G'day
I'm about to start on my first real project, a complete 5.1 channel DIY setup. I've made a few simple bookshelf speakers with pretty crappy drivers but alright results. Also made a few subs mainly using Adire drivers.
Anyway back on topic,
I was thinking of making an MTM center using 2x VIFA P17SJ's and a D27SG, are these OK? I've been told the D25? is good but I have never heard an aluminium tweeter that I liked. Also I read something on here after searching that said MTM as a center is bad? Is this only when the tweeter is placed between the mid's, instead of 2 3rds up from the bottom?
Will these drivers work well for the main's & rears as well? As far as I've been able to find out these are the best drivers I can get without ordering from overseas, they are also on sale this month
I put the specs I could find into WinISD and came up with a 36L ported enclosure @ 44hz with some nice graphs, does this sound about right?
You can probably tell I'm new to this
TIA,
iNeLuKi
I'm about to start on my first real project, a complete 5.1 channel DIY setup. I've made a few simple bookshelf speakers with pretty crappy drivers but alright results. Also made a few subs mainly using Adire drivers.
Anyway back on topic,
I was thinking of making an MTM center using 2x VIFA P17SJ's and a D27SG, are these OK? I've been told the D25? is good but I have never heard an aluminium tweeter that I liked. Also I read something on here after searching that said MTM as a center is bad? Is this only when the tweeter is placed between the mid's, instead of 2 3rds up from the bottom?
Will these drivers work well for the main's & rears as well? As far as I've been able to find out these are the best drivers I can get without ordering from overseas, they are also on sale this month
I put the specs I could find into WinISD and came up with a 36L ported enclosure @ 44hz with some nice graphs, does this sound about right?
You can probably tell I'm new to this
TIA,
iNeLuKi
Wooahh, slow down! Dont all rush to answer you might break something.
Am I right in thinking the problem with MTM centers is due to the seperation of the image when listening from off center, caused by the mid's sound seperation? If so how is a WMTW any better?
Wouldn't a TMMT or TMWMT work better? What about the MTM's in a triangle configuration?
Am I right in thinking the problem with MTM centers is due to the seperation of the image when listening from off center, caused by the mid's sound seperation? If so how is a WMTW any better?
Wouldn't a TMMT or TMWMT work better? What about the MTM's in a triangle configuration?
I had similar concerns about the dispersion of a center MTM speaker. I looked at the MTM-in-a-triangle configuration but decided to drop one of the woofers to make the box smaller. Still plays plenty loud enough!
Pics here:
http://www.apcl43.dsl.pipex.com/center.htm
Nice one,
David.
Pics here:
http://www.apcl43.dsl.pipex.com/center.htm
Nice one,
David.
Hi there,
I designed my own center-speaker as well... If you want to see something of it, go to
Joris' Website , (please don't look at the annoying pop-ups), click on 'Project Page' and if the page has loaded, click on the wire-drawing of the centerspeaker. It will now download a zipfile with the design in PDF-format.
I've written it in Dutch, but if you want to have it in English, maybe I can make an English version (probably a few hours and a few beers further).....
If you want to use Vifa drivers, maybe you can take a look at the next design: Premium 33???
There's a design of a Vifa Premium 22XT, and they have also designed a centerspeaker with the same drivers and components as the 22XT. Guess what, it's called the 22XT Center.
Maybe you can change the design of the 33 a little and build a 33XT Center?
BTW: 33XT uses
regards, Joris
P.S. Premium 22XT is bij Vifa, and the Premium 33 is by ScanSpeak!!!!!
Zipfiles:
Premium 33
Premium 22 XT
Premium 22 XT Center
I designed my own center-speaker as well... If you want to see something of it, go to
Joris' Website , (please don't look at the annoying pop-ups), click on 'Project Page' and if the page has loaded, click on the wire-drawing of the centerspeaker. It will now download a zipfile with the design in PDF-format.
I've written it in Dutch, but if you want to have it in English, maybe I can make an English version (probably a few hours and a few beers further).....
If you want to use Vifa drivers, maybe you can take a look at the next design: Premium 33???
There's a design of a Vifa Premium 22XT, and they have also designed a centerspeaker with the same drivers and components as the 22XT. Guess what, it's called the 22XT Center.
Maybe you can change the design of the 33 a little and build a 33XT Center?
BTW: 33XT uses
regards, Joris
P.S. Premium 22XT is bij Vifa, and the Premium 33 is by ScanSpeak!!!!!
Zipfiles:
Premium 33
Premium 22 XT
Premium 22 XT Center
Thanks for the info guys, much appreciated.
I want the best quality sound I can get from this setup on my budget. I was thinking about making a new HiFi cabinet with an spot underneath the TV for an upright MTM centre, and the AV gear on shelves either side. This way it wouldn't look that weird. Its either that or spend more on the mains so I can just use the "Phantom" centre.
I was told by someone that the promlem with horizontal MTM's is the midrange interaction causing "suckouts", I'm finding it strange that most of these "suckouts" occur at the crossover point. Also why isn't the interaction between the woofers in an WMTW audible? Wouldn't it have the same issues when playing effects and low end stuff? I thought that WMTW's were better because of the increased horizontal dispersion resulting from the vertical array of the mid and tweeter, not because of interaction and "suckouts"
Thanks again.
I want the best quality sound I can get from this setup on my budget. I was thinking about making a new HiFi cabinet with an spot underneath the TV for an upright MTM centre, and the AV gear on shelves either side. This way it wouldn't look that weird. Its either that or spend more on the mains so I can just use the "Phantom" centre.
I was told by someone that the promlem with horizontal MTM's is the midrange interaction causing "suckouts", I'm finding it strange that most of these "suckouts" occur at the crossover point. Also why isn't the interaction between the woofers in an WMTW audible? Wouldn't it have the same issues when playing effects and low end stuff? I thought that WMTW's were better because of the increased horizontal dispersion resulting from the vertical array of the mid and tweeter, not because of interaction and "suckouts"
Thanks again.
i have 4 Vifa TC 11cm midbass drivers and 2 Vifa TC 19mm tweeters.
i want to work this into a center speaker. the limitation is taht teh center speaker mus tbe less than 26" wide and 5.75" high.
3 choices
a) 2 tweeters in verticall array flanked one each side by 2 4" to do this I'd have to modify the plastic flanges of the tweeter, this will do 2 things (1) the 2 tweeters would then fit in 5.75" ht and the center of the tweeters would be 1" closer (pushing comb effcts up a bit). The inner mids would run till teh tweeters XO freq and outer mids could then be used for baffle step compensation.
b) T MMMM T i have heard this is a good config for center speakers. But I dont know what XO to use. I could series/ parallel the 4 mids and use L-R baffle step compensation but I have not been happy with baffle step comp ckts like these in the past. How would one wire this center configuration?
c) MM TT MM all drivers in a horizontal line. here again I woulc use teh inner mids upto the tweeters XO freq. and the outer mids for baffle step comp (BSC).
i also have a few parts. lots of caps 10uf, 6.8uf 4.7uf, a few 10W resistors 4ohms, 5 ohms, 6.8 ohms, 10 ohms and a few inductors ready. 1.8mh (I can upgrade this to 3mh by instering a iron core), 0.25mh (again I can upgrade these to 0.45mh using a ferrite bobbin i found, and 0.45mh that cannot be changed.
all help is required. i am here for only a few days and would like to get this done over this weekend. Think of it as "McGyver" building a speaker. Did any of you guys ever see this series?
i want to work this into a center speaker. the limitation is taht teh center speaker mus tbe less than 26" wide and 5.75" high.
3 choices
a) 2 tweeters in verticall array flanked one each side by 2 4" to do this I'd have to modify the plastic flanges of the tweeter, this will do 2 things (1) the 2 tweeters would then fit in 5.75" ht and the center of the tweeters would be 1" closer (pushing comb effcts up a bit). The inner mids would run till teh tweeters XO freq and outer mids could then be used for baffle step compensation.
b) T MMMM T i have heard this is a good config for center speakers. But I dont know what XO to use. I could series/ parallel the 4 mids and use L-R baffle step compensation but I have not been happy with baffle step comp ckts like these in the past. How would one wire this center configuration?
c) MM TT MM all drivers in a horizontal line. here again I woulc use teh inner mids upto the tweeters XO freq. and the outer mids for baffle step comp (BSC).
i also have a few parts. lots of caps 10uf, 6.8uf 4.7uf, a few 10W resistors 4ohms, 5 ohms, 6.8 ohms, 10 ohms and a few inductors ready. 1.8mh (I can upgrade this to 3mh by instering a iron core), 0.25mh (again I can upgrade these to 0.45mh using a ferrite bobbin i found, and 0.45mh that cannot be changed.
all help is required. i am here for only a few days and would like to get this done over this weekend. Think of it as "McGyver" building a speaker. Did any of you guys ever see this series?
ok here i am working in left field without a soruce of new caps or resistors (except what i got in hand) or a lathe or good enamelled wire to make some new inductors. fortunately i managed to borrow a decent bridge.
i converted an air core 1.8mh (R=0.6ohms) into a 3.5mh inductor by inserting a 40mm dia x 40mm tall iron core (soft) in the gap.
then i paralleled a bunch of 10uf caps (7 to be exact) to make a big 78uf cap.
now i have 2 options.
a) shave of teh tweeter flanges so that 2 of them fit in 5.75" verticaly arrray then go MM TT MM or go for a horizontal array of MMTTMM.
the XO for this would be 2.5 way:
a) the big inductor 3.5mH for the 2 outer M's (this will be baffle step comp. 2 M's in series.
b) 0.45mh (air core) and a RC using 10ohms and 78uf for the inner M's again in series
c) 3 ohms level matching resistor followed by a 5uf cap and 0.45mh (ferrite core) inductor for tthe 2 tweeters in parallel
alternate 2:
do not modify the tweeter and go T MMMM T.
The XO for this would be:
a) a LR BSC ckt using a 1.8mh inductor (no iron core) and a 4 ohm resistor followed by 0.45mh (air core) and a RC using 10uf and 4ohms for the 4 M's in series parallel
b) level mathcing 3.3 ohm resistor followed by 2.2 uf cap and 0.45mh (ferrite core) inductor.
I would love opinions so I dont need to cut 3 bafflles. The XO parts are ready.
I have exactly 3 hours on saturday to make the center speaker.
i converted an air core 1.8mh (R=0.6ohms) into a 3.5mh inductor by inserting a 40mm dia x 40mm tall iron core (soft) in the gap.
then i paralleled a bunch of 10uf caps (7 to be exact) to make a big 78uf cap.
now i have 2 options.
a) shave of teh tweeter flanges so that 2 of them fit in 5.75" verticaly arrray then go MM TT MM or go for a horizontal array of MMTTMM.
the XO for this would be 2.5 way:
a) the big inductor 3.5mH for the 2 outer M's (this will be baffle step comp. 2 M's in series.
b) 0.45mh (air core) and a RC using 10ohms and 78uf for the inner M's again in series
c) 3 ohms level matching resistor followed by a 5uf cap and 0.45mh (ferrite core) inductor for tthe 2 tweeters in parallel
alternate 2:
do not modify the tweeter and go T MMMM T.
The XO for this would be:
a) a LR BSC ckt using a 1.8mh inductor (no iron core) and a 4 ohm resistor followed by 0.45mh (air core) and a RC using 10uf and 4ohms for the 4 M's in series parallel
b) level mathcing 3.3 ohm resistor followed by 2.2 uf cap and 0.45mh (ferrite core) inductor.
I would love opinions so I dont need to cut 3 bafflles. The XO parts are ready.
I have exactly 3 hours on saturday to make the center speaker.
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