Hi, i need some advice designing a full range 4 way horn system. For now i have a set of altec A7 in my listening room witch i really like. They are loaded with Altec 421's, 511 horn's and 902's, crossover is active. Problem is they are a bit big, they do not really so well in the low (-60 hz) , the same in the high above 7 Khz. So i want a new design, full front loaded horn (not hybride like the A7) with these components i already have. I think splitting the design in a front loaded folded horn from 40 - 200 Hz (Tuba design), a mid-bass horn using the 421's from 200 - 700 Hz (front loaded horn, 200 hz should make it pretty short), above 700 Hz till about 6 Khz the 511 horn with Altec 902 drivers and above a jbl 2405 horn tweeter. Any suggestions about this design? It will be used in house, not as a Pa speaker system...
I would suggest you avoid the Fitzmaurice products for home Hi-Fi. Do some Google searches and research. Unless you can live with a very sizeable horn a more practical low frequency horn would be a tapped horn. Which model of 421 do you have? H series, Series II, or LF? Which model of 902 do you have? I would not recommend the JBL 2405. There are modern super tweeters that perform so much better. Examples: B&C Speakers DE35, Faital Pro FD371, Beyma CP-22, etc. There are much better mid range horns than the 511. Both Tractrix and LeCleach horns sound better than the 511 – I know firsthand and there is no comparison.
Thank you for the response. About the lowest horn part, i was tempted by the the Fitzmaurice tuba line because they are all relative small for a front loaded horn design. Also, as i want to keep a rather small midbass horn, i am limited in hornlenght so the bass horn will need to be playing from 40 hz till about 200 hz, i do not now if this could be covered through a tapped horn...
The 421 is a series II, 902-8a.
I can replace my altec components with newer replacement, but only if i can couple them to good diy horn designs.
How is the sound from a front loaded bass horn compared to a tapped horn, as a tapped horn works partial as a reflex port?
The 421 is a series II, 902-8a.
I can replace my altec components with newer replacement, but only if i can couple them to good diy horn designs.
How is the sound from a front loaded bass horn compared to a tapped horn, as a tapped horn works partial as a reflex port?
A tapped horn is a horn that is designed to use the radiation from both sides of the cone where you would normally see dips in response from having a horn mouth that is too small to support lower frequencies. It works marvelously well and is probably the most significant advancement in horn technology in recent history. The primary limitation is they are good for only 2 to 2.5 octaves. There are several people using reasonable sized 80Hz to 100Hz mid bass horns and crossing over to a tapped horn for the lower frequencies.
see this link for the white paper on tapped horns --> http://www.danleysoundlabs.com/danley/wp-content/uploads/2012/01/The-Tapped-Horn.pdf
see this link for the white paper on tapped horns --> http://www.danleysoundlabs.com/danley/wp-content/uploads/2012/01/The-Tapped-Horn.pdf
You can use your 421 -II in a hyperbolic-exponential ( T=0.7 ) front loaded mid bass horn. 242cm^2 throat, 3856cm^2 mouth, and with a horn length of 76cm. Back chamber volume of around 8.5 liters. SPL should be right around 106db 1W/1M and the -6dB points would be 100Hz and about 550Hz. You'll need something to bridge between this and where the 902 can play down to.
I'm afraid my wife will not like the idea of a straight horn with a lenght of +- 100 cm (76 cm hornlenght + depth of the enclosure for the 421), she already complaints about the A7's...
If i would make the horn shorter, to say about max 50 cm hornlenght, the hornloading will rise to about 160 hz? I do not think i can fit a tapped horn under it that wil go that high without distortion?
Although some tapped horns on the website from Mr. Danley are claimed to go that high and even higher (TH-115 from 40 - 200 hz)?
If i would make the horn shorter, to say about max 50 cm hornlenght, the hornloading will rise to about 160 hz? I do not think i can fit a tapped horn under it that wil go that high without distortion?
Although some tapped horns on the website from Mr. Danley are claimed to go that high and even higher (TH-115 from 40 - 200 hz)?
I always wondered how they do these things at Blumenhofer's. They have the 'Clara Luna', hybrid system containing a short midrange horn in a closed cabinet with a TAD woofer and a 21 inch subwoofer below it, crossing over at 50 Hz. If i look at how long the midrange horn is, i wonder how its is possible to push te tad woofer further down to 50 hz in a cabinet that small without porting?
Horn system, or not ?
Greetings,
You are asking advice on "how to do" a 4way horn system, and then saying you are not allowed to have a 4 way horn system because it will be too large.
You have engaged probably the best horn designer in this thread. Consider yourself fortunate [for that].
Perhaps in keeping the peace in your domestic residence, you could opt for an
all active 4-way direct radiator system. Horns match horns, and direct radiators match each other as well. An all active system will give you more dynamics than would otherwise be possible with a conventioanl speaker system. Using a modular approach (by that I mean each section of it's own)
giving some flexibilty for future experiments/and/or upgrades.
Greetings,
You are asking advice on "how to do" a 4way horn system, and then saying you are not allowed to have a 4 way horn system because it will be too large.
You have engaged probably the best horn designer in this thread. Consider yourself fortunate [for that].
Perhaps in keeping the peace in your domestic residence, you could opt for an
all active 4-way direct radiator system. Horns match horns, and direct radiators match each other as well. An all active system will give you more dynamics than would otherwise be possible with a conventioanl speaker system. Using a modular approach (by that I mean each section of it's own)
giving some flexibilty for future experiments/and/or upgrades.
I consider myself very happy with all the responses i receive for this post and the help this forum is giving me. Of all the speakersystems i have had in my place, going from commercial designs (B&W DM12 monitors, B&W 604), jbl's with E-145 diy, JBL 4530 backloaded horn to the Altec's in bass reflex enclosures and in horn enclosures (A7), i like the front loaded horn enclosure the best (to my ears 🙂 ). I am doing since quiet some time research developing an enclosure to replace the A7's and improve their faults. I have been on the sites from volvotreter, Mr. Cowan, inlowsound, Mr. Danley and here. Every mid horn i have seen goes to 100 hz but is around 100 cm deep ( much deeper then the altec A7). So i asked myself it it would be possible to design a mid horn that is less deep with a higher crossover frequency , completed with a folded or tapped horn below it that will go that high. I now things are easier considering a bigger mid horn, but i think if i would build them that big, they will not be in my room for a long time, because they would be to big. So i wonder if there would be another solution...
How about seal the A7 up , tune the back chamber and use it 150 Hz up? Then build some tapped horns or corner horns for the bass. If you cut the wasted space off the A7 and place the short horn on the floor it will go lower, maybe 120 cycles if you have a solid floor
Oliebaron:
Do a search on Inlow sound and Volvotreter for a look performance and size comparison. The top of the line fostex tweeter is excellent but expensive. What size is your room ?
Do a search on Inlow sound and Volvotreter for a look performance and size comparison. The top of the line fostex tweeter is excellent but expensive. What size is your room ?
I understand the difficulty in trying to fit a long straight mid bass horn into a room. The next logical step would be to fold the horn. Many successful systems have been built using a folding method very similar to the University Classic horn. Take a look at the “Show Horn” and “Monolith” horn articles in the download section of Volvtreter’s website.
Link: Volvotreter Download Section
If you avoid folds greater than 90 degrees and follow the principles of Huygen’s wavefront reconstruction theorem, your folded horn will have few compromises.
EDIT: Due to path length differences DSP to delay the folded horn should be considered for best integration results.
Link: Volvotreter Download Section
If you avoid folds greater than 90 degrees and follow the principles of Huygen’s wavefront reconstruction theorem, your folded horn will have few compromises.
EDIT: Due to path length differences DSP to delay the folded horn should be considered for best integration results.
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Provided the woofer has the correct T/S parameters it’s not too difficult to get a 15" to reach 50Hz in a 3.5 cu. ft. sealed enclosure. One thing to consider is the importance of phase alignment when mixing horns and direct radiators. Take a look at the "Quasi-optimal" crossover thread. You should find it an interesting read.
Link: http://www.diyaudio.com/forums/mult...sover-high-efficiency-loudspeaker-system.html
Not being a speaker guru, my thoughts are that the audio frequency range should be split roughly equally among the 4 horn loaded drivers.
That means ~ 2½ to 3 octaves from the active crossovers into Horn/Drivers that are clean and even over >3octaves.
That means ~ 2½ to 3 octaves from the active crossovers into Horn/Drivers that are clean and even over >3octaves.
That can work at times. I normally look to avoid placing a crossover in any of the critical areas where the ear is most sensitive. I then design horns that will span over these areas as to not violate them. The natural break points seem to fall at 80Hz-100Hz, 400Hz-600Hz, and 1500Hz-2000Hz.
Ok, i get a lot of response and different opinions here, that is great!
Let's say to try to make a full horn design, 3 or 4-way, with about the dimensions of an altec A7 (about 100 cm high, 75 cm wide and 60 cm deep) (42 inch high, 30 inch wide, 24 inch deep).
This to fit in a regular european livingroom, i am from Belgium, mine is about 8m deep and 4 m wide and the speaker are aimed to the wide side (4 m).
Also i would take the crossoversettings in mind said before as much as possible (100hz-500hz-1500hz) considering the altec 421 and 902
So possible solutions:
1: a folded horn
advantage: less deep and smaller, possible as a 3 way? (crossover 40-500 Hz?)
disadvantage: compromised sound quality if not made good?, frequencyrange not big enough (no 3 way possible?)
2: a shorter straight midbasshorn
advantage: sound quality, possible differences between bass enclosure and mid enclosure can be more easily altered
disadvantage: higher crossoverpoint makes it difficult to mate it to a tapped sub horn enclosure?, always 4-way (crossover from 150-500 hz?)
This is how far i am right now, i like to see your opinions...🙂
Kris
Let's say to try to make a full horn design, 3 or 4-way, with about the dimensions of an altec A7 (about 100 cm high, 75 cm wide and 60 cm deep) (42 inch high, 30 inch wide, 24 inch deep).
This to fit in a regular european livingroom, i am from Belgium, mine is about 8m deep and 4 m wide and the speaker are aimed to the wide side (4 m).
Also i would take the crossoversettings in mind said before as much as possible (100hz-500hz-1500hz) considering the altec 421 and 902
So possible solutions:
1: a folded horn
advantage: less deep and smaller, possible as a 3 way? (crossover 40-500 Hz?)
disadvantage: compromised sound quality if not made good?, frequencyrange not big enough (no 3 way possible?)
2: a shorter straight midbasshorn
advantage: sound quality, possible differences between bass enclosure and mid enclosure can be more easily altered
disadvantage: higher crossoverpoint makes it difficult to mate it to a tapped sub horn enclosure?, always 4-way (crossover from 150-500 hz?)
This is how far i am right now, i like to see your opinions...🙂
Kris
A shorter horn ?
Would it not be possible to get away with a shorter horn if one made the throat larger ?
When I look at the Altec A7 types, it does not seem natural (at least to me, but what do I know?) to have a driver firing into planks of wood each side of
the throat of the horn.
I have often wondered if (mid) horn loading down to 150 Hz would be adaquate to still convey the dynamic horn quality, but in a more domestic-friendly enviromnent?
Below 150Hz, audio propogation tends to be omni-directional anyway, so a direct radiating woofer below the 150Hz mid-horn might be an acceptable
solution. I just don't know if one 15" driver(woofer)/per side would keep up with a horn-loaded midrange (?)
Would it not be possible to get away with a shorter horn if one made the throat larger ?
When I look at the Altec A7 types, it does not seem natural (at least to me, but what do I know?) to have a driver firing into planks of wood each side of
the throat of the horn.
I have often wondered if (mid) horn loading down to 150 Hz would be adaquate to still convey the dynamic horn quality, but in a more domestic-friendly enviromnent?
Below 150Hz, audio propogation tends to be omni-directional anyway, so a direct radiating woofer below the 150Hz mid-horn might be an acceptable
solution. I just don't know if one 15" driver(woofer)/per side would keep up with a horn-loaded midrange (?)
Isn't there a big difference between the efficiency produced by the horn and the db produced by the driver acting as a direct radiating driver below the lowest frequency of the horn? i will read the thread as you discribed, i have a jbl design with horn/direct radiator, sure will be usefull!
Oliebaron:
A descent mid bass horn could be a little smaller than the A7 altec except for the depth which can be from 30" to 36 " depending on the low frequency of the horn chosen.
Another benefit of a straight horn is the easier time alignment with the other drivers.
If you can afford the extra depth of the straight horn, that would be my #1 choice. Ideally you would want a mid bass horn to go down to 80-100hz and then cross to a sub/tapped horn. Most tapped horns do not sound good above about 100hz or so.
JLH is the real expert on horns and I have him to thank for my present system as I have read just about all his posts in the last several years on horns. I use a straight horn and have heard nothing better. JLH, thanks for sharing your knowledge over the years !!! I am sure you helped many diy horn builders along the way.
A descent mid bass horn could be a little smaller than the A7 altec except for the depth which can be from 30" to 36 " depending on the low frequency of the horn chosen.
Another benefit of a straight horn is the easier time alignment with the other drivers.
If you can afford the extra depth of the straight horn, that would be my #1 choice. Ideally you would want a mid bass horn to go down to 80-100hz and then cross to a sub/tapped horn. Most tapped horns do not sound good above about 100hz or so.
JLH is the real expert on horns and I have him to thank for my present system as I have read just about all his posts in the last several years on horns. I use a straight horn and have heard nothing better. JLH, thanks for sharing your knowledge over the years !!! I am sure you helped many diy horn builders along the way.
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