Hello,
I am in need of an advice and well, I also admit that I have shot first and too fast before even properly asking a question in my impatience.
I started to look up some speaker builds perhaps a month ago and soon started to choose components and their value just on paper.
When I was done, I have decided to order caps and inductors in advance because, what could go wrong right? And so today when time has come to also order speakers for my build I have decided to revide my speaker pickings and well I have made a mistake in choosing wrong frequency cut in my crossover my first thought have been to cut it at 4500Hz but after revision I have come to conclusion that it would be too much for an woofer that I have chosen next thing was that tweeter I have picked was already sold out too and I have had to choose another one with little different specs and my next best guess is that crossover cut should be done at 3500Hz which is a recommended cut by my new tweeter manufacturer. Tweeter is Monacor MHD-152 and I would like to pair it with Eminence Alpha-8A so now I have caps and inductors that does not posses adequate specs to make a lower cut.
So my question is. Can I put additional smaller value caps in partallel to originals and inductors in series to original ones to make up for difference in values that I need now? Or should I just buy correct values?
And also I would be happy to hear opinions on this pairing, do you thing I should choose different speakers for this build?
Thank you for answers. I have also added a schematic of my crossover with smaller value components accounted for please take a look if it is correctly put together I am also adding up spec sheets for both speakers.
Cheers!
I am in need of an advice and well, I also admit that I have shot first and too fast before even properly asking a question in my impatience.
I started to look up some speaker builds perhaps a month ago and soon started to choose components and their value just on paper.
When I was done, I have decided to order caps and inductors in advance because, what could go wrong right? And so today when time has come to also order speakers for my build I have decided to revide my speaker pickings and well I have made a mistake in choosing wrong frequency cut in my crossover my first thought have been to cut it at 4500Hz but after revision I have come to conclusion that it would be too much for an woofer that I have chosen next thing was that tweeter I have picked was already sold out too and I have had to choose another one with little different specs and my next best guess is that crossover cut should be done at 3500Hz which is a recommended cut by my new tweeter manufacturer. Tweeter is Monacor MHD-152 and I would like to pair it with Eminence Alpha-8A so now I have caps and inductors that does not posses adequate specs to make a lower cut.
So my question is. Can I put additional smaller value caps in partallel to originals and inductors in series to original ones to make up for difference in values that I need now? Or should I just buy correct values?
And also I would be happy to hear opinions on this pairing, do you thing I should choose different speakers for this build?
Thank you for answers. I have also added a schematic of my crossover with smaller value components accounted for please take a look if it is correctly put together I am also adding up spec sheets for both speakers.
Cheers!
Attachments
I like to have many values to work with. Sometimes this means doing exactly what you suggest. From time to time I'll clean things up and use preferred ways of getting the values I need but while working toward these values, things might get a little messy.
The cost of buying new components is unlikely to be much different from buying 'patch up' ones.
Since you are a beginner, this is probably the more efficient way to go, and will help avoid mistakes.
You appear to have chosen the drivers more or less at random and this is unlikley to result in a satisfactory combination.
You also make no mention of the size or design of your intended enclosure, so are asking someone to do all the design work for you.
The usual advice given to beginners to loudspeaker building is to follow a set of published plans or to buy a kit.
Well, actually I have a design in mind, that is an simple almost a cube 35x35x25cm which is about 1 cu. ft. or about 28 liters sealed box made of MDF board with outer shell made of pinewood. This should have enough space to accomodate speaker cones, crossover and reinforcements and still have enough room to allow air to be moved. But to tell the truth I really don´t know much about how to calculate it properly, but since I am half way through already, there is no way back and I want to try to finish it, maybe it will be last speaker, maybe not I just know that it would make me very happy, even if sound would not be the greatest.
And speakers are not chosen randomly, it is true, that I don't know how to pair them properly, as an exemple I have chosen Eminence speaker because I like the brand not just that it is made in USA but also what Eminence company stands for that even when manufacturing costs in USA are high they would not abbandon it and won't move to China or any other cheap labor country, on the other hand tweeter has been picked a little at random I realy wasn't sure how to pick the right one, that is until I stumbled apon Monacor one it had pretty nice horn made of cast aluminium, that soudned great at it had recommended crossover frequency more suited to be paired with Eminence speaker.
Well and that is probably the whole missing part of the story.
But still thank you guys for your insight I have decided I would buy correct capacitor value it is not realy much of a price difference, but with coils on the other hand I will stick with additional smaller value ones it is about 10 bucks per coil more if I would have to buy correct value one and I would feel like I have wasted the others that I won't be able to use.
Thank you. 🙂
And speakers are not chosen randomly, it is true, that I don't know how to pair them properly, as an exemple I have chosen Eminence speaker because I like the brand not just that it is made in USA but also what Eminence company stands for that even when manufacturing costs in USA are high they would not abbandon it and won't move to China or any other cheap labor country, on the other hand tweeter has been picked a little at random I realy wasn't sure how to pick the right one, that is until I stumbled apon Monacor one it had pretty nice horn made of cast aluminium, that soudned great at it had recommended crossover frequency more suited to be paired with Eminence speaker.
Well and that is probably the whole missing part of the story.
But still thank you guys for your insight I have decided I would buy correct capacitor value it is not realy much of a price difference, but with coils on the other hand I will stick with additional smaller value ones it is about 10 bucks per coil more if I would have to buy correct value one and I would feel like I have wasted the others that I won't be able to use.
Thank you. 🙂
Looking at your crossover schematic, you have the same component values for the woofer as the tweeter, which makes me think you've used the 'nominal' 8 ohms to calculate the values.... please read my sig below, then take your impedance vales from the manufacturer's graphs & re-calculate
These schematics always give the false illusion of being Absolute Truth. Of course, once these crude guesses are concealed inside your speaker box, goooooood.... bye....
Be sure to make R3 a variable 10-Ohm pot or that this resistance remain accessible so you can change it. You'll certainly be adjusting it a few times before you settle on one setting.... temporarily.
I'd say almost the same for every value in the drawing. Well-wrought crossovers have a dozen elements carefully tuned by multiple ears and measurements over the R&D period. Go to DSP.
B.
Be sure to make R3 a variable 10-Ohm pot or that this resistance remain accessible so you can change it. You'll certainly be adjusting it a few times before you settle on one setting.... temporarily.
I'd say almost the same for every value in the drawing. Well-wrought crossovers have a dozen elements carefully tuned by multiple ears and measurements over the R&D period. Go to DSP.
B.
By design, I mean designing an enclosure which matches the electrical and mechanical parameters of the bass/mid driver.
Assuming your near cube has an internal volume of around 0.9 cu ft after allowing for wall thickness, volume occupied by the drivers etc., you will see from the Eminence specification sheet that you require a ported box.
Perhaps someone here will kindly calculate the dimensions of the port (diameter & length) for you in order to ensure a reasonable bass response from your desired enclosure.
Hello again, thank you for more valuable input.
PeteMcK. I did not know that, thank you. I have looked up grafs and for a tweeter impendance would still be at 8 ohm but on woofer it will be pushed to 12 ohm, also I have to mention that I also revised speaker choosing and cabinet size.
I am still with Eminence ALPHA-8A but have choosen driver from Eminence also ASD 1001 + Eminence LH 290 S horn that has recommmended crossover cut at 2500Hz which I think would also benefit to the woofer at those frequencies I have found mentioned above impedance. I will make new schematic for it and will post it here also.
Also I have came up with new dimmension since Eminence horn is a bit bigger that yould be 42x32x25cm that is about 1.1cu.ft. so it is 0.1 bigger then before, also Galu you were right about it beign too big for sealed, but I don't realy know where to make it smaller. So I will have to make it ported, but to tell the truth I have tryed to find some
calculator that helped me came up with port of 2 inch diameter and 6.31 inch lenght, which has counted with 1.0 cu. ft. air space and tuning frequency of 33Hz but if that is correct, I don't know.
I would be really glad if there is anyone else that would help me with port parameters. Thank you.
PeteMcK. I did not know that, thank you. I have looked up grafs and for a tweeter impendance would still be at 8 ohm but on woofer it will be pushed to 12 ohm, also I have to mention that I also revised speaker choosing and cabinet size.
I am still with Eminence ALPHA-8A but have choosen driver from Eminence also ASD 1001 + Eminence LH 290 S horn that has recommmended crossover cut at 2500Hz which I think would also benefit to the woofer at those frequencies I have found mentioned above impedance. I will make new schematic for it and will post it here also.
Also I have came up with new dimmension since Eminence horn is a bit bigger that yould be 42x32x25cm that is about 1.1cu.ft. so it is 0.1 bigger then before, also Galu you were right about it beign too big for sealed, but I don't realy know where to make it smaller. So I will have to make it ported, but to tell the truth I have tryed to find some
calculator that helped me came up with port of 2 inch diameter and 6.31 inch lenght, which has counted with 1.0 cu. ft. air space and tuning frequency of 33Hz but if that is correct, I don't know.
I would be really glad if there is anyone else that would help me with port parameters. Thank you.
Ensure you are using an accurate figure for the effective internal volume of the enclosure, after deducting the volume occupied by the drivers etc. etc.
Could you name, or post a link to, the port calculator that you used?
I suppose having someone else calculate the port dimensions won't increase your knowledge of loudspeaker design.
Better to work your way through the process with some guidance, even if the end result turns out not to be perfect.
Could you name, or post a link to, the port calculator that you used?
I suppose having someone else calculate the port dimensions won't increase your knowledge of loudspeaker design.
Better to work your way through the process with some guidance, even if the end result turns out not to be perfect.
I've used this calculator to get the lenght of the port, but I could not find site where I read about the tuning frequency and diameter.
Port Length Calculator
Port Length Calculator
That is a very simple port calculator which doesn't take into account the T/S parameters of the driver and doesn't allow you to predict the bass performance of the speaker/box combination.
The calculator is really only useful if you tune the port in the traditional way to match the resonant frequency (Fs) of the driver, which in your case is 73Hz.
You really need to do further research on enclosure design. Look to Eminence for this: Understanding Loudspeaker Data | Eminence Speaker
The calculator is really only useful if you tune the port in the traditional way to match the resonant frequency (Fs) of the driver, which in your case is 73Hz.
You really need to do further research on enclosure design. Look to Eminence for this: Understanding Loudspeaker Data | Eminence Speaker
Her's a more effective, but not too complicated calculator: Speaker Box Enclosure Designer / Calculator
I would estimate the effective cone diameter (D) as 7".
You can experiment with different box tuning frequencies (Fb) to find a practical combination of box volume, port dimensions and bass extension (F3).
P.S. The 'Ported Butterworth B4' option gives an enclosure volume close to your desired volume.
You can experiment with different box tuning frequencies (Fb) to find a practical combination of box volume, port dimensions and bass extension (F3).
P.S. The 'Ported Butterworth B4' option gives an enclosure volume close to your desired volume.
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