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post #1 of 39 Old 01-19-2015, 01:40 PM - Thread Starter
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NWCgrad's Mostly DIY Basement HT

NWCgrad's Basement Home Theater Space - Basement of townhouse located in Frederick, MD. Will be in the location for next couple of years at least, have been here for 10 yrs (+/- time spent in Newport, RI and Phnom Penh Cambodia for work).


ROOM:
Seating Distance - 12-13 foot from screen
Ceiling height: 92"
Room width: 191"
Room depth: 250.5"


EQUIPMENT:

Projector: BenQ PE7700 (old as dirt, 720P)

Screen: 110" diagonal Vutec (Vu-Easy, BrightWhite screen material [1.5 gain])

Seats: Two FlexSteel recliners composing the single seating row and a couch off to the side, a third chair is moved into position for movies with families (me + 2).

Source Devices:
Oppo 103
Dual CS-515 turntable w/ Ortofon Super OM10 cartridge

Audio Control:
Marantz AV7702 preamp

Amplification:
L/R: Crown XLS 1500
C: AudioSource Amp One (bridged, 200 W)
Surrounds: Adcom GFA 2535
Front Subs: Adcom GFA 555
Rear Sub: QSC RMX 1850HD (bridged)

Speakers:
L/C/R: DIY Pi Speakers 4 Pi (w/ JBL 2226H/B&C DE250 drivers)
SR/SB: Yamaha crap (about to be replaced by DIY)
SR/SBR/SBL/SL Speakers: DIY Eminence (10CX/PSD2013S-8, custom XO) - in progress!!!!!

Subwoofer System:
Front: (2) DIY Eminence LAB-12 2.5 cu ft ported subs tuned to 22 Hz [HPF = 30 Hz, 4th order BW]
Rear: DIY Exodus Audio Maelstrom-X18" 5.9 cu ft sealed sub [HPF = 10 Hz, 2nd order BW]
PEQ/HPF Filters: miniDSP 4x4


Use: Listening to music (75%) and watching movies (25%). I typically listen to music critically in native format (two-channel or multi-channel, format driven) at -15 dB THX preference, subwoofers at +5 dB (speakers calibrated to 75 dB, F+R subs at 80 dB)


DIAGRAMS OF ROOM LAYOUT/SETUP:






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Last edited by NWCgrad; 04-16-2015 at 03:29 PM. Reason: Sold Khartago amp and replaced with Crown/Adcom amps
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post #2 of 39 Old 01-20-2015, 08:46 AM - Thread Starter
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Just got off the phone...my Marantz AV7702 should be on its way soon!

The **OFFICIAL** Marantz AV7702 Pre/Pro

Edit: AV7702 in house!

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Last edited by NWCgrad; 01-30-2015 at 12:29 PM.
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post #3 of 39 Old 01-24-2015, 07:10 AM - Thread Starter
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4 Pi Speaker Information - http://www.pispeakers.com/Prices.html

Primary build thread: http://audioroundtable.com/forum/ind...=16208&start=0&

Speaker Information:


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post #4 of 39 Old 02-03-2015, 07:46 AM - Thread Starter
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Working on the four surround speakers (7.1 setup). Information in my build thread: NWCgrad's 10” coaxial collaborative design







Rm layout with surrounds:


The red dot represents the position of my head. It is not perfect per Dolby due to the location of sliding glass door, but is pretty close. The LS/RS speakers will be on adjustable speaker stands, set above ear level (actual height TBD). The LSB/RSB will be wall mounted, at the same height as the LS/RS speakers.
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post #5 of 39 Old 02-08-2015, 02:07 PM - Thread Starter
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Bought two amplifiers to go with the Marantz AV7702:
1) Crown XLS 1500 (new) - Front Left and Right Speakers


2) Adcom GFA 2535 (used) - Surround Speakers


Long-Term Plan: Purchase 6 Crown XLS amplifiers to run full balances 7.2.4 system (already have QSC RMX 1850HD amplifier for subwoofers)
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Last edited by NWCgrad; 02-08-2015 at 02:08 PM. Reason: Added graphics to post
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post #6 of 39 Old 04-16-2015, 08:05 AM
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Wow, amazing. Keep posting updates.
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post #7 of 39 Old 04-16-2015, 03:31 PM - Thread Starter
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Quote:
Originally Posted by Sinclair Hannie View Post
Wow, amazing. Keep posting updates.
Thanks...I need to post some system measurements once I get everything dialed in. Update: Basement laptop has died, will have to get another computer to run measurements.

Approach to setting up subwoofer system: SIX (6) Seaton Submersive install and exceptional service from Mark Seaton
Quote:
Originally Posted by Mark Seaton View Post
IMO, if you have suitable external EQ for the front and rear pairs, get measurement software and a microphone like REW w/UMIK-1, or OmniMic and use the DSP to blend the front/rear subs and then let Audyssey handle them as 1 subwoofer output. If you go back to the run-down I posted, you can see the process, but for your case, here's the summary of the full process I would do when calibrating such a system:

1. set all subs to same electronic input levels with EQ/delay zero'd.
2. measure front pair of subs and save response
3. measure rear pair of subs and save response (same exact drive level).
4. Overlay the 2 responses and now measure all 4 with the same drive level again. Ideally the response would be ~6dB higher this way.
5. Adjust delay on the rear pair to maximize their combination, and most importantly get rid of cancellation.
6. Decide if any EQ should be applied prior to running Audyssey.
7. Run Audyssey.
8. Measure result.
9. Measure combination of sub with center, then sub + L/R.
10. Adjust subwoofer distance to get best blend with center then L/R.
11. Determine if any final EQ/shaping of the response is desired.
12. Enjoy.

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Last edited by NWCgrad; 05-04-2015 at 11:50 AM. Reason: Updated info
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post #8 of 39 Old 05-11-2015, 12:54 PM - Thread Starter
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FInally drug my main computer downstairs to play with REW and bass equalization with the miniDSP. There is no EQ on the mains.


Audyssey Variations (after optimizing bass to the best I could in the allotted time period):




Goal is to have the flattest response from 80 Hz to >10 kHz. Using the shaded area showing + 2.5 dB range is seems that the Flat is optimal. Will undergo extensive evaluations with a multitude of media (CD, DVD, Blu-Ray {movie and concert})to see if the flattest curve is optimal in my space. I like bass, so I added a house curve (which seems to start a little higher than 80 after Audyssey does its thing).
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post #9 of 39 Old 05-11-2015, 07:37 PM - Thread Starter
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Listening session tonight was not good. My miniDSP settings seem to have jacked up my gains. Could hear a buzzing from the subs even when music was playing. Not good!

Started over, minimized the number of PEQ cuts by the miniDSP to ensure minimal impact to gains settings. Final result was dead quite, no hum or buzzing!


New measurements:












a



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post #12 of 39 Old 06-05-2015, 08:28 AM - Thread Starter
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I am a very big fan of Wayne's work...the dude just knows how to get the most from the designs. I thought about going with the 2 Pi's for surrounds but just became obsessed with going CD based all around. I know Wayne actually recommends against CD's for the surrounds as constant directivity is not exactly what one should be shooting for movies, but since I am primarily a music guy I went that way anyway.

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post #13 of 39 Old 06-05-2015, 08:38 AM - Thread Starter
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Thinking of going with some DIY Atmos elevation speakers, very preliminary but looks like @Erich H has some excellent coaxials for the job. Want to avowing in/on ceiling speakers due to 1) low ceiling height and 2) strong spouse disapproval of the idea of ceiling speakers. I plan to move as soon as I retire from the Navy (projected 2018) and don't want to cut holes in my ceiling at this point. Current system kicks some serious butt so not terribly motivated to add Atmos - but I have the processor so only need to build 4 speakers (will dig out my old Onkyo AVR to serve as the amplifier (using multichannel in on pure direct to avoid all digital crap in the Onkyo), not elegant but free amplification. If I am happy I will start scanning eBay for another Adcom GFA2535 4-channel amp (they are pretty cheap and I like Adcom).


Room with proposed Atmos (reddish color speakers on the diagram):


Hope it all works out...no Idea of timeline at this point. Probably Fall at the absolute earliest.
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post #14 of 39 Old 07-03-2015, 06:49 AM - Thread Starter
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Since my rear surrounds are installed significantly higher than my left/right surrounds in my 7.1 setup I decided to re-run Audyssey as a 5.1.2 configuration. The rears are mounted in direct line with front L/R speakers about 6.75" from the ceiling directly on the rear wall. Speakers are 74.25" from the floor and about 38" above ear height (surround speakers to the left and right are about 4" above ear height).

After running Audyssey my preamp (Marantz AV7702) listed them as full range but with bass management set them at 40 Hz. They are about 6' from my primary listening position firing straight into the room (no downward tilt). I figured for ATMOS the 90 degree coaxial would be best if not aimed directly at the primary seats.

I had minimal listening time but the opening sequence of Unbroken was the best surround I have ever heard in my HT (could be placebo at this point). I will play around with XO settings and whatnot and settle in for more extensive listening in next couple of days.

Finally, looks like I will be headed back to work next week. Been off for way to long for medical crap. Glad to see light at the end of the tunnel, just praying it's not a freakin train!!!


Picture of speaker location:


Latest room layout:
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post #15 of 39 Old 11-11-2015, 08:30 AM - Thread Starter
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Been awhile, so its time for updates.


Update 1. The up-firing DIY Dolby Atmos project is at an end. After months of playing with position, angles (using a laser protractor), enclosures it is time to wrap it up. Basically I am not impressed with up-firing modules. I could purchase one of the commercial entities to try, but I know I am not going to keep it so it just seems wrong to buy one just to return it after comparing it to the DIY project.


The enclosure that worked the best for minimizing direct sound, and providing some noticeable Atmos effect, was one where I could block the direct sound via insulation.









Worked okay but was big and ugly. In the end I mounted the Volt 6's on the front wall about 3" from ceiling. I had to make a brace for the left speaker due to the wall being 5" further back than the left speaker (basement with bumpouts for water/gas lines to kitchen directly above).









Atmos sounded much better with this arrangement than as up-firing module. After the new year will add a second set to rear for a 7.2.4 set-up.
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post #16 of 39 Old 11-11-2015, 08:39 AM - Thread Starter
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The second update is the building of stands for the front Left and Right speakers (can be seen in the previous post). Wanted to get the CD approximately at ear height. I didn't really take any photos, but they are made of 2" x 10" material, which was nice as the height was perfect, but sucked due to rounded edges and warping of the raw material. After a lot of fussing, sanding, wood filling and Duratex they are complete.





Each stand will hold approximately 70 lbs of sand, I have not yet filled them but its on my to-do list.
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post #17 of 39 Old 11-11-2015, 08:43 AM
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Looking good man! How often do you get to play with the doll house in the background
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post #18 of 39 Old 11-11-2015, 08:51 AM - Thread Starter
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The third update involves sound treatment. Have not yet added any room treatment except for a roll of R-13 (15" x 32') placed behind the screen. After reading the thread on DIY Custom-Printed Movie Poster Acoustic Panels - cheap! (DIY Custom-Printed Movie Poster Acoustic Panels - cheap!) I am building several acoustic panels.


Plan:
Two 24" x 48" (w/3" OC703) panels to left/right of the screen (How to Train Your Dragon 1 and 2)
One 40" x 60" (w/4" OC703) panel above the stereo rack (Hobbit Trilogy)
Two 24" x 36" (w/3" OC703) panels on rear wall above CD/BluRay racks (Wizard of Oz, Breakfast at Tiffany's - wife's selection for buy in for the project)
Three 24" x 48" (w/3" OC703) panels around the space near corners (Iron Man 3, Captain America The First Avenger, and Guardians of the Galaxy). I have a lot of corners due to HVAC/closet bumpouts.


Design of posters (still in flux), will be 150 dpi.
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post #19 of 39 Old 11-11-2015, 09:11 AM - Thread Starter
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Final update, speaker stand build so I can get my rear surrounds off the wall (freeing space for the acoustic panels and Atmos speakers).

What they will look like:



Cutsheet for 48" x 96" sheet (using 18-ply Baltic Birch purchased at local wood supply store - Exotic Lumber, Frederick MD). Really nice stuff, did not find any voids in the cut material.

Note: For some reason the first column's pieces merged, should be four equal size pieces (13" x 10")
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post #20 of 39 Old 11-11-2015, 09:16 AM - Thread Starter
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Actual progress on the speaker stands, I had the woodshop rip the stock to width for all the pieces, I now only need to make a few crosscuts for final size. Easy Button approach!


I made the front/rear panels oversized so I can flush trim with a router. Makes it a lot easier in my mind.

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post #21 of 39 Old 11-11-2015, 09:20 AM - Thread Starter
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Quote:
Originally Posted by Molon_Labe View Post
Looking good man! How often do you get to play with the doll house in the background

All the time, its where I keep my Black Sabbath action figures.

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post #22 of 39 Old 12-17-2015, 05:00 PM - Thread Starter
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Quote:
Originally Posted by bossobass View Post
Thanks Abraham for the kind words and consistently good posting. It would be nice if you could also post some details of your system, on which you did a superb job. I'm sure your playback results are just as good.

Here are the brass tacks:

1) Signal chain: Flat to 3 Hz. Without this, there will be no success <10 Hz.

Here are some versions of signal chain using the required L/T configuration accomplished through various hardware options from the player to the AVR/Preamp to the signal shaper to the amplifier. All have a 2nd order LPF @ 250 Hz in line. NOTE The light blue trace is through a DCX using only a shelf filter, as some suggest using. Obviously, there can be variations of that single curve based on what AVR/Amplifier is used:



It should require no comment as the graph tells the story of how the final response will be influenced by what signal chain is employed.

2) Driver displacement: .01 liters per cubic foot of listening room. Example: 2000 cubes = 20 liters of displacement minimum. That requirement's met by employing 3 UXL-18s, 4 SI-18s, 6 SI 15s, 7 Dayton HO-18s, 6 Dayton 15 Ultimax, 7 SA-15s, etc.

Alignment: Sealed. Ultimate "efficiency" <20 Hz is determined by box size, but must be balanced with excursion protection, which is an investigation, like the signal chain investigation, requires careful thought and final testing and will be dependent on the parameters of the driver chosen vs the Vb chosen with caution being exercised against the need to alter the signal chain in a way that eliminates the bandwidth of interest.

Amplification: Approximately 5W peak per cubic foot of listening space. This is based on a system designed with proper signal shaping to mate the system with the room. This requires a fairly accurate measurement of the naked system response compared to the system response in-room, from which comparison the Room Gain profile may be determined. The input signal may be altered to affect a new system FR that's designed to mate the system so that the result is a flat response to the desired frequency. . It's assumed that the amplifier(s) will be supplied by the proper AC and that the system will be operated only by responsible persons after proper setup, calibration and limits testing in-room using the actual program source of interest.

Transmission loss calculation: A debatable subject when speaking about <100 Hz, but the losses will obviously vary by construction method. This is the part of the equation that most folks confuse with "a sealed room".

All of my own imperial evidence from 10 years of measuring suggests that how sealed a room is, regarding air tightness, is largely irrelevant. Contrary to conventional wisdom, a drivers motion does not affect a change in the ambient pressure of a room. Rather, the drivers motion creates a sound pressure wave that travels through the air in the room. The air in any particular room may vary in temperature and/or humidity which both effect the behavior of the pressure wave, but the differences in that variable are unmeasurable unless one lives in a tent in the woods in the mountains or some similar unrealistic and irrelevant extreme.

The gain from the rooms boundaries increases as frequency decreases because the longer the sound wave vs the distance to boundaries, the more interference becomes constructive and conversely, the less the chance reflections can be destructive. Using this premise to explain 'room gain', a completely enclosed room may actually have less room gain than one which is partially open. The pertinent factors are; Item 1) above, item 2) above, transmission losses in the bandwidth of interest, the coincidence of resonant frequencies of the structure with the BW of interest and the placement of the system within the listening space.

Transmission losses through the boundaries will determine how much gain you realize at any given frequency, assuming all of the above have been considered and executed optimally. Obviously, if half the pressure wave is lost through the boundary to outside the room, then only 1/2 can be reflected back into the room to continue reflecting as it decays.

In any case and regardless of one's personal opinions regarding the mechanics of the phenomenon known as "Room Gain", measured responses of systems taken outdoors at GP vs in-room from Ilkka, Ed Mullen, Josh Ricci, MKT, notnyt and myself in rooms ranging from <2000 cubes to >4000 cubes show that "Room Gain" begins around 30 Hz and continues to increase in a similar pattern as frequency decreases down to the signal chain rolloff, which then dominates in-room response at the lowest octaves.

Using 2000 cubes listening room and DIY boxes loaded with 4 SI-18s (21.2 Liters), MiniDSP, a "clone" amplifier, the system will cost < $2500. It will meet the 4 Hz in-room response requirement at a properly calibrated reference level in any room that size.

In my case:



ROOM: 3500 cubes
DRIVER DISPLACEMENT: 36 Liters (Formula suggests: 3500 X .01 = 35 Liters)
SIGNAL CHAIN: (FR shown in graph) Oppo BDP-105 as pre/pro/player ==> SEQSS analog signal shaper =>> clone amplifier version (2)
AMPLIFICATION: 2 amplifiers, each @ 9KW peak (18KW total). Formula suggests: 3500 cubes X 5W = 16,500W peak.
IN-ROOM results: (shown in graph).
Playback Accuracy at Reference Level graphed from the LP:

http://picasion.com/i/1VXeB/

This is the basic formula. It will work for any room. If more output is desired, more displacement/amplification is required, which is scaled at +6dB per 2X. The formula can be deviated from only if the desired bandwidth is truncated on the low end by design or by deviating from any single point of the formula.
Lots of great information in this post....tagging for future use.

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post #23 of 39 Old 03-22-2016, 07:23 AM - Thread Starter
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Latest change to the system, the addition of two JBL 4645B subs.



Running the 4 Pi speakers upside down to keep the HF driver height at the optimal level for seated utilization.
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post #24 of 39 Old 04-04-2016, 05:40 AM
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Great setup mate. How's it sound?
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post #25 of 39 Old 04-04-2016, 07:13 AM - Thread Starter
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Great setup mate. How's it sound?
Thanks, I think it sounds really good. The addition of the JBL subs was the final piece (at least for now). They pair really well with the 4 Pi mains, they don't sound like subs at all, rather they sound just like the bass from the 4 Pi's only they are solid down to 20 Hz or so in my room. I will break out REW soon and get measurements.

I also added a Behringer MIC2200/FBQ2496 stack for HPF and PEQ. The MIC2200 is all analog, so I avoid an additional analog to digital to analog conversion. So far, I like the Behringer stack a lot better than the miniDSP it replaced.

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post #26 of 39 Old 04-04-2016, 07:34 PM
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Quote:
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Thanks, I think it sounds really good. The addition of the JBL subs was the final piece (at least for now). They pair really well with the 4 Pi mains, they don't sound like subs at all, rather they sound just like the bass from the 4 Pi's only they are solid down to 20 Hz or so in my room. I will break out REW soon and get measurements.

I also added a Behringer MIC2200/FBQ2496 stack for HPF and PEQ. The MIC2200 is all analog, so I avoid an additional analog to digital to analog conversion. So far, I like the Behringer stack a lot better than the miniDSP it replaced.
Interesting. Isn't the FBQ2496 a feedback eliminator/destroyer?
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post #27 of 39 Old 04-05-2016, 06:30 AM - Thread Starter
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Yes, but it is also a two channel DSP that has a bunch of parametric eq bands per channel. I turn off the feedback destroyer function.

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post #28 of 39 Old 10-21-2016, 12:27 AM
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Impressive setup! DYI projects always impress me, and you were able to cover the lowest frequencies possible. Just amazing.
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post #29 of 39 Old 10-21-2016, 03:14 AM - Thread Starter
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Impressive setup! DYI projects always impress me, and you were able to cover the lowest frequencies possible. Just amazing.
Thanks, it always gets some looks by the movers (so far nothing has disappeared during a move, but I always have some excess equipment to donate to the movers when they arrive which may help).

Working on new mains now, movers will really hate them.



I expect a final weight of over 175 lbs each, probably closer to 200.. If my next tour is also in the DC area (likely for my specialty) then I have completed my last military move (3 yrs, 1 month, 11 days to retirement - not that I'm counting).
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What are you building now?

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