Hi!
I am new to the diy scene and this will be my first project.
For the moment i have a lot of doubts about what path to choose.
Can somebody please help to decide what kind of speaker would better fit the Beyma 12xa30nd driver:
Big TQTW?
Big Bass reflex?
Small bass reflex?
Back wave horn?
It will be used as an hifi speaker, at home, in a moderate sized room (+/-36sqm) to be played at moderate levels.
I want high sensitivity in order to use low wattage amplifiers (8 a 40W)
I am looking forward for your feedback.
Thank you in advance for all the support I hope to get. 🙂
I am new to the diy scene and this will be my first project.
For the moment i have a lot of doubts about what path to choose.
Can somebody please help to decide what kind of speaker would better fit the Beyma 12xa30nd driver:
Big TQTW?
Big Bass reflex?
Small bass reflex?
Back wave horn?
It will be used as an hifi speaker, at home, in a moderate sized room (+/-36sqm) to be played at moderate levels.
I want high sensitivity in order to use low wattage amplifiers (8 a 40W)
I am looking forward for your feedback.
Thank you in advance for all the support I hope to get. 🙂
I think for the beginning a closed box will be good.
You can calculate the volume of the cabinet with Qt=0.21 and Qts=0.5 backwards.
You can calculate the volume of the cabinet with Qt=0.21 and Qts=0.5 backwards.
Thank you for the reply.
I won't be getting much bass out of it, will I ?
F-3 around 150hz ... I would like to have the F-3 at around 50hz
I won't be getting much bass out of it, will I ?
F-3 around 150hz ... I would like to have the F-3 at around 50hz
From memory it does very well in small bass reflex, but F3 50 Hz is probably not going to happen.
In don't think it works well in high Q applications. On OB it needs bass support, and I highly doubt it will work well in TQWT or horns.
Because it is intended as a monitor, it does not have much going on below 100hz. I found the best way to use it was a small closed box with a good LF driver to move some air. With an active LF amp we needed only about 10w on the Beyma to fill large living rooms.
You can use room reinforcement techniques to get an lower corner frequency. I find a speaker with modest LF extensions can sound quite enjoyable when listened to in nearfield and speaker a little closer to back wall.
Finally, you can use electrical techniques to increase the q of the woofer and deploy it in suitable applications, at the loss of efficiency.
In don't think it works well in high Q applications. On OB it needs bass support, and I highly doubt it will work well in TQWT or horns.
Because it is intended as a monitor, it does not have much going on below 100hz. I found the best way to use it was a small closed box with a good LF driver to move some air. With an active LF amp we needed only about 10w on the Beyma to fill large living rooms.
You can use room reinforcement techniques to get an lower corner frequency. I find a speaker with modest LF extensions can sound quite enjoyable when listened to in nearfield and speaker a little closer to back wall.
Finally, you can use electrical techniques to increase the q of the woofer and deploy it in suitable applications, at the loss of efficiency.
The fact that you want to drive it with a tube amp, which usually have low damping factor, will help a little regarding LF reproduction.
The best would be to find out the amp's series output resistance and from there you can calculate the resulting Qes and Qts. With this new paramters a slightly more bass-friendly tuning should be achievable.
Regards
Charles
The best would be to find out the amp's series output resistance and from there you can calculate the resulting Qes and Qts. With this new paramters a slightly more bass-friendly tuning should be achievable.
Regards
Charles
Thank you for the feedback!
I would like to use a passive xover.
Beyma has a 2way xover that I was thinking of using, the FD2XA.
As suggested I could add to the design a woofer, maybe an 18' to keep the sensitivity high. The box would start to look like a classic JBL, say a 4345, which I like 🙂
The problem would be then to design the xover ...
I would like to use a passive xover.
Beyma has a 2way xover that I was thinking of using, the FD2XA.
As suggested I could add to the design a woofer, maybe an 18' to keep the sensitivity high. The box would start to look like a classic JBL, say a 4345, which I like 🙂
The problem would be then to design the xover ...
If you can get roughly 2-3ohm of drive impedance from the amplifier + DCR of any series coil for the woofer crossover leg, 50L-60L tuned anywhere from 45Hz to 55Hz depending on your taste looks fair enough. It still won't do low bass and f3 will be the the mid-50ies at best.
With Qts=0.21, the Beyma 12xa30nd would favor a large rear horn to extend the bass to 40 Hz.
Modular Speakers: One diyAudio strategy which gives your life musical options.
1) Low A on a Piano is 27.5Hz .... build high efficiency woofers that are equalized to be flat at 27.5Hz in your room.
The design should be constructed to easily accept different T-M tops.
.... maybe.. Side-side pair of counter-force 18" woofers like Beyma 18LX60v1, Peavey LoRider18 479910
2)The Beyma 12xa30nd will sound best in a sealed box, your first top. There are both standard_Beyma and custom_DIY crossovers available to study. Only a Xover designed for your box will produce the best result.
QTC of 0.7, 16ltr box, f3 117Hz.
QTC of 0.5, 36ltr box, f3 129Hz.
....future options
3) maybe sealed box Faital 12FH530 OR Lambda TD12M midbass, plus Beyma TPL-150H AMT tweeter OR
SEOS15 waveguide OR XR64 horn OR LeCleach horn.
We all want to have a life with GOOD options.
Modular Speakers: One diyAudio strategy which gives your life musical options.
1) Low A on a Piano is 27.5Hz .... build high efficiency woofers that are equalized to be flat at 27.5Hz in your room.
The design should be constructed to easily accept different T-M tops.
.... maybe.. Side-side pair of counter-force 18" woofers like Beyma 18LX60v1, Peavey LoRider18 479910
2)The Beyma 12xa30nd will sound best in a sealed box, your first top. There are both standard_Beyma and custom_DIY crossovers available to study. Only a Xover designed for your box will produce the best result.
QTC of 0.7, 16ltr box, f3 117Hz.
QTC of 0.5, 36ltr box, f3 129Hz.
....future options
3) maybe sealed box Faital 12FH530 OR Lambda TD12M midbass, plus Beyma TPL-150H AMT tweeter OR
SEOS15 waveguide OR XR64 horn OR LeCleach horn.
We all want to have a life with GOOD options.
Attachments
Hi.
Thank you LineSource for your post.
Yes, the 12xa30nd on top with a big driver on the bottom would be a cool solution, but I think I will leave it for later. The xover would be a little bit too challenging.
Regarding the 12xa30nd solo, using the online calculators I seem to get a response down to 40hz with a 120L bass reflex box.
And even further down with a 200L box...
Am I missing something?
Rgs
Thank you LineSource for your post.
Yes, the 12xa30nd on top with a big driver on the bottom would be a cool solution, but I think I will leave it for later. The xover would be a little bit too challenging.
Regarding the 12xa30nd solo, using the online calculators I seem to get a response down to 40hz with a 120L bass reflex box.
And even further down with a 200L box...
Am I missing something?
Rgs
Vent loading upon the driver will be over a very narrow bandwidth, so will output (and peaky) and group delay will be quite high. This sort of alignment might be OK for some deeper bass in a boombox, but not for hi-fi IMO. The driver's Qe/Qt is so low that it needs to be impedance-matched either (or both) to the air by a sizable horn, or electrically by drive impedance from the amplifier. 60L tuned to 45Hz looks good if ~2ohm of drive impedance is available. 75L tuned to 40Hz if ~4ohm. DCR of coils in the passive crossover can be part of this and should be taken into account in any case.
Doppler type high+low_freq Intermodulation Distortion can become audible on a wide bandwidth speaker. Simple conservative simulations of Beyma 12XA30Nd IMD at 94db SPL illustrate that most listeners will hear IMD(Doppler Distortion) in a 2-way pushing the 12XA30Nd down near 40Hz, but not in a 3-way with the 12XA30Nd Xover ~100Hz.
Plots of ported cabinets pushing low Qtc drivers to low frequencies show large transfer function phase shifts. The Beyma 12xa30nd will sound best in a sealed box.
Low A on a Piano is 27.5Hz ....
Plots of ported cabinets pushing low Qtc drivers to low frequencies show large transfer function phase shifts. The Beyma 12xa30nd will sound best in a sealed box.
Low A on a Piano is 27.5Hz ....
Attachments
LS thanks.
I have a lot of questions, if you dont mind.
Would you go for the 16L or the 36L sealed cabinet?
The Beyma 18' is difficult to find the v1 only the v2.
Is it the same to use one or the other?
Do i need to go with two opposing drivers?
Can a bass box only with 1 driver be an option?
I would like the speaker to be easy to drive by smaller amps, including tube amps, from 8W to 50W do you think this would be workable with this design?
I will need a xover that incorporates the 3 drivers, do you have a suggestion?
How do I equalize the bass in the room? Is it through the crossover?
Thank you all for the support.
I have a lot of questions, if you dont mind.
Would you go for the 16L or the 36L sealed cabinet?
The Beyma 18' is difficult to find the v1 only the v2.
Is it the same to use one or the other?
Do i need to go with two opposing drivers?
Can a bass box only with 1 driver be an option?
I would like the speaker to be easy to drive by smaller amps, including tube amps, from 8W to 50W do you think this would be workable with this design?
I will need a xover that incorporates the 3 drivers, do you have a suggestion?
How do I equalize the bass in the room? Is it through the crossover?
Thank you all for the support.
I would make it modular. That would allow you to start off with the coax alone and then add low-end extension later on. I would go for an active crossover between coax and low end and an SS amp for the latter.
With a 36 liter box you would even be able to get some low end. LF equalisation would best be done before the power amp.
You will not be able to listen very loud with the coax alone in the closed box in the beginning. I once did a very small closed box with a 8" Beyma coax. It was EQes down to the 50ies. Very nice to listen to in the nearfield but it definitela had limits when it came to bass-heavy stuff.
I am now waiting for the opportunity to make a low-end extension for that one.
Regards
Charles
With a 36 liter box you would even be able to get some low end. LF equalisation would best be done before the power amp.
You will not be able to listen very loud with the coax alone in the closed box in the beginning. I once did a very small closed box with a 8" Beyma coax. It was EQes down to the 50ies. Very nice to listen to in the nearfield but it definitela had limits when it came to bass-heavy stuff.
I am now waiting for the opportunity to make a low-end extension for that one.
Regards
Charles
it might be helpful to contact one of the posters in this thread DIY Audio Projects Forum • Beyma, a Spanish coaxial driver
I already bought the 12xa30nd, so the design will have to be around this drive or solo or with a bass driver to complement it.