SWithey DIY Dual 15” Subs – Down to 15Hz

[swithey]

So they are all 720x1280 models. To me that makes them all essentially the same and IMO the difference between them become moot by running them so large.

You room diagrams look to put you about 10.5 ft from the screen, from a 128" screen displaying 720x1280. I implore you to seek out a 720 setup on 128" and make sure that is going to be ok with you. I have not seen 720 that big, I have seen a few 120" at 720 with $10-15k projectors and did not find them to be very pleasant looking. I am way more picky than most people when it comes to video, so a YMMV disclaimer is in order here :T

KJP,

You are correct and thanks for reminding me. My plan is to get the projector and a white drop cloth and see what works for me. Once I decide on the size, I plan to build my own DIY screen. I'm sensitive to SDE and “blockyness” too. Unfortunately, my budget does not allow for one of the really high-end projectors. 9' wide may be pushing the envelope for my seating distance but I will not know for sure until I see it myself.

BTW -- By chance, do you own a CRT projector?? Most CRT guys are very ciritcal of their video. bpape is one of those guys.

[ThomasW]

Yo dude, CRT projectors RULE! .....:wink:

CRT will continue to rule until SED becomes a viable option.

Both Evil Twin and I own CRT projectors and feel they're the only projectors to own.

And some of us, thanks to the good people at Dtronics, are watching the Toshiba HD-DVD at native 1080i through our CRT projectors..... :B

[swithey]

Yo dude, CRT projectors RULE! .....:wink:

CRT will continue to rule until SED becomes a viable option.

Both Evil Twin and I own CRT projectors and feel they're the only projectors to own.

And some of us, thanks to the good people at Dtronics, are watching the Toshiba HD-DVD at native 1080i through our CRT projectors..... :B

Yes, I've read they do perform quite well. Seems every time I go to a B&M store their only CRT projector is either broken or needs calibration (at least that's what the sales guys tells me). So it has been challenging for me to demo one in the right setting and calibrated so it looks as good. But if WAF and budget were different, I would consider one myself.

[---k---]

And some of us, thanks to the good people at Dtronics, are watching the Toshiba HD-DVD at native 1080i through our CRT projectors..... :B

Me Jealous.

[chasw98]

Yo dude, CRT projectors RULE! .....:wink:

CRT will continue to rule until SED becomes a viable option.

Both Evil Twin and I own CRT projectors and feel they're the only projectors to own.

And some of us, thanks to the good people at Dtronics, are watching the Toshiba HD-DVD at native 1080i through our CRT projectors..... :B

Yes, DUDE! CRT's rule. But just like Ferraris and women, they need maintenance. Where do you get replacement CRT's?
Toshiba HD-DVD.... Seen it with Serenity, The Last Samurai and Pride & Prejudice. I'll wait for another year.

(Serenity was pretty damn good looking though! Are you listening to the HD soundtracks and do they sound better?)

Chuck

[Evil Twin]

As much time as I spend doing the Emperor's bidding, I can only wish to have sufficient viewing time to impact the operating lifetime of my CRT projectors. I have an NEC 9PG+ with about 900 hours, and a complete set of brand new OEM tubes to replace that. It is dedicated mostly to TV on DVD viewing.

I also have an NEC 10PG (9" tubes) in the process of being seutp, which has about 500 hours of use. At my typical usage rate (10 hours per week for movies), it will last about 20 years. I, on the otherhand, may not last that long.

[ThomasW]

But if WAF and budget were different, I would consider one myself.

Can't do anyting about the WAF. My NEC XG cost $2500 second hand. Tubes are quite nice with well under 3000hrs on them.

Where do you get replacement CRT's?

Takes a long time to rack up enough hrs on a CRT to need replacement tubes (10,000 hrs if the PJ is properly set up). But if/when needed they're available from VDC. I may do like Jon and buy a 'spare' PJ to tide me over until S.E.D. is a viable option

Are you listening to the HD soundtracks and do they sound better?)

I have an older processor so my choices are limited to standard 5.1 DD or DTS.

[dyazdani]

KJP,

You are correct and thanks for reminding me. My plan is to get the projector and a white drop cloth and see what works for me. Once I decide on the size, I plan to build my own DIY screen. I'm sensitive to SDE and “blockyness” too. Unfortunately, my budget does not allow for one of the really high-end projectors. 9' wide may be pushing the envelope for my seating distance but I will not know for sure until I see it myself.

FWIW - I just bought a Sanyo Z4 LCD PJ - I'm running it at 720p on a 92" screen. My viewing distance is about 13 feet. I am probably 3 feet beyond the point to where I can barely notice any SDE. I don't see a good situation with a 128" screen at 10.5 ft, at least not with my LCD. Not sure on what you had in mind for equipment.

[KJP]

KJP,

You are correct and thanks for reminding me. My plan is to get the projector and a white drop cloth and see what works for me. Once I decide on the size, I plan to build my own DIY screen. I'm sensitive to SDE and “blockyness” too. Unfortunately, my budget does not allow for one of the really high-end projectors. 9' wide may be pushing the envelope for my seating distance but I will not know for sure until I see it myself.

BTW -- By chance, do you own a CRT projector?? Most CRT guys are very ciritcal of their video. bpape is one of those guys.

LOL, I was until my Sony 1272 died last fall..... :cry:

I'm not going to fix it. Instead I am saving pennies to buy a 9incher :banana:

I'll run that on the same 72inch screen I pointed the 1272 at. Viewed from 9ft.

Cant wait. :drool:


I am glad to hear your plan on screen size. Your room is going to be awsome, you WILL enjoy the heck out of it I'm sure.

[swithey]

FWIW - I just bought a Sanyo Z4 LCD PJ - I'm running it at 720p on a 92" screen. My viewing distance is about 13 feet. I am probably 3 feet beyond the point to where I can barely notice any SDE. I don't see a good situation with a 128" screen at 10.5 ft, at least not with my LCD. Not sure on what you had in mind for equipment.

My wife and I actually visited a few model homes today to look at Media Rooms. One actually had a half decent setup. The projector was a Sharp XV-Z12000U 1280x720 DLP (MSRP $12k) and it was projecting on a 10' wide 1.78:1 Stewart Microperf screen. The second row of seating was at about 12' away and SDE was not visible --- however, moire was awful. However at that distance, 10' wide was just a tad too big. I think 9' wide (at least for 1.78:1 material) is probably the way I will go. It will also increase my room for speakers on the side of the screen. BUT -- I reserve the right to change my mind pending the "drop cloth test" :W

[swithey]

Guys,

Been busy on the HT and about the get started on my DIY speakers and the IB setup with (4) SoundSplinter RL-P15s. I plan to hook these to a Behringer EP2500 and a Behringer DSP1124P Feedback Destroyer Pro.

Should I get the 2ohm or 4ohm version of this speaker? I've heard there are positivies and negatives each way. The "speaker level" cable distance from the amp to the woofers will be about 20-25'. I was planning on 4ohm but wanted to be sure.

Getting really excited!

[vitod]

I've seen people use the D2 for single boxes and sonotubes and the D4 in IB's. But I think it makes little difference.

SteveC...chime in. :B

[saweetnesstrev]

Swithey where do i find your demo discs in your site,, i dont think they are there,,

[swithey]

I've seen people use the D2 for single boxes and sonotubes and the D4 in IB's. But I think it makes little difference.

SteveC...chime in. :B

I went ahead and ordered (4) 4ohm models. He was out of stock on the 2's -- so it made the decision quite easy I should have them by the end of next week.

[swithey]

Looks like I will soon be embarking on my IB sub for the HT and wanted to see which config you guys liked better. The IB area behind the front wall is attic space at ~ 385cu/ft. The actual HT room is 14.5 wide x 19.5 deep x 8’-10 vaulted ceilings at ~2550cu/ft

I will be using (4) Soundsplinter RL-p 15s D4

Here are the specs:

Qts: 0.447
Qes: 0.508
Qms: 3.728
Fs: 27.487 Hz
Re: 6.1
Ls: 5.303 mH
Lp: 6.268 mH
Rp: 12.39
Dia: (% shift) 330 m 37.5 %
Vas: 148.8 L
Mms: 231.4 g
Cms: 144.8 u
Bl: 21.90 T*m
n0: 585.0 m
SPL: 89.67 dB
Sd: 0.0806 m^2
Xmag: 27.4 mm
Xmax: 24.6 mm

Option #1: Dual 19” x 19” x 21” Deep with 2 drivers in each manifold
Option #2: Dual 29” x 29” x 21” Deep with 2 drivers in each manifold

Image not available

Option #3: Single 42” x 19” x 42” Deep with 4 drivers
Option #4: Single 30.5” x 19” x 42” Deep with 4 drivers

Image not available

I leaning toward Option #3 or #4

Any help would be appreciated.

[ThomasW]

Option #1 is the one I'd use.

[swithey]

Option #1 is the one I'd use.

Thanks for the quick response. I do have a question -- I've had others tell me that you want a larger manafold so you can get away from creating a bandpass sub. From my limited knowledge, a bandpass sub does not go as low as a true IB sub. Now.. where is the line where a bandpass becomes an "true" IB sub, I don't know