DIY HT sound...questions/build thread

[cobbpa]

Alright, this thread is going to start out as a way for me to try and ask some questions and then (around Thanksgiving) start holding pictures of the build process for the room.

Back story:
My uncle wants a multi-use home theater area. He has purchased a Mitsubishi projector and is working on details for the room. It will be in a basement and used for HT purposes as well as general get togethers; my large family loves Ohio State football and will definitely be watching a lot of games in this room. It is a good sized room; not sure of exact measurements but I'd guess 20'w x 40'd x 9' h with an opening to the rest of the basement for the back ~15' of the left wall. Buying speakers to fill a room like this seems expensive. Here is where this forum and thread come in.

Value (budget) is a definite consideration for this setup. Thusly, I have helped my uncle choose DIY speakers to try and fill this room. We are planning on using the RS 3 way towers, WMTW center, and Modula MT speakers for a 5.1 setup (may be bumped to 7.1). The Seas tweeters will be used all around. Any initial thoughts on these speakers in this type/size of room? Obviously vocals are key in such space & for football viewing. We have not discussed sub options yet. An AV receiver will be used but amps for the mains & center are defnitey possiblities.

Some concerns crossed my mind since the speakers will be placed nearish walls, but with the depth of the front shelf, I don't think it will pose too much of a problem. The Modula surrounds will have to be very near wall, but the depth of those might make them acceptable there. I'm not sure if we can wait to hope for a non-BSC version--we will likely buy components next week if PE has a sale for the DIY event. That's a lot of money to save with this kind of project.

I have attached a sketch my uncle made to show the proposed front layout. The screen is planned to be 100". You can see some questions he has. I am thinking the center channel would be better on the shelf than above the screen so the tweeter is closer to ear level. Also, the enclosure on the right to house the tower speaker is a no go, right? I think he put that there since kids will be running around most of the time, but I'm guessing speaker grills will be protective enough.

Hopefully this can generate some interest & discussion; feel free to give any input!

[rumatt]

I can't help with many of your questions, but I'm also interested in some near-wall surrounds, as described in this thread

In this post Thomas says he and Jon may cook up some non-BSC designs, but it wouldn't be until the second week of October if it happens at all.

this post summarized the designs I was able to find on possible smaller surrounds based on the RS150 driver. Some are intended to be near-wall.

[derekbannatyne]

Why not use that shelf as the sub? Is it just an enclosed box or is it open to any other rooms?

[Marzen]

At the risk of being a diy killjoy, I recently checked out a similar HT but with Maggies and a pair of big sonotube subwoofers. Vocals were AMAZINGLY clear and detailed at EVERY point in the room as was the stereo image and steering. I also attended a HT meet last week where the host had a pair of Martin Logan ESL's and an SVS sub. It too was a narrow (but smaller) room and had the same impressive clarity throughout. I'm reconsidering my own basement HT plans to go a similar route and reserve my diy designs for 2 channel music only. I just don't think I can top the above setups for the same price range considering they were run off a mid line HT receiver.
Assuming you build your own sub(s) and screen, you could save quite a bit and be up and running very quickly for a reasonably low investment. I was also surprised that a screen with a gain of 3 paired with a digital projector had such a bright detailed picture with no hot spotting. There were wall washer lights on up front and some lamps in the back of the basement on with no apparent washout on the screen. Enough light to read by, let alone eat or just wander around and talk. You can build a screen using stretcher bars like these at UltraTechArt . Good luck with whatever route you take; and Go Buckeyes!!!!
-Ward

[ThomasW]

I spoke with Jon this morning. He'll be in Denver for a week of vacation. The plan is to create nonBSC crossover versions of the Modual TM, MTM and NatP while he's here. This will be around the middle of the 2nd week in October.

My advise is buy everything except the crossover parts for the Modula speakers at the sale.

[cobbpa]

rumatt:
I did see your thread & was interested, but I'm just not sure if the 150 would be enough in this room, even on surround duty. We may end up modifying the Modulas down the road.

Derek:
Yeah, I'd thought of that. We just haven't discussed sub stage. Does anyone know if cancellation issues might be of concern? I also debate whether to put the components on a rack in the stage or if the displays would be distracting. Behind that shelf will be a hallway, so there could be an access panel.

Marzen:
Thanks for the input. I believe we will stick with DIY; being able to alter the crossover may end up being advantageous in this scenario. I hadn't read about the Maggies until last week and they do look interesting. I'm thinking / expecting vocal distribution to be of little concern since game-watching will likely be done in all channel stereo and the center seems to be getting good reviews. I would like to hear something like the Maggies though. Have you heard the RS towers or center?

Thomas:
I agree. If he goes 7.1, we could probably get some quantity discounts on that purchase too. Do you agree the center and main placement shouldn't present a problem in concerns with BSC?

[ThomasW]

Do you agree the center and main placement shouldn't present a problem in concerns with BSC?

BSC issues will be present whenever the speakers are closer that ~2' to a boundry

[Marzen]

Marzen:
I would like to hear something like the Maggies though. Have you heard the RS towers or center?

I haven't heard the center posted on here as I don't use a horizontal CC, but I've used the RS series 315HF, 225, 180, 52, & 28 in several builds for LCR & surrounds. All of which sounded very good for music but didn't quite cut it for HT usage. I'm thinking it may just be that I'm partial to dipole speakers for HT use; although I've never heard cone driver based dipoles so I don't have a reference to compare to the above mentioned planar/esl types. Thomas could probably share some insight on the difference between dipole vs monopole speakers for movies & tv since he has both. This recent discovery (epiphany?) was something of a diy let down for me, but I'm equally excited to have found a solution that packs a huge wow factor for myself. I hope you find the same. :T
-Ward

edit: Oh yeah, Penn St got beat down!!!

[BobEllis]

Don't you guys know that you're rooting for the wrong team?



LET'S GO BLUE!

[Marzen]

Jeez Bob, that's SO offensive I'm gonna have to flag your post as such. So there. I'll meet you back here on Nov 18th.
PS: nice PhotoShop work there.

[BobEllis]

That's from the U of M site - today's game. Not my photoshopping. I date back tothe Bo-Woody years. See you in November.

[cobbpa]

I've started to put together my BOM for the towers to purchase during the sale this Saturday. My uncle said he's okay with spending a little extra on crossover components in the front 3 speakers, so I'll go for Mills resistors and would like to use some film & foil too. The trouble is, I don't know exactly where to use the better caps; I'm assuming the tweeter xover & high pass section of the mid, but am not experienced enough to know which one on the mid schematic would be most effective ops:. Also, one BOM uses some inductors from Madisound. We will be purchasing all of our parts from PE, so just to check compatibility:

Sledgehammer steel laminate ---> I-core
Sidewinder Inductors-----> Jantzen 15 gauge aircore

Right?

[cobbpa]

Edit: Full BOM further down. I core inductors removed & a small change of 100uf caps. I'll leave this here for a sort of all-PE BOM for those who may find it useful. Total after these changes is $464.65 before tweeters.


Part Number In Stock Description Qty. Price Ext. Price Remove
266-550 No 1.0mH 18 GA. "I" CORE INDUCTOR .. $6.30 $12.60
266-558 Yes 3.0mH 18 GA. "I" CORE INDUCTOR .. $8.32 $16.64
266-800 Yes .10mH 18 GA PERFECT LAYER INDUCTOR .. $3.72 $7.44
005-1 Yes MILLS 1 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
005-10 Yes MILLS 10 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 14.00
005-4 Yes MILLS 4 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
005-6 Yes MILLS 6 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
005-3 Yes MILLS 3 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
255-220 Yes JANTZEN .33mH 18 GA AIR CORE INDUCTOR .. $4.28 8.56
255-224 Yes JANTZEN .40mH 18 GA AIR CORE INDUCTOR .. $4.50 $9.00
255-424 Yes JANTZEN 1.20mH 15 GA AIR CORE INDUCTOR .. $13.72 $27.44
027-447 Yes DAYTON DMPC-100 100uF-250V POLYPROPYLEN .. $19.51 $78.04
295-362 Yes DAYTON RS150S-8 6" REFERENCE SERIES SHI .. $28.55 $57.10
295-366 Yes DAYTON RS225S-8 8" REFERENCE SERIES SHI .. $40.80 $163.20
027-922 Yes JANTZEN 3.9uF 400V CROSSCAP CAPACITOR .. $2.48 $4.96
027-930 Yes JANTZEN 8.2uF 400V CROSSCAP CAPACITOR .. $3.76 $7.52
027-936 Yes JANTZEN 15uF 400V CROSSCAP CAPACITOR .. $5.13 $10.26
Subtotal: $444.76

[derekbannatyne]

Are you building the Seas or RS28a version? You don't want to use iron core inductors, I've heard they bring alot of problems that the steel laminate and air core inductors don't have.

[cobbpa]

Seas version.

I'll modify to remove iron cores; I thought they were fine in woofer sections. My mistake.

[rumatt]

Which seas. H1212?

[cobbpa]

Yes.

[Jim Holtz]

Seas version.

I'll modify to remove iron cores; I thought they were fine in woofer sections. My mistake.

Here's what you're looking for http://www.partsexpress.com/webpage....7&WebPage_ID=3 or the Jantzen 15 gauge air cores would be great too http://www.partsexpress.com/webpage....626065#15gauge since you're getting a 20% discount. The lowest DCR will be best for the big value inductor on the woofer section of the crossover.

Jim

[cobbpa]

Jim, the first link you posted didn't work, but I'm guessing it's pointed to the Erse Super Q inductors?

[Jim Holtz]

Jim, the first link you posted didn't work, but I'm guessing it's pointed to the Erse Super Q inductors?

Yes. It was supposed to point to the Erse which is what I'd use for that particular inductor. I normally buy Madisounds but with a 20% discount the Erse will be a good value.

Jim

[cobbpa]

For the center, the working schematic has a 17 ohm resistor pair & a 12 ohm pair. What values should I combine to get these? I can't tell what values chasw used to build these. Input? Also, what values would be good to combine for the 40 ohm resistor? I didn't see any Mills resistors of 40 ohms & they're out of 20 ohms too. Dayton does have a 40 ohm, but I'd like to stick with Mills for this..

[ThomasW]

http://www.mhsoft.nl/RP.asp

Might want to bookmark the main page

http://www.mhsoft.nl/spk_calc.asp

[cobbpa]

Does this infer it's always better to parallel high-value resistors than use lower-values in series?

I think I'll use two 82 ohmers for the 40...1% tolerance, but is this close enough? It's the first resistor on the mid section.

[ThomasW]

I'm not sure using a Java script calculator infers anything....other than calculating paralled values is a bit harder than adding up resisitors wired in series...

Paralleling gives higher power handling than running them in series.

I think I'll use two 82 ohmers for the 40...1% tolerance, but is this close enough?

It's fine ...

[cobbpa]

K, thank ya thomas, this actually answers a couple questions I've had for a while now, just didn't have the context to ask. Good deal! Big purchase tomorrow.. :dancenana:

[truckman]

Paralleling gives higher power handling than running them in series.

Nope, power handling is the same with either topology.

[cobbpa]

Welp, here it is. 2 towers, a beefy center, 2 Modulas, and the woofers of 2 other Modulas (all sans tweeter, the Seas H1212). It'll be 7 speakers and the 2 back modulas will likely be hung from the ceiling a little in from the wall & angled downward slightly; I felt that the currenty design incorporating more BSC is a better choice here.
Not that this BOM is useful to many others, but it's a key part of our build process. Larger inductors, Mills resistors & Jantzen caps in the mains & center, Dayton caps, resistors & the smaller inductors to the Modula surrounds.


004-2 Yes DAYTON DNR-2.0 2 OHM 10W NON-INDUCTIVE .. $1.25 $2.50
004-6 Yes DAYTON DNR-6.0 6 OHM 10W NON-INDUCTIVE .. $1.25 $2.50
004-8 Yes DAYTON DNR-8.0 8 OHM 10W NON-INDUCTIVE .. $0.98 $3.92
027-408 Yes DAYTON DMPC-0.68 .68uF-250V POLYPROPYLE .. $0.85 $1.70
027-418 Yes DAYTON DMPC-3.0 3.0uF-250V POLYPROPYLEN .. $1.67 $3.34
027-421 Yes DAYTON DMPC-4.0 4.0uF-250V POLYPROPYLEN .. $1.85 $11.10
027-430 Yes DAYTON DMPC-12 12uF-250V POLYPROPYLENE .. $3.55 $7.10
027-436 Yes DAYTON DMPC-20 20uF-250V POLYPROPYLENE .. $4.95 $19.80
027-458 Yes DAYTON DFFC-0.47 .47uF-400V BY-PASS CAP .. $1.38 $4.14
266-912 Yes ERSE SUPER Q 3.0mH 16 GA 500W INDUCTOR .. $13.89 $27.78
266-924 Yes ERSE SUPER Q 4.7mH 16 GA 500W INDUCTOR .. $14.76 $14.76
005-1 Yes MILLS 1 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
005-10 Yes MILLS 10 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $14.00
005-20 No MILLS 20 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
005-30 Yes MILLS 30 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $3.50
005-4 Yes MILLS 4 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
005-6 Yes MILLS 6 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $7.00
005-8 Yes MILLS 8 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $3.50
005-82 No MILLS 82 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $10.50
005-3 Yes MILLS 3 OHM 12W NON-INDUCTIVE RESISTOR .. $3.50 $10.50
255-026 Yes JANTZEN .25mH 20 GA AIR CORE INDUCTOR .. $2.75 $5.50
255-036 Yes JANTZEN .50mH 20 GA AIR CORE INDUCTOR .. $3.50 $7.00
255-202 Yes JANTZEN .10mH 18 GA AIR CORE INDUCTOR .. $2.85 $8.55
255-220 Yes JANTZEN .33mH 18 GA AIR CORE INDUCTOR .. $4.28 $8.56
255-224 Yes JANTZEN .40mH 18 GA AIR CORE INDUCTOR .. $4.50 $9.00
255-232 Yes JANTZEN .56mH 18 GA AIR CORE INDUCTOR .. $5.18 $5.18
255-250 Yes JANTZEN 1.00mH 18 GA AIR CORE INDUCTOR .. $6.65 $13.30
255-260 Yes JANTZEN 1.50mH 18 GA AIR CORE INDUCTOR .. $8.61 $8.61
255-270 Yes JANTZEN 2.50mH 18 GA AIR CORE INDUCTOR .. $10.98 $21.96
255-424 Yes JANTZEN 1.20mH 15 GA AIR CORE INDUCTOR .. $13.72 $41.16
027-447 Yes DAYTON DMPC-100 100uF-250V POLYPROPYLEN .. $19.51 $39.02
295-364 Yes DAYTON RS180S-8 7" REFERENCE SERIES SHI .. $30.74 $122.96
295-366 Yes DAYTON RS225S-8 8" REFERENCE SERIES SHI .. $40.80 $244.80
027-910 Yes JANTZEN 1.0uF 400V CROSSCAP CAPACITOR .. $1.09 $1.09
027-920 Yes JANTZEN 3.3uF 400V CROSSCAP CAPACITOR .. $2.07 $2.07
027-922 Yes JANTZEN 3.9uF 400V CROSSCAP CAPACITOR .. $2.48 $4.96
027-930 Yes JANTZEN 8.2uF 400V CROSSCAP CAPACITOR .. $3.76 $7.52
027-936 Yes JANTZEN 15uF 400V CROSSCAP CAPACITOR .. $5.13 $10.26
027-950 Yes JANTZEN 56uF 400V CROSSCAP CAPACITOR .. $14.81 $14.81
027-956 Yes JANTZEN 100uF 400V CROSSCAP CAPACITOR .. $23.59 $70.77
027-928 Yes JANTZEN 6.8 uF 400V CROSSCAP CAPACITOR .. $3.42 $3.42
295-372 Yes DAYTON RS150-4 6" REFERENCE SERIES WOOF .. $28.55 $85.65

[cobbpa]

If anyone is interested, here's the guide I made to help show my uncle what kind of speakers DIY can produce. I realize I make some generalizations & that I probably have a couple of technical slip ups, but it accomplished the task of showing some designs and helping us choose what's best for the room. Also, the prices were estimates and I guessed at some quantity discounts, so they probably are off in some cases.


I don't know how long the link will last, but if anyone thinks it's worth keeping around, go ahead & host it if you want--fine by me. I'd had the thought that it may help others decide what to build without wading through multiple long build threads. Give it a look.
Conversely, if you're someone who's picture I used and you'd like me to remove it, just say so.

[JonW]

... and the 2 back modulas will likely be hung from the ceiling ...

Be a little careful here. No chance would I hang mine. They're turning out much heavier than I would have guessed. I'm overengineering my cabinets and going a little overboard on bracing, etc. But they're really heavy, even though they are small MT speakers. Also my house is quite old, so finding a strong place to hang from isn't too likely. If your speakers turn out lighter (quite likely) and you have stronger points to hang from, it could work. Just a note of caution. Good luck with it. Sounds like a super fun project.

[ThomasW]

It'll be 7 speakers and the 2 back modulas will likely be hung from the ceiling a little in from the wall & angled downward slightly;

As has been posted several dozen times, none of these speakers have crossovers designed for on-wall or in-wall use..

[cobbpa]

As has been posted several dozen times, none of these speakers have crossovers designed for on-wall or in-wall use..

Right; we're waiting to buy the parts for the 2 surround Modulas as they will need low/no BSC, but went ahead & are using the current crossovers for the surround back. Maybe I should clarify their position.

I think the plan on the rear surrounds is to hang them from the ceiling (yes, very carefully & securely jonw :W ) probably ~2 feet in from the side wall. Picture the speaker hanging about a foot straight down (like it would on a string) and facing straight forward. Now turn them in a little and face them slightly downward. This, at least, is my understanding of it. Seemed like the current crossover would be better in this scenario. Or am I still wrong?

[ThomasW]

Correct, I suggested you to wait on purchasing the crossover parts for the rear speakers until Jon has a chance to run a new design specific for on-wall mounting. That will occur late next week or early the week after.

The design as posted is specific for the speaker sitting on a stand 2' or more above the floor and 2' or more away from any boundry or combination of boundries.

Any placement near-wall, on-wall, in-wall, near-ceiling or whatever, needs the new yet to be developed crossover

[WillyD]

Jon has a chance to run a new design specific for on-wall mounting

Will Jon get a chance to design a new 3-way center in the next 6 months, possibly using the RS52?

[cobbpa]

I see. I thought since these didn't have any direct reinforcemnt behind them, they'd be best for the regulars. I understood the side surrounds definitely need the new version, wasn't sure on these 6th & 7th. Oh well...they aren't in an extremely important spot..and parts were 20% off today It'll do.

[ThomasW]

Will Jon get a chance to design a new 3-way center in the next 6 months, possibly using the RS52?

A 3-way center with the dome has been discussed, but it's a low priority right now.

While he's in Denver my agenda is to get modified or non-BSC crossover designs for the Modula TM, MTM and NatP. That way I can avoid having to answer placement questions over, and over, and over....

We don't design new speakers when he's here in Denver because his $pendy speaker testing rig lives in Calif. However to some extent we can modify existing designs since the in baffle measurements were done for the original designs. And for in-wall designs the mfgr's stock plots can be used.

...they aren't in an extremely important spot..and parts were 20% off today It'll do.

Then don't post complaints about the performance.....

[JonW]

While he's in Denver my agenda is to...

... finalize the Arvo design!
:B

That's what you guys really want to do, isn't it?
:P

(Just kidding- I realize how busy you guys are. Heck, it's taking me ages to make a few teeny speakers.)

[cobbpa]

Alright, now that most parts have been purchased (I enjoyed taking out a case of woofers) I might as well put up a few "before" pictures. Hopefully this kind of shows some of the dimensions & such. I've tried to describe them in a sense that builds on on after the other. So read and enlarge/look at the accompanying pic, then move on..kids. :

The picture with the tape on the floor is from standing in the stairwell. The tape represents where walls will be. Well, there'll be a door to go down the hallway that will be made by the rest of..the tape. ha

The second picture is from what will be the center of the room. The nearest tape section represents the wall the screen will be on. Behind the screen is a hallway, leading to a bathroom in the back right corner.

Third pic is from what will be the rear of the theater area. Possibly a half wall or bartop here to divide the theater area from the kitchen area. Any ideas on how to create some sort of seperation without excluding those cooking & eating in the very back of the room?

Next pic is the left side of the staircase. This will be rec, play, etc. area. The furthest area away will probably be divided off to house the slotcar track and some random storage.

Last pic is from the back of the staircase looking at the kitchen area, clearly. It kind of gives you the idea of the size in the rear of the area, as this is the only pic of the back wall.

Make some sense? If you look at the sketch in the first post, it may help too.

[WillyD]

A 3-way center with the dome has been discussed, but it's a low priority right now.

While he's in Denver my agenda is to get modified or non-BSC crossover designs for the Modula TM, MTM and NatP. That way I can avoid having to answer placement questions over, and over, and over....

We don't design new speakers when he's here in Denver because his $pendy speaker testing rig lives in Calif. However to some extent we can modify existing designs since the in baffle measurements were done for the original designs. And for in-wall designs the mfgr's stock plots can be used.

That makes sense. :T

[cobbpa]

Well, my cousin and I got to work on the Modula (full BSC) crossovers yesterday. They didn't turn out pretty, but they'll do . Today, I got on the networks for the towers. They also turned out well. Nothing new or exciting, just some capacitors and inductors, but if anyone sees any problems or concerns, say so! We are in no rush of installation, so there's time to correct.

[cobbpa]

A couple of advancements on this since I last posted:

My cousin runs a framing crew & brought some equipment in town. We spent a couple of days trying to get as much done with the free labor! Also, my uncle has talked to his contractor and they will finish the framing & begin other tasks (drywall, carpet, kitchen installation, etc.) soon. This weekend, after exams are over, I'm heading up to Chicagoland to build all 7 speakers with my cousin. Should be fun! I finally got an account on a photo hosting site, so here are some pictures of the framing work in the basement.

[cobbpa]

Lots of progress this weekend with the speakers. Most cabinets mostly built.

Images not available

More pictures up at the site linked in the above post too.

[---k---]

Those WWMTs look great so far. You ever going to have these up and running in Chicagoland. I would love to hear them sometime.

Also, shoot me a PM. If iirc, you're only about 15 minutes away.

[cobbpa]

Ryan, I'd like to share them, but I'm not actually located in Wheaton. My cousin lives there and we did a lot of the work together, since it's his dad & he's a better woodworker than I am. I'm up there severeal times a year; I'll have to get in touch to stop by next time.


A lot of progress has been made on the room..plumber's finishing up, electricians are moving right along and drywall is supposed to start going up soon. They're going to do the screen first so we can watch our Buckeyes on a nice big screen on Monday.

Time for me to go finish up the in-wall Modulas!



Image not available

[cobbpa]

Things have really progressed since the last pictures I've put up. Well, the room has...not so much the speakers, but here's 3 pictures showing what the room is like. It's all open behind where I was standing to take the pictures. The two openings on either end of the 'stage' will hopefully end up housing a couple of subwoofers. The Modulas for the two back channels are complete and we are hoping the front three will be in use by Saturday afternoon!

[cobbpa]

Speakers & room are coming together. Tomorrow speakers will be complete, carpet should be done, and the couch is arriving. Awesome
Still don't have a way to hang the 6th & 7th speakers, but we're working on that.