And I surmise the woofer will never asks all the 300W it is able to at modest domestic appartment level. All I need max on transcient is imo 109 dB peak max... maybe very short 112 dB peaks if Saturday nigth fever nostalgia. My average listening level : 85 to 90 dB max.
I really dislike the idea to to putt a big amount of resistor in front of a driver... the non colored resistor are expensive according my experience.
I really dislike the idea to to putt a big amount of resistor in front of a driver... the non colored resistor are expensive according my experience.
Okay, low wattage limit means you can use cheap 24 gage inductors in the crossover instead of expensive 15 or 11 gauge. I listen at 1/8 watt (my speaker is 98 db 1w1m) most of the time; occasional peaks on cannon shot of 1812 overture of 50 watts.
Many compression drivers on Constant Directivity horns need a 6dB/oct boost above 5kHz or so for a flat frequency response.
If that is your aim choose the series capacitor of a 12dB/oct passive crossover accordingly ie one with a 5k roll off and use the parallel inductor at 1.2kHz to steepen the roll off to -12dB.
If you make that work you won't have to pad down the tweeter quite as much by other means and with some extraordinary luck you might not need to pad at all (possible in theory but in reality this nearly never happens).
If that is your aim choose the series capacitor of a 12dB/oct passive crossover accordingly ie one with a 5k roll off and use the parallel inductor at 1.2kHz to steepen the roll off to -12dB.
If you make that work you won't have to pad down the tweeter quite as much by other means and with some extraordinary luck you might not need to pad at all (possible in theory but in reality this nearly never happens).
Hi,
That's nice, I keep it in mind. I think I will play with Xsim and Vituix after measurements of the horn/CD combo when choice is ok. At 800 hz plus, some gating for the measurement inside a room is possible if the horn is free of close surfaces (1.3 m in all the direction free of reflexions is possible at home with a horn).
Btw when talking of 1 m distance measurement for a horn, where to start from to place the mic, please ? 1 meter from the CD exit or the exit of the horn mouth ? I never measured a horn. I imagine plenty of thread here. I am not there already though.
FIrst is to see if technically feasible passive with the rigth horn/combo. ST260 or a flatter 360CE serie is appealing VS the audio store on shelves horns like in the Mezzo Calapamos for illustration.
If members experienced some nice 1" CD filtered passive as low as 800/900 hz yet sounded good full range to your ears , I am interrested to continue the list of the candidates in order to a budget aproximation of the project. VS a more classic classic three ways classic. Let say 200 euros max per 1" compression. I would have to trust you for the combo CD/horn choice. Keep in mind passive filtering is prefered.
That's nice, I keep it in mind. I think I will play with Xsim and Vituix after measurements of the horn/CD combo when choice is ok. At 800 hz plus, some gating for the measurement inside a room is possible if the horn is free of close surfaces (1.3 m in all the direction free of reflexions is possible at home with a horn).
Btw when talking of 1 m distance measurement for a horn, where to start from to place the mic, please ? 1 meter from the CD exit or the exit of the horn mouth ? I never measured a horn. I imagine plenty of thread here. I am not there already though.
FIrst is to see if technically feasible passive with the rigth horn/combo. ST260 or a flatter 360CE serie is appealing VS the audio store on shelves horns like in the Mezzo Calapamos for illustration.
If members experienced some nice 1" CD filtered passive as low as 800/900 hz yet sounded good full range to your ears , I am interrested to continue the list of the candidates in order to a budget aproximation of the project. VS a more classic classic three ways classic. Let say 200 euros max per 1" compression. I would have to trust you for the combo CD/horn choice. Keep in mind passive filtering is prefered.
Last edited:
For Vituix the front baffle is the reference point so your measurement should be referenced to that to get the most accurate simulation of the whole speaker.
DSP units are a really good way of prototyping a speaker when you aren't following someone else's plans. If you have a large stock of different passive parts, cut and try the passive way may be easy but if you don't the price could really stack up until you find the response you like.
Yes sure...and nowadays passive parts are expensive. Maybe the Camilla software on a Pi could be an affoardable way to make a P.O.C. and avoiding to spend for a miniDSP HD. Steep learning curve needed though and some more diy ...while I have plenty of diy dac to make a 2 ways...
Have read more about potential 1" CD and low exit... the BMS4550 advised or also 4552ND looks the best candidate reading DIYAUDIO posts. I would have to found more about the radian 475pb, but why reinvent the wheel? BMS4550 it will be or HF108 (R is the option for short studio or home listening???) if people find it better for this project. The HF108 non R has a lower Fs... maybe more confortable for phase things if lowish cut-off choice, I don't know !
So if I understood more or less : two options with the use of ST260 or CE360 : 24 db passive slope if near 800 hz/900 hz or 12 dB if more classic 1200 hz (and maybe expanse here to the ST280E horn choice) !
Maybe I am too much worried to cut off a 12" that high with my limited spl needs, often no more than 80/85 dB average (without the transcients peaks)... I fear to have too much thicky rich tonal with the 1200 hz but without trying myself I have to trust experienced members...
Have read more about potential 1" CD and low exit... the BMS4550 advised or also 4552ND looks the best candidate reading DIYAUDIO posts. I would have to found more about the radian 475pb, but why reinvent the wheel? BMS4550 it will be or HF108 (R is the option for short studio or home listening???) if people find it better for this project. The HF108 non R has a lower Fs... maybe more confortable for phase things if lowish cut-off choice, I don't know !
So if I understood more or less : two options with the use of ST260 or CE360 : 24 db passive slope if near 800 hz/900 hz or 12 dB if more classic 1200 hz (and maybe expanse here to the ST280E horn choice) !
Maybe I am too much worried to cut off a 12" that high with my limited spl needs, often no more than 80/85 dB average (without the transcients peaks)... I fear to have too much thicky rich tonal with the 1200 hz but without trying myself I have to trust experienced members...
Camilla and a Pi is cheap but yes not really straight forward for everyone. I use Jriver and it does not cost that much, other options are a plugin host or DAW type software that can run VST plugins. There are enough free versions of those but still there can be setup headaches if you are not a computer person. It is quite difficult to time sync multiple stereo DAC's but a single stereo DAC is enough to prototype one speaker to get the voicing as you like it as long as it interfaces with a computer.
The beauty of testing with an active crossover is that you can find out for yourself by building different pre-sets. Maybe you find out that you like the flexibility of adding extra EQ and the sound it produces or maybe you find that simple filters are your preference and you make a passive version quite easily to match the transfer function (taking care of impedance changes that won't be apparent in the active setup).
I am sure a Minidsp HD two channel is the easiest to avoid all the computer mess. But having Pi already, Iancanada clocks with multiple I2S outputs and several I2S inputs DAC, and enough amp. Seems to me the most logic to stay budget low. Some care to have I Imagine as matching the spl output of two different amps with the pot to match the voltage output for having the same gain.
Now I do not know nothing about the GUI of Camilla. I have already bichannel outside soundcard, E7500MX calibrated mic plus ECM 8000.
I saw the last measurement of Vineeth in mabat's ath4 thread https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7157492
Hummm, I understand also now why a 1400/1500 cut-off with such horn size... not that easy below because the roll off low end. That roll-off has to be a part of the low pass filter to make the overlapp flat with the bottom driver ! But this detail and my limited knowledge, I find this ST260 horn has a beautifull smooth diving towards the treble. I do not know how much more db dives for the power response with a classic 3 meters sweet spot. But if around -10 db at the top end, it should give a very good sounding, imho !
Now I do not know nothing about the GUI of Camilla. I have already bichannel outside soundcard, E7500MX calibrated mic plus ECM 8000.
I saw the last measurement of Vineeth in mabat's ath4 thread https://www.diyaudio.com/community/...-design-the-easy-way-ath4.338806/post-7157492
Hummm, I understand also now why a 1400/1500 cut-off with such horn size... not that easy below because the roll off low end. That roll-off has to be a part of the low pass filter to make the overlapp flat with the bottom driver ! But this detail and my limited knowledge, I find this ST260 horn has a beautifull smooth diving towards the treble. I do not know how much more db dives for the power response with a classic 3 meters sweet spot. But if around -10 db at the top end, it should give a very good sounding, imho !
Read through this for slope correction and high-pass function:
http://www.zaphaudio.com/hornconversion.html
(..of course a larger waveguide will provide a lower high-pass than this, but you should get the "idea".)
If I was doing a cheap and cheerful CD/Waveguide combo it would be:
https://audioxpress.com/article/test-bench-peerless-by-tymphany-dfm-2544r00-08-compression-driver
in this:
https://eminence.com/collections/waveguides-and-horn-flares/products/sst1#specifications
The waveguide will provide a slope character very similar to this (same waveguide, slightly different Peerless CD):
https://audioxpress.com/article/peerless-by-tymphany-dfm-2535r00-08-compression-driver
http://www.zaphaudio.com/hornconversion.html
(..of course a larger waveguide will provide a lower high-pass than this, but you should get the "idea".)
If I was doing a cheap and cheerful CD/Waveguide combo it would be:
https://audioxpress.com/article/test-bench-peerless-by-tymphany-dfm-2544r00-08-compression-driver
in this:
https://eminence.com/collections/waveguides-and-horn-flares/products/sst1#specifications
The waveguide will provide a slope character very similar to this (same waveguide, slightly different Peerless CD):
https://audioxpress.com/article/peerless-by-tymphany-dfm-2535r00-08-compression-driver
Hi fluid,
I am asking because I am ready to measure my implementation once the weather allows.
Is this true even for a Unity/Synergy type wave-guide, where the drivers for the different frequency band are offset from one another?
I am asking because I am ready to measure my implementation once the weather allows.
ah...this cdx-1-1730 is one of the 1" that goes low...900 hz w/o problem for domestic use. And less disto and IMD than a B&C DE250.
@ScottG, hello Scott, thanks for the valuable advices for the drivers and horns (as usual)... btw if not going the WG way because I feel it could get too much spendy or too much complex which can be related eachothers btw, I keeped the good idea of an Audiotechnology you already adviced elswhere... a little spendy above my budget for 330 euros : the Flexunits 15I52, but it hits the 91 dB mini I need for a cross-over with the 12PR320. But buy once cry once is maybe better TCO at the end. I am not on one or two loudspeaker a year... (this one will be my second diy only).
For the 1" if mabat's ST260, (ST280E -if higher XO) or 360CE is chose, this test you know by one of my countryfellows influenced me as well: the Peerless are an extraordinary Q/P indeed especially here being one of the few able of a low cut-off for a 1". For the double of the price the BMS is on the first podium step. The usual 18th Sounds all people get as one of the best 1" is said too much short though in the high end for a true "full range" 1" (contradiction I know but we talk of domestic levels ; ndlr for the readers that take the train). http://www.justdiyit.com/grand-comparatif-de-compressions-1-pouce/6/ : for the readers, the lowest score is the best note.
Btw, at the first beginning If going not Vott, I wanted to try some open baffle and the Juhazi member project with a 12" as open midbass and a good sealed below that, plus planars above the 12" has something theorically rigth to me... both was given up cause the budget + listening room possibilities (Vott are cheap in US not in France, the fault of Hiraga* (*:joke as he has the reputation of a very gentle and nice guy)
@ScottG, hello Scott, thanks for the valuable advices for the drivers and horns (as usual)... btw if not going the WG way because I feel it could get too much spendy or too much complex which can be related eachothers btw, I keeped the good idea of an Audiotechnology you already adviced elswhere... a little spendy above my budget for 330 euros : the Flexunits 15I52, but it hits the 91 dB mini I need for a cross-over with the 12PR320. But buy once cry once is maybe better TCO at the end. I am not on one or two loudspeaker a year... (this one will be my second diy only).
For the 1" if mabat's ST260, (ST280E -if higher XO) or 360CE is chose, this test you know by one of my countryfellows influenced me as well: the Peerless are an extraordinary Q/P indeed especially here being one of the few able of a low cut-off for a 1". For the double of the price the BMS is on the first podium step. The usual 18th Sounds all people get as one of the best 1" is said too much short though in the high end for a true "full range" 1" (contradiction I know but we talk of domestic levels ; ndlr for the readers that take the train). http://www.justdiyit.com/grand-comparatif-de-compressions-1-pouce/6/ : for the readers, the lowest score is the best note.
Btw, at the first beginning If going not Vott, I wanted to try some open baffle and the Juhazi member project with a 12" as open midbass and a good sealed below that, plus planars above the 12" has something theorically rigth to me... both was given up cause the budget + listening room possibilities (Vott are cheap in US not in France, the fault of Hiraga* (*:joke as he has the reputation of a very gentle and nice guy)
Last edited:
Hi diyiggy,
Before my REW decided to quit recognizing UMIK-I, I made some measurements, which indicated that on the pictured wave-guide the driver could arguably support about 900Hz cross-over. However, please note that several people recommended a cross over at quite higher frequencies - 1500Hz to 1800Hz - based on their assessment that "it sounded the best there".
Kindest regards,
M
Before my REW decided to quit recognizing UMIK-I, I made some measurements, which indicated that on the pictured wave-guide the driver could arguably support about 900Hz cross-over. However, please note that several people recommended a cross over at quite higher frequencies - 1500Hz to 1800Hz - based on their assessment that "it sounded the best there".
Kindest regards,
M
Yes, I realise that is my folly wanting to cross a 1" below the natural cut-off you're talking about. That Celestion has a crazy good reputation like some, Beyma 350, cheap RCF cd350, also to add to the list, etc for such 1200+ hz cut-off. In the link above, that Celestion was tested as well. That just I pointed out the envy of crossing much lower because a 12" loose its pistonic range way before at 600 hz max, so people make climb a 12" cause most usual horns and CD exhibit too much THD in that area or go the road of WAF give up with 15" and huge horns to cross that low (hey we all want a 300 hz cut-off with a full range CD/horn above...that is just complex and spendy), so better trade off than a climbing 12" to stay 2 ways !
That said the MEH is certainly a solution, but those horns are a little to straigth expansion and edy at the mouth... trade off, trade off !
But as said Pano above, once must sorting out what he believes to be good and what is working in real life : that's my idea too : reality check... experience of members matter !
That said the MEH is certainly a solution, but those horns are a little to straigth expansion and edy at the mouth... trade off, trade off !
But as said Pano above, once must sorting out what he believes to be good and what is working in real life : that's my idea too : reality check... experience of members matter !
Last edited:
Hi diyiggy,
Kindest regards,
M
I do not think that the frequencies I identified are "natural cut-off", and as you are probably aware, many people cross-over about 900Hz the (correctly selected) 1 inch drivers.
I have difficulty to decipher the "those horns are a little to straigth expansion and edy at the mouth", but I would encourage you to listen to one if you could before you make a final decision.
Kindest regards,
M
So far as I understand Kimmo's instructions for Vituix the baffle plane is where to measure to get the most accurate simulation if all the functions of Vituix will be used. If the MEH is not going to cross over to any other drivers then it is possible this does not matter so long as the drivers are all measured from the same position and no physical offsets are added in the software, i.e. the position should be 0,0,0 X,Y,Z,
Technically for a pure horn having the rotation axis be over the acoustic centre would give the most accurate 3D polar plot, but if you want to use that measurement with a baffled woofer in a simulation it would all get quite messy.
So, yes, maybe but maybe not 🙂
Hopefully you post the measurement somewhere, I have a box of those Aurasound drivers from a long ago shelved MEH idea.
Hi fluid,
thank you for the king Solomon-like reply. 🙂
Kindest regards,
M
thank you for the king Solomon-like reply. 🙂
This was, what I concluded and did.
I would really like to do so. But, REW is complaining that UMIK-I is providing unsupported data format., I reinstalled it, but to no avail.
Kindest regards,
M
The horn itself is a big determinant in how low any driver can cross safely. The ST260 or something similar has it's radiation impedance peak at about 1.5K and starts to drop quite rapidly below that.
You can see measurements of the ST260 KVAR with a Peerless Driver in Vineeth's thread you can even download the Vituix project file and have a play if you want.
https://www.diyaudio.com/community/threads/a-3-way-design-study.376620/post-7157498
That driver is not super happy crossing at much less than 1200Hz particularly if you use a capacitor as waveguide compensation. Actively it is easier to shelve the boost out to maintain as much low end as possible.
If you are really set on crossing down towards 800Hz and not to use a very large horn then the BMS 4550 is one of the only drivers that can go it alone without the support of a low loading horn. BMS drivers are built like a tank and there is rarely any criticism of their sound so while it might be expensive compared to the Peerless (that are really dirt cheap for the quality), compared to other more premium drivers the price is pretty reasonable.
Almost any driver could do it if the SPL is limited enough but that just seems like a fudge to me.
thanks for that.
The KVAR à la JLMC seemed less smooth than the first ST260 iterration, I read. I wonder if someone tried already the 280E version with the higher crossover mandatory you talked about ?