First Build OS MTM + CC

[oTRONo]

Building my first project. Overnight Sensations MTM's for the mains, Center Channel, and TM's for surrounds. Just finished the mains and I am impressed. They sound MUCH better than the Polk TL150's I was using. MTM's were modified to be wall mounted and so will the TM's surrounds when I build those at a later date. TV is a 47". Center Channel is waiting for the backordered B3N's to arrive.

Wanted to keep it cheap so the cabinets are not any where near the quality you guys do, some of which I find amazing. It's 1/2" Lowe's 4-ply plywood. Stained with American Walnut and about 5 coats of poly. Turned out OK I guess. I figured if I wanted to build new cabinets with better wood later, I'd only be out about $12 worth of wood on these cabinets.

Sub I'm using is an Infinity Reference 1062w 10" with a Mirage Omni S8 100w rms amp I had extra from a previous sub. Enclosure for that will probably just be painted black.

[oTRONo]

Re: First Build OS MTM + CC

Used a French Cleat method for mounting. The unstained piece mounts to the wall and speaker just barely fits on at an angle then drops down. Can't fall off the wall if push straight up. Didn't want the kids knocking the speakers off.

[isaeagle4031]

Re: First Build OS MTM + CC

Nice work! Those cabinets look darn good. And the xovers do too. First time or not, you did a fine job on them. Congrats!

[oTRONo]

Re: First Build OS MTM + CC

Nice work! Those cabinets look darn good. And the xovers do too. First time or not, you did a fine job on them. Congrats!

Thank you very much. I still have to make a grill for them so my kids don't poke their finger through the tweeter or something. I have 2 handicapped children and they don't understand they can't touch them.

Debating whether to redesign the center channel xover. As it is now, once I seal the cabinet up, there is no way of getting it out. The holes for the B3N's are just too small. Xover's for the mains are small enough to be removed though.

[isaeagle4031]

Re: First Build OS MTM + CC

Maybe make 2 separate xover boards. 1 for the mids, 1 for the tweets. I've had to do this a few times for the same reasons.

[oTRONo]

Re: First Build OS MTM + CC

Maybe make 2 separate xover boards. 1 for the mids, 1 for the tweets. I've had to do this a few times for the same reasons.

Yeah, I am just about to do that, but I'll probably make 3 seperate boards, for tweets, mids, and bass. It's a 2.5 design. The bass woofers only have an additional inductor, but they are big.

[the kid]

Re: First Build OS MTM + CC

Maybe you could assemble the xo as intended, and then place it behind your stereo equipment. This would incur running several wires to the speaker rather than 1, but you now have just 1 xo to make and it is readily available were someting needed changing on it. If you move or sell in the future, then use the split xo method if necessary.

[oTRONo]

Re: First Build OS MTM + CC

Center Channel xover redone. Now just waiting on the drivers to arrive (still backordered )

[oTRONo]

Re: First Build OS MTM + CC

Speakers are done with the exception of the B3N's still back ordered till the 25th

Now I wish I hadn't gone cheap on the wood. I had some splintering when drilling the holes for the grill guides. Nothing I couldn't fix, but I see where better wood can be easier to work with.

Not sure if I'm going to build the TM surrounds or wait and "upgrade" to a better speaker when I can. If I upgrade, I'll build a full 5.1 or 7.1 set then and move these to the bedroom. I love how these sound, but I can see the limitations of a 4" driver. I've been eyeing some builds using the Dayton DA175 7" driver. I'll have to save up a bit for those though.

[kanemack]

Re: First Build OS MTM + CC

nice job! don't worry too much about power limits. OS MTMs scream with very little power.

[oTRONo]

Re: First Build OS MTM + CC

nice job! don't worry too much about power limits. OS MTMs scream with very little power.

Thank you.

I have no worries about the power limits. I'm just thinking I'd like more "impact" and the 4" drivers just aren't enough for a home theater. Don't get me wrong, they sound great. I'm just looking for more, for instance, the attack of a bass drum. It just feels lacking. I may be thinking wrong and should be looking at the subwoofer I have and not the OS's.

I have a 10" Infinity Reference 1062w. Custom 0.75 ft^3 sealed enclosure with an amp I have from a Mirage Omni S8 subwoofer. Could it be the subwoofer I need to improve and the OS's are just fine? I am planing on eventually upgrading the amp as I wouldn't doubt that amp has some circuits in it specifically designed for the mirage subwoofer. I know it at least has a bass boost around 35hz from what I can hear. Plus, it's 100w rms and the Infinity is rated up to 275w rms. Could I be underpowering it enough to not get the impact I want? It definitely shakes the room especially at low frequencies but doesn't "hit" very hard at all.

Maybe I'm just expecting too much from smaller speakers. I've never had the opportunity to listen to some high end home theater speakers so I'm not sure what to expect.

[Paul Carmody]

Re: First Build OS MTM + CC

I think if you want to dig deep, you'll need a vented or PR sub. Nothing against sealed subs; they are the preferred sub for many around here. Plus, they have the added benefit of being easy to design. However, getting low, pounding, growling bass is out of a sealed sub is like trying to get an emu to fly. It's just not what they're for. Sealed subs have a very gentle roll-off, that can often start quite high in frequency (compared to vented/PR subs, that is). Many sealed sub users will play around with positioning the sub in the room to maximize room modes and cabin gain--essentially counteracting the gently tapering Frequency Response.

[oTRONo]

Re: First Build OS MTM + CC

Thanks for the reply Paul. So I should be looking at improving my subwoofer rather than going with larger mains? I do like the OS's and if I do build new mains, these will go into the bedroom as my wife enjoys watching movies in bed rather than on the couch.

I knew going into building the sub that the amp wasn't ideal, but I already had it and figured I'd try it. I get plenty of low end, but it's more "rumble" than it is "chest pounding" and it is loud. I originally built the enclosure as a 1.75 ft^3 vented, tuned to about 25hz. The low end was just over powering everything else due to the bass boost of the amp, which I didn't know it had. That's why I went sealed, modeled in WinISD. I still wonder what kind of filters it has on it as it was designed for a specific driver in the S8.

When I get a new amp for it, I will either go back to the original enclosure or build a new sub based on a proven design. Should I still use the Infinity 10" or should I get a new driver along with the amp?

[oTRONo]

Re: First Build OS MTM + CC

Update. It seems the subwoofer was out of phase. Switched it and it seems to fill in more. I messed with that before and it didn't seem to make much difference, guess I just wasn't listening to the right material at the time. I really can't wait till the center channel drivers arrive. Should be a little over a week according to PE.

Thank you Paul for the fabulous design. I was looking for subwoofer designs when I discovered these, didn't know there were full range designs out there, especially at this budget. I'd still be using the crappy Polk TL150's I bought on clearance at Best Buy. The more I listen to these, the more I like them. I do have some port chuffing at low frequencies due to the 1" x 4" ports. I'll probably change them out for the 1 3/8" ports but those would require a bend. I'll mess with that later, the chuffing isn't heard very often.

Still think a new amp and enclosure for the sub would help. Is there anyone using an Infinity 1062w out there? I found the Digger 8 build which uses the 8" version, but nothing using the 10".

[oTRONo]

Re: First Build OS MTM + CC

Update. Just replaced the amp with a Dayton SPA250. WHAT A DIFFERENCE. The Dayton amp is twice as heavy, must be better right? I now get the "thump" I was missing. Also seems to be a flatter response across the spectrum instead of the peak around 35hz. I have to keep the gain on the new amp at about 1/4 instead of 3/4 on the old amp.

Much better integration with the OS's now. I'm happy. Now debating whether to rebuild the ported enclosure or keep this one.