New to DYI, MTM Dayton RS

[nox9colt45]

Hey, first time poster here, been in avsforum for a few years now. Just starting to get into DYI and sounds really really fun. Sorry ahead of time if this seems stupid to you all. Goal is not to make myself look like an idiot

Here it goes:

Lookin to build MTM setup (almost just like Dr. K's MTM on partsexpress) with 2X DAYTON RS150S and a tweeter (was gunna go soft dome because i got that now in fluance, like the highs, and the rs dayton is 4ohm, which my receiver cant handle) I have found many setups very close to this, but nothing exact for crossover settings. Questions are...

1) Creating crossovers confuses the SH** out of me. Ive tried for a while now to understand, get bits and pieces, but its hard. Is it much worse just buying a premade crossover?

2) Silk dome vs Aluminum. I understand this will be hard to explain, audio is all preference. I like the sound of my silk domes on my fluance now. I would assume the titanium would give a bit more sharp/harsh sound, while soft dome a bit more... well soft.

3) Port vs Sealed. I have built many sub boxes, and for subs, i always go ported. But when it comes to my Arrays, i would like to have all 5 speakers the exact same build, and for rears i would at least like to be wall mounted if possible. Also, sealed give higher quality sound... just less loud (correct me if im wrong). Is it generally a 5db drop when playing around 80db? or how would they compare? Lookin to build .75-1 ft3 box. Havn't set anything in stone, still trying to figure out the whole DYI deal.

Thanks bunch guys, limme know if any other info is needed.

[WillyD]

I am by no means an expert, but I will do my best to answer your questions.

1) With the knowledge available here, you don't have to worry about crossovers much. There are already many established designs that are exceptional. The designers have done the hard part for you by designing the crossover, testing it, and providing a diagram of it.

2) As you said, it is all about preference. If you like soft dome tweeters then by all means, use them in your build. I prefer soft dome as well, and just built the Modula MTs and I have been very happy with them. Thats the great thing about DIY, you can build exactly what you want. Also, a good hard-dome should not be "harsh" or "bright"...at least that is what I have come to believe. The Dayton Reference tweeter is supposedly pretty neutral sounding, for instance.

3) Assuming you will/already have a sub, going sealed is perfectly fine. Hell, you could still go sealed without a sub, but you would missing out on a lot of mid/mid-low bass.

It sounds like to me that the Modula MTM is pretty much what you are looking at building. If I were you, I would take a look at it and consider it. You could then build the Modula MTs for surround duty. Just a thought... :T

[kejolly]

nox9colt45,

you might want to check Chris's (cjd) MTM out here

http://www.eldamar.net/audio/RS150MTM/

He has been helping me with my RS150 MTs. I am very much like you in that XOs escape me for the time being. I am sure if you private message him, he will be more then happy to answer any questions you have on his design.

Kevin

[Brian Bunge]

Chris' design was the first thing that came to mind, although there's one flaw in your logic about not using the RS tweeter because of it being 4 ohm. When you add the two RS150's in parallel, which is what you're going to do with Chris' design, you will affectively have a 4 ohm load. So which tweeter you use would not matter at that point.

Having said that, unless you just really have a very cheap receiver, I think you could probably handle the 4 ohm load. And, I know from experience that the Seas silk dome tweeter is very nice. You'd be hard pressed to find a better tweeter at any price.

[kejolly]

If you look at the 1800hz XO, Chris has it designed to be used with the Seas 27TDFC tweeter. It is a soft dome that is widely used by many and isn't bad on price.

Kevin

[cjd]

There is also a version there eith the RS28A @1800 farther down the page.

Oneof these days I really am going to rework that page. Make it easier to read.

FWIW, the 2100Hz version with the 27TDFC won the budget class at the 2005 Chicago DIY get-together.

C

[nox9colt45]

I was really liking the 2100 XO design.

About the 4 ohm load, i have an Onkyo TX-SR502, and manual says, and i quote, "Only use speakers with an impedance of 6 ohms or higher. Connecting speakers with an impedance of less than 6 ohm may damage the AV Receiver" I could be wrong? impedance = ohm of speaker? i hope not :P .

How much less clear is 4ohm? I got my car sub (alpine type-r) running 4 ohm, and it sounds good. I am also planning on running my sub at 8ohm, that i will be making. Havnt heard midrange/high's in 4 ohm though. Lastly, my receiver puts out 75w @ 8ohm, and i cant find how much it would put out @4 ohm, this is if it can handle it of course.

About the sealed, i will have a sub. I am building sub and l/c/f all within a very simular time frame. Still got lots of research to do before i start the projects.


Thanks a lot guys, this is helping a lot.

[cjd]

I run mine with an amp that isn't terribly stable at 4ohm and ported, I run out of excursion before the amp has issues. Impedance low is actually closer to 5ohm with the Seas tweeter. Impedance is measured in ohms...

If you plan to do one as a CC I highly recommend the 1800 XO version.

If you use the Seas, a small box around the tweet is a good idea. Difinitely with the shielded version. The aluminum RS tweeter face should be fine without, though I like the addad security ...

C

[nox9colt45]

Anyone 100% sure if my TX-SR502 will be able to handle 4ohm? I'm on a budget, and if i blow my receiver, i am pretty much F***ed :M


Just took a look at parts express, and i see that the non-shielded version of the rs150 is 4 ohm, so i could parallel to 8? I have an LCD TV, those are fine without shielded correct? Lastly, would crossover parts need to change a long with the speaker?

[cjd]

Anyone 100% sure if my TX-SR502 will be able to handle 4ohm? I'm on a budget, and if i blow my receiver, i am pretty much F***ed :M


Just took a look at parts express, and i see that the non-shielded version of the rs150 is 4 ohm, so i could parallel to 8? I have an LCD TV, those are fine without shielded correct? Lastly, would crossover parts need to change a long with the speaker?

Not sure on the receiver.

You would be looking at a totally different design goung with the 4ohm RS150's.

C

[Brian Bunge]

I would think that your receiver would go into protect mode before it ever got hot enough to cause any kind of damage, but that really depends on how it was designed.

And, just for the record, if you used dual 4 ohm drivers then you would have to wire them in series to get an 8 ohm load. Not in parallel. That would give you a 2 ohm load.