Beechnut

I'm sure one will be enough for doing 2-channel, but I know I'll try it anyways. Carl, think I'm going to build the F-20s first. It's not beneath me to bring both of the dang things in the house, watch a movie, and then cart them back to the garage.

Thanks for sharing your results with us Derrick. So I guess there is no fear on its ability to pass the signal through with no noticeable degradation in the frequency response. Great find!

Thanks for the tip on the fan. So, I'm thinking of building two subs with the hope of someday being able to bring them in the house. The current system is an aesthetic stretch for my lovely bride. Once we end up in a home with a dedicated room, I'm sure she won't be to worried about large subs. If I build two in the meantime, pair them with my lascalas on another system without the ability to do room correction, while still using the QSC amps. As I understand it the suggested amps for most of these builds have DSP. I don't think the QSC amps do. So how do you add it, and still use those amps?

MLO, This is what a 3 prong to 2 prong connector does. It is a ground lift. That article is on point! XLR is 3 wire and a ground lift makes it 2. If you have a mic plugged into the mixer, and the mixer is running 3 prong, and the XLR doesn't have a ground lift in it, it is also running 3 wire and making multiple paths to ground. (Current can go over neutral to earth OR over ground to earth, through the chasse) Throw in a ground lift on the mic, and now current doesn't have multiple paths anymore. The only way any current in the system can get to ground is through the mixers 3 prong power cord.

Thanks for the advice. As far as EQ goes, wouldn't my AVR, working as a pre/pro, be able to do that? My RSW-15 has knobs & dials on it, but they are all set to null values, as I've just let the AVR's Audyssey do the math. Think I have it limited between 20hz - 80 or 100hz. Can't remember.

Babadono, He's only trying to get rid of DC hum. An AC/AC transformer won't allow DC to pass between the coils. Doesn't take an expensive transformer to eliminate DC hum/noise/current. It's just how transformers work. I'm not sure what the advantage of the high dollar ones are. Frequency response (like you said), durability, quality of materials, efficiency. Love to see some REW tests on it. (Just using the image to show schematic of a transformer. Don't get hung up on mutual inductance and equations/formulas)

Yup. A lift switch does the same thing as a 3 prong to 2 prong plug. Creates a single path to ground using the neutral wire.

Remember, Neutral and Ground (White/Green) both go to the same spot in your circuit panel (bonded together as stated earlier), which is coupled to an earth ground. If the item uses a 3 prong plug, it has two paths to chose from to go to your earth ground at your box. When you have multiple paths, you create the potential for a ground loop. Your AVR, Amp, Bluray, etc, etc are your multiple circuits. You can't assume all grounds have the same potential either. Different lengths/gauges of wire will have different resistive values. Here is a snipit from Episode 134 of Ham Nation where Bob Heil takes a moment to explain ground loops. You don't want to UNGROUND your system! You just want to setup one path to ground. https://www.youtube.com/watch?v=oUJLE7sKbp0 Who is Bob Heil: http://en.wikipedia.org/wiki/Bob_Heil

I would think on paper & in theory, not having them on a solid foundation would diminish the response in the room. But would it be discernible to the human ears and the listening experience...dunno. You could make 5 separate platforms instead of a stage. That way you could place the 2 subs on the floor, test out the listening experience, then place them on the platforms and test again. Since the floor is carpeted, you could try the spikes on the bottoms of the platforms, to help couple them to the floor better. I know both types of speakers are heavy enough to ensure spiked feet will press down to the slab and not walk on you.

You want all of you equipment to have a single path to ground. When you use 3 prong wires on several or all items, this creates multiple paths to ground, thus inducing a ground loop. So when using them, you have to think about the entire circuit and place them strategically. Don't use them on ALL items. Derrick, that item you put up doesn't call itself an isolating transformer, but I think that is what it is. Basically its and AC/AC transformer, which because of it's very makeup, the DC hum doesn't make it through the process.

Youth, My RSW-15 gets boomy if I tuck it in the corner. It lessens when I give it room to breath. 18"-24 from each wall in the corner. Since you are brainstorming, have you tossed around the idea of not putting them behind the false wall at all. Maybe on center of your side walls. Might be a lil tight walking room I'm sure, but hey, you have a dedicated room for tinkering =+) BTW, congrats on tracking down 2 maple RSW-15s! Quite the journey I'm sure.

Agreed NOS. You know what's funny, if you go to your breaker panel in your house, open up the door and then open up the thing where you can see the wiring that goes into all the breakers, and to the ground bus, you'll see something funny. Black = Hot White = Neutral Green = Ground The white and the green are connected to the same ground bus. If some piece of equipment on that circuit is inducing current onto either neutral or ground...this can be a source of hum that is heard. And it will effect EVERYTHING on that panel. Some stuff just doesn't care. Now, I'm not an electrician. So this is just friendly advice and steps I've taken to avoid ground loops in my ham radio equipment. It isn't the only solution. It is 1 step of a very frustrating process to eliminate background noise, hum, etc. The real solution is getting current off of neutral and ground. GFCI outlets pop when there is too much current on ground. Breakers do the same thing. Once the amperes get past a certain threshold, the circuit opens.

Derrick, Do you have any 3 prong to 2 prong adapters laying around the house? That is one way I've isolated some ground loops when working with ham radio.

Could I use one of these for a Tuba HT or Cinema F-20? I have one available for the low low price of FREE, so that is why I'm considering it. It is a pro amp, with no unbalanced inputs. But I'm thinking a sub-out isn't balanced anyways, so I should be able to just go RCA > TS 1/4" Phono....then us speakon for the inputs to the sub. Link & Specs below. http://qsc.com/products/power_amplifiers/plx2_series/PLX1804/ PLX2 Series FeaturesAll models Very light weight ("02" models, 21 lb/9.5 kg, "04" models 13 lb/5.9 kg). Cooling design exhausts hot air out the front, keeping the rack cool. Flow-through heat sinks require no filters that could become clogged. Front panel LED power, clip, -10 dB, and signal present indicators for system monitoring and troubleshooting. 02 models also feature bridge and parallel mode LED indicators. Two Speakon® NL4 output connectors provide positive-locking speaker connections. Upper connector provides both channel outputs on all four poles (Channel 1: 1+, 1-; channel 2: 2+, 2-) for bridged mono or for single-cable connection to bi-amplified speakers. 21-position front-panel gain controls for precise, repeatable amplifier adjustment. Balanced XLR inputs with parallel TRS connectors accommodate all common input connectors and support loop-through operation. Patented PowerLight power supply technology with other patents pending. 04 models Value combined with uncompromised PLX technology, quality and performance for applications that don't require bridged or 2-ohm stereo operation. Two models with power ratings up to 900 watts per channel @ 4 ohms. Clip limiting protects speakers; thermal limiting maintains operation even during abnormal overloads.

Derrick, I'm going 60" or 65" so our current one has to go. The Salamander stuff looks great too. Budman that is a nice website. Great options all. Thanks for the help. I'll get this narrowed down soon.

Those are gorgeous pieces by standout designs. Tasdom, I've thought of taking your route but putting the TV on the wall behind it. Any other furniture options out there?

Going to change up the home theater furniture. Moving up to a 65" screen and the old one won't work. I'm trying to avoid putting the TV on top of the 64 and avoid the 64 up above, like it is now (see profile). Anyone have ideas? This is what I'm interested in. http://www.martinfurniture.com/collections/entertainment/MP/index.php

I went with the 900 over the 1100 for the traditional ergonomics. These are superb products! One of my favorite gadgets I've ever picked up. Once I got it programmed its been set and forget. Even the wife appreciates it.

I made sure i picked a receiver with it to help integrate two subs in the future.

I know the room calibration white noise is a broadband sound unlike a specific 20hz tone, etc. so I guess I could see how once you step away from the broad tones an isolate them, you could get the db differences, even if they started out with the aggregate at the same level. Thanks for all the updates. We have some smart folks here.

Youth, you started the test by setting both of them at the same SPL I'm assuming? Taken from main LP with both subs in their cabinets? Does room gain make it louder? Just weird if they both started at the same db.

Only way I could open up my RSW-15 full throttle would be outdoors!!! I like loud but I can't even rock 1/2 without worrying about the integrity of everything on my walls, glass windows, small figurines etc... Disregard hearing =+)

Youth I love that you have a room that is dedicated to HT and really gives you a good standard that you are familiar with to plug and play new items! Book of Eli is one of the movies I use to demo also. The scene in Inception where Leonardo is sitting with the girl in front of the resteraunt, where the dream starts to fall apart is another. And had my folks over and we watched War Horse, very cool LFE battle scenes. All visitors were overly impressed! I think is is really good for HT and amazing for music. People get hung up on the black and white numbers. The experience speaks for its self. Let alone having a dedicated room with treatments. I can't wait to get to that point and get even more performance out of it come that day!

I was originally gonna save for a PB13 Ultra. But at $2K, when the RSW-15 came along for $750 (I think), figured I'd jump into it and come back to the SVS later. Honestly, if I get my own room, I think the wife will not be as concerned with aesthetics and I may go DIY. That F20 is physically huge but sounds so promising.

Subscribed! I was planning on supplementing my RSW-15 with a "HT" sub latter in life when we have a dedicated media room. Totally looking forward to hearing about your experience. I jumped right into this sub from a passive Bose module of course I was blown away. I've since heard a SVS pb12 ultra/2 in a forum members home and I know there is a difference. That's why I say it is good for HT and many would be happy forever. But that SVS was phenomenal!