thinking of putting a couple in some T-Lines
the initial sims seem to be pretty good (F3 at about 35Hz i think only my electric just went out so i've got to start a fresh 🙄 )
before i do and more importantly before i spend any money on a pair has anyone got any thoughts?
dave
the initial sims seem to be pretty good (F3 at about 35Hz i think only my electric just went out so i've got to start a fresh 🙄 )
before i do and more importantly before i spend any money on a pair has anyone got any thoughts?
dave
Tony Gee put one in a ported box and seems to think pretty highly of the result.
http://home.hetnet.nl/~geenius/USB.html
I don't know if that's of any help, but it's nice to know a respected designer has used them successfully. And there are lots of measurements and a complete crossover that may be helpful.
http://home.hetnet.nl/~geenius/USB.html
I don't know if that's of any help, but it's nice to know a respected designer has used them successfully. And there are lots of measurements and a complete crossover that may be helpful.
I'm very tempted to try one of these coaxials, too, but I would use it in a true 3-way. Because of the coaxial tweeter position I would expect that there will be much IM distortion with big woofer movement - i.e. if to try to produce real bass. I suppose this is the reason why most people who tried them weren't too satisfied.
Hertzschmerz said:
You know, I was just thinking that a Seas coax combined with one or two Adire Extremis 6's would be a killer compact and shielded monitor for audio or HT, and not much (if at all) more expensive than many of the boring and sterile Seas Excel or ScanSpeak 7" 2-ways that seem to be cropping up like high priced locusts. With a T18/Extremis combination, you'd get the coherency of a dual-concentric from the Seas and the Extremis would be there to keep the Seas woofer from moving too much while providing a solid bridge between mains and sub.
It's not something I'll probably ever do, at least not at this point, because I'm more into bigger dual concentrics. But for someone who needs a smaller/thinner speaker and still craves some measure of coherency, it could work out very well.
Hertzschmerz said:
How so? Is this different than a regular two-way? IM is usually a concern when the high frequency radiator is subject to woofer cone's motion, a common complaint against full range drivers. If I'm not mistaken this Seas tweeter is fixed.
For what it's worth, here's a design for the T18RE/XTVFC by one of the engineers at Seas:
http://www.madisound.com/Seas H1144 Box and Xover.pdf
http://www.madisound.com/Seas H1144 Box and Xover.pdf
thanks for the responses
these will be used as DJ monitors built into the deck stand i'm going to build
they'll end up being about a meter or so away from my head and placed against a wall in a small room (9' x 11')
because they'll be nearfield i need a point source design and did think about a full range driver but for the music i play it would be a tough job for a single driver to cope with both lows and highs
i was looking originally at the beyma 8BX but whilst i'll have no trouble with any length of line (they'll become the legs of the stand) the 8" diameter means the cross-section may cause problems
the other problem with the 8BX is the Fs being 52Hz whilst room lift is going to help the overall response it wont naturally play down as low as i need
does anyone have any thoughts about another driver that might be suitable?
the music i play has a lot of content around 30-45Hz but i don't want a sub and satelite design as i need to be able to hear the bass first hand not filtered up to ear level when standing
cheers
dave
these will be used as DJ monitors built into the deck stand i'm going to build
they'll end up being about a meter or so away from my head and placed against a wall in a small room (9' x 11')
because they'll be nearfield i need a point source design and did think about a full range driver but for the music i play it would be a tough job for a single driver to cope with both lows and highs
i was looking originally at the beyma 8BX but whilst i'll have no trouble with any length of line (they'll become the legs of the stand) the 8" diameter means the cross-section may cause problems
the other problem with the 8BX is the Fs being 52Hz whilst room lift is going to help the overall response it wont naturally play down as low as i need
does anyone have any thoughts about another driver that might be suitable?
the music i play has a lot of content around 30-45Hz but i don't want a sub and satelite design as i need to be able to hear the bass first hand not filtered up to ear level when standing
cheers
dave
rdf said:
Good question. Yes this tweeter is fixed. I see it this way: The woofer cone in this design acts as a kind of waveguide for the tweeter. The listener in front of the loudspeaker hears the sound of the waveguide rather than the sound of the tweeter itself. Now this waveguide is not static but moving...
If I understood correctly, this is the reason why the studio monitor manufacturer ME Geithain put the tweeter in the Nearfield models on a plate in front of their woofers which covers most of the woofer cone.
An externally hosted image should be here but it was not working when we last tested it.
Almost all of Tannoy's coaxial drivers use the woofer as the waveguide, I think.Hertzschmerz said:
Hi Synergy,
I'm interested in using the T18-coax myself, and I want to share an idea with you: if you need the monitors to produce good bass and a perfect sound stage from nearby, wouldn't this be a good opportunity to build a real d'Appolito-system? I mean, most so-called d'Appolito systems don't really apply to the rule that Joe d'Appolito stated: the heart-to-heart distance between the two woofers in a W-T-W system being less than 2/3 of the wavelength of the cross-over frequency.
Now, if you would build a three-way system that uses two 18-cm woofers and the T18-coax in the middle and use a bass-to-mid crossover frequency of, say, 250 Hz, you'll get the best of both worlds:
1. A perfect d'Applito configuration
2. Great sound stage and stereo image
3. The woofer-unit of the T18 is freed from its lower range and it doesn't make large movements anymore --> so: better bass reproduction and less IM
4. and ... 😎 ...it may look great too (having three identically looking units in a row)!
You will just have to find a 18cm unit that has about the same sensitivity (88 dB ?) and that has a suitable Vas, but that can not really be a problem.
And, ofcourse, after you built it, please tell me how you like it, because I would want to build a system like this, but don't have the money (yet !) ;-)
Any reactions?
I'm interested in using the T18-coax myself, and I want to share an idea with you: if you need the monitors to produce good bass and a perfect sound stage from nearby, wouldn't this be a good opportunity to build a real d'Appolito-system? I mean, most so-called d'Appolito systems don't really apply to the rule that Joe d'Appolito stated: the heart-to-heart distance between the two woofers in a W-T-W system being less than 2/3 of the wavelength of the cross-over frequency.
Now, if you would build a three-way system that uses two 18-cm woofers and the T18-coax in the middle and use a bass-to-mid crossover frequency of, say, 250 Hz, you'll get the best of both worlds:
1. A perfect d'Applito configuration
2. Great sound stage and stereo image
3. The woofer-unit of the T18 is freed from its lower range and it doesn't make large movements anymore --> so: better bass reproduction and less IM
4. and ... 😎 ...it may look great too (having three identically looking units in a row)!
You will just have to find a 18cm unit that has about the same sensitivity (88 dB ?) and that has a suitable Vas, but that can not really be a problem.
And, ofcourse, after you built it, please tell me how you like it, because I would want to build a system like this, but don't have the money (yet !) ;-)
Any reactions?
wieri347 said:
If I understood you right, you wanted to use the T18 in the middle of two woofers?
If so, you'd need to find a woofer with sensitivity well below 88dB. When the two woofer are connected in parallell, the sensitivity will be 88 +6dB, in other words you'd need to find woofers with sensitivity about 82dB. This would give you about 88 dB overall.
regards
seas free download horn
Hello,
if you use a basshorn there is no problem
with the Qts, stroke and bass,
The seas is a cheap solutions for the
Basstuba basshorn
http://www.hm-moreart.de/82.htm
hm-moreart
Hello,
if you use a basshorn there is no problem
with the Qts, stroke and bass,
The seas is a cheap solutions for the
Basstuba basshorn
http://www.hm-moreart.de/82.htm
hm-moreart
seas T18 crossover
There was a posting for a link to a crossover for the Seas T18RE...but the link did not seem to connect for me.
Does anyone have plans for a crossover for this unit? Would a 6db/octave crossover work? (I guess it would need to be at a higher crossover point. I have always liked overall image that 6db/octave crossovers exhibit....and wonder if it would work in this application?
There was a posting for a link to a crossover for the Seas T18RE...but the link did not seem to connect for me.
Does anyone have plans for a crossover for this unit? Would a 6db/octave crossover work? (I guess it would need to be at a higher crossover point. I have always liked overall image that 6db/octave crossovers exhibit....and wonder if it would work in this application?
Hi Bob,
in the past year I have built 3 boxes with this unit (Left, Center, Right) and I am very very pleased with them. They sound beautifully, with a perfect sound-stage. I don't need an extra woofer, but then again I don't play my music very loud.
I have tried two different crossovers. And I must say that I did not hear any difference. One of them uses 12 dB in the tweeter-branch, the other uses a 6 dB filter for the tweeter. Both use 6 dB for the woofer. Since the XP membrane has very little resonance, a 6 dB filter is perfectly suitable.
I can't find the scheme for the 6 dB variant right now, but I can give you the crossover scheme for the other one.
As I said before, the woofer uses a 6 dB filter consisting of a 0,68 mH coil, which of course only works properly if you flatten the impedance curve using a series circuit of 0,82 uF / 10 Ohm in parallel to the woofer.
The tweeter branch uses 0,27 mH and 3,3 uF to create a 12 dB filter. I found the tweeter played a little too loud and used 2,7 uF in combination with 1,8 Ohm to reduce the tweeter volume a little.
The crossover frequency is exactly 3 KHz.
The other crossover I have tried differs in the tweeter branch. As I said, I lost the schema, but I recall it using a 4,7 uH capacitor. But that is not enough, because if you do so the tweeter gets too much energy in the range of its resonance frequency. Therefore, you need an extra LC-circuit tuned to the resonance frequency of the tweeter (1200 Hz). Please note: both crossovers use the tweeter with reversed polarity.
The 12 dB crossover is published in the february-2006 edition of the German magazine Klang Und Ton.
Good Luck !
Ron
in the past year I have built 3 boxes with this unit (Left, Center, Right) and I am very very pleased with them. They sound beautifully, with a perfect sound-stage. I don't need an extra woofer, but then again I don't play my music very loud.
I have tried two different crossovers. And I must say that I did not hear any difference. One of them uses 12 dB in the tweeter-branch, the other uses a 6 dB filter for the tweeter. Both use 6 dB for the woofer. Since the XP membrane has very little resonance, a 6 dB filter is perfectly suitable.
I can't find the scheme for the 6 dB variant right now, but I can give you the crossover scheme for the other one.
As I said before, the woofer uses a 6 dB filter consisting of a 0,68 mH coil, which of course only works properly if you flatten the impedance curve using a series circuit of 0,82 uF / 10 Ohm in parallel to the woofer.
The tweeter branch uses 0,27 mH and 3,3 uF to create a 12 dB filter. I found the tweeter played a little too loud and used 2,7 uF in combination with 1,8 Ohm to reduce the tweeter volume a little.
The crossover frequency is exactly 3 KHz.
The other crossover I have tried differs in the tweeter branch. As I said, I lost the schema, but I recall it using a 4,7 uH capacitor. But that is not enough, because if you do so the tweeter gets too much energy in the range of its resonance frequency. Therefore, you need an extra LC-circuit tuned to the resonance frequency of the tweeter (1200 Hz). Please note: both crossovers use the tweeter with reversed polarity.
The 12 dB crossover is published in the february-2006 edition of the German magazine Klang Und Ton.
Good Luck !
Ron
Guys,
I want to add something: Tony Gee, a respected Dutch designer, used the T18RE once and was very pleased with the result:
http://www.humblehomemadehifi.com/USB.html
His crossover, however, is not so simple and is not 6 dB....
Ron
I want to add something: Tony Gee, a respected Dutch designer, used the T18RE once and was very pleased with the result:
http://www.humblehomemadehifi.com/USB.html
His crossover, however, is not so simple and is not 6 dB....
Ron
I heard the Madisound SEAS coax kit (I think they call them Loki) at a club meeting. These sound very nice, kind of punchy. For part of the meeting I sat in front of the left speaker and could clearly hear the right one, and they were only slightly toed in.
The Lokis were bested that day only in the high frequencies by the Vifa Studio Kit, also from Madisound.
Both of these inexpensive kits beat Madisound's Fostex BK-16 folded horn by leaps and bounds. The folded horn sounded like a cheap boombox, IMO. Lots of overlapping resonances.
The Lokis were bested that day only in the high frequencies by the Vifa Studio Kit, also from Madisound.
Both of these inexpensive kits beat Madisound's Fostex BK-16 folded horn by leaps and bounds. The folded horn sounded like a cheap boombox, IMO. Lots of overlapping resonances.
I ordered one earlier today for use in a centre speaker. Nice to hear so many positive comments.
The Tony Gee crossover design looks very well thought out, but it was designed for an older version of the T18 driver than the one that is currently available in Loki kit from Madisound. I wonder if the current Loki crossover was designed specifically for the new version. If not has anyone used a filter that does take advantage of the possibility of lower crossover point that can be used for the new version of the T18 driver?
Hi Guys,
I assume you mean the H1333?
I haven't had time to read all this thread but I have a lot of experience with this driver. Use it in a medium size (~20l) sealed box, it needs the air cushion. When in a ported box it may go deep but the upper bass and mid sound a bit sloppy and lacking definition. Put it in a sealed box and use a single inductor with low resistance (for better damping factor) to get a 2nd order acoustic roll-off at your desired point. The tweeter, effectively being waveguide loaded can cope with a 2nd order acoustic roll-off just fine too.
The FR of this woofer is designed to be pretty flat in the free field, so don't expect to place it super close to any boundaries without the lower mid becoming a bit full sounding (some will like this of course).
The treble response is hard to get right by looking at the measurements because it is rather lumpy due to throat reflections in the join to the woofer.
Let me save you time, use a 900uH inductor on the woofer and a 2.2uF cap on the tweeter. If it seems a tad bright, experiment with a series resistor on the tweet, but I think its about right.
I assume you mean the H1333?
I haven't had time to read all this thread but I have a lot of experience with this driver. Use it in a medium size (~20l) sealed box, it needs the air cushion. When in a ported box it may go deep but the upper bass and mid sound a bit sloppy and lacking definition. Put it in a sealed box and use a single inductor with low resistance (for better damping factor) to get a 2nd order acoustic roll-off at your desired point. The tweeter, effectively being waveguide loaded can cope with a 2nd order acoustic roll-off just fine too.
The FR of this woofer is designed to be pretty flat in the free field, so don't expect to place it super close to any boundaries without the lower mid becoming a bit full sounding (some will like this of course).
The treble response is hard to get right by looking at the measurements because it is rather lumpy due to throat reflections in the join to the woofer.
Let me save you time, use a 900uH inductor on the woofer and a 2.2uF cap on the tweeter. If it seems a tad bright, experiment with a series resistor on the tweet, but I think its about right.
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