I'll leave that to Steve as amps go about 10 foot over my head at the moment -all I've ever built were Nelson Pass's Zen amps, and a few tweaked t-amps.
Regarding the horns, your first port of call needs to be Martin's massive horn theory and design white papers. In a sense, yes, you are right: the filter chamber volume and throat CSA determine the upper FR cutoff of the horn, and below that, the flare rate, mouth CSA and length determine the LF cut off and acoustic gain. The double horns, for example, do indeed work like reflex enclosures in the LF regions. Smaller filter chambers and longer horns tend to behave more like QWRs.
Regarding the horns, your first port of call needs to be Martin's massive horn theory and design white papers. In a sense, yes, you are right: the filter chamber volume and throat CSA determine the upper FR cutoff of the horn, and below that, the flare rate, mouth CSA and length determine the LF cut off and acoustic gain. The double horns, for example, do indeed work like reflex enclosures in the LF regions. Smaller filter chambers and longer horns tend to behave more like QWRs.
With Steve's permission, pray tell us more - or even pictures(?)
Hi chrisb,
the amps i used where home made jobs..
I'm a geat beliver in less is more where amps are concerned, providing the quality of the components is high
there are pictures of my horns and amps on steve's metronome thread.. see his website and look at the pictures for the eggfests
eggfest 3 has the latest amp on it...
my speakers have remained unchanged for nearly six years
but i have done alot to the amps in this time..
my bigger amp uses det25 output valves these are rare, driven by 41mh globes, and tribute amorphous core output transormers
these are both high gain valves and manage to run them without bypass on the cathodes which gives a slightly better sound than with .. but much less gain.. i'm getting 3-4 watts but musical peaks have been measured at 115db's +.. so more than enough volume.
my second amp is on a breadboard, it's 41mp driving 41mp
these again are old cosser valves but with hammond output transformers.. it has a very nice sound .. not quite as much bass as the bigger amp..these again are mesh plate globes and give around 1 watt
these are indirectly heated valves and sound every bit as good as directly heated.. maybe better..so there goes one myth...
i have a collection of old british valves and have used px4 & px25 in the past.. and maybe in the future.. trouble is these valves are valuable.. so they lay in a box..
... but they are very good sounding
other rare valves i have and intend to build with are cosser 2p, 41mxp, and some old 30's pentodes that in pentode mode run at near triode distortion levels.. so loads to go at...
speaker wise my horns are 3.6 m back loaded.. that i think where designed to go down to 38 hz, they do that easily and more..
they are my own design but i've lost the plans i had,.. having moved house twice since i made them,
they are back firing and work best placed as corner horns, they have lowther ex4 drivers
in the past i have used pm6/pm6a/pm2/dx3 in various back hornsj (and yam ns1000's) these in my view the best by far ...
so far...
i intend to build some replacements I hoping to get a 4.7 m horn in a proper corner enclosure, using the wall as one side of the horn mouth... ..
well see how they go...
cheers steve
Hi chrisb,
the amps i used where home made jobs..
I'm a geat beliver in less is more where amps are concerned, providing the quality of the components is high
there are pictures of my horns and amps on steve's metronome thread.. see his website and look at the pictures for the eggfests
eggfest 3 has the latest amp on it...
my speakers have remained unchanged for nearly six years
but i have done alot to the amps in this time..
my bigger amp uses det25 output valves these are rare, driven by 41mh globes, and tribute amorphous core output transormers
these are both high gain valves and manage to run them without bypass on the cathodes which gives a slightly better sound than with .. but much less gain.. i'm getting 3-4 watts but musical peaks have been measured at 115db's +.. so more than enough volume.
my second amp is on a breadboard, it's 41mp driving 41mp
these again are old cosser valves but with hammond output transformers.. it has a very nice sound .. not quite as much bass as the bigger amp..these again are mesh plate globes and give around 1 watt
these are indirectly heated valves and sound every bit as good as directly heated.. maybe better..so there goes one myth...
i have a collection of old british valves and have used px4 & px25 in the past.. and maybe in the future.. trouble is these valves are valuable.. so they lay in a box..
... but they are very good sounding
other rare valves i have and intend to build with are cosser 2p, 41mxp, and some old 30's pentodes that in pentode mode run at near triode distortion levels.. so loads to go at...
speaker wise my horns are 3.6 m back loaded.. that i think where designed to go down to 38 hz, they do that easily and more..
they are my own design but i've lost the plans i had,.. having moved house twice since i made them,
they are back firing and work best placed as corner horns, they have lowther ex4 drivers
in the past i have used pm6/pm6a/pm2/dx3 in various back hornsj (and yam ns1000's) these in my view the best by far ...
so far...
i intend to build some replacements I hoping to get a 4.7 m horn in a proper corner enclosure, using the wall as one side of the horn mouth... ..
well see how they go...
cheers steve
I suspect so. Wish I could build like that. EX3 I believe.
Steve's EX3 drivers were the finest I've ever heard, and I don't say that lightly. In his BLHs, powered by his amps, they were thundering in the mid 30Hz regions -enough to vibrate his ceiling lamp-shade. Good horn design. Not small, but worth it. Look good too. If I ever hear anyone say that Lowther's can't do bass, I intend, with Steve's permission, to stuff his head down the mouth of one of his horns, and crank up Massive Attack. Which we listened to on Wednesday to grin-inducing effect. I've only ever head that sort of bass from BIBs with FF225Ks before. Very impressive indeed.
Steve's EX3 drivers were the finest I've ever heard, and I don't say that lightly. In his BLHs, powered by his amps, they were thundering in the mid 30Hz regions -enough to vibrate his ceiling lamp-shade. Good horn design. Not small, but worth it. Look good too. If I ever hear anyone say that Lowther's can't do bass, I intend, with Steve's permission, to stuff his head down the mouth of one of his horns, and crank up Massive Attack. Which we listened to on Wednesday to grin-inducing effect. I've only ever head that sort of bass from BIBs with FF225Ks before. Very impressive indeed.
I am really fond of my double horns. My wife & I made them in the weekends over some 6 months. The harder the work - the greater the love.
Apart from that I really think they sound great. I have made no meassurements other than lending some critical ears to my music and what really is an earopener from these speakers compared to the other horns I designed over the years is the bass section down to around 45-50 Hz. It apperes flat as my wallet. I can follow the bass guitar up the mountain, down the valley without missing a note here & there. Another quality is the solidity of the construction. I have not yet succeeded in bringing the beast to tremble and I have really pumped up the volume. Sometimes in the evening, when we are sitting in the garden, we open the windows in the livingroom & put the volume knob in the 12 o'clock position and leave the room in some microseconds.
I started out with some 50W NAD amplifier but replaced it later with a new build of Linsley Hood's 96 design with double capacitance multipliers and MJ15003 adjusted to +/- 21v, 2A qc. This expanded the frq area downwards to around 45-50 Hz and what really came as a shock to me. The music went farther from the speakers. I could leave the room & still here almost all of the music in the room next door or outside the house. Don't ask me how or why.
The speakers are equipped with EX3 but I removed the phaseplug because I think they curlied up the middletone a bit (actually I replaced them by the centrething from my DX2 upstairs) I think I got a much more clean middletone downstairs and a slightly damped middletone section upstairs which was a plus especially when playing loud. It might have something to do with the way the 2 systems are designed. Upstairs the design is traditionally built with the labyrinth starting at some 90 degrees angle to the direction of the driversound. I therefore get a great deal of reflexion back through the driver. Downstairs the lab starts out in the "right" direction and I get less reflexion.
With respect to plans. I did not create these speakers with the intention to do it again, so I am a little low on documentation. My wife told me to keep the kabinet within 30 x 50 cm groundarea. I am a software engineer for a living and created a program to help me calculate and fold a horn in a square box & I soon realized that I could do no horn without splitting it up. It is calculated to go down to 59 Hz placed in a corner. It goes down a bit further than that but physics are hard to bend. Upstairs I have a subhorn built into the roof construction calculated to 30 Hz 4,5 m straigt triangle. She can play notes you cannot hear.
I must be off for now - dinner is served
Apart from that I really think they sound great. I have made no meassurements other than lending some critical ears to my music and what really is an earopener from these speakers compared to the other horns I designed over the years is the bass section down to around 45-50 Hz. It apperes flat as my wallet. I can follow the bass guitar up the mountain, down the valley without missing a note here & there. Another quality is the solidity of the construction. I have not yet succeeded in bringing the beast to tremble and I have really pumped up the volume. Sometimes in the evening, when we are sitting in the garden, we open the windows in the livingroom & put the volume knob in the 12 o'clock position and leave the room in some microseconds.
I started out with some 50W NAD amplifier but replaced it later with a new build of Linsley Hood's 96 design with double capacitance multipliers and MJ15003 adjusted to +/- 21v, 2A qc. This expanded the frq area downwards to around 45-50 Hz and what really came as a shock to me. The music went farther from the speakers. I could leave the room & still here almost all of the music in the room next door or outside the house. Don't ask me how or why.
The speakers are equipped with EX3 but I removed the phaseplug because I think they curlied up the middletone a bit (actually I replaced them by the centrething from my DX2 upstairs) I think I got a much more clean middletone downstairs and a slightly damped middletone section upstairs which was a plus especially when playing loud. It might have something to do with the way the 2 systems are designed. Upstairs the design is traditionally built with the labyrinth starting at some 90 degrees angle to the direction of the driversound. I therefore get a great deal of reflexion back through the driver. Downstairs the lab starts out in the "right" direction and I get less reflexion.
With respect to plans. I did not create these speakers with the intention to do it again, so I am a little low on documentation. My wife told me to keep the kabinet within 30 x 50 cm groundarea. I am a software engineer for a living and created a program to help me calculate and fold a horn in a square box & I soon realized that I could do no horn without splitting it up. It is calculated to go down to 59 Hz placed in a corner. It goes down a bit further than that but physics are hard to bend. Upstairs I have a subhorn built into the roof construction calculated to 30 Hz 4,5 m straigt triangle. She can play notes you cannot hear.
I must be off for now - dinner is served
Dear Scottmoose
I am very fasinated after seeing your work (the double horn). A very good job.
I have search for many speaker designs that may suit my tube gear and taste. However,I still cannot make up my mind for which speaker project to go.
I have considered Mr. Martin King's TQWT but it require a circuit for balancing the frequency response to get the bass. However that also lower the efficiency to around 87db and I am a bit worry wheather it may suit my low power tube amp. Bob's straight pip is nice but it alos need a correction circuit (Do you know what is its efficiency). The Hedlund seems very attractive. It doesn't need a circuit but it is too difficult to build.
Your double horn seems to be very a good idea for me in view of its small foot print and simplicity for building. But it require many angular edge cutting to a specific angle. It is the most difficult part to me. I have in my mind an alternative construction that that avoid angular edge cutting. It also replace the sharp bending edge with smooth curve. Although it is just a concept, I think it should work. I have not yet decide the driver to be installed so the dimension is only roughly follow yours. I have attached a pdf for the construction scheme.
I have some question regarding your double horn:
1.Do you think this double horn can suit a 6.5" Fostex?
2.What is the efficiency of your double horn?
3.Can you compare the sould between the double horn with Mr. Martin King's TQWT you have build before?
4.How about the bass extension?
Thanks a lot
I am very fasinated after seeing your work (the double horn). A very good job.
I have search for many speaker designs that may suit my tube gear and taste. However,I still cannot make up my mind for which speaker project to go.
I have considered Mr. Martin King's TQWT but it require a circuit for balancing the frequency response to get the bass. However that also lower the efficiency to around 87db and I am a bit worry wheather it may suit my low power tube amp. Bob's straight pip is nice but it alos need a correction circuit (Do you know what is its efficiency). The Hedlund seems very attractive. It doesn't need a circuit but it is too difficult to build.
Your double horn seems to be very a good idea for me in view of its small foot print and simplicity for building. But it require many angular edge cutting to a specific angle. It is the most difficult part to me. I have in my mind an alternative construction that that avoid angular edge cutting. It also replace the sharp bending edge with smooth curve. Although it is just a concept, I think it should work. I have not yet decide the driver to be installed so the dimension is only roughly follow yours. I have attached a pdf for the construction scheme.
I have some question regarding your double horn:
1.Do you think this double horn can suit a 6.5" Fostex?
2.What is the efficiency of your double horn?
3.Can you compare the sould between the double horn with Mr. Martin King's TQWT you have build before?
4.How about the bass extension?
Thanks a lot
vangogh-hk said:
Well now, I actually have less than what most people would call the minimum necessary tools for building, but they turned out fairly well. You just have to take some time. Your curved approach looks great, no reason why you can't go for that. Regarding your questions
1) As-is, no. The one that has the most chance of passably working is the defunct, non 'E' FE168Sigma, but they're really designed for drivers with parameters usually seen in 4 - 4 1/2in units. I'm working on a different one for 8in units at the moment with greater horn length and mouth size
2) I haven't measured the in-room efficiency, but we ran them at comfortable volumes using a variety of music -everything from folk to PJ Harvey with a 1w SE amp at Steve's house last Wednesday, and there didn't appear to be any problems with headroom.
3) Not really, it's apples and oranges; the one is a horn, the other a mass-loaded, chamberless horn variation (i.e an ML TQWT). I still love Martin's ML TQWT I hasten to add -they're a great cabinet, but they do have different priorities. They go a little lower, but have less efficiency, so dynamics are a little more constrained, and sound smaller. Imaging is about equal, with perhaps an edge going to the horns, mainly due to the smaller driver. The ML TQWTs remind me more of the monitor sound, and are more forgiving of room-positioning -the horns hate side-walls, and subjectively at least sound faster.
4) With Steve's SE amps, we got a pretty firm bottom-string bass guitar (i.e. 41Hz) out of them in-room.
GM said:
Hi Greg
I think they're better than the smaller BIBs, but it'd probably come down to personal taste. The latter have an edge in dynamics, but these go just as low, and have better scale, with less ripple too, without being restricted to corners. I reckon the sweet spot for the BIBs is with drivers in the ~ 5in-7in regions; even with floor-coupling, the smaller ones loose some of the impact and scale the larger versions provide. Just giving options / alternatives really.
Scott
Sorry it's taken longer than I expected, but the dimensions for the double horns with 8in Fostex units are now pretty much firming up. I got them to Dave last week, before I went away. The real issue was getting the folding scheme right, but I think we've got a good a nice one on the way. A few tweaks are needed, but it's progressing again. 1/2 space (no room-gain) response attached.
External dimensions are larger than the 126 horns, obviously, but not by much, relatively. It's 10in taller, about 1.25in deeper and 2.5in wider. Doubled side, front & rear panels might be a good idea because we're going low here. In room we should be flat to about 28Hz. Not the usual horn response I know, but variety is the spice of life!
Best
Scott
External dimensions are larger than the 126 horns, obviously, but not by much, relatively. It's 10in taller, about 1.25in deeper and 2.5in wider. Doubled side, front & rear panels might be a good idea because we're going low here. In room we should be flat to about 28Hz. Not the usual horn response I know, but variety is the spice of life!
Best
Scott
Attachments
First CAD drawings are now complete. Dave suggested calling it the Son of Harvey doublehorn, which sounds favourite to me. Only question is -do we need a Daughter of Harvey doublehorn for the 16x series?
Best not -yet. Dave'll be after me with a shotgun if I suddenly drop another on him.
Scott
Best not -yet. Dave'll be after me with a shotgun if I suddenly drop another on him.
Scott
Scottmoose said:First CAD drawings are now complete. Dave suggested calling it the Son of Harvey doublehorn, which sounds favourite to me. Only question is -do we need a Daughter of Harvey doublehorn for the 16x series?
Best not -yet. Dave'll be after me with a shotgun if I suddenly drop another on him.
No, no, 16x "of Harvey" was expected, from Son of Harvey, spawn of Frugel-Horn, comes Iris, Duagher of Harvey Horn ... a lovely mix of the finese of the smaller & the bass & dynamics of the larger...
Sounds very viking... that family can join Fonken, Mama Fonken, and Papa Fonken, and maybe Baby Fonken.
dave
here is the sketch... plans are non complete, but enough to build one. Mail me if you want one.
Attachments
Son of Harvey with the Fostex FE208ESigma, just in case anyone wanted to know what happens when you put a lower Q driver in it.
Something good, that's for sure... FE206E looks similar. In room, they should be flat to the mid 20s (apart from a bit of ripple, which isn't much as horns go), with sensitivity up around 96db for 1w. The original 126 based Harvey Horn, with valves, and in a decently sized room will give a solid 40Hz; far lower than I anticipated, so I'm being a bit conservative here -I have a suspicion that ~20Hz is on the cards if current experience is anything to go by. These things really do couple to a room well.
A Daughter of Harvey double horn with the FE166E? Best get MathCad fired up... Be nice to complete the family.
Something good, that's for sure...
FE206E looks similar. In room, they should be flat to the mid 20s (apart from a bit of ripple, which isn't much as horns go), with sensitivity up around 96db for 1w. The original 126 based Harvey Horn, with valves, and in a decently sized room will give a solid 40Hz; far lower than I anticipated, so I'm being a bit conservative here -I have a suspicion that ~20Hz is on the cards if current experience is anything to go by. These things really do couple to a room well.A Daughter of Harvey double horn with the FE166E? Best get MathCad fired up... Be nice to complete the family.
