Jussi,
Genelec uses waveguided tweeters in their monitors AFAIK, they are Finnish aren't they? You might be able to check them out on location. These monitors go to up to 120 dB, if you are able to get what they got, it might fit the bill.
Augerpro,
I did not try removing the grill because I thought the tweeters were designed with the grill in mind. I don't have any sources on measurements without the grill or on how to remove the grill (although I haven't searched) and without knowing how it will respond makes it discouraging for me to try it out if restoring the grill to its previous state would be difficult.
I did not try removing the grill because I thought the tweeters were designed with the grill in mind. I don't have any sources on measurements without the grill or on how to remove the grill (although I haven't searched) and without knowing how it will respond makes it discouraging for me to try it out if restoring the grill to its previous state would be difficult.
MBK said:
That's correct. I've heard most of their selection. Up to the large 1036A main monitors. Genelec factory is about 80km north from my home. In their 8000 monitor series they use Vifa and Seas aluminiums. Seas 25mm in the biggest 8050 and 19mm Vifa for the rest.
From 8000 serie biggest 8050 is the only one referring to >120dB max output. It uses 8" PP cone midwoofer and 25mm Seas aluminium, crossed 1800Hz 4th order. 120dB means peak SPL in half space with two speakers at 1m distance. This makes 108dB with a single speaker to full space. Respectable number but nothing unique. Not that I'd need more SPL and I think the 27mm new Seas models are very good.
Genelec waveguides are made considering the radiation pattern. You can check those out from individual models specsheets last page. For max output guide would have to be steeper and that way more directive but it doesn't serve its purpose in radiation control anymore.
Personally I'd like that grid on a dome. Keeps the dome safe. Normal problem to anyone that has small children running around. But only from fingers. Dome can still eat icecream and drink lemonade. 😀
Jussi
Hara said:
Here is a short thread:http://www.htguide.com/forum/showthread.php4?t=22214
There is more info interspersed in other threads you should look at also. I think it's worth a try to remove the grid and listen&measure.
Augerpro,
Thanks for the link. My concern is also for the loss of functionality of the phase shield. On this website http://www.speakerdesign.net/dayton_rs/midrange/rs52/dayton_rs52.html there is a section on the theory behind the phase shield. Phase shields tend to be important for domes made of stiff materials like metal.
If I get the hifitalo waveguides, my main concern will be to properly mount it to the tweeter without any alignment, offset, or stored energy problems.
Thanks for the link. My concern is also for the loss of functionality of the phase shield. On this website http://www.speakerdesign.net/dayton_rs/midrange/rs52/dayton_rs52.html there is a section on the theory behind the phase shield. Phase shields tend to be important for domes made of stiff materials like metal.
If I get the hifitalo waveguides, my main concern will be to properly mount it to the tweeter without any alignment, offset, or stored energy problems.
Interesting. Well, I personnally use Seas 27 TBFCG with the grid, crossed to a 6.5" PP Scanspeak woofer, at 1750 Hz LR4! ... funny how one comes to end up in similar quarters sometimes, I had no idea of the details of the Genelecs, I only checked them out casually at some point in time.
I wanted to build a waveguide initially, but the radiation pattern of the 6.5" up to 2k is so close to omni, at least in front, very little falloff, that I am not sure if it's worth it. The 6.5" have an off axis dip around 1.5k but dispersion picks up at 2k again before going into the abyss.
W/o waveguide I lose the gain in output at the low end of course, so the 1.8k XO is the absolute limit, and yes, I calculated around 100 dB max from the tweeter at crossover point which fits your Genelec numbers considering the absence of waveguide.
With real music I tested out yesterday (Nusrat Fateh Ali Khan, Mustt Mustt, alto baritone with bass guitar and drums), 100 dB average at 3 m from the speakers, stereo, C weighted on my SPL meter, is the absolute limit before sounding nasty. 95-96 dB is the safer limit. I suspect the tweeter gives up first, but it may be clipping as well. Anyway this kind of SPL is very reasonable for a home system, so I can vouch for the resilience of the TBFCG. It sounds exceptionnally clean as well. And it's cheap too. Nevermind if you wreck one in an experiment...
Hara said:
Alignment and offset. You mean the problem that driver is further away from the listener? It's actually one advantage. Is closer to midranges acoustic center so there is not that much need for delays in the crossover.
From the whole systems view guide reduces stored energy problems since diffraction problems reduce significantly. Check out mensioned Genelec models: www.genelec.com. New 8000 serie monitors have pretty smooth curves, both on and off axis. New diffraction optimized aluminium cabinet works nicely.
MBK said:
Have you measured off axis? If you have a standard box speaker (as I understood) you can estimate your power response by measuring 60 degrees horizontal off axis response. It gives pretty good clue about it.
Yep. Actually many professional manufacturers have very reasonable and measured specs. Pretty unusual in normal home systems. Some manufacturers specs don't make any sense.
100dB average? I don't think I'll be listening that loud. Maybe 85dB average, dynamic peaks might go way over 100dB with dynamic material.
Quality and price don't go hand in hand everytime. 🙂
Jussi
Hi Jon
This is away from the current direction of this thread: have you covered your latest thinking on optimal flat baffle shape and driver positioning in an earlier thread?
Thanks
I was just for test purposes! 😀 At best I'll use these levels at parties. Besides, wife and kid prevent any abuse of SPL But, one has to make sure things perform to spec, no? 😱
Yes, I have, though in a primitive in-room setup with likely reflection artefacts, and a bit closer than I wish (1.2 m). But hey, it's an indication. I have a largish dipole 3-way with shallow (20 cm) U-frame, ca. 120x60cm. I often have had similar thoughts as yours here actually, but to everyone his own trade offs.
I posted the off-axis response somewhere but it might have been in another thread, so here it is again.
Attachments
MBK said:
Oh, sorry. I misunderstood. With steep crossover at 1750Hz 1" Seas dome should handle 110dB within its linear excursion. But this doesn't mean it sounds good at those levels. Is your system passive or active? Passive network and low(ish) overall efficiency might run juice out of your amp like you mensioned while tweeter could still play well. But above 100dB levels with 90dB or so efficienct tweeter starts to cause thermical problems. This is why I like the efficiency. Esotar in waveguide is about 96dB up to 7Khz then dropping to specs 92dB while waveguides effect run out.
Scale is a bit off. It doesn't show that much. Looks like it should have response up to 180 degrees off axis but they are all in the same bunch. But with a front firing tweeter only 180 degrees response should be down quite a bit.
Jussi
Sorry if this is the wrong place to ask the question but I figured some of you would know how to do this.
I emailed hifitalo.fi and gave address and product quantity. They returned the exact price in euros and gave me their bank number. How do I send them the money? 😕
I asked if they used paypal and they did not answer the question.
I emailed hifitalo.fi and gave address and product quantity. They returned the exact price in euros and gave me their bank number. How do I send them the money? 😕
I asked if they used paypal and they did not answer the question.
My system is allactive, no passive components at all. I have the Diyaudio generated MOX variable analog crossover, with a lot of patches for additional filters though, definitely not a permanent setup. But it plays...
The graph is too busy but I only made this one... I didn't bother improving it because it has the in-room limitation which makes it marginal anyway. I have to drag the system into the yard at 3 am when traffic is low to improve that.
But what it does show is this: all the curves are within a 6 dB bracket, and above 400 Hz or so, there is no clear dipole falloff. And the 180 is not a misprint, I did a full (half) circle. I am mystified about the tweeter as well. My only explanation is that a) baffle edges will diffract HF (and so start a new point source) and b) the tweeter is very close to the top of the baffle. I did this intentionnally, to allow for rear radiation as well (to make the baffle step effect insignificant for the top edge). I just never imagined it would work that well.
The grid lines are 3 dB apart, so I expected the 45 and 60 degree lines to nocely be distinguishable, but not so. There are some wiggles at all angles, but they overlap.
The only larger, consistent deviation in dispersion is at 180 degrees at 1.5-1.8k. Since in this range the rear wave of the woofer must be out of phase with the rear-dispersed front wave of the tweeter, and since this is where the crossover falls, it is effectively a reverse null. So, this deviation gives me confidence that the measurement is not all artefact. But I can't quite explain why the dispersion should be so uniformly even, especially at the rear.
Last note, the subjective effect is consistent with the graph as well. Walking towards the speaker, the soundstage only collapses when I reach the line between the speakers. At the rear, sound is somewhat duller but not excessively so unlkess in the imediate shadow (say at 50 cm). At all reasonable front angles, the timbre does remain reasonably equal. Only at a larger distance at exactly 90 degrees does one notice the leaner bass (below 400 Hz true dipole behavior sets in).
The graph is too busy but I only made this one... I didn't bother improving it because it has the in-room limitation which makes it marginal anyway. I have to drag the system into the yard at 3 am when traffic is low to improve that.
But what it does show is this: all the curves are within a 6 dB bracket, and above 400 Hz or so, there is no clear dipole falloff. And the 180 is not a misprint, I did a full (half) circle. I am mystified about the tweeter as well. My only explanation is that a) baffle edges will diffract HF (and so start a new point source) and b) the tweeter is very close to the top of the baffle. I did this intentionnally, to allow for rear radiation as well (to make the baffle step effect insignificant for the top edge). I just never imagined it would work that well.
The grid lines are 3 dB apart, so I expected the 45 and 60 degree lines to nocely be distinguishable, but not so. There are some wiggles at all angles, but they overlap.
The only larger, consistent deviation in dispersion is at 180 degrees at 1.5-1.8k. Since in this range the rear wave of the woofer must be out of phase with the rear-dispersed front wave of the tweeter, and since this is where the crossover falls, it is effectively a reverse null. So, this deviation gives me confidence that the measurement is not all artefact. But I can't quite explain why the dispersion should be so uniformly even, especially at the rear.
Last note, the subjective effect is consistent with the graph as well. Walking towards the speaker, the soundstage only collapses when I reach the line between the speakers. At the rear, sound is somewhat duller but not excessively so unlkess in the imediate shadow (say at 50 cm). At all reasonable front angles, the timbre does remain reasonably equal. Only at a larger distance at exactly 90 degrees does one notice the leaner bass (below 400 Hz true dipole behavior sets in).
Hara said:
I don't know their policy on international sales. Normal policy is to pay the order before delivery. With more expensive investments it's possible to pay at delivery but these only in Finland.
Normally they have answered. Have you considered time-lag between you and Finland? They are open 5pm or 6pm local time.
Jussi
Hifitalo dont use paypal because it is not worldwide or even European wide internet salescompany.Its only Finnish hobbyist's as far as i know.
I think you should go to your own bank who takes care for your money transfer into Hifitalos account.Or alternatively use bank in net.
If you do money transfer by yourself you should notice daily exchange rate.
Like 100usd is about 80euros.
But ask your bank.
Member
Joined 2003
They gave you their bank number so you can electronically transfer funds from your bank to theirs. Contact your bank to do this.
I've had good results using "escrow.com" for international transactions. Cost for escrow service is roughly the same as a bank transfer, but with a little more security than sending cash equivalent.
What do you guys think about this rear tweeter issue?
Basically my construction doesn't support rear tweeter but it's possible to add them if necessary. Similar "dipolar" behavior as in Orions or NaOs case isn't propably expected since waveguides allready point the sound to front and back having 12-13dB directivity to 90 degrees off axis.
But would rear radiation have some positive influence on overall performance? Even that theoretical 1-2dB power response roll off would fade away and whole system would radiate pretty nicely the same amount up to 8Khz or so. Which is propably too high making the system too bright but that can be fixed by nodding the on axis response.
Still waiting results from my Esotars. This rear tweeter issue is a closed case if those Esotars are fixed and I'll use them in my project. I can't use two Esotars in same speaker (too large and expensive drivers) and I can't think of that similar replacement to use in the rear.
Jussi
Basically my construction doesn't support rear tweeter but it's possible to add them if necessary. Similar "dipolar" behavior as in Orions or NaOs case isn't propably expected since waveguides allready point the sound to front and back having 12-13dB directivity to 90 degrees off axis.
But would rear radiation have some positive influence on overall performance? Even that theoretical 1-2dB power response roll off would fade away and whole system would radiate pretty nicely the same amount up to 8Khz or so. Which is propably too high making the system too bright but that can be fixed by nodding the on axis response.
Still waiting results from my Esotars. This rear tweeter issue is a closed case if those Esotars are fixed and I'll use them in my project. I can't use two Esotars in same speaker (too large and expensive drivers) and I can't think of that similar replacement to use in the rear.
Jussi
Member
Joined 2003
My view is "maybe". In other words, there is no clear-cut answer. Things to consider include distance to the front wall, whether the listener prefers precise imaging or more diffuse sound field, SACD/DVD-A multi-channel or two-channel stereo.
For the past few years I have had at least philosophical issue with dipoles that made "hard" transition to monopole above crossover...it just doesn't make sense from either power response or soundfield viewpoint. (Maybe you remember I asked what you were planning to do earlier in this thread.)
Personally, I prefer more precise imaging, but most of my serious listening is now multi-channel. (Standard CD production quality is so erratic I refuse to buy them.) Multi-channel can provide "space" but still allows speakers that image well. I once discussed imaging with a person who liked omni-directional speakers and I wondered about my own sanity...then I realized he was talking about stereo and I was talking about multi-channel, so we were comparing apples and oranges!
My room limits speaker distance to the front wall to about 1.5 meters. Since I prefer more precise imaging, I slowly roll off upper midrange rear radiation with absorbent felt across the back of the drivers. Not perfect from a power response perspective, but at least the transition is very gradual rather than abrupt...plus it preserves strong imaging with relatively close front wall.
If I ever have the opportunity to place main speakers 2-3 meters into the room, I will try equal front-rear radiation. Heck, at 3 meters, I might even try omni 🙂
Ha. So I am not alone in scratching my head. I often spend days fixing my broken system before realizing, this "sound" actually came straight from the CD in true fidelity.
Anyways... to the subject: I tried it, unlike Paul I have undamped rear baffles and yes, I am also philosophically uncomfortable with the issue. But same here, at 1.2 m from the front wall the rear tweeters stayed in for a week or so, they were sort of interesting to listen to, but ultimately confused the sound more than they helped. One might have improved on that with fine tuning of levels, placement etc, but basically it was not a massive revelation to me.
In other words, don't sweat it, you'll be fine for a couple years before you break down and start tweaking again. You might (if you still can) narrow the baffle at the tweeter's location to allow more radiation to diffract to the rear. My tweeter sits on top end of the baffle, and ends up radiating quite a bit to the rear as you might recall from the off axis measurements I posted here. I since repeated the measurements with greater distance to the walls , now the falloff seems greater (less room reflection influence in the data) but the overall message is similar - the power response does not appear to suffer too much. Interestingly what IS noticeable in my system at least, is the bass falloff at 90 degrees - but not any lack of treble.
Thanks for the input. I think ambience and diffusion can be done better than using rear radiating tweeter. At least when it comes to soundstage effect.
Finnish audio pioneer Tapio Köykkä introduced his ortoperspect configuration in the 70's. Here is a basic setup compared to normal stereo:
http://www.kolumbus.fi/epap/voimaradio/ortoperspekta/ortoperspekta2.html
Sorry that I didn't find english article about it. At the left is the overall soundfield in live concert. Straight sound comes from front and reflections from sidewalls and other boundaries from the sides creating soundstage for the performance. At the right is the normal stereosetup. It just can't play those ambience sounds since all the sound is coming from the front and along with the direct sound.
Here is the ortoperspect view:
http://www.kolumbus.fi/epap/voimaradio/ortoperspekta/ortoperspekta4.html
It uses single center speaker that plays all direct sound. Basically a mono speaker playing right + left channels. And then there are two speakers at the sides playing diffuse sound. This is achieved by connecting diffuse speakers like this:
http://www.kolumbus.fi/epap/voimaradio/ortoperspekta/ortoperspekta6.html
So sidespeakers play channels left minus right and right minus left which only contains space information of the acoustic performance.
I have once heard such a system. It used stereospeakers with single diffuse speaker. With correct material it worked out very good. Walls truely disappear and a very realistic soundstage forms at front of you. But there are flipsides. This requires very certain kind of acoustic material to play with. Standard studiostuff is mixed and therefore pretty much total disaster in a system like this. It just throws instruments all over the place. But like mensioned good soundstage and imaging already require HQ acoustic material.
The system I heard used pretty constant directivity 3-ways for main channels and a small dipole speaker for the diffuse. Dipole was placed at the front and listener is at 90 degree off axis angle against it. So not that much direct sound from that towards the listener. Diffuce reflections from sidewalls create that wall disappearing act.
I think Linkwitz is going towards something like this. He already used straight connected mains with Lexicon Logic 7 ambience system in his multichannel tests and now introduced rear tweeters for the Orions.
With the recommended single main speaker setup configuration isn't that usable with most recorgings (studiostuff) and thr ambience speaker should also have level adjustment and muting possibility. Propably even remote controlled so correct amount of ambience is easy to adjust from listening position.
Orto is one configuration I attend to experiment in the future. That session with the system mensioned opened my eyes in the mather. I have both digital and analog outputs in my present CD player. Analog outputs have remote controlled level adjustment while digital output goes flat. Therefore I could explore it's potential by using digital output and some external DAC to mains and then add single or two ambience speakers connected to analog outputs. Then I can adjust ambience level from complete mute to mains level. Two ambience speakers placed to listening positions sides could also serve as surround speakers for multichannel setup.
Jussi
Finnish audio pioneer Tapio Köykkä introduced his ortoperspect configuration in the 70's. Here is a basic setup compared to normal stereo:
http://www.kolumbus.fi/epap/voimaradio/ortoperspekta/ortoperspekta2.html
Sorry that I didn't find english article about it. At the left is the overall soundfield in live concert. Straight sound comes from front and reflections from sidewalls and other boundaries from the sides creating soundstage for the performance. At the right is the normal stereosetup. It just can't play those ambience sounds since all the sound is coming from the front and along with the direct sound.
Here is the ortoperspect view:
http://www.kolumbus.fi/epap/voimaradio/ortoperspekta/ortoperspekta4.html
It uses single center speaker that plays all direct sound. Basically a mono speaker playing right + left channels. And then there are two speakers at the sides playing diffuse sound. This is achieved by connecting diffuse speakers like this:
http://www.kolumbus.fi/epap/voimaradio/ortoperspekta/ortoperspekta6.html
So sidespeakers play channels left minus right and right minus left which only contains space information of the acoustic performance.
I have once heard such a system. It used stereospeakers with single diffuse speaker. With correct material it worked out very good. Walls truely disappear and a very realistic soundstage forms at front of you. But there are flipsides. This requires very certain kind of acoustic material to play with. Standard studiostuff is mixed and therefore pretty much total disaster in a system like this. It just throws instruments all over the place. But like mensioned good soundstage and imaging already require HQ acoustic material.
The system I heard used pretty constant directivity 3-ways for main channels and a small dipole speaker for the diffuse. Dipole was placed at the front and listener is at 90 degree off axis angle against it. So not that much direct sound from that towards the listener. Diffuce reflections from sidewalls create that wall disappearing act.
I think Linkwitz is going towards something like this. He already used straight connected mains with Lexicon Logic 7 ambience system in his multichannel tests and now introduced rear tweeters for the Orions.
With the recommended single main speaker setup configuration isn't that usable with most recorgings (studiostuff) and thr ambience speaker should also have level adjustment and muting possibility. Propably even remote controlled so correct amount of ambience is easy to adjust from listening position.
Orto is one configuration I attend to experiment in the future. That session with the system mensioned opened my eyes in the mather. I have both digital and analog outputs in my present CD player. Analog outputs have remote controlled level adjustment while digital output goes flat. Therefore I could explore it's potential by using digital output and some external DAC to mains and then add single or two ambience speakers connected to analog outputs. Then I can adjust ambience level from complete mute to mains level. Two ambience speakers placed to listening positions sides could also serve as surround speakers for multichannel setup.
Jussi
This is really funny. I had been thinking of that kind of experiment, but of course, nothing new under the sun, already been done. I think it makes complete sense to have stereo or multichannel organized this way. It always annoys me when singers or main instruments are panned off center or illogically. And the most anti-intuitive artefact of classic stereo is this: in normal life, if a sound seems to come from, say, the rght side, and you walk to the left side, the sound becomes softer, and even more to the right. In stereo reproduction, in this situation, you'd be walking towards the left speaker, thusly, the previously right-panned sound now becomes louder and soon seems to be coming from the *left*.
- Status
- Not open for further replies.