Hi
I have one Beyma 18 G550 woofer will it work for the HE?
Before I run out and invest in another one I would like to know if it will work out, another thing is that the Beyma I allready have is about 15 years old. I might have used it for about 50 hours at quit low levels. Will it match with a new One?
best regards
uwe
I have one Beyma 18 G550 woofer will it work for the HE?
Before I run out and invest in another one I would like to know if it will work out, another thing is that the Beyma I allready have is about 15 years old. I might have used it for about 50 hours at quit low levels. Will it match with a new One?
best regards
uwe
Glad you built them and like them. Please keep us informed of how they change with some driver break in.Here comes an update after 150+ hours with my Ultras. I'm VERY pleased with the performance of the Ultras. I've becomed addicted to the smooth and open sound and the very powerful, low octave bass. I heartily recommend building or buying these excellent speakers from John (Welcome To Manzanita Audio Solutions . Open Baffle Dynamic Speaker Designs).
\Hans in Holmsund, Sweden.
\Hans in Holmsund, Sweden.
Nice to know you are enjoying the fruits of your efforts
Hanns....
Thanks for sharing your opinion of the Ultra build! Know it was a lot of work to obtain the GRS in Sweden.
I fear a lot of potential builders have difficulty believing how good such a simple design and build can be. And they worry about the intrinsic low efficiency. However, if you run the numbers and measure most designs that can really play flat into the upper 20's, you will usually find one of two outcomes.
1) The enclosure is the size of a double door refrigerator, or... 2) The true efficiency is similar if not less than the Ultra. As best I can measure, the Ultra is around 84-85 dbw. And that is all the way down. No roll-off!
Provide a clean 20-40 watts per channel in a typical domestic setting.... for most music, you have more than enough output.
Funny thing about the Ultra is the tonal purity of the bass. It's all most creepy to hear true fundamentals with out the usual doubling nearly ALL speakers regardless of design produce below 50 Hz or so. That is why the Ultra low end is SO addictive... as you observered.
Hanns....
Thanks for sharing your opinion of the Ultra build! Know it was a lot of work to obtain the GRS in Sweden.
I fear a lot of potential builders have difficulty believing how good such a simple design and build can be. And they worry about the intrinsic low efficiency. However, if you run the numbers and measure most designs that can really play flat into the upper 20's, you will usually find one of two outcomes.
1) The enclosure is the size of a double door refrigerator, or... 2) The true efficiency is similar if not less than the Ultra. As best I can measure, the Ultra is around 84-85 dbw. And that is all the way down. No roll-off!
Provide a clean 20-40 watts per channel in a typical domestic setting.... for most music, you have more than enough output.
Funny thing about the Ultra is the tonal purity of the bass. It's all most creepy to hear true fundamentals with out the usual doubling nearly ALL speakers regardless of design produce below 50 Hz or so. That is why the Ultra low end is SO addictive... as you observered.
Albertli: BOM for the Ultra is on The best affordable DIY open baffle loudspeaker I've listened to so far. and the design/crossover is on the next page. The components at PE now cost $208... with the wood being extra.
Pano, John: The 20mH inductors are backordered at PE. Any replacements?
Pano, John: The 20mH inductors are backordered at PE. Any replacements?
Ultra essentials!!
Hello all...
I am providing the current build info in two parts...
First is a Bill of Materials....
Second will be a separately posted schematic diagram...
BOM & schematic can be matched up to complete the build....
OK.... BOM.....
L1 Woofer 1st order low pass electrical inductor. 18-22 MH Iron core. 15-16 ga. Default part at the moment is PE P/N 266-960 (16 ga. 20 MH)
L2 H.F. trap inductor 2.75 MH air core Perfect Lay Solen. 14 Ga. (Madisound) Range can vary from 2.4 - 2.90 MH Also available from PE.
C1 H.F. 1st order electrical high pass capacitor. 6.0 MFD. Possible PE P/N 027-236. 5.5 - 6.5 MFD to suit. Higher cost caps of equal MFD value are available from numerous sources. Look for 200 Volt or higher Poly, film and foil, MKP or Oil construction.
R1 HF trap bypass resistor... 15.0 ohm, 5-10 watt low noise MILS. Range can vary from 12-25 ohms.
R2 H.F Pad...8.0 ohm, 5-10 watt low noise MILS. Range can vary from 7-9 ohms.
Woofer. GRS-15PF-8 15" woofer. PE P/N 292-415.
Mid-tweeter. Vifa TC9FD18-08. PE 264-1062. Also available at Madisound.
Hello all...I am providing the current build info in two parts...
First is a Bill of Materials....
Second will be a separately posted schematic diagram...
BOM & schematic can be matched up to complete the build....
OK.... BOM.....
L1 Woofer 1st order low pass electrical inductor. 18-22 MH Iron core. 15-16 ga. Default part at the moment is PE P/N 266-960 (16 ga. 20 MH)
L2 H.F. trap inductor 2.75 MH air core Perfect Lay Solen. 14 Ga. (Madisound) Range can vary from 2.4 - 2.90 MH Also available from PE.
C1 H.F. 1st order electrical high pass capacitor. 6.0 MFD. Possible PE P/N 027-236. 5.5 - 6.5 MFD to suit. Higher cost caps of equal MFD value are available from numerous sources. Look for 200 Volt or higher Poly, film and foil, MKP or Oil construction.
R1 HF trap bypass resistor... 15.0 ohm, 5-10 watt low noise MILS. Range can vary from 12-25 ohms.
R2 H.F Pad...8.0 ohm, 5-10 watt low noise MILS. Range can vary from 7-9 ohms.
Woofer. GRS-15PF-8 15" woofer. PE P/N 292-415.
Mid-tweeter. Vifa TC9FD18-08. PE 264-1062. Also available at Madisound.
300 B potential
The Ultra is approximately 84 dbw at one meter with the baffle face 36"- 48" from a sheet rocked rear wall. So, I recommend at least 10 watts RMS per channel at 8 ohms. I have driven it with a 5 WPC SE KT88 and for low to moderate listening that is fine. (90 db peaks from the pair at a typical listening position) But to get it to really sing, 20 - 50 WPC is what's needed. This speaker really loves tube amplification. Quality P/PT or SET.
John
The Ultra is approximately 84 dbw at one meter with the baffle face 36"- 48" from a sheet rocked rear wall. So, I recommend at least 10 watts RMS per channel at 8 ohms. I have driven it with a 5 WPC SE KT88 and for low to moderate listening that is fine. (90 db peaks from the pair at a typical listening position) But to get it to really sing, 20 - 50 WPC is what's needed. This speaker really loves tube amplification. Quality P/PT or SET.
John
Power Requirements for extended response passive OB's
This is a common and important topic... there is no single - simple answer that will settle this issue. Too many variables... the usual stuff... room size... Room dimensions, listening tastes, music types, low end bass extension preferences, it goes on for ever.
From a personal stand point... generally speaking, making a host of assumptions to be sure... a majority of listeners, a majority of the time, rarely exceed an average SPL of 85 db at the listening position. Given that, if you have a system that can provide clean peaks 10 db higher, you are in good shape.
So... a speaker that has a true operating efficiency in the mid 80's per watt, that does not roll off before reaching 30 Hz, you are working with a winner! 30watts of clean triode power will get you where you need to be.
If you want movie theater 100 db plus capabilities, that is a whole different situation. Especially if you need the bass extension to extend to subterranean extremes at lease breaking levels.
This is a common and important topic... there is no single - simple answer that will settle this issue. Too many variables... the usual stuff... room size... Room dimensions, listening tastes, music types, low end bass extension preferences, it goes on for ever.
From a personal stand point... generally speaking, making a host of assumptions to be sure... a majority of listeners, a majority of the time, rarely exceed an average SPL of 85 db at the listening position. Given that, if you have a system that can provide clean peaks 10 db higher, you are in good shape.
So... a speaker that has a true operating efficiency in the mid 80's per watt, that does not roll off before reaching 30 Hz, you are working with a winner! 30watts of clean triode power will get you where you need to be.
If you want movie theater 100 db plus capabilities, that is a whole different situation. Especially if you need the bass extension to extend to subterranean extremes at lease breaking levels.
5W and 84dB/W @ 1m will not satisfy many listeners.
25W and 84dB/W @ 1m will sound adequate for quite a few listeners on certain types of music source.
100W and 84dB/W @ 1m will sound good for many listeners for most types of music source.
I arrive at these conclusions by basing my experience on average listening levels and comparing those average listening levels to the very necessary overhead required for the peaks that far exceed the average levels.
case 1. 5W + 84dB = 91dB @ 1m
case 2. 25W +84dB = 98dB @ 1m
case 3. 100W + 84dB = 104dB @ 1m
From these peak levels subtract 10dB to 30dB for the peak to average overhead.
Subtract 8dB for listening at 2.4m
Add 3db for using two speakers at typical stereo separation distances
Apply -10dB & -8dB & +3 dB to case 1 and you end up with average listening levels that cannot exceed ~76dB
25W and 84dB/W @ 1m will sound adequate for quite a few listeners on certain types of music source.
100W and 84dB/W @ 1m will sound good for many listeners for most types of music source.
I arrive at these conclusions by basing my experience on average listening levels and comparing those average listening levels to the very necessary overhead required for the peaks that far exceed the average levels.
case 1. 5W + 84dB = 91dB @ 1m
case 2. 25W +84dB = 98dB @ 1m
case 3. 100W + 84dB = 104dB @ 1m
From these peak levels subtract 10dB to 30dB for the peak to average overhead.
Subtract 8dB for listening at 2.4m
Add 3db for using two speakers at typical stereo separation distances
Apply -10dB & -8dB & +3 dB to case 1 and you end up with average listening levels that cannot exceed ~76dB