Legis' Horny Tales - diyAudio
Go Back   Home > Forums > Loudspeakers > Multi-Way
Home Forums Rules Articles diyAudio Store Gallery Wiki Blogs Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Multi-Way Conventional loudspeakers with crossovers

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 24th July 2015, 08:36 AM   #1
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
Default Legis' Horny Tales

I have been playing with the idea of making lower tuned tapped family members for my 4-way synergy horn system for quite some time. They will add the bottom octave to the system's repertoire. The TH's that are visible in the picture are tuned to ~32-33Hz and they do not go that low to give the "air vibration" effects near 20Hz, that only very low THD bass systems, that go low enough, can create. The new horn family members will take over where the higher tuned TH's start to roll off.

Given I had already these 4x18" BMS woofers and was at least subconsciously limited to the following size, here's what I came up with. After many hours of trying to squeeze a 10-13Hz horn/TQWT etc. into the same "small" size while keeping good efficiency, I gave up and returned to the original path, ie. maximize the efficiency and settle for adequate extension of ~16Hz that does not have air turbulence and other problems.

Tapped TL seemes to work very well with the BMS woofers and TL's notch after the pass band is good for me since I want to maximize the acoustic low pass. The woofer configuration will be push-pull.

Click the image to open in full size.

Click the image to open in full size.

16Hz tapped transmission line (T-TL) vs. 750 litre sealed box with same woofers. Two of these things corner/boundary loaded are ought to make some kind of noise.

Click the image to open in full size.

SPL vs. frequency at 1000w/10mm limit (in comparison to 750l sealed again):

Click the image to open in full size.


One fold scheme. The picture does not show bracing etc...

Click the image to open in full size.

Today is the day I will go and get the wood and start building these things. Some pictures are bound to follow at some point, I keep you posted.

Last edited by Legis; 24th July 2015 at 08:45 AM.
  Reply With Quote
Old 24th July 2015, 12:50 PM   #2
xrk971 is offline xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Looks like fun and way over the top as your projects usually are. You will paint it Ferrari red as well?

Will be following this. Good luck !
  Reply With Quote
Old 24th July 2015, 01:00 PM   #3
diyAudio Member
 
manninen's Avatar
 
Join Date: Jul 2014
yeah! red pianolacquer inside to better airflow
  Reply With Quote
Old 24th July 2015, 01:45 PM   #4
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
Quote:
Originally Posted by xrk971 View Post
Looks like fun and way over the top as your projects usually are. You will paint it Ferrari red as well?

Will be following this. Good luck !
Thanks X! I have not decided on the color yet, propably not fully red though. Maybe white with some red/black/?? details. I'll also have to see how the baltic birch plywood looks like when they are ready, staining could also be an option. The plywood is 21mm "Class B" baltic birch (some surface damages), but looked to be quite OK quality.
  Reply With Quote
Old 25th July 2015, 09:13 PM   #5
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
The area where the woofers come is quite hard to brace because big unbraced area is left behind the woofers. Maybe the magnet structure of the woofers can be somehow smartly coupled the panels to offer bracing.

Click the image to open in full size.
  Reply With Quote
Old 26th July 2015, 12:07 PM   #6
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
Bottom pieces are mostly "done", next the upper pieces.

Click the image to open in full size.

Also found a commercial product that looks very much like similar "tapped TL" design. The price tag is quite hefty.

http://www.wisdomaudio.com/pdfs/RTL.pdf
High performance in-wall and on-wall architectural products and subwoofers with Audyssey Room Correction - Wisdom Audio
  Reply With Quote
Old 27th July 2015, 08:15 PM   #7
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
Random progress pictures.

21mm thick 15-ply plywood close-up:

Click the image to open in full size.

Upper modules:

Click the image to open in full size.

Threaded inserts for attaching the side panels:

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.
  Reply With Quote
Old 27th July 2015, 08:25 PM   #8
xrk971 is offline xrk971  United States
diyAudio Member
 
xrk971's Avatar
 
Join Date: Oct 2012
Location: Metro DC area
Nice progress! You have pillow covers on the foam blocks at the mouth of the TH's - nice touch. I see you have acoustical treatments on wall - is that new?

I have to ask what those 6 long aluminum tubes are? 1/4-wave Helmholtz stub mid-bass traps? Do they have a measurable effect?

I see you are doing woodwork in your super clean listening room. Where is the sawdust?
  Reply With Quote
Old 27th July 2015, 08:52 PM   #9
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
Quote:
Originally Posted by xrk971 View Post
Nice progress! You have pillow covers on the foam blocks at the mouth of the TH's - nice touch. I see you have acoustical treatments on wall - is that new?

I have to ask what those 6 long aluminum tubes are? 1/4-wave Helmholtz stub mid-bass traps? Do they have a measurable effect?

I see you are doing woodwork in your super clean listening room. Where is the sawdust?
Yes, I also think that cloth on the foam blocks was a nice addition visually . I will also dampen the new TH's mouths the same way.

We have moved to a new apartment a month ago. The new room was pretty ugly acoustically, so I had to give it a little treatment. Acoutic panels (~8,5m2 total area) on the walls and white "tube bass traps" to the corners and other strategic spots. I have 6 tubes tuned to ~40hz and 6 tubes tuned to ~160Hz, together they cover the modal region 20-280Hz pretty well and kill the bass echoes quite good. Each tube trap in 80 litres, 120cm x 30cm dia, filled with rockwool, both ends sealed.

The aluminum pipes are Argent Room Lense imitations. Each pipe is open on both sides and each pipe in the groups of three have different amount of polyfill stuffing inside. I have got the impression this is how original Room Lenses are also done. Argent advertises they act as a wide band Helmholtz resonators but I have not measured any effects. I'ts propably quite small. I mainly use them as diffusers, to shatter some of the side wall's first reflection. They also make the stereo image somewhat more airy.

I do the more dust heavy work in a separate study room that I have temporarily emptied for this purpose. Some small drilling etc. goes well in the living room, like putting in the threaded inserts, nothing a quick vacuum cleaning cannot handle. But routing the woofer's holes was quite something inside the study room, without a breathing filter.

Last edited by Legis; 27th July 2015 at 08:56 PM.
  Reply With Quote
Old 29th July 2015, 08:38 PM   #10
Legis is offline Legis  Finland
diyAudio Member
 
Legis's Avatar
 
Join Date: Dec 2009
Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.

Click the image to open in full size.


Somewhat quick & dirty setup as I did not seal any non-permanent joints with a sealing gasget tape. Impedance plots show that the horns leak, which is not a suprise. Because of this the tuning of the horns are 20Hz and 21Hz, not 17,5Hz like simmed.

Click the image to open in full size.

Click the image to open in full size.

Simulated impedance:

Click the image to open in full size.

The response does not go as low as simmed, though my amp, uncalibrated mic, mic pre and dac might all have some attenuation at 20Hz also. I believe the leaking also decreases it somewhat because the tuning is higher.

Measured from the mouth while horn was not close any walls. Other plot is with the horn that has 2 x BMS 18s430v2 (better plot), and other that has 2 x BMS 18N850 woofers. (I have a 33Hz room mode which affects these measurements)

Click the image to open in full size.

2pi sim:

Click the image to open in full size.


How do they sound? FUNtastic ! Absolutely massive authority and utterly easy sounding. Very pure low notes and the low rumble. The sound signature is the same as with my other THs, in short it's precise but still mellow and has some quality to it which I would best describe as musical and natural. The two TH bands integrate semalessly together.

Last edited by Legis; 29th July 2015 at 08:42 PM.
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
SSLV1.1 builds & fairy tales Salas Power Supplies 3793 7th November 2016 09:57 PM
Any successful/unsuccessful tales of loading a large Coax in a front horn? POOH Multi-Way 35 22nd November 2015 09:58 PM
I got horny again... Death By Bass Subwoofers 26 20th August 2010 08:33 AM
I'm getting Horny! Arcdesigns Multi-Way 20 31st March 2003 05:16 AM


New To Site? Need Help?

All times are GMT. The time now is 07:48 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2016 DragonByte Technologies Ltd.
Copyright 1999-2016 diyAudio

Content Relevant URLs by vBSEO 3.3.2
Wiki