[LAL]

Well, I have a confession to make. I have been working on a subwoofer for my adult son who will use it for home theater and music(mostly rock)to go with GR Research AV1+'s and AV1's. I thought it might be nice to have an all GR Research system. Since he is currently renting and may change locations I had to make one that was able to play well in large room without over powering a smaller room. I thought a high output 12" might be more versatile than a 15". I also wanted to build a no compromise cabinet. I have completed the cabinet. It is "double hulled" with the inner cabinet made from 3/4" Russian Birch glued and bisquited and heavily braced. The inner cabinet is 2.6 cu. feet net. The woofer faces downward and the PR faced outward on the front baffle. The outer "hull" on the sides is made from 1/2" MDF. The outer top is laminated from with the Birch and MDF. The outer top is separated from the inner top by a 1" hollow space. The outer sides are separated from the inner sides by a 3/4" space. I filled the empty spaces on the top and sides with sandblaster sand-over 50lbs of it. The  cabinet without drivers and amp weighs approximately 100 lbs. I veneered it in teak and it sets on solid teak legs on a veneered platform of of two 1/2" MDF pieces laminated together with soft glue. The woofer fires downward onto this platform.

So what's my confession? Ever since I started this project I have feared that the GR Research subwoofer and PR weren't going to be up to the quality of the cabinet. I have even spent some time figuring how I could retro fit the cabinet for alternate drivers in case my suspicions proved true. Well the drivers and PE amp(273 watts/8 ohms) are installed. I owe Danny an apology for doubting. This combination of drivers, amp and cabinet meets all my hopes. Its  a champ on music and handles home theater with all the power you could want in an average size room. For  comparison purposes I currently use an Adire Rava in my home theater(18' x 11" x 8' room with 6' opening to adjoining room) The GR subwoofer easily matches the Rava for music and there is no comparison for home theater. This sub will shake the room if you want it to, but can also be played without over powering the  room. The Lord of The Rings never caused it to complain audibly or to bottom out which can't be said for the Rava.

I also have a 15" Adire Tumult in a large sealed cabinet augmenting a pair of VMPS RM40"s in a large listening area. I substituted the new GR sub for the Tumult. It had no problem fitting in and quite frankly is all the sub I would actually need in this combination for music. No, it doesn't have the output of the big, expensive Tumult but in combination with the RM40's it is has more than enough output in a very large area for any type of music you can throw at it. And the output is deep, taut and tuneful. I could easily live with this in place of the Tumult in this context.

As you can tell I am really pleased with how this sub turned out. If I can I will post some pictures. I really am going to hate to give this up to junior. While the cabinet I made is large for a 12" driver I suspect that having a rigid well braced inner cabinet and lighter outer cabinet damped with sand doesn't hurt in producing a superior sound.  The lesson here is to not  make a cheap cabinet just because the GR drivers are relatively inexpensive. They thrive in the best cabinet you can produce. Being equally adept at music and home theater, what more could ask for, particularly at this price?

Larry

[Danny Richie]

Thanks Larry,

I really appreciate the feedback. Now if I can just upgrade those main speakers for you.  

I lot can be said for solid cabinets. I am a firm believer in that and often tell my customers the importance of solid cabinets.

I have also told them if they really want more output than one of our SW-12A and PR-12A combo's can deliver then use a pair of them and drive them off of one plate amp. The woofers are 8 ohms each so paralleling them on one plate amp is no problem. Now you have double the output.  

Larry I look forward to seeing some pics.

[Geoff ¥]

Larry

Wow , your cabinet construction sounds amazing. Do post pic's of this supurbly built & finished encloser.

I think Dannys Sub/Pr kit is a very good sub and only if more were to hear a properly built one, they'ed be flying off the shelf.

I am planning to pick up a pair of SW-12/Pr kits and just waiting for the ok on my bank statement. Seems to get spent as fast as I put it in their.

I look forward to your SW12 subs pic's and the teak is such a interesting exotic veneer that can be some what diffucult sometimes. Do post them pic's, cause it sounds like it looks ~{just "incrediable"}~..!

=======Edit:

Danny

Is the Non Servo 380-watt Rythmik Audio Plate Amp alright to use in place of the amp you recommend.??

I would assume so as it has the adjustable rum filter 14/20/28 and also Q. Using the 20Hz rum filter & low Q, it looks on the graph to be a little lower than that, like 18Hz or so, 24db slide.

I ask as I have 2 of these just setting.

Regards
Geoff ¥

[Geoff ¥]

Fricken double post.!

[MikeSRC]

I just built the GR sub using the Rythmik 350 amp in an 18" cube config.  The amp is a good match for the sub as it is essentially the same as the Apex one, it just adds the bass extension switches.  While the A/V-3s I have are rosewood, I did the subwoofer with the black ash vinyl from PE.  I only have a few hours on it so far, but as usual with Danny's speakers, I'm impressed.  Here's a picture (it's just near the A/V-3s for the picture - not the permanent location):

[Danny Richie]

Is the Non Servo 380-watt Rythmik Audio Plate Amp alright to use in place of the amp you recommend.??

Yea, it will be great. It is made by the same company that makes the Apex Sr. but adds adjustability.