A little wake-up call here.
I've been too busy fiddling with the speaker's EQ, XO and tonal balance, as well as just listening to music.
On-axis, it measures flat from 25 Hz and up. That's easy to do with enough EQ.... I havn't been able to do proper off-axis measurements yet. The measurements have to be done outdoors I think, because I get too much reflections indoors. What is quite obvious is the bass. There is almost no bass at all at 90 degree angle. Experimental measurements show that there is about 20 dB less output sideways than front/rear, but not at 90 degree angle - a bit more than 90 degrees actually. This is because of the wings I guess.
I've made a few changes to the XO. I cross over at 300 and 1550 Hz, this sounds best to my ears. 300 Hz with a 21" woofer might scare the most of you, but it works very well indeed. The main reason for crossing at 300 Hz is that the midrange response drops off quite a lot below 300.
Listening:
I understand why people say OB bass is the best. It *IS* the best. Period. I've never heard any better. The same goes for the mid and treble too. The Beyma TPL-150 is a wild beast to tame, but if you manage to get it right, there may be nothing better.
This dipole speaker presents the stereo image in a different way than all other speakers I've heard in my listening room. It difficult to describe, but I'll try... Voices appear more natural in the stereo image I think. On pop/rock recordings vocals are often processed very hard, making them stand out in the mix, and appear "in your face". These speakers dont do that, but not at all any less detailed or defined, rather more detailed than other speakers I've heard. There is also more spaciousness on good classical recordings, easier to hear when singers move around the microphones and such details.
The most important part however is that these speakers add less "grain" or "speaker signature" to the sound. A lot of speakers have their own signature, which is added to everything - these have less of that I think. They make different recordings sound a lot more different than anything else I've heard.
(I hope you understand what I'm trying to say, and excuse my less that great English.....)
I've been too busy fiddling with the speaker's EQ, XO and tonal balance, as well as just listening to music.
On-axis, it measures flat from 25 Hz and up. That's easy to do with enough EQ.... I havn't been able to do proper off-axis measurements yet. The measurements have to be done outdoors I think, because I get too much reflections indoors. What is quite obvious is the bass. There is almost no bass at all at 90 degree angle. Experimental measurements show that there is about 20 dB less output sideways than front/rear, but not at 90 degree angle - a bit more than 90 degrees actually. This is because of the wings I guess.
I've made a few changes to the XO. I cross over at 300 and 1550 Hz, this sounds best to my ears. 300 Hz with a 21" woofer might scare the most of you, but it works very well indeed. The main reason for crossing at 300 Hz is that the midrange response drops off quite a lot below 300.
Listening:
I understand why people say OB bass is the best. It *IS* the best. Period. I've never heard any better. The same goes for the mid and treble too. The Beyma TPL-150 is a wild beast to tame, but if you manage to get it right, there may be nothing better.
This dipole speaker presents the stereo image in a different way than all other speakers I've heard in my listening room. It difficult to describe, but I'll try... Voices appear more natural in the stereo image I think. On pop/rock recordings vocals are often processed very hard, making them stand out in the mix, and appear "in your face". These speakers dont do that, but not at all any less detailed or defined, rather more detailed than other speakers I've heard. There is also more spaciousness on good classical recordings, easier to hear when singers move around the microphones and such details.
The most important part however is that these speakers add less "grain" or "speaker signature" to the sound. A lot of speakers have their own signature, which is added to everything - these have less of that I think. They make different recordings sound a lot more different than anything else I've heard.
(I hope you understand what I'm trying to say, and excuse my less that great English.....)
StigErik said:
I totally agree. It requires equalization (but which bass IN ROOM doesnt need it?
). I felt the same when i finished my speakers... but then I heard better: more woofers in OB + subwoofers for the very low freqs (<40hz). All perfectly setup and equalized and time-aligned.For the highs, I also think that Heils are the best.
What's your take on the midrange that you use? I have been recommended anything from scan-speak to zelaton, passing through the banana tagband...
I mean, do you feel a smooth transition and comparable speed between the mids and the beymas?
OB's require EQ only because of their working principle: 6 dB baffle loss compensation and dipole peak compensation. Other bass solutions always require room response EQ, OB's do generally not.
With my large closed box towers there are lots of room EQ between 30 and 300 Hz to make them flat in the listening position. I found that this was not necessary at all with the dipoles.
I'm going to add closed box subwoofers to fill in below 30 Hz... maybe an other 21" woofer, but its not finally decided yet.
My take on the midrange is that the Seas W22 is among the best there is up to 1500 Hz. I understand why its Linkwitz' favourite midrange!
The transition between the drivers in my dipole sounds seamless to me, I dont hear any obvious problems here now.
That being said - I did have great problems with the Seas W22 when using other tweeters, like the Mundorf AMT2340 and Philips RSQ8P. I was never able to get those drivers to integrate well. That's why I added the 5-inch Seas to my large tower speaker to fill in between the W22 and the Mundorf AMT.
With my large closed box towers there are lots of room EQ between 30 and 300 Hz to make them flat in the listening position. I found that this was not necessary at all with the dipoles.
I'm going to add closed box subwoofers to fill in below 30 Hz... maybe an other 21" woofer, but its not finally decided yet.
My take on the midrange is that the Seas W22 is among the best there is up to 1500 Hz. I understand why its Linkwitz' favourite midrange!
The transition between the drivers in my dipole sounds seamless to me, I dont hear any obvious problems here now.
That being said - I did have great problems with the Seas W22 when using other tweeters, like the Mundorf AMT2340 and Philips RSQ8P. I was never able to get those drivers to integrate well. That's why I added the 5-inch Seas to my large tower speaker to fill in between the W22 and the Mundorf AMT.
God idea! I better get three pairs of 20 meter speaker cables first....
I do notch the 5 kHz peak. I also EQ the midrange flat up to 6 kHz because I use quite low XO slope. It's easier to get it flat around the XO frequency when the response is smooth at least an octave above XO, and it also sounds better.
I do notch the 5 kHz peak. I also EQ the midrange flat up to 6 kHz because I use quite low XO slope. It's easier to get it flat around the XO frequency when the response is smooth at least an octave above XO, and it also sounds better.
StigErik said:
Generally, yes
In my crazy room they required that, but nowhere as much as my closed boxes that were unlisteneable w/o EQ.
My take on the midrange is that the Seas W22 is among the best there is up to 1500 Hz. I understand why its Linkwitz' favourite midrange!
I think i heard it on some speakers very similar to yours and also inspired by Linkwitz. And i'm not sure if i like it or not... It sounded a bit different than other midranges. But for the better or for the worse I cannot say.
I'm planning on a third prototype. For this I will use some of the ideas suggested here. That being:
a) separate the bass and mid/tweeter baffle
b) add mass to the woofer baffle not only at the bottom, but all the way around to stabilize it.
Apart from that, there will not be many changes.
Current ideas is to make an MDF/concrete sandwich for the woofer baffle. This should make it very stiff, and increase the mass quite a lot. I will see if its possible to make the wings from 16 mm MDF, and use a 500 mm tube behind the driver, and then concrete between the two.
The mid/tweeter section will be as it is now, but improved with sand fillings and asphalt for damping. Will also try to improve the soft mounting of the drivers. The screw have contact with the drive frame, but if I drill larger holes in the frame this should be avoided, or use smaller diameter screws.
a) separate the bass and mid/tweeter baffle
b) add mass to the woofer baffle not only at the bottom, but all the way around to stabilize it.
Apart from that, there will not be many changes.
Current ideas is to make an MDF/concrete sandwich for the woofer baffle. This should make it very stiff, and increase the mass quite a lot. I will see if its possible to make the wings from 16 mm MDF, and use a 500 mm tube behind the driver, and then concrete between the two.
The mid/tweeter section will be as it is now, but improved with sand fillings and asphalt for damping. Will also try to improve the soft mounting of the drivers. The screw have contact with the drive frame, but if I drill larger holes in the frame this should be avoided, or use smaller diameter screws.
Time aligned baffles
I agree with CLS, if you want to go concrete then go concrete with bass baffles. Then it would be very interesting to see a full time alignment between bass, mid and treble-units because crossovers are just so in the critical areas. I have been urged to do so with my MJAO baffles by Ric Schultz: http://www.audiocircle.com/index.php?topic=65570.0 and http://www.audiocircle.com/index.php?topic=53821.100 and certainly I will just for the sake of seeing how differences are. There has been good arguments recently both here and over at the Audio Circle about time alignment in strive for perfection. So if you are spending a fortune on elements why not see to it that they will play optimally. And your baffle would be so easy to adapt.
/Erling
I agree with CLS, if you want to go concrete then go concrete with bass baffles. Then it would be very interesting to see a full time alignment between bass, mid and treble-units because crossovers are just so in the critical areas. I have been urged to do so with my MJAO baffles by Ric Schultz: http://www.audiocircle.com/index.php?topic=65570.0 and http://www.audiocircle.com/index.php?topic=53821.100 and certainly I will just for the sake of seeing how differences are. There has been good arguments recently both here and over at the Audio Circle about time alignment in strive for perfection. So if you are spending a fortune on elements why not see to it that they will play optimally. And your baffle would be so easy to adapt.
/Erling
Why use such big 21" woofer when subs still needed?
Its exstremely expencive(650EUR)
Surely there must be other candidates just as good, for this special restricted purpos
This SM118N can be found at 150EUR
http://www.beyma.de/fileadmin/seiten/download/pdf/Beyma_professional/SM118N.pdf
Its exstremely expencive(650EUR)
Surely there must be other candidates just as good, for this special restricted purpos
This SM118N can be found at 150EUR
http://www.beyma.de/fileadmin/seiten/download/pdf/Beyma_professional/SM118N.pdf
tinitus said:
Why the large woofer? I want to run the OB bass as low as possible, to maintain the OB bass quality down to at least 25-30 Hz. You cannot target 25-30 Hz with a single smaller woofer, simple as that. The "sub's" will only cover the 16-30 Hz range, and to be honest - such sub's are really not necessary.
Using multiple smaller (and cheaper) drivers have been discussed before in this thread.
And by the way... the 21" Beyma is not really that expensive I think. There are some that are willing to spend 10 times its price on more or less worthess items like speaker cables...... (No please, dont turn this into a cable discussion)
StigErik,
That won't work for dipole. I owe this argument to Rudolf and John Kreskovsky, but I can't fix the links at the moment because of Internet problems.
But it is intuitively clear. If you have elements aligned in the front, like on your baffle, what happens if you delay the signal of say the midrange with a time corresponding to 4" (=10 cm). The signal from the front of the speaker seem to come from a place 4" (10cm) back but signals emanating from the back of the speaker will seem to come from a place 4" (10 cm) in front of the original position, see !
So physical alignment is the only thing that will work for dipoles to have them perfect.
/Erling
That won't work for dipole. I owe this argument to Rudolf and John Kreskovsky, but I can't fix the links at the moment because of Internet problems.
But it is intuitively clear. If you have elements aligned in the front, like on your baffle, what happens if you delay the signal of say the midrange with a time corresponding to 4" (=10 cm). The signal from the front of the speaker seem to come from a place 4" (10cm) back but signals emanating from the back of the speaker will seem to come from a place 4" (10 cm) in front of the original position, see !
So physical alignment is the only thing that will work for dipoles to have them perfect.
/Erling
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