PBNAudio,
I have alawys thought your speakers looked impressive. I am sure they sound equally impressive.
I have alawys thought your speakers looked impressive. I am sure they sound equally impressive.
Bi-amped?
I'm also curious how did you time / phase align if it is passive network.
No not bi amped, ill see if I can find the XO schematic for this one and post it. Time alignment is actually pretty close as the horn moves the compression driver some backwards putting it more in line with the two woofers.
We made this speaker for a Concert at THE Show in Las Vegas in conjunction with the CES, we used it both in 2013 and 2014 at this event. In 2012 we made a similar speaker but this one was in a dual tapered TL and with 12" woofers. That one was likewise impressive, that was used for a concert with Paul Stooky, of Peter Paul and Mary.
I'm also curious how did you time / phase align if it is passive network.
No not bi amped, ill see if I can find the XO schematic for this one and post it. Time alignment is actually pretty close as the horn moves the compression driver some backwards putting it more in line with the two woofers.
We made this speaker for a Concert at THE Show in Las Vegas in conjunction with the CES, we used it both in 2013 and 2014 at this event. In 2012 we made a similar speaker but this one was in a dual tapered TL and with 12" woofers. That one was likewise impressive, that was used for a concert with Paul Stooky, of Peter Paul and Mary.
Heres a couple of pictures of the Daul 12" TL its a 25Hz line about 11.3 feet long
Good Listening
Peter
Good Listening
Peter
That "K2" looks very good. If they weren't almost unobtanium I would also like to try some 2235s.
Also this one here seems to be a nice woofer for such a Project:
http://www.beyma.com/getpdf.php?pid=15LW30
TSPs allow quite a low tuning (it can't compete with the 2235 in this respect of course), distortion is quite low and the FR is quite linear as well. Derek Wilson and Stig Erik Tangen mentioned it within another thread here.
Regards
Charles
Also this one here seems to be a nice woofer for such a Project:
http://www.beyma.com/getpdf.php?pid=15LW30
TSPs allow quite a low tuning (it can't compete with the 2235 in this respect of course), distortion is quite low and the FR is quite linear as well. Derek Wilson and Stig Erik Tangen mentioned it within another thread here.
Regards
Charles
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I have not seen what i would view as a condierable difference in many of the 15"woofers out there. This is, of course, based on whats on paper and what I read. In the context that we will be using them, they will rarely see more than a couple of watts, so distortion numbers at 100W are somewhat irrelevant. I am more concerned at their performance at 1W. I worry that the heavy duty coils that you will find on some of these options wil not sound good until they have a certain level of current being pushed through them. That is, after all, what they were designed for. That being said, the Beyma number do look good, having a realtively low Le, high BL, and low MMS, for a 15". Depending on what we hear, we may look at other options. I have ordered XO parts and we will audiotion this weekend, hopefully. Thankk for all the input. Keep it coming.
2235's have so so extension, with their main beneift being LF reproduction in a realtively small box.
2235's have so so extension, with their main beneift being LF reproduction in a realtively small box.
There are people saying that low mechanical losses (i.e. a high Qms) would be needed to get full bodied bass also at low listening volumes. Don't ask me what the reasoning is behind that. But there certainly are PA drivers available with low mechanical losses.
Something that I consider important - regarding the bass perception of such speakers - are the equal-loudness curves: A lot of speakers built with pro drivers don't go very low.
When driven at higher SPLs, Robinson-Dadson come to the rescue.
I have searched a little and found a test in the Voice Coil mag where Vance Dickason tested the bigger brother of the "B&C beast", i.e. the 18sw115. The linearity of this driver was exemplary, especially for exursions below +-5mm. He also measured THD with an amount of input power resulting in an average midrange level of 104dB. THD stayed below 1% almost everywhere. And that is definitely very good. But there is one downside: This driver has a breakup mode around 1300 Hz (estimation) causing a 3rd order THD peak somewhere between 400Hz and 500Hz. The 15 inch version with the same motor will most probably show the same behaviour (only slightly higher up in frequency due to the higher breakup point). Which is a pity because the otherwise excellent performance would make it an interesting woofer for a loud high quality speaker (Geddes uses another slightly less Beefy B&C driver in his Summa BTW).
Regards
Charles
Something that I consider important - regarding the bass perception of such speakers - are the equal-loudness curves: A lot of speakers built with pro drivers don't go very low.
When driven at higher SPLs, Robinson-Dadson come to the rescue.
I have searched a little and found a test in the Voice Coil mag where Vance Dickason tested the bigger brother of the "B&C beast", i.e. the 18sw115. The linearity of this driver was exemplary, especially for exursions below +-5mm. He also measured THD with an amount of input power resulting in an average midrange level of 104dB. THD stayed below 1% almost everywhere. And that is definitely very good. But there is one downside: This driver has a breakup mode around 1300 Hz (estimation) causing a 3rd order THD peak somewhere between 400Hz and 500Hz. The 15 inch version with the same motor will most probably show the same behaviour (only slightly higher up in frequency due to the higher breakup point). Which is a pity because the otherwise excellent performance would make it an interesting woofer for a loud high quality speaker (Geddes uses another slightly less Beefy B&C driver in his Summa BTW).
Regards
Charles
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I can see how a driver with high mechanical compliance would be desirable in modern speakers which tend to be small. Everyone wants a driver to go to zero in. 1/2ft^3 box. From what I have gleaned, Lower Q drivers can do quite well, but the box that it is used in becomes more of an important part of the equation. Its all about the trade offs. i spent some time today looking into other compression drivers. In particular, I looked at the 745neopb that Lynn and other are using. I did so because of his endorsemt but also because of the possibility of using Berylium diaphragms. Interestingly enough, I did not see an enormous gain in the top end when the Be diaphragms were used. Most still need help up top for true 20k extension. The closest thing i have seen to this standard is, in fact, the D2 that was suggested earlier. I am not sure anything better exist. Then again, can I hear a over 12-15k?
I told you -- super tweeter! We just need to find a proper one from 8-10k with 95db sensitivity. Let's listen to an upper midrange from this horn and see from that. If we like it, no reasons to spend money on a better horn. Better spend this money in a super tweet 🙂 i think...
Fortunatley I can't anymore ! 😉 Age definitley makes some things more expensive but also other things cheaper ! 😀
Does anyone remember the rule of 400,000 BTW ?
Saying that the product of lower and upper cutoff frequency should equal 400,000 in order to give a naturally balanced sound. Like 20 to 20,000 Hz or 40 to 10,000 Hz or whatever. Taking this one into account none of these speakers that don't go down to 20Hz need to go up to 20kHz by all means.
Regards
Charles
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