As I have mentioned in other posts, I embarked on a Spouse friendly Sub woofer DIY project. Pat, my wife agreed that if I could put my sub(s) in a cabinet that did not look like a speaker cabinet, and fit into the decor of our newly remodeled living room I could do whatever I wanted.
As we were looking for furniture, couches and the like, we kept an eye out for something suitable. We came across a set of three trunks that looked like they would meet my needs. Since I had three trunks and about 3,500 cubic feet of space I decided to do multiple subs with different specs. Some folks that know much more than I suggested this was a bad idea, one comment was it would dumb down the entire system to the weakest link.
I also discussed the problem with Brian Ding of Rythmik Audio, and he had similar concerns. He suggested that I attack different frequencies with the subs, so what I decided to do was build two 10" subs to handle the frequencies above 40 hz and 1 larger sub for freq's below 40hz.
The cabinets have a gross interior volume of .6 cu ft and 3.4 cu ft. So after looking around I chose the Titanic 10" drivers for my small cabinets and the new Rythmik Audio DS15 for the larger cabinet. I needed to determine the best way of powering the small subs. My problem was when I remodeled the living room I had prewired the areas where I expected to put speakers, but neglected any line level jacks. What I finally came up with was driving the small subs from a NAD amp I have and daisy chaining the DS15 off them.
I began ordering stuff, first the Titanics a BFD and some measuring equipment. I built the interior cabinet for the small subs out of 3/4" MDF. I did my cutouts in the interior cabinet first then glued the interior cabinets into the finished cabinets, using a edge trimmer/router to open thhe holes in the outer cabinets.
The cabinets went together in a weekend, and I was listening to them late Sunday night. Due to my not reading the info on the mixer I bought I did not realize it lacked Phantom Power and the ecm8000 would not work with it. So I exchanged that and by the next weekend I was testing. I found that I could get decent bass (flat) down to about 38hz, so things were looking good.
I ordered the DS15 and began building out the larger cabinet. This time I decided to glue the individual panels to the interior of the existing cabinet. I put the bottom and sides in and waited for the speaker & amp to arrive. I was up early on Thanksgiving and had the finishing touches on the cabinet after the turkey. Only one problem, I had used too much glue to attach the finished lid to the interior box. So I had to let the cabinet sit upside down over night so the glue wouldn't leak all over the cabinet.
The next morning I was ready to do testing, Pat had gone shopping so it was a perfect time. Unfortunately everyone went shopping with her, and I had put the subwoofer on a bay window sill with the help of my brother in law the previous evening, and I didn't want to try and get it down by myself (I estimate it weighs over 100 lbs). So I waited. When I finally started testing I had to convince everyone to move into the farthest part of the house. After about 3-4 hours of moving subs adjusting xover freq's phase knobs and setting up filters on the BFD I got a decent curve flat to about 15hz.
I promised some pictures in an earlier post. I warned that if I did my job right they would be pretty boring but here they are;
BTW The speakers on the window sill are some North Creek Echoes I built.
I would have more data, but I had a swiming pool pump go up in smoke, had to install blinds, and generally do familial stuff.... I will post more data soon... I haven't really had a chance to listen to the system as much as I would like.
I also want to do more testing under different configurations. What I have at the moment is the sub out of the receiver goes into a splitter, driving both channels of the BFD. The output of the BFD goes into the NAD power amp this drives the 10" subs. These subs have a steep natural curve at about 38 hz.
I ordered the DS15 with a 24 db xover. The DS15 goes pretty flat down to 15hz, so I just needed to match the DS15 with the 10s. I attached the amplifier in the DS15 to one of the 10's. I then used REW to match the level, phase and crossover.
The next test I want to do is to send both speaker signals through the DS15 amp and then back to the 10s. I will need to rebalance everything, but what I hope to gain is a high pass filter for the 10s. This should reduce the load on the 10s. It may also give me a cleaner xover and less filters on the BFD.
Over the next few weeks I will have little time, but I will post what I can as I can.
congrats on a very nice looking and clever solution to the decor problem! Just out of curiosity will look with a different eye at the next furniture place I'm in.
My only problem is the wife collects antiques, can imagine the look on her face when i proudly tell her how, with the help of her latest expensive purchase I managed to 'hide the sub'!..... " But I thought you'd be pleased darling!"