[Vapor Audio]

Thanks Danny, they did turn out nice.  I'm getting pretty decent at putting down veneer by now.  That bubinga was really hard to work with too.  Lots of open grain, and really brittle.  They probably weigh twice as much as they did when I started, and feel totally dead.  Overall the boxes were a success, although probably more of a PITA than doing some from scratch. 

Yea Ryno, they're active between the top and bottom - with the standard A/V3 crossover for the top.  But I think I've mentioned that a couple times already in this thread

They're done now btw, hooked up and I've been cranking em for the last 3 hours.  All I can say is they're the best speakers I've ever heard in my house.  I feel like going nuts with adjectives, but they've only been up for 3 hours Seriously though, wow!  They sound absolutely huge, notes and vocals mixed stereo just float in about a 8'x4' elipse in the middle of the stage, and individual instruments can be pinpointed perfectly when the recording means it that way.  What I had hooked up immediately before was the Nat P - MTM using Dayton RS180/RS28a.  Honestly, I enjoy those a lot, and didn't expect these paper drivers to match the detail from the aluminum Daytons, but they really do ... and exceed it noticably. 

I think this is what I was looking for all along!  Loads of detail, I'm already hearing things I haven't heard before - like decay on acoustic guitar notes.  But the trick for me was I wanted that detail, but still be able to crank poorly recorded metal and not have my ears melt like many 'detailed' speakers will do.  These had no problem playing Pantera - Walk at volumes I've never attempted before   And did somebody say dynamics!!!

Expect a full report tomorrow, I'm stoked though.  I'm really anxious to let some of the Zaph nutlickers who quantify a driver only by it's distortion measurements take a listen to these though 

[Danny Richie]

What I had hooked up immediately before was the Nat P - MTM using Dayton RS180/RS28a.

Be sure to pass on your impressions to the knuckleheads over at HT Guide.    They think those metal cone drivers are "it", and educating them is as fruitful as beating my head against the wall. When I first heard the Nat P design it was so veiled I thought there might be something wrong with it. It turns out that all of those RS series drivers sound like that.

I'm really anxious to let some of the Zaph nutlickers who quantify a driver only by it's distortion measurements take a listen to these though

I have been working on a response to that malarkey. I might have something finished up to where I can post it before the weekend is over. I didn't realize just how far off base some of that crap was until I really started reading through it.

Thanks a lot Turbo for sharing your build process. It looks like you have made a great speaker.

My only concern is if it is tall enough for you. That design (MTM) needs to have the tweeter up at ear level. A short stand made from a dark colored (maybe Black) block of wood might do the trick and match nicely with it. It'd be a nice contrast to the Black drivers.

[ryno]

This MTMWW in an all passive design would be a direct competition with the dayton MTWW thats pretty hot on the HT forum.
Ryan

[Danny Richie]

Personally I really don't see anything using the Dayton drivers as much competition for anything unless the comparisons exclude listening to them.

[Vapor Audio]

Be sure to pass on your impressions to the knuckleheads over at HT Guide.    They think those metal cone drivers are "it", and educating them is as fruitful as beating my head against the wall. When I first heard the Nat P design it was so veiled I thought there might be something wrong with it. It turns out that all of those RS series drivers sound like that.

My Nat P sounds decent actually, better than my Wharfedale Evo 30's, Paradigm Studio 40 v2's, and Ascend 340-SE's ... but these new towers really blow them away.  And I know these are only going to get better, since the M-130's aren't even close to broken in yet

I think it's time to sell some speakers!

I have been working on a response to that malarkey. I might have something finished up to where I can post it before the weekend is over. I didn't realize just how far off base some of that crap was until I really started reading through it.

Thanks a lot Turbo for sharing your build process. It looks like you have made a great speaker.

My only concern is if it is tall enough for you. That design (MTM) needs to have the tweeter up at ear level. A short stand made from a dark colored (maybe Black) block of wood might do the trick and match nicely with it. It'd be a nice contrast to the Black drivers.

I saw your response, it looks good and it was right of you to address those issues!  I could have easily turned into one of those Zaph nutlickers, but you convinced me to listen to you instead.  I'm glad I did, or I certainly wouldn't have these speakers here today!  And honestly, that 2.5 way almost pushed me over the edge - no fault of yours though, it was one bad tweeter and poor modeling in PCD that made them turn out so mediocre.

Fortunately my couch is an old POS, and my butt sinks way down in it ... so the tweet is pretty much exactly at ear level.  I did make the wood base and put those spikes on the bottom to get them up to ear level though.

I'll start a new thread about results soon.

[Danny Richie]

Fortunately my couch is an old POS, and my butt sinks way down in it ... so the tweet is pretty much exactly at ear level.  I did make the wood base and put those spikes on the bottom to get them up to ear level though.

Perfect! 

The base certainly looks great too.

[ssabin]

Danny,

Taking this concept to the more extreme, what results would you expect from a similar design, but replacing the G2 tweeter with a Neo 8 or Neo 3 and doing a 3-way active crossover? The upper box would have to be re-designed a bit, I would imagine, but this is very intriguing to me.  Maybe TMMWW or even TMWW (using M-130 8-ohm version) would be preferrable?

[Danny Richie]

How about we really take it up another notch and we put the MTM upper section in an open baffle?

http://www.gr-research.com/kits/ob-5.shtm

Yes, it is really, really good.

We can take it up another notch with this one:

http://www.gr-research.com/kits/ob-7.shtm

[ssabin]

I had not looked at the OB kits before.  They are intriguing, although I'm a bit fearful of the extra height even the OB5's have over the AV3.  The cabinets look like they might be a bit tougher than the AV3's too, which is important since my ultimate goal would be to build 7 of these things.

Is the OB5 more tolerant of placement (proximity to walls) than the AV3?

Thanks, Danny.

p.s.  Even these newer designs don't utilize the M165x driver.  Do you have anything in the works with the M165X?

[Danny Richie]

They are intriguing, although I'm a bit fearful of the extra height even the OB5's have over the AV3.

I set the tweeter height at 40" on those. You can make them shorter though if you like.

Rocket Ronny built his shorter and added depth to the box to get back his air space for the lower woofers.

http://www.audiocircle.com/index.php?topic=31630.30

Is the OB5 more tolerant of placement (proximity to walls) than the AV3?

Through the upper ranges (200Hz and up) it is less sensitive to room placement regarding side walls. It could be more sensitive to the rear wall distance as you wouldn't want an open baffle design right up against a wall. In the lower ranges (below 200Hz) it is just like any other speaker.

Do you have anything in the works with the M165X?

Raw Acoustics is releasing kit with a single M-165X and their ribbon tweeter.

[ssabin]

Boy, I read through that thread, and the OB5s sure get a lot of love.  That's even more intrgiguing!

Rocket Ronny lowered the bass box and made it deeper.  Since this portion of the speaker only drives the lowest frequencies, can the baffle width of the bass unit change instead of the depth?


The center channel version got me thinking though.  Would the MTM portion stay open baffle?  It would be a horizontal open baffle sitting on top of the bass bin, if I'm getting that correct.  Which then inspires other thoughts - move the port of the bass unit to the front, or seal it completely, to allow the center to go much closer to the wall. 

And that led to another thought - would using the M165-X in the bass section allow for better LF extension?  F3 at 45 Hz is no slouch, but for some 5.1 material, getting a bit lower on at least the FL and FR speakers is advantageous.  If so, would it do so with the same quality as the M130-16?  What would the volume of the of the bass unit become to optimize those larger woofers?  Or would the woofer-mid crossover no longer work?

And I like the completely open top of these - at least half the speaker just became very easy to build!

Thanks for your quick feedback, Danny.  I wasn't planning on starting working on speakers any time soon, but now I'm getting itchy.  Just have to get two other "small" projects around the house done first.  Or do I?.....

[Danny Richie]

Since this portion of the speaker only drives the lowest frequencies, can the baffle width of the bass unit change instead of the depth?

So long as you are not adding baffle width (reflective surface area) you can re-shape the air space to your discretion. 

The center channel version got me thinking though.  Would the MTM portion stay open baffle?

Sure. Then just move a single M-130/16 to each end. It can be sealed or ported. You could even build ports into the stands.

would using the M165-X in the bass section allow for better LF extension? F3 at 45 Hz is no slouch, but for some 5.1 material, getting a bit lower on at least the FL and FR speakers is advantageous.  If so, would it do so with the same quality as the M130-16?  What would the volume of the of the bass unit become to optimize those larger woofers?  Or would the woofer-mid crossover no longer work?

Yes, but those are 8 ohm woofers, so a pair of them will drop you into the 4 ohm load range. The box size for them is much larger too. Ported, each M-165X needs about 1 cubic foot of air space. It would also require a new crossover design.

Thanks for your quick feedback, Danny.  I wasn't planning on starting working on speakers any time soon, but now I'm getting itchy.  Just have to get two other "small" projects around the house done first.  Or do I?.....

I have a demo pair of OB-5's (in rosewood) listed for sale here in my forum for a really good price if you're interested.

[ssabin]

Thanks for the info, Danny.

Right now is not the time for me to buy any speakers - the future home theater needs to be completed.  Studs are done, but I still need to construct soffits, move heating ducts, install electrical, cables, drywall, etc.  And all that probably doesn't even begin until I get the pool electrical and gas lines installed, and pool deck built.

So with all of those projects going on, I'm just thinking ahead to the HT, and how much of this do I want to DIY.  Being an EE, I thought I might try building my own amps and active crossover, but that would be a TON of work for 7 speakers, realistically.

Being that I see these demo speakers are in the Detroit area, I really should try to take a listen to them though.  But that might make the temptation to buy them too large, and I really have no suitable home for them right now.

[klh]

Since some have talked about doing a WWWWMTM cross between the OB5 and OB7 with four sealed M-165X's in the woofer section, would it be reasonable to do a WWMTMWW sealed/open center channel, too? My only concern is that's a really wide speaker. I'd be a bit worried about SQ off axis.

[Hank]

I have a request to quote on building a local customer a pair of OB-7's and I'm suggesting to him that they be MTMWWWW.  I really think they would look better aesthetically and be a bit less difficult for me to construct.  I"m also suggesting that he do a separate subwoofer. We'll see.

[Danny Richie]

I'll try to get the plans drawn up for the MTMWWWW design as soon as I can.