New project ideas - small-room HT setup

[cjd]

So I'm getting pretty close to way too sick of the crap my first ever speaker project embodies, and right now they're my 5.1 HT speakers (well, technically I'm going 4.1 with my MTM's in the front and no center 'cause I got so sick of the others).

It's probably a fairly normally problematic room - narrow, short, barely space for everything. 6.5 inches doesn't quite fit between the screen and the wall on the one side, so narrow has to happen. Little to no baffle step needed.

So right now I'm thinking slightly modular. Lower woofer cabinet 18" wide and probably 28" tall, with a dome mid and a tweeter in a narrow little box that's basically 6" square. 8" woofer centered at one end of the cabinet means I can have the same relative TMW spacing placing the woofer cab vertically or on its side.

Something like this.



The idea here would be that these end up really close to walls if not right up against them. The concept is tossing around the thought of 4ohm RS225, RS52, one of the little Neo dayton tweets or similar. Think I can hit ~90dB sensitivity with this setup given how they'll be used. Cabinet would be pretty shallow (perhaps TOO shallow)

Surrounds, not quite sure yet - I have a low ceiling and I'm pondering somethign that actually sits in the wall/ceiling corner, maybe same mid/tweet and a RS180...

Thoughts? I wish I could redo the room, you know? But that just isn't gonna happen.

C

[BrianJ]

6" square? Just buy the Bose system and be done with it....(you know you want it)!!!
Bwahahahaha!!!

Seriously though, sounds interesting but I'm havin a little trouble picturing where the woofers go (?), and the whole set-up relative to the room. Got some pics of the room?

Brian J.

[cobbpa]

It goes against using the RS52, but the idea of the upper cabinet being identical to surround speakers seems appealing to me. Basically that would result in a passively-crossed bass bin & an optional woofer / mid crossover. The 4" Aurasound comes to mind, but with a small Dayton tweet it'd be similar to Zaph's design. Ummm...maybe something like this Tang Band? Not sure how big of a box those would want, but they're spec'd at 90 db efficiency. If those could dig down to ~80 hz in a smallish, even wall-mountable cabinet, then having an option for passively crossing to the 225 at a few hundred hz or so for better power handling up front..that'd be a pretty handy design, considering the goal of surround sound. Maybe even an RS mid could work, though they usually seem to want decently sized boxes. Is it possible? I have no idea, I've never actually designed a speaker on my own. It would definitely be a versatile design! It could be used as a nicely sized TM as surrounds, then as a 3-way up front. Having 5 identical cabinets & crossovers makes it easy to build s et, then add couple of bass bins & additional filters for the fronts. Slick. I could see the high-efficiency and small size appealing to some looking for nice computer speakers (i.e., me). I hope I'm communicating this idea right...sounds cool to me, not sure if it's clear though.

That idea of a woofer cabinet that can be oriented a couple of different ways is a cool idea; goes right along with my vision of extreme versatility :W . How are you picturing the center channel speaker of this design? Just the woofer and tweeter? That seems practical, although it'd give up some performance to you MTM...maybe with improved off-axis response though, right? I really am not too knowledgeable, just throwing around ideas for ya.

[digital desire]

Is there a 6.5 or 7 inch wwmtm set up? One like the large RS setup, but not so large.
One that might *look* sorta like the ht8's?
Would not look like your proposal though. Just putting down a wish list...
Then, you could have identical matching cabinets ala cobbpa. Maybe nat p's on top, and a pair of 6.5 or 7" on bottom.....
My room is probably similar to yours. Big aquarium takes up one side, so the whole HT setup is 9.5 ft wide, and some of that is taken up by a couch along a wall.

So far it is the wwmt for me, but I still have time. 8)

[cjd]

I've toyed with a 3 or 4 inch driver in an MTM up top - however, that really doesn't help them for surround duty and it causes problems with the center then requiring a different topology.

Substituting a smaller woofer for surround duty should still work - heck, could even be a couple. Keep the core TM in play still.

The room is 13 feet deep at the ceiling, 11.5 feet deep at the floor (18" deep half-height "shelf" along the back wall) and roughly nine feet wide at the back, fifteen feet wide at the screen wall (stairs are to the left at the back of the room, taking up that six feet). So the sketch is mains, L/R and center (fitting under my screen). They would be placed near if not right up against the front wall.

I'm not sure if I'll bother with something like this or not - this room just sucks SO much, but then that's just how the whole house goes as far as the space. Cheap quick construction to extract maximum profit from people trying to buy in an area they can't afford because it's just too damn expensive all around. And it's not even THAT expensive.

C

[digital desire]

CJD, you just described the mentality of my house also.

Mediocrity strikes again.....

[---k---]

C,
Isn't this the room with the IB? How are the current MTM's deficient?

[cjd]

Alright, I sat in the room with a ruler and after about five seconds was laughing at myself... so, this isn't gonna work. I had previously been mulling MTM's with a small 4" driver (Aura NS4-255-8D1 is at the top of my list just now) with a bass bin, and as suggested by cobbpa as well - I'm now back to this being the most likely workable candidate, with center channel complications being the only open issue right now (I want the tweeter on the top for the center).

Ryan, the RS150 MTM's work pretty well if I stuff the port (I can bottom them out even crossed to the IB way too easily if not stuffed - that one took me by surprise), but they're too wide. I could do different versions in a slightly narrower box OR a tapered box, and that option may be the way I go. But they're still pretty big all things considered. I'm trying to do something that others may find useful, not just me. The other speakers (ultra-cheap ones) are harsh and hollow, with some speech resolution issues.

I should probably also mention that I'm giving serious thought to attempting a DIY prism to get a constant-height setup, using the current screen height and going wider for 2.35:1 cinemascope, which may introduce slightly more width constraint as I try to maximize the odd space. I can leave the right side of the screen where it is and still see the left side from the left seat, so it may work out. Would end up being ~98" wide...

C

[---k---]

Wow, you bottom your MTMs. Interesting. And, I'm failing to see how your proposed bass bins are smaller, but hey whatever excuses you need to justify building new speakers. :roll:

I just wish that you would come up with some excuses I could use on my wife. She's not understanding my desire to build new bigger, better speakers

[cjd]

Oh, ignore the bass bins just now, going a different direction with the realization of things missed, so we'll see how they shape up.

It's not about total size (for example, I never understand how bookshelf speakers on stands count as smaller than towers of similar width, height, and depth...) When I say big, I mean they're rather deep, and a bit on the wide side for my situation. Probably near perfect otherwise though, so a variant may in fact be what I use. Probably a 2.5 way or 3.5 way though. Still not sure. Only time will tell. I'm looking for ideas, feedback, so we're all off to a good start so far.

Oh, and as for excuses: you having fun with the furniture? Certainly are putting together some good results. Your wife already knows what can be done DIY-wise. And if size is the issue, then work within those constraints. For your room, deeper speakers probably would work just fine, but wider might not. Budget can be a killer too, and for good reason. For me, it's just an "I want to, I've saved up, any objections?" thing. And the objections are easily dealt with when specific. And if it's a show-stopper, ya just accept it and back-burner things. Meanwhile you mull around a zillion concepts, talk about 'em, etc. Every so often propose something crazy. Want to demo the 3-ways at your place? bring a moving van, moving blankets, nice solid dolly (probably appliance type) and pick a day that works, we can arrange that.

[---k---]

You know, my wife isn't against new speakers because of cost, size, looks, or anything like that. She just can't wrap her brain around the fact that my current speakers are only 1 year old and I want to try something new. Putting on my Dr. Phil hat here, she thinks I'm never being satisfied with what I have and always wanting something differnt, just for the sake of wanting something differnt.

Thats probably correct, but is that so wrong? As my grandma aways says, I could be spending my time and money at the pub.

Okay, no more discussion of wives. Back to our regularly scheduled program.

[Habs4life]

Have you considered using the SEAS H1333 coax as a mid/tweet in a 3way?It appears to be ideal for HT with its controlled dispersion and lack of lobing issues.

[Brian Bunge]

Chris,

If we end up buying the house we're looking at I might have to actually downsize a little bit! I'd love to do something like Pete Mazz's arrays and front setup but maybe something along the lines of an WWMTMWW. I'll have to see what I can come up with.

The good news is that it'll be a lot easier to get a screen and pj than in the current house, which we are renting.

[cjd]

H1333 coax wouldn't fit the space requirements. It would also put the tweeter farther away from the screen than I want it to be for a center.

Brian, sounds like a fun project. You probably already have some vague idea how many project ideas I toss around and mull without ever getting off the ground. WWMTMWW's definitely wouldn't fit in my room, regardless, though that sure would be fun.

C

[DougyD19]

Ryan, the RS150 MTM's work pretty well if I stuff the port (I can bottom them out even crossed to the IB way too easily if not stuffed - that one took me by surprise), but they're too wide. C

I'm using the RS150 driver in the parts express .25 cubic foot box with no port. Using the Onkyo receiver to crossover at 80hz, they bottom out...but when I move the crossover point to 100hz, they don't bottom out anymore.

There is a huge difference on the distortion at higher volume levels. At 80hz, the RS150 distorts sooner due to more travel of the speaker. At 100hz, their is a lot less travel and it makes the RS150 a lot happier and you can crank the power more.

[cjd]

Yup, I think your observations are right in line with what I would expect out of the RS150.

I think for classic HT use, the RS180 makes as much sense (or more) than the RS225 for bass duties. Max SPL is quite similar, but F3 is 75Hz vs 50Hz and box size is less than half (2cu/ft vs .65cu/ft - both sealed). That could work out relatively well for surround duty.

C

[DougyD19]

I don't have a lot of experience with lots of different drivers, but I would never use a two way system to produce low hz bass and vocals. I think the travel on the motor is just too much for a speakers happy place and induces distortion.

For bass, I think a 3 way is a must, or a two way with a dedicated sub. I'm a newby....but just putting in my 2 cents.

[Outfitter]

Hey CJD, I hope that you didn't lose interest in this project and moved onto the big 3-way rs center!

Couple thoughts, I think that there are a number of people that have the same design goals as yourself, some may not have the same room constraints, but the small form factor is important. In example,-me, my first DIY project was only 8 months ago, but I came from very small WAF accepted speakers, to more traditional larger speakers, your rs150 MTM. Previously I was using Paradigm ADP surrounds, and gulp, Bose. Now, the LCR size is not the WAF problem, the room placement of those LCR, and more importantly the surrounds is the problem. My issue is with proper placement of large speakers away from boundaries, which force them out into an already cramped room.

I am inspired by your talk about the low BSC MTM with the Aura NS4-255-8D. I think that there are a number of people that would love to find a design that mimics the small form factors of commercial designs, that doesn't completely comprimise the audio.

What about taking this idea and turning it into a full surround idea? Using the Aura line of 3" and 4" drivers, maybe to help out the mains you use integrated TANG BAND W6-1139SG 6-1/2"? You could use the Aura NS3-193-8a and the dayton neo for surround duty, maybe even get crazy and design a dipole for the side surrounds ala the Paradigm ADP? I'm about to build Zaph's Slimline for my second attempt at small surrounds.

Take it for what it's worth.....just some ideas, but I think that a group of small format speakers for all 7 channels, using similar drivers and voicing done by the same crossover designer, allowing on-wall placement for surrounds, would be a huge hit. ;x(

[cjd]

I'm looking at the 4" for surrounds still - my own application suggests a design that tucks into the wall/ceiling corner, so it is possible that would provide enough loading to help out the 3" and make it a viable option here. Only way to find out is to build and measure.

The T-B, I'm not really sure how well it would work.

The big center is just a mental exercise, no way I'm building it. It'll be to tempt someone that really wants it to building it and measuring it properly, so I can put together a crossover proposal for it.

I have a bunch of cheap 4" drivers with a similar faceplate to the Auras, so the plan is to put together some tests and see what I see.

C

[Brian Bunge]

Chris,

I don't know if you ever mentioned it or not, but can you tell us what size room your building this system in?

[cjd]

Not easily...

I said before:

The room is 13 feet deep at the ceiling, 11.5 feet deep at the floor (18" deep half-height "shelf" along the back wall) and roughly nine feet wide at the back, fifteen feet wide at the screen wall (stairs are to the left at the back of the room, taking up that six feet).

Except that I'm not sure if 9 feet wide is right. It *just* fits a Futon in width.

C

[cjd]

So, I think I may be snagging some of those Auras to mess with. I like the frame shape/dimension allowing really close spacing - sure, I could look at trimming frames on RS125's or something (it's been considered) but they don't get me the capability for a simple MTM surround. So many things say the NS4 is the way to go, so I think that's pretty much settled.

I'm on to pondering "bass" modules for the front 3 and find myself looking at the surprisingly inexpensive Dayton DA175 - seems to have good distortion numbers for use in a 3-way and a great F3 in a sealed box (24L for 2) of 58Hz. Sensitivity means I might find 1-2dB of baffle step at most, which could be OK for the practically on-wall placement being considered. RS180 is always an option, or a single 8" or even 10" could work well. So toss some ideas out there if you have 'em.

Tweeters, an obvious choice is, of course, the lovely Vifa D26NC55 that's in an ever shorter supply. That's also a mark against it, as it would be somewhat nice to put something together that will be viable for a few months at least, in case anyone else wanted to build it. The really budget 3/4" Dayton Neo (ND20) could work pretty well as they're respectable on the distortion on the top end. The 22TAF/G (H1283) is really looking pretty good here, could cross at a point where spacing is fine with the (slightly) larger face (or even trim the face a little bit if it came to that). The 27TFFNC/G (H1396) is also very interesting as a possibility - its metal dome brother tested pretty well. Anyone else have thoughts in this area? The OW1 is interesting but not really budget-sensitive. The off-axis is just so excellent though... XT19 is similar in many respects and tempting for that alone.

C

[Outfitter]

Are you looking at the NS4-255-4D1 4" or the NS4-255-8D1 4"?

[cjd]

NS4-255-8D1

Actually, I've looked at both. Would likely use the 8D1.

C

[Brian Bunge]

Chris,

Too bad that Madisound won't drop ship as I could save you about $8 per NS4. For 1-2 drivers it's not much of a savings, but when you're talking about 10 or more...

Concerning the DA175's, they have pretty awesome bass response when using 2 of them. My dad's speakers use 2 of them in a 3-way MTMWW design and I've always been amazed at what they can do. Of course they're in roughly 52L ported, but they really do pound. I'd expect them to do quite well sealed as well.

I'd like to see you try either of the Seas tweeters only because I've not seen them used yet.

[Outfitter]

Hey Chris- Do you think it is a typo, over at Madisound both the 4 and 8ohm are listed at 84 dB. Does that sound correct?

[cjd]

At first blush it sure seems to be a typo, but run the T/S parameters (which are different for each driver) and they end up both at 84dB... Really not sure.

Brian - may be worth asking them anyhow as I'm only two hours away...? That's incredible savings! Not that I grudge them their livelihood, so...

[Brian Bunge]

Chris,

I didn't have time to call today but I did get in a quick email to Brian at Madisound asking if they could drop ship to you. I'll let you know what he says.

[Brian Bunge]

Chris,

Got a response from Madisound. Sent you an email with details.

[wmilas]

You know, my wife isn't against new speakers because of cost, size, looks, or anything like that. She just can't wrap her brain around the fact that my current speakers are only 1 year old and I want to try something new. Putting on my Dr. Phil hat here, she thinks I'm never being satisfied with what I have and always wanting something differnt, just for the sake of wanting something differnt.

Thats probably correct, but is that so wrong? As my grandma aways says, I could be spending my time and money at the pub.

Okay, no more discussion of wives. Back to our regularly scheduled program.

Can't help myself here. You might remark that you aren't satisfied and want something new. Then point out how (in a nice kidding way, not an evil way) who lucky she is that its something new speakerwise and not wife-wise

Is that a little too evil?

[cjd]

Yeah, that's something they (wives - husbands too, probably) always have in mind and you do NOT want to remind them of. Seriously.

Brian, I'll keep an eye out for the e-mail. I have an overzealous spam filter at the server lately so...

I do think I'm going to go with one of the Seas tweeters, just not sure if I want the larger dome and smaller faceplate, or the smaller dome and larger faceplate...

C

[Brian Bunge]

Basically it was just that Madisound will drop ship to you as long as I make the payment on my account. Sent you some pricing to look at as well.

If it's easier, send me an email and I'll respond.

brian at radhometheater dot com

[cjd]

Brian, I'm at work so I won't be able to do anything till this evening.

C

[Brian Bunge]

Chris,

No problem at all.

[cjd]

But... but... I don't want to work now, I want to go build speakers. :P

C

[Brian Bunge]

Yeah, I know the feeling....

[JonMarsh]

You know, my wife isn't against new speakers because of cost, size, looks, or anything like that. She just can't wrap her brain around the fact that my current speakers are only 1 year old and I want to try something new. Putting on my Dr. Phil hat here, she thinks I'm never being satisfied with what I have and always wanting something differnt, just for the sake of wanting something differnt.

Thats probably correct, but is that so wrong? As my grandma aways says, I could be spending my time and money at the pub.

Okay, no more discussion of wives. Back to our regularly scheduled program.

Try it this way- you're an artist- an artist of speaker creation, music reproduction- an artist doesn't stop painting just because they have a wall full of pictures- it's the primal need to create, to learn, to forge a closer approximation to reality. She's looking at it like speakers are just an appliance. For us, speakers are art.

this is coming from a musician and artist, or at least, that side of me...

Now, whether the spouse will buy into that or not is another matter- you're more likely to have sucess if you're other wise meeting their needs emotional needs in the relationship.

For more on that, try

Marriage Builders

Dr. Harley and his son and daughter know there stuff... try the EN questionaire, just for fun.

Oops, my psych background is showing...

NOW we return you to your regularly scheduled programming...

[---k---]

Can't help myself here. You might remark that you aren't satisfied and want something new. Then point out how (in a nice kidding way, not an evil way) who lucky she is that its something new speakerwise and not wife-wise

Is that a little too evil?

Ah, but I think you hit the nail on the head! You have to remember the female psyche. It thinks that if you are never satisfied with one thing, then you'll never be satisfied with anything. Its is speakers today, her tomorrow.

Actually, my wife (who by the way has her Ph.D in psych) and I have a wonderful marriage. I've very very fortunate, and she lets me get away with quite a bit - I mean, look at the monsterous sub I have. I think it was just played up a bit, because this is the internet. If I want to build speakers, she'll roll her eyes and question why, but will never say no, unless it put something in jeopardy.

Yeah, now back to regularly scheduled programming.

[cjd]

Ahh, you know... I got the psych stuff growing up a double PK, as dinner conversation often came 'round to their recent counseling efforts. Music of course came before they went back to school to become clergy, and I went to school for art. I always feel odd when someone at work discovers Keirsey or MB and I already know my MBTI is INTP etc... (none of them know about Jung of course)

Good thing about that, my wife KNOWS I need to have projects going, knew it before we married. Sometimes she gets the results so I think it works out. She definitely understands. She finally has her own project thing (knitting) which I just love, partly because I think such productive little pass-times are far healthier than gazing at the TV for hours on end (or computer gaming... erk - got me on that one)

Anyhow...

Um...

hmmmm.

C

P.S. What IS regular programming around here if not rambling threads that cover all sorts of topics? This marriage thing may be right up the alley of this project, as it's partly intended to be small-ish options in a world where there aren't as many as we might like. Or more specifically, THEY might like. We like big, right?

[---k---]

Hey, I would love to discuss finding my wife her own project! She could use a couple, especially during the winter. She just isn't the typical girly girl, so things like shopping are out.

[Brian Bunge]

To my wife, shopping is a sport. But her real passion is her job, Retail Sales Manager for Cingular. She was out on medical leave with migraines for almost 3 months and was about to start going crazy once they found a medication that actually worked and that didn't leave her doped up for hours. She couldn't wait to get back to work. And her new store opens hopefully within the week so she's been "cracking out" as she likes to call it. Mention anything business-related to her and she gets a contact high.

[WillyD]

Ooo...are either of you gonna get the iPhone? (do you get a discount?)

[Brian Bunge]

As a store manager she may get one (they all got BlackJacks) but I'll hold off for some time. She gets a discount but it is off of the full retail price, which usually is still higher than the 2 year contract price.

[cjd]

So, is it crazy to be considering a 1.8kHz crossover to allow me to go TMM on these?!

Probably, but...

Leaning toward the Seas 27TFFNC/G (H1396) right now.

C

[cjd]

So, an interest in a 2.35:1 (or 2.4:1) screen has me pondering all horizontal placement across the front stage now.

A TMM would mean I could place that anywhere, any time, and it could be used as "mains" just as easily as surrounds (or more complex surrounds - I'm pondering a trapezoidal MTM-ish thing and a low-slope crossover) - or more complex crossovers could be built to support "bass bins" up front and turn things into 3-ways...

This is really an annoying process in reality, all these options and ideas to evaluate. Fun regardless. Must be like kids in that regard.

C