My Mini Statement Build

[Mike82]

I started working on this the other day and decided to start posting it here. Here are some pictures of what i have done so far.


Images not available

[ThomasW]

Unless you're going to rescale (compress to a size more appropriate for a standard monitor) the images, please post them as links.

[Mike82]

Sorry about that was not sure how to post pictures or how to fix how big they popped up as.

[jyqureshi]

Mike: I'm using flick-r, which automatically gives you different sized pictures once you upload them.

[Mike82]

I just have a quick question to ask you guys about the X-Over. I am having a guy named Skip the technical support advisor at Parts Express do it for me. He said he would go through it and check everything and make upgrades to the quality of the parts as he thought would matter in certain areas. He does all this and test them for 40 dollars at the most he said it would be. I thought that could not hurt as long as he did not go crazy with the price. He called today and said he went through and changed a few parts to more quality parts and said the total was only 104 dollars. How is that possible though considering the original X-Over design costs around a 140 dollars. I am thinking I should maybe pull out of the deal. What do you guys think?

[Jim Holtz]

I just have a quick question to ask you guys about the X-Over. I am having a guy named Skip the technical support advisor at Parts Express do it for me. He said he would go through it and check everything and make upgrades to the quality of the parts as he thought would matter in certain areas. He does all this and test them for 40 dollars at the most he said it would be. I thought that could not hurt as long as he did not go crazy with the price. He called today and said he went through and changed a few parts to more quality parts and said the total was only 104 dollars. How is that possible though considering the original X-Over design costs around a 140 dollars. I am thinking I should maybe pull out of the deal. What do you guys think?

Hi Mike,

It's not hard to spend more money on crossover parts. The parts spec'ed are the the "bang for the buck" parts rather than the the best you can get at any price. The performance will be excellent with the parts in the BOM. More expensive parts can theoretically make it sound better. That's up to you to decide.

Jim

[Mike82]

Spending more money is understandable but spending less money is what I dont get. The original cost around 140 for both he quoted me 104 for both. Thats after he said he was going to upgrade a few things. I am confused and really wish i told him to stick to the original. Oh well hopefully it turns out alright. I ended up getting some 2in OC 703 insulation and some of Parts Express Sonic Barrier 1" Acoustic Foam. I figured why cheap out on the cheap stuff when I am already this far in. I will post more pictures when I get time. Oh by the way i was going to ask you where did you mount the X-Over board in the mini's?

[Curt C]

Well, I don’t know Skip, but as the crossover designer, I question how he determined some parts ‘needed’ upgrading in the first place, and how he could tell the upgraded parts would be beneficial without listening tests. He may be on the up and up, but to be on the safe side, I’d want to see a list of the substituted parts and what he chose as an upgrade if it were me.

If you need any assistance with this, send me a PM. Perhaps I can help.

C

[---k---]

You sure it isn't $140 + $104 = $244??? I could see that.

[Jim Holtz]

You sure it isn't $140 + $104 = $244??? I could see that.

I agree with you Ryan. My guess is he replaced the one electrolytic with a poly cap and added Mills resistors.

Jim

[johnathanwinter]

since the guy works at parts express he may be only paying cost for the parts and not retail like we are so the price could be much lower.

[Mike82]

I agree with you Ryan. My guess is he replaced the one electrolytic with a poly cap and added Mills resistors.

Jim

Do you think if he replaced those parts it would make it not sound as good as the original. Or I am guessing it is hard to say.

[Jim Holtz]

Do you think if he replaced those parts it would make it not sound as good as the original. Or I am guessing it is hard to say.

I think they would sound at least as good with Mills resistors and poly caps. Honestly, that is what I normally spec. However, with those parts the cost came uncomfortably close to the cost to Build Statements, so after discussing options with Curt, we decided that the speced parts could be used with out impact to the sound quality of the Mini's.

Go with what ever fits your budget and they'll sound great. :T

Jim

[Mike82]

I got ahold of Skip today and found out the only thing he changed was one of the inductors he replaced the 4.7 mH 18 gauge Dayton with a Jantzen is all. The price was quoted at 104 dollars but he forgot a few parts so now it is back up to 150.

[Jim Holtz]

I got ahold of Skip today and found out the only thing he changed was one of the inductors he replaced the 4.7 mH 18 gauge Dayton with a Jantzen is all. The price was quoted at 104 dollars but he forgot a few parts so now it is back up to 150.

Actually, inductors are the one component I wouldn't change unless you can match the DCR. A change in DCR of the inductor will impact the crossover. If it's minor, it's not a big deal.

Jim

[Mike82]

Was going to put the insulation in the cabinets toady and was going to ask. What the best way for installing it? I was thinking about using spray adhesive and sticking it right to the wall. But I am wondering if I should cover the insulation at all with fabric?

[Jim Holtz]

Was going to put the insulation in the cabinets toady and was going to ask. What the best way for installing it? I was thinking about using spray adhesive and sticking it right to the wall. But I am wondering if I should cover the insulation at all with fabric?

I use 3M #77 and I never cover the insulation.

Jim

[Mike82]

I got the insulation installed today and the foam cut. I read through the minis thread and found that I should hold the 1in foam 2in back from the front baffle and then cut a 45 degree angle. Is this still what is considered the best? I have everything I need to finish except the X-Over still waiting waiting on Skip :x. I was planning on mounting the X-Over on top of the mid tunnel, you think that is a good place for it? I will post more pictures of my progress Monday if I get time.

[Jim Holtz]

I got the insulation installed today and the foam cut. I read through the minis thread and found that I should hold the 1in foam 2in back from the front baffle and then cut a 45 degree angle. Is this still what is considered the best? I have everything I need to finish except the X-Over still waiting waiting on Skip :x. I was planning on mounting the X-Over on top of the mid tunnel, you think that is a good place for it? I will post more pictures of my progress Monday if I get time.

Hi Mike82,

Yes, the 45 degree angle on the 1" mid foam and 2" back from the front baffle is what I'd recommend to start. I would not glue the mid foam in place until you're completely done, however. You can "tune" the mids depending on the reflectivity of your room by sliding the foam closer/further away from the back of the mid driver.

Also, holding the foam/insulation back from the front baffle 2" should also be followed in the woofer compartments.

I would not recommend mounting the crossover on top of the mid tunnel. The closer to the binding posts and the ability to remove the crossover after completion is important. At least the part about being able to get it out through a woofer hole after the speaker is built. "Opps!" happen and that allows you to fix the crossover if necessary.

HTH

Jim

[Mike82]

Here are a couple of pictures of the insulation, seems like it takes up too much room. I held it back from the front baffle 1 1/2in. I have to trim the piece under the mid tunnel so that the top woofer dont hit it. Do you guys think it would hurt to put some in on the top I have some left over I could throw up there.

[Jim Holtz]

Here are a couple of pictures of the insulation, seems like it takes up too much room. I held it back from the front baffle 1 1/2in. I have to trim the piece under the mid tunnel so that the top woofer dont hit it. Do you guys think it would hurt to put some in on the top I have some left over I could throw up there.

I think I'd recommend beveling the fiberglass at a 45 degree angle too. If it crowds the RS225's they'll have a dead sound. No rocket science, just lay it back for a smooth transition.

Jim

[soundtrek]

Fiberglass insulation

Mike, where did you get the fiberglass insulation you used in your cabs? I am planning a Mini Statement build as well. Thanks Kevin.

[Mike82]

I got it at atsacoustics.com

http://www.atsacoustics.com/cat--Fiberglass-and-Mineral-Wool-Batts-and-Boards--106.html

[Mike82]

Does anyone know what kind of equipment I would need to check the DCR of a X-Over. The only reason I ask is the guy I got doing my X-Over makes me concerned it is not right considering he changed the 4.7 mH 18 gauge Dayton Inductor and has come up with every excuse in the book why it is not done yet.

[Curt C]

Does anyone know what kind of equipment I would need to check the DCR of a X-Over. The only reason I ask is the guy I got doing my X-Over makes me concerned it is not right considering he changed the 4.7 mH 18 gauge Dayton Inductor and has come up with every excuse in the book why it is not done yet.

Only the inductors have DCR, and they will be difficult to measure accurately without a milliohm meter. If he is substituting the Jantzen P-core 255-116 for the PE laminated 266-566 that will be fine. The difference in DCR is .17 ohms, and will make little, if any difference in the woofer response.

C

[Mike82]

I finally got the X-Overs today only took him about a month too do lol. After doing a little research about how to lay a X-Over out and how not to get the inductors too close to each other makes me wonder if this was done right. Please take a look and let me know what you think.





Here is that site I got the inductor placement from

http://www.troelsgravesen.dk/coils.htm

[ThomasW]

Air core are more forgiving of close proximity than iron core, but those are too crammed together ..... IMO

[savage25xtreme]

technically speaking, I don't see any of the cores lined up on the same axis unless some are too close... what happened to the iron core inductors? replaced with air cores? I'm certainly no expert though. Looks like it was a royal pain to get it packed that tight though :B

Edit: I would listen to Thomas 8)

[Mike82]

How do i know for sure if the placement of the inductors is compromising accuracy is there any way to test it. Curt said I could test the DCR of the inductors with a milliohm meter but can you test the whole board anyway. I am pretty frustrated at this point I payed 55 dollars for this guy to do this right and in a timely fashion considering I dont know how. What I got was bad work which took him a month to complete after lying to me over and over again about it will be done the next day or it will be shipped the next day :M . And after all that getting jerked around it is done sloppy. He still wont tell me what he used to replace the 4.7 mH 18 gauge Dayton inductor with. All I can say is this guy is lucky he lives 500 miles from me.

[Jim Holtz]

Inductor Chart..

Here's the inductor chart I go by. Get your ruler out and do a little measuring. If you're close, it'll be OK.

Reposition the ones that could be an issue and you'll be good to go. It looks like the extra money your builder suggested you spend bought Jantzen air cores to replace the Dayton steel core inductors. Curt can comment on the effect of the different DCR.

Jim

[Curt C]

Whoops!
Disregard parts of my PM regarding this crossover, as I forgot I spec'd a cored inductor for the woofers. ops:

From looking at the pics, I'd guess a 2.7 mH and a 2.0 mH was substituted to make up the 4.7 mH, and it looks like 18gauge inductors were used. The DCR will be significantly higher, and in this instance is an unnacceptable substitution, regardless of the less than optimal component layout.

I sent you a PM with resolution suggestions.

C

How do i know for sure if the placement of the inductors is compromising accuracy is there any way to test it. Curt said I could test the DCR of the inductors with a milliohm meter but can you test the whole board anyway. I am pretty frustrated at this point I payed 55 dollars for this guy to do this right and in a timely fashion considering I dont know how. What I got was bad work which took him a month to complete after lying to me over and over again about it will be done the next day or it will be shipped the next day :M . And after all that getting jerked around it is done sloppy. He still wont tell me what he used to replace the 4.7 mH 18 gauge Dayton inductor with. All I can say is this guy is lucky he lives 500 miles from me.

[john trials]

Not seeing Curt's PM recommendations, I'd add that you should position the resistors with a little space in between, so they can dissipate some heat. Not a lot of space, but not stacked on top of each other as they currently are.