Wood working and safety
===========================
Yes power tools are very powerful - quick. Working already on some much cheaper experiments, I got some free blocks of wood from a local saw mill. Just drive up, and go in the scrap pile. So I hollowed about four blocks out and carefully made the chamber as big as I could get it. Sanded them round all corners and mounted other speakers I reclaimed from sources like computer speakers, clock radios, boom boxes. A pair of acoustic research 3" sound and look alright. However, the drilling process tuned me into the fact about power tools. The drill slipped out while I was carving and caught the pants leg. Less than a second, tore the jeans, and started on the leg muscle. It is still red. So, I understand you. I will keep a very keen discipline while sawing. About the most dangerous thing I might attempt to do is rip 8 1" boards in half to make a lighter outside covering.
So I form the following precepts.
1) know if power is on or off always.
2) Plan cuts and steady - no quick chops
3) observe and act orderly when using these tools
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Q5 - optional discussion off topic some.
Does covering the box with 1/4 hardwood affect anything.
I was going also to add solid rubber tires with two dull
points on the front. Advice? You know, the after things which
are added later. Obviously first they will be jamming.
============================================================
Q6 - Padding
I read some things from the encyclopedia (sponges, neoprene, foam, acoustical padding, etc )/ Foams like Melamine foam seem a good choice because they are open cell foam. I understand that the open cells absorb the sound because of its cavity. Within the manufacturing process, a type of randomness occurs which makes it usable and more covering in its attempt. I perceived from this, that perhaps stretching the material slightly in some areas would increase cavities within the area expanded while smooshing it dense in some areas to obscure some of the cells. Probably not important really, just logically curious.
My final thoughts were to buy acoustical egg shell padding for ceiling tiles, 12" x 12" and use that inside.
Is using acoustical egg shell padding better than polyfill?
==============================================================
Q7 - front baffle - mounting the speaker
The speakers I have have the gasket in front of the metal frame. So the
speaker should be mounted totally inside the cabinet. Do you put braces around
the woofer and drill from the front?
What is the best way to mount and build the mounting for the speaker?
==============================================================
Q8 - front baffel covering - exterior
I did already order a blue cloth grill. My thoughts were to line the front with a hard wood. A nice touch I learned on how to bring out patterns in the grain might affect the sound, hopefully in a positive manner. That is, making the driver ports, woofer, mids, and tweeter, flare outwards. Probably more decorative, the type of sanding along the grain curves embellishes the wood grain signatures to irregular aspects of projection. That is, the grain seems to shoot out from the hole
in a pattern that is along the edge of the driver hole.
Does flaring the driver hole change loudness or sound too much?
===========================
Yes power tools are very powerful - quick. Working already on some much cheaper experiments, I got some free blocks of wood from a local saw mill. Just drive up, and go in the scrap pile. So I hollowed about four blocks out and carefully made the chamber as big as I could get it. Sanded them round all corners and mounted other speakers I reclaimed from sources like computer speakers, clock radios, boom boxes. A pair of acoustic research 3" sound and look alright. However, the drilling process tuned me into the fact about power tools. The drill slipped out while I was carving and caught the pants leg. Less than a second, tore the jeans, and started on the leg muscle. It is still red. So, I understand you. I will keep a very keen discipline while sawing. About the most dangerous thing I might attempt to do is rip 8 1" boards in half to make a lighter outside covering.
So I form the following precepts.
1) know if power is on or off always.
2) Plan cuts and steady - no quick chops
3) observe and act orderly when using these tools
============================================================
Q5 - optional discussion off topic some.
Does covering the box with 1/4 hardwood affect anything.
I was going also to add solid rubber tires with two dull
points on the front. Advice? You know, the after things which
are added later. Obviously first they will be jamming.
============================================================
Q6 - Padding
I read some things from the encyclopedia (sponges, neoprene, foam, acoustical padding, etc )/ Foams like Melamine foam seem a good choice because they are open cell foam. I understand that the open cells absorb the sound because of its cavity. Within the manufacturing process, a type of randomness occurs which makes it usable and more covering in its attempt. I perceived from this, that perhaps stretching the material slightly in some areas would increase cavities within the area expanded while smooshing it dense in some areas to obscure some of the cells. Probably not important really, just logically curious.
My final thoughts were to buy acoustical egg shell padding for ceiling tiles, 12" x 12" and use that inside.
Is using acoustical egg shell padding better than polyfill?
==============================================================
Q7 - front baffle - mounting the speaker
The speakers I have have the gasket in front of the metal frame. So the
speaker should be mounted totally inside the cabinet. Do you put braces around
the woofer and drill from the front?
What is the best way to mount and build the mounting for the speaker?
==============================================================
Q8 - front baffel covering - exterior
I did already order a blue cloth grill. My thoughts were to line the front with a hard wood. A nice touch I learned on how to bring out patterns in the grain might affect the sound, hopefully in a positive manner. That is, making the driver ports, woofer, mids, and tweeter, flare outwards. Probably more decorative, the type of sanding along the grain curves embellishes the wood grain signatures to irregular aspects of projection. That is, the grain seems to shoot out from the hole
in a pattern that is along the edge of the driver hole.
Does flaring the driver hole change loudness or sound too much?
Allen, yes, I wondered about that, I can't find anything relating saturation to the shape of the core.
Anthony, Re: workshop safety, there are plenty of youtube videos on how to use tools safely, watch a few. Then watch a few more. In the workshop, work slowly and methodically, thinking each step through, before you turn on the power
Anthony, Re: workshop safety, there are plenty of youtube videos on how to use tools safely, watch a few. Then watch a few more. In the workshop, work slowly and methodically, thinking each step through, before you turn on the power
IRRC the late G.R. Koonce had an inductor test survey in "Speaker "Builder" but don't remember if laminated steel I-core were included or not (?). (ferrite core fared poor at higher levels)
The late-great DJK said at high levels found in PA work, a 500 watt rating on an I-core inductor was meaningless as heat from the saturated core/IR wire losses could melt the plastic bobbin and burn off the varnish.
Also, DJK made a remark where he thought an I-core laminated steel inductor was superior to the dumbbell type.
There's some trick which can be done placing two I-core inductors end to end - but can't remember so would have to search.
The late-great DJK said at high levels found in PA work, a 500 watt rating on an I-core inductor was meaningless as heat from the saturated core/IR wire losses could melt the plastic bobbin and burn off the varnish.
Also, DJK made a remark where he thought an I-core laminated steel inductor was superior to the dumbbell type.
There's some trick which can be done placing two I-core inductors end to end - but can't remember so would have to search.
Attachments
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Well this was the context:
To the above I opined yes, and no saturation issues with an open type core. I still maintain the same answer.
The shape tells us if the core is an open-type (I, U etc.) or closed. (UU,EE,toroid etc.). Open types complete the flux path through a large airgap (low permeability). Hence, they're less likely to saturate.
Freddi, copper losses (I2R) are different from the core losses that consist of hysteresis and eddy current losses. In the OP's case (100W), even air core inductors would pass with flying colours.
So, on the whole, I think there's absolutely nothing to worry about.
yes, exactly - those eights.
--------------------------------
I like how the eight sounds, its a good level but lacks detail in mid range. Perhaps with those drivers, a better tweeter. Mainly, I was going to make them for a neighborhood sale where those would be part of the high end act. So I do live behind a thrift store and have captured a plethora of cheap "decent" drivers for radios and such.
Most of what I have found deserve to live as an audio component. While I did work and bought the previous drivers, these are also good. So I have started construction on several sets. Without parameters, it is difficult to be accurate for box. This allows for experimentation of size using slapped together stuff. It always seems that the original box for most are way too small for a nice build (like four inches). As well adding tweeters to the drivers which have a decent x max and foam surround adds a nice touch to allowing people to enjoy them. That is, with the added speakers, tweeters and inexpensive 2 way cross overs, they will be a more enjoyed by people for the added sound quality.
My main packaging issue is having a portable solution that powers these 4", 5", and 3" <50 watt amp. And do this cost effectively. Well because when you sell to you neighbor, there is not as much emphasis on the boosted prophet but rather decent sound and looks.
So my mini project consists of about 6 pair of speakers, now seven for the nice 8". Its so fun to dream about even more. In the future, I will not take apart the cheap stuff and just stick with a good design. That is once, I learn more about everything from this marvelous audio communication portal.
Question, I did get an interesting speaker, it was build well and had some morse drivers in it. They were labeled as a monitor speaker The eight " driver for this speaker, was a 35watt morse driver. Inside a termendious cabinet, with a dual lpad, two 4ohm morse midranges wired in series. Under the midranges were "leaky ports I think" or just bad build?. The 8" was complimented by a 10" passive radiator. A threeway cross over.
The 8" burned up in the voice coil, ? Can you fix this as a interesting hobby part, the foam, paper, and voice coil? Seems cool, but those drivers any good or another 8" just as good.
Anyone what to take a look at each of these drivers in pictures? Perhaps to help guess estimate a box size for them.
My experimentation speaker bin includes -
1 altec landsing 40w 4" woofer,
1 nascoo 40w 4" woofer
2 altec landing 3" woofers
2 sony 20watt 5" full range woofer
2 sony 25watt 4" woofer
4 sony 3" 10 watts 4 ohm (boom box speakers), low excursion.
for these speakers using these drivers, I plan to use a 2way cross over. But I know that a capacitor could be used.
So for my offering of these lovelies, I will
make each a suitable multidriver unit. and add 2way tweeter. I have some ces 1/2" mylar domes I will put with them.
Make them look good with hardwood covering the outside.
All new grill covers.
--------------------------------
I like how the eight sounds, its a good level but lacks detail in mid range. Perhaps with those drivers, a better tweeter. Mainly, I was going to make them for a neighborhood sale where those would be part of the high end act. So I do live behind a thrift store and have captured a plethora of cheap "decent" drivers for radios and such.
Most of what I have found deserve to live as an audio component. While I did work and bought the previous drivers, these are also good. So I have started construction on several sets. Without parameters, it is difficult to be accurate for box. This allows for experimentation of size using slapped together stuff. It always seems that the original box for most are way too small for a nice build (like four inches). As well adding tweeters to the drivers which have a decent x max and foam surround adds a nice touch to allowing people to enjoy them. That is, with the added speakers, tweeters and inexpensive 2 way cross overs, they will be a more enjoyed by people for the added sound quality.
My main packaging issue is having a portable solution that powers these 4", 5", and 3" <50 watt amp. And do this cost effectively. Well because when you sell to you neighbor, there is not as much emphasis on the boosted prophet but rather decent sound and looks.
So my mini project consists of about 6 pair of speakers, now seven for the nice 8". Its so fun to dream about even more. In the future, I will not take apart the cheap stuff and just stick with a good design. That is once, I learn more about everything from this marvelous audio communication portal.
Question, I did get an interesting speaker, it was build well and had some morse drivers in it. They were labeled as a monitor speaker The eight " driver for this speaker, was a 35watt morse driver. Inside a termendious cabinet, with a dual lpad, two 4ohm morse midranges wired in series. Under the midranges were "leaky ports I think" or just bad build?. The 8" was complimented by a 10" passive radiator. A threeway cross over.
The 8" burned up in the voice coil, ? Can you fix this as a interesting hobby part, the foam, paper, and voice coil? Seems cool, but those drivers any good or another 8" just as good.
Anyone what to take a look at each of these drivers in pictures? Perhaps to help guess estimate a box size for them.
My experimentation speaker bin includes -
1 altec landsing 40w 4" woofer,
1 nascoo 40w 4" woofer
2 altec landing 3" woofers
2 sony 20watt 5" full range woofer
2 sony 25watt 4" woofer
4 sony 3" 10 watts 4 ohm (boom box speakers), low excursion.
for these speakers using these drivers, I plan to use a 2way cross over. But I know that a capacitor could be used.
So for my offering of these lovelies, I will
make each a suitable multidriver unit. and add 2way tweeter. I have some ces 1/2" mylar domes I will put with them.
Make them look good with hardwood covering the outside.
All new grill covers.
Maybe words are getting in the way..
Cores can saturate regardless of whether they are a closed loop or not. It is a matter of when in any case. There is more to the situation than just the shape of the core. Eg the number of turns and the size of the core are just some.
A person ought to measure a plot such as inductance vs current if they want to assess saturation. Often in regards to inductors there is very little data, and when there is it is usually insufficient, even from some manufacturers, not to mention difficult to relate to a realistic situation. Such a situation might be improved with simulation of the individual circuit it is being used in.
Inductors may partially burn, and it can happen underneath where you can't see. It can create a shorted turn.
You might have heard of gapping output transformer cores, there are some differences there compared with speaker inductors.
In case of an I-core (solenoid), a large part (50%) of the magnetic path is through air, making saturation less likely when compared to using steel alone (without gap).
Yes, inductors can burn because of the poor heat ventilation (improper design) from the inner layer windings. However, the proposed Dayton inductors were 18AWG with < 0.5 ohm resistance, whereas the speaker voice coil is at least ten times as resistive.
Yes, the wording could have been better, but at the power level under consideration (100W etc.), any mishap is still very unlikely.
Yes, inductors can burn because of the poor heat ventilation (improper design) from the inner layer windings. However, the proposed Dayton inductors were 18AWG with < 0.5 ohm resistance, whereas the speaker voice coil is at least ten times as resistive.
Yes, the wording could have been better, but at the power level under consideration (100W etc.), any mishap is still very unlikely.
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I agree that it is going to happen at some point. However a gapped core can still saturate before a non-gapped one, since that is only part of the story.
Yes, but that would be at a much higher current, everything else being the same. I wouldn't make any comparisons with air-core inductors that don't saturate.
Please read 'steel' in place of 'ferrite':
Funda of gapped choke
Note the part where it's said how the air gap is left the only significant contributor to overall reluctance.
Please read 'steel' in place of 'ferrite':
Funda of gapped choke
Note the part where it's said how the air gap is left the only significant contributor to overall reluctance.
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Here is the refined parts list for the cross over. A member previously designed these along with the cabinet size, dimensions. The subs are integrated at the 384hz range. It appears that the peizo tweeter is also a standard point. Would anyone recommend different, or more robust components.
parts list with links
=====================
C1 70uf
--------
68uF 100V Electrolytic Non-Polarized Crossover Capacitor
68uF 100V Electrolytic Non-Polarized Crossover Capacitor
and also in parallel
10uF 100V Electrolytic Non-Polarized Crossover Capacitor
10uF 100V Electrolytic Non-Polarized Crossover Capacitor
R1 8.2
-------
8.2 Ohm 10W Resistor Wire Wound 5% Tolerance
Shopping
C2 1.8uF
--------
Jantzen Audio 1.8uF 400V Z-Standard Capacitor
Shopping
R2 22
-----
22 Ohm 10W Resistor Wire Wound 5% Tolerance
Shopping
L1 3.3mH
--------
ERSE Super Q 3.3mH 16 AWG 500W Inductor Crossover Coil
https://www.parts-express.com/ERSE-Super-Q-3.3mH-16-AWG-500W-Inductor-266-914
** this is suggested due to better quality
Alternate but not the best solution
Jantzen Audio 3.3mH 18 AWG Air Core Inductor Crossover Coil
https://www.parts-express.com/Jantzen-1070-3.3mH-18-AWG-Air-Core-Inductor-255-276
L2 .68mH
---------
Jantzen Audio 0.68mH 15 AWG Air Core Inductor Crossover Coil
https://www.parts-express.com/Jantzen-1854-0.68mH-15-AWG-Air-Core-Inductor-255-414
parts list with links
=====================
C1 70uf
--------
68uF 100V Electrolytic Non-Polarized Crossover Capacitor
68uF 100V Electrolytic Non-Polarized Crossover Capacitor
and also in parallel
10uF 100V Electrolytic Non-Polarized Crossover Capacitor
10uF 100V Electrolytic Non-Polarized Crossover Capacitor
R1 8.2
-------
8.2 Ohm 10W Resistor Wire Wound 5% Tolerance
Shopping
C2 1.8uF
--------
Jantzen Audio 1.8uF 400V Z-Standard Capacitor
Shopping
R2 22
-----
22 Ohm 10W Resistor Wire Wound 5% Tolerance
Shopping
L1 3.3mH
--------
ERSE Super Q 3.3mH 16 AWG 500W Inductor Crossover Coil
https://www.parts-express.com/ERSE-Super-Q-3.3mH-16-AWG-500W-Inductor-266-914
** this is suggested due to better quality
Alternate but not the best solution
Jantzen Audio 3.3mH 18 AWG Air Core Inductor Crossover Coil
https://www.parts-express.com/Jantzen-1070-3.3mH-18-AWG-Air-Core-Inductor-255-276
L2 .68mH
---------
Jantzen Audio 0.68mH 15 AWG Air Core Inductor Crossover Coil
https://www.parts-express.com/Jantzen-1854-0.68mH-15-AWG-Air-Core-Inductor-255-414
roger 1.4 cubic ft
Presto! I'll find the parts and do it. Now with two designed, perhaps I'll look a little closer and see the topology and components.
Presto! I'll find the parts and do it. Now with two designed, perhaps I'll look a little closer and see the topology and components.
All parts look good. If only you could use polypropylene (PP) capacitors instead of electrolytic, it would all be much better. Following are examples for affordable PP capacitors from the motor drive industry. They would do much better than the electrolytics in terms of linearity, losses or lifespan.
Motor running capacitor 70uF:
Motor running capacitor 10uF:
All the best.
Motor running capacitor 70uF:
Motor running capacitor 10uF:
All the best.
here's a decent price on a 70uF motor run cap
Motor Start Run Capacitor 70uF MFD 250 Volt A/C 50/60hz Cylindric CBB60 664271223966 | eBay
Motor Start Run Capacitor 70uF MFD 250 Volt A/C 50/60hz Cylindric CBB60 664271223966 | eBay
You may simply pick an 80uF motor capacitor from a local electrical shop instead of having 68uF and 10uF in parallel. The price would be more or less the same.
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