HLCM - Horn loaded compact monitor

POOH

Member
2010-10-05 9:06 pm
Ohio
In pursuit of pure playback realism and a system that has low compromise in in-the-room tone and presence I will document my mistakes here in this thread. The goal of the horn array is to have no hesitation in believe ability when listening to a good recording. I find from the upper bass up must be front horn loaded, otherwise it just sounds like a speaker trying to be real paddling away at the room air sounding fake. Horns move the air needed for the human to be fooled into experiencing realism. The system is made to fire down the long walls of my rectangular concrete bunker and sits on carpeted concrete slab. The system is made to work with the room.

Here is the in room response of the low midrange and upper bass (heart of the system), one channel 15' away at the listening position. Here is where most of the music lives and this compact horn system is built around this range first. This range consists of two parts, one the B&C 8pe21 in a 46" long front horn with an 8 square foot mouth and 4" throat 120 - 1K range @ 106 db/w/m sensitivity. Two, the horizontal floor coupled line array stands for the midrange horn with four sealed 8" woofers wired in parallel with 103 db w/m voltage sensitivity. These two parts are biamped and the upper bass coupling stands operate 60 to 120 cycles and can be precisely aligned with the 8pe21. If you get this range right you will have a basis for a system with realistic in room sound. The bass modules are high passed 4th order at 60 cycles and operate in stereo. The midrange horns can operate up to 800 cycles realistically.

hornbassmodule.jpg
 

POOH

Member
2010-10-05 9:06 pm
Ohio
I'll take some pictures soon, it's really compact for front horn system down to 100 Hz. I've managed to reduce the weight of the bass horns to under 100 lbs each. No not direct radiator monitor size but those tend to sound fake and compressed. The midbass horns are fiberglass and I damped them with 4" of compressed memory foam. That stuff gets pretty heavy and really knocked down the noise.
 
Last edited:

CLS

Member
2005-06-17 6:58 am
Taiwan
....

I find from the upper bass up must be front horn loaded, otherwise it just sounds like a speaker trying to be real paddling away at the room air sounding fake. Horns move the air needed for the human to be fooled into experiencing realism. ....

Hi POOH,

Good work! As always.

Regarding the midbass range, I remember you once mentioned that the best midbass punch you got was from a pair of Karlson Klam. (that's a very special thing to me at that time, so it's a deeply pressed impression)

So, as time goes by, you came 'back' to horn anyway. Mind to compare them? :)
 

POOH

Member
2010-10-05 9:06 pm
Ohio
Hi POOH,

Good work! As always.

Regarding the midbass range, I remember you once mentioned that the best midbass punch you got was from a pair of Karlson Klam. (that's a very special thing to me at that time, so it's a deeply pressed impression)

So, as time goes by, you came 'back' to horn anyway. Mind to compare them? :)

The Klam in it's range and for it's size is still the slam master of all I've had. Good down to 50-60 cycles and punch that's really close to what I have now. For the size and up to around 200 they will always have a place in my heart. LOL- I actually had one "Rosie" cabinet loaded with an Altec 15 in the room a couple of weeks ago trying to figure out how I could fit them in the room to run below the big mid horns. They are just too big... but I'm working on it :)
 

POOH

Member
2010-10-05 9:06 pm
Ohio
What kind of room do you have? What will be used in the high range?

That kind of setup needs a quite long listening distance to generate a homogenous sound, I assume you'll need a listening distance of at least 4-5m.

Hello, I have a concrete bunker around 14.5' wide by 24 deep its on a slab with concrete block walls (an addition below a room built for my wife)

High range is still debatable but most likely settling on the Community M200 for the upper midrange low treble and the celestion CDX1730 for the upper treble. The bass right now is five JBL 2242H 18's (one in mono horn loaded) and a rear dual 18 with two Dayton 18" sub drivers . What I am working on is some additional bass couplers (they are done and in the system) that also work as stands for the throat/compression chamber of the upper bass/mid horn. The stands have four 8" drivers in a horizontal line sealed coupled to the floor. I'm not 100 percent sold on it yet - the JBL 18's do pretty good on their own. But I want to move the array closer to me (currently 15 feet) so I was thinking I'd want the bass closer to horns - really what I need to do is move the big stereo 18 cabinets closer a nd sacrifice a littl on the bottom octave (I have lots to spare) - The cabinets weigh around 300 pounds a piece so i am waiting for my son to have some time to help move them around.
 
Hello, I have a concrete bunker around 14.5' wide by 24 deep its on a slab with concrete block walls (an addition below a room built for my wife)
Does that concrete bunker type room has anything to do with being below her room and ..uhm.. her weight? :D j/k

The room should be big enough for a homogene sound.

High range is still debatable but most likely settling on the Community M200 for the upper midrange low treble and the celestion CDX1730 for the upper treble.

The CDX 1730 are a good choice, I find the CDX1-1430 a bit more detailed at the high end though. I guess that's the different diaphragm material and lighter mass. The 1730 is still a good choice, they sound great too.
 

POOH

Member
2010-10-05 9:06 pm
Ohio
Does that concrete bunker type room has anything to do with being below her room and ..uhm.. her weight? :D j/k

The room should be big enough for a homogene sound.



The CDX 1730 are a good choice, I find the CDX1-1430 a bit more detailed at the high end though. I guess that's the different diaphragm material and lighter mass. The 1730 is still a good choice, they sound great too.

- There is an 8 person hot tub in the the room directly above where my speakers sit, it's a pretty heavy duty foundation

I have the 1425 and it is a little more detailed too but I still prefer the 1730 in the 2-8K range - I have a pair of these on the way see if I can improve with a "planar horn" - sensitivity is claimed at 105db

Dayton Audio PHT1-6 Planar Horn Tweeter 6 Ohm

http://www.daytonaudio.com/media/resources/data-files/PHT1-6_data.zip
 
Last edited:

POOH

Member
2010-10-05 9:06 pm
Ohio
well, I'll be more interested if and when I see pix of what it is replacing, and/or what it is... but you do have a sense of humor... :D

The picture of the midbass horns= in my moniker is about 800 lbs (pair) of it. The midbass horns I retired were filled with sand and bricks, also retired is two front loaded corner horns (twin 15's- 14' path) and pair of line arrays of four 15" - triple wall front baffles and double wall every where else. It was stupid insane
 
- There is an 8 person hot tub in the the room directly above where my speakers sit, it's a pretty heavy duty foundation

I wasn just kidding. :D It's a very nice (and suitable!) listening room. I hate it when a door or window or cupboard starts to rattle. My last appartment was even worse, the ceiling made noise too and unlike the doors or boards you unfortunately can't fix that easily.

I have the 1425 and it is a little more detailed too but I still prefer the 1730 in the 2-8K range - I have a pair of these on the way see if I can improve with a "planar horn" - sensitivity is claimed at 105db

Dayton Audio PHT1-6 Planar Horn Tweeter 6 Ohm

It always comes down to what one prefers and the 1730 are a good choice. The PHT1-6 are good tweeters, very good resolution, but they can't keep the 105dB in the upper treble. It drops 5dB at 15k on axis and 15dB (!!) at 30°, which leaves you only 90dB 30° off axis. I don't know what dispersion angle you are aiming for or if it will be a passive or active setup.
 

POOH

Member
2010-10-05 9:06 pm
Ohio
It always comes down to what one prefers and the 1730 are a good choice. The PHT1-6 are good tweeters, very good resolution, but they can't keep the 105dB in the upper treble. It drops 5dB at 15k on axis and 15dB (!!) at 30°, which leaves you only 90dB 30° off axis. I don't know what dispersion angle you are aiming for or if it will be a passive or active setup.

Years ago I had a friend (You out there Bob? lol) that was really into organ music and he'd hop over here and bring his records and CD's and a bottle of Captain Morgan's rum and I'd let him take over the system and set the controls for the sun. :) One night, must have been 2 am, my wife was traveling and he decided to put on some Telarc Bach Michael Murray - when the bottom stop came on we were just sitting there fluttering and all of a sudden smoke came pouring out the wall beside us. It was the mortar between the blocks.. it lasted about 5 seconds or so before we figured out what it was ( the Captain was gone) - my buddy the brick layer came over to see what we had done scratched his beard and just shook his head. :eek: That was when I had three of the Sensurround subs in the room.

I like a tight 40-60 degree horizontal dispersion and want real tight vertical - Most compression drivers I like don't do much more than 12-14k with out dropping down upper treble. I'm going to see what I think of them when they get here

admhrn.jpg
 
Last edited:

freddi

Member
Paid Member
2005-08-16 4:21 pm
so that's what the C-V sub looked like inside. For a "micro" system, I think a K-coupler with strong and light 18 or maybe 4-10" or 12" per cabinet to reduce thermal compression might get some things right for midbass in a compact for no deeper than 18 inches. - it would take some real input power for >120dB peaks so little SE tube amps are out to get reasonable dynamics. Then tapped horn or pipe for low bass.