Hi,
Not to put too fine a point on it, a conjectural build that has many problems,
apparent or otherwise, it not a good choice with other options available.
There are lots of issues with a 2 x10" MTM with metal coned bass/mids
and a planar 8" tall tweeter you haven't discussed above, and you can't
simply knock up an on paper c/o you think will work, it needs modelling.
The tweeter has a whopping peak at 10KHz and very poor vertical
directivity. The low slope high pass is an invitation for poor distortion
and out of band response due to the metal drivers huge peak. It
will also guarantee very poor vertical lobing of the MTM layout.
I could go on with quite a few other points, but its pointless .....
rgds, sreten.
I realize everyone will suggest a proven build, and I have to agree that doing so is definitely the smartest if you don't want problems. However, the way I see it is... if you are building custom, why not venture out and try a configuration that hasn't been tried? Way I see it, when you build something that has been built before, you don't have something unique. I think that half of the enjoyment of building a custom speaker, is knowing that you have something that has never been done before (at least, in that precise configuration). In my experience, if you build based on some reasonable premises (matching driver efficiency, calculated crossovers, decent box construction) you are guaranteed a speaker that works reasonably well, and more often than not, they work very respectably well.
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Hello sreten,
I believe the 700hz crossover point will reduce a lot of the issues with the large driver size and separation. Perhaps I am wrong.
I believe that elevating the speakers such that the planar is roughly centered to average listening height will solve the vertical dispersion issues well enough.
I believe that my later suggested 12db/octave slope on the low pass (after finding that the Neo8 gains on the bottom end with baffle loading) will solve the "peaky" aluminum cone issue well enough.
The on-axis peaking above 10K is a tradeoff of trying to make this a 2-way system. If it were bothersome this could be notched out with a filter or EQed out easily enough.
Keep in mind here, I'm trying to come up with the best that I can come up with given the budget, that, as far as I know, has never been done.
Eric
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Hello sreten,
I believe the 700hz crossover point will reduce a lot of the issues with the large driver size and separation. Perhaps I am wrong.
I believe that elevating the speakers such that the planar is roughly centered to average listening height will solve the vertical dispersion issues well enough.
I believe that my later suggested 12db/octave slope on the low pass (after finding that the Neo8 gains on the bottom end with baffle loading) will solve the "peaky" aluminum cone issue well enough.
The on-axis peaking above 10K is a tradeoff of trying to make this a 2-way system. If it were bothersome this could be notched out with a filter or EQed out easily enough.
Keep in mind here, I'm trying to come up with the best that I can come up with given the budget, that, as far as I know, has never been done.
Eric
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Hi,
If. Your reasonable premises are only yours and are full of holes.
There is nothing good about a half-baked "custom" build.
The classic first time builders mistake.
rgds, sreten.
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I would suggest that if the thread starter wants it or is uncertain or is looking for a head start. I got by for almost thirty years in the hobby with only a few books to keep me company and I'd be happy to start a newcomer at any level they'd ask for.
In the end, some of the mids/treble, much of the upper bass/lower mids, and most of the bass has significant room dependency. A speaker can be designed to have an effect on this, and therefore some will be doomed from the start, but how many speaker project pages include reasonable instructions for setting up your room? How many give you the intended listening axis? In such cases it will have to be DIY or the speakers will not sound more than 'good'.
Ok I am going to show this all to my dad since he is the one who went to college for electrical engineering and this is all way over my head. I don't think he is set on the dual 10" woofers it's just something we were discussing one day so I thought I would as here about it. I just want something that is going to sound as good as possible on a tight budget and we don't have all the crazy wood working tools so it has to be something simple we really just want to build a couple simple cabinets that will take 100wrms @ 8 ohms or 150wrms @ 4 ohms each. My family all got together to order him a 15" sub and plate amp so we already have those and are going to build a box for that soon so that is part of the system. He was wanting to make a couple 3 ways with the woofers over lapping the subs since that's what he has always had, but we are more then willing to try something new but it sounds to me like a proven design is the way to go since we will know a head of time that it will sound good. I am going to have my dad read all this and see what he thinks then I will hopefully post with our decision. Some of you thought I was arguing with you or something and I'm not sure why you thought that but I appreciate all your guys help and opinions so don't think that they are in vein.
My dad has some boxes he is using now that maybe we could use for the 3 ways. 2 are for 8" woofers and are around 0.88cuft and the others are pretty large they are around 8.31cuft, The large ones would probably be perfect for those 2 10" aluminum daytons since their VAS was around 3.8cuft each. They do have some fill inside on each wall and I'm not sure if they have crossovers yet. Here is a picture of what he has atm. Sorry the pic is so blurry.
That 200 HZ is the problem.
When I think of subwoofers, I think of the octaves below 80hz.
Personally I see nothing fundamentally wrong with using a 15inch subwoofer with 10inch midbass units, just getting the integration right can be a problem and a lot depends on whether the midbass are in sealed boxes or ported.
Adding a sub in parallel below 80 has been suggested and that is what I would be doing if I wanted to keep things simple.
When I think of subwoofers, I think of the octaves below 80hz.
Personally I see nothing fundamentally wrong with using a 15inch subwoofer with 10inch midbass units, just getting the integration right can be a problem and a lot depends on whether the midbass are in sealed boxes or ported.
Adding a sub in parallel below 80 has been suggested and that is what I would be doing if I wanted to keep things simple.
Yea I would be setting the crossover on the sub at 80-100hz and probably cut the lows out of the mid bass (woofers) at 100hz and below so the sub will take over the lows from there. I'm not sure what you mean by "integration" exactly. So far I am liking the idea of using the 2 10's in the current 8.3cuft boxes my dad has because it would be easier and we wouldn't have to buy any wood. They would be ported I'm just not sure what to tune the port to on a 3 way since I've only made sub boxes. Would I have to seperate the 2 woofers? I've seen people go both ways obviously I'd prefer not since it would be less work. My dad says the large boxes are still solid so I'm all for using them over completely starting from scratch and because he wants to put them together gradually since he doesn't have the extra money to get all the new drivers at once.
We were wondering about the 3 way off the shelve crossovers I linked in the first post do they cut the low end from 100hz and below from the woofers? It doesn't say they do but I would like to do that so everything below is just handled by the sub. Could we just put a high pass crossover between the woofers and the main 3 way crossover? This one here 100 Hz High Pass 4 Ohm Crossover 266-460
Why are generic ones bad? They cut off at all the frequencies that I would use and are 12db/octive they look nice to me?
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Absolutely fine. There is no need to high pass your mains, and you probably shouldn't. There is also no problem with using your sub around 200Hz if there is a requirement for it.
I am going to set the sub crossover to 100hz and the woofers in the 3 ways can take over from there. I did want to cut anything below 100hz on the 2 way woofers just so I didn't have that extra excursion going to them wouldn't it help a little bit? I still don't get what is wrong with generic crossovers?
Two 10" woofers, if enclosed properly, will play quite loud before hitting the stops. When you plan to overlap with subs, the box you use can be a sensible sized closed one rather than trying to get every last bit of extension to the response at the expense of cone excursion.
As far as generic crossovers are concerned, there are four primary concerns: level setting, impedance interaction, response matching and phase matching. I can help you through these but it's not a small subject so I'll wait until you ask.
Sometimes you can luck out and a generic crossover will almost work well as is, most of the time it is not so good.
As far as generic crossovers are concerned, there are four primary concerns: level setting, impedance interaction, response matching and phase matching. I can help you through these but it's not a small subject so I'll wait until you ask.
Sometimes you can luck out and a generic crossover will almost work well as is, most of the time it is not so good.
The problem I see with the sub being integrated into this WITH a high pass in place on the mains is the terrible allocation of resources. I'm sure others are seeing the same issue- it's just a waste.
Using 4x10" drivers as "midrange" units, and then crossing them over to a single 15" is insulting to the capability of all those 10" drivers. You'd have 60% more driver surface area being used for mid-range than for bass, which makes no sense at all. Your bottom range requires the most surface area. When you build "mains" that are using 4x10" drivers for mids, then a properly matched sub system would look more like 4x18" drivers or bigger. I've seen studio monitor configurations that use a single 8" as the mid range driver, and pair that up with a 21" sub for the lows. (That's a 21" driver for each side!)
The simulation I posted in my build idea there shows what happens if you leave your 10" drivers to carry the lows without any high pass under maximum drive levels... As you can see, you have "mains" that are far more capable than the sub through the bass range. So at that point, the sub seems almost unnecessary. In fact the sub is really doing nothing more than some mild supplementing. I think I would have skipped it all together if I were building mains with so much driver surface area.
Using 4x10" drivers as "midrange" units, and then crossing them over to a single 15" is insulting to the capability of all those 10" drivers. You'd have 60% more driver surface area being used for mid-range than for bass, which makes no sense at all. Your bottom range requires the most surface area. When you build "mains" that are using 4x10" drivers for mids, then a properly matched sub system would look more like 4x18" drivers or bigger. I've seen studio monitor configurations that use a single 8" as the mid range driver, and pair that up with a 21" sub for the lows. (That's a 21" driver for each side!)
The simulation I posted in my build idea there shows what happens if you leave your 10" drivers to carry the lows without any high pass under maximum drive levels... As you can see, you have "mains" that are far more capable than the sub through the bass range. So at that point, the sub seems almost unnecessary. In fact the sub is really doing nothing more than some mild supplementing. I think I would have skipped it all together if I were building mains with so much driver surface area.
mdocod, what you say is logical, but can't the question just be: "How much sub do you need?". A few 10" or 12" subs or something equivalent is all most people will need. For my room, beyond that and the benefits do not outweigh the inconvenience of the space they use.
On the other hand, a mid could be larger for a few good reasons. My mids are larger than my subs put together. It gives me directivity, efficiency, and it keeps the voice coil cool.
So your saying that I should just go with smaller mid-bass because the sub is going to handle most of it? I have run the idea by my dad about just running smaller mid-bass he isn't apposed to it but one of the ideas was to use the large boxes we already have. Would it sound really bad if I just had the 10's overlap the 15" sub?
I wasn't planning on using the 10's as mid-range I'm using a 6.5 or 5" for mid-range the 10's are for midbass from 100hz to around 5-700hz I was planning to use them for the bass that the sub cannot hit. Now that I think about it they do go up to around 6,000hz I could maybe skip the mid-range and just run the 10's and a tweeter as a 2-way?
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Hi,
Because they are wrong. You've pretty much had all the good advice
your going to get, everything else is discussing pointless mediocrity.
If you want to build some impressive looking big speakers that are
at best mediocre, and unsuitable for purpose carry on regardless.
If you want the best sound that goes loud for ~ $400 build
the Tarkus, and don't discuss the crossover to subs until
you know what your actually practically dealing with.
If nevertheless you intend to c/o at 100Hz, this thread is nonsense.
rgds, sreten.
Quality done right always surpasses impressive looking mediocrity.
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Hey, Ninesvnsicks! How's it going?My dad has some boxes he is using now that maybe we could use for the 3 ways. 2 are for 8" woofers and are around 0.88cuft and the others are pretty large they are around 8.31cuft, The large ones would probably be perfect for those 2 10" aluminum daytons since their VAS was around 3.8cuft each. They do have some fill inside on each wall and I'm not sure if they have crossovers yet. Here is a picture of what he has atm. Sorry the pic is so blurry.
This is his what we were waiting for, a picture, so we know what you are after. Congratulations for the "karate-kid" on top of the speakers. First, I don't want to harass you or the thread but it seems that you're finally on the right path and as always given very good knowledge. Electrical engineers always come here for acoustics...
Now, on the speakers, I think and that's valid for me until now, that the best thing in design, is to choose the mid driver or mid frequencies driver and from there designing the speakers. You are doing just the opposite, starting with subs. I understand you have the boxes, that can be good... but is your faith. Now, you have boxes and want a metal cones drivers. Now, those drivers are not so good for 2-Ways that I know, so usually they need 3-Ways (plus sub, that's a lot for 300,00 USD only). And you don't know what you are doing for mids... this is the most important frequency band from 300's Hz to 3000 KHz (note: more or less), meaning you have an all speaker project to do and next year you are still debating if you want the subs, the 2x10" metal cones or new ones, da-da da-da... and spending more than in McIntosh's. You don't know, from what I understand to this post, if you go the 3-Way V 2-Way route. You can choose your speakers/drivers following a pattern or design and I just don't know, after a few days, what that pattern is. I just see a set of nice boxes setting there on the floor, probably working OK and nothing else (your father was right, he is an engineer... at least he is enjoying and you don't). I am going to give you another web-link of a classic US diy speaker maker so that at least if you need a driver or complete set-up that was well experimented and works very fine you can (look, learn or buy and) follow your route. 
Pi Speakers - unmatched quality and state-of-the-art performance
Now, and finally what's this about? Look at this picture, and visualize if you want a 2-Way or 3-Way, now see there is a description of the drivers for one and for the other, that's the way to go. If you want my opinion, buy a kit (with crossover) and maybe that's your route for you and your father for next couple of years, or follow the very nice ideas given in this thread only for you, you choose. (But) You have to visualize the end of the action just like in Karate...
Attachments
My dad teaches T'ai Chi so those are his pictures
My dad only made it to the 2nd page of this thread before giving up on reading it lol. So far the best design for the money I have seen is the tarkus so I'm leaning toward that design atm. I was just trying to do the simplest design and was thinking I could use any of the boxes he currently has but it looks like I can't because the dual driver or a driver that would use a box that big wouldn't sound good.
My family wanted to get him something for christmas so we all chipped in on a sub amp and sub because it's what we could afford to do my dad is the one buying the parts for the 3-ways and they will be $400 or more so we did what we could afford and he wanted a 15" subwoofer so that is what we went with, you guys all think that the sub will sound bad? I'm trying to build around that so please stop yelling at me I came here for help because I don't know what I am doing and I heard this is a good place to ask questions. When you tell me something is wrong I just want to know why they are wrong so I can start to learn. I didn't think it would be this complicated to build a couple of 3 way speakers.
We are not rich and have a budget of around $400 so the tarkus is the only design I have seen that stays within that budget and doesn't require a physics major to put together lol. I didn't know the drivers I picked in the beginning were so bad that is why I come here to find out. So from what I see I have to make my own crossovers because the off the shelf ones wont give me the right levels and impedance, the only problem with that is I don't know how to make them.
Can someone help me pick out some nice woofer, mid and tweeters and maybe make me a diagram for making the crossovers that would work with them. I think my dad could read a diagram and put them together. Idk if that is asking too much if it is that is ok and I'll try my best with the tarkus design since there's a build log.
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