Dayton Classic 18" DCS-450 - Tapped Horn?

[zobsky]

Originally Posted by dolinux

I finally got my camera. Here are pics of the assembled box. Testing with a Dayton 240w plate amp. The the sound level and range is impressive. I used 2x2" bracing in the vertical corners, and to make assembly faster.

I also built a scaled down version for a $30 12" PE buyout sub that I picked up, which is also impressive. I may start a new 'budget T-TQWT' thread for that one, <$100 for everything but the amp.

Thanks again bjorno!

Cool. Impressive compared to what? i.e. have you tried the drivers in other designs?

What's the freq. response like? Do you get a clean 20 Hz indoors?

[freddi]

hi bjorno - how might you build a "modern" Karlson-style speaker using hornresp?

[kenpeter]

Well my K15 with undersized 12" hole and oversized SigmaPro18" hiding behind seems
quite similar to what I see in this sub's photo. Mine worked much better after I had
opened the hole to the full size. Mind you though, I was only choking the front side
of the driver, not the whole front of the inverted horn mouth.

[zobsky]

Originally Posted by kenpeter

Well my K15 with undersized 12" hole and oversized SigmaPro18" hiding behind seems
quite similar to what I see in this sub's photo. Mine worked much better after I had
opened the hole to the full size. Mind you though, I was only choking the front side
of the driver, not the whole front of the inverted horn mouth.

Not quite. Your K15/18/12 had hardly any clearance between the baffle and the driver (more similar to the gawd awful ripole sub i built two weeks ago), whereas in this case, the opening is part of the horn terminus. In this case, if I remember the theory, the terminus openingcross sectional area = hornresp specified Sx (x = last segment), ... and the negative taper is necessary to achieve a lower freq. response.

[kenpeter]

Your ripole had completely different issues. I don't see any similarity.
Mine was choked in the focus of the cone, yours off to one side...

The acoustic short circuit around K15 shelf might be of about the
same as a ripole, but a huge difference how extra air gets swept
up in tapped horn and K effect and added to the wavefront that
radiates into the room.

[freddi]

what I'd like to know is what easy mod might be done to the simple one-fold inverse or positive taper tapped horn/pipe to mitigate their typical suckout

7.4 cubic foot inverse tapered pipe with 15" Dayton 295070 speaker vs 7.7 cubic foot K15 with Audio Nirvana Super10 - one trace has the mouth panel removed giving an opening larger than Sd - tuning and cutoff are a bit higher - for an experiment a Karlson slot might be used.

Input impedance with 295070

to keep a pipe looking like a Karlson, and give it a positive flare with somewhat higher cutoff in a given bulk perhaps "this"