Matt
As I said in my reply, some values have changed a little, but you claim to have .9 mH inductors when Madisound says that they sent you .6 mH inductors. Somebody is upside down.
There was one resistor missing and the Madisound shipping docs confirm this. I'll send those out to you. Otherwise your list is correct.
As I said in my reply, some values have changed a little, but you claim to have .9 mH inductors when Madisound says that they sent you .6 mH inductors. Somebody is upside down.
There was one resistor missing and the Madisound shipping docs confirm this. I'll send those out to you. Otherwise your list is correct.
I don't know who the source is, but ok.gedlee said:
Ok as to the values, thanks. You are correct, .6, not .9. I even knew that when I wrote the email, I had corrected myself, but somehow typed .9 anyway. Let's rack it up to working too hard. 40 hour a week job, graduate school, thesis, and finishing these speakers has me upside down.
Thank's for getting back to me, things should be good now. I will double check to be sure, but I think everything is in order.
pjpoes said:
The "source" and I go way back. He never misses the opportunity to harass me. He was the guy who insisted that water was incompressible - you know, infinite velocity of sound. He probably still believes that.
Yes, you have all but the one resistor, which was my error in not ordering it. Sorry about that. I had to change the crossover to get the costs down or I was going to have to increase the kit cost again. The crossover parts keep going up all the time. They are approaching the costs of the drivers - well not the 12TBX100, which is very expensive.
Simplifying the crossover for the Harper was a "must" because those drivers were a lot less expensive and the kit could not afford the same crossover as the bigger models. I think I can do it though. The Harper response is very good (as shown) but its going to have about 10 dB less MAX_SPL than your Abbey's.
As long as they can exceed say 105 db's or so I think they will work fine. No chance they could be made less deep? Or have an appearance that doesn't look too deep, such as for wall mounting?
Oh is there any sort of diagrams for laying out the parts on the rear panels. I'm simply going by a mix of the schematic and looking at the layout in that little picture, but it's not so easy, and I've made a few mistakes already, having to dismount and remount parts.
Oh is there any sort of diagrams for laying out the parts on the rear panels. I'm simply going by a mix of the schematic and looking at the layout in that little picture, but it's not so easy, and I've made a few mistakes already, having to dismount and remount parts.
Markus,
It must be heartbreaking to see those lines appear on your beautiful cabinets.
Since the cabinets are being CNC'd now, maybe it wouldn't be too complicated to mike 45 deg miter joints at the corner.
This would make the end grain, glue absorption, and shrinkage symmetric about the joint line.
All this talk of multiple coatings makes it seems like there must be a better way.
What about polyester resin? It's cheaper than epoxy, and it seems that the painful seal/surface build could be significantly shortened.
Rather than trying to let the MDF drink it's pricey fill, you could let the first application get fairly tacky, by which point I'd think it has stopped moving deeper, and then apply another layer, which may be all it would take to get good surface build and a good sanding base.
Then a top color coat which could be finished to the degree of luster desired.
It must be heartbreaking to see those lines appear on your beautiful cabinets.
Since the cabinets are being CNC'd now, maybe it wouldn't be too complicated to mike 45 deg miter joints at the corner.
This would make the end grain, glue absorption, and shrinkage symmetric about the joint line.
All this talk of multiple coatings makes it seems like there must be a better way.
What about polyester resin? It's cheaper than epoxy, and it seems that the painful seal/surface build could be significantly shortened.
Rather than trying to let the MDF drink it's pricey fill, you could let the first application get fairly tacky, by which point I'd think it has stopped moving deeper, and then apply another layer, which may be all it would take to get good surface build and a good sanding base.
Then a top color coat which could be finished to the degree of luster desired.
To an experienced painter there is no problem here at all. I painted the primer on the Harpers last night - three coats in an evening and its done. A little sanding, maybe another coat, and then color. What we are seeing here is experiment and trial and error and that is always a painful process. As I have said, over and over again, why build the kits yourself? Unless you are very experienced just let an expert do it. If you build them yourself it must be because you like the work, in which case you will cherish the paint process!!!
Dr. Geddes,
"To an experienced painter there is no problem here at all."
Does that include to Markus' problem?
I'm very interested in the Harpers.
Will you be starting a thread soon?
Or if you don't mind, I'd be happy to.
"To an experienced painter there is no problem here at all."
Does that include to Markus' problem?
I'm very interested in the Harpers.
Will you be starting a thread soon?
Or if you don't mind, I'd be happy to.
noah katz said:
Polyester resign with Fiberglass! I think it's brilliant!
Crap stinks to high Haven but that sure will not crack and fiberglass (or better yet, carbon fiber) will go over this corners nice! 2 thumbs up!
Actually I meant just the resin.
Can you really get the fabric to follow the corners?
It sands easily but it might be a bit iffy recovering the corner geometry.
But I guess it would near guaranty against lines appearing.
Actually why not use it for the joints as well?
Does anyone know if polyester is hydrophilic like (I think) epoxy is?
Now that I think about it, how does it work when something waterproof like epoxy is also hydrophilic?
You'd think that means that it would allow some rate of moisture migration through, but maybe it's too low of a rate to be significant.
Can you really get the fabric to follow the corners?
It sands easily but it might be a bit iffy recovering the corner geometry.
But I guess it would near guaranty against lines appearing.
Actually why not use it for the joints as well?
Does anyone know if polyester is hydrophilic like (I think) epoxy is?
Now that I think about it, how does it work when something waterproof like epoxy is also hydrophilic?
You'd think that means that it would allow some rate of moisture migration through, but maybe it's too low of a rate to be significant.
A friend of mine was making custom surfboards in my shop. I got interested in the work and learned a few things from him. It depends of cause on fiberglass but yes, it would conform to this shape. If the resign and fiberglass applied correctly, there's very little sanding involved and best part is, then it's done, IT IS DONE. No more shrinking. Also, you could always apply more resign and sand it.
I've painted a lot of MDF cabinets with lots of different paints. My favs are either Kraylon spray paints for simple jobs or automotive base coat/clear coat over suitable urethane primer. I even have some painted cabinets which were professionally build and painted. One thing in common, butt joints always reveal themselves after a period of time. MDF does not have the same dimensional stability in all 3 dimensions.
john k... I agree, the best painting technique can't keep the MDF from shrinking. Let's see what owners of speakers built by Earl have to report in 3 months 😉
I built a pair of speakers in 2007 from a flatpack kit of cnc'd mdf. After reading this, I got curious about how they are holding up. Maybe it hasn't been enough time, but I see no butt joints. I live near chicago and so they have been through pretty high and very low humidity.
I only painted them with truck bedliner, and there was no primer. I did use a minwax wood filler on all of the joints, which was sanded down. There are certain imperfections where I sanded it insufifciently, but only visiable at the right angle, with the right indirect light, and looking for it pretty close up.
I had demo'd the Nathan's which Earl had built a while ago, and they had no imperfections in this regard either.
I guess what I am saying is that mdf boxes shouldn't necessarily have a problem with this -at least not immediately like these did.
But we will only know for sure as time will tell.
The bedliner was cheap and easy. I will try and do a nicer paint with my kits. Hoping to achieve a nice high gloss black. I have someone that has an in at a body shop once I have them put together they will give me a quote. If that is too expensive, then I may try and do it myself. And if it doesn't work out. I will go back to the bedliner. The finish itself, if you haven't seen it, is a bit grainy charcoal black. It seems to have a little sparkle in it and a little sheen. My wife says she thinks the speakers I built look like a store bought speaker -which was very important to her.
Unfortunately all of my DIY sub boxes are still in raw mdf... and she has been asking when I am going to finish them.
I only painted them with truck bedliner, and there was no primer. I did use a minwax wood filler on all of the joints, which was sanded down. There are certain imperfections where I sanded it insufifciently, but only visiable at the right angle, with the right indirect light, and looking for it pretty close up.
I had demo'd the Nathan's which Earl had built a while ago, and they had no imperfections in this regard either.
I guess what I am saying is that mdf boxes shouldn't necessarily have a problem with this -at least not immediately like these did.
But we will only know for sure as time will tell.
The bedliner was cheap and easy. I will try and do a nicer paint with my kits. Hoping to achieve a nice high gloss black. I have someone that has an in at a body shop once I have them put together they will give me a quote. If that is too expensive, then I may try and do it myself. And if it doesn't work out. I will go back to the bedliner. The finish itself, if you haven't seen it, is a bit grainy charcoal black. It seems to have a little sparkle in it and a little sheen. My wife says she thinks the speakers I built look like a store bought speaker -which was very important to her.
Unfortunately all of my DIY sub boxes are still in raw mdf... and she has been asking when I am going to finish them.
Yes they are all butt joints.
I looked up your Nathan build thread -- did you use that gorilla glue in the picture? I used titebond -which is glue specifically for wood. It may be the key difference.
Also, I remember now that Earl had repainted the demo Nathan's just before he sent them out, so it wouldn't be likely to exhibit this problem that soon.
-Tony
I looked up your Nathan build thread -- did you use that gorilla glue in the picture? I used titebond -which is glue specifically for wood. It may be the key difference.
Also, I remember now that Earl had repainted the demo Nathan's just before he sent them out, so it wouldn't be likely to exhibit this problem that soon.
-Tony
noah katz said:
I didn't know Markus had a problem, but he didn't spray. Or do you mean Matt? Matt's not done yet, so it remains to be seen how things end up. Matt has less than ideal circumstances. I warned him early on that spraying in cold weather was a big problem. I heat my spray booth, and its indoors. The warmer the substrate the better. Many 1st rate finishes are baked right after spaying on warm substrates, although most pros have now gone to powder coating which alleviates all of these issues.
I will start a thread soon on the Harpers, or you are welcome to start one. My website will be soon.
I've tried everything that was mentioned here on fillers including polyurethane plastic mixed with glass fibers as well as glass beads. The glass beads works a lot better. But the Interlux polyester filler works great too right out of the can. Epoxy does not change with moisture, but the MDF will. I also spray the insides of my cabinets to minimize moisture absorption. I have not seen a joint problem with the materials that I use, but these are not common materials. Thin coats and common paints aren't going to hold up I suspect, but the industrial stuff does.
Krylon is just a brand name for Rust-o-leum, but I prefer their industrial line.
TRADERXFAN said:
Tony
But these have come back, repaired and sent out again, and thats been a couple of months. There was no issue with the joints, although I did notice some warps on some of the edges, probably due to filler expansion. I've changed fillers for this reason. The new Interlux stuff seems to work great. We'll see.
I don't recommend the polyurethane glue anymore because the titebond stuff is more stable. Live and learn.
TRADERXFAN said:
I used Gorilla Wood Glue. I think using too much water based stuff in a too short time on not very dense MDF caused the shrinkage on my Nathans.
Earl, I think you didn't see the picture I posted in #150 after editing the post.
Ok well I'll openly post my new problem here. When I first assembled the enclosures there was some slight fit issues with the rear panels, but at the time it appears to just need some sanding and squaring up of the opening. I now see that what wasn't fitting was not what I thought. It's the constrained layer pieces, which are too wide for the opening of the baluns. I thought it was minor, the thickness of the paint and glue maybe. However it's not, its much thicker, it's more like 1/8" on every side. If there is any recommendation on how to fix this, I would appreciate it. At this point I think my best bet is to remove all of the crossover parts (oh what a paint) and use the router to trim down the pieces. Trimming the baluns I think will be more work as they all have nails in them and I would have to cut down the nails as well. This might be the better option though.
Dr. Geddes, I can't imagine this is just an assembly issue on my part. What do you do during assembly to ensure they fit. What do you do if they don't? Another thing I've noticed that is compounding the fit issue is that the constrained layer pieces are ever so slightly not square on the panel. Have you noticed this ever before?
Dr. Geddes, I can't imagine this is just an assembly issue on my part. What do you do during assembly to ensure they fit. What do you do if they don't? Another thing I've noticed that is compounding the fit issue is that the constrained layer pieces are ever so slightly not square on the panel. Have you noticed this ever before?
Quick question to builders.
Do you guys ever consider putting an additional joints in MDF, like spline or a few biscuits?
Do you guys ever consider putting an additional joints in MDF, like spline or a few biscuits?