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A new kit coming from the good folks at PE: The AviaTrix
These have been running in my system for the last month, getting final voicing tweaks. No pictures yet, as they are still in bare MDF, but you can get an idea of their size from the drawing below. A little taller than the TriTrix, and a little less deep. A little more svelte looking, and perhaps a bit higher SAF as well.
High SPL and good low frequency extension are generally mutually exclusive in designs utilizing 5” drivers. -But not in this case: An f3 of 40 Hz and an f6 of 30 Hz can be expected while the design models up to 107 dB of SPL without abusing the published Xmax too much. -And yes, that is a 3” flared port on the front, which is required to keep the port velocity reasonable.
The tweeter is the new RS28F, and an impressive sounding tweeter it is. Forget the fact they have the capacity to cross very low or exhibit class leading distortion plots. Forget the great looks, fit and finish. Like a prima ballerina, they appear to my old ears to navigate the most complex passages with nary a misstep. PE and Usher have come up with something special here. I’ll be using this tweeter again.
The ND140-8 woofer is also new, and sets the Dayton performance bar higher in what I’d call the high value driver class. While I didn’t explore the 20 mm of Xlim in any great depth, I can say that a pair of these can play very clean, very loud, and very low in the enclosure below. When overdriven, the woofers appear to be suspension limited, and do not bottom out on the back plate, making them more likely to survive power abuse or the occasional explosion, train wreck, gun shots, etc. when watching DVDs at near realistic levels.
Like any high value driver, it has a couple of attributes that separate it from its high dollar cost-is-no-object brethren. The Qts is on the high side, and in most cases will limit its use to sealed enclosures. While the frame is adequate, and allows flush mounting without cutting a rebate, I think this driver deserves a cast aluminum frame. -But the ease of mounting will be a boon for many, and properly mounted, I heard no frame resonance issues. During early trials, I found the ND140 sounds quite good used full range, with its sins being those of omission. It could be easily used for a nearfield monitor or a full ranger with no or a very minimalist crossover.
While the ML-TL enclosure appears to be a simple vented floorstander, the enclosure internal height was carefully chosen so the quarter wave resonance was a bit higher in frequency than the port. This helped augment the response sag in what would otherwise have been an extended bass shelf alignment. This resulted in a nice slow inital roll off below 100 Hz of about 3 dB / octave until shortly before the f6 at 30 Hz, where it drops off the cliff, and reverts to the expected vented response rolloff.
The crossover: The RS28F is crossed roughly 4th order acoustic at 1000 Hz. and an overlapped 6th order acoustic transfer function on the woofer, which sum in phase quadrature. Like the TriTrix, it is a very simple network, with only 6 elements, -and two of them are resistors. Why did I cross so low in a floorstanding design? -Because I’m lazy, and when Wayne and I design the matching center channel, surrounds, etc., I won’t have to reinvent the crossover. The current topology provides a nice wide horizontal off-axis response when turned on its side.
AviaTrix Horizontal off Axis measurements:
The response dip around 3K is a tweeter diffraction artifact caused by the close proximity of the midwoofers. I'll be investigating this further to see what can be done about it, or if it fills in in the vertical plane. -Certainly during auditioning, it isn't all that noticeable.
EDIT: Further measurements indicate the dip at 3K is a non-issue. It fills in completely at 6 feet and beyond when measured on the design axis.
How do they sound? Clean is the word that comes to mind. -Very clean and balanced from top to bottom with surprisingly deep bass. There is no heavy hand at work here, but a smooth and seductive, airy sound, hence the feminine moniker. Tribal wisdom says a high Q driver in a vented design will end up sounding boomy, but not in this case. The transmission line configuration, the tuning, and the stuffing all seem to ameliorate any potential boom quite nicely. –Note on the impedance plot how the resonance is damped.
Those that prefer the full, lush sound of a good ol’ paper driver woofer may find the bass and lower midrange a little too clean and articulate for their tastes, but I think many will find the sound quite enjoyable. Extended listening sessions, some at high SPL’s, have not resulted in any fatigue.
In my opinion, this design augments, rather than replaces the TriTrix design. A little more upscale, with a little more expense attached, and a slightly different sound.
For the extra $$$, the AviTrix will play lower and louder than the TriTrix. Once the crossover design is finalized, I understand there will be kit offerings from PE similar to the TriTrix designs.
C
These have been running in my system for the last month, getting final voicing tweaks. No pictures yet, as they are still in bare MDF, but you can get an idea of their size from the drawing below. A little taller than the TriTrix, and a little less deep. A little more svelte looking, and perhaps a bit higher SAF as well.
High SPL and good low frequency extension are generally mutually exclusive in designs utilizing 5” drivers. -But not in this case: An f3 of 40 Hz and an f6 of 30 Hz can be expected while the design models up to 107 dB of SPL without abusing the published Xmax too much. -And yes, that is a 3” flared port on the front, which is required to keep the port velocity reasonable.
The tweeter is the new RS28F, and an impressive sounding tweeter it is. Forget the fact they have the capacity to cross very low or exhibit class leading distortion plots. Forget the great looks, fit and finish. Like a prima ballerina, they appear to my old ears to navigate the most complex passages with nary a misstep. PE and Usher have come up with something special here. I’ll be using this tweeter again.
The ND140-8 woofer is also new, and sets the Dayton performance bar higher in what I’d call the high value driver class. While I didn’t explore the 20 mm of Xlim in any great depth, I can say that a pair of these can play very clean, very loud, and very low in the enclosure below. When overdriven, the woofers appear to be suspension limited, and do not bottom out on the back plate, making them more likely to survive power abuse or the occasional explosion, train wreck, gun shots, etc. when watching DVDs at near realistic levels.
Like any high value driver, it has a couple of attributes that separate it from its high dollar cost-is-no-object brethren. The Qts is on the high side, and in most cases will limit its use to sealed enclosures. While the frame is adequate, and allows flush mounting without cutting a rebate, I think this driver deserves a cast aluminum frame. -But the ease of mounting will be a boon for many, and properly mounted, I heard no frame resonance issues. During early trials, I found the ND140 sounds quite good used full range, with its sins being those of omission. It could be easily used for a nearfield monitor or a full ranger with no or a very minimalist crossover.
While the ML-TL enclosure appears to be a simple vented floorstander, the enclosure internal height was carefully chosen so the quarter wave resonance was a bit higher in frequency than the port. This helped augment the response sag in what would otherwise have been an extended bass shelf alignment. This resulted in a nice slow inital roll off below 100 Hz of about 3 dB / octave until shortly before the f6 at 30 Hz, where it drops off the cliff, and reverts to the expected vented response rolloff.
The crossover: The RS28F is crossed roughly 4th order acoustic at 1000 Hz. and an overlapped 6th order acoustic transfer function on the woofer, which sum in phase quadrature. Like the TriTrix, it is a very simple network, with only 6 elements, -and two of them are resistors. Why did I cross so low in a floorstanding design? -Because I’m lazy, and when Wayne and I design the matching center channel, surrounds, etc., I won’t have to reinvent the crossover. The current topology provides a nice wide horizontal off-axis response when turned on its side.
AviaTrix Horizontal off Axis measurements:
The response dip around 3K is a tweeter diffraction artifact caused by the close proximity of the midwoofers. I'll be investigating this further to see what can be done about it, or if it fills in in the vertical plane. -Certainly during auditioning, it isn't all that noticeable.
EDIT: Further measurements indicate the dip at 3K is a non-issue. It fills in completely at 6 feet and beyond when measured on the design axis.
How do they sound? Clean is the word that comes to mind. -Very clean and balanced from top to bottom with surprisingly deep bass. There is no heavy hand at work here, but a smooth and seductive, airy sound, hence the feminine moniker. Tribal wisdom says a high Q driver in a vented design will end up sounding boomy, but not in this case. The transmission line configuration, the tuning, and the stuffing all seem to ameliorate any potential boom quite nicely. –Note on the impedance plot how the resonance is damped.
Those that prefer the full, lush sound of a good ol’ paper driver woofer may find the bass and lower midrange a little too clean and articulate for their tastes, but I think many will find the sound quite enjoyable. Extended listening sessions, some at high SPL’s, have not resulted in any fatigue.
In my opinion, this design augments, rather than replaces the TriTrix design. A little more upscale, with a little more expense attached, and a slightly different sound.
For the extra $$$, the AviTrix will play lower and louder than the TriTrix. Once the crossover design is finalized, I understand there will be kit offerings from PE similar to the TriTrix designs.
C
Attached Files
1kHz xpt? Me likey!:D
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