I thought I might take the plunge and build my first TL based on the successful 'Ariel'........ with a difference.
Full active, bi-amped, and using Vifa XT25TG-30-04.
The reason is simple enough, I have the gear already and I want to build something that sounds properly good.
Question is, is this a project worth pursuing?
Would the 'magic' of the Ariel be lost by changing the tweeter and going active?
Anything likely to go wrong with this idea?
I realize they won't sound like the real thing, but I think they could probably measure up to the original in they're own ways.
Any thoughts?
Thanx, Mick
Full active, bi-amped, and using Vifa XT25TG-30-04.
The reason is simple enough, I have the gear already and I want to build something that sounds properly good.
Question is, is this a project worth pursuing?
Would the 'magic' of the Ariel be lost by changing the tweeter and going active?
Anything likely to go wrong with this idea?
I realize they won't sound like the real thing, but I think they could probably measure up to the original in they're own ways.
Any thoughts?
Thanx, Mick
Going active and changing the tweeter makes it a new speaker. What are you using for a crossover? Straight symmetric slopes probably won't cut it.
If you have or intend to buy calibrated measurement gear, you should be able to get good results. Even so, plan on lots of trial and error, as you dial in the slopes and EQ. I'm not sure where Lyn crossed, but you might need to run it a little higher than 2K with the XT25. Other tweeters do a bit better lower (my preference)
Not that Lyn didn't come up with a good TL design, but you might want to try out Martin King's TL calculator. Not a direct comparison, but I build an Ariel inspired TL for some Focal drivers I had by scaling it up in proportion to Sd. Sounded nice. Then I plugged my drivers into Martin King' TL worksheet. A heck of a lot easier to build and worked a little better with my drivers.
In my small bedroom the TL's provided nice full range reproduction, without the need for a sub. I since have moved in the direction of three way speakers and have decided that the hassle of building a TL is not worthwhile. The TLs are now doing surround duty. Of course, YMMV.
Enjoy your project.
If you have or intend to buy calibrated measurement gear, you should be able to get good results. Even so, plan on lots of trial and error, as you dial in the slopes and EQ. I'm not sure where Lyn crossed, but you might need to run it a little higher than 2K with the XT25. Other tweeters do a bit better lower (my preference)
Not that Lyn didn't come up with a good TL design, but you might want to try out Martin King's TL calculator. Not a direct comparison, but I build an Ariel inspired TL for some Focal drivers I had by scaling it up in proportion to Sd. Sounded nice. Then I plugged my drivers into Martin King' TL worksheet. A heck of a lot easier to build and worked a little better with my drivers.
In my small bedroom the TL's provided nice full range reproduction, without the need for a sub. I since have moved in the direction of three way speakers and have decided that the hassle of building a TL is not worthwhile. The TLs are now doing surround duty. Of course, YMMV.
Enjoy your project.
Thanks BobEllis,
The crossover is a Behringer CX3400, so 4th order symmetrical slopes seem to be pretty unavoidable without spending up big again, although I could well do something about that down the track.
I agree it would be 'a new speaker'. The XT25 has it's own signature sound, the scan-speak in the original design has a different sound again. The Ariel is crossed @3.8k, I don't like the XT25 crossed much lower than 3k, even with the L/R24dB slopes (even though I measured these tweeter @ fs475Hz) there is audible distortion down there.
Although I have never heard the Ariels personally, by all accounts I know anything about, they are held in fairly high regard for their great mids and bass, (quality, not quantity) so I figured, crossing at a similar point would give a good chance of success, however different sounding.
Like you, I am only filling a fairly small room.
Mick.
The crossover is a Behringer CX3400, so 4th order symmetrical slopes seem to be pretty unavoidable without spending up big again, although I could well do something about that down the track.
I agree it would be 'a new speaker'. The XT25 has it's own signature sound, the scan-speak in the original design has a different sound again. The Ariel is crossed @3.8k, I don't like the XT25 crossed much lower than 3k, even with the L/R24dB slopes (even though I measured these tweeter @ fs475Hz) there is audible distortion down there.
Although I have never heard the Ariels personally, by all accounts I know anything about, they are held in fairly high regard for their great mids and bass, (quality, not quantity) so I figured, crossing at a similar point would give a good chance of success, however different sounding.
Like you, I am only filling a fairly small room.
Mick.
Something gives me a funny feeling your right on the money, the CX3400 simply may not have the scope to cope. This was the main problem I could foresee, the CX3400 can only shift phase 180 deg. nor can the roll off rate be adjusted, certainly a fly in the ointment.
On the positive side, there seems to be little or no FR or phase shaping below the XO point, leading me to believe that the sweet mids and tight bass are more a product of a well designed box. The XT25 to my ear at least has a nice sound once in its proper operating range, which as you suggest, kind of leaves the crossover as the main foreseeable hurdle.
With my limited knowledge, I really can't see any other major indicators that might suggest a step in the wrong direction. Actually, to be fair IME, the crossover is ALWAYS the biggest hurdle!!! ;-)
Thanx again.
On the positive side, there seems to be little or no FR or phase shaping below the XO point, leading me to believe that the sweet mids and tight bass are more a product of a well designed box. The XT25 to my ear at least has a nice sound once in its proper operating range, which as you suggest, kind of leaves the crossover as the main foreseeable hurdle.
With my limited knowledge, I really can't see any other major indicators that might suggest a step in the wrong direction. Actually, to be fair IME, the crossover is ALWAYS the biggest hurdle!!! ;-)
Thanx again.
I am running these drivers in a BR mtm configuration at present, active 2 way with a zobel and 1st order slope on one of the p13wh's and was planning to keep that in place to see how it goes. To be Honest, I wasn't sure if this had already been compensated for with the savvy box design or the crossover itself. Although I am running active crossovers at present, I do a little passive 'shaping'. Can the DXC2496 do BSC?
The Behringer is far too generic, so I'd suggest MiniDSP. The P13 is a tiny driver with limited extension. The Ariel is also quite complex - I don't see the point when you really need more to get what I would call "real bass." So I'd also suggest, go the next step and make it 3 way with some larger decent woofers.
In the past I ran some TL speakers, much simpler, with P17. It's here:
Red Spade Audio: DIY Transmission Line Speakers
Even then, I soon found I preferred the bass from Rythmik servo subs.
In the past I ran some TL speakers, much simpler, with P17. It's here:
Red Spade Audio: DIY Transmission Line Speakers
Even then, I soon found I preferred the bass from Rythmik servo subs.
I do like real bass, and I need it too, but it can probably wait for little while anyhow, till then, she's nize 'n tite, will make a good sleeping partner, hell, if ya can't have both and must choose only one, i choose tight. I forgot to mention I'm (like a lot of others ATM) on a tight budget.
One of the reasons for picking on the Ariel is I need a challenge right now that is not going to end in total misery sound wise.
Thanx for the link, I have heard the LSK TL (I lived in Keilor downs back in '99), to be honest, the bass was nice enough, but it didn't captivate me, I much prefer the overall sound of the Krix Lyrix (similar price when all is said and done) TBH. ;-)
One of the reasons for picking on the Ariel is I need a challenge right now that is not going to end in total misery sound wise.
Thanx for the link, I have heard the LSK TL (I lived in Keilor downs back in '99), to be honest, the bass was nice enough, but it didn't captivate me, I much prefer the overall sound of the Krix Lyrix (similar price when all is said and done) TBH. ;-)
Caution, just because you're going active doesn't mean you don't need to design a proper crossover. I made the same mistake because that's what I kept reading; just use active 4th-order slopes, it will sound great. It sounded crap. You need to consider phase, acoustic vs electrical slopes, BSC, driver correction filters. From the Ariel website:
"The whole process of crossover tuning took about 3 months, checking and re-checking with MLSSA and LMS each time I tried a slightly different crossover. 15 versions later, I was done"
Your speaker will look like an Ariel, but it won't sound as good. An active crossover is no panacea. It's still tough to design a great sounding speaker. IMO, a Behringer 3400 is a non-starter. The only way I could see a 3400 with an Ariel is to build the Ariel exactly as designed, and use the Behringer to cross over to a woofer.
"The whole process of crossover tuning took about 3 months, checking and re-checking with MLSSA and LMS each time I tried a slightly different crossover. 15 versions later, I was done"
Your speaker will look like an Ariel, but it won't sound as good. An active crossover is no panacea. It's still tough to design a great sounding speaker. IMO, a Behringer 3400 is a non-starter. The only way I could see a 3400 with an Ariel is to build the Ariel exactly as designed, and use the Behringer to cross over to a woofer.
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Thanx guys,
I have been active for a while now, the FIRST thing I learned about it was that it still needs shaping: for BSC and so forth, and yes I can ALWAYS hear the crossover, it doesn't matter where it is set, I can still hear it. I suspect this is phase issues I am hearing (the ones that active apparently doesn't suffer from), or do I suspect wrong?
Can better physical alignment help here?
Or does that kind of mean, active crossovers are almost a complete waste of time. In my experience, it is actually MORE difficult to cross to a sub with success than it is to cross the mids to the tweeter, which is not the same as saying that mids to tweet is easy!! Just an observation. Although having said that, it probably doesn't help much that my lounge room has 6dB cabin gain.
So abandon and re-think then??
I have been active for a while now, the FIRST thing I learned about it was that it still needs shaping: for BSC and so forth, and yes I can ALWAYS hear the crossover, it doesn't matter where it is set, I can still hear it. I suspect this is phase issues I am hearing (the ones that active apparently doesn't suffer from), or do I suspect wrong?
Can better physical alignment help here?
Or does that kind of mean, active crossovers are almost a complete waste of time. In my experience, it is actually MORE difficult to cross to a sub with success than it is to cross the mids to the tweeter, which is not the same as saying that mids to tweet is easy!! Just an observation. Although having said that, it probably doesn't help much that my lounge room has 6dB cabin gain.
So abandon and re-think then??
Phasing issues don't differ between a passive and active crossover, they need to be considered either way. If your tweeter is already dropping at 6dB/octave and the mid-woof is dropping at 2nd order, an active crossover with symmetrical slopes will be a bit of a mess. Almost all tweeters and mid-woof combos are changing phase by the time they cross. Then there's time delay on the woofer vs the tweeter. That's why a 2nd-order woofer with third-order tweeter filter is the most common crossover, resulting in a 4th-order Linkwitz-Riley acoustic filter.
You have to design an active crossover, just like you have to design a proper passive, whether you're crossing to a tweeter or a sub. Most people don't cross appropriately to a sub. I use sealed mains, so I have three choices to cross to the sub.
1) I can run the mains full range and use a Linkwitz-Riley second-order Low Pass at 50 Hz (minus 6dB point of mains)
2) or I can use a BW2 HP @ 70 Hz on the mains (-3dB point), which gives me a 4th order Linkwitz-Riler on the mains, and also filter the sub LR4
3) or lastly, I can cross to a woofer at a higher frequency (120-300 Hz for example) and filter both the sub and mains with symmetrical slopes (e.g. LR4).
If my speakers were ported, I could run the subs full range and use a 4th order LP at the -6dB point, or block the ports and do 2) above, or I could go at least an octave above F3 and use fourth order HP and LP crossovers.
I know some people can't hear any degradation from a crossover. In my system I hear the crossover as a slight lack of transparency and a bit of added grit. In return I can play louder without stress. It's a trade-off. Right now I'm running the mains full range with an LR2 Low Pass, but I change my mind periodically.
I use a pair of Bamberg Sound Labs Series 5 MTM monitors. I doubt if I could reproduce all the subtleties of the crossover with my Marchand XM44, especially with the measuring gear I have now, but maybe one day I'll try. For now I'm happy with passive mains and an active sub.
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This is an article from the Ariel ME2 pages........
If you're contemplating deep and natural-sounding bass for the Ariel or ME2, steer clear of the 10" to 15" poly-cone subwoofers that are so common these days.
The first reason? Polypropylene simply isn't a very rigid material; it isn't much more rigid than Tupperware (tm), and can easily have that characteristic "plastic" sound when it is used for cones larger than 8 inches. The "give" of the soft cone results in higher IM distortion than stiffer cone materials like treated paper, Kevlar, or carbon-fiber/paper composites. There's a good reason you don't see polypropylene used in load-bearing applications; it begins to "creep" and deform at fairly low values of mechnical stress. Treated paper, Kevlar, and carbon-fiber behave differently, and tend to be rigid up to the point of deformation. This translates into low-distortion up to the point of "cone cry", when the cone material enters breakup modes. By comparison, polypropylene flexes even at moderate levels of acceleration. This smooths the frequency response at the expense of increased distortion.
The second reason? Most well-reviewed "audiophile" drivers have magnetic circuits that are no better than consumer-grade; it just isn't a priority, since hi-fi magazines don't care much about IM distortion in speakers. In the real world, though, IM distortion is a very important consideration. Few bass drivers have magnet systems optimized for low IM distortion; the only ones I know of are expensive professional studio monitor drivers from JBL, Altec, and TAD, and the Scan-Speak drivers for consumer use. The Scan-Speaks aren't exactly cheap either, but they cost a lot less than the $350 to $800 retail price for prosound drivers.
(If you want the ultimate and are not deterred by cost, size, or weight, check out Stig Erik Tangen's Almighty Subwoofers page, which features a 15" JBL 2226G in a massive 220 litre 160kg sand-loaded enclosure. Point your browser to: http://www.speakerbuilding.com/amateur/tangen_sub2.html)
When it comes to bass, the perception of "speed" has only moderate correlation with overall transient response, and a great deal to do with low IM distortion and freedom from stored energy in the cone or cabinet. This is perceived as resolution, tactility, or "slam," and is the hallmark sound of electrostatic and full-range horn systems. Even though electrostats are famous for near-perfect impulse response, and horns for so-so impulse response, both types share remarkably low IM distortion in comparison with conventional dynamic drivers.
If you want a direct-radiator woofer to have that kind of "snap" and presence, seek out drivers with stiff cones and low IM distortion. (By the way, long excursion "specs" no more guarantee low distortion than high power amplifiers assure good sound. Quantity and quality are not the same thing.)
I can add a bit of thumpity thump thump later then, if I can just get the mains to operate satisfactorily. A challenge, but then, aren't all 'from scratch' projects?
If you're contemplating deep and natural-sounding bass for the Ariel or ME2, steer clear of the 10" to 15" poly-cone subwoofers that are so common these days.
The first reason? Polypropylene simply isn't a very rigid material; it isn't much more rigid than Tupperware (tm), and can easily have that characteristic "plastic" sound when it is used for cones larger than 8 inches. The "give" of the soft cone results in higher IM distortion than stiffer cone materials like treated paper, Kevlar, or carbon-fiber/paper composites. There's a good reason you don't see polypropylene used in load-bearing applications; it begins to "creep" and deform at fairly low values of mechnical stress. Treated paper, Kevlar, and carbon-fiber behave differently, and tend to be rigid up to the point of deformation. This translates into low-distortion up to the point of "cone cry", when the cone material enters breakup modes. By comparison, polypropylene flexes even at moderate levels of acceleration. This smooths the frequency response at the expense of increased distortion.
The second reason? Most well-reviewed "audiophile" drivers have magnetic circuits that are no better than consumer-grade; it just isn't a priority, since hi-fi magazines don't care much about IM distortion in speakers. In the real world, though, IM distortion is a very important consideration. Few bass drivers have magnet systems optimized for low IM distortion; the only ones I know of are expensive professional studio monitor drivers from JBL, Altec, and TAD, and the Scan-Speak drivers for consumer use. The Scan-Speaks aren't exactly cheap either, but they cost a lot less than the $350 to $800 retail price for prosound drivers.
(If you want the ultimate and are not deterred by cost, size, or weight, check out Stig Erik Tangen's Almighty Subwoofers page, which features a 15" JBL 2226G in a massive 220 litre 160kg sand-loaded enclosure. Point your browser to: http://www.speakerbuilding.com/amateur/tangen_sub2.html)
When it comes to bass, the perception of "speed" has only moderate correlation with overall transient response, and a great deal to do with low IM distortion and freedom from stored energy in the cone or cabinet. This is perceived as resolution, tactility, or "slam," and is the hallmark sound of electrostatic and full-range horn systems. Even though electrostats are famous for near-perfect impulse response, and horns for so-so impulse response, both types share remarkably low IM distortion in comparison with conventional dynamic drivers.
If you want a direct-radiator woofer to have that kind of "snap" and presence, seek out drivers with stiff cones and low IM distortion. (By the way, long excursion "specs" no more guarantee low distortion than high power amplifiers assure good sound. Quantity and quality are not the same thing.)
I can add a bit of thumpity thump thump later then, if I can just get the mains to operate satisfactorily. A challenge, but then, aren't all 'from scratch' projects?
Remember that Lyn wrote that quite a while ago. I agree with the point of looking for stiff well damped cones, but there has been a fair bit of attention paid to motor design in the years since polypropylene cones were popular. IM distortion is an issue that is at least somewhat addressed by a three way design's bandwidth limiting.
Even though you are in a small room, I agree with Paul that a three way with 7-8" woofer(s) would make sense if you aren't planning a sub right away. I find music seems awfully thin without the ability to reach at least into the 30s. Then again, I'm a bass plunker (not good enough to call myself a player).
Even though you are in a small room, I agree with Paul that a three way with 7-8" woofer(s) would make sense if you aren't planning a sub right away. I find music seems awfully thin without the ability to reach at least into the 30s. Then again, I'm a bass plunker (not good enough to call myself a player).
Hi Mick,
You mentioned that you would want to use a different tweeter to Lynns spec. Ed is quite right, its the excellent driver/crossover/cabinet integration that makes them so good. It will be a tough call to match it.
That also implies you can get your hands on some Vifa P13wh. Is that the case? I have a vested interest as they are discontinued and my Ariels' P13s surrounds have aged badly, loosing their flexibility. Do you have a source?
You mentioned that you would want to use a different tweeter to Lynns spec. Ed is quite right, its the excellent driver/crossover/cabinet integration that makes them so good. It will be a tough call to match it.
That also implies you can get your hands on some Vifa P13wh. Is that the case? I have a vested interest as they are discontinued and my Ariels' P13s surrounds have aged badly, loosing their flexibility. Do you have a source?
Yep, still a challenge. Designing an active crossover is easier than passive though, because it's a lot more predictable.
Well, I might as well throw my two cents into the discussion. The tedious part of the Ariel was "voicing" the thing; the crossover went through 13 variations, more than half of them ruler-flat (1/2 dB variation or less), but unfortunately they didn't sound flat subjectively (on pink-noise stimulus). The hard part was getting halfway acceptable measurements combined with subjective flatness.
If you want to try an active crossover with a different tweeter, sure, why not? Just be sure to measure and audition very carefully. In particular, aim for at least a 20 dB notch when the tweeter is inverted-phase for test purposes. This insures that the midbass and tweeter phase-track each other within a few degrees when the tweeters is reconnected to normal phase. Close phase-tracking (10 degrees or better) has always been a signature of my loudspeakers, so if you want an Ariel sound, aim for that.
Be sure to spend some quality time with pink-noise for subjective balancing, when you're ready for the last 1 to 1/2 dB trim adjustments. Note that pink-noise testing is merely confusing when the response is still rough or the drivers are not phase-tracking - it's impossible to tell which version of the crossover is "flat" when it's all over the place. At the end of the cycle, have the A/B switch in your hands at the listening position - when the changes are subtle, you're getting close, and getting up and twiddling with the crossover can erase acoustic memory. Loud clicks from the power amp, or playing the noise too loudly, can also erase acoustic memory, so avoid those conditions.
What you want is the difference between "almost-right" and "just-right". When a speaker is really flat it becomes much easier to zero in to flat response. When a speaker is rough, it's very difficult to tell whether a change is an improvement - changes merely sound "different", which isn't helpful.
As for the TL, I agree with the previous comments. The Ariels were designed in 1993 for a good friend that owned stacked Quad ESL57's, which is why they mimic the Quad ESL57 sound. Not an accident. But I'd be the first to agree that a clean-sheet-of-paper TL design would probably be better-sounding than original Ariel - however, I still think two isolated TL's are a better choice than a single TL with a shared chamber for the two midbass drivers.
P.S. If anyone wants to sell their pair of good condition ME2's (no disintegrating midbass units or blown tweeters, please), let me know. I'd like to sell my very expensive Dynaudio CS X center speaker and replace it with an exact match for my Ariels.
If you want to try an active crossover with a different tweeter, sure, why not? Just be sure to measure and audition very carefully. In particular, aim for at least a 20 dB notch when the tweeter is inverted-phase for test purposes. This insures that the midbass and tweeter phase-track each other within a few degrees when the tweeters is reconnected to normal phase. Close phase-tracking (10 degrees or better) has always been a signature of my loudspeakers, so if you want an Ariel sound, aim for that.
Be sure to spend some quality time with pink-noise for subjective balancing, when you're ready for the last 1 to 1/2 dB trim adjustments. Note that pink-noise testing is merely confusing when the response is still rough or the drivers are not phase-tracking - it's impossible to tell which version of the crossover is "flat" when it's all over the place. At the end of the cycle, have the A/B switch in your hands at the listening position - when the changes are subtle, you're getting close, and getting up and twiddling with the crossover can erase acoustic memory. Loud clicks from the power amp, or playing the noise too loudly, can also erase acoustic memory, so avoid those conditions.
What you want is the difference between "almost-right" and "just-right". When a speaker is really flat it becomes much easier to zero in to flat response. When a speaker is rough, it's very difficult to tell whether a change is an improvement - changes merely sound "different", which isn't helpful.
As for the TL, I agree with the previous comments. The Ariels were designed in 1993 for a good friend that owned stacked Quad ESL57's, which is why they mimic the Quad ESL57 sound. Not an accident. But I'd be the first to agree that a clean-sheet-of-paper TL design would probably be better-sounding than original Ariel - however, I still think two isolated TL's are a better choice than a single TL with a shared chamber for the two midbass drivers.
P.S. If anyone wants to sell their pair of good condition ME2's (no disintegrating midbass units or blown tweeters, please), let me know. I'd like to sell my very expensive Dynaudio CS X center speaker and replace it with an exact match for my Ariels.
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