The HP10Ws are definite keepers. They simply outclass anything up to twice it's price or more in performance, both in sensitivity and sound quality. I'll be making some minor changes though, like adding a phase plug with a rod that will connect the 2 speakers mechanically through the center.
The amp6basic is going to be replaced with an amp9basic, and it's going to run on LFP cells instead of SLAs. A new 15W amorphous solar panel will cover the entire top. It's also going to have a switch to toggle between 12V and 24V mode.
The methanol fuel cell idea is dropped as it's not practical and it's highly dangerous to combine methanol with ethanol (the former being the fuel, and the latter being what the user is intoxicated by).
Some minor changes to the design is also considered and I'm testing different tweeter solutions but a high quality piezo driven horn with a Geddes-style waveguide is showing the most promise right now.
The amp6basic is going to be replaced with an amp9basic, and it's going to run on LFP cells instead of SLAs. A new 15W amorphous solar panel will cover the entire top. It's also going to have a switch to toggle between 12V and 24V mode.
The methanol fuel cell idea is dropped as it's not practical and it's highly dangerous to combine methanol with ethanol (the former being the fuel, and the latter being what the user is intoxicated by).
Some minor changes to the design is also considered and I'm testing different tweeter solutions but a high quality piezo driven horn with a Geddes-style waveguide is showing the most promise right now.
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Saturnus, while you wait to start your next project, maybe you can shoot me some pointers with my new project. First off, thanks for sharing your project with us and even more thanks for all the advice you've given on this forum.
What are your thoughts on the piezos listed below.
I'm building a 2 woofer version much like the green machine whelibob posed a couple pages back.
2x woofers = Goldwood GW-1058
amp = sure electronics 2*100 t-amp
power = probably 2x 7ah SLAs wired for 24V
solar = TBD
piezos = Need help deciding between the KSN1005A (http://www.adelcom.net/MOTOROLA_ksn1005b.htm) and the motorola/CTS powerline version KSN1141A (http://www.adelcom.net/MOTOROLA_ksn1141a.htm)
This post is the reason I'm even thinking of the powerline version. http://www.audiokarma.org/forums/showthread.php?t=79659
You are right that the GW-1058 charts very similarly to the p.audio woofer. The GW1058 appears to have just a little more low end reach at the expense of a little sensitivity. I'm still playing around with the enclosure volume/tuning and find myself leaning towards a larger volume to gain a lower F3. With a 25L enclosure, I'm seeing an F3 in the lower 60s hz range. Although I loose a little of the peak at around 100-110hz when doing this. Or a 20L enclosure brings the F3 up to somewhere in the 70s.
Early on in this thread you mentioned that trying to tune for lower than 100 hz isn't worthwhile for outdoor environments. If the additional size isn't a major issue, can you think of any reason why one wouldn't try to achieve a lower F3? With the bigger t-amp, I have a bit more headroom to play with as well which could come in handy in this frequency range. Thoughts?
Thanks
What are your thoughts on the piezos listed below.
I'm building a 2 woofer version much like the green machine whelibob posed a couple pages back.
2x woofers = Goldwood GW-1058
amp = sure electronics 2*100 t-amp
power = probably 2x 7ah SLAs wired for 24V
solar = TBD
piezos = Need help deciding between the KSN1005A (http://www.adelcom.net/MOTOROLA_ksn1005b.htm) and the motorola/CTS powerline version KSN1141A (http://www.adelcom.net/MOTOROLA_ksn1141a.htm)
This post is the reason I'm even thinking of the powerline version. http://www.audiokarma.org/forums/showthread.php?t=79659
You are right that the GW-1058 charts very similarly to the p.audio woofer. The GW1058 appears to have just a little more low end reach at the expense of a little sensitivity. I'm still playing around with the enclosure volume/tuning and find myself leaning towards a larger volume to gain a lower F3. With a 25L enclosure, I'm seeing an F3 in the lower 60s hz range. Although I loose a little of the peak at around 100-110hz when doing this. Or a 20L enclosure brings the F3 up to somewhere in the 70s.
Early on in this thread you mentioned that trying to tune for lower than 100 hz isn't worthwhile for outdoor environments. If the additional size isn't a major issue, can you think of any reason why one wouldn't try to achieve a lower F3? With the bigger t-amp, I have a bit more headroom to play with as well which could come in handy in this frequency range. Thoughts?
Thanks
amp 6 and others can drive 4 ohm also. I presume the choice of amp9 is because of the higher output (he mentions 24v operation).
The basic version is cheaper as it has no rectifier and bulk caps, but other than that they are similar. It does not matter with the rectifier when he uses 12/24v DC.
The basic version is cheaper as it has no rectifier and bulk caps, but other than that they are similar. It does not matter with the rectifier when he uses 12/24v DC.
Your assumptions are very accurate, Havoc08. Indeed the amp6b plays 4 Ohm, and even 2 Ohms for that matter but the amp9b has 24V potential to get 4 times as much output power. Now the 24V mode will only be available when supplied with external (usually grid) power.
Indeed I have found the HP10W in 4 Ohms, it's called the HP10W4. But I also need 4 channels as I'm going to use an active x-over to drive the tweeters and the woofers separately.
I don't need the rectifier and power supply in the amp9s, nor I'm a masochist that enjoys winding 4 sets of coils myself when the ready-made ones in the amp9b (and amp6b) are much better.
Saulty, to answer you question most thoughroughly. I'd like you to make 3 mp3, one each with a 60, a 80 and a 100 Hz sinus wave. Now take a speaker you know is capable of playing those at fairly loud levels outside and put in the middle of a grassfield. Stand back 4-5 meters and play the mp3s. Then you'll know why it's completely redundant going lower than roughly 100Hz for semi-loud applications outdoors.
The Motorolas have a good reputation but they aren't the best piezos you can get regardless of claims to the contrary. The Zomax HP100s I use in the Boominator simply are the best piezo horns I have ever heard. It beats every Motorola horn by a mile. You can get even better ones though but those are dedicated horn drivers that need a (normally threaded) horn, and at a very different price point.
Btw, you do know that with your amp and 2 7Ah SLA in series for 24V you'll only get around 2½-3 hours playing time max, right?
Indeed I have found the HP10W in 4 Ohms, it's called the HP10W4. But I also need 4 channels as I'm going to use an active x-over to drive the tweeters and the woofers separately.
I don't need the rectifier and power supply in the amp9s, nor I'm a masochist that enjoys winding 4 sets of coils myself when the ready-made ones in the amp9b (and amp6b) are much better.
Saulty, to answer you question most thoughroughly. I'd like you to make 3 mp3, one each with a 60, a 80 and a 100 Hz sinus wave. Now take a speaker you know is capable of playing those at fairly loud levels outside and put in the middle of a grassfield. Stand back 4-5 meters and play the mp3s. Then you'll know why it's completely redundant going lower than roughly 100Hz for semi-loud applications outdoors.
The Motorolas have a good reputation but they aren't the best piezos you can get regardless of claims to the contrary. The Zomax HP100s I use in the Boominator simply are the best piezo horns I have ever heard. It beats every Motorola horn by a mile. You can get even better ones though but those are dedicated horn drivers that need a (normally threaded) horn, and at a very different price point.
Btw, you do know that with your amp and 2 7Ah SLA in series for 24V you'll only get around 2½-3 hours playing time max, right?
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Saturnus, that sounds like a very good experiment. I'll definitely try it out blind then again with an SPL meter to see. I think I get what you are talking about though. Lower frequencies have to be much louder to be audible in general. Then you add in the great outdoors where low frequencies float away. Outdoor concerts probably boost the lower frequencies quite a bit to achieve nice bass which requires some big time amplification.
interesting design: congratulations
I really like this boominator. I can't stand loud music, but if you are going
to listen to loud music, outside is the place to do it.
I have read that sealed boxes really do not give up anything in bass to ported, it is just that they do not go as low or drop off so quickly below F3. And the
boxes can be about half the size. Maybe we have given up too quickly on the
sealed box?
I am interested in portable battery powered sound reinforcement so that bands do not have to mess with cords and generators. If they do not want to be stupid loud, it seems like your box would work well. Well I appreciate the long run times of your system, it seems like with more power the same
box could go alot louder, although for shorter periods. I do understand what doubling drivers does for efficiency for both the speakers and for the amps (non-tube).
As cheap and light as amps and batteries are (compared to drivers and boxes), would it not be lighter and louder to use fewer drivers and more
watts and batteries?
Would not fold out wings help greatly with reinforcement?
In colorado (and elsewhere in the u.s.) we have the Fat Tire bike rallies .
It started in Ft. Collins (where I live and where the brewery that hosts are).
Upwards of 12,000 people rode in the last bike parade here. Sheer genius on the part of the brewery to get people to do their advertising for them!
Alot of the the people strive to create battery powered PAs for their bikes, but i haven't seen anything really outstanding. http://www.newbelgium.com/tour-de-fat
If you could market your new model, what would you ask for it? I wish I could help fund your project; you are really doing a great job. Maybe some day you could market a upgraded model with a tube preamp and / or tube amplifier from doc bottlehead or Dodd audio.
best wishes
and all respect david sundby sundbyd2@gmail.com
I really like this boominator. I can't stand loud music, but if you are going
to listen to loud music, outside is the place to do it.
I have read that sealed boxes really do not give up anything in bass to ported, it is just that they do not go as low or drop off so quickly below F3. And the
boxes can be about half the size. Maybe we have given up too quickly on the
sealed box?
I am interested in portable battery powered sound reinforcement so that bands do not have to mess with cords and generators. If they do not want to be stupid loud, it seems like your box would work well. Well I appreciate the long run times of your system, it seems like with more power the same
box could go alot louder, although for shorter periods. I do understand what doubling drivers does for efficiency for both the speakers and for the amps (non-tube).
As cheap and light as amps and batteries are (compared to drivers and boxes), would it not be lighter and louder to use fewer drivers and more
watts and batteries?
Would not fold out wings help greatly with reinforcement?
In colorado (and elsewhere in the u.s.) we have the Fat Tire bike rallies .
It started in Ft. Collins (where I live and where the brewery that hosts are).
Upwards of 12,000 people rode in the last bike parade here. Sheer genius on the part of the brewery to get people to do their advertising for them!
Alot of the the people strive to create battery powered PAs for their bikes, but i haven't seen anything really outstanding. http://www.newbelgium.com/tour-de-fat
If you could market your new model, what would you ask for it? I wish I could help fund your project; you are really doing a great job. Maybe some day you could market a upgraded model with a tube preamp and / or tube amplifier from doc bottlehead or Dodd audio.
best wishes
and all respect david sundby sundbyd2@gmail.com
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Hi Guys,
I have built my own mini boominator.
Here is the build thread.
http://www.diyaudio.com/forums/showthread.php?p=1939971#post1939971
I have built my own mini boominator.
An externally hosted image should be here but it was not working when we last tested it.
Here is the build thread.
http://www.diyaudio.com/forums/showthread.php?p=1939971#post1939971
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I'm going to use a amp9 with a active crossover too, although with two fullrange sats and a DVC sub.
You're right in what you're saying about the F3 and the steeper rolloff, but as far as I remember the ported box gives +3dB vs. sealed because of the inverted phase sound is being let out also and not just converted to heat as in a sealed box.
I might be wrong so someone comment please
.The sealed box has lower latency than a ported and not as high phase shift. It is often regarded more accurate and "faster" than a ported speaker (although IMO because of the many faulty port constructions making one note bass, port noise, being used below the Fs etc.).
For outdoor use I believe ported has been used to gain the most dB @ 1watt, but maybe saturnus has a better answer?
Completed my version of the boominator. Still waiting on my Sure 2*100 though.
Despite the lack of an amp, I did have a few sessions with a full size HT receiver to really see what it is made of. I ran into some limits at the very high end that I'd like your advice on.
When pushing it in the 105-108db range, certain music selections with heavier bass seemed to distort (Rap music). I believe I was pushing the speakers past their excursion limits (xmax=2mm). Turning it down a notch for these selections kept them operating normally.
Here is what my cone displacement looks like at my current current tuning.
It is hard to see in this image, but anything past the 2mm is slightly greyed out so at this power output I would be pushing past the limit in the 100hz range then again at 50hz. I have no idea which frequency was causing the problem, but potentially both.
And SPL response:
I don't have any high pass filters or other crossovers. Just the woofer and Motorolla Piezo. Bumping up the tuning frequency to 75hz or 85hz seems to help with the spike at 100hz but I hit xmax much sooner at the low end.
Should I be tuning a little higher and adding a high pass filter to protect the woofers from anything below 60-70hz? I hate to do this cause this only poses a problem when playing at absolute extreme volumes. At normal listening levels, it doesn't have any problem with excursion. Am I missing something else here?
More details about the woofer and enclosure.
Driver Properties
Name: GW-1058
Type: Standard one-way driver
Company: Goldwood
Comment: Pro series
No. of Drivers = 1
Fs = 43.4 Hz
Qms = 2.696
Vas = 2.249 cu.ft
Cms = 0.359 mm/N
Mms = 37.39 g
Rms = 3.79 kg/s
Xmax = 2 mm
Xmech = 3 mm
P-Dia = 212.1 mm
Sd = 355.4 sq.cm
P-Vd = 0.0707 liters
Qes = 0.459
Le = 0.282 mH
Z = 8 ohms
BL = 10.83 N/A
Pe = 180 watts
Qts = 0.392
no = 1.093 %
1-W SPL = 94 dB
-----------------------------------------
Box Properties
Name:
Type: Vented Box
Shape: Prism, square
Vb = 22 liters
Fb = 65 Hz
F3 = 66.89 Hz
Fill = minimal
No. of Vents = 1
Vent shape =
Vent ends =
An externally hosted image should be here but it was not working when we last tested it.
Despite the lack of an amp, I did have a few sessions with a full size HT receiver to really see what it is made of. I ran into some limits at the very high end that I'd like your advice on.
When pushing it in the 105-108db range, certain music selections with heavier bass seemed to distort (Rap music). I believe I was pushing the speakers past their excursion limits (xmax=2mm). Turning it down a notch for these selections kept them operating normally.
Here is what my cone displacement looks like at my current current tuning.
An externally hosted image should be here but it was not working when we last tested it.
It is hard to see in this image, but anything past the 2mm is slightly greyed out so at this power output I would be pushing past the limit in the 100hz range then again at 50hz. I have no idea which frequency was causing the problem, but potentially both.
And SPL response:
An externally hosted image should be here but it was not working when we last tested it.
I don't have any high pass filters or other crossovers. Just the woofer and Motorolla Piezo. Bumping up the tuning frequency to 75hz or 85hz seems to help with the spike at 100hz but I hit xmax much sooner at the low end.
An externally hosted image should be here but it was not working when we last tested it.
Should I be tuning a little higher and adding a high pass filter to protect the woofers from anything below 60-70hz? I hate to do this cause this only poses a problem when playing at absolute extreme volumes. At normal listening levels, it doesn't have any problem with excursion. Am I missing something else here?
More details about the woofer and enclosure.
Driver Properties
Name: GW-1058
Type: Standard one-way driver
Company: Goldwood
Comment: Pro series
No. of Drivers = 1
Fs = 43.4 Hz
Qms = 2.696
Vas = 2.249 cu.ft
Cms = 0.359 mm/N
Mms = 37.39 g
Rms = 3.79 kg/s
Xmax = 2 mm
Xmech = 3 mm
P-Dia = 212.1 mm
Sd = 355.4 sq.cm
P-Vd = 0.0707 liters
Qes = 0.459
Le = 0.282 mH
Z = 8 ohms
BL = 10.83 N/A
Pe = 180 watts
Qts = 0.392
no = 1.093 %
1-W SPL = 94 dB
-----------------------------------------
Box Properties
Name:
Type: Vented Box
Shape: Prism, square
Vb = 22 liters
Fb = 65 Hz
F3 = 66.89 Hz
Fill = minimal
No. of Vents = 1
Vent shape =
Vent ends =
That's pretty easy to calculate actually.
fc = 1 / (2 x pi x F x Z)
fc = corner frequency
F = capacitance in Farads
Z = input impedance in Ohms
It's definitely replacing the 2.2uF capacitor as that's way too big.
As far as I can see the sure boards have 22K to 47K Ohm input impedance, set by the gain switches. If we assume you want the 22K Ohm option for best performance with an mp3player (especially iPods) the replacement input capacitor should be 0.15uF (which puts it in the realm of ultra high quality low voltage SMD capacitors*) for a 48Hz cut-off.
*As a side note I have always had great difficulty in understanding why people would want to chose very large (and noisy) high voltage capacitors made for speaker filters as input capacitors when the needed voltage range would hardly ever be more than a few volts.
fc = 1 / (2 x pi x F x Z)
fc = corner frequency
F = capacitance in Farads
Z = input impedance in Ohms
It's definitely replacing the 2.2uF capacitor as that's way too big.
As far as I can see the sure boards have 22K to 47K Ohm input impedance, set by the gain switches. If we assume you want the 22K Ohm option for best performance with an mp3player (especially iPods) the replacement input capacitor should be 0.15uF (which puts it in the realm of ultra high quality low voltage SMD capacitors*) for a 48Hz cut-off.
*As a side note I have always had great difficulty in understanding why people would want to chose very large (and noisy) high voltage capacitors made for speaker filters as input capacitors when the needed voltage range would hardly ever be more than a few volts.
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Thanks Saturnus. I've been thinking about making the amp portion of this somewhat modular so I could take it out and use it with a different set of full range speakers indoors. In this case, could I move the high pass function between the amp and the speakers rather than modifying the amp directly?
And if so, is it true that I'd use the same formula but solve using an impedance of 8 ohms rather than 22k ohms?
And if so, is it true that I'd use the same formula but solve using an impedance of 8 ohms rather than 22k ohms?
Well, yes and no. Theorically it's possible but it would make the cap much much too big to be practically possible, ie. 680uF for 50Hz cut-off.
But you say full-range speakers, right? Why do you think they wouldn't benefit from the same cut-off? I use a 50Hz cut-off on my Fostex 207Es to keep cone excursion acceptable below the back loaded horn cut-off.
Any full-range speaker is a non-closed cabinet, ie. ported, horn loaded, infinite baffle etc etc will benefit from the same cut-off to limit cone excursion.
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After a whole lot of reading on Passive Crossovers, Capacitor and Coil Calculator, your response makes a lot more sense. I get it. I'll go your route with an input cap.
You mentioned not to mess with the higher voltage caps and to stick with lower voltage SMD ones. I also assume a lower Tolerance is better?
Do any of these make more sense than the other?
Capacitors from Allied Electronics
It doesn't seem like the lower voltage ones come in a 5% tolerance.
You mentioned not to mess with the higher voltage caps and to stick with lower voltage SMD ones. I also assume a lower Tolerance is better?
Do any of these make more sense than the other?
Capacitors from Allied Electronics
It doesn't seem like the lower voltage ones come in a 5% tolerance.