Jump to content
The Klipsch Audio Community
Sign in to follow this  
CECAA850

25Hz Tapped Horn

Recommended Posts

After more time listening to them in my small basement HT 5.1 system, I'm more impressed than before. My old DIY KEF B139 TL subs are on their way to the dumpster (only the MDF cabs, not the drivers).

These small subs got me hooked on tapped horns. For a brief time I was considering building another large TL using the B139s. Then I thought about trying to use the B139s in a tapped horn. The more I learned, the less that idea appealed to me. What makes a good woofer for DR, BR or TL does not make a good TH driver. I'll probably sell my two pairs of B139s on eBay and put the proceeds toward proper TH drivers.

The trade-off in this TH design is sacrificing SPL to get a relatively small footprint. Two of them easily provide all the SPL needed in my situation, so naturally, I'll probably build two more.

Edited by DizRotus

Share this post


Link to post
Share on other sites

I thought about building a couple more. By I'm really wanting to try a f-20. I love these little guys but you can't beat the effortlessness of a huge subwoofer. After having this kpt-884 upstairs for a week or so now I just miss what a large subwoofer can do over these little anarchy guys.

Share this post


Link to post
Share on other sites

The more I listened to 2 channel and HT using these, the more I missed them in either situation when not in use. Since I never listen to music and movies/TV at the same time, I decided to move the 2-channel to the small basement HT space so the ATHs could perform double duty.

I just ordered another pair. Four of these will provide all the clean low bass I'll ever need.

Edited by DizRotus

Share this post


Link to post
Share on other sites

The new pair of flat-packs and drivers arrived today. Finding time to assemble them and finish both pair is the problem. Eventually, photos will be posted.

Dealing with Erich of DIY Sound Group is a pleasure.

Edited by DizRotus

Share this post


Link to post
Share on other sites

Congratulations

Share this post


Link to post
Share on other sites

ive debated 2 more but i have decided to just put mine away for now till i move then prolly put them under my bed for a small bedroom home theater. i think i am gonna build a couple big subs for my living room. i am so spoiled with my subs downstairs i cant stand not having the same for my upstairs living room. at least thats my plan in my head till the wife shuts it down lol

Share this post


Link to post
Share on other sites

Liking the big sub is just part of Klipschitis. Start out with reasonable size speaker and next thing you know is that you have more speakers than all your friends, bigger speaker than everyone you know and you can't buy speakers at regular stores because they are two small. I think this call for a CAT scan and blood work.

Share this post


Link to post
Share on other sites

I managed to break one of the binding posts. Erich at DIY Sound Group is sending a new pair of posts. I can't finish rough assembly until the new posts arrive.

I'll post some photos this weekend of the progress to date. The plan is to get the new pair all the way to Duratex and then swap them for the first pair that's still bare plywood. That way, I can listen to at least a pair until all four are done. When that day arrives, the decisions regarding placement and amp configuration begin. I 'm leaning toward using a separate Dayton 240 plate amp for each pair wired in parallel. That way, each amp sees a nominal 4 ohm load.

Share this post


Link to post
Share on other sites

Some in progress pics.

The first pic shows a closeup of the woofer before the sides are glued in place.

The second pic shows one all glued together (bottom) and the one that awaits a replacement binding post.

The third and fourth pics show the enclosure after using the router to round-over the corners. I decided to prime the bare wood to eliminate any issues of the Duratex not adhering to the Loctite PL and/or Bondo. After sanding the primer, I'll apply a coat of flat black to cover the grey primer. Last will be the Duratex.

 

EDIT: 12/20/2015

 

Photos deleted to free up server space.

Edited by DizRotus

Share this post


Link to post
Share on other sites

The second pair is now done and in service.  The first pair is now in the garage to have the round-over done to the corners, nail holes filled, etc. prior to primer, black paint and Duratex.

 

The photo on the right is one of the second pair and a DIY BR single driver, also in Duratex.  The photo on the left is one of the first pair.

 

When I decided to buy a second pair, I left the first pair (unfinished) in service while I completed the second pair.  Last evening we watched some movies using just the unfinished pair.  The performance of these continues to impress.

 

This morning I brought the completed second pair into the small basement HT so that I could hear all four prior to removing the first pair to be finished.  Using two Dayton 240 plate amps modified with low and high pass filters specifically for these subs, at the recommendation of Lilmike, the designer, I must admit I was disappointed.  Four sounded no better than two.  More subs don't produce lower notes, but should increase SPL and impact.  I wasn't feeling it.

 

After removing the rough pair, I was still disappointed by the sound of the second pair.  Part of me was grasping at a need to "burn in" the new drivers as the explanation, but I've never put too much stock in that notion.  

 

Eventually I had an epiphany.  My good idea to stuff the throats with newspaper during the sanding and painting, had outgrown its usefulness.  Its amazing how much better a tapped horn sub sounds when not strangled by a wad of old newspapers. Now I'm eager to again hear what four sound like, but it will have to wait until the second pair is completed.  I'm too lazy to carry them down and back up just to test them.

 

I love Duratex.  It's not for everyone.  I wouldn't want it in my living room, but my better half would never let this stuff in her living room anyway.

 

EDIT: 12/20/2015

 

Photos deleted to free up server space.

Edited by DizRotus

Share this post


Link to post
Share on other sites
My good idea to stuff the throats with newspaper during the sanding and painting, had outgrown its usefulness. Its amazing how much better a tapped horn sub sounds when not strangled by a wad of old newspapers. Now I'm eager to again hear what four sound like, but it will have to wait until the second pair is completed. I'm too lazy to carry them down and back up just to test them.

 

That's too funny.  Sounds like something I would do.  Are you putting one on each wall?

Share this post


Link to post
Share on other sites

My good idea to stuff the throats with newspaper during the sanding and painting, had outgrown its usefulness. Its amazing how much better a tapped horn sub sounds when not strangled by a wad of old newspapers. Now I'm eager to again hear what four sound like, but it will have to wait until the second pair is completed. I'm too lazy to carry them down and back up just to test them.

That's too funny. Sounds like something I would do. Are you putting one on each wall?

I'll experiment with various combinations of amps and placement when all four are done.

Right now they're in corners with the mouths facing into the room. I'll try having the mouths face the corner, two in front, two in back, etc. any suggestions?

Edited by DizRotus

Share this post


Link to post
Share on other sites

Not sure what the "Costner" is.

 

According to a Harman white paper, the most uniform coverage when using 4 subs is one centered on each of the 4 walls.  Next best is one in each of the 4 corners.  If both of those scenarios are impractical, I'd center 2 on the front wall and 2 center on the back wall.

 

Tapped horn mouths shouldn't face the walls or corners.

Share this post


Link to post
Share on other sites

Costner is iPad's auto correct gone unnoticed.

Where is this white paper of which you speak?

EDIT: Never mind. I found it. Thanks for the tip.

Edited by DizRotus

Share this post


Link to post
Share on other sites

Carl,

 

The Harman paper (attached) doesn't seem to address my small irregular shaped  space.  As the attached drawing illustrates, my space is very small in the corner of a semi-finished (in place when I bought the house many years ago) basement.  The back wall is drywall over 1" foam board over block foundation.  The left wall is wood paneling over 1" foam board over block foundation.  The right wall is drywall over studs.  The ceilings are exposed joists.  There is thin carpet directly on the cement floor.

 

The paper assumes a rectangular room, which mine is not.  It also speaks to optimizing averaged bass for several seating positions, which doesn't really apply.  There are rarely more than two people on the couch at a time watching movies.  Critical 2-channel listening is done by yours truly seated on the couch in the center.

 

More than once the paper said, "The LF factor still goes down when more subwoofers are used."   The trade-off is improved averaged bass over a larger listening area.  In my situation, that's not important.  For practical purposes, there is only a single listening spot.

 

So far, the bass is excellent for music and movies with 2 subs as shown in the drawing.  When I get the other two working, I plan to place them (without newspaper in the throats)  directly in front of the existing pair, which I assume will have the effect of essentially doubling the effective size (surface area) of the subs.  I expect them to play louder; not lower.  The configuration of the room doesn't lend itself to wall placement or a sub at each corner.  With the subs in the corners at the front, they also function as stands for the small single driver BR enclosures.

 

It would not surprise me if using 4 subs in this space doesn't offer a significant improvement over 2 subs.  With 2 subs, I can listen to music or movies at more SPL than needed or desired.  If 4 subs seems to be over-kill, then I'll send the second pair and an amp to my brother or one of my sons.

 

Multiple sub placement has probably already been addressed in other subwoofer threads.

post-6832-0-08360000-1409581212_thumb.jp

Harman White Paper.pdf

Edited by DizRotus

Share this post


Link to post
Share on other sites
Multiple sub placement has probably already been addressed in other subwoofer threads.

 

 

I highly recommend the newest Beta version of REW. It has a room simulator that does a pretty good job of prediction on sub placement. It's the last button on the top right. See my Super Heresy mod thread for a pix.

Edited by ClaudeJ1

Share this post


Link to post
Share on other sites

For best distribution, you would be better off moving the couch forward as much as you can, and putting one in the center of each wall. You head position will be as critical as the woofer location, if not more.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Sign in to follow this  

×
×
  • Create New...