There is another 8" MTM out there using the Dayton 8" woofers and 8" Dayton dome tweeter. Its real emphasis is on cranking up and being a speaker that won't lose control of its BMs at high volumes. It uses the Dayton tweeter that has a low Fs so that it can move most of the midrange output our of the woofers, allowing the midrange to stay cleaner at high volumes. I wonder what happens to the midrange on the Kit281s when those woofers get hopping, as the AV8s are not XBL^2 woofers.
Err, what I'm trying to say is: the Kit281s will go real loud with an 80 watt amplifier (I had one). In fact, they won't go much louder with a 400 watt amp. But I think the bass impact and dynamics are better with the more powerful amplifier. A stereo amp is probably a better choice than a receiver.
They're not XBL2 woofers but neither is anything else! The displacement is decent at 5.5 mm, so they can handle a heck of a lot of midbass. The low bass is a little subdued compared to a subwoofer. I don't think the midrange distorting with more output is a real concern since a steep crossover is used. It shouldn't distort more than any other good 8" midwoofers.
They're not XBL2 woofers but neither is anything else! The displacement is decent at 5.5 mm, so they can handle a heck of a lot of midbass. The low bass is a little subdued compared to a subwoofer. I don't think the midrange distorting with more output is a real concern since a steep crossover is used. It shouldn't distort more than any other good 8" midwoofers.
Navin > the TC line looks quite good value, the 6.5s do have a bit of breakup around 2.5k which will give quite a forward sound - this might well be to his taste as by the sounds of it loud is what he's after.
Using two of them is a good idea, but MTMs can be tricky & will require a lower than usual xover freq. hence going for a low fs tweeter. I wouldnt recommend a 2.5way due to added complexity, (It can be really hard to balance bass & mid level).
Using two of them is a good idea, but MTMs can be tricky & will require a lower than usual xover freq. hence going for a low fs tweeter. I wouldnt recommend a 2.5way due to added complexity, (It can be really hard to balance bass & mid level).
WOW!
I'm really impressed with all this help I'm getting from this forum!
I went away for a two days vacation and when I came back, it took me several hours to analyze all those answers! Thanks to everyone that replied!
I'm not in a hurry to finish those speakers, I'm the type that enjoys the listening as much as the building process, so a kit is so-so for me.
For those that suggested the Adire kit 281, thanks but they have a basic flaw, I would not be able to write my name on these as they were designed by someone else. Bummer! I know.
I looked at the Vifa TC line and must admit that they are fairly impressive for the sensible price they go for. The Vifa TC18WG-15-08 7" Woofer is a really good deal, and at 9$ I could afford to pack 3 or 4 per box, giving a really good sensitivity, good frequency responce and an excelent f3 of 32Hz in a vented 4.5ft^3 box. (The only drawback is that the 9$ special ends tomorrow, so it will depends on how fast I decide to act).
In my junk box I found two Pioneer tweeters (FBDD69-51F) perhaps those could do the job with the Vifa woofers and make me the best/cheapest speakers around the block? If not, I could probably go for a tweeter similar to the one on the Adire 281.
I guess a good cross over point would be around 2.5kHz, this way it would be easy to find a tweeter and the woofer would be freed from much of the higher frequency?
I should also mention that I just finished renovating the kitchen and I over ordered some stuff. I already have a lot of ¾" MDF and quite enough veneered oak to do both box, so the cabinets will be "free" as in not to be included within the budget. Still I maintain that 350$ would be a good max point, but lower would be nice
I'll now be waiting impatiently for you guy's advice.
Thanks again,
Sébastien
I'm really impressed with all this help I'm getting from this forum!
I went away for a two days vacation and when I came back, it took me several hours to analyze all those answers! Thanks to everyone that replied!
I'm not in a hurry to finish those speakers, I'm the type that enjoys the listening as much as the building process, so a kit is so-so for me.
For those that suggested the Adire kit 281, thanks but they have a basic flaw, I would not be able to write my name on these as they were designed by someone else. Bummer! I know.
I looked at the Vifa TC line and must admit that they are fairly impressive for the sensible price they go for. The Vifa TC18WG-15-08 7" Woofer is a really good deal, and at 9$ I could afford to pack 3 or 4 per box, giving a really good sensitivity, good frequency responce and an excelent f3 of 32Hz in a vented 4.5ft^3 box. (The only drawback is that the 9$ special ends tomorrow, so it will depends on how fast I decide to act).
In my junk box I found two Pioneer tweeters (FBDD69-51F) perhaps those could do the job with the Vifa woofers and make me the best/cheapest speakers around the block? If not, I could probably go for a tweeter similar to the one on the Adire 281.
I guess a good cross over point would be around 2.5kHz, this way it would be easy to find a tweeter and the woofer would be freed from much of the higher frequency?
I should also mention that I just finished renovating the kitchen and I over ordered some stuff. I already have a lot of ¾" MDF and quite enough veneered oak to do both box, so the cabinets will be "free" as in not to be included within the budget. Still I maintain that 350$ would be a good max point, but lower would be nice
I'll now be waiting impatiently for you guy's advice.
Thanks again,
Sébastien
Re: WOW!
I have used this combination though not as push push. i managed to balance the level quite easily all you have to do is play with the XO of the second 18cm woofer.
the reason i like 2.5 is that i find large inductors (usually mandated by BSC) damp the midrnage clarity and I mean large air core stuff using 14AWG wire and having DCR less than .2 ohms. with a 2.5 wya the large inductor is only affecting one woofer that is not doing much in the midrange anyway. Tony Gee had similar findings. See his report on the Progress. my tests were done using 2x SS8546 (with a 9900).
I have used the TC18cm to 2k in a series XO about 9db/oct with no audible problems. granted it is not a party woofer. so dont use it if you want a woofer that can handle abuse. It will play Jazz to realsitic levels though.
I did not know they were that cheap. I paid US$15 for each that includes shipping and duty et al. and i live in India.
well if you want to go for a multi driver tower please note the following....
1. each TC18 requires 20 liters to breathe so if you want to use 3 per box your box should be 60 ltiers + which is quite possible. internal dimensions of 36" x 8" x 14" (HWD) should do it.
2. if I were using 3 woofers i would use 1 TC 18 with a TC series tweeter (they are very well mathced) as a 2 way. then series the other 2 woofers and use them with a large inductor to compensate for baffle step. t make things realy interesting I would mounth these 2 woofers on the rear of the box with the upper one in push push with the midbass.
3. if you are adventurous I would even mix the alignments of the 2 18cm woofers. using bass reflex alignment for theone that is not in push push with the midbass in the front (the lower of the 2 woofers). the bassfelxx alignement requires more volume than 20 liters but adds a bit more punch to the sound.
confused i know i am.....
ok...lets say you have 3 woofers and 1 tweeter. better than buying 4 woofers and using that pioneer.
take one woofer aside of teh 3 and designate that as the midbass. the other 2 will be used as woofers. build a "standard" 2way using the midbass and tweeter and use the woofers for BSC. simpler?
Ap said:
I have used this combination though not as push push. i managed to balance the level quite easily all you have to do is play with the XO of the second 18cm woofer.
the reason i like 2.5 is that i find large inductors (usually mandated by BSC) damp the midrnage clarity and I mean large air core stuff using 14AWG wire and having DCR less than .2 ohms. with a 2.5 wya the large inductor is only affecting one woofer that is not doing much in the midrange anyway. Tony Gee had similar findings. See his report on the Progress. my tests were done using 2x SS8546 (with a 9900).
I have used the TC18cm to 2k in a series XO about 9db/oct with no audible problems. granted it is not a party woofer. so dont use it if you want a woofer that can handle abuse. It will play Jazz to realsitic levels though.
tool49 said:
I did not know they were that cheap. I paid US$15 for each that includes shipping and duty et al. and i live in India.
well if you want to go for a multi driver tower please note the following....
1. each TC18 requires 20 liters to breathe so if you want to use 3 per box your box should be 60 ltiers + which is quite possible. internal dimensions of 36" x 8" x 14" (HWD) should do it.
2. if I were using 3 woofers i would use 1 TC 18 with a TC series tweeter (they are very well mathced) as a 2 way. then series the other 2 woofers and use them with a large inductor to compensate for baffle step. t make things realy interesting I would mounth these 2 woofers on the rear of the box with the upper one in push push with the midbass.
3. if you are adventurous I would even mix the alignments of the 2 18cm woofers. using bass reflex alignment for theone that is not in push push with the midbass in the front (the lower of the 2 woofers). the bassfelxx alignement requires more volume than 20 liters but adds a bit more punch to the sound.
confused
i know i am.....ok...lets say you have 3 woofers and 1 tweeter. better than buying 4 woofers and using that pioneer.
take one woofer aside of teh 3 and designate that as the midbass. the other 2 will be used as woofers. build a "standard" 2way using the midbass and tweeter and use the woofers for BSC. simpler?
Of course there will be pics! Just ordered 6 TC18 with two matching TC26 tweeter.
I'm really interested with your idea of using too woofers for the BSC and 1 woofer/tweeter in a simple two way design. I must admit that I'm not shure about what type of crossover that will require, but i'm sure that over time I'll get around to it.
Thanks!
Sébastien
I'm really interested with your idea of using too woofers for the BSC and 1 woofer/tweeter in a simple two way design. I must admit that I'm not shure about what type of crossover that will require, but i'm sure that over time I'll get around to it.
Thanks!
Sébastien
you are a brave man....you are now following a person who has not read a book on speaker design (not even the famed cookbook by dickason or the bible by weems)
seriously...I have used the TC series in 3 pairs of speakers. MMTMM center channel using 4" and 3/4", 2.5 way main speakers using 6.5" and 1" as well as TC SG type in a 6" 2 way for my father in law (he wanted stereo speaker he could keep next to his 34" TV). They are good value for money.
What I like about these drivers is that the roll of is not too difficult and work fine with simple XOs and series XOs. Also what i found is that the enviroment (location of speaker in room) can be compensated for by twiggling XO values. Here Series XOs are easierto play with. It is inherent in their design. Andy G is a guru on these XOs.
the push push idea ia dave (planet 10).
lets start from teh top of the speaker.....
you can decide if you want a tweeter on top or tweeter below midbass. that and your listening height will determine your speaker height. ideally your listening height (ear or eye level) should be centered with the midbass. I like this best.
once you have done that you place 1 woofer directly behind the midbass in a sealed cabinet that is shared by both. below the first woofer you put the second woofer in a seperate bass reflex cabinet. you can use boxplot 3.0 to calculate teh cabinet size.
my guess is that you will need about 40 ltiers for the midbass+woofer sealed box and 30 liters for the bass reflex woofer.
the XO is rather simple. are you looking at series XOs? if so I can send you what i have done here. if not LspCad can help you make a XO too.
seriously...I have used the TC series in 3 pairs of speakers. MMTMM center channel using 4" and 3/4", 2.5 way main speakers using 6.5" and 1" as well as TC SG type in a 6" 2 way for my father in law (he wanted stereo speaker he could keep next to his 34" TV). They are good value for money.
What I like about these drivers is that the roll of is not too difficult and work fine with simple XOs and series XOs. Also what i found is that the enviroment (location of speaker in room) can be compensated for by twiggling XO values. Here Series XOs are easierto play with. It is inherent in their design. Andy G is a guru on these XOs.
the push push idea ia dave (planet 10).
lets start from teh top of the speaker.....
you can decide if you want a tweeter on top or tweeter below midbass. that and your listening height will determine your speaker height. ideally your listening height (ear or eye level) should be centered with the midbass. I like this best.
once you have done that you place 1 woofer directly behind the midbass in a sealed cabinet that is shared by both. below the first woofer you put the second woofer in a seperate bass reflex cabinet. you can use boxplot 3.0 to calculate teh cabinet size.
my guess is that you will need about 40 ltiers for the midbass+woofer sealed box and 30 liters for the bass reflex woofer.
the XO is rather simple. are you looking at series XOs? if so I can send you what i have done here. if not LspCad can help you make a XO too.
I'm not that brave, but I figured that these are rather versatile speakers, so if I don't like the first box, nothing prevents me from reverting to a simple 2 way design with a sub. And then I would even have enough to build two rear channels and a center channel converting the whole lot in a cheap surround sound system.
I measured my listening height and it oscillates between 38" and 43" depending on the sofa/chair I'm sitting in. I guess that means that the tweeter should go on top of the mid.
In the push-push configuration, I'm not sure that I understand every factor at stakes here. Won't that throw the mids 3db under the sensitivity of the other drivers (bass and tweeter)?
These drivers beeing inefficient 86db, and the tweeter beeing 92 db, shouldn't I try to add them up instead of substrating them in a push-push?
Attached is a quick drawing I made of what I understood of your idea.
And I would like to know what the crossovers would look like of course. Especially with that cross betwee sealed and ported enclosures.
Thanks,
Sébastien
I measured my listening height and it oscillates between 38" and 43" depending on the sofa/chair I'm sitting in. I guess that means that the tweeter should go on top of the mid.
In the push-push configuration, I'm not sure that I understand every factor at stakes here. Won't that throw the mids 3db under the sensitivity of the other drivers (bass and tweeter)?
These drivers beeing inefficient 86db, and the tweeter beeing 92 db, shouldn't I try to add them up instead of substrating them in a push-push?Attached is a quick drawing I made of what I understood of your idea.
And I would like to know what the crossovers would look like of course. Especially with that cross betwee sealed and ported enclosures.
Thanks,
Sébastien
Attachments
Re: WOW!
I am just finishing a box using these TC drivers that Vifa made for Infinity. It is a big ported MTM bass reflex enclosure. I modeled the box volume in BoxPlot 3.0 and got 4.5 ft^3 volume with 2 3" diameter 6.85" long ports. The tweeter I am using is the Dayton PT2 planar tweeter with a 3rd order HP filter crossed over at 2.5 KHz. I was able to get a very smooth HF response, but am having a little trouble getting the response smooth at the x-over point. One thing that amazed me with these Vifa TC woofers was that I am able to get an f3 of roughly 32 Hz in this box. (I'm working off memory here) Also, at $9.00 a woofer, why not just order a few and play around with them? They sound pretty good, and you're not out a lot of money if you don't like them.
Cheers,
Zach
tool49 said:
I am just finishing a box using these TC drivers that Vifa made for Infinity. It is a big ported MTM bass reflex enclosure. I modeled the box volume in BoxPlot 3.0 and got 4.5 ft^3 volume with 2 3" diameter 6.85" long ports. The tweeter I am using is the Dayton PT2 planar tweeter with a 3rd order HP filter crossed over at 2.5 KHz. I was able to get a very smooth HF response, but am having a little trouble getting the response smooth at the x-over point. One thing that amazed me with these Vifa TC woofers was that I am able to get an f3 of roughly 32 Hz in this box. (I'm working off memory here) Also, at $9.00 a woofer, why not just order a few and play around with them? They sound pretty good, and you're not out a lot of money if you don't like them.
Cheers,
Zach
tool49 said:
your drawing is very nice. I mae a similar one using MS word's drawing tools but did not know how to attach it. i could fax it to you if you like.
anyway what i was thinking of is having both the woofers Sealed as well as bass reflex fire rear wards. also you would need a method of attaching the magnets of the midbass to the sealed woofer to get all the benefit of push push. email dave planet 10 here he is is the resident expert on push push. he can tell you if there will be any loss in sensitivity.
the XO is quite simple. my XO is a lot simpler as I have only 2 vifa 18cm drivers not 3 as you are using also the inductor value for the lower driver will be much larger if you are putting the 2 woofers in series. (I would think it would be double).
the tweeter is 92db. the midbass is 86db. so you will have to pad the tweeter 4-6db or so. the 86db they spec is wihtout BSC with BSC it drops further.
i can draw my XO and fax that yuo too. it is series XO with a 1 mh inductor for the second driver.
Humm what is a Fax? Just kidding, but I don't have any equipment of the sort. Perhaps you should just zip the word document to be able to attach it in a message. Or else, you could always e-mail it to me.
Well Dave (Planet 10), if your listening (or watching), what would be your take on this?
Well then, I purchased some extra woofers (just in case) so I might go up to four in the same enclosure. Thus making it possible to reach around 90db of sensitivity. This would then prevent the need for any padding around the tweeter.
I tried all day to model this type of enclosure but to no avail... Every piece of software that I tried ended up useless as soon as I tried to get some push-push configuration. Does anybody have an idea about how I should model this to get a proper enclosure size?
Thanks!
Sébastien
Well Dave (Planet 10), if your listening (or watching), what would be your take on this?
Well then, I purchased some extra woofers (just in case) so I might go up to four in the same enclosure. Thus making it possible to reach around 90db of sensitivity. This would then prevent the need for any padding around the tweeter.
I tried all day to model this type of enclosure but to no avail... Every piece of software that I tried ended up useless as soon as I tried to get some push-push configuration. Does anybody have an idea about how I should model this to get a proper enclosure size?
Thanks!
Sébastien
ooops....
it is very difficult to do what you are doing if it possible at all keeping impedance above 4 ohms.....
you can do this if you drop impedace to 2 ohms but then your amp better be a brute or you migth have to be active for the woofers.
given BSC and an above 4 ohms impedance the woofer sens (in this case 86db) will be your best bet
it is very difficult to do what you are doing if it possible at all keeping impedance above 4 ohms.....
you can do this if you drop impedace to 2 ohms but then your amp better be a brute or you migth have to be active for the woofers.
given BSC and an above 4 ohms impedance the woofer sens (in this case 86db) will be your best bet
Humm, active is not really an option in my case. And if at all possible, the impedance should be 8 ohm, 4 ohm would be ok, but my amp would probably overheat.
Now if I go for a simple solution like one two way speaker sealed (mid + tweeter) and a dual vented sub would it be easier to keep the impedence higher? (perhaps I'm not fully understanding the rules here, but if the tweeter and the mid are in series via the crossover and that the two woofers are also in series, if both "enclosures" are in parallel, this would give something close to 8ohms right? (bear in mind that this is my first loudspeaker project aside from several subwoofers....) Another possible solution would be to use simple parallel crossovers in both cases and to put both enclosures in series. This would make it easy to bi-amp those loudspeakers and would provide two 4 ohm speakers which would be ok with the gainclones. (not my HT receiver tho)
I'm just throwing ideas here. If I'm wrong (which is most probably the case) please correct me!
Thanks,
Sébastien
Now if I go for a simple solution like one two way speaker sealed (mid + tweeter) and a dual vented sub would it be easier to keep the impedence higher? (perhaps I'm not fully understanding the rules here, but if the tweeter and the mid are in series via the crossover and that the two woofers are also in series, if both "enclosures" are in parallel, this would give something close to 8ohms right? (bear in mind that this is my first loudspeaker project aside from several subwoofers....) Another possible solution would be to use simple parallel crossovers in both cases and to put both enclosures in series. This would make it easy to bi-amp those loudspeakers and would provide two 4 ohm speakers which would be ok with the gainclones. (not my HT receiver tho)
I'm just throwing ideas here. If I'm wrong (which is most probably the case) please correct me!
Thanks,
Sébastien
boy you are going all ove the place.
i made a series Xo for the midbass and tweeter.
then connect teh woofers in series (nominal impeance 16 ohms) and connct thi combination in parallel with the above series XO 2 way.
Look at Andy G's site on series XOs.
your impedance using this config will vary depending on freq droping as low as 4 ohms and going as high as 10 ohms and will have a few narrow impedance peaks.
if you connect all 3 vifa divers (2 woofers and 1 midbass) in parallelyour impedance will drop as low as 2 ohms and that can cause some amps to misbehave.
i made a series Xo for the midbass and tweeter.
then connect teh woofers in series (nominal impeance 16 ohms) and connct thi combination in parallel with the above series XO 2 way.
Look at Andy G's site on series XOs.
your impedance using this config will vary depending on freq droping as low as 4 ohms and going as high as 10 ohms and will have a few narrow impedance peaks.
if you connect all 3 vifa divers (2 woofers and 1 midbass) in parallelyour impedance will drop as low as 2 ohms and that can cause some amps to misbehave.
I'll clarify if I can.
series & parallel xovers do not greatly affect the overall sytem impedance - they are just different ways of wiring the xover components.
Youve got to remember that a xover breaks up the bands for the various drivers.
So an 8ohm tweeter and an 8ohm woofer results in a system nominal 8ohm load - I say nominal because it varies from 20hz-20khz - check out some of the mesurements in reviews on stereo-phile to see what I mean.
Now as for configurations I would go simple as possible, I would nt attempt a 3way without measruing equipment. (So ignore my last picture).
I would go for a 2way MTM, bass reflex for efficiency - as the drivers are only 86db you can get up to 92db by parralleling the bass drivers ith a usable midband of around 88-90 - means it's easy to match the tweeter.
I wouldnt series bass drivers - from my experience it just doesnt sound right, partly due to the huge increase of impedance at resonance (peak in the range of 60ohms), also the inductor size has to double (so cost & losses increase).
series & parallel xovers do not greatly affect the overall sytem impedance - they are just different ways of wiring the xover components.
Youve got to remember that a xover breaks up the bands for the various drivers.
So an 8ohm tweeter and an 8ohm woofer results in a system nominal 8ohm load - I say nominal because it varies from 20hz-20khz - check out some of the mesurements in reviews on stereo-phile to see what I mean.
Now as for configurations I would go simple as possible, I would nt attempt a 3way without measruing equipment. (So ignore my last picture).
I would go for a 2way MTM, bass reflex for efficiency - as the drivers are only 86db you can get up to 92db by parralleling the bass drivers ith a usable midband of around 88-90 - means it's easy to match the tweeter.
I wouldnt series bass drivers - from my experience it just doesnt sound right, partly due to the huge increase of impedance at resonance (peak in the range of 60ohms), also the inductor size has to double (so cost & losses increase).
Attachments
Re: Re: WOW!
OK,
I got my towers with the Infinty/Vifa TC woofers up and running last night. The box is 130 Liters, with two 3" diameter ports that are 5.8" long. Let me tell you.........This thing has BASS!!!!!!!!!! I put on Dark Side Of The Moon, and my whole apartment shook! Keep in mind that these are just being powered by my Pioneer home theater receiver. The boxes wound up being VERY large, but it was worth it! I'm still mesing around with the x-over, but for now I just have a basic 1st order x-over to help protect the planar tweeter. If you want me to send you some box plots that I worked out, let me know. I hope this helps.
Cheers,
Zach
usekgb said:
OK,
I got my towers with the Infinty/Vifa TC woofers up and running last night. The box is 130 Liters, with two 3" diameter ports that are 5.8" long. Let me tell you.........This thing has BASS!!!!!!!!!! I put on Dark Side Of The Moon, and my whole apartment shook! Keep in mind that these are just being powered by my Pioneer home theater receiver. The boxes wound up being VERY large, but it was worth it! I'm still mesing around with the x-over, but for now I just have a basic 1st order x-over to help protect the planar tweeter. If you want me to send you some box plots that I worked out, let me know. I hope this helps.
Cheers,
Zach
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