Evening all, i'm new to the game , looking to make a slim line centre speaker. hoping for something that is about 900mm wide, 180 tall and 350 deep, handle music and a/v. Planning to make a unit that looks and hopefully sounds good too, solid timber-which might be a challenge!
Ok so aethetics might be dominating practicality but it has to fit into the decor and be able handle a weighty lcd tv on top of it.
All units i see for retail, are about 400-500 wide.
Also that when building speakers you need to start with the drivers specs, so i might have the cart before the horse?
Can anyone suggest a plan for this sort of build?
cheers
Ok so aethetics might be dominating practicality but it has to fit into the decor and be able handle a weighty lcd tv on top of it.
All units i see for retail, are about 400-500 wide.
Also that when building speakers you need to start with the drivers specs, so i might have the cart before the horse?
Can anyone suggest a plan for this sort of build?
cheers
Horizontally aligned speakers are a total PITA. How do you get wide, uniform dispersion without lobing or colourations from a speaker that is only good at vertical dispersion?
If you sit slightly off-axis, it's like watching an old LCD with a narrow viewing angle, where the image that you see with one eye is darker than what you see with the other eye and it screws with your mind.
180mm is not much room for a tweeter to be positioned above or below a midwoofer, so I'd either:
1) change the design and make room,
2) use an array of closely spaced 1" ~ 3" wide-range drivers on a curved baffle to improve dispersion.
Edit: at the moment, I'm liking the idea #2 for a curved horizontal array using e.g.: Aurasound or HiVi drivers. If the speakers are small enough, you could probably have separate arrays of say, 19mm tweeters and 3" ~ 4" midranges. I'm not sure how it would sound though.
If you sit slightly off-axis, it's like watching an old LCD with a narrow viewing angle, where the image that you see with one eye is darker than what you see with the other eye and it screws with your mind.
180mm is not much room for a tweeter to be positioned above or below a midwoofer, so I'd either:
1) change the design and make room,
2) use an array of closely spaced 1" ~ 3" wide-range drivers on a curved baffle to improve dispersion.
Edit: at the moment, I'm liking the idea #2 for a curved horizontal array using e.g.: Aurasound or HiVi drivers. If the speakers are small enough, you could probably have separate arrays of say, 19mm tweeters and 3" ~ 4" midranges. I'm not sure how it would sound though.
thanks for the thoughts lech
ok so how far above the woofers would the tweeters need to be,? entirely? vertically aligned? why exactly do the drivers need to be on axis- i dont quite get the physics of this? and why are there so many designs using horizontally aligned drivers in mtm configurations? there are some designs that appear to have 'critical acclaim' —or at least have been designed by some guys who from their rep and resume should know how to get a decent sound? George at North Creek and the 'vision centre' is one example. Time heading Acoustic Research etc sounds like fair experience. Of course this is assuming AR has some credibility??... They're using some hi end components at least...
perhaps this query and home theatre in general is too far an excursion from the motivation of this forum...
ht is a compromise in some ways i guess
still i'm hoping to find a design that can marry form and function fairly well and that may include increasing the height of my planned enclosure,
anyone else care to tender a plan that might fit these specs?
ok so how far above the woofers would the tweeters need to be,? entirely? vertically aligned? why exactly do the drivers need to be on axis- i dont quite get the physics of this? and why are there so many designs using horizontally aligned drivers in mtm configurations? there are some designs that appear to have 'critical acclaim' —or at least have been designed by some guys who from their rep and resume should know how to get a decent sound? George at North Creek and the 'vision centre' is one example. Time heading Acoustic Research etc sounds like fair experience. Of course this is assuming AR has some credibility??... They're using some hi end components at least...
perhaps this query and home theatre in general is too far an excursion from the motivation of this forum...
ht is a compromise in some ways i guess
still i'm hoping to find a design that can marry form and function fairly well and that may include increasing the height of my planned enclosure,
anyone else care to tender a plan that might fit these specs?
I'd stick with the time proven MTM personally. There is little reason to attempt to reinvent this particular wheel IMO.
The MTM laid on its side is used because it is the only pratical method of getting several drivers positioned near the center of the TV. Theoretically we would like the speakers mounted dead center of TV screen. You can do MTTM or WMTMW or other variations.
One of the most over looked parts of the center channel is matching the sonic qualities of the center to the main speakers, especially if you will be using your HT as a means of playing SCAD & DVDA.
Another option, one that is dear to me at the moment, is to use a couple of full range speakers. It certainly simplifies the job. I'm doing exactly that in a FR-T-FR config with a simple 1st order electrical x-over. I'm basing it on the wicked little 4.5" CSS 125's.
The MTM laid on its side is used because it is the only pratical method of getting several drivers positioned near the center of the TV. Theoretically we would like the speakers mounted dead center of TV screen. You can do MTTM or WMTMW or other variations.
One of the most over looked parts of the center channel is matching the sonic qualities of the center to the main speakers, especially if you will be using your HT as a means of playing SCAD & DVDA.
Another option, one that is dear to me at the moment, is to use a couple of full range speakers. It certainly simplifies the job. I'm doing exactly that in a FR-T-FR config with a simple 1st order electrical x-over. I'm basing it on the wicked little 4.5" CSS 125's.
garymtb said:
At the crossover frequency the midwoofer/s and tweeter will play the same tone at the same amplitude, but the phase will vary depending on the listening angle. Depending on the angle there can be either constructive or destructive interference.
Because people's ears are usually at about the same height, they tend to be more sensitive to horizontal phase effects rather than vertical ones.
Like binarywhisper said: practicality is the issue, and people often forget to match the centre speakers with the Left and Right ones.
interesting, seem to recall some of that phase and interference theory from high school physics.
reviews on the css 125s do sound very complimentary.
even to the point that the tweeter might not be required, i guess hearing the things is the best solution.
nice looking units too. they talk about the things being tested in a 200litre enclosure... how would a larger enclosure affect the preformance of the speaker—i was under the impression there was an optimum volume which produced the best results, and a smaller or larger box would be less satisfactory.
the box i propose would be around 37 litres the css cones and maybe a tweet would make for a good looking unit...
what are the characteristics you would try to match between centre and mains, loudness can be adjusted, so is it more a question of tone, and if so how best to match?
reviews on the css 125s do sound very complimentary.
even to the point that the tweeter might not be required, i guess hearing the things is the best solution.
nice looking units too. they talk about the things being tested in a 200litre enclosure... how would a larger enclosure affect the preformance of the speaker—i was under the impression there was an optimum volume which produced the best results, and a smaller or larger box would be less satisfactory.
the box i propose would be around 37 litres the css cones and maybe a tweet would make for a good looking unit...
what are the characteristics you would try to match between centre and mains, loudness can be adjusted, so is it more a question of tone, and if so how best to match?
garymtb said:
For a start, get the Loudspeaker Design Cookbook by Vance Dickason as it goes into details on centre speakers as well as all other aspects of loudspeaker design. It also includes a complete HT design which you can use as a reference.
Pick some drivers from Peerless, Vifa, SEAS (Scan-Speak too expensive for this exercise) which are readily available in Australia then start doing some searching. There's always a debate on TM vs a sideways MTM but they are not as bad a made out and as long as you are not too far off axis it's not a problem (just grab the best seat). The key is to get the tweeter as high as possible and the woofer as low as possible while maintaining centre distances to suit the crossover.
I personally used to use a vertical TM for a centre speaker but recently had to compromise with a angled TM that's shown in the pic. The key feature is the vertical height distances between the drivers with a short distance between the tweeter and woofer. This one uses a Peerless mid-woofer and Vifa tweeter chosen for it's sound and small faceplate.
If you are going down the path of music using 5.1 (wise?), then all speakers need to be the same where HT can have compromises. I do use the same mid-woofer on all my 6.0 speakers but have 3 different tweeters.
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garymtb said:
well the best way to match tone is to use the same drivers for all of the speakers in the system but it goes further. The same cabinet design and materials as well cross over design and components.
That is where the MTM design really shines. A single design can fill all 5 positions in the 5.1 setup giving a near perfect tonal match.
You don't have to make the enclosure for the center channel larger just because it physically needs a bigger box to support the TV. You can make the same required enclosure inside of a larger box.
If you have an excellent ear and the time to experiment you can build something that will be a match for existing speakers but it requires experience and time.
The reasons for the emphasis on matching your center to the rest of the speakers can to "some degree" be explained by using two different brands of speakers for your front 2 channels. Just on the surface the idea makes no sense at all. We go though a great deal of trouble to either build or acquire a pair of speakers that image well and present a decent sound stage. That cannot be done if we are using a variety of different components and designs for each individual speaker in our system and to a lessor degree the same can be said when you use differing sets in our home theater.
As mentioned I am using the CSS 125's for my main channel but I didn't mention that I am building a complete 5.1 system using the same drivers. Its a great first DIY project as all the materials, including plywood and x-over components, for the entire project is under $1000 taxes in. If I don't like it or wish to move up the food chain of DIY I doubt I will have much trouble selling them to one of my friends that are always complaining about their 1 box systems.
hey guys thanks very much for your input, its beginning to make sense. I still need to get my head around the various specs of individual drivers and the resulting acoustic properties, as well as the requisite electronic components that go inside the box, crossovers etc i'm a a little vague on some of this so I have been thinking of the cookbook and will probably get one.
Yes nice work on the speaker rabbitz, i hope mine turn out so well.
Binary whisper I checked out the cssfr125s and they get a pretty good rap! You say you'll go with a tweeter as well but the specs say they're good for 20,000hz? they'll make a good looking setup.
how many of the 125s are you getting for under a grand?
Yes nice work on the speaker rabbitz, i hope mine turn out so well.
Binary whisper I checked out the cssfr125s and they get a pretty good rap! You say you'll go with a tweeter as well but the specs say they're good for 20,000hz? they'll make a good looking setup.
how many of the 125s are you getting for under a grand?
garymtb said:
well I already own two of them so that is helpful.
The thing to do if you are interested in reading up on the CSS 125's is to hit a few sites like Planet 10, RAW, Timsters site and there is some more that don't come to mind right at the moment.
http://www.planet10-hifi.com/
http://www.timn8er.com/
gotta go, I'll be back though
alright well I'm back.
I'm using tweeters for a number of reasons. The CSS 125's are pretty amazing speakers as full rangers. I have a pair in my living room right now and they are fine as a primary pair of speakers as long as you don't expect rock concert volume and you listen to mostly jazz, acoustical stuff and vocalists.
They do have a fairly narrow sweet spot and I would consider them to be predominantly a near field solution when used on their own as a full ranger. The sound stage is kinda small as well.
All that said they will not work for me as full rangers. I do listen to a lot of jazz and acoustical stuff but I also listen to a lot of M. Mason, R.Zombie, NIN, Pantera, Disturbed, Exies as well as a ton of blues and bits of classical, a lot of classic rock and more.
I have experimented with them using a variety of drivers and hacked together cross overs and have come to some conclusions. My intention is to use them as a very wide range mid-range.
the older WR125's drivers can be had for $57.00 ea and thats what I'm going to use for the front and centers. I need 6 of them for a total of 342 plus tax and shipping. They do not do the highs as well as the 125FR's but I'll be using tweeters so that is fine. The front channels with be bipoles and the center will be a MTM with the tweeter raised up as far to the top as possible.
I have a pair of FR125's and I will use them as full rangers for the rear channels. 2 of them are $160 plus tax.
That is 502 plus tax and shipping. So now I need to come up with 3 tweeters and the parts to make a 1st order xover's and the wood to build the cabinets. I have quite a number of matched 12" woofers lying around so I'll save some money there. I don't need expensive tweeters as I plan on them only covering from some where around 8 to 10k and up.
So that the deal. I'm hoping that for around $1000 I can build a kick butt 5 speaker set that will do everything reasonably well. I have spent 100's of hours reading and experimenting and I am convinced it a very acheivable set of goals using this method.
you could save the time and trouble and just buy them from here
http://www.alegriaaudio.com/RosaLCR.htm
here is a review of the same speakers. Tim has used a very nice quality tweeter, $57 bucks each if memory serves and I've read enough of his posts and reviews of his speakers that I am thinking of buying the same tweeters.
http://www.affordableaudio.org/AlegriaAudioRosa.pdf
http://forum.ecoustics.com/bbs/messages/47077/186180.html
Hope I'm being helpful and not just thread jacking ... you did express an interest
I'm using tweeters for a number of reasons. The CSS 125's are pretty amazing speakers as full rangers. I have a pair in my living room right now and they are fine as a primary pair of speakers as long as you don't expect rock concert volume and you listen to mostly jazz, acoustical stuff and vocalists.
They do have a fairly narrow sweet spot and I would consider them to be predominantly a near field solution when used on their own as a full ranger. The sound stage is kinda small as well.
All that said they will not work for me as full rangers. I do listen to a lot of jazz and acoustical stuff but I also listen to a lot of M. Mason, R.Zombie, NIN, Pantera, Disturbed, Exies as well as a ton of blues and bits of classical, a lot of classic rock and more.
I have experimented with them using a variety of drivers and hacked together cross overs and have come to some conclusions. My intention is to use them as a very wide range mid-range.
the older WR125's drivers can be had for $57.00 ea and thats what I'm going to use for the front and centers. I need 6 of them for a total of 342 plus tax and shipping. They do not do the highs as well as the 125FR's but I'll be using tweeters so that is fine. The front channels with be bipoles and the center will be a MTM with the tweeter raised up as far to the top as possible.
I have a pair of FR125's and I will use them as full rangers for the rear channels. 2 of them are $160 plus tax.
That is 502 plus tax and shipping. So now I need to come up with 3 tweeters and the parts to make a 1st order xover's and the wood to build the cabinets. I have quite a number of matched 12" woofers lying around so I'll save some money there. I don't need expensive tweeters as I plan on them only covering from some where around 8 to 10k and up.
So that the deal. I'm hoping that for around $1000 I can build a kick butt 5 speaker set that will do everything reasonably well. I have spent 100's of hours reading and experimenting and I am convinced it a very acheivable set of goals using this method.
you could save the time and trouble and just buy them from here
http://www.alegriaaudio.com/RosaLCR.htm
here is a review of the same speakers. Tim has used a very nice quality tweeter, $57 bucks each if memory serves and I've read enough of his posts and reviews of his speakers that I am thinking of buying the same tweeters.
http://www.affordableaudio.org/AlegriaAudioRosa.pdf
http://forum.ecoustics.com/bbs/messages/47077/186180.html
Hope I'm being helpful and not just thread jacking ... you did express an interest
not at all binary whisper, i like th detail in the discussion and welcome any comments where people have experience, wont be concerned at alternative viewpoints either. yeah cost is a factor esp here in oz the fr125s go for around $140 each. how much wil the xos cost (dont bother with exchange rates).
I'll be doing the centre plus rears for starters and then maybe look at matching front mains if i cant stand the mismatch. the guy from alegria has some nice looking gear. the matching units plus a sub would sort any limitations at the bottom end.
Ok so at least mw plus tweeters required
gotta go
I'll be doing the centre plus rears for starters and then maybe look at matching front mains if i cant stand the mismatch. the guy from alegria has some nice looking gear. the matching units plus a sub would sort any limitations at the bottom end.
Ok so at least mw plus tweeters required
gotta go
garymtb said:
Look here http://darcheraudio.com.au/shop/index.php?main_page=product_info&cPath=1_2&products_id=1
well like everything in audio x-overs, even simple 1st order electrical, can very huge in price. I could build the 3 x-overs for as little as $20 total or I could spend $750 for the same design.
I haven't decided on what I will use. Rather I intend on doing a budget and I will build the x-overs based on the amount of money left over .... which isn't likely to be much.
My approach will continue to be experimental which means I will start with a little as possible and then start adding to it or improving on it till I reach a point where the return is not worth the investment.
This is an easy approach to use with x-overs, especially if you mount the x-overs in an external enclosure. My goal is to learn as much as possible during the process of this project. Even if I'm not satisfied when its all said and done the amount I will have learned will far make up for the time invested and I should have no difficulty selling the results to friends or family to recoup my investment in preparation for moving on to my next project.
I haven't decided on what I will use. Rather I intend on doing a budget and I will build the x-overs based on the amount of money left over .... which isn't likely to be much.
My approach will continue to be experimental which means I will start with a little as possible and then start adding to it or improving on it till I reach a point where the return is not worth the investment.
This is an easy approach to use with x-overs, especially if you mount the x-overs in an external enclosure. My goal is to learn as much as possible during the process of this project. Even if I'm not satisfied when its all said and done the amount I will have learned will far make up for the time invested and I should have no difficulty selling the results to friends or family to recoup my investment in preparation for moving on to my next project.
hey Rabbitz, you're up late. Well they lok the goods and seem to be getting great reviews from all i can read. I like the look of them for a pair of surround speakers.
At the moment I will probably opt for the same strategy as Binarywhisper low cost incrementalism. I have been thinking about the centre speaker situation while all this discussion's been going on. I just cant spare the cash now to lash out on a stack of drivers so I'll reconfigure what I've got. Which is a pair of Richter Mentors plus a couple of Jaycar Respionse 8" elacement drivers (sounding a hell of a lot better than the original drivers whose foam surrounds had disintegrated when i bothered to look! The simple project of replacing these drivers got me onto this path—and now I cant get off!
My plan (comments please) is to come up with a set of decent looking speakers for my ht using some Aussie hard wood (maybe veneer). Love the timber grain look.
I'll repair the Richter drivers, replace them in the black (low saf) cabinets, stand them end on end and enclose in timber to make a very solid and fairly low profile long centre speaker out of the two. This will have the desired timber grain blah blah blah (this house has timber everywhere) so cosmetically at least it will be ok. The Richters have one 8" and a tweeter in each and I may replace one of the tweets with a mid.
Then, replicate the Richter boxes in the same timber as the new centre, copy the fairly simple xo units and install the response drivers and similar tweeters. I figure the design is ok and sounds like a silk purse to my sows ear.
Then I think a pair of the fr125s in same timber small rear speakers (or wr125s plus tweets)
I'm confident in my woodworking ability, but will doubtless learn a lot in terms of sound and how to get it.
(Maybe add a sub later in the piece too)
If anyone would like to comment, go for your life (maybe save mine) Questions at the moment are how to wire the joint Richters .
At the moment I will probably opt for the same strategy as Binarywhisper low cost incrementalism. I have been thinking about the centre speaker situation while all this discussion's been going on. I just cant spare the cash now to lash out on a stack of drivers so I'll reconfigure what I've got. Which is a pair of Richter Mentors plus a couple of Jaycar Respionse 8" elacement drivers (sounding a hell of a lot better than the original drivers whose foam surrounds had disintegrated when i bothered to look! The simple project of replacing these drivers got me onto this path—and now I cant get off!
My plan (comments please) is to come up with a set of decent looking speakers for my ht using some Aussie hard wood (maybe veneer). Love the timber grain look.
I'll repair the Richter drivers, replace them in the black (low saf) cabinets, stand them end on end and enclose in timber to make a very solid and fairly low profile long centre speaker out of the two. This will have the desired timber grain blah blah blah (this house has timber everywhere) so cosmetically at least it will be ok. The Richters have one 8" and a tweeter in each and I may replace one of the tweets with a mid.
Then, replicate the Richter boxes in the same timber as the new centre, copy the fairly simple xo units and install the response drivers and similar tweeters. I figure the design is ok and sounds like a silk purse to my sows ear.
Then I think a pair of the fr125s in same timber small rear speakers (or wr125s plus tweets)
I'm confident in my woodworking ability, but will doubtless learn a lot in terms of sound and how to get it.
(Maybe add a sub later in the piece too)
If anyone would like to comment, go for your life (maybe save mine) Questions at the moment are how to wire the joint Richters .
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