Multicell Horn Speakers

russtafarian

Well-Known Member
Jul 12, 2012
25
44
318
Greetings!

I’m not sure what to call a speaker that looks like a character straight out of The Nightmare Before Christmas (1993) - IMDb.

Horns Side.JPG

My name is Russ and I’m new to WBF thanks to meeting and striking up a friendship with Ron Resnick a few months back. Ron is a pretty convincing WBF evangelist, and he encouraged me to share these speakers with the WBF crowd. My background is in both hi-fi and pro audio. I’ve mixed live music for over 30 years. The sonic character of big woofers and horn-loaded compression drivers is burned into my lizard brain. The first great playback system I heard was in the recording studio at Golden West College where I studied audio engineering. The studio control room had Urei 813 studio monitors driven by Crown amps. I’ve been chasing that sound ever since.

To my ear, most hi-fi speakers sound small, constricted, and overly bright compared to properly tuned, high efficiency studio monitors. I haven’t had a typical hi-fi speaker in my home system since the mid ‘90s (PSB Stratus Silver). Since then I’ve owned Gallo Nucleus Ref 2 (never should have sold them), VMPS RM30, Zu Soul, Tekton Double Impact, and most recently, Duke Lejeune’s original Jazz Module. I love the Jazz Modules and will hang on to them for when I want to put a system in a smaller space.


Horns Pair.JPG


This speaker represents a current technology implementation of an old-school design. The core parameters were established in the mid-‘30s by the Shearer Horn Project. SHEARER HORN (audioheritage.org) The Shearer Horn was developed by engineers from MGM, RCA, Lansing Manufacturing, and Western Electric to provide dynamic, articulate sound for movie theaters. John Hilliard’s white paper, published in 1936, established the following parameters:
  • Frequency response of +/- 2 dB from 50 to 8,000 Hz within 3 meters of the mouth of the horn
  • Volume (dynamic) range of 60 dB
  • Phase delay of less than 1 ms between drivers to create a point source
  • Angular distribution of 110 degrees horizontal and 60 degrees vertical with a uniform response at all positions
The engineering parameters of the Shearer Horn still hold up today. At the time, movie playback systems were intentionally limited to 8 kHz because “above 8000 Hz noise, flutter, and harmonics due to recording deficiencies become decidedly the limiting factor.” The need for higher bandwidth speakers came later with the post-war implementation of magnetic tape recorders and LP records for music recording and playback.


Horns Bass.JPG


My friend Justin Weber is the visionary behind these speakers. Justin designs and builds tube amplifiers for his ampsandsound brand. He builds speakers for fun. Last fall Justin told me about his multicell horn project. He set out to build a speaker that marries the magic of multicell horns to proven bass bin and crossover designs and reliable, great-sounding drivers. Justin’s a dreamer. He loves building big speakers that push the boundaries. When he told me he was selling the multicell horns because he needed the space for his next project, I snapped them up. I heard enough of that multicell magic at his place to hook me, and I knew I had the room and the gear to make them work. By the way, Justin will be at THE Show this weekend, June 10-12, Long Beach, CA. His power amps will be in the Acora Acoustics room and he will be demonstrating headphone amps in the Headphonium.


Horns Closeup.JPG


Each speaker channel consists of:

Horns Crossover.JPG

My additions to the speaker:
  • Behringer CX2310 analog electronic crossover for the bass horns and subwoofers only. Behringer | Product | CX2310
  • B&K ST1400 II solid-state amp to direct drive the bass horns.
  • Two sealed down-firing 15” subwoofers powered by a cheap-ass pro sound amp.
The rest of the system:
  • Almarro A205A II, EL84 SEP, 5 wpc
  • EAR 868 phono pre/line stage
  • Denon DP80 direct-drive turntable in a custom plinth by ampsandsound
  • Jelco TK950L tonearm with Ortofon SPU Classic E or Denon/Zu DL103 cartridges
  • Denon TA-401 tonearm with Shure M95ED, Grado MCZ, or Ortofon 2M Mono cartridges
  • Digital stuff blah, blah, blah

Horns Back.JPG

Getting the horns integrated into my system has been a process. After six weeks I feel like I’m about 35% there. The first challenge was managing the system’s gain to minimize noise and optimize volume control range. The speakers are so efficient that the initial usable volume range on the preamp was between 7 and 9 o’clock; way too low. After futzing around with various adjustments, I ended up building and inserting -15 dB resistor pads between the preamp and amp. The usable volume range is now between 9 and 12 o’clock.

The ongoing challenge, as with any speaker, has been to get them tuned to the room. To establish a reference point for the speaker's balance, I compare what I'm hearing in the room to the same source material played through level-matched Audeze LCD-X headphones or Noble Kaiser 10 IEMs. The multicell horns effectively take out the room within their bandwidth of 500 Hz and up. I sit 13 feet away from the speakers and get near-field presentation. It's the transition from the big multicell horn to the bass bin that gets challenging. The crossover frequency sits at the lower end of the vocal range. Using an electronic crossover on the bass bins allows me to tune the transition by ear. Drop the filter frequency too low and voices sound thin and telephonic. Push it too high and voices get bloated and muffled. The sweet spot is not hard to find. The crossover is within reach of the listening seat so if I want to, I can tweak it to get the right blend for each record.

I think that's enough for now.

Russ

Horns Single.JPG
 
Last edited by a moderator:

PeterA

Well-Known Member
Dec 7, 2011
10,272
7,731
1,565
North Shore of Boston
Hello Russ,

What a very interesting system. Welcome to WBF and thank you for sharing your speakers and the rest of the system with us. The turntable is gorgeous and I recognized it as a denon from the photograph. What do you think the efficiency is of your speakers and are the downfiring 15 inch woofers at the bottom of that cabinet? I don’t quite understand where those big subwoofer drivers are.
 

Ron Resnick

Site Co-Owner, Administrator
Jan 25, 2015
11,356
6,641
1,365
Beverly Hills, CA
Thank you, Russ, for this wonderful and detailed introduction to you and to your system and to your great new two-of-a-kind loudspeakers! Welcome to WBF!
 
Last edited:
  • Like
Reactions: russtafarian

Ron Resnick

Site Co-Owner, Administrator
Jan 25, 2015
11,356
6,641
1,365
Beverly Hills, CA
Russ is totally into vinyl and tubes, no digital anywhere, so we hit it off right away when Danny Kaey introduced us several months ago at his going away party.

I heard Russ' new loudspeakers a couple of weeks ago. During a prior visit I enjoyed Duke's Jazz Module loudspeakers in Russ' system -- I think Duke did a wonderful job with that speaker using those now-extinct drivers. I totally understand why Russ is keeping those speakers.

But the new horn-based speakers are in a different league sonically, I think. The presentation of the new speakers is much wider and more open. I think the multi-cell horn really is a great way to transmit sound into a room.

Two 12 inch drivers in each speaker and the subwoofers provide plenty of low-frequency foundation to the music.

Russ' turntable, as Peter sees correctly, is gorgeous!

Russ' subwoofers are cleverly concealed as end tables on each side of Russ' couch. Russ has a very flexible pro-audio crossover that he can use to adjust the low pass slope and the drive of the subwoofers.
 
Last edited:

russtafarian

Well-Known Member
Jul 12, 2012
25
44
318
Hello Russ,

What a very interesting system. Welcome to WBF and thank you for sharing your speakers and the rest of the system with us. The turntable is gorgeous and I recognized it as a denon from the photograph. What do you think the efficiency is of your speakers and are the downfiring 15 inch woofers at the bottom of that cabinet? I don’t quite understand where those big subwoofer drivers are.
Hi Peter,

I had better resolve this mystery. My two subwoofers aren’t pictured since they sit on either side of my listening couch. Each “end table” is a sealed, reinforced cabinet with a down-firing, high x-max 15 inch driver.


B48C63A9-8E77-4717-AEB2-6FC853EE66EA.jpeg

In the photo you can see one of the sub cabinets holding up a VPI record cleaner and a few headphones. In the mini rack is the electronic crossover that controls the subs and bass bins. Below the crossover is a Mackie headphone amp.
 

bonzo75

Member Sponsor
Feb 26, 2014
18,869
8,997
1,515
London
Greetings!

I’m not sure what to call a speaker that looks like a character straight out of The Nightmare Before Christmas (1993) - IMDb.

View attachment 94338

My name is Russ and I’m new to WBF thanks to meeting and striking up a friendship with Ron Resnick a few months back. Ron is a pretty convincing WBF evangelist, and he encouraged me to share these speakers with the WBF crowd. My background is in both hi-fi and pro audio. I’ve mixed live music for over 30 years. The sonic character of big woofers and horn-loaded compression drivers is burned into my lizard brain. The first great playback system I heard was in the recording studio at Golden West College where I studied audio engineering. The studio control room had Urei 813 studio monitors driven by Crown amps. I’ve been chasing that sound ever since.

To my ear, most hi-fi speakers sound small, constricted, and overly bright compared to properly tuned, high efficiency studio monitors. I haven’t had a typical hi-fi speaker in my home system since the mid ‘90s (PSB Stratus Silver). Since then I’ve owned Gallo Nucleus Ref 2 (never should have sold them), VMPS RM30, Zu Soul, Tekton Double Impact, and most recently, Duke Lejeune’s original Jazz Module. I love the Jazz Modules and will hang on to them for when I want to put a system in a smaller space.


View attachment 94337


This speaker represents a current technology implementation of an old-school design. The core parameters were established in the mid-‘30s by the Shearer Horn Project. SHEARER HORN (audioheritage.org) The Shearer Horn was developed by engineers from MGM, RCA, Lansing Manufacturing, and Western Electric to provide dynamic, articulate sound for movie theaters. John Hilliard’s white paper, published in 1936, established the following parameters:
  • Frequency response of +/- 2 dB from 50 to 8,000 Hz within 3 meters of the mouth of the horn
  • Volume (dynamic) range of 60 dB
  • Phase delay of less than 1 ms between drivers to create a point source
  • Angular distribution of 110 degrees horizontal and 60 degrees vertical with a uniform response at all positions
The engineering parameters of the Shearer Horn still hold up today. At the time, movie playback systems were intentionally limited to 8 kHz because “above 8000 Hz noise, flutter, and harmonics due to recording deficiencies become decidedly the limiting factor.” The need for higher bandwidth speakers came later with the post-war implementation of magnetic tape recorders and LP records for music recording and playback.


View attachment 94334


My friend Justin Weber is the visionary behind these speakers. Justin designs and builds tube amplifiers for his ampsandsound brand. He builds speakers for fun. Last fall Justin told me about his multicell horn project. He set out to build a speaker that marries the magic of multicell horns to proven bass bin and crossover designs and reliable, great-sounding drivers. Justin’s a dreamer. He loves building big speakers that push the boundaries. When he told me he was selling the multicell horns because he needed the space for his next project, I snapped them up. I heard enough of that multicell magic at his place to hook me, and I knew I had the room and the gear to make them work. By the way, Justin will be at THE Show this weekend, June 10-12, Long Beach, CA. His power amps will be in the Acora Acoustics room and he will be demonstrating headphone amps in the Headphonium.


View attachment 94335


Each speaker channel consists of:

View attachment 94336

My additions to the speaker:
  • Behringer CX2310 analog electronic crossover for the bass horns and subwoofers only. Behringer | Product | CX2310
  • B&K ST1400 II solid-state amp to direct drive the bass horns.
  • Two sealed down-firing 15” subwoofers powered by a cheap-ass pro sound amp.
The rest of the system:
  • Almarro A205A II, EL84 SEP, 5 wpc
  • EAR 868 phono pre/line stage
  • Denon DP80 direct-drive turntable in a custom plinth by ampsandsound
  • Jelco TK950L tonearm with Ortofon SPU Classic E or Denon/Zu DL103 cartridges
  • Denon TA-401 tonearm with Shure M95ED, Grado MCZ, or Ortofon 2M Mono cartridges
  • Digital stuff blah, blah, blah

View attachment 94333

Getting the horns integrated into my system has been a process. After six weeks I feel like I’m about 35% there. The first challenge was managing the system’s gain to minimize noise and optimize volume control range. The speakers are so efficient that the initial usable volume range on the preamp was between 7 and 9 o’clock; way too low. After futzing around with various adjustments, I ended up building and inserting -15 dB resistor pads between the preamp and amp. The usable volume range is now between 9 and 12 o’clock.

The ongoing challenge, as with any speaker, has been to get them tuned to the room. To establish a reference point for the speaker's balance, I compare what I'm hearing in the room to the same source material played through level-matched Audeze LCD-X headphones or Noble Kaiser 10 IEMs. The multicell horns effectively take out the room within their bandwidth of 500 Hz and up. I sit 13 feet away from the speakers and get near-field presentation. It's the transition from the big multicell horn to the bass bin that gets challenging. The crossover frequency sits at the lower end of the vocal range. Using an electronic crossover on the bass bins allows me to tune the transition by ear. Drop the filter frequency too low and voices sound thin and telephonic. Push it too high and voices get bloated and muffled. The sweet spot is not hard to find. The crossover is within reach of the listening seat so if I want to, I can tweak it to get the right blend for each record.

I think that's enough for now.

Russ

View attachment 94339

Hi Russ, welcome and looks very nice.

So to summarize this is a dual woofer FLH similar to Altec 817, using Markus Klug's Altec replica multicell, eminent delta woofers and Radian above 500 Hz. Plus subs. Electronic crossover
 
Last edited:
  • Like
Reactions: russtafarian

russtafarian

Well-Known Member
Jul 12, 2012
25
44
318
Hello Russ,

What a very interesting system. Welcome to WBF and thank you for sharing your speakers and the rest of the system with us. The turntable is gorgeous and I recognized it as a denon from the photograph. What do you think the efficiency is of your speakers and are the downfiring 15 inch woofers at the bottom of that cabinet? I don’t quite understand where those big subwoofer drivers are.

Speaker efficiency is determined by the least sensitive driver(s) in the system. In this case it’s the woofers. Each 12” woofer is rated at 94 dB. Doubling the woofers and adding a few dB of horn gain puts the bass bin sensitivity at around 100 dB. The compression drivers are rated at 110 dB so they are attenuated in the crossover to match the output of the bass bin.

Here are a few turntable photos. The plinth was designed and built for me by Justin Weber.


9EBFD694-E175-4C27-B5E7-3030A373E13D.jpeg 278641CC-4A48-438E-8496-B1DAF95761B2.jpeg
 

russtafarian

Well-Known Member
Jul 12, 2012
25
44
318
Russ is totally into vinyl and tubes, no digital anywhere, so we hit it off right away when Danny Kaey introduced us several months ago at his going away party.

I heard Russ' new loudspeakers a couple of weeks ago. During a prior visit I enjoyed Duke's Jazz Module loudspeakers in Russ' system -- I think Duke did a wonderful job with that speaker using those now-extinct drivers. I totally understand why Russ is keeping those speakers.

But the new horn-based speakers are in a different league sonically, I think. The presentation of the new speakers is much wider and more open. I think the multi-cell horn really is a great way to transmit sound into a room.

Two 12 inch drivers in each speaker and the subwoofers provide plenty of low-frequency foundation to the music.

Russ' turntable, as Peter sees correctly, is gorgeous!

Russ' subwoofers are cleverly concealed as end tables on each side of Russ' couch. Russ has a very flexible pro-audio crossover that he can use to adjust the low pass slope and the drive of the subwoofers.
Ron,

Excellent job describing the sound of the speakers. Now I don’t have to.
 

morricab

Well-Known Member
Apr 25, 2014
7,182
3,126
653
Switzerland
Greetings!

I’m not sure what to call a speaker that looks like a character straight out of The Nightmare Before Christmas (1993) - IMDb.

View attachment 94338

My name is Russ and I’m new to WBF thanks to meeting and striking up a friendship with Ron Resnick a few months back. Ron is a pretty convincing WBF evangelist, and he encouraged me to share these speakers with the WBF crowd. My background is in both hi-fi and pro audio. I’ve mixed live music for over 30 years. The sonic character of big woofers and horn-loaded compression drivers is burned into my lizard brain. The first great playback system I heard was in the recording studio at Golden West College where I studied audio engineering. The studio control room had Urei 813 studio monitors driven by Crown amps. I’ve been chasing that sound ever since.

To my ear, most hi-fi speakers sound small, constricted, and overly bright compared to properly tuned, high efficiency studio monitors. I haven’t had a typical hi-fi speaker in my home system since the mid ‘90s (PSB Stratus Silver). Since then I’ve owned Gallo Nucleus Ref 2 (never should have sold them), VMPS RM30, Zu Soul, Tekton Double Impact, and most recently, Duke Lejeune’s original Jazz Module. I love the Jazz Modules and will hang on to them for when I want to put a system in a smaller space.


View attachment 94337


This speaker represents a current technology implementation of an old-school design. The core parameters were established in the mid-‘30s by the Shearer Horn Project. SHEARER HORN (audioheritage.org) The Shearer Horn was developed by engineers from MGM, RCA, Lansing Manufacturing, and Western Electric to provide dynamic, articulate sound for movie theaters. John Hilliard’s white paper, published in 1936, established the following parameters:
  • Frequency response of +/- 2 dB from 50 to 8,000 Hz within 3 meters of the mouth of the horn
  • Volume (dynamic) range of 60 dB
  • Phase delay of less than 1 ms between drivers to create a point source
  • Angular distribution of 110 degrees horizontal and 60 degrees vertical with a uniform response at all positions
The engineering parameters of the Shearer Horn still hold up today. At the time, movie playback systems were intentionally limited to 8 kHz because “above 8000 Hz noise, flutter, and harmonics due to recording deficiencies become decidedly the limiting factor.” The need for higher bandwidth speakers came later with the post-war implementation of magnetic tape recorders and LP records for music recording and playback.


View attachment 94334


My friend Justin Weber is the visionary behind these speakers. Justin designs and builds tube amplifiers for his ampsandsound brand. He builds speakers for fun. Last fall Justin told me about his multicell horn project. He set out to build a speaker that marries the magic of multicell horns to proven bass bin and crossover designs and reliable, great-sounding drivers. Justin’s a dreamer. He loves building big speakers that push the boundaries. When he told me he was selling the multicell horns because he needed the space for his next project, I snapped them up. I heard enough of that multicell magic at his place to hook me, and I knew I had the room and the gear to make them work. By the way, Justin will be at THE Show this weekend, June 10-12, Long Beach, CA. His power amps will be in the Acora Acoustics room and he will be demonstrating headphone amps in the Headphonium.


View attachment 94335


Each speaker channel consists of:

View attachment 94336

My additions to the speaker:
  • Behringer CX2310 analog electronic crossover for the bass horns and subwoofers only. Behringer | Product | CX2310
  • B&K ST1400 II solid-state amp to direct drive the bass horns.
  • Two sealed down-firing 15” subwoofers powered by a cheap-ass pro sound amp.
The rest of the system:
  • Almarro A205A II, EL84 SEP, 5 wpc
  • EAR 868 phono pre/line stage
  • Denon DP80 direct-drive turntable in a custom plinth by ampsandsound
  • Jelco TK950L tonearm with Ortofon SPU Classic E or Denon/Zu DL103 cartridges
  • Denon TA-401 tonearm with Shure M95ED, Grado MCZ, or Ortofon 2M Mono cartridges
  • Digital stuff blah, blah, blah

View attachment 94333

Getting the horns integrated into my system has been a process. After six weeks I feel like I’m about 35% there. The first challenge was managing the system’s gain to minimize noise and optimize volume control range. The speakers are so efficient that the initial usable volume range on the preamp was between 7 and 9 o’clock; way too low. After futzing around with various adjustments, I ended up building and inserting -15 dB resistor pads between the preamp and amp. The usable volume range is now between 9 and 12 o’clock.

The ongoing challenge, as with any speaker, has been to get them tuned to the room. To establish a reference point for the speaker's balance, I compare what I'm hearing in the room to the same source material played through level-matched Audeze LCD-X headphones or Noble Kaiser 10 IEMs. The multicell horns effectively take out the room within their bandwidth of 500 Hz and up. I sit 13 feet away from the speakers and get near-field presentation. It's the transition from the big multicell horn to the bass bin that gets challenging. The crossover frequency sits at the lower end of the vocal range. Using an electronic crossover on the bass bins allows me to tune the transition by ear. Drop the filter frequency too low and voices sound thin and telephonic. Push it too high and voices get bloated and muffled. The sweet spot is not hard to find. The crossover is within reach of the listening seat so if I want to, I can tweak it to get the right blend for each record.

I think that's enough for now.

Russ

View attachment 94339
Aluminum or Be diaphragms? Nice system! Did you explore other driver options? Just curious how you settled on the Radians.
 

Audiophile Bill

Well-Known Member
Mar 23, 2015
4,320
4,033
675
Welcome to WBF - very good to have you join our community.
 
  • Like
Reactions: russtafarian

russtafarian

Well-Known Member
Jul 12, 2012
25
44
318
Aluminum or Be diaphragms? Nice system! Did you explore other driver options? Just curious how you settled on the Radians.
Aluminum diaphragms. While I've used compression drivers in concert speakers for years, Justin has more experience using them in home speakers. He went with Radian because he's used them enough to trust their reliability and sound quality. Plus, the beryllium option provides a potential upgrade path.
 

russtafarian

Well-Known Member
Jul 12, 2012
25
44
318
Hey Russ, been awhile - looks like you are doing well!

KeithR
Keith,

Good to hear from you. I think the last time we connected was a late-night listening session at your place. Was it in Marina Del Rey? See you at THE Show this weekend?
 
  • Like
Reactions: KeithR

Artnet

Active Member
Mar 7, 2021
82
57
25
58
My friend Justin Weber is the visionary behind these speakers. Justin designs and builds tube amplifiers for his ampsandsound brand.
Just finished watching Justin Weber's you tube video on the Klughoerner and listening curiously about this very project. In searching for more I am very glad to have found the thread so thank you for sharing this inspiring journey. Very glad to see the finished product.
 

russtafarian

Well-Known Member
Jul 12, 2012
25
44
318
Update: August 22nd 2022

I’ve now had the horns for four months and have experimented with a few different system configurations. The setup has changed for the better since my first post so here’s an update.

The biggest setup challenge has been integrating the bass bin to both the room and the multicell midrange horn. When I initially installed the speakers, I didn’t understand why they sounded so thin when run full-range with a single amp. With two 12” woofers per side, a lack of bass was the last thing I expected. Bi-amping provided a quick fix and got me enjoying the speaker right away. That's the setup I documented in my first post.

So I did some basic research on how bass horns work. I looked at how horn size and shape impacts frequency response. I took simple frequency response measurements to see what the bass bins were doing in my room. I finally figured out what was going on.

My Front Loaded Horn bins are relatively compact in order to squeeze the speakers into a domestic environment. Standard VOTT sized bass bins would be ascetically too big for my room. However, the compact size of my bass bins means the horn loading only kicks in above 150 Hz. Below that, the bass bins transition from horn-loaded to direct radiation. This means the direct radiating output at 50 Hz is about 10 dB less than the horn loaded output above 150 Hz. Some of this is due to horn size and some of this is due to room interaction. I’m not bright enough to figure out what’s causing what, but it’s easy to see how this impacts the sound of the system.

Bi-amping is an easy fix. By using an active crossover and separately powering the bass bins I got a nicely balanced full-range response from the speakers. After doing the horn research, I learned why this works. I was using the active crossover to turn up the bass bins and filter out the extra horn gain above 200 Hz. I now understand why many VOTT devotees bi-amp them.

The big challenge was to get the speakers to work in my room with a single amp. Without some means of active frequency shaping, the speakers would deliver an in-room bass response worse than a pair of mini-monitors. This calls for (gasp!) equalization. Audiophiles are taught from a young age that equalizers are BAD! Why would I add something to my system that’s BAD! Well, many years in pro audio taught me that equalizers are tools that can yield GOOD results when used properly.

I started by inserting a Meyers Sound CP10 Parametric EQ between the preamp and power amp and found that I could build a pleasing frequency contour that smooths the bass response of the speakers down to 35 Hz. This was done primarily by cutting with multiple wide-Q filters. However, my nearly 30 year old CP-10 is not transparent enough to stay in the signal path. Studio room tuner Bob Hodas uses rebuilt CP-10s in many of the rooms he works in. I should ask him who he uses to rebuild them and send mine in for a refresh. Until that time…

I’m thankful for Schiit Audio and their wild obsession with building excellent yet inexpensive equalizers. The $1499 Loki Max is an amazing piece of engineering with remote control motorized filter controls and storable presets. The $299 Lokius is pretty much the same circuit but without the automation and big-ass chokes on the bass filters. Six bands, inductor-capacitor filters, quiet, wide-bandwidth circuit, balanced and unbalanced I/O. Bring it on!

Horns EQ.JPG

The first thing I did with the Lokius is put it on a spectrum analyzer to see how the filters work. Turning the middle two bands (400 Hz and 2 kHz) all the way down produced a smooth, even, -8 dB shelf from 200 to 8 kHz. Perfect! Inserting the Lokius between the preamp and power amp and reducing the two middle bands was all the speakers needed to deliver a smooth, musical response down to 35 Hz. As an added bonus, the Lokius serves as a balanced to single end converter for the power amp. I was able to remove the Lundahl transformer box at the amp’s input which resulted in a slight increase in system transparency.

Horns Amp & EQ.JPG

Is the Lokius completely transparent in the signal path with the filters engaged? No, but it’s pretty damn close. Depending on the quality of the source, I’m losing maybe 2% to 5% of what I get with a straight wire connection. I can live with that because the sound I’m getting with the EQ in play is freakin’ amazing. The system is now delivering all the magic I had hoped for. I feel very fortunate that Schiit designed and launched a reasonably priced equalizer that works so well for this application.

Horns with Amp & EQ.JPG
 

Ron Resnick

Site Co-Owner, Administrator
Jan 25, 2015
11,356
6,641
1,365
Beverly Hills, CA
Congratulations, Russ, on figuring all if this out, and on arriving at a very satisfactory outcome!
 
  • Like
Reactions: russtafarian

Tango

VIP/Donor
Mar 12, 2017
4,923
6,121
950
Bangkok
Update: August 22nd 2022

I’ve now had the horns for four months and have experimented with a few different system configurations. The setup has changed for the better since my first post so here’s an update.

The biggest setup challenge has been integrating the bass bin to both the room and the multicell midrange horn. When I initially installed the speakers, I didn’t understand why they sounded so thin when run full-range with a single amp. With two 12” woofers per side, a lack of bass was the last thing I expected. Bi-amping provided a quick fix and got me enjoying the speaker right away. That's the setup I documented in my first post.

So I did some basic research on how bass horns work. I looked at how horn size and shape impacts frequency response. I took simple frequency response measurements to see what the bass bins were doing in my room. I finally figured out what was going on.

My Front Loaded Horn bins are relatively compact in order to squeeze the speakers into a domestic environment. Standard VOTT sized bass bins would be ascetically too big for my room. However, the compact size of my bass bins means the horn loading only kicks in above 150 Hz. Below that, the bass bins transition from horn-loaded to direct radiation. This means the direct radiating output at 50 Hz is about 10 dB less than the horn loaded output above 150 Hz. Some of this is due to horn size and some of this is due to room interaction. I’m not bright enough to figure out what’s causing what, but it’s easy to see how this impacts the sound of the system.

Bi-amping is an easy fix. By using an active crossover and separately powering the bass bins I got a nicely balanced full-range response from the speakers. After doing the horn research, I learned why this works. I was using the active crossover to turn up the bass bins and filter out the extra horn gain above 200 Hz. I now understand why many VOTT devotees bi-amp them.

The big challenge was to get the speakers to work in my room with a single amp. Without some means of active frequency shaping, the speakers would deliver an in-room bass response worse than a pair of mini-monitors. This calls for (gasp!) equalization. Audiophiles are taught from a young age that equalizers are BAD! Why would I add something to my system that’s BAD! Well, many years in pro audio taught me that equalizers are tools that can yield GOOD results when used properly.

I started by inserting a Meyers Sound CP10 Parametric EQ between the preamp and power amp and found that I could build a pleasing frequency contour that smooths the bass response of the speakers down to 35 Hz. This was done primarily by cutting with multiple wide-Q filters. However, my nearly 30 year old CP-10 is not transparent enough to stay in the signal path. Studio room tuner Bob Hodas uses rebuilt CP-10s in many of the rooms he works in. I should ask him who he uses to rebuild them and send mine in for a refresh. Until that time…

I’m thankful for Schiit Audio and their wild obsession with building excellent yet inexpensive equalizers. The $1499 Loki Max is an amazing piece of engineering with remote control motorized filter controls and storable presets. The $299 Lokius is pretty much the same circuit but without the automation and big-ass chokes on the bass filters. Six bands, inductor-capacitor filters, quiet, wide-bandwidth circuit, balanced and unbalanced I/O. Bring it on!

View attachment 97118

The first thing I did with the Lokius is put it on a spectrum analyzer to see how the filters work. Turning the middle two bands (400 Hz and 2 kHz) all the way down produced a smooth, even, -8 dB shelf from 200 to 8 kHz. Perfect! Inserting the Lokius between the preamp and power amp and reducing the two middle bands was all the speakers needed to deliver a smooth, musical response down to 35 Hz. As an added bonus, the Lokius serves as a balanced to single end converter for the power amp. I was able to remove the Lundahl transformer box at the amp’s input which resulted in a slight increase in system transparency.

View attachment 97119

Is the Lokius completely transparent in the signal path with the filters engaged? No, but it’s pretty damn close. Depending on the quality of the source, I’m losing maybe 2% to 5% of what I get with a straight wire connection. I can live with that because the sound I’m getting with the EQ in play is freakin’ amazing. The system is now delivering all the magic I had hoped for. I feel very fortunate that Schiit designed and launched a reasonably priced equalizer that works so well for this application.

View attachment 97121
Congratulation sir! Cost less, more practical, but great sound, that's a true Winner in my book.
 

bonzo75

Member Sponsor
Feb 26, 2014
18,869
8,997
1,515
London
Update: August 22nd 2022

I’ve now had the horns for four months and have experimented with a few different system configurations. The setup has changed for the better since my first post so here’s an update.

The biggest setup challenge has been integrating the bass bin to both the room and the multicell midrange horn. When I initially installed the speakers, I didn’t understand why they sounded so thin when run full-range with a single amp. With two 12” woofers per side, a lack of bass was the last thing I expected. Bi-amping provided a quick fix and got me enjoying the speaker right away. That's the setup I documented in my first post.

So I did some basic research on how bass horns work. I looked at how horn size and shape impacts frequency response. I took simple frequency response measurements to see what the bass bins were doing in my room. I finally figured out what was going on.

My Front Loaded Horn bins are relatively compact in order to squeeze the speakers into a domestic environment. Standard VOTT sized bass bins would be ascetically too big for my room. However, the compact size of my bass bins means the horn loading only kicks in above 150 Hz. Below that, the bass bins transition from horn-loaded to direct radiation. This means the direct radiating output at 50 Hz is about 10 dB less than the horn loaded output above 150 Hz. Some of this is due to horn size and some of this is due to room interaction. I’m not bright enough to figure out what’s causing what, but it’s easy to see how this impacts the sound of the system.

Bi-amping is an easy fix. By using an active crossover and separately powering the bass bins I got a nicely balanced full-range response from the speakers. After doing the horn research, I learned why this works. I was using the active crossover to turn up the bass bins and filter out the extra horn gain above 200 Hz. I now understand why many VOTT devotees bi-amp them.

The big challenge was to get the speakers to work in my room with a single amp. Without some means of active frequency shaping, the speakers would deliver an in-room bass response worse than a pair of mini-monitors. This calls for (gasp!) equalization. Audiophiles are taught from a young age that equalizers are BAD! Why would I add something to my system that’s BAD! Well, many years in pro audio taught me that equalizers are tools that can yield GOOD results when used properly.

I started by inserting a Meyers Sound CP10 Parametric EQ between the preamp and power amp and found that I could build a pleasing frequency contour that smooths the bass response of the speakers down to 35 Hz. This was done primarily by cutting with multiple wide-Q filters. However, my nearly 30 year old CP-10 is not transparent enough to stay in the signal path. Studio room tuner Bob Hodas uses rebuilt CP-10s in many of the rooms he works in. I should ask him who he uses to rebuild them and send mine in for a refresh. Until that time…

I’m thankful for Schiit Audio and their wild obsession with building excellent yet inexpensive equalizers. The $1499 Loki Max is an amazing piece of engineering with remote control motorized filter controls and storable presets. The $299 Lokius is pretty much the same circuit but without the automation and big-ass chokes on the bass filters. Six bands, inductor-capacitor filters, quiet, wide-bandwidth circuit, balanced and unbalanced I/O. Bring it on!

View attachment 97118

The first thing I did with the Lokius is put it on a spectrum analyzer to see how the filters work. Turning the middle two bands (400 Hz and 2 kHz) all the way down produced a smooth, even, -8 dB shelf from 200 to 8 kHz. Perfect! Inserting the Lokius between the preamp and power amp and reducing the two middle bands was all the speakers needed to deliver a smooth, musical response down to 35 Hz. As an added bonus, the Lokius serves as a balanced to single end converter for the power amp. I was able to remove the Lundahl transformer box at the amp’s input which resulted in a slight increase in system transparency.

View attachment 97119

Is the Lokius completely transparent in the signal path with the filters engaged? No, but it’s pretty damn close. Depending on the quality of the source, I’m losing maybe 2% to 5% of what I get with a straight wire connection. I can live with that because the sound I’m getting with the EQ in play is freakin’ amazing. The system is now delivering all the magic I had hoped for. I feel very fortunate that Schiit designed and launched a reasonably priced equalizer that works so well for this application.

View attachment 97121


The B&K solid state amps might be cause of the problem. On Altec woofers having SS amps with grip chokes then and reduces bass. They do very well with low watt amps that have less grip and high output impedance. I don't know how your eminent delta woofers work but do check
 

About us

  • What’s Best Forum is THE forum for high end audio, product reviews, advice and sharing experiences on the best of everything else. This is THE place where audiophiles and audio companies discuss vintage, contemporary and new audio products, music servers, music streamers, computer audio, digital-to-analog converters, turntables, phono stages, cartridges, reel-to-reel tape machines, speakers, headphones and tube and solid-state amplification. Founded in 2010 What’s Best Forum invites intelligent and courteous people of all interests and backgrounds to describe and discuss the best of everything. From beginners to life-long hobbyists to industry professionals, we enjoy learning about new things and meeting new people, and participating in spirited debates.

Quick Navigation

User Menu

Steve Williams
Site Founder | Site Owner | Administrator
Ron Resnick
Site Co-Owner | Administrator
Julian (The Fixer)
Website Build | Marketing Managersing