[cody69]

I am considering building the SW/PR-12A based sub listed on GR's website to compliment  my 2-channel A/V-1 system. The system is used exclusively for music, mainly blues and jazz at moderate listening levels. Configuration is pretty basic, CD source driven through Jolida 302 tube amp to A/V-1s.

Since I don't have any prior experience with subs, a few questions before getting started. My goal is to enhance the bass definition and increase the overall soundstage I'm getting today with the A/V-1s. And yes, I admit that part of the motivation is driven from the amount of fun and learning I gained from building the A/V-1s.

First, since I read conflicting views about using a sub for music, I would appreciate hearing  from others how the addition of a sub impacted the overall musical listening experience. What did you gain... were there any compromises.

How about connecting the sub -- my Jolida has a variable sub-out that I was hoping to use to power the sub (assuming Apex or Rythmic plate amp) -- will this work? And should I run the A/V-1s full range (my preference) or do I need to filter out the lows.

And finally, for my application I like the configuration with both drivers firing forward. Is there any sound degradation with this lay-out? Does anyone have any information on this style of enclosure? Is a matter of maintaining the overall volume, and if so, what type of bracing is needed?

Thanks.

[Loftprojection]

You almost sound like me a year ago!  I also had read that for music you don't need a sub and so on.  On top of it I have the A/V-3 which go lower then yours and which wont benefit as much as you from a sub.  Anyway, I was bored at home after spending my free time on building the A/V-3 so I decided to order Danny's sub kit and at least, if not for music, it would be useful for movies.  Well I was in for a big surprise!  Sure I'm happy to have the sub for movies but it is for music listening that I appreciate it the most.  The are some songs where the sub doesn't really add much to the sound quality but there are other songs where it just adds this low kick that tells you, man, I never knew this song was so "physical", wow does it sound good.  For example, Cassandra Wilson, she has several songs that have very low notes which you will make you wonder why you didn't get a sub before.  After all when you stop to think about it, the biggest difference between multi thousand speakers and low budget speakers is bass.  Sure everything else is improved but building a big tower speaker that will have great quality low bass is expensive.  Well I think the sub Danny designed gives me bass that can rival some preeeeetty expensive speakers.

For front firing, don't know if there is sound degradation but considering how satisfied I am with mine I wouldn't think so.  Look at the picture, I've installed mine firing directly at my listening position between my main A/V-3 speakers.  For my room configuration, it was the best position so I build it with both drivers firing to the front and I was really lucky that it sounds great there.

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=729&pos=20

[Danny Richie]

The sub will be a nice addition to your A/V-1's. You can run your speakers full range and set the sub woofer crossover to the 45Hz to 55Hz range and play with the phase adjustment a little and you'll get really good integration.

It really doesn't matter which way the drivers face. The low bass is omni directional. Aiming one of them toward the wall will give you a little coupling and added gain. I fire my PR's back toward the wall. Doing this might pick up the output by a half of a db or so in the 20Hz range.

The recommended box plans are easy to build and braces the box very well. It would be my first choice.

Either of those plate amps will work great and are ideal for this sub and PR combo. I think Rythmic has some with variable boost level control that will give you some flexibility too. If you get one from Apex tell Steve what it is for and that you want the one set with the boost level to be 2db in the 20 to 22Hz range.

[cody69]

Thanks for the responses, I'm sold on adding the sub, now I just need to decide on the cabinet design.

Loftprojection, my situation is the same as yours -- the long dimension of the sub enclosure needs to run parallel to the back wall, and will be located between the main speakers. That's why I am interested in the forward firing drivers as you have done.

Danny, given my room layout, if I use the recommended enclosure plans, it would result in the sub drivers facing facing left and right. If it truly does not make a difference, then its an easy matter to follow the recommended cabinet design. But if there is no appreciable impact on overall sound quality, I would prefer to go the same route as Loftprojection. I would maintain the same enclosure volume as in the recommended plans, double up the front baffle and add bracing similar as Loftprojection has done.

I really appreciate comments and suggestions from the experts.

[Daygloworange]

I run the PR sub, and have played around with it quite a bit. Mine is the standard layout, with the drivers on opposite sides of the box. I'm crossing it at 40 Hz with the Apex Sr amp with the resistor mod. I've run it paired with A/V 3's,  OB 5's,  OB 7's and some other small 2 way speakers. It integrates well with all of them. It is much nicer on 2 channel audio than the ported subs I've heard.

I prefer it with the active driver facing forward. If you have it with the PR facing forward, the attack is a bit softer. It's not the best way to run it. That's my only concern with running the two drivers on the same baffle firing forward at the same time.

I haven't tried it with both drivers on the front baffle though.

Mine was just built real quicky in a box with 3/4 MDF. I would recommend to build it thicker and heavier.

Cheers

[Loftprojection]

cody69, for mine I basically just calculated the dimensions to keep the same internal volume as Danny's plans.  I wanted it as low as possible to fit below my HT screen.  You'll see on the 3 pics below, I installed the amp in the middle section between the driver and PR.  I added two braces each side of the amp and I doubled the baffle so it is 1.5" thick.  I didn't do any comparison, obviously I only have one sub, but to my ears this "front facing" configuration sounds very very good, snappy, not soft at all.  Would it be better with opposite side facing, I guess I'll never know until I get bored again and decide to build a new one! 

http://www.audiocircle.com/index.php?action=gallery;area=browse;album=729&pos=21
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=729&pos=23
http://www.audiocircle.com/index.php?action=gallery;area=browse;album=729&pos=22

[Danny Richie]

Built as per Loftprojection's version will work just fine too.

Now let's get some room treatment in that room and see how good it can really get. 

[Loftprojection]

Now let's get some room treatment in that room and see how good it can really get. 

I know you bugger!    It's my winter project, you know, us folks from the north we have snow in winter not like you folks from the south so we don't spend our winter on the beach!   

[Danny Richie]

It usually snows down here at least once (a little) each year.    About 4 years ago we got enough to build a snow man.

[Daygloworange]

How big do the snowmen get in Texas? 

Cheers

[Danny Richie]

At my house, only about this big.

[markC]

Well then; I guess that confirms it...everything in Texas IS bigger!

[Loftprojection]

Haha, quite nice, judging from the surrounding, looks like you scraped everything around to complete the snowman!  By the way, the "Northern" way to build a snow man, when you have snow, is to start with a hand size ball of snow, roll it around the lawn to capture more and more snow until the ball is big enough for the base.  Then you do the same for a second and third smaller ball that you put on top of the bigger one for the body then the head.   Yours looks much more like a "real" man though!   

PS.  sorry cody69, we got a bit carried away with our small talk here, not very helpful for your original subject!

[Danny Richie]

Yea, yea, we build them that way too. I think we got a good 6" of snow that time. 

[cody69]

OK, thanks guys. Got some very useful information in this thread, that will definitely help me move forward. Soon as I make enough space in the shop and finish the dining room chairs I'm making, will have some downtime for this project.

Based on the feedback here, I'm thinking about a hybrid design, that instead of having the drivers on the ends like Danny's plans, or on the front face as Loftprojection, will angle the drivers at 45-degrees so the sound radiates outward and towards the side walls. Once I get them built, I'll come back with a review and some pics.

[Danny Richie]

You can aim them anyway you like, but sound will not radiate in the direction that they face. It will radiate the same in all directions just like when you throw a rock into a pond of water.

[tjt123]

If I were to build a double sub-woofer (e.g. 2 X SW-12A and 2 X PR-12A as you did here http://www.audiocircle.com/index.php?topic=28323.0), do I just build it as a single bigger box with twice the volume, or do I build it as two separate compartments each with the recommended volume of the standard published plans?

   -TIM

[Danny Richie]

I built mine as per the plans and with separate compartments.