I am just getting into speakers DIY, digging through Loudspeaker Design Cookbook currently
However I would like to approach this from the other end as well and get some advice from the experienced crowd
These are specs of 12" speakers I am thinking to start with
What would you recommend to build? This is for my office and probably mono only. Size limitation would be no 1.5m baffles please, otherwise open to ideas
Fs 38Hz
Re 6R4
Qts 0.42
Qes 0.46
Qms 4.29
Vas 179l
Mms 43g
Cms 0.41mm/N
Xmax 4.5mm
Thanks
However I would like to approach this from the other end as well and get some advice from the experienced crowd
These are specs of 12" speakers I am thinking to start with
What would you recommend to build? This is for my office and probably mono only. Size limitation would be no 1.5m baffles please, otherwise open to ideas
Fs 38Hz
Re 6R4
Qts 0.42
Qes 0.46
Qms 4.29
Vas 179l
Mms 43g
Cms 0.41mm/N
Xmax 4.5mm
Thanks
Back-calculating the missing data from what's supplied, and further assuming
a/ the data is accurate, and b/ you're running a normal voltage source amplifier rather than something with a higher output impedance (e.g. a SET amplifier), then something like a 121.5 litre vented box tuned to 38Hz would be a reasonable start. If you can stretch to a larger cabinet, it should suit Vb = Vas, Fb = Fs. In both cases, damp as desired using the old click test.
Vb = box volume when space taken up by driver, bracing & vent is accounted for
Fb = box tuning frequency
Click test = attached
We can go larger, but you imply some reasonable size limits, so these are about as small as you can get with a vented box with decent quality. If you prefer sealed, with the same assumptions about data & amplifier mentioned above, then 100 litres should give roughly a Butterworth alignment, with about 227 litres being approximately Bessel.
a/ the data is accurate, and b/ you're running a normal voltage source amplifier rather than something with a higher output impedance (e.g. a SET amplifier), then something like a 121.5 litre vented box tuned to 38Hz would be a reasonable start. If you can stretch to a larger cabinet, it should suit Vb = Vas, Fb = Fs. In both cases, damp as desired using the old click test.
Vb = box volume when space taken up by driver, bracing & vent is accounted for
Fb = box tuning frequency
Click test = attached
We can go larger, but you imply some reasonable size limits, so these are about as small as you can get with a vented box with decent quality. If you prefer sealed, with the same assumptions about data & amplifier mentioned above, then 100 litres should give roughly a Butterworth alignment, with about 227 litres being approximately Bessel.
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Thanks, noted
I understand damping from SET amp will be lower. What would that mean with practical design? Where to read about this part better?
I understand damping from SET amp will be lower. What would that mean with practical design? Where to read about this part better?
In effect, Qts is increased with a direct-coupled unit. In T/S alignment terms, assuming Vas and Fs are static, the box volume requirement increases. For a given size of sealed box, Qtc will increase; in vented boxes you will get more of a peaking alignment above Fb.
The two vented boxes I gave you above are pre-T/S alignments as it happens, since I don't know what the driver is, and have no real way of knowing how accurate the data above might be. They aren't necessarily as precise in ultimate terms but effective within broad limits, if you damp them properly.
The two vented boxes I gave you above are pre-T/S alignments as it happens, since I don't know what the driver is, and have no real way of knowing how accurate the data above might be. They aren't necessarily as precise in ultimate terms but effective within broad limits, if you damp them properly.
Right, thanks. Did some more reading and did math for closed box. Adjusting Qes for SET's Rout (circa 2R5 in my case) sends the box volume way higher. No universal recipe here, who would have known
I will leave vented box for the next project, as I see troubles coming from many ends here
The speaker is from Noema, a small Russian manufacturer a friend told me about
I will leave vented box for the next project, as I see troubles coming from many ends here
The speaker is from Noema, a small Russian manufacturer a friend told me about