Greetings builders!
As the title suggests I’m trying to build a pair of Tapered Transmission Line enclosures (So>Sl, narrower at the exit) with Monacor SPH-60x; however there is a problem – there seems to be a little “shortage” of actual project on the internet. For some reason people seem to avoid this type of TL and prefer the expanding geometry even though the theory states that it is more advantageous (easy to get right, good frecv. response, small enclosure).
I’ve seen a few project for the expanding type TL with the Monacor SPH-60x, not to mention BIB’s and horns and bass-reflexes but I could only find one with the contracting geometry I’m looking for to build, it’s in French and it’s here - http://www.baieaudio.com/ftp/tl_baie_audio.pdf .
The french project looks like this:
Tuning frequency – 60hz (=Fs)
Sl/So=0.5, 300cm2…150cm2
Length – 123 cm
0.2 offset, and 2/3-3/4 stuffing, based on information from MJKing’s work, cabinet sizes not included.
At end of the document, the owner said that it was the best enclosure for the SPH-60x after building a bas reflex, TQWT and an open baffle - more bass, better defined, sweeter mids and richer highs too.
Not only that but I think I saw somewhere that a Qts of 0.4…0.5 (SPH60x has a Qts of 0.42) is the best for a tapered TL… so the French commentator might be right, it is the best enclosure for this driver.
There might be other projects on the internet but in german, it seems to be a very popular driver on this forum - hifi-forum.de … but I don’t speak german so I don’t know.
I’m not planning to build the French project unless it’s really good, I would prefer something smaller than 27 liters, and tuned lower then Fs (60Hz), however I am interested in a good transient response and open midrange and I don’t know how the cabinet design affects that. Other then that I still don’t know how to get them in a column shape without that triangle look or the cartoonish expanding skyscraper.
So… anybody had any experience with a Monacor SPH60x in a TL with contracting geometry?
As the title suggests I’m trying to build a pair of Tapered Transmission Line enclosures (So>Sl, narrower at the exit) with Monacor SPH-60x; however there is a problem – there seems to be a little “shortage” of actual project on the internet. For some reason people seem to avoid this type of TL and prefer the expanding geometry even though the theory states that it is more advantageous (easy to get right, good frecv. response, small enclosure).
I’ve seen a few project for the expanding type TL with the Monacor SPH-60x, not to mention BIB’s and horns and bass-reflexes but I could only find one with the contracting geometry I’m looking for to build, it’s in French and it’s here - http://www.baieaudio.com/ftp/tl_baie_audio.pdf .
The french project looks like this:
Tuning frequency – 60hz (=Fs)
Sl/So=0.5, 300cm2…150cm2
Length – 123 cm
0.2 offset, and 2/3-3/4 stuffing, based on information from MJKing’s work, cabinet sizes not included.
At end of the document, the owner said that it was the best enclosure for the SPH-60x after building a bas reflex, TQWT and an open baffle - more bass, better defined, sweeter mids and richer highs too.
Not only that but I think I saw somewhere that a Qts of 0.4…0.5 (SPH60x has a Qts of 0.42) is the best for a tapered TL… so the French commentator might be right, it is the best enclosure for this driver.
There might be other projects on the internet but in german, it seems to be a very popular driver on this forum - hifi-forum.de … but I don’t speak german so I don’t know.
I’m not planning to build the French project unless it’s really good, I would prefer something smaller than 27 liters, and tuned lower then Fs (60Hz), however I am interested in a good transient response and open midrange and I don’t know how the cabinet design affects that. Other then that I still don’t know how to get them in a column shape without that triangle look or the cartoonish expanding skyscraper.
So… anybody had any experience with a Monacor SPH60x in a TL with contracting geometry?
I know about the Kornett, you posted before in 2008 about it in another SPH-60x thread, but it presents no interest for me, way too large and way to complicated; i like the simplicity of the fullrange concept, and i'm searching for a way to make o column looking enclosure for this loudspeaker that will produce pleasant musical midrange above all else.
Like I (actually didn't) said, i chose the tapering architecture for the fact that it is the smallest and has the flattest frequency response in the low end... it's better at midrange than the bass-reflex and that's why i chose the TL. Plus it may be the best suited enclosure for the given parameters.
Like I (actually didn't) said, i chose the tapering architecture for the fact that it is the smallest and has the flattest frequency response in the low end... it's better at midrange than the bass-reflex and that's why i chose the TL. Plus it may be the best suited enclosure for the given parameters.
Greets!
They used MJK's Classic TL Alignment Tables to design it, so it should perform well based on my experience with TQWTs.
I've no experience with this driver, but I've been told it's a drop-in replacement for the old Radio Shack 40-1354, which I have experience with in various TL alignments including TQWT, so shrinking it and lowering its Fp will only make for less bass/higher F3. Just doing a quick calculation, I would want about 40 L for a 42 Hz tuning.
GM
I'm having the impression I haven't been understood.
I want a TL with tapering geometry, where the section narrows towards the open end, the one that is the smallest and shorter of the three geometries - tapered, straight and expanding. The expanding TL is called TQWT in the MJKing documents from quarter-wave.com not once but on numerous occasions, I don't even know if the tapered TL has any name or abbreviation.
I knew about the RS 40-1354 being a very similar driver, however the TQWT plans I've got from this forum where for a 36 liter enclosure so 42 l is more then allot and 42 hz is way to low for a driver with an fs probably above 60... or at least that's how i see things, but anyway i'm not interested in an expanding type TL. I don't know of any tapered TL with this driver.
When I said that i wanted to tune bellow 60 Hz (=fs) i was thinking about 50-53 Hz.
I want a TL with tapering geometry, where the section narrows towards the open end, the one that is the smallest and shorter of the three geometries - tapered, straight and expanding. The expanding TL is called TQWT in the MJKing documents from quarter-wave.com not once but on numerous occasions, I don't even know if the tapered TL has any name or abbreviation.
I knew about the RS 40-1354 being a very similar driver, however the TQWT plans I've got from this forum where for a 36 liter enclosure so 42 l is more then allot and 42 hz is way to low for a driver with an fs probably above 60... or at least that's how i see things, but anyway i'm not interested in an expanding type TL. I don't know of any tapered TL with this driver.
When I said that i wanted to tune bellow 60 Hz (=fs) i was thinking about 50-53 Hz.
No, you've been understood; I just suspect you've misunderstood GM. He (and I, having adopted it) usually uses the term TQWT in a traditional sense, i.e. for a reverse taper line, or the opposite of how it's commonly used today.
Either way, making a quick calculation of my own, it looks like he has a ~max flat alignment to 0.707Fs in mind, which is the lowest practical tuning in the majority of cases, probably with a high taper ratio (12:1 or more).
Either way, making a quick calculation of my own, it looks like he has a ~max flat alignment to 0.707Fs in mind, which is the lowest practical tuning in the majority of cases, probably with a high taper ratio (12:1 or more).
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Hi Krakatoa, i can not give you an answer, just some ideas.
The best thing to do is to work with MJK´s spreadsheet and find a compromise between size, geometry and SPL (frequency).
My own designs always have some narrowing of the line. For ease of contruction the line can be divided into several straight sections with different (smaller) cross sections.
For this driver i would excpect the cabinet could be tuned to 50 Hz og maybe even 45. This can be simulated with Martin J King´s software, which i can reccomend.
The best thing to do is to work with MJK´s spreadsheet and find a compromise between size, geometry and SPL (frequency).
My own designs always have some narrowing of the line. For ease of contruction the line can be divided into several straight sections with different (smaller) cross sections.
For this driver i would excpect the cabinet could be tuned to 50 Hz og maybe even 45. This can be simulated with Martin J King´s software, which i can reccomend.
Ok I get it, 42 hz is the lowest of all alignment for SPH-60x with a box of 40 liters, but i don't want to go that low so I can get away with less volume. Anyway, i know from a document in german/english from somewhere on the internet that the lowest frequency for this driver is 50Hz, so I take that as a point of reference.
I would recommend MJ King's software too, but it's not in (my) the budget so I'll just press the "skip" button. I'm planning to make the best estimation based on numerous projects and info I can find on the internet, Hornresp data, the free excel alignment calculator from quarter-wave.com etc. and buid 1-3 versions to see which is best. The simulations aren't 100% percent accurate, and the final judge is how I feel about the way it sounds in the room I'm using them.
I would recommend MJ King's software too, but it's not in (my) the budget so I'll just press the "skip" button. I'm planning to make the best estimation based on numerous projects and info I can find on the internet, Hornresp data, the free excel alignment calculator from quarter-wave.com etc. and buid 1-3 versions to see which is best. The simulations aren't 100% percent accurate, and the final judge is how I feel about the way it sounds in the room I'm using them.
OK, I chose the lowest practical Fp since you weren't specific. At 50 Hz, 20 L should suffice, though as I noted earlier, less is always less, so F3 will be higher than in a larger cab; though as you note, it may not be enough to matter in-room, but not being you or having your room I can only recommend cabs large enough to allow as much tuning flexibility as practical.
Regardless, good luck with it and please let us know what you built.
GM
Wow! what a big volume difference between a 40Hz and a 50hz cabinet.
I will take those 20 L @ 50Hz as a point of reference.
So far I'd say the enclosure should be 20-27 Liter, tuned to 50-53 Hz, with an S contraction of 75%-90% (Sl/So=0.25...0.1).
Yes, I will make my experience and final project public so that others too can benefit from it.
I will take those 20 L @ 50Hz as a point of reference.
So far I'd say the enclosure should be 20-27 Liter, tuned to 50-53 Hz, with an S contraction of 75%-90% (Sl/So=0.25...0.1).
Yes, I will make my experience and final project public so that others too can benefit from it.
Well, I guess due to the language barrier I didn't make myself clear; 20 liters will be adequate [suffice], but ideally would need to be ~32.86 L to get what i consider an acceptable size Vs F3 trade-off.
Basically what under-sizing for a given tuning means is the speaker may need more baffle step compensation [BSC] to get it tonally balanced in-room all the way down to near/at tuning, i.e. less efficient due to more insertion loss and its potential impact on the driver's critical mids that implies.
GM
Basically what under-sizing for a given tuning means is the speaker may need more baffle step compensation [BSC] to get it tonally balanced in-room all the way down to near/at tuning, i.e. less efficient due to more insertion loss and its potential impact on the driver's critical mids that implies.
GM
Well I finally found out how these loudspeakers sound and they sound much worse than I thought: the sounds seem to be somewhere behind a thick curtain because the higher components of the sounds are too weak or perhaps the lower components are too strong, i say that because the bass is pretty good even in a leaky test enclosure. This behavior reminds me of mid-bass drivers not full-rangers.
Overall I'd say this is a good driver but musically speaking, the timbre of this speaker is unpleasant; the female voice, flute and similar sounds have a clear missing part and an added nose like hum, which actually is much worse if the sound has richer 400-600Hz component. This is wrong... the tonal balance is wrong.
The worse thing is when i'm having the impression that I can't hear the higher sounds (that I'm interested in) because the volume is too low, even though it's loud.
I find this sound unacceptable. Is there anything that can be done without adding a tweeter (which I won't, I want a fullranger not a 2 way imitation)?
Is this a break in issue? in the sense that it's only temporary?
And by the way, some people actually add BSC to this driver!!! the reason is beyond my comprehension.
Overall I'd say this is a good driver but musically speaking, the timbre of this speaker is unpleasant; the female voice, flute and similar sounds have a clear missing part and an added nose like hum, which actually is much worse if the sound has richer 400-600Hz component. This is wrong... the tonal balance is wrong.
The worse thing is when i'm having the impression that I can't hear the higher sounds (that I'm interested in) because the volume is too low, even though it's loud.
I find this sound unacceptable. Is there anything that can be done without adding a tweeter (which I won't, I want a fullranger not a 2 way imitation)?
Is this a break in issue? in the sense that it's only temporary?
And by the way, some people actually add BSC to this driver!!! the reason is beyond my comprehension.
To "hm" - it crossed my mind that you used the sph-60x as an indirect driver because off the fact that it wasn't that impressive on it's own...
On the other hand I'm sure adding a tweeter would solve the situation (because i saw it on some forum) or at least my experiment today showed that is I add a second fullrange (smaller) driver in free air which sounds very thin makes the sound extremely pleasant/musical and realistic, not just an improvement, a solution.
What I'm wondering is if adding a second unit for the higher frequencies doesn't it mess up the point source thing for which the fullrangers are known?
How would a different fullranger whith better tonal balance sound in comparison to SPH-60x + Tweeter?
Or perhaps today's experiment with the second fullranger in free air only proved that dipoles sound better? while a tweeter would sound different.
To "picowallspeaker" - I changed everything that I could in the setup and this driver always sounds closed, the nose sound i managed to solve somehow... the test enclosure (a TL) that i tested today had a null above 200Hz and I wanted to see if that helps with the nose sound and it did (minimum driver offset), unless it's related to something else, but at least I do have a solution. The upper department are the problem, above about 4000 Hz, maybe even lower then that.
On the other hand I'm sure adding a tweeter would solve the situation (because i saw it on some forum) or at least my experiment today showed that is I add a second fullrange (smaller) driver in free air which sounds very thin makes the sound extremely pleasant/musical and realistic, not just an improvement, a solution.
What I'm wondering is if adding a second unit for the higher frequencies doesn't it mess up the point source thing for which the fullrangers are known?
How would a different fullranger whith better tonal balance sound in comparison to SPH-60x + Tweeter?
Or perhaps today's experiment with the second fullranger in free air only proved that dipoles sound better? while a tweeter would sound different.
To "picowallspeaker" - I changed everything that I could in the setup and this driver always sounds closed, the nose sound i managed to solve somehow... the test enclosure (a TL) that i tested today had a null above 200Hz and I wanted to see if that helps with the nose sound and it did (minimum driver offset), unless it's related to something else, but at least I do have a solution. The upper department are the problem, above about 4000 Hz, maybe even lower then that.
krakatoa,
look the measurements and the simulations of the single horns
of the KORNETT and compair it to other constructions,
look the sum impedanz no bass resonanz below 50 Hz
flat 4 Ohm, did you know how tube amps love it.
bass down to 34 Hz with lowest and linear membran movement.
kornettmess
in english in the middle
about what
look the measurements and the simulations of the single horns
of the KORNETT and compair it to other constructions,
look the sum impedanz no bass resonanz below 50 Hz
flat 4 Ohm, did you know how tube amps love it.
bass down to 34 Hz with lowest and linear membran movement.
kornettmess
in english in the middle
about what
The KORNETT is a as big as a geographic feature...
Bass is not my problem, the SPH-60x has plenty of it, and I'm not very demanding in this departent.
I want to know if there is a fix to the closed sound; if there isn't, I'm going to have to find another loudspeaker that suits my purpose, which is to bring the headphones kind of sound (detail, realism, musical) in my room - mainly for music.
Bass is not my problem, the SPH-60x has plenty of it, and I'm not very demanding in this departent.
I want to know if there is a fix to the closed sound; if there isn't, I'm going to have to find another loudspeaker that suits my purpose, which is to bring the headphones kind of sound (detail, realism, musical) in my room - mainly for music.
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