I would like to avoid excessive complexity.
Maybe the better is to add to each speaker its own active subwoofer that can be fed from the loudspeaker terminals, like the subwoofers from REL do. I think I might be better off buying the subwoofers than making them myself ... being active and so on
I was involved in the initial design of a product that was to use a 12XA and 15P or 15SW for bass support. The upper box carried the 12XA and was around 20L closed, the lower box was ~120L ported. It was a single speaker, the upper box carried the amps at its back so it wouldn't look like Quasimodo. The objective was to fill very large rooms with proper high fidelity sound, which is not possible with 'normal' hifi speakers.
The big difference was that it was to be a fully active system, though a passive option for the was to be later developed for the upper driver so folks could use it with their own tube amps. We never got to it (I got a better offer!!), but the simulations of the active system were excellent.
The smaller drivers were actually much better for solo use than the bigger ones. The ferrite 8CX for example, could deliver good bass in a regular size floorstander and the CD could be crossed at ~1.5k. That was probably the best of the candidates, even though IIRC the distortion was slightly higher than the neo models.
I don't think you should worry too much about it. as has been mentioned before, you should go for a target Qtc of ~0.6-0.7 and the tube amp will help fill in the bottom end. I think subjectively we prefer total system Q of ~0.8-0.9, so the design needs to differ slightly (my view) for SS and tube.
The big difference was that it was to be a fully active system, though a passive option for the was to be later developed for the upper driver so folks could use it with their own tube amps. We never got to it (I got a better offer!!), but the simulations of the active system were excellent.
The smaller drivers were actually much better for solo use than the bigger ones. The ferrite 8CX for example, could deliver good bass in a regular size floorstander and the CD could be crossed at ~1.5k. That was probably the best of the candidates, even though IIRC the distortion was slightly higher than the neo models.
I don't think you should worry too much about it. as has been mentioned before, you should go for a target Qtc of ~0.6-0.7 and the tube amp will help fill in the bottom end. I think subjectively we prefer total system Q of ~0.8-0.9, so the design needs to differ slightly (my view) for SS and tube.
Here are some interesting speakers I like or a representation of.
As Linesource suggested, the modular approach is much better in the long run, enabling me to change and experiment with the T/M module.
And that's the way I want to go, so although some of the speakers are in 'one piece' the objective is to separate the bass from the T/M.
As Linesource suggested, the modular approach is much better in the long run, enabling me to change and experiment with the T/M module.
And that's the way I want to go, so although some of the speakers are in 'one piece' the objective is to separate the bass from the T/M.
Attachments
Hi Sangram!
The system is for home use, it will not be extremely stressed playing at high volumes, actually I prefer to play at lower levels.
Some speakers only play well at high levels, some seem to convey all the musical expression immediately from low levels and that's much better for home use and it is what I am looking for ...
If I understand correctly, for tubes you suggest a lower Q, say 0,6 and for SS an higher Q of 0.8/0.9, correct?
I would like to keep the efficiency and impedance of the all system as high as possible, would I manage that with the 15' drivers you mentioned for the bass?Would i get a better result from an 18'?
I would prefer to keep everything passive, the system is less cluttered that way.
The system is for home use, it will not be extremely stressed playing at high volumes, actually I prefer to play at lower levels.
Some speakers only play well at high levels, some seem to convey all the musical expression immediately from low levels and that's much better for home use and it is what I am looking for ...
If I understand correctly, for tubes you suggest a lower Q, say 0,6 and for SS an higher Q of 0.8/0.9, correct?
I would like to keep the efficiency and impedance of the all system as high as possible, would I manage that with the 15' drivers you mentioned for the bass?Would i get a better result from an 18'?
I would prefer to keep everything passive, the system is less cluttered that way.
Here you can see another nice example with your driver:
aktives-hoeren.de • Thema anzeigen - Jubiläums-Edition "Quintus" von Sonus Natura
Regards
Charles
aktives-hoeren.de • Thema anzeigen - Jubiläums-Edition "Quintus" von Sonus Natura
Regards
Charles
Not really given it can't make it to a suitable crossover point without breaking up.
Hi
The best tradeoff we found on that project was with a 15" bass unit - we had settled on the Selenium 15SW800 for cost reasons I think. The box size was manageable, extension was superb and with a good amp (think kilowatt or so) you could get some serious grunt out of the system. Getting the bass section to be passive may not be realistic, may be a bit challenging for a low power tube amp. The midrange should be fine if driven passively with a few watts.
But like I said, I think you should first try the Beyma on its own with a slightly overdamped box, and see how it works out for you. If you are going modular, a solution I like, you can do it in phases. You'd be surprised at what our ears are able to forgive 😀
I have never, ever managed to figure out how Q is measured once the speakers are in the box and connected to an amplifier, so I tend to slightly overdamp when the speaker in question is to be played with tube amps. Else the bass becomes too flabby at realistic levels. This is totally personal taste though, a lot of people prefer it the other way around.
Assuming a sealed or true aperiodic enclosure, the system Q (Qtc) is measured the same way you measure driver free-air parameters. Qts becomes Qtc, Fs becomes Fc, that's it!
Hi
Can you please give me some suggestions for the box using the 12xa30nd on its own.
Maybe as a BR box (Beyma suggests BR for their PA speakers with this driver...), I can always plug close the ports afterwards.
What do you think?
Can you please give me some suggestions for the box using the 12xa30nd on its own.
Maybe as a BR box (Beyma suggests BR for their PA speakers with this driver...), I can always plug close the ports afterwards.
What do you think?
Are you speaking from experience? I'm not experienced but I think it should be possible to crossover at 900-1000 Hz for home use.
I once contacted Beyma regarding the lowest recommended X-over frequency for the 12XA30nd when used in a low power situation (i.e. max peak power around 10 Wattts on the tweeter).
The answer was that they would recommend around 1 kHz for a 2nd order highpass.
On their website they recommend 1.2 kHz with a 2nd order crossover, which isn't very high either.
Regards
Charles
The answer was that they would recommend around 1 kHz for a 2nd order highpass.
On their website they recommend 1.2 kHz with a 2nd order crossover, which isn't very high either.
Regards
Charles
gafhenderson and I were talking about Beyma 15XA38ND but the tweeter in that will of course go just as low as the one in 12XA30ND. 800-900 Hz or lower should be feasible with 4'th order
Hello altogether!
i`m new at this Forum
@ Audiomig:
In the beginning of this Thread you wrote about a medium sized enclosure for the 12"XA30ND, you have already Buyed the Speakers.
My reconomation is a Bassrefelex-Enclosure with a internal Volume of 31 Litres.
Port Diameter is 70mm, Port Lenght is 91mm. AND an active Highpass-Filter with a Cutoff-Frequency of 52,5 Hz by a Filter-Q of 1,93.
so the predictet -3dB Frequency of the System will be at ca. 50Hz.
Ok, this is not really a deep Bass but it is well for a 12inch Speaker with high eficiency.
If you like i can workout and post the active Filter for you and Show the result of my Software - howevwe i Need some Time to do this.
Please excuse that my English is not the best.
Regards Jörg
i`m new at this Forum
@ Audiomig:
In the beginning of this Thread you wrote about a medium sized enclosure for the 12"XA30ND, you have already Buyed the Speakers.
My reconomation is a Bassrefelex-Enclosure with a internal Volume of 31 Litres.
Port Diameter is 70mm, Port Lenght is 91mm. AND an active Highpass-Filter with a Cutoff-Frequency of 52,5 Hz by a Filter-Q of 1,93.
so the predictet -3dB Frequency of the System will be at ca. 50Hz.
Ok, this is not really a deep Bass but it is well for a 12inch Speaker with high eficiency.
If you like i can workout and post the active Filter for you and Show the result of my Software - howevwe i Need some Time to do this.
Please excuse that my English is not the best.
Regards Jörg
Thank you Jorg!
Thats what I needed 🙂
I had figured out that the enclosure woud be around 30L but had doubts about the port and the xover.
When you speak about active filter what you mean? is it like a minidsp?
Thank uou again.
Thats what I needed 🙂
I had figured out that the enclosure woud be around 30L but had doubts about the port and the xover.
When you speak about active filter what you mean? is it like a minidsp?
Thank uou again.
Hi !
I dont know much about the MINIDSP but i think that a MINIDSP or another DSP can simulate this Filter. But if you buy a DSP for just one Filter it would be to expensive.
The Flow of the Audio-Signal is similar to the Minidsp - the Active Filter is just the analog Version and can not be programmed. It will be Equated and build with an OP (operational Amplifier ) for Example a TL 072 (Cost 40cent ) a few Resistors and Capacitors , a Veroboard or a PCB.. and a +-15V Powersupply.
If you have already a DSP it should be possible to Simulate.
regards Jörg
I dont know much about the MINIDSP but i think that a MINIDSP or another DSP can simulate this Filter. But if you buy a DSP for just one Filter it would be to expensive.
The Flow of the Audio-Signal is similar to the Minidsp - the Active Filter is just the analog Version and can not be programmed. It will be Equated and build with an OP (operational Amplifier ) for Example a TL 072 (Cost 40cent ) a few Resistors and Capacitors , a Veroboard or a PCB.. and a +-15V Powersupply.
If you have already a DSP it should be possible to Simulate.
regards Jörg
Hi Jorg
Thank you, that would be great.
I don't have a DSP, meanwhile I went to see what what an active filter was. Saw your graphic as well, it greatly adds to the extension of the speaker.
If you can provide me with the schematic for the xover/active filter I would really appreciate it.
Thank you again.
Rgs
Thank you, that would be great.
I don't have a DSP, meanwhile I went to see what what an active filter was. Saw your graphic as well, it greatly adds to the extension of the speaker.
If you can provide me with the schematic for the xover/active filter I would really appreciate it.
Thank you again.
Rgs