New Project

[ThomasW]

Crossover design:

[catacon]

Yeah, that block diagram was the one I was following. I think the crossover is working. I tried much higher frequencies (10,000;5,000;500;40) and it seems like it's working.

The parts for my MTM crossovers are coming today, so I'm sure I will have more questions.

[catacon]

Well I got the MT's done and they sound good. They are fairly quiet (or at least quieter than my former speakers). I usually play music at -45 to -40 dB, now I am at -35 to -30. Is that typical of these speakers?

The parts for my MTM's arrived, so I will get started on those shortly.

Thanks again for all the help guys!

[ThomasW]

Well I got the MT's done and they sound good. They are fairly quite (or at least quieter than my former speakers). I usually play music at -45 to -40 dB, now I am at -35 to -30. Is that typical of these speakers?

I'm not sure what "quiet" means. The speakers are probably less efficient when compared to your old ones.

[catacon]

By quiet I mean that with my old speakers I was at a comfortable listening level at -45 dB preamp on the receiver. Now to get to that same listening level with the new speakers, I have to turn the receiver up to -35 dB.

Does that make sense? Maybe I'm just being paranoid since these are my first crossovers/speakers and I don't really know what to expect.

[ThomasW]

As I said the new ones are less efficient.

[catacon]

All right, all the crossovers are done, and they appear to be working. The MT's are completely done and they sound really good. I have a little more work to do on the MTM cabinets, and then I will be finished.

Thanks for all the help!

[catacon]

I just finished the MTM's about an hour ago and they sound great. They have very clear highs and nice lows too (even though the subwoofer covers most low frequencies). Now I just have to build the WMTW center and I will have built a complete 5.1 surround system!

I assume I will need to add some damping material of some sort. I was looking at the 1" Sonic Barrier stuff from PartsExpress. Will that be sufficient for both the MT's and MTM's? Is there something else I should look at?

Thanks for all your help guys! Thanks for putting up with my stupid, beginner questions and not getting annoyed with me (or at least not saying you were annoyed). Thanks to the people who designed the speakers and everyone who helped answer my questions! Your guys rock!

-Aaron

[---k---]

I just got in a bunch of the 1" Sonic Barrier for my 3-ways. I think it will work out well for you. There are more expensive options, that others will recommend. I've read that Jon likes to use Wispermat. There are also less expensive options such as egg crate foam and carpet padding (use with caution). I think the Sonic Barrier is a good happy medium, especially if it is in your budget.

[Dennis H]

The PE Sonic Barrier looks like about the same stuff as Whispermat. I'd get whichever one is cheaper. Of course, OC703 is probably cheaper yet.

[catacon]

I heard that egg crate foam is worthless and that carpet padding is hit or miss. Doesn't Whispermat only come in really big sheets, so it is only worth getting if you make a lot of speakers?

I had one more question: How far from the wall should the MTM's be? Right now I have them about 1-2" away.

Thanks!

[JonMarsh]

To optimize the performance of any monopole speaker, (that is, as smooth and flat as possible), the woofers should be at golden mean ratio's from adjacent boundaries. The guidlines on the Cardas web site are a good starting point. Placing them closer to a wall will tend to elevate some of the midbass, and if you have two boundary distances the same, you'll get a bigger hump and a suckout else where. Room setup is unfortunately often overlooked. For HT with a 80 Hz or higher crossover from the sub, the setup is less critical.

This thread discusses these points in more detail.

[ahaik]

I use fiberglass insulation from home depot, works great for me, as far as I understand it absorbs low frequencies better and is very cheap, only problem is that its itchy (I use long clothing a mask, goggles and gloves).
I buy the one that say's acoustical (or something similar to that) without the paper backing.

[ThomasW]

I assume I will need to add some damping material of some sort. I was looking at the 1" Sonic Barrier stuff from PartsExpress. Will that be sufficient for both the MT's and MTM's? Is there something else I should look at?

The foam is a quick and easy solution for either the MT or MTM. The foam is more expensive and not necessrily better than fiberglass. The foam is of course much more user friendly to install...

As Jon indicated the speakers are designed to be 1'-2' away from the wall. If yours need to be 1"-2" from the wall you should have built the in-wall/on-wall crossover version of the design

[catacon]

Does the fiberglass need to be attached in any way?

I'm confused about the placement. Does the rear wall mean the wall behind the speaker? I have the MT's about 1-2' away from the wall, however the MTM's are 1-2" away and I didn't know there was an on-wall version of the MTM.

Thanks! Sorry about the noobish questions.

[ThomasW]

The 'glass' should be attached to any blank/open surface inside the cabinet.

No one used the term "rear-wall"

The pair you built are designed to operate 1'-2' away from any wall/boundry

[catacon]

What is the best thing to attach fiberglass with?

The term "rear-wall" came up in the link Jon posted. It talked about placing the speakers so far from the rear wall, side wall and the floor.

[ThomasW]

Hot glue, spray adhesive, staples, take your choice

[catacon]

Great, thanks!

[ahaik]

I use spray adhesive and staple next to the drivers in order to keep the fiberglass away from the drivers.

[catacon]

The final thing to do to these speakers (after damping) is to veneer them. I was looking at Pmazz's guide, it looks like a simple, straightforward way of veneering, so I think I will use that method. I plan on buying veneer from ebay, unless someone can reccomend where to get low priced veneer. Does anyone have experience buying veneer from ebay? If so, did it work out well? Also, does it matter whether I get paper-backed or no-backing veneer? I assume paper-backed will be easier to work with.

Thanks!

[catacon]

Anybody?

[Dennis H]

Paper backed is easier to use. No experience with ebay. Tapeease is good and reasonably priced.

http://www.tapeease.com

[Brian Bunge]

I'll second Tape Ease. I order all of my veneer from them. In roughly 5 years only once have I gotten veneer that had any kind of damage to it and even then they promptly replaced it. I have no reason to look elsewhere.

[catacon]

TapeEase looks nice. I like that they sell 4x8' sheets. I was having trouble finding sheets wider than 15".

[here.now]

Not to hi-jack the thread but I wanted to ask a quick question regarding the less expensive BOM. I've built one Modula MTM to spec, followed the BSC XO and all of the materials that were in the original build thread. After building one and then looking at my checkbook to see how much I had actually spent, I(*cough* WAF) decided not to build it's brother. So I'm currently using it as a center( I know shame shame).

My question is, would it be a bad idea to build a buget Modula and pair it with the non-budget? I'm afraid I'll end up with two different sounding speakers.

My other option would be to disassemble and build the statements or essential use these parts to build two identical speakers.

I'd love to have a matched 5.0 set and was considering building the second Modula and center/modula mt's but my pockets aren't deep enough at the moment.


Any ideas?

[ThomasW]

The NatP is a budget version of the Modula MTM. They should work fine as mains.

[here.now]

I guess I was asking whether or not I could pair a budget modula with a non-budget. I just don't want to have two different sounding speakers. Also is there a new thread for the WTMW center?

Thanks

-Jeff

[Dennis H]

I guess I was asking whether or not I could pair a budget modula with a non-budget.

No. The L&R need to be the same. The center could be different, within reason.