I love my BIB too, but too bad my very best friend took my drivers for his new project. I thought it would be better for me to look for a pair of new driver for the box - for the coming big screen tv system.
That baffle not only looks good, but sounds good too. I would make another pair with slimmer on both sides, and see if I'd have better highs.
Albert
Hello guys,
Greetings from Bulgaria!
For some time I was looking for easy and effective way to obtain good bass in my system, and now I think I have found it thanks to Mr. Martin King.
I will combine the H frames with full range drivers crafted by hand by local specialist, and probably with super tweeter, but that is another story. (I will post photos when I begin work on the project)
I have ordered a pair of Goldwood 1858 18 inch drivers, and the 13 mh Erse inductances, but I can't find the recommended by Martin Erse 400V 150uf capacitor. On the Erse's web page there are only 160uf 400V and 150uf 250V capacitors, no 400V 150uf...
My question is whether using for instance 3x50uf non polarized electrolytic capacitors which I can find locally or another combinations of capacitances resulting in summed capacitance of 150uf will do.
I think that because the element is in parallel the demands for high quality is not that big opposed to series circuit.
I have another question that is not that important, and it is what is your opinion on attenuating a speaker with a series resistor without the use of parallel impedance lowering resistance circuit regarding full range driver used only from the mid frequencies onwards. I ask that because I think that my 96db/w full range is a bit too sensitive and needs some attenuation...
And sub question related to this is whether the resistor should be before or after the crossover - either way it will affect the damping (I use solid state amplifier) but in the first case it will affect the values of the Ls and Cs less or not at all...
Second sub question is related to that I found out that none of the DiY-ers nor Mr. King Himself uses resistances for equalizing the sensitivity of the drivers. - why is that?
Wow! Allot of questions
Thank you in advance for the answers and best regards!
Greetings from Bulgaria!
For some time I was looking for easy and effective way to obtain good bass in my system, and now I think I have found it thanks to Mr. Martin King.
I will combine the H frames with full range drivers crafted by hand by local specialist, and probably with super tweeter, but that is another story. (I will post photos when I begin work on the project)
I have ordered a pair of Goldwood 1858 18 inch drivers, and the 13 mh Erse inductances, but I can't find the recommended by Martin Erse 400V 150uf capacitor. On the Erse's web page there are only 160uf 400V and 150uf 250V capacitors, no 400V 150uf...
My question is whether using for instance 3x50uf non polarized electrolytic capacitors which I can find locally or another combinations of capacitances resulting in summed capacitance of 150uf will do.
I think that because the element is in parallel the demands for high quality is not that big opposed to series circuit.
I have another question that is not that important, and it is what is your opinion on attenuating a speaker with a series resistor without the use of parallel impedance lowering resistance circuit regarding full range driver used only from the mid frequencies onwards. I ask that because I think that my 96db/w full range is a bit too sensitive and needs some attenuation...
And sub question related to this is whether the resistor should be before or after the crossover - either way it will affect the damping (I use solid state amplifier) but in the first case it will affect the values of the Ls and Cs less or not at all...
Second sub question is related to that I found out that none of the DiY-ers nor Mr. King Himself uses resistances for equalizing the sensitivity of the drivers. - why is that?
Wow! Allot of questions
Thank you in advance for the answers and best regards!
assuming you have a low dcr shunt inductor, I would put the attenuation resistor "before" the high pass network. I believe the inductor's dcr and nature of even order highpass network with shunt inductor across the driver is dominating the damping. I didn't build the whole project nor go for a final goal but briefly ran an 8" JBL on top of GW1858 H-frame and with series resistance attenuation before the highpass. Cone excursion on the fullrange was "ok" with 200 watt peaks into the system on odaiko drum cd tracks from a Carvin amp. GW1858 for its money was a pleasant surprise in MJK's H-frame.
You can use an electrolytic capacitor but I think you will have better result with the MKP film.
With a high performance electrolytic, low esr, the result could be also good.
Visaton sells a true bipolar smooth-foil capacitor, a high grade bipolar capacitor (82+68=150uF). I have used them (not in OB equalization) and the result seems good to my ears.
With a high performance electrolytic, low esr, the result could be also good.
Visaton sells a true bipolar smooth-foil capacitor, a high grade bipolar capacitor (82+68=150uF). I have used them (not in OB equalization) and the result seems good to my ears.
Thank you Ecir, Jerome and Pit! I will use the Visaton capacitors shielded with 2-3mm steel sheet... due to voltage concerns... eventually after I listen to the system for a while I will award it with 40 dollar capacitors.
Guglielmope I am also from Europe and found that there is something wrong with the delivery options in the parts express store. For 340 dollars worth of speakers it returns 540 dollars delivery fee.
Fortunately I have a friend in the USA who will receive the speakers first at only a 5-7$ additional delivery fee for fast delivery and then she will post the parts to me with ordinary mail for about 105-110$. The post fee is about 105-110$ and the UPS lowest rate is about 110-114$ to Bulgaria.
To Italy the fee should be even lower.
This is it from me for now I will upload some photos when the speakers are ready.
EDIT: the 110$ transport fee is for two GW1858 and two Erse inductances, total price is 220$ (the inductances are dicounted at parts expreess), so 110$ delivery fee sounds acceptable.
Guglielmope I am also from Europe and found that there is something wrong with the delivery options in the parts express store. For 340 dollars worth of speakers it returns 540 dollars delivery fee.
Fortunately I have a friend in the USA who will receive the speakers first at only a 5-7$ additional delivery fee for fast delivery and then she will post the parts to me with ordinary mail for about 105-110$. The post fee is about 105-110$ and the UPS lowest rate is about 110-114$ to Bulgaria.
To Italy the fee should be even lower.
This is it from me for now
I will upload some photos when the speakers are ready.EDIT: the 110$ transport fee is for two GW1858 and two Erse inductances, total price is 220$ (the inductances are dicounted at parts expreess), so 110$ delivery fee sounds acceptable.
Hi,
Very hard to find an equivalent in Europe. I saw these speakers but they shouldn't fit because Qts is a far too low.
SM118/N Beyma 18" Qts~0.5 400€ for 2
A&D Audio R1830 Qts ~ 0.6 230€ for 2.
Hello,
seems impossible that in Europe we can't find a woofer like that.
I've found:
18 INCH BASS BOX PA-LOUDSPEAKER 450 MM 45 CM 450MM 45CM su eBay.it Sonstige, DJ-Equipment, Audio Hi-Fi
only 59,90 eur but the Qts =0,62 is not suitable for this design.
May be we can try to start a new thread looking fo a new woofer lake Goldwood.
What do you think about?
Ciao
Guglielmo
seems impossible that in Europe we can't find a woofer like that.
I've found:
18 INCH BASS BOX PA-LOUDSPEAKER 450 MM 45 CM 450MM 45CM su eBay.it Sonstige, DJ-Equipment, Audio Hi-Fi
only 59,90 eur but the Qts =0,62 is not suitable for this design.
May be we can try to start a new thread looking fo a new woofer lake Goldwood.
What do you think about?
Ciao
Guglielmo
Hi,
It seems to be a very nice performer better than I found. In general, not always, the Qts will be a little higher.
I think you can use it but the low end roll off will be earlier and the sensitivity could be lower. I have used in my OB a Perless 830669 Qts ~0.47, I have measured 0.6 on air, 0.7 on the panel and it has worked well to my ears.
Take a look to MJK comparison between Alpha 15, Beta 15 and Gamma 15 The difference between an Alpha 15 (QTs~1.3) and a Beta 15 (Qts~0.6) is perfectly manageable because the responses are not very far
It will be nice if someone makes simulations in order to compare. I think like you an European project could be made ? Goldwood is not distributed in Europe
Cheers.
It seems to be a very nice performer better than I found. In general, not always, the Qts will be a little higher.
I think you can use it but the low end roll off will be earlier and the sensitivity could be lower. I have used in my OB a Perless 830669 Qts ~0.47, I have measured 0.6 on air, 0.7 on the panel and it has worked well to my ears.
Take a look to MJK comparison between Alpha 15, Beta 15 and Gamma 15 The difference between an Alpha 15 (QTs~1.3) and a Beta 15 (Qts~0.6) is perfectly manageable because the responses are not very far
It will be nice if someone makes simulations in order to compare. I think like you an European project could be made ? Goldwood is not distributed in Europe
Cheers.
Well, we have one secret wunderwaffe in Europe: Monacor.
MONACOR INTERNATIONAL:Gesamtprogramm
Whatever the TSP you need, whatever the € you have, you want to have a look.
Mind - they don´t spend much money on cosmetics; some very good drivers lookugly - better not allow the missus to see them before you´ve wielded some creativity.
MONACOR INTERNATIONAL:Gesamtprogramm
Whatever the TSP you need, whatever the € you have, you want to have a look.
Mind - they don´t spend much money on cosmetics; some very good drivers look
ugly - better not allow the missus to see them before you´ve wielded some creativity.
From general knowledge and from what I have read from Mr. King I think, that lower QTS might be overcome with the amount of air-load on the membrane.
One cubic meter (1000 liters/35,245 cu. ft.) of air weights approximateli 1100-1200 grams, thus 1.2 grams per liter. This means that the ~100 liters of volume of the '18 H-frame loads the membrane with additional 120 grams - 60 on each side. To be maximally circumstantial in that aspect I should point that the speaker should be forward from center not only because of the geometry center of the membrane, but additionally because of the slightly smaller rear area lacking the area of the dust cap...- this in order to obtain maximum equity of the load.
So with lower QTS drivers measures should be taken in order to achieve greater membrane load and I think here we depend more on the laws of fluid dynamics than on the acoustics.
My Idea is simple - to be used a known good flowing cross section either with straight and constant angle or some sort of horn-like curve. But in the case with bass reproduction and external dimensions concerns this horn like design will most probably used under it's frequency range and it would serve only as speaker to air coupler.
Having in mind the resistance which every fluid renders to compression and especially the resistance of moving air to decreasing cross-sections the angle near speaker should be in the range 2.5-3.5 degrees per side.
For instance 51cm/20 in. length of the horn-like "acoustic" loader is equal to quarter wave of 163hz and half wave of 326hz... this acoustic "outfit" would hold up to 200 liters of air freely moving back and forth - coupled well to the membrane - this is 250 grams of load.
If you operate this speaker under 163hz the only function of the "horn" would be the loading of the membrane with additional 250 grams.
If the system is symmetrical there would be 500 grams additional load, which is half a kilo... but I doubt a 1 meter deep dipole will act as a dipole and disappear...
The good part is that if the design is really good flowing in both directions it does not need to be replicated at the back of the speaker - one "horn" will load both forward and backward movements equally.
What do you think on my Idea?
One cubic meter (1000 liters/35,245 cu. ft.) of air weights approximateli 1100-1200 grams, thus 1.2 grams per liter. This means that the ~100 liters of volume of the '18 H-frame loads the membrane with additional 120 grams - 60 on each side. To be maximally circumstantial in that aspect I should point that the speaker should be forward from center not only because of the geometry center of the membrane, but additionally because of the slightly smaller rear area lacking the area of the dust cap...- this in order to obtain maximum equity of the load.
So with lower QTS drivers measures should be taken in order to achieve greater membrane load and I think here we depend more on the laws of fluid dynamics than on the acoustics.
My Idea is simple - to be used a known good flowing cross section either with straight and constant angle or some sort of horn-like curve. But in the case with bass reproduction and external dimensions concerns this horn like design will most probably used under it's frequency range and it would serve only as speaker to air coupler.
Having in mind the resistance which every fluid renders to compression and especially the resistance of moving air to decreasing cross-sections the angle near speaker should be in the range 2.5-3.5 degrees per side.
For instance 51cm/20 in. length of the horn-like "acoustic" loader is equal to quarter wave of 163hz and half wave of 326hz... this acoustic "outfit" would hold up to 200 liters of air freely moving back and forth - coupled well to the membrane - this is 250 grams of load.
If you operate this speaker under 163hz the only function of the "horn" would be the loading of the membrane with additional 250 grams.
If the system is symmetrical there would be 500 grams additional load, which is half a kilo... but I doubt a 1 meter deep dipole will act as a dipole and disappear...
The good part is that if the design is really good flowing in both directions it does not need to be replicated at the back of the speaker - one "horn" will load both forward and backward movements equally.
What do you think on my Idea?
I have searched allot. In Bulgaria there are about 3 significant driver manufacturers, they are as follows:
1. Oberton Oberton Professional Sound Systems
Highest QTS driver from them is about 0.36, there are several under 0.2 and most 0.2xx
Prices are in the 50-250 Euro range
2. Blagoevgrad AD (this is a name of a city) known outside Bulgaria as "VKN" Vissokogovoriteli PLC, Blagoevgrad, Bulgaria
Mediocre speakers with some great examples and some really embarassing "creations"
This is their largest speaker:
VKN 13310/311
Sale price about 75 Euro
These are really good sounding:
VKN 12211/311
Small magnet probably high QTS sale price in Bulgaria about 30-40 Euro
I think for a good OB system might be needed up to 4 of them per side, but two will work well as well...
3. Ribbon high frequency drivers NDRL AUDIO RESEARCH LABORATORY :: Home
I have four of them and will probably will order another two or four for my OB.
For more than a year I have searched for speakers capable of good bass reproduction without the enclosure to be big and complicated... I have found only the MJK solution and no one that I know knows of any similar solution...
The only close proximity is 200-300L (10 cu. ft.) bass reflex box with only 12 inch driver... because most 15-18 inch drivers are for pro purposes and have great sensitivity and high resonance.
I have found that http://bmsspeakers.com/cone-speaker-compression-driver/bms-neodymium-cone-speakers/bms-neodymium-cone-extended-low/ while searching for the other sites.
And especially this one http://bmsspeakers.com/fileadmin/bms-data/product_data/cone_drivers/neodymium/15_18/bms_15n840v2_t_data.pdf
The frequency response is such that if you cut it around 100 hz it will return some very good bass extension...
This http://bmsspeakers.com/fileadmin/bms-data/product_data/cone_drivers/neodymium/15_18/bms_18n850v2_t_data.pdf looks frightening as well... low resonance good looking response considering that it is measured in a sealed box...
All of those I think will be favored if front loaded with "a good flowing horn like enclosure".
Above I mention the flow characteristics of the contour, because the goal is to secure equal air passage back and forth. While the pumping out is always easy through expanding cross section, the suction will be difficult if angles are too steep and pressure disintegration might occur. And the sense of that is to make the air in the enclosure (the contour) act as hard attached column, thus improving efficiency and loading the membrane with the weight of the "column".
Best regards.
1. Oberton Oberton Professional Sound Systems
Highest QTS driver from them is about 0.36, there are several under 0.2 and most 0.2xx
Prices are in the 50-250 Euro range
2. Blagoevgrad AD (this is a name of a city) known outside Bulgaria as "VKN" Vissokogovoriteli PLC, Blagoevgrad, Bulgaria
Mediocre speakers with some great examples and some really embarassing "creations"
This is their largest speaker:
VKN 13310/311
Sale price about 75 Euro
These are really good sounding:
VKN 12211/311
Small magnet probably high QTS sale price in Bulgaria about 30-40 Euro
I think for a good OB system might be needed up to 4 of them per side, but two will work well as well...
3. Ribbon high frequency drivers NDRL AUDIO RESEARCH LABORATORY :: Home
I have four of them and will probably will order another two or four for my OB.
For more than a year I have searched for speakers capable of good bass reproduction without the enclosure to be big and complicated... I have found only the MJK solution and no one that I know knows of any similar solution...
The only close proximity is 200-300L (10 cu. ft.) bass reflex box with only 12 inch driver... because most 15-18 inch drivers are for pro purposes and have great sensitivity and high resonance.
I have found that http://bmsspeakers.com/cone-speaker-compression-driver/bms-neodymium-cone-speakers/bms-neodymium-cone-extended-low/ while searching for the other sites.
And especially this one http://bmsspeakers.com/fileadmin/bms-data/product_data/cone_drivers/neodymium/15_18/bms_15n840v2_t_data.pdf
The frequency response is such that if you cut it around 100 hz it will return some very good bass extension...
This http://bmsspeakers.com/fileadmin/bms-data/product_data/cone_drivers/neodymium/15_18/bms_18n850v2_t_data.pdf looks frightening as well... low resonance good looking response considering that it is measured in a sealed box...
All of those I think will be favored if front loaded with "a good flowing horn like enclosure".
Above I mention the flow characteristics of the contour, because the goal is to secure equal air passage back and forth. While the pumping out is always easy through expanding cross section, the suction will be difficult if angles are too steep and pressure disintegration might occur. And the sense of that is to make the air in the enclosure (the contour) act as hard attached column, thus improving efficiency and loading the membrane with the weight of the "column".
Best regards.
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