wow - that was a quick reply, and from the master himselfThanks to you Saturnus for coming up with that design!!
No worries. Hope you enjoyed building and using it.
I got Google Alert
What size fuse do I need for 3 x 7ah 12v SLA batteries on Amp6B?
Do I need to change anything to avoid the power-on 'pop' or will it not happen if I keep it muted during power-on?
What size resistors do I need for original ksn-1001a's? (paired with gw-1058's)
I am sorry if these are redundant questions! I simply cannot mine though thousands of posts every time I need to know something. The search function on this site and google's exact phrase search of this site are limited. Hope I'm not beating a dead horse but if the wiki had a few more little nuggets of key info with concise explanations, askers like me could be referred there.
Do I need to change anything to avoid the power-on 'pop' or will it not happen if I keep it muted during power-on?
What size resistors do I need for original ksn-1001a's? (paired with gw-1058's)
I am sorry if these are redundant questions! I simply cannot mine though thousands of posts every time I need to know something. The search function on this site and google's exact phrase search of this site are limited. Hope I'm not beating a dead horse but if the wiki had a few more little nuggets of key info with concise explanations, askers like me could be referred there.
I would use a fuse on each battery, as close as possible to the plus.
10A or 15A should protect the battery's just fine.
I've ordered 2 amorphous 10w solar panels and one regulator. On the input on the reultor I'll connect the panels, of course, but I'd also like to be able to connect a dc transformer, for regular charging. I understand that I'll need a Schottky diode to each panel and one to the dc transformer, but what size?
Could these work? https://www.elfa.se/elfa3~se_en/elfa/init.do?item=70-120-13&toc=18973
Could these work? https://www.elfa.se/elfa3~se_en/elfa/init.do?item=70-120-13&toc=18973
P.Audio will prepare and send me a replacement
PS! Stop using screws when building Boominator
Glue is good enough and easier to cut tru.
Tweeter Diffraction Effects Explanation
This is a really good explanation of tweeter diffraction effects. It explains why the tweeter should be unequal in distance to as many sides of the baffle as possible to reduce frequency response ripples:
Tweeter diffraction
Note that in the Boominator design the distance between the centers of the piezos and the side edge of the baffle is 68mm, which is equal to the wavelength of 5khz, the peak frequency on many piezos including ksn-1001a/5a. This somewhat flattens the response.
This is a really good explanation of tweeter diffraction effects. It explains why the tweeter should be unequal in distance to as many sides of the baffle as possible to reduce frequency response ripples:
Tweeter diffraction
Note that in the Boominator design the distance between the centers of the piezos and the side edge of the baffle is 68mm, which is equal to the wavelength of 5khz, the peak frequency on many piezos including ksn-1001a/5a. This somewhat flattens the response.
In principle, no.
On the Boominator however that implies you're making the reflex port smaller which in turn will increase air speed in the reflex port, so here, yes, it will bring a fair bit of problems.
If you're just making it shorter without decreasing the area then you're making the tuning frequency and Qs much higher which brings many other problems.
In both cases, a basic understanding of how a reflex cabinet works will help you realize what problems and how they can be overcome, so I suggest you search the internet for some information on this, if you want a more thorough explanation.
That is correct. Note also that placement in middle of baffle with 150mm to each side also creates a deeper dip at about 2.3Khz which helps to improve the apparent, or the natural acoustic if you like, filter slope of the tweeters.
Furthermore, having these 2 distances slightly off being exact multiples of each other helps to reduce diffraction ripple at higher frequencies. Here I've used good practice in musical theory and stayed away from the factor relationship between musical notes, square root of 2 times the average distance between half-notes is used to be exact. I have in other designs found this to give the best result, and better than "golden ratio" in fact. Here it would probably have no significant effect if it's slightly off but it's considered in the design at least.
It's important to note that with diffraction like other inherent acoustical phenomena, you can either try to reduce or eliminate the effect, or exploit them to your advantage. The latter naturally requires exact knowledge of why and how you're doing it to give a positive result.
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Sorry that should read: the average distance between half-notes divided with the square root of 2, not multiplied by it.
How do I calculate what size to put on the input cap on the AMP6?
fc = 1 / (2 x pi x F x Z)
fc = corner frequency
F = capacitance in Farads
Z = input impedance in Ohms
I saw this earlier in the thread and tried to apply my values. I've got 22kOhm input resistors and 82kOhm feedback resistors. Am I supposed to put 22kOhm as Z?
This gives me an F at 0,09F but another builder got 0,47F. What am I doing wrong?
fc = 1 / (2 x pi x F x Z)
fc = corner frequency
F = capacitance in Farads
Z = input impedance in Ohms
I saw this earlier in the thread and tried to apply my values. I've got 22kOhm input resistors and 82kOhm feedback resistors. Am I supposed to put 22kOhm as Z?
This gives me an F at 0,09F but another builder got 0,47F. What am I doing wrong?
That's a mighty big cap _D
It's supposed to be 0,470uF or 470nF. That's 470-billionth of a Farad. The u stands for micro (a millionth) and n stands for nano (a billionth).
A 470nF cap will give an Fc of 15Hz. However, the filtering will due to the low Q already start at about 63Hz which is perfect for this use.
Of course it's supposed to read 0,47uF, a slight typo
Perfect! Then I believe I've got everything in order, will hopefully start building next weekend
The version where the speaker chambers are tilted 90 degrees so they are vertical instead of horizontal, resulting in a taller and narrower box - does it affect sound or anything?
Is it ok to use a 1/2" roundover bit on the inside/outside of the ports and edges of the box in addition to the speaker holes? or should they have a smaller radius curve..
Is it ok to use a 1/2" roundover bit on the inside/outside of the ports and edges of the box in addition to the speaker holes? or should they have a smaller radius curve..
Hahaha I didn't even think of that when I cut mine out, as I cut them out dead centre of the sides, but forgetting that I increased the center pocket to fit wider batteries so the boomer ended up 12mm taller, so the handles are 12mm offset.
But, as it is, this is only the second 'wood' pair of enclosures I have built , I would not be able to answer your questions, sorry.
S.
Think of it differently. The fuses on the battery does not protect your amp but your batteries and indeed your entire system from a short circuit.
The recommended value is between the maximum current draw of the system and the peak discharge of the batteries. Each battery "cell group" should be fused individually where cell group means any number of cells in series.
Changing the input cap to a 470nF WIMA cap (part no. MKS0C034700E00) which fits in the original hole pitch of 2.54mm (1/10") will both improve sound quality and completely eliminate power-on pops.
It will not however remove thumps and pops if you change input while the amp is on. For that you need an arrangement of an external input with insertion sensor. For example, an open-back mini-jack socket with a micro-switch arranged to switch on (also called normally open switch) when a mini-jack plug is inserted. This is best connected to the AWAKE pin so that it effectively and immediately puts the amp in and out of sleep mode when a mini-jack is inserted or removed.
This also eliminates the need for an additional power switch as power drain of the TS2020 in sleep mode is 2.5uA. Or in other words, so little it would take over 2½ years to discharge a single 12V 7Ah SLA.
33 ohm with the original CTS piezoes (capacitance is higher than on the replicas so a smaller resistor is needed to achieve the same result).
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Reflex ports works best, or at least most optimally according to theory, when symmetrically loaded. However, that is not the only reason. The ends needs additional bracing in the middle, so it's obviously more productive to fuse the two and use the needed brace as part of a theoretically optimal port structure.