inch) and 1.2 sq ft/34 sq l (10 inch) likely to be near the mark?
The full-range unit I'm considering is here
Thanks in advance!
The 'household authorities' have decreed that I should be banished (along with dozens of boxes of hifi equipment, components, soldering and measurement kit, etc) to the garden shed. Incredibly, desperate to have the house looking like a home rather than a workshop, she even agreed to me getting a new, 20x12ft shed.
With a 10ft/3m internal height, I'm fitting ceiling speakers. (Available depth is only 5 inches/14cm). I'm using a simple sealed box approach. Speakers are full-range, with 8 inch main drivers. (I may add a sub at a later date so am also boxing off an enclosure suitable for a 10 inch sub).
The rough and ready approximations I've found so far suggest the following for sealed box designs:
- 8 inch driver - 0.6 - 0.8 sq ft (17 - 22 sq l)
- 10 inch driver - 1.0 - 1.5 cu ft (28 - 42 sq l)
Even though this installation is hardly Hi-Fi, I'm keen to do as good a job as I can. I'm after a tight, detailed bass sound, with good transient attack and articulation.
Are 0.7sq ft/20 sq l (8 inch) and 1.2 sq ft/34 sq l (10 inch) likely to be near the mark?
The full-range unit I'm considering is here
Thanks in advance!
I think I understand the question, but why would you build boxes for “ceiling speakers”? If anything, that would reduce the bass. Speakers designed for walls, ceilings and adjoining room (infinite baffle) will have very little bass in an enclosure.
A quick overview of speaker designs:
http://en.wikipedia.org/wiki/Loudspeaker_enclosure
A quick overview of speaker designs:
http://en.wikipedia.org/wiki/Loudspeaker_enclosure
Thanks for the reply.
Unfortunately, I'm not sure I understand your answer.
What is it about a full-range driver (when mounted in a sealed enclosure) that results in reduced bass?Surely the standard laws affecting any driver mounted in a sealed enclosure applies?
What is it about drivers suitable for ceiling mounting that standard air loading effects don't apply?
(In the absence of T/S parameters, I'm presuming that it's high compliance will at least ensure that it's not completely unsuitable for sealed box loading).
Help!
Unfortunately, I'm not sure I understand your answer.
What is it about a full-range driver (when mounted in a sealed enclosure) that results in reduced bass?Surely the standard laws affecting any driver mounted in a sealed enclosure applies?
What is it about drivers suitable for ceiling mounting that standard air loading effects don't apply?
(In the absence of T/S parameters, I'm presuming that it's high compliance will at least ensure that it's not completely unsuitable for sealed box loading).
Help!
You wouldn’t want to stray too far away from a speaker’s purpose, especially without specifications.
E.g. I had a extra pair of ceiling speaker from a install, I thought they sounded great up in the ceiling so decided to try them in a bass reflex enclosure, even tuned them; it just didn’t work, no bass. I wasn’t that surprised, actually, I would have been more surprised if it worked.
They make subwoofers for “ceilings”, not that I know of any, but I do know they make them.
E.g. I had a extra pair of ceiling speaker from a install, I thought they sounded great up in the ceiling so decided to try them in a bass reflex enclosure, even tuned them; it just didn’t work, no bass. I wasn’t that surprised, actually, I would have been more surprised if it worked.
They make subwoofers for “ceilings”, not that I know of any, but I do know they make them.
Thanks again for the replies so far guys.
Odougbo, yes, drivers are made for ceiling mounting - I prvided a link in my first post to the ceiling speaker that this post is about.
I very much doubt that that driver is specifically designed for IB loading though. It would be the logical thing to do - but at this price level, I suspect that price dictated the design (hence polyprop cone, compliant surround, etc). I'm attempting to take advantage of those key characteristics in order to optimise the potential performance of this driver, that's all.
In any case, proper IB loading (and this is where I crash and burn in flames) would see a volume of air behind the cone at least equibalent (and even greater than) the volume of air forward of the cone (but as i say, that's just one of my personal frustrations with so many people wh kid themselves that they have an infinate baffle design, when in fact, what the have is, at best, an oversized sealed enclosure, at worst an oversized and inadvertantly ported enclosure. Rant over...
In fact, Odougbo, your experience of ceiling speakers failing to work well in a bass reflex enclosure just confirms my suspicions that ceiling speakers are designed with the key characteristics I've mentioned, making tem most suitable for use in a sealed enclosure.
Revboden - a 169 litre sealed enclosure for a 10' driver?!!!
Are you sure you've not made an error there? That's 6 cubic feet!
Everything I've read indicates that my 1.2sq ft/34sq l is nearer the mark. Would you mind explaining why 6sq ft/169sq l would work better?
Meanwhile, I'm going to contact the manufacturer to try and get T/S parameters. I strongly suspect that they themselves will have no idea however. (I'm pretty sure they will know the precise buld cost per unit though - it's all to easy to know the cost of eberything and the value of nothing, to paraphrase Oscar Wilde).
For what it's worth - image of the unit below:
Odougbo, yes, drivers are made for ceiling mounting - I prvided a link in my first post to the ceiling speaker that this post is about.
I very much doubt that that driver is specifically designed for IB loading though. It would be the logical thing to do - but at this price level, I suspect that price dictated the design (hence polyprop cone, compliant surround, etc). I'm attempting to take advantage of those key characteristics in order to optimise the potential performance of this driver, that's all.
In any case, proper IB loading (and this is where I crash and burn in flames) would see a volume of air behind the cone at least equibalent (and even greater than) the volume of air forward of the cone (but as i say, that's just one of my personal frustrations with so many people wh kid themselves that they have an infinate baffle design, when in fact, what the have is, at best, an oversized sealed enclosure, at worst an oversized and inadvertantly ported enclosure. Rant over...
In fact, Odougbo, your experience of ceiling speakers failing to work well in a bass reflex enclosure just confirms my suspicions that ceiling speakers are designed with the key characteristics I've mentioned, making tem most suitable for use in a sealed enclosure.
Revboden - a 169 litre sealed enclosure for a 10' driver?!!!
Are you sure you've not made an error there? That's 6 cubic feet!
Everything I've read indicates that my 1.2sq ft/34sq l is nearer the mark. Would you mind explaining why 6sq ft/169sq l would work better?
Meanwhile, I'm going to contact the manufacturer to try and get T/S parameters. I strongly suspect that they themselves will have no idea however. (I'm pretty sure they will know the precise buld cost per unit though - it's all to easy to know the cost of eberything and the value of nothing, to paraphrase Oscar Wilde).
For what it's worth - image of the unit below:
Attachments
There are ways to measure speaker parameters with computer programs and hardware, not that I know how. Good idea about contacting manufacturer, they may get back to you.
As a woodworker I shoot first then ask questions later; you could build a pair of test boxes and see how it goes. A sheet of ¾ MDF is about $30 bucks.
I’ve installed quite a few of ceiling and wall speakers (as a contractor) they work pretty well, a lot of bang for the buck. They have their limitations e.g. the mounting hardware can start to buzz, typically at higher levels.
The ceiling speakers I mentioned were bass reflex design. I just “copied” the size, and tuned them to the same box frequency. They ended up in the speaker bone yard.
As a woodworker I shoot first then ask questions later; you could build a pair of test boxes and see how it goes. A sheet of ¾ MDF is about $30 bucks.
I’ve installed quite a few of ceiling and wall speakers (as a contractor) they work pretty well, a lot of bang for the buck. They have their limitations e.g. the mounting hardware can start to buzz, typically at higher levels.
The ceiling speakers I mentioned were bass reflex design. I just “copied” the size, and tuned them to the same box frequency. They ended up in the speaker bone yard.
Hi,
Google for "measuring thiel small", or for starters try this link: Measuring Loudspeaker Driver Parameters
Regards,
Google for "measuring thiel small", or for starters try this link: Measuring Loudspeaker Driver Parameters
Regards,
I keep seeing this website coming up for T&S, a great site!
I have been trying to follow the step-by-step but, being non-English, it's pretty hard.
Is there a place with more info that you know of?
I have been trying to follow the step-by-step but, being non-English, it's pretty hard.
Is there a place with more info that you know of?
Revboden, that doesn't help, I'm afraid.
I'm just trying to get a rough and ready estimate of the approximate volume required for an 8 and 10 inch drivers in sealed enclosures, that's all. With no available T/S parameters (as predicted, the manufacturers have none) I realise that suggestions will all be very much 'ballpark', but that's better than nothing!
I've supplied my guesstimates (0.7 cu ft for the 8 inch driver, 1.2 cu ft for the 10 inch) I'd be truly grateful if some of you could provide some too - it would (hopefully) reassure me that I'm in the right ballpark. As I say, I'm after a taught and articulte sound rather than a loose, Ill-defined 'boom'.
I'm just trying to get a rough and ready estimate of the approximate volume required for an 8 and 10 inch drivers in sealed enclosures, that's all. With no available T/S parameters (as predicted, the manufacturers have none) I realise that suggestions will all be very much 'ballpark', but that's better than nothing!
I've supplied my guesstimates (0.7 cu ft for the 8 inch driver, 1.2 cu ft for the 10 inch) I'd be truly grateful if some of you could provide some too - it would (hopefully) reassure me that I'm in the right ballpark. As I say, I'm after a taught and articulte sound rather than a loose, Ill-defined 'boom'.
Logical thinking;
If it looks like a ceiling speaker, if it is marketed like a ceiling speaker and if the brand’s main activity is ceiling speakers and conference systems, how big are the chances that:
If it looks like a ceiling speaker, if it is marketed like a ceiling speaker and if the brand’s main activity is ceiling speakers and conference systems, how big are the chances that:
- You are dealing with a ceiling speaker?
- You are dealing with T/S parameters tuned for ceiling purposes?
Hi Bart West-VL.,
Post #10: There are just too many to list them here, another good one is on Brian Steele's Subwoofer DIY Page: The Subwoofer DIY Page - Measurements
Hi Lenin21,
It obviously is a ceiling speaker, so when in doubt it might be best to mount them without an enclosure. Alternatively, if you don't have the T/S parameters for your driver, and if you don't want to take the time to measure them, just build the largest sealed box that will fit the available space, stuff it loosely with polyfill. That would be my enclosure estimate.
Regards,
Post #10: There are just too many to list them here, another good one is on Brian Steele's Subwoofer DIY Page: The Subwoofer DIY Page - Measurements
Hi Lenin21,
It obviously is a ceiling speaker, so when in doubt it might be best to mount them without an enclosure. Alternatively, if you don't have the T/S parameters for your driver, and if you don't want to take the time to measure them, just build the largest sealed box that will fit the available space, stuff it loosely with polyfill. That would be my enclosure estimate.
Regards,
Sorry to say I'm with the other guys. better to get an old set of boxes or buy better drivers. most ceiling speakers are pretty bad, if you are lucky you get a set designed for the gap between floors; some need cubic meters to work in IE the whole roof space.
6 cubic feet (180/200 liters ) is a fairly small box as far as my speakers go but SWMBO is starting to put her foot down where my sub woofers (9 of them ) are concerned
6 cubic feet (180/200 liters ) is a fairly small box as far as my speakers go but SWMBO is starting to put her foot down where my sub woofers (9 of them ) are concerned
If it looks like a duck and quacks like a duck - it aint necessarily a duck...
Djim, I wish things were that simple.
Cigarettes used to be marketed as good for you, by companies who insisted that they were good for you, supported by glossy ads, featuring glowing, healthy-looking people making it clear that they were good for you. What are the chances that cigarettes are good for you? The reality of course, was (both for cigarettes and budget speakers) making large bucks, as cheaply as possible, using the thinest, most scientifically baseless marketing imaginable.
The idea that these speakers have been specifically designed to exploit the likely volume of air to be found in floor/ceiling cavities in an average room is as baseless as the idea that cigarettes are good for you. I'm fairly sure that we are talking about a manufacturing company keen to exploit a market opportunity by having 'ceiling speakers' in its range. its clear to me that hey have simply taken advantage of the economies of scale that being a large manufacturer brings and cobbled together a full-range driver, using cheap and cheerful components, mounted it in ceiling mounting hardware and then marketed it as a 'ceiling speaker'! If I'm right, the manufacturer wouldnt have the foggiest idea what the T/S parameters are, of course. Guess what? They have absolutely no idea what the T/S parameters are. They do for all their other (more expensive) models, but clearly, the design of these units as ceiling speakers doesnt extend beyond fitting the driver in some ceiling mounting hardware.
Look, I realise I'm being a bit strident here - but this is becoming slightly frustrating. I'm asking for some ballpark recomendations for 8 and 10 inch drivers with compliant surrounds, mounted in sealed boxes, thats all. I realise that no T/S parameters means it's kinda ballpark, but please, go on - just take a punt! Give me a loose range! Tell me that I should stick to the lower or upper range of the volumes I gave in my first post!
Please, lets not postulate any longer on whether the drivers were specifically designed for IB use - let's just pretend that they are suitable for sealed box use and contribute 'safe zone' guestimates.
Djim, I wish things were that simple.
Cigarettes used to be marketed as good for you, by companies who insisted that they were good for you, supported by glossy ads, featuring glowing, healthy-looking people making it clear that they were good for you. What are the chances that cigarettes are good for you? The reality of course, was (both for cigarettes and budget speakers) making large bucks, as cheaply as possible, using the thinest, most scientifically baseless marketing imaginable.
The idea that these speakers have been specifically designed to exploit the likely volume of air to be found in floor/ceiling cavities in an average room is as baseless as the idea that cigarettes are good for you. I'm fairly sure that we are talking about a manufacturing company keen to exploit a market opportunity by having 'ceiling speakers' in its range. its clear to me that hey have simply taken advantage of the economies of scale that being a large manufacturer brings and cobbled together a full-range driver, using cheap and cheerful components, mounted it in ceiling mounting hardware and then marketed it as a 'ceiling speaker'! If I'm right, the manufacturer wouldnt have the foggiest idea what the T/S parameters are, of course. Guess what? They have absolutely no idea what the T/S parameters are. They do for all their other (more expensive) models, but clearly, the design of these units as ceiling speakers doesnt extend beyond fitting the driver in some ceiling mounting hardware.
Look, I realise I'm being a bit strident here - but this is becoming slightly frustrating. I'm asking for some ballpark recomendations for 8 and 10 inch drivers with compliant surrounds, mounted in sealed boxes, thats all. I realise that no T/S parameters means it's kinda ballpark, but please, go on - just take a punt! Give me a loose range! Tell me that I should stick to the lower or upper range of the volumes I gave in my first post!
Please, lets not postulate any longer on whether the drivers were specifically designed for IB use - let's just pretend that they are suitable for sealed box use and contribute 'safe zone' guestimates.
OK For a quick and dirty solution it really doesn't matter if the box is big or even really big.Volume for Qtc=1 may be 30 litres but making the box 200 litres may only give you a Qtc of 0.7. When in doubt make the box bigger, it really doesn't matter that much with cheap drivers for which there is no data
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