Hi y'all,
So I figured I'd post these up, since I rave about this driver so much. And there's a lot of questions about the treble it produces. First, I'll describe my setup because I've found that can be rid a lot of question people ask when measurements don't "look" the way they expect. I used a Behringer ECM8000 microphone calibrated by Cross Spectrum Labs from 5hz 25khz, powered by a Blue Icicle. I used HolmImpulse pumped digitally into a Yamaha HTR in pure audio mode. The speaker was placed 1.2m above the floor, yielding an approximate 3.5ms clean IR.
The speaker is a 7L sealed 7 x 12" cabinet. Here's a visual:
Ok, here goes, On axis and IR:
Some controlled break up starting around 6khz. This VERY controlled IMO. Tri peaks from 8 to 14khz as well. And a big suck out at 16khz.
The impulse response is strange, but I got a similar result on 2 other pairs. Some reputable posters in the multi-way section said it's a bad IR, but means nothing. And others said this is typical of a FR driver because of the dust cap resonance or something. Over my head.
Now nearfield in a 7L box:
Probably only reliable up to 400hz. Also taken at a very low volume, so at normal listening levels this may be different. Would be nice to do ground plane, but not happening in my living room Maybe one day outside.
And off axis. 5, 25, 45 degrees, approximately:
This is better off axis control than I would have thought and remember from my previous measurements. I'm pretty pleased. It is ragged though. Something a typical 1" x 6.5" 2-way couldn't do in the critical 2khz range.
All in all I still say this driver is totally awesome. Sounds even better than it measures 😉
So I figured I'd post these up, since I rave about this driver so much. And there's a lot of questions about the treble it produces. First, I'll describe my setup because I've found that can be rid a lot of question people ask when measurements don't "look" the way they expect. I used a Behringer ECM8000 microphone calibrated by Cross Spectrum Labs from 5hz 25khz, powered by a Blue Icicle. I used HolmImpulse pumped digitally into a Yamaha HTR in pure audio mode. The speaker was placed 1.2m above the floor, yielding an approximate 3.5ms clean IR.
The speaker is a 7L sealed 7 x 12" cabinet. Here's a visual:
Ok, here goes, On axis and IR:
Some controlled break up starting around 6khz. This VERY controlled IMO. Tri peaks from 8 to 14khz as well. And a big suck out at 16khz.
The impulse response is strange, but I got a similar result on 2 other pairs. Some reputable posters in the multi-way section said it's a bad IR, but means nothing. And others said this is typical of a FR driver because of the dust cap resonance or something. Over my head.
Now nearfield in a 7L box:
Probably only reliable up to 400hz. Also taken at a very low volume, so at normal listening levels this may be different. Would be nice to do ground plane, but not happening in my living room Maybe one day outside.
And off axis. 5, 25, 45 degrees, approximately:
This is better off axis control than I would have thought and remember from my previous measurements. I'm pretty pleased. It is ragged though. Something a typical 1" x 6.5" 2-way couldn't do in the critical 2khz range.
All in all I still say this driver is totally awesome. Sounds even better than it measures 😉
nice build!
did you put grills/screens in front of the drivers?
how does the "dropping" hf affect listening enjoyment?
cheers
did you put grills/screens in front of the drivers?
how does the "dropping" hf affect listening enjoyment?
cheers
I actually measured with and without the frills. It surprisingly made very little difference. The posted measurement is without the grills.
Merci!
Thank you for this. Your mid-high measurement resembles what I saw with my first and only measurement of one of my Microtowers, which was taken nearfield about a cm from one of the front firing cones. I'll compare again when I get home today.
When you listen to music with your 7L boxes, do you apply any sort of filtering?
I've played a bit with a VST EQ, but have had very little time to experiment. Lately I've been satisfied with a mere 3db shelf added from ~ 10k up.
What was the measurement distance for the first one posted?
Thank you for this. Your mid-high measurement resembles what I saw with my first and only measurement of one of my Microtowers, which was taken nearfield about a cm from one of the front firing cones. I'll compare again when I get home today.
When you listen to music with your 7L boxes, do you apply any sort of filtering?
I've played a bit with a VST EQ, but have had very little time to experiment. Lately I've been satisfied with a mere 3db shelf added from ~ 10k up.
What was the measurement distance for the first one posted?
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Hey Von.ah,
They were measured at 1m.
I do apply filtering. I'll be adjusting some things now that I've measured to see how it sound. So far I've only cut about 2db from 1000hz and up to compensate for baffle step (probably not required for the castle). And added tons of bass boost to make up for the sealed cab. I use my computer to do it. They very basic eq I'm using on my computer is a bit limited, so I'll be looking to try something better.
They were measured at 1m.
I do apply filtering. I'll be adjusting some things now that I've measured to see how it sound. So far I've only cut about 2db from 1000hz and up to compensate for baffle step (probably not required for the castle). And added tons of bass boost to make up for the sealed cab. I use my computer to do it. They very basic eq I'm using on my computer is a bit limited, so I'll be looking to try something better.
Oh and I should mention that my cabs have a very small chamfer, so some of the high frequency variation may be diffraction. Planet 10's box plans call for much better diffraction control than I used. The up firing driver accomplishes that somewhat I imagine.
I know measurements aren't for everyone in the full range forum, but I thought I'd post this also.
I dug up my old measurements on 2 other EL70s. They were in a different cab though, Planet 10's mMar-Kel or something like that. A small vented cab. Anyways, the measurement conditions and cabs were different, but take a look.
My small cab is in blue, and the 2 others are red and green. One of those is enabled as well. So quite a variety here. Seems mine has more of a bulge from 1500 to 4000 but appears smoother transition across the baffle. One of Dave's samples does not have the 16khz suck out. Either way, that isn't audible if you ask me (flame war anyone 😀 ).
Hope this helps somebody. 🙂
I dug up my old measurements on 2 other EL70s. They were in a different cab though, Planet 10's mMar-Kel or something like that. A small vented cab. Anyways, the measurement conditions and cabs were different, but take a look.
My small cab is in blue, and the 2 others are red and green. One of those is enabled as well. So quite a variety here. Seems mine has more of a bulge from 1500 to 4000 but appears smoother transition across the baffle. One of Dave's samples does not have the 16khz suck out. Either way, that isn't audible if you ask me (flame war anyone 😀 ).
Hope this helps somebody. 🙂
It is very helpful to me, thank you. I am a living, breathing dichotomy in that I firmly believe in the philosophy and experience of full range drivers, yet my analytical mind yearns for more measurement data and the possibility of shrinking peaks and valleys in a frequency response graph.
Since you are adeptly ahead of me in your HOLM capabilities, I look forward to your developments. Do you envision working toward making the high frequency waggles less so?
Cheers, and keep the graphs coming! 😀
Since you are adeptly ahead of me in your HOLM capabilities, I look forward to your developments. Do you envision working toward making the high frequency waggles less so?
Cheers, and keep the graphs coming! 😀
A little. I'll use my computer to take out the 5800hz peak and fill in the 7200hz dip if that makes it sound better. I believe it will, but will be very slight. I'll let you know. I'll also use my computer to compensate to baffle step (the rise across the 1000hz range, I'm seeing 5.5db on my cab). For me using these in the nearfield, I'll likely only need a small amount of compensation. It'll all be by ear for that. The stuff above 10khz is entirely pointless to me. Very hard to hear those small variations. The suck out at 16khz look alarming, but extremely hard to hear. I might fill it in just for peace of mind.
For your castle, by nature I believe the up firing driver takes care of baffle step losses entirely. You may want to quiz up Dave about that. He's probably seen these measurements and would know if they're relatable to the castle better than me.
As I understand it, the EL70 was engineered with "built in BSC." I assume this was designed for a specific baffle size? 
Also, like you mention, the Castle arrangement somehow negates the need for a BSC. Therefore (what I've wondered but have yet asked), wouldn't the response of the EL70 in the MTs have a bit of a rise around that "built in BSC?" Feel like weighing in, Dave?
Also, like you mention, the Castle arrangement somehow negates the need for a BSC. Therefore (what I've wondered but have yet asked), wouldn't the response of the EL70 in the MTs have a bit of a rise around that "built in BSC?" Feel like weighing in, Dave?
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Looking at the spec sheet (and I'd say what my measurements show in the baffle step region agrees with the spec sheet) is that there isn't built in baffle step compensation. There is however a peak/dip combo right at the typical baffle step and diffraction point. The peak is shown at 425hz. My gate frequency is about 250hz so 425hz isn't very resolved in my plots. On top of that, I really wonder if that 425hz kick is real. The driver should be pistonic at that frequency.
So in essence, the peak/dip should smooth the baffle stepping and box diffraction, which is does quite nicely in my measurements, but not account for baffle step entirely.
I should possibly re-word what I said to say that there is about 3 or 4db of baffle losses combined with another 1 or 2db rise in the 1500 to 4000hz range on my sample. So the apparent baffle losses is about 5.5db total. Overall, it's one of the smoothest drivers I've seen from 200 to 2000hz in a box 😀
So in essence, the peak/dip should smooth the baffle stepping and box diffraction, which is does quite nicely in my measurements, but not account for baffle step entirely.
I should possibly re-word what I said to say that there is about 3 or 4db of baffle losses combined with another 1 or 2db rise in the 1500 to 4000hz range on my sample. So the apparent baffle losses is about 5.5db total. Overall, it's one of the smoothest drivers I've seen from 200 to 2000hz in a box 😀
Thanks for your thoughts. Your last sentence puts everything back in to perspective. 😀 That's the beauty of such a driver.
Tux, my friend, thank you for the measurements. We need more of this in the full range forum to lend credibility to claim that full range drivers have something special about them.
It is quite flat from 200 Hz to 2000 Hz. Some breakup beyond 3 kHz, but then I'm yet to see a driver that doesn't. I hear the Vifa driver in the Manzanita is pretty good.
Remember, it is the flatness and smoothness of the curve that make for good sound.
Do you have any time domain measurements? A waterfall plot? Maybe it's time to move on to ARTA. A waterfall plot is very revealing of resonances.
Another important quality is efficiency. What efficiency do these EL70s play at? They may be fine for a desktop system, but may sound compressed in a bigger system. Efficiency is highly underrated IMO. It is one of the most important qualities for a transducer, especially if you want to capture the dynamics and essence of music.
It is quite flat from 200 Hz to 2000 Hz. Some breakup beyond 3 kHz, but then I'm yet to see a driver that doesn't. I hear the Vifa driver in the Manzanita is pretty good.
Remember, it is the flatness and smoothness of the curve that make for good sound.
Do you have any time domain measurements? A waterfall plot? Maybe it's time to move on to ARTA. A waterfall plot is very revealing of resonances.
Another important quality is efficiency. What efficiency do these EL70s play at? They may be fine for a desktop system, but may sound compressed in a bigger system. Efficiency is highly underrated IMO. It is one of the most important qualities for a transducer, especially if you want to capture the dynamics and essence of music.
Hi ra
All great points. I'm working on moving to the version 5 of REW. That has waterfalls and other great measurement systems. For this, I just wanted to know how to go about my eq'ing. Once I'm more familiar with REW I'll make a donation and possibly use it for measuring these.
I agree with you on the whole effeciency thing. It is very important. Again, I don't have this from using HolmImpulse.
From my listening impressions, I don't hear any objectional cone breakup/resonance/csd in the high frequencies. The effeciency is rated at 86db/1w. Comparing to my reference 2-way, I'd say this it's reasonable.
That's all I can offer for now. Hopefully in the summer I'll torture these with some power compression cycles and ground plane measurements. Other projects are in need of measurement though.
All great points. I'm working on moving to the version 5 of REW. That has waterfalls and other great measurement systems. For this, I just wanted to know how to go about my eq'ing. Once I'm more familiar with REW I'll make a donation and possibly use it for measuring these.
I agree with you on the whole effeciency thing. It is very important. Again, I don't have this from using HolmImpulse.
From my listening impressions, I don't hear any objectional cone breakup/resonance/csd in the high frequencies. The effeciency is rated at 86db/1w. Comparing to my reference 2-way, I'd say this it's reasonable.
That's all I can offer for now. Hopefully in the summer I'll torture these with some power compression cycles and ground plane measurements. Other projects are in need of measurement though.
My EL70eN are measured to 84.17dB sensitivity. But something tells me that the stock EL70 should be a little higher though.
About a 1/3-1/2 dB. Max unit to unit variation (sample size 48) of just over a dB
dave
+1 on that. Once someone sees that second driver on the TOP 😱 of the cabinet, well, they know these are not yer regular home theater ootz ootz ootz BS speakers...
/tongue-in-cheek-pseudo-chest-thumping
😀
That's allowed 😀 I'd really like to hear some castles/microTowers. ChrisB has invited me over to hear them. Gotta find an opportunity.
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