Hello,
I am fairly new to high sensitivity horn style speakers, esp these rear loaded horn types. I have been building tube gear for some time now but generally the higher powered PP types of amps. I have recently taken an interest in the DHT / SET low powered designs and am in the process of sourcing parts for a build of the Wilson MK1 300B. I know that this new direction is going to require some different speakers with higher sens. than my current Proac 2.5s and Polk M10 speakers. Because of this I am also planning on building a speaker based on the Fostex 206 series driver. I have been hunting for the "perfect" DIY enclosure but have some serious concerns about the frequency response dips I see inherent in the rear loaded horn designs. The Frugal-Horn website has a perfect case in point. The Sachico has wonderful reviews but I can honestly say that I am skeptical given the response graphs that are shown (Here: http://homepage.mac.com/tlinespeakers/FH/images/Sachico-modeled-FR.gif ).
These are some pretty nasty dips that I would find totally unacceptable in the modeling of any 2 or 3 way design I have built or would build. But the reviews.....what about the reviews? They all claim the wondrous sound of these designs.
Well, based on my concerns I am here for some more subjective (and possibly objective) reviews of these speakers....particularly these Sachico horns.
I am also here to ask if anybody has considered or designed an asymmetrical twin path horn like these to where the dips and valleys of one path offset that of the other. It seems to me these dips occur probably near the transition of one cross section/length to the next as the horn unfolds. I am not sure exactly why the dips occur but it would seem to me that if one could design a horn with dips and peaks in a specific place on the freq response curve then another could be designed with the dips and peaks in other places on the curve.
My ultimate question is how would one model it to overlap 2 horns where there is cancellation of these effects. What I would love to do is get some pointers from a knowledgeable person here who could help me design something like this. Specifically, I want to build the Sachicko, at least 1/2 of it, and have somebody give me some estimates of what the other 1/2 might look like. I was thinking of just a trial by error shot at this by building it with one 1/2 exactly as in the plans and then build the other 1/2 scaled a little bit up or down, maybe 15-20%. What I am afraid of though is if I get the scale off too much where I actually place the dips and peaks of one 1/2 right on top of the other 1/2.
Is there a rule of thumb on figuring out what aspects of the horn cause the specific dip? If somebody here where to do what I am contemplating (scaling 1/2 different) what % would you try?
Am I making any sense?
Thanks guys (and possibly gals),
Jeff Miller
Lawton, USA
I am fairly new to high sensitivity horn style speakers, esp these rear loaded horn types. I have been building tube gear for some time now but generally the higher powered PP types of amps. I have recently taken an interest in the DHT / SET low powered designs and am in the process of sourcing parts for a build of the Wilson MK1 300B. I know that this new direction is going to require some different speakers with higher sens. than my current Proac 2.5s and Polk M10 speakers. Because of this I am also planning on building a speaker based on the Fostex 206 series driver. I have been hunting for the "perfect" DIY enclosure but have some serious concerns about the frequency response dips I see inherent in the rear loaded horn designs. The Frugal-Horn website has a perfect case in point. The Sachico has wonderful reviews but I can honestly say that I am skeptical given the response graphs that are shown (Here: http://homepage.mac.com/tlinespeakers/FH/images/Sachico-modeled-FR.gif ).
These are some pretty nasty dips that I would find totally unacceptable in the modeling of any 2 or 3 way design I have built or would build. But the reviews.....what about the reviews? They all claim the wondrous sound of these designs.
Well, based on my concerns I am here for some more subjective (and possibly objective) reviews of these speakers....particularly these Sachico horns.
I am also here to ask if anybody has considered or designed an asymmetrical twin path horn like these to where the dips and valleys of one path offset that of the other. It seems to me these dips occur probably near the transition of one cross section/length to the next as the horn unfolds. I am not sure exactly why the dips occur but it would seem to me that if one could design a horn with dips and peaks in a specific place on the freq response curve then another could be designed with the dips and peaks in other places on the curve.
My ultimate question is how would one model it to overlap 2 horns where there is cancellation of these effects. What I would love to do is get some pointers from a knowledgeable person here who could help me design something like this. Specifically, I want to build the Sachicko, at least 1/2 of it, and have somebody give me some estimates of what the other 1/2 might look like. I was thinking of just a trial by error shot at this by building it with one 1/2 exactly as in the plans and then build the other 1/2 scaled a little bit up or down, maybe 15-20%. What I am afraid of though is if I get the scale off too much where I actually place the dips and peaks of one 1/2 right on top of the other 1/2.
Is there a rule of thumb on figuring out what aspects of the horn cause the specific dip? If somebody here where to do what I am contemplating (scaling 1/2 different) what % would you try?
Am I making any sense?
Thanks guys (and possibly gals),
Jeff Miller
Lawton, USA
Attachments
Jeff,
One of the reasons we are slowly pulling the sims out of the frugal-horn docs is that they are often misunderstood.
In practise those dips are not there. there might be a hint of the 1st big one, but the others dissappear in reality.
There are a couple reasons for this.
1/ the simulation software gets less accurate as the frequencies go up.
2/ when these models were made the sim sw did not take into account the room boundaries (Have a look at any of the BIB sims to see how bad things can sim as far as ripple goes)
3/ this sim was done based on a continually expanding line and does not take into account all of the 'bumps" in the expansion that takes place at every fold. Each one of these acts as a low pass filter (8 of them) which stack together to dramatically curtail HF coming out of the horn mouths. It is the HF combing with the front driver in the sim that causes the ripple.
dave
One of the reasons we are slowly pulling the sims out of the frugal-horn docs is that they are often misunderstood.
In practise those dips are not there. there might be a hint of the 1st big one, but the others dissappear in reality.
There are a couple reasons for this.
1/ the simulation software gets less accurate as the frequencies go up.
2/ when these models were made the sim sw did not take into account the room boundaries (Have a look at any of the BIB sims to see how bad things can sim as far as ripple goes)
3/ this sim was done based on a continually expanding line and does not take into account all of the 'bumps" in the expansion that takes place at every fold. Each one of these acts as a low pass filter (8 of them) which stack together to dramatically curtail HF coming out of the horn mouths. It is the HF combing with the front driver in the sim that causes the ripple.
dave
So, are there any real time measurements from a mic showing the actual curve anywhere. I did not realize this was a simulation generated curve, I thought it was measured. Where might I see some measurements taken from a similar design.
So, what exactly is the sim simulating, the response at the mouth of the horn or the wave at the front of the driver? Or does the sim somehow combine the 2 wavefronts together to create this curve?
The big dip that occurs at about 250Hz, is this the one you are speaking of that is audible? How many dB down is the real life response at 250Hz?
So, what do you think of the Sachico Dave? Have you had the chance to hear it? Is it really as fantastic as everyone claims it is?
I have access to a CNC in my town of Lawton and was thinking of actually making several sets of these for myself, friends, and family. My cost for set up is $225 then $15 a board, not including material.
I am planning to spend the $125 anyway so, if there is any interest in having some flat packs of the parts for these speakers, I have already spoken with the owner of the CNC and he will be willing to cut and ship some of these around the USA. I imagine the cost for a pair of these would run around $200 to $225 plus shipping for 3/4" MDF (estimate$35 a sheet x3 + $15 a sheet to cut x3, + Bit replacement fee rounds out to be about $15 a set = $165, add a little extra for sourcing the materials and packaging it up $???).
If anybody reads this and is interested in the above, drop me a message. I am not %100 certain this is the design I will end up doing but I feel pretty good about it. Understand, this is not for any sort of profiteering, just letting people in on some fixed startup costs if they think it is worth it or don't have access to a CNC.
Thanks again for the input, now that I know that was a sim I feel much better about it and don't have such a hard time believing the reviews while looking at those tracings.
So, what exactly is the sim simulating, the response at the mouth of the horn or the wave at the front of the driver? Or does the sim somehow combine the 2 wavefronts together to create this curve?
The big dip that occurs at about 250Hz, is this the one you are speaking of that is audible? How many dB down is the real life response at 250Hz?
So, what do you think of the Sachico Dave? Have you had the chance to hear it? Is it really as fantastic as everyone claims it is?
I have access to a CNC in my town of Lawton and was thinking of actually making several sets of these for myself, friends, and family. My cost for set up is $225 then $15 a board, not including material.
I am planning to spend the $125 anyway so, if there is any interest in having some flat packs of the parts for these speakers, I have already spoken with the owner of the CNC and he will be willing to cut and ship some of these around the USA. I imagine the cost for a pair of these would run around $200 to $225 plus shipping for 3/4" MDF (estimate$35 a sheet x3 + $15 a sheet to cut x3, + Bit replacement fee rounds out to be about $15 a set = $165, add a little extra for sourcing the materials and packaging it up $???).
If anybody reads this and is interested in the above, drop me a message. I am not %100 certain this is the design I will end up doing but I feel pretty good about it. Understand, this is not for any sort of profiteering, just letting people in on some fixed startup costs if they think it is worth it or don't have access to a CNC.
Thanks again for the input, now that I know that was a sim I feel much better about it and don't have such a hard time believing the reviews while looking at those tracings.
I just looked at the Planet HiFI website and had no idea that you guys have already got a flat-pack product for these horns. Please disregard everything I said above, If I go with this design, I will just buy it manufactured. Looking at the prices there it seems it will be more affordable for me to do it that route. I didn't see specifically that the Sachico was offered there but I thought I saw something referencing CAD design so I am sure they could do it. I will investigate further. Thanks again.
Jeff
Jeff
Again, making these out of MDF is a waste of time, money, and results. The cabinets were designed expressly for plywood, and you will not achieve what they are capable of using MDF.
If this gets beyond a few pairs you will need to factor in the cost of a commercial licence to the MJK software.
I would encourage you to proceed, but do it right, and don't undercharge. There are lots of gotchas, and don't underestimate the cost & time involved of packaging a flat pack that will be in excess of 6' long.
dave
Somehow i lost the 1st half of my reply... let's try again.
I have not seen any valid measurements for these... to do so, one needs to have the measure mic in the farfield (3 or 4m) and to have any chance of not measuring the room instead of the speaker, that means humping one of these to a big, quiet, flat parking lot with no obstructions.
The sim is of the system. The sims do also give driver alone and mouths alone. The software, at the time, did not account for many details, and did not consider that the horn is bifricated. The designer (Scott in this case) to interpret what is real & what is not, and use feedback from previous efforts to craft a final design.
Scott has simmed literally thosands of configurations and has feeback from at least dozens of real world builds to guide him.
I have yet to hear a pair so can't speak from personal experience. I do have a set of personal FE206eN set aside for some.
Reports from the field have been almost universally positive. People are sure enjoying them. This is one thread, a search here will find many more.
Further, the response of a speaker in the range of that 1st dip is dominated by floor bounce, so things are much complicated.
I would encourage this, but do be aware that more than a couple sets for friends and family take you to a point where it would be considered commercial and you would need to comply with the use of design terms.
From inquires i know there is demand for a US source of flat-paks. The size of these makes shipping & packaging concerns significant and not having to cross borders greatly simplifies things.
I question $15/board. That implies MDF (which from 20/20 hindsight was your intent). Using MDF for these is a waste. IMO you'd save a lot of money just burning the sheets of MDF before spending the effort to machine & assemble them. You will not get a Sachiko if made with MDF (just something that looks like one)
You want to use a good multiply (the more plys the better). I would expect sheets of Applyply or similar to cost >$100/sheet. It could be made from BB, but that would need some effort to deal with the 60"x60" sheets, likely best to laminate the sides up out of 5 pieces of 12 or 15mm.
dave
I have not seen any valid measurements for these... to do so, one needs to have the measure mic in the farfield (3 or 4m) and to have any chance of not measuring the room instead of the speaker, that means humping one of these to a big, quiet, flat parking lot with no obstructions.
The sim is of the system. The sims do also give driver alone and mouths alone. The software, at the time, did not account for many details, and did not consider that the horn is bifricated. The designer (Scott in this case) to interpret what is real & what is not, and use feedback from previous efforts to craft a final design.
Scott has simmed literally thosands of configurations and has feeback from at least dozens of real world builds to guide him.
I have yet to hear a pair so can't speak from personal experience. I do have a set of personal FE206eN set aside for some.
Reports from the field have been almost universally positive. People are sure enjoying them. This is one thread, a search here will find many more.
Further, the response of a speaker in the range of that 1st dip is dominated by floor bounce, so things are much complicated.
I would encourage this, but do be aware that more than a couple sets for friends and family take you to a point where it would be considered commercial and you would need to comply with the use of design terms.
From inquires i know there is demand for a US source of flat-paks. The size of these makes shipping & packaging concerns significant and not having to cross borders greatly simplifies things.
I question $15/board. That implies MDF (which from 20/20 hindsight was your intent). Using MDF for these is a waste. IMO you'd save a lot of money just burning the sheets of MDF before spending the effort to machine & assemble them. You will not get a Sachiko if made with MDF (just something that looks like one)
You want to use a good multiply (the more plys the better). I would expect sheets of Applyply or similar to cost >$100/sheet. It could be made from BB, but that would need some effort to deal with the 60"x60" sheets, likely best to laminate the sides up out of 5 pieces of 12 or 15mm.
dave
Sachiko is not on the list of flat-pak products we do. If asked we would do one for local pickup, but my experience tells me that prep for shipment alone would add something like $200 to the cost. Packing & shipping 15 pair of Frugel-Horn flat-paks was a real eye opener.
We try really hard to keep anything we ship, below 30 kg and under 1m in length.
dave
I like Baltic Birch. The designs at Fugal Horn actually recommend MDF?!?! This is why I was going to go with MDF, to stay true to the original. If you say otherwise and think ply is better then by all means I will use ply. I had actually given alot of considerateion on how to get a 6ft speaker enclosure out of 5ft square pieces of BB ply...I was going to do this until I read the build sheets a little closer and saw the MDF rec.
With BB I was essetially going to make x2 3ft sections (top and bottom) and splice them together with an external 2ft splicing sheet overlapping 1ft on the top and bottom. I think there is enough square footage to build a pair with 3 sheets if cut properly. I can get BB ply here for about $55 a sheet. I was also thinking of making the internal pieces out of a lower grade ply where they are very short squatty pieces. I wasnt going to buid the stepped taper at the mouth either, just an angled piece. What about using MDF for the first 2-3 turns inside the horn right behind the driver. I would think here the good sonic qualities of MDF might come in handy (ie low resonance).
Well I appreciate the advice about the marketing of these flat packs but I really don't have the desire or time to do this for profit. I was originally just offering cause I figured only the hardcore would find this thread and few people would take me up on the offer....maybe I am wrong.
I am glad to hear that there is no real issue with those graphs in terms of the final sound quality. It makes me want to build them all the more. I am going to plan on building a pair as a prototype using the split design I mentioned spliced in the middle with x2 3ft sections "stacked" together. You aren't joking about the price of high grade ply at 3/4" 8x4 sheets, I recently priced them....from $85 for a decent grade to $130 for a single faced finish grade.
If a person wanted to add a super tweeter to one of these, where exactly would you suggest putting it? Clearly not up on top!
I have to admit that I was kind of excited to try doing what I originally intended by changing the top horns "wave guide" dimensions a little from the bottom to try and offset those peaks and dips. I wonder if there would be any benefit at all from trying to design something like this? Just curious still.
Thanks for the time you spent on your reply, it was well received.
Sincerely,
Jeff
With BB I was essetially going to make x2 3ft sections (top and bottom) and splice them together with an external 2ft splicing sheet overlapping 1ft on the top and bottom. I think there is enough square footage to build a pair with 3 sheets if cut properly. I can get BB ply here for about $55 a sheet. I was also thinking of making the internal pieces out of a lower grade ply where they are very short squatty pieces. I wasnt going to buid the stepped taper at the mouth either, just an angled piece. What about using MDF for the first 2-3 turns inside the horn right behind the driver. I would think here the good sonic qualities of MDF might come in handy (ie low resonance).
Well I appreciate the advice about the marketing of these flat packs but I really don't have the desire or time to do this for profit. I was originally just offering cause I figured only the hardcore would find this thread and few people would take me up on the offer....maybe I am wrong.
I am glad to hear that there is no real issue with those graphs in terms of the final sound quality. It makes me want to build them all the more. I am going to plan on building a pair as a prototype using the split design I mentioned spliced in the middle with x2 3ft sections "stacked" together. You aren't joking about the price of high grade ply at 3/4" 8x4 sheets, I recently priced them....from $85 for a decent grade to $130 for a single faced finish grade.
If a person wanted to add a super tweeter to one of these, where exactly would you suggest putting it? Clearly not up on top!
I have to admit that I was kind of excited to try doing what I originally intended by changing the top horns "wave guide" dimensions a little from the bottom to try and offset those peaks and dips. I wonder if there would be any benefit at all from trying to design something like this? Just curious still.
Thanks for the time you spent on your reply, it was well received.
Sincerely,
Jeff
Definitly not.
If there is any hint of that anywhere it needs to be expiunged.
dave
i'm doing the two 6' sides with a maple ply from home depot, nice quality ply @~$68 4'x8'. the birch ply from lowes (~$48 4x8), isn't too bad either if selective, going to a few different stores to find the best. i'll use 5x5 baltic birch for everything else and eliminate the steps so the diagonal piece at each end makes up for the extra foot of the back panel 6" up and down at each end.
anyway, thats the plan for the Hiro i'm building. it'll only work in the living room so i decided to build two different horns and decide which i like best. it's nice that they can be used with other 6.5" drivers if i decide to trade or sell the cabinets. they're my next project after the ongoing demolition and rebuild of the master bedroom bathroom is completed.
anyway, thats the plan for the Hiro i'm building. it'll only work in the living room so i decided to build two different horns and decide which i like best. it's nice that they can be used with other 6.5" drivers if i decide to trade or sell the cabinets. they're my next project after the ongoing demolition and rebuild of the master bedroom bathroom is completed.
There is a reference to MDF/HDF in the Sachiko docs... paraphrasing "it would not be a hardship to use an alternate naterial for the stepped deflectors"
This is the highest pressure part of the horn, and requires the stiffest material. If you were forced to use 2 qualities of ply, this is where you would use your best stuff.
purely myth those sonic qualities.
That was one of the topics discussed in the Audio Talk thread i linked,
I would expect it to make things worse, but i'm not really qualified to answer.
dave
I don't quite get what you mean Mr Fish... better plywood usually has more ply, less voids. We are looking for stiff, and well damped (more imedance changes at the glue junctions of the layers does that). The goal is to get all the panel resonances (because there will always be some) high in frequency, and high in Q, so that they are much less likely to get excited, and if they do, less likely to be heard.
I know that the trees for Baltic Birch are usually harvested in the winter, because when it is a mild winter the price goes up becuause it is harder to harvest.
Speaking of that, Jeff i should mention that once you are spending the big bucks for veneered appleply kind of stuff, you might as well look at bamboo plywood too. A bit tricky to work & expensive but makes a great speaker.
dave
I know that the trees for Baltic Birch are usually harvested in the winter, because when it is a mild winter the price goes up becuause it is harder to harvest.
Speaking of that, Jeff i should mention that once you are spending the big bucks for veneered appleply kind of stuff, you might as well look at bamboo plywood too. A bit tricky to work & expensive but makes a great speaker.
dave
I have both the Saburo and Sachiko in my listening room. I like the Saburo's Fostex 126EN midrange and highs better. The Sachiko's bass is bigger and deeper, but my ears and brain don't process the highs coming from those whizzer's as being very natural. Sometimes more sibilant than the 126E. I'm sure many would probably disagree, but there are also a lot of threads about ways to overcome the 206E peaky nature, so it is well documented that it exists. I have the Planet 10 phase plugs, which made them tons better and definitely listenable long term, but I still find the highs from the 126E more pleasing. If you need lots of bass though for rock, electronica, etc., Sachiko will give it to you. Just my 2 cents since you haven't put the blade to the wood yet.
I might be posting a "shoot out" review between the Mikasa, Saburo and Sachiko in the coming weeks. I will have multiple listeners to evaluate so there isn't single brain bias.
I might be posting a "shoot out" review between the Mikasa, Saburo and Sachiko in the coming weeks. I will have multiple listeners to evaluate so there isn't single brain bias.
You don't quite get about Guarneri's "the cannon"?
I have built three of the designs from Planet10 site for fe 127e's fonken, brynn,Olivia all very nice sounding so, just scepticism Mr Planet
I guess that it is very clear all birch trees grow in different conditions Baltic region, Russia, Kamchatka, Canada,different glue used,dif technological process , HomeD birch ply differs from BB ply so that all birch plywood has different characteristics. but, if it claims that something is designed for something .....
they always do the streets in winter for the same reason labor cost more
I have built three of the designs from Planet10 site for fe 127e's fonken, brynn,Olivia all very nice sounding so, just scepticism Mr Planet
I guess that it is very clear all birch trees grow in different conditions Baltic region, Russia, Kamchatka, Canada,different glue used,dif technological process , HomeD birch ply differs from BB ply so that all birch plywood has different characteristics. but, if it claims that something is designed for something .....
There is no question that there are differences in plywoods. We tried some russian 4x8 birch ply, it wasn't as good as the true 5x5 baltic birch which is what we mostly use, but still way ahead of MDF. Things like the premium Appleply are, i suspect, a bit better than BB, but also about 2x as much $$. If we have to spend the extra, we so far have jumped up to bamboo ply, which is a step up. I haven't found any Canadian birch ply, but i know there is poplar ply. If i could find some with close to as many plys as BB we'd try that. A locally made spruce plywood with as many or more plys than BB might be the holy grail (but i can't afford to buy one of the plywood factories here)
The keys are stiffness and damping. That usually means more plys.
dave
The keys are stiffness and damping. That usually means more plys.
dave
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