15" tapped horn with RCF

Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.
Hi all!
I'm sharing here with you my tapped horn i’ve recently finished.

First of all, thats not a th-115 copy.

It may look like the th-115, but i have never seen one in real yet, i dont know how it looks inside. All the calculations and woodwork are made by myself.

My goal was to build something goes down to 40 hz, and has more than 100 db/w/m sensitivity. I played around with hornresp and decided to use the RCF LF15 G401 in a 40 hz tapped horn.

An externally hosted image should be here but it was not working when we last tested it.


An externally hosted image should be here but it was not working when we last tested it.


Excursion powered with 800W
An externally hosted image should be here but it was not working when we last tested it.


Than i designed a cab for it:
An externally hosted image should be here but it was not working when we last tested it.


..and started making sawdust:
An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.

An externally hosted image should be here but it was not working when we last tested it.


done...
An externally hosted image should be here but it was not working when we last tested it.


And here are the measurings i did outside with 2,83 V from 1m distance.

The unprocessed response:
An externally hosted image should be here but it was not working when we last tested it.


..and processed with a DSP:
HPF: 30 hz, 48db/o (for the speaker protection)
LPF: 200 hz, 48db/o
EQ: 200hz, -4db, Q1
An externally hosted image should be here but it was not working when we last tested it.


My goal has been achieved :)

We had the first "test" last weekend, a little electronic music party with 40-50 people in a middle sized room, and the result was astonishing. Incredibly deep bass, very loud and clean. It was driven by the T-AMP TA2400. I couldn't even drove it hard, bcause the whole building started falling apart. :)

(ps.: sorry for my poor english)
 
THX :)

What is the black finish? Truck bed liner? It looks good for this sort of use.

No... It is the Warnex textured lacquer... like this.

An externally hosted image should be here but it was not working when we last tested it.


Its very hard, u cant sctratch it, is waterproof and it still looks good ... I think this is the best choice for PA boxes.
 
Last edited:
Compliments on a sucessful project.:cool:
I would very much like to see your input parameters for Hornresp.
Also I an very interested in the parallel horn section that is adjacent to the driver. I like how with that extra folded section you have managed to increase the length of the horn and not waste any internal space.
 
Made two TH using the same driver. Worked out really well.

I have never run more than 400W peak RMS through it (limited with DCX2496) bumped it down to 200W as I really didn't need every light and ventilation to vibrate.

Mine where slightly higher tuned but are 233L external volume. 102-103dB 2,83V (around 1W) IIRC.

So I can imagine what yous can do.
 
Made two TH using the same driver. Worked out really well.

I have never run more than 400W peak RMS through it (limited with DCX2496) bumped it down to 200W as I really didn't need every light and ventilation to vibrate.

Mine where slightly higher tuned but are 233L external volume. 102-103dB 2,83V (around 1W) IIRC.

So I can imagine what yous can do.

At 400W the RCF driver would be fine.

If you follow the usual recommendation (for PA) of an amp with a power output of double the continuous driver rating (to allow for music crest factors) the BMS15N850 is the only 15" driver I've found that can handle anywhere near this without running out of Xmax (16mm using the usual formula).

Ian
 
I dont think this RCF reaches the Xmax limit, even if i drive it with 800 W. Note, that u are playing music, not sinewaves what the hornresp predicts.

For example: The hornresp Displacement graph says, that the excursion of the LF15G401 is 13,2 mm if the total 800W RMS(!) is on a 50 Hz sinewave.. Thats never gonna happen.

Danley is using in a 40Hz TH the B&C 15 TBX 100 which has an xmax value of 9mm, and 1000W power.
 
I dont think this RCF reaches the Xmax limit, even if i drive it with 800 W. Note, that u are playing music, not sinewaves what the hornresp predicts.

For example: The hornresp Displacement graph says, that the excursion of the LF15G401 is 13,2 mm if the total 800W RMS(!) is on a 50 Hz sinewave.. Thats never gonna happen.

Danley is using in a 40Hz TH the B&C 15 TBX 100 which has an xmax value of 9mm, and 1000W power.

Indeed he is -- whether this is an issue or not depends very much on the type of music you're playing and how big the amp is, instruments like bass guitar or kick drum probably won't have a problem, synth bass on dubstep (not that I play this but some people do :) probably will.

Since one of the tapped horn advantages is low distortion, it seems a shame to run the risk of adding distortion back again by running out of Xmax -- which is what will happen with the RCF if you do hit it with 800W sinewave at 40Hz, that's why it won't reach 13mm.

Given that they're available, I'd pick a driver with more Xmax -- *if* I was going to drive it heavily -- to make sure this didn't happen. If you're not doing this and don't play music where the bass resembles swept sinewaves then the RCF driver will be fine with 800W, as is the B&C with 1000W (or more on most music).

And as I said, more Xmax usually means more money...

Ian

P.S. The driver in the TH118 has >2x the volume displacement of the 15TBX100 as well as more power handling, so this is less of an issue.
 
YES!

(And) Anyone care to try getting this type of response, but tuned to 30 or 35Hz? (electronic music i.e. dubstep/d&b)

FYI, TH tuned at 37 Hz:

b:magnify:
 

Attachments

  • RFC-LF15G401_368L_TH.JPG
    RFC-LF15G401_368L_TH.JPG
    334.2 KB · Views: 1,691
Last edited:
Last edited:
Status
This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.