What are people using to seal wiring where it passes through internal chambers? I have some nylon weather-tight strain reliefs but they seem like a real pain to use here!
Head off to the stationary store (or department) and get some "Tack&Stick" ... the stuff they use for putting up temporary posters. I'ts a very gooey putty like material you can mould and press into the opening. It never sets up hard and comes out nice and easy if you ever need to move or replace the wires.
Are you familiar with duct seal (the grey play dough type that looks like plastic explosives from the movies)? I wonder how it would work here? Just trying to avoid going shopping and catching the plague.
First, if the holes aren't huge, I wouldn't even bother sealing them up. They're internal and it's unlikely enough air would pass to do any damage.
Second, no. Sorry.
Hi jwilhelm,
I have used the product you mentioned or a product like it. The product I have is plumbers putty and it works okay but does dry out of time and turns somewhat brittle.
Have Fun,
Rich
I have used the product you mentioned or a product like it. The product I have is plumbers putty and it works okay but does dry out of time and turns somewhat brittle.
Have Fun,
Rich
I'm familiar with plumbers putty. It's pretty greasy and yes it does dry out. The stuff I'm thinking of is what electricians and plumbers use when they need to bring a pipe through an exterior wall. It stays pliable for ever. I'll likely use TEW to wire the drivers so I could just drill holes close the the exact diameter and use a little silicone.
Sounds to me like a sound plan. I've used the clear silicone successfully. No problems at all.
Best,
Rich
Best,
Rich
@Douglas Blake,
I took a quick peek at your xover design this morning before heading off to work and I must say it will be difficult to improve upon without throwing more components into the mix. Very nice that you to come up with something so tight in such a brief time.😀 I really like your less is more design philosophy.
Have a great day,
Rich
I took a quick peek at your xover design this morning before heading off to work and I must say it will be difficult to improve upon without throwing more components into the mix. Very nice that you to come up with something so tight in such a brief time.😀 I really like your less is more design philosophy.
Have a great day,
Rich
i like douglas blake's idea monitoring the current draw in crossover design and take it into account, but what sound benefits are there?
Thank you, Rich 🙂
I think I'm a little different than most people on this point...
When I see something that appears more complex than it needs to be, it always crosses my mind that either the person doesn't really know what they are doing or that they are too lazy to refine their designs.
PS Audio's $2,500 phono stage is a first class example. In the 1970s we were building magnetic phono preamps with a single 8 pin dual op-amp and getting perfectly good results. But now... THIS ... 700 parts for something I can do with fewer than 40, and usually for under $30.00. This, to me, is the very personification of incompetence.
When in training I was constantly heckled to first get the thing to work at all, then take out everything that wasn't needed to make it work properly. Seemed like a pretty good idea, so I stayed with it.
You get a speaker that sounds lively, much more present and scales well with power and volume changes. In essence you set the drivers free to do their jobs.
Many of today's speakers just don't "get up and dance" like the older L-100s or Heresys did... they sound constrained, limited and often very weak at reasonable volumes. This drives demand for more power and in the end just uses up a whole lot more electricity to accomplish less. In most cases, this is because a considerable amount of the amplifier's energy is being routed to ground, not to the drivers.
It's like driving your car with the emergency brake on... All the "get up and go", got up and went.
Plus your amplifiers run cooler, you need less power and you save on electricity.
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It looks like squawker (midrange) breakup modes would only be 13-18 dB down in the current design, while they may seemingly be audible as far down as 27 dB in some cases. Adding one or two parts to form a little notch in the 6-10 kHz region may thus turn out to be a good idea.
Insufficiently suppressed breakup modes tend to result in mysteriously "harsh" sound when there is barely a blip on the frequency response graph.
Insufficiently suppressed breakup modes tend to result in mysteriously "harsh" sound when there is barely a blip on the frequency response graph.
That isn't an especially bad breakup, not like the woofer's. Some minor trimming of L2 and C3 can improve it a bit, but at the expense of more wasted current. I doubt it would be all that audible. But I will look into this on the next design iteration.
Thank you.
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It does look fairly well-behaved for a metal cone, but I'm not sure whether the manufacturer-provided response can be trusted 100% in this respect. (One reviewer called the driver "shrill". Well, duh, it's intended as a midwoofer, not a fullrange. Metal cones generally need some more attention.)
BTW, it's too late now but the tweeter is also available in a truncated faceplate version that would have permitted closer midrange-tweeter spacing. A waveguide would have been nice, too, but I don't see too many good candidates at Parts Express.
BTW, it's too late now but the tweeter is also available in a truncated faceplate version that would have permitted closer midrange-tweeter spacing. A waveguide would have been nice, too, but I don't see too many good candidates at Parts Express.
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Don't forget this is a preliminary design, intended to establish a topology (general schematic) that will have to be refined once we have actual driver measurements. I'm sure that once we get to that, things will change.
I was originally planning to loose the tweeter face completely and rear mount it closer to the woofer but I don't think she would have liked the appearance.
I don't really trust the manufactures specs either, these are pretty inexpensive so likely tolerances aren't very tight in production. I'll be taking proper measurements with some guidance from the forum once I have drivers in the cabinets and have a chance to break them in.
I don't really trust the manufactures specs either, these are pretty inexpensive so likely tolerances aren't very tight in production. I'll be taking proper measurements with some guidance from the forum once I have drivers in the cabinets and have a chance to break them in.
It would also complicate service if the tweeter ever needed replacing.
(The technician in me thinks about stuff like that....)
I thought of that too. I was originally planning to mount the woofers in the wood front baffles (spaced forward) and have the aluminum front as a bolt on grill that covered the edges of the drivers hiding all the fasteners, but dropped that idea with the rear mounted tweeter.
The tweeter design kind of sucks mechanically. The wire connections stick way out into the mounting surface so by the time clearance is added for the wire connections there isn't a lot of sealing surface left. I realize the tweeter is a sealed unit but it mounts in the midrange cavity and may have leakage issues.
The tweeter design kind of sucks mechanically. The wire connections stick way out into the mounting surface so by the time clearance is added for the wire connections there isn't a lot of sealing surface left. I realize the tweeter is a sealed unit but it mounts in the midrange cavity and may have leakage issues.
Not entirely analogous, but ... when I replace a tweeter (which I've done far too often for people who keep saying: "I'm sorry, what did you say" 🙂 ) I will cut a small neoprene gasket that sits between the tweeter surround and the cabinet. I don't know how much difference it really makes but it does seem to make sense.
