rick57 said:
Yep. Determine baffle shape and size by considering what kind of frequencyranges they need to perform. They are all compromisses.
Jussi
Ups. Sorry for the misinformation. Measurements are just 2nd and 3rd harmonic and level is seen in each measurement. W18 response goes up to 95dB at midrange. Pretty well inline with Seas own graphs.
Here is 25W at 95dB. Again ignore distorsion below 100Hz (too small cabinet). Pretty good -50dB result up to 250Hz. Not sure how much those 2nd harmonics die down with magnet support and 2nd order filter. I don't think I'll go for 4th order here since there are other issues to consider. Like the vertical radiation pattern that's already discussed here.
-50dB with 95dB SPL. This leads to conclusion of ~0,3% distorsion at 100dB or so using two drivers on each side. Not bad. W18s 3rd harmonic peak is a setback. Fortunately well known setback. It isn't bad since SPL is already very high 95dB leading to 100dB ~0,5% THD with two drivers. But it could be whole lot better. Below 1Khz W18 is extremely clean. Pretty demanding company for any tweeter...
Jussi
Here is 25W at 95dB. Again ignore distorsion below 100Hz (too small cabinet). Pretty good -50dB result up to 250Hz. Not sure how much those 2nd harmonics die down with magnet support and 2nd order filter. I don't think I'll go for 4th order here since there are other issues to consider. Like the vertical radiation pattern that's already discussed here.
-50dB with 95dB SPL. This leads to conclusion of ~0,3% distorsion at 100dB or so using two drivers on each side. Not bad. W18s 3rd harmonic peak is a setback. Fortunately well known setback. It isn't bad since SPL is already very high 95dB leading to 100dB ~0,5% THD with two drivers. But it could be whole lot better. Below 1Khz W18 is extremely clean. Pretty demanding company for any tweeter...
Jussi
Attachments
Jussi said:
Yes, I'm talking about your project. I realize they aren't done, but I think they already look really good. I'm sure once they are finished tehy'll look even better. Keep up the good work!
Well. Some progress. I got both speakers playing this evening. Very temporary setup, cables all around the place, tweeters with temp fastening and the whole panel not connected together. It works pretty much as a worst case scenario. Drivers are meant to be solidly connected to steelframe while woodpanels operate as dampeners. At the moment drivers are just clamped between panels and frame which causes some vibrations to the front panel when bass cones punch. Therefore I'd expect them to get only for the better when the construction is finished.
But overall. Very promissing. Disappearing act already works very well, sound is easy, fast and dynamic. Plenty of detail, impressive soundstage. Or then I just might miss some sleep... 😉
Crossover is 300Hz 2nd and 1800Hz 4th order Linkwitz-Riley at the moment. I'll try out 250Hz 2nd order lower cross since W18s work much better in that region distorsion vice. Proper driver fastening, solid panel installation, spine support, magnet and basket damping and spikes below the floorplate should improve things in the future...
Jussi
But overall. Very promissing. Disappearing act already works very well, sound is easy, fast and dynamic. Plenty of detail, impressive soundstage. Or then I just might miss some sleep... 😉
Crossover is 300Hz 2nd and 1800Hz 4th order Linkwitz-Riley at the moment. I'll try out 250Hz 2nd order lower cross since W18s work much better in that region distorsion vice. Proper driver fastening, solid panel installation, spine support, magnet and basket damping and spikes below the floorplate should improve things in the future...
Jussi
Ok. More tweaking. Crossover versio 3.2. Pretty much measured balance and I must say it doesn't go that much wrong in the room either.
Here on axis responses at 100cm distance with room responses at 250cm 1/6th octave smoothing. Response rise between 6-12Khz is related to uncalibrated Behringer microphone. No sibilance audible. Midrange level is rised 1dB after this measurement. Still promissing...
Only problem is that while I'd get these things ready I have to come along without speakers for a while. 🙂
Jussi
Here on axis responses at 100cm distance with room responses at 250cm 1/6th octave smoothing. Response rise between 6-12Khz is related to uncalibrated Behringer microphone. No sibilance audible. Midrange level is rised 1dB after this measurement. Still promissing...
Only problem is that while I'd get these things ready I have to come along without speakers for a while. 🙂
Jussi
Attachments
Hi Jussi
Maybe I’m too optimistic about OBs reducing room responses, or boxes with the dame drivers would be lumpier, but I would have thought they would be smother ~ what distances were the room responses measured at?
Cheers
Maybe I’m too optimistic about OBs reducing room responses, or boxes with the dame drivers would be lumpier, but I would have thought they would be smother ~ what distances were the room responses measured at?
Cheers
rick57 said:
2,5m away. At the listening position. 300ms window, 1/6th oct smooth. Room is very difficult and rest of the furniture aren't symmetrical against the speakers. I guess some of the differences between channels appear from there..
Jussi
Experience with 18 sound speakers 6ND430 in OB
Hello to every body,
I´m planing to redesign my 4-way OB line array speaker to a 3-way system. As tweeter I expect to use the Mundorf AMT 2430 (<5000Hz) and for the high mids 2 x Mundorf AMT 2830 ( 2000 - 5000Hz). Both types I have already used and appreciated it in my previous OB concept in D´Appolito configuration. These Spaekers are very dynamic and very musically with very low distorsion levels even at high output of >95dB.
For the bass and lower midrange I would like to use the Eigtheen Sound 6ND430 for their excellent reputation and flat SPL. To increase the emiting surface, two times four speakers in D`Appolito configuration should be able to support the high output of the AMT´s.
Does somebody have experience with such drivers in an OB system? In addition I would like to know where I can find measurements of this speaker such as waterfall diagraphs and impuls response? The German distributor could not help in this case.
Any info will be highly appreciated.
Hello to every body,
I´m planing to redesign my 4-way OB line array speaker to a 3-way system. As tweeter I expect to use the Mundorf AMT 2430 (<5000Hz) and for the high mids 2 x Mundorf AMT 2830 ( 2000 - 5000Hz). Both types I have already used and appreciated it in my previous OB concept in D´Appolito configuration. These Spaekers are very dynamic and very musically with very low distorsion levels even at high output of >95dB.
For the bass and lower midrange I would like to use the Eigtheen Sound 6ND430 for their excellent reputation and flat SPL. To increase the emiting surface, two times four speakers in D`Appolito configuration should be able to support the high output of the AMT´s.
Does somebody have experience with such drivers in an OB system? In addition I would like to know where I can find measurements of this speaker such as waterfall diagraphs and impuls response? The German distributor could not help in this case.
Any info will be highly appreciated.
Mundorf at OB
Hi
Hell and Sky, not exactly the 6ND430 but the 10NDA520 at:
http://www.diyaudio.com/forums/showthread.php?postid=1197093#post1197093
"http://www.diyaudio.com/forums/showthread.php?postid=1197093#post1197093"
Along this thread many speakers were discussed and I also proposed the Mundorf AMT's. It might be interresting to have a first hand experiance or some measurements from your last project?
May be you can post some pictures there?
Greetings
Michael
Hi
Hell and Sky, not exactly the 6ND430 but the 10NDA520 at:
http://www.diyaudio.com/forums/showthread.php?postid=1197093#post1197093
"http://www.diyaudio.com/forums/showthread.php?postid=1197093#post1197093"
Along this thread many speakers were discussed and I also proposed the Mundorf AMT's. It might be interresting to have a first hand experiance or some measurements from your last project?
May be you can post some pictures there?
Greetings
Michael
Hi
Hell and Sky, you may also have a look at this thread:
http://www.diyaudio.com/forums/showthread.php?postid=1190355#post1190355
"http://www.diyaudio.com/forums/showthread.php?postid=1190355#post1190355"
Greetings
Michael
Hell and Sky, you may also have a look at this thread:
http://www.diyaudio.com/forums/showthread.php?postid=1190355#post1190355
"http://www.diyaudio.com/forums/showthread.php?postid=1190355#post1190355"
Greetings
Michael
mige0 said:
Pretty much. 250Hz 2nd and 1600Hz 4th order Linkwitz-Riley at the moment and I got the balance fixed pretty nicely. Flat measured on axis response isn't good since system is that constant directive as it is. But adding some lowmid range and drop some from the tweeter fixes the problem.
I haven't got that much done recently. Just listened. Config needs the spine, some paint, cloth and final build.
Jussi
Ok. Pretty extensive listening and tweaking. Propably not 100% happy but close. Few aspects of the design and basic design principles...
First of all my panels aren't permanately build yet which causes some problems with recordings that have lots of bass and/or low midrange. Rattling. Therefore I can't judge bass / low midrange performance 100%. So far it's been very good and I'm very pleased with it. This is propably one main reason why they still are unbuild.
Actual bass, below 100Hz, is pretty shy. Or perhaps not shy but running certain recordings at appropriate levels would need more grunt to achieve that last jaw dropping effect.
This is why I'm considering to add something to the bass department later. Either single or stereo monopoles or stereo dipolesubs have crossed my mind. More displacement.
Bass quality is very good considering the rather horrible acoustic environment (also one thing to improve). Fast, detailed and still laid back, doesn't draw any attension. It's just there. Just the way I want it. This is why I don't want to make and fast conclusions about the woofer arragement. I need to get things better, not just louder.
Dynamics work very well. Startling even. System plays even demanding orchestral samples with ease and overally sound with any dynamic recording is easy and effortless. Spacious and open soundstage propably improves this effect.
On the other hand system is pretty merciful to poorer recordings. Naturally differences are audible but system doesn't sqeeze guts out and put them on display. This is also one feature I like. Naturally high resolution might be the term here.
Of cource things match best at sweetspot but overally these work very well pretty much anywhere. I might play some backround music while cooking in the kitchen and the sound is pleasant and enjoyable. Not that boom boom effect to other rooms that some monopole solution in poorer acoustics often offer. In the livingroom I can listen pretty much anywhere I like. Absolute resolution and imaging isn't 100% out of the sweetspot but sound is still very enjoyable and natural. Measurements actually back this up. I measured 45 degree horizontal response and got +-2dB flat response 100-10000Hz. So the speaker itself sounds way off axis very similar that it does in sweetspot. Just 2-3dB lower level.
So. I need the bass. And I'm also considering rear tweeters. One friend of mine visited for audition and mensioned about the issue. I think speakers sound open and spacious at lowmid and uppermid ranges while tweeter ranges radiation pattern is just a normal waveguided cardioid. No rear radiation there. This might enhance absolute accuracy but it also causes a little discontinuous behavior in imaging. If something is mixed to far right or far left and is played with dipole drivers sound seems to come way further away and a bit more fuzzy and perhaps naturally openly compared to tones played by the tweeter which focus things more sharply. So I think this is a compromisse between absolute accuracy and "natural" pleasent imaging. I need to experiment...
Jussi
First of all my panels aren't permanately build yet which causes some problems with recordings that have lots of bass and/or low midrange. Rattling. Therefore I can't judge bass / low midrange performance 100%. So far it's been very good and I'm very pleased with it. This is propably one main reason why they still are unbuild.
Actual bass, below 100Hz, is pretty shy. Or perhaps not shy but running certain recordings at appropriate levels would need more grunt to achieve that last jaw dropping effect.
This is why I'm considering to add something to the bass department later. Either single or stereo monopoles or stereo dipolesubs have crossed my mind. More displacement.
Bass quality is very good considering the rather horrible acoustic environment (also one thing to improve). Fast, detailed and still laid back, doesn't draw any attension. It's just there. Just the way I want it. This is why I don't want to make and fast conclusions about the woofer arragement. I need to get things better, not just louder.
Dynamics work very well. Startling even. System plays even demanding orchestral samples with ease and overally sound with any dynamic recording is easy and effortless. Spacious and open soundstage propably improves this effect.
On the other hand system is pretty merciful to poorer recordings. Naturally differences are audible but system doesn't sqeeze guts out and put them on display. This is also one feature I like. Naturally high resolution might be the term here.
Of cource things match best at sweetspot but overally these work very well pretty much anywhere. I might play some backround music while cooking in the kitchen and the sound is pleasant and enjoyable. Not that boom boom effect to other rooms that some monopole solution in poorer acoustics often offer. In the livingroom I can listen pretty much anywhere I like. Absolute resolution and imaging isn't 100% out of the sweetspot but sound is still very enjoyable and natural. Measurements actually back this up. I measured 45 degree horizontal response and got +-2dB flat response 100-10000Hz. So the speaker itself sounds way off axis very similar that it does in sweetspot. Just 2-3dB lower level.
So. I need the bass. And I'm also considering rear tweeters. One friend of mine visited for audition and mensioned about the issue. I think speakers sound open and spacious at lowmid and uppermid ranges while tweeter ranges radiation pattern is just a normal waveguided cardioid. No rear radiation there. This might enhance absolute accuracy but it also causes a little discontinuous behavior in imaging. If something is mixed to far right or far left and is played with dipole drivers sound seems to come way further away and a bit more fuzzy and perhaps naturally openly compared to tones played by the tweeter which focus things more sharply. So I think this is a compromisse between absolute accuracy and "natural" pleasent imaging. I need to experiment...
Jussi
By the way, what would you recommend for the bass department?
Single/stereo monopoles or physically larger dipolesubs?
Can dipolewoofers, no mather how much displacement and raw power they deliver, give that final sharp punch in the chest or is it 100% monopole stuff?
I tried one commercial 12" closed subwoofer in the setup but unfortunately I didn't have enough equipment to get it even nearly 100% adjusted. So I don't know was the audible problem with it caused by configs overall operating principle or was it just messed up other vice.
At least dipoles leave <30Hz pretty much shy no mather how large they are while they can have higher crossoverpoint at top end (80-100Hz). Large monopole on the other hand can deliver plenty of output down to 15Hz or so in this room.
Jussi
Single/stereo monopoles or physically larger dipolesubs?
Can dipolewoofers, no mather how much displacement and raw power they deliver, give that final sharp punch in the chest or is it 100% monopole stuff?
I tried one commercial 12" closed subwoofer in the setup but unfortunately I didn't have enough equipment to get it even nearly 100% adjusted. So I don't know was the audible problem with it caused by configs overall operating principle or was it just messed up other vice.
At least dipoles leave <30Hz pretty much shy no mather how large they are while they can have higher crossoverpoint at top end (80-100Hz). Large monopole on the other hand can deliver plenty of output down to 15Hz or so in this room.
Jussi
What were the SPL requirements for your bass (30-100)?
I believe the issues you are bringing up are simply SPL related.
Just from the dipole SPL calculator, an H-frame with two 805 cm^2 drivers on each side (15 inch) and 14 mm of xmax, the output is 100 db for one speaker at 35 hz. (Also add 6 db for 2 pi space for a total of 106 db). The driver for this recommended setup is the Dayton 15" Hi fi series.
Add monopole woofer below this hidden in a corner and you're set.
Options
-You could also use smaller drivers and cross to the monopoles higher.
-For space, you could also use U-baffles, for more output or less size.
-Go full monopole, build several, use experimental digital room correction algorithms for high SPL while still managing room effects
At least with a set of good drivers, its easy to experiment with what you like. Monopole or dipole subwoofer boxes are easy to prototype. Tackle the next important bandwidth range (35-100hz) before worrying about the rest.
I believe the issues you are bringing up are simply SPL related.
Just from the dipole SPL calculator, an H-frame with two 805 cm^2 drivers on each side (15 inch) and 14 mm of xmax, the output is 100 db for one speaker at 35 hz. (Also add 6 db for 2 pi space for a total of 106 db). The driver for this recommended setup is the Dayton 15" Hi fi series.
Add monopole woofer below this hidden in a corner and you're set.
Options
-You could also use smaller drivers and cross to the monopoles higher.
-For space, you could also use U-baffles, for more output or less size.
-Go full monopole, build several, use experimental digital room correction algorithms for high SPL while still managing room effects
At least with a set of good drivers, its easy to experiment with what you like. Monopole or dipole subwoofer boxes are easy to prototype. Tackle the next important bandwidth range (35-100hz) before worrying about the rest.
Hi
Jussi, that sounds good - lots of pro's on your list!
The problem with lowest bass notes seems to be inherent to the OB concept. Can you make a simple 1/3 octave RTA pink noise measurement at the listening place and post it?
A possible solution was proposed by a German DIY magazine.
They propose to place a W-style dipole sub
http://www.lautsprechershop.de/hifi/disub18_2_en.htm
"http://www.lautsprechershop.de/hifi/disub18_2_en.htm"
close to the wall and align the axis of the dipole in PARALLEL to the wall.
Measurements they published claim a more or less linear FR down to 20-25 Hz this way, whereas with the axis facing the wall - like with your OB woofer and most others – show a severe dropping slope below 80 Hz or so. Unfortunately the measurements itself are not available on the web.
This is something I saw as a big hurdle right from the beginning. To combine steel and MDF isn't that easy I guess. How exactly did you build the sandwich? Did you glue or screw or put some elastics in between? Are the speakers attached to the steel or to the MDF?
Greetings
Michael
Jussi, that sounds good - lots of pro's on your list!
The problem with lowest bass notes seems to be inherent to the OB concept. Can you make a simple 1/3 octave RTA pink noise measurement at the listening place and post it?
A possible solution was proposed by a German DIY magazine.
They propose to place a W-style dipole sub
http://www.lautsprechershop.de/hifi/disub18_2_en.htm
"http://www.lautsprechershop.de/hifi/disub18_2_en.htm"
close to the wall and align the axis of the dipole in PARALLEL to the wall.
Measurements they published claim a more or less linear FR down to 20-25 Hz this way, whereas with the axis facing the wall - like with your OB woofer and most others – show a severe dropping slope below 80 Hz or so. Unfortunately the measurements itself are not available on the web.
This is something I saw as a big hurdle right from the beginning. To combine steel and MDF isn't that easy I guess. How exactly did you build the sandwich? Did you glue or screw or put some elastics in between? Are the speakers attached to the steel or to the MDF?
Greetings
Michael
Michael, you say the HHF review suggests placing this not out 2m into the room between the speakers, but against the side wall? With the backside (where the amp is mounted) up against the wall correct?
Interesting.
cheers,
AJ
Hara said:
As a raw number? I don't know. I've played maybe 95-98dB so far according to my cellphone SPL meter. I don't know how accurate it is. But the reading is well inline with expected efficiency and consumed power.
This is very possible.
Unfortunately I don't have space for both solutions. So it's monopole(s) below mains 2x10" dipoles or separated dipolecolumns in Beethoven style.
Personally I'd settle for ~30Hz extension if I get fully functional. After all there isn't that much material below that point and having a uniform packadge down to there is plenty of challenge.
mige0 said:
Thanks.
Here is a roomresponse using 300ms window and 1/6th octave smoothing. Basically the only real problem frequency is that 33Hz centered lowest listening direction mode in this room. So far it hasn't been that big problem since I can notch it off in my Behringer. Same mode is also dominant with monopole subwoofer.
Actually this response isn't one of the latest ones since I've altered lowmid level since then but it overally shows how things work out.
I didn't quite got this one. On axis facing the wall? I guess it has to in some point. There is no infinite deep room to dispose. Presently my panels are 60cm from the sidewalls and pretty nice 150cm from the front. Toed in towards the listener.
Parallel to the wall, you mean along the sidewall? A bit like Linkwitz recommends his Phoenix woofers and AA Beethovens woofers to position? This still leaves them approx 150cm from the frontwall while they gain 6dB from the sidewall.
Like I said the panels aren't fully build yet. The woodpanels and the steel aren't connected to one another. So the constrained layer damping I'm after is propably working just the opposite at the moment. But the driverconfiguration causes pretty solid fastening when I stack them together so I want to be sure I don't need to make any changes before I do it. After that the whole packadge has to be ripped apart if some driver needs to be removed.
Jussi
Attachments
No, NOT with the backside against the wall, but with the cone plane parallel to the wall. Placing it along the side wall is just an option, front wall would be fine too. Placement should keep the dipole null plane from going through the listening position. Obviously this will work best for mono implementations.
The measurements showing a severe dropping slope below 80 Hz were made with the backside (where the amp is mounted) up against the wall - results as were to be expected.
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