Workin' on the chain gang!
I suggest you use different chains for the hanging woofer- there are chains sold within vinyl covers that would be less likely to ring or rattle in use, plus would allow you a built-in damping layer at the suspension points.
I suggest you use different chains for the hanging woofer- there are chains sold within vinyl covers that would be less likely to ring or rattle in use, plus would allow you a built-in damping layer at the suspension points.
Or, steel wires also do a very good job. I'm using steel wire of about 3mm O.D. to suspend my horns. I think 2 or 4 wires in this size are good for 20kg or more. Organizing the drivers in groups and separate the loads, these skinny-looking stuff should be fine. 😀
I dont have problems with ringing or rattling with the chains, but I do get your point... Chains are very easy when prototyping at least. Steel wire would probably look a lot nicer for a final "production" speaker. I'm still at the prototype stage here, so...
I just got a new truckload of drivers from Beyma, including a lot of 12". Will try to replace the 15" with two 12" to see if that works well. There is room for two 12" below the mids and tweeter. That will give me some more cone area in the low mid/upper bass (50-300 Hz). It will also look a lot slimmer.
Here a sketch of it, with one 21" subwoofer in H-baffle:
I just got a new truckload of drivers from Beyma, including a lot of 12". Will try to replace the 15" with two 12" to see if that works well. There is room for two 12" below the mids and tweeter. That will give me some more cone area in the low mid/upper bass (50-300 Hz). It will also look a lot slimmer.
Here a sketch of it, with one 21" subwoofer in H-baffle:
An externally hosted image should be here but it was not working when we last tested it.
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I like the proportions of the 2-12s. Is the current plan to use the H baffle 21 as a sub with the 2-12s?
It must be nice to have numbers of drivers flowing past as you do!
It must be nice to have numbers of drivers flowing past as you do!
Exciting stuff...!
Hi Stig Erik,
Just wanted to say congratulations, you are really developing something special here. I really admire your relentless work ethic " Build it and they will come" combined with enough test and measure to move you on to the next stage.
This really is what high end audio needs and this thread shows the kind of collaboration and DIY spirit that NASA and SETI employ with their global network of DIY researchers looking for prime numbers and signal continuity, beautiful ...!!!
Just a suggestion on the Beyma drivers as you are the Beyma Dude round here...!
The 15 inch Neo 15LW30 is a real gem, (up there with the Volt 2500.4 and Beyma 12LX60). The 15LW30 combines 90% of the Volt speed with really powerful low end, even better than the 12LX60, and its beautifully smooth all the way out to 2Khz. In fact plus or minus 1.5dBfrom 100Hz to 2 KHz!
I totally understand that two 12 inch will be slimmer and a bit more cone area, personally I use a VPL wing and baffle with a single 15 inch ( Precision Devices PD158) to avoid having to use any EQ boost in the 80Hz to 400Hz band that it covers.
Anyway your doing an amazing job and I look forward to the finished design, I would love to pop over in the Spring if you have some spare time.
Cheers
Derek.
Hi Stig Erik,
Just wanted to say congratulations, you are really developing something special here. I really admire your relentless work ethic " Build it and they will come" combined with enough test and measure to move you on to the next stage.
This really is what high end audio needs and this thread shows the kind of collaboration and DIY spirit that NASA and SETI employ with their global network of DIY researchers looking for prime numbers and signal continuity, beautiful ...!!!
Just a suggestion on the Beyma drivers as you are the Beyma Dude round here...!
The 15 inch Neo 15LW30 is a real gem, (up there with the Volt 2500.4 and Beyma 12LX60). The 15LW30 combines 90% of the Volt speed with really powerful low end, even better than the 12LX60, and its beautifully smooth all the way out to 2Khz. In fact plus or minus 1.5dBfrom 100Hz to 2 KHz!
I totally understand that two 12 inch will be slimmer and a bit more cone area, personally I use a VPL wing and baffle with a single 15 inch ( Precision Devices PD158) to avoid having to use any EQ boost in the 80Hz to 400Hz band that it covers.
Anyway your doing an amazing job and I look forward to the finished design, I would love to pop over in the Spring if you have some spare time.
Cheers
Derek.
Yes and yes 🙂
The H-baffle sub will cover 25 Hz to around 60 Hz, depending of how low the twin 12" will go without complaints.
Derek,
I will check out the 15LW30!
You are of course most welcome for a visit. I live just one hour away from Oslo airport, so its easy to get here.
I will check out the 15LW30!
You are of course most welcome for a visit. I live just one hour away from Oslo airport, so its easy to get here.
I use them in dipole mode down to 1440hz (in a baffle) and it sounds great! No measurements though, just my ears... 😀
Btw, the Neo3 has more bottom end without the cup than with it. I remember seeing measurements from Zaph years ago.
Maybe you can use cheap speakercables similar to these for speakermounting/hanging. 🙂
An externally hosted image should be here but it was not working when we last tested it.
Yes, I was actually thinking of using the speaker wires to hang the drivers. Will be a lot of wires though. The nice thing about using chains is that I need just two chains, all speakers are attached to those two.
Hi Stig Erik,
That’s a shame Beyma are discontinuing the 15 LW30, I really liked its sound and its great value.
The new 12P80 Nd looks sweet on paper, I have not tried it but it’s a dream spec for your true "free air design". I only have a preliminary data sheet but 64g Mms with a Bl of 23.7 is fantastic. Plus the distortion graphs look almost too good to be true below 150Hz.
I would think a pair of these covering the 60Hz UP to 400Hz or 500Hz will really work beautifully. They are effectively 95dB to 96dB / 1 watt sensitivity from 140 Hz all the way to 1 KHz so a pair will be a close match for the TPL AMT.
Plenty of travel and good XMax if you give them a lot of EQ. The 45 Hz Fs and 0.16 (!) Qts actually will work in your favour as you are not trying to get bass out of them. Low mass / high Bl, low Qts, well ventilated 4 inch voice coil, linen surround, and tight suspension all add up to open baffle / free air super accurate midrange, on paper....!
I would love to hear what you think if you can test them out in your new design.
PS the 15 P80/Nd looks very interesting too....!
All the best
Derek.
That’s a shame Beyma are discontinuing the 15 LW30, I really liked its sound and its great value.
The new 12P80 Nd looks sweet on paper, I have not tried it but it’s a dream spec for your true "free air design". I only have a preliminary data sheet but 64g Mms with a Bl of 23.7 is fantastic. Plus the distortion graphs look almost too good to be true below 150Hz.
I would think a pair of these covering the 60Hz UP to 400Hz or 500Hz will really work beautifully. They are effectively 95dB to 96dB / 1 watt sensitivity from 140 Hz all the way to 1 KHz so a pair will be a close match for the TPL AMT.
Plenty of travel and good XMax if you give them a lot of EQ. The 45 Hz Fs and 0.16 (!) Qts actually will work in your favour as you are not trying to get bass out of them. Low mass / high Bl, low Qts, well ventilated 4 inch voice coil, linen surround, and tight suspension all add up to open baffle / free air super accurate midrange, on paper....!
I would love to hear what you think if you can test them out in your new design.
PS the 15 P80/Nd looks very interesting too....!
All the best
Derek.
Hanging versus mounting via the rear of the magnet
Very cool that you can get great sound out of hanging drivers. It really shows that you can never know how good something will sound until you actually listen to it. Don't the mids still shake (modulate) the tweeter visibly? Measurably? It's not as easy but would a tree of mounts fastened to the magnets be more stable and still allow you to eliminate the baffle?
Very cool that you can get great sound out of hanging drivers. It really shows that you can never know how good something will sound until you actually listen to it. Don't the mids still shake (modulate) the tweeter visibly? Measurably? It's not as easy but would a tree of mounts fastened to the magnets be more stable and still allow you to eliminate the baffle?
Hi Derek,
You always have good insight about Beyma speakers!
How much better do you think it would be vs my current SM112N (which i find VERY good and a steal for the price).
Going to use 2x each speaker in my next project, in the 70-250hz range.
Ok folks, now I have two Beyma 12P1000nd in each dipole instead of the 15". Bass quantity is virtually the same as a single 15". When it comes to sound quality, I really like the dual 12". 🙂
Beyma drivers
Hi Telstar,
Glad you are happy with the Beyma SM112 drivers.
As I have not heard the new Beyma 12P80 Nd I am only going by the paper spec.
On paper the new Neo driver really is at the top of the wish list for 12 inch open baffle / free air upper bass / low mid.
Probobly Stig Erik is the best qualified to judge subjective sound quality...
Over to you Stig Erik!
Cheers
Derek.
Hi Telstar,
Glad you are happy with the Beyma SM112 drivers.
As I have not heard the new Beyma 12P80 Nd I am only going by the paper spec.
On paper the new Neo driver really is at the top of the wish list for 12 inch open baffle / free air upper bass / low mid.
Probobly Stig Erik is the best qualified to judge subjective sound quality...
Over to you Stig Erik!
Cheers
Derek.
I just finished to compare the specs.
In the critical range for me, distortion of the SM112N isn't much worse at all (it is at lower frequencies, and i noticed that if i overdo with the equalization). It can only sound better when i will highpass them 🙂
The 12P80 is much better on Xmax and especially the bigger voice coil. The neodymium magnet should have also some advantages (4db more efficiency is good but not do die for)
Will do some derived parameter and put all specs in my worksheets.
Hope the price isnt too high, though. Will never stress enough the SM112N is a price/perf champion.
For Erik, I checked the graph of the 12P100 as well, and well the distortion figures are much WORSE than the little brother. I know u can try the P80 too 😉 Do it.
Yes, 2x 12" are more or less the same MOL than a single 15" but with less distortion. That's definitely the way i'm going.