Hi,
I'm about to start building my first set of speakers. It's a 2-way ported design, I attached the schematic of the crossover.
The value for C3 in the tweeter circuit is 33uf.
I'm having some trouble sourcing the exact capacitor values so my first question is: how precise do I need to be?
Specified is a 4.2 + 10 uf cap and a 1.5 + 4 uf cap.
I'm looking at Audyn Q4 or Jantzen cross (or anything else in that price range) and I can get a 15uf cap, or a 10 + 4.7, or 10 + 3.9 uf.
For the 5.5 value, I can get a 5.6 or a 1.5 + 3.3
Do these differences matter? Should I try to get as close as possible using a couple of caps, or just get the closest value single cap?
Second question is about the adjustable resistor (R1). Why is this a adjustable resistor and how do I determine the value I set it to?
Last question is about the bass port. The design specifies a 64mm x 120mm tube. The closest I can find is 68mm. Will such a difference affect the sound?
Cheers,
Ej
I'm about to start building my first set of speakers. It's a 2-way ported design, I attached the schematic of the crossover.
The value for C3 in the tweeter circuit is 33uf.
I'm having some trouble sourcing the exact capacitor values so my first question is: how precise do I need to be?
Specified is a 4.2 + 10 uf cap and a 1.5 + 4 uf cap.
I'm looking at Audyn Q4 or Jantzen cross (or anything else in that price range) and I can get a 15uf cap, or a 10 + 4.7, or 10 + 3.9 uf.
For the 5.5 value, I can get a 5.6 or a 1.5 + 3.3
Do these differences matter? Should I try to get as close as possible using a couple of caps, or just get the closest value single cap?
Second question is about the adjustable resistor (R1). Why is this a adjustable resistor and how do I determine the value I set it to?
Last question is about the bass port. The design specifies a 64mm x 120mm tube. The closest I can find is 68mm. Will such a difference affect the sound?
Cheers,
Ej
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You would be fine +/- 10% on any of the capacitor values. I would get a single component as close to the value as possible (so 5.6uF in the tweeter would be fine) and either a 14uf or 15uF in the woofer would work.
You did notice the C3 in the tweeter circuit isn't notated with a value? I am assuming that is the DCR from the coil right before it, but not for sure.
You did notice the C3 in the tweeter circuit isn't notated with a value? I am assuming that is the DCR from the coil right before it, but not for sure.
Any decent MKP cap has a tolerance of 5%, so anything can be rounded to the nearest standard value if the difference is less than the tolerance.
So for the 5.5uF cap you will be fine with a 5.6 one, for the 14.2uF cap you can go with a 15uF one, a little borderline but frankly I don't think you can notice the difference.
What bothers me is that a design that calls for a 5.5uF cap has a good degree of probability to be something not designed from a competent person. The same can be said with respect of the variable resistor: a good design should have a set of measures with different values of that resistor, I would buy fixed resistors with values near of what you need (5R0?), and try.
For your quest on the tube, a larger than needed port lowers the air speed (good), but needs to be longer for achieving the same tuning.
Ralf
So for the 5.5uF cap you will be fine with a 5.6 one, for the 14.2uF cap you can go with a 15uF one, a little borderline but frankly I don't think you can notice the difference.
What bothers me is that a design that calls for a 5.5uF cap has a good degree of probability to be something not designed from a competent person. The same can be said with respect of the variable resistor: a good design should have a set of measures with different values of that resistor, I would buy fixed resistors with values near of what you need (5R0?), and try.
For your quest on the tube, a larger than needed port lowers the air speed (good), but needs to be longer for achieving the same tuning.
Ralf
Thanks for the answers.
I found the formula to calculate the bass port length vs diameter so I'll be alright with that.
Can someone explain to me what the purpose of the resistor (R1) is, and how it's value can/should be calculated?
Can the reason for being a adjustable one be so the two crossovers (from both speakers) can be exactly matched or doesn't that make sense?
Ej
I found the formula to calculate the bass port length vs diameter so I'll be alright with that.
Can someone explain to me what the purpose of the resistor (R1) is, and how it's value can/should be calculated?
Can the reason for being a adjustable one be so the two crossovers (from both speakers) can be exactly matched or doesn't that make sense?
Ej
R1 is there to bring down the level of the tweeter, as usually a tweeter is louder than a woofer. To calculate the value of the resistor knowing how many dB you need to pad down requires the knowledge of the Re of the tweeter.
The only reason IMHO for a variable resistor is because not all people like the same HF brightness.
Ralf
The only reason IMHO for a variable resistor is because not all people like the same HF brightness.
Ralf
Hi,
I would seriously question that crossover design.
The tweeter part doesn't make any sense to me.
What are the drivers ?
rgds, sreten.
I would seriously question that crossover design.
The tweeter part doesn't make any sense to me.
What are the drivers ?
rgds, sreten.
Hi,
The schematic is for the Audio Note AN-E speaker.
The schematic is in the manual you can download from the audio note site: http://www.audionote.co.uk/comp/kit_speaker_an-e.pdf
The drivers are the SPKR-002/H and SPKR-031. I do not have the extended specs for them.
What do you think is weird about the schematic?
Ej
The schematic is for the Audio Note AN-E speaker.
The schematic is in the manual you can download from the audio note site: http://www.audionote.co.uk/comp/kit_speaker_an-e.pdf
The drivers are the SPKR-002/H and SPKR-031. I do not have the extended specs for them.
What do you think is weird about the schematic?
Ej
Hi,
The schematic is not in that manual.
The tweeter x/o is first order followed by a very
deep 0.5R notch, presumably set at the tweeters
Fs, a very unusual elliptic approach. As its an
Audionote design I'm not going to comment
further, they should know what they are doing.
rgds, sreten.
FWIW no way do you need 20W for R2 and R3.
The schematic is not in that manual.
The tweeter x/o is first order followed by a very
deep 0.5R notch, presumably set at the tweeters
Fs, a very unusual elliptic approach. As its an
Audionote design I'm not going to comment
further, they should know what they are doing.
rgds, sreten.
FWIW no way do you need 20W for R2 and R3.
What's weird is that AN feels they need to delay the woofer instead
the tweeter. I wonder why they didn't specifiy the listening axis for
optimal listening experience.
Sorry I posted the wrong link to the manual.
You can find it here AUDIO NOTE AN-E/D OWNER'S MANUAL Pdf Download.
I'm sure I got my copy from their site but can't seem to find it anymore.
The same schematic is on Troels Gravesen's site: High Efficiency Speakers
He played around with different versions of the schematic, but his final design is very close to the original.
As I like the sounds of their production models, and the box is one of the easier ones to build, it seems like a good project for me.
Ej
You can find it here AUDIO NOTE AN-E/D OWNER'S MANUAL Pdf Download.
I'm sure I got my copy from their site but can't seem to find it anymore.
The same schematic is on Troels Gravesen's site: High Efficiency Speakers
He played around with different versions of the schematic, but his final design is very close to the original.
As I like the sounds of their production models, and the box is one of the easier ones to build, it seems like a good project for me.
Ej
The tweeter design looks like it is using a congegate load on the tweeter. Its slightly unusual to use it just on the tweeter but presumably this tweeter has a resoanace that was upseting the response. It the uses a smple first order roll off which might be being used in combination with natural roll off to match the second order on the bass. You would need response curves to be sure.
Andy
Andy
Thanks for all the comments and answers.
Actual driver specs are hard (impossible?) to find. Stereophile tested the signature version of the speaker which is, in essence, the same. You can look at some curves here
In one of the other review of a production version found, there are some pics of the crossover (review is in Dutch).
There, they also use the adjustable resistor, so they must have some reason to use it.
They also use electrolytics. Is that just being cheap or can there be other reasons for doing so.
Ej
Actual driver specs are hard (impossible?) to find. Stereophile tested the signature version of the speaker which is, in essence, the same. You can look at some curves here
In one of the other review of a production version found, there are some pics of the crossover (review is in Dutch).
There, they also use the adjustable resistor, so they must have some reason to use it.
They also use electrolytics. Is that just being cheap or can there be other reasons for doing so.
Ej
Having seen the curves I think they are using the tweeter roll off, this would explain the adjustable resistor as using the acoustic roll off of the tweeter will be poorly controlled, hence the need for adjustment presumaby by measurement for each driver.
Where are you getting the drivers from as this design looks like it is highly driver specific so I doubt it will work well with anything but the exact drivers it was designed for.
Regards,
Andrew
Where are you getting the drivers from as this design looks like it is highly driver specific so I doubt it will work well with anything but the exact drivers it was designed for.
Regards,
Andrew
You can get them at various shops, but I'll probably order them from hificollective or a shop here in The Netherlands.
Good to see you can buy them. They seem expensive for what they are, they look like Seas designs presumably modified for Audio Note but it very hard to tell most speaker baskets look very similar.
For the money I would think you could get a better controlled tweeter that didnt need the congugate load but then you would be into designing your own.
The electrolitic caps will be to save cost and possibly space, large value foil caps are big.
If you are spending that sort of money, I recomend buying a measurement microphone, or making one with a capsule and downloading Holm impulse, it will allow you to measure your design and adjust the tweeter as well as confirm you have built it correctly. You only need a computer with a half decent sound card to make quite good measurements above the first reflection time.
It is also the best way to start to understand how frequency response affects sound.
Regards,
Andy
For the money I would think you could get a better controlled tweeter that didnt need the congugate load but then you would be into designing your own.
The electrolitic caps will be to save cost and possibly space, large value foil caps are big.
If you are spending that sort of money, I recomend buying a measurement microphone, or making one with a capsule and downloading Holm impulse, it will allow you to measure your design and adjust the tweeter as well as confirm you have built it correctly. You only need a computer with a half decent sound card to make quite good measurements above the first reflection time.
It is also the best way to start to understand how frequency response affects sound.
Regards,
Andy
HOLM Acoustics
Website for Holm impulse above its free.
Wm 61a is the part number for a measurement microphone capsule. They are now obsolete but you can still get them and there are loads of guides on how to make a quite good microphone for about £5 with one of these. Search ebay for a supplier of small quantaties.
Or just by a mic from Holm or Beringer make an OK one as well.
Regards,
Andrew
Website for Holm impulse above its free.
Wm 61a is the part number for a measurement microphone capsule. They are now obsolete but you can still get them and there are loads of guides on how to make a quite good microphone for about £5 with one of these. Search ebay for a supplier of small quantaties.
Or just by a mic from Holm or Beringer make an OK one as well.
Regards,
Andrew
Thanks so much for the very helpful information.
I will definitely get a mic and start figuring out the software with my current speakers.
The woofer is made by Seas, the tweeter used to be a Foster/Tonegen unit. I don't know if it still is as they seem to be out of business for some time(?).
Thanks again,
Ej
I will definitely get a mic and start figuring out the software with my current speakers.
The woofer is made by Seas, the tweeter used to be a Foster/Tonegen unit. I don't know if it still is as they seem to be out of business for some time(?).
Thanks again,
Ej
Hi,
FWIW no way is the tweeter filter a conjugate arrangement.
Its elliptic, 1st order followed by a deep notch at tweeter Fs.
rgds, sreten.
FWIW no way is the tweeter filter a conjugate arrangement.
Its elliptic, 1st order followed by a deep notch at tweeter Fs.
rgds, sreten.
Thanks for comming back on this Sreten, I can see what you mean now. The notch is far to deep for a congugate.
Its not a configuration I have seen used before and at this low an order I didnt attach it to the term elliptic.
Thanks,
Andrew
Its not a configuration I have seen used before and at this low an order I didnt attach it to the term elliptic.
Thanks,
Andrew
As the woofer is big, the crossover point needs to be as low as possible.
Similar to this ( Nardi used to do AN assistance 🙄 )Diego Nardi - diffusore La Tantarchia Strifida
( the woofer is custom either, *tigther suspension* for PS 😕 )
Similar to this ( Nardi used to do AN assistance 🙄 )Diego Nardi - diffusore La Tantarchia Strifida
( the woofer is custom either, *tigther suspension* for PS 😕 )
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