Hello all happy DIY people
I might have painted myself into a corner, but I thought, maybe a grown man can still learn something 🤓
It all started with a friend calling me, asking if I had some driver lying around.
I said - yes - what's this about?
He explained, that he knew a guy, that wanted to have some better speakers - also bigger, with some bass and good top.
Pretty generic I thought - but I quickly mentioned that I had 4 x SB23NRX - 8ohm, some Dayton RS125 - 8ohm and Seas DXT's - which might become something - and instead of collecting dust, they might make someone happy, and I get to clean out some shelves.
But.... I only tried to build active systems, so I'm all "green" here 😳
The friend of a friend, is happy with most looks and sizes, so I have quite some freedom. But how do I get started on making a passive cross-over for these drivers?
As an active speaker guy, I'm thinking 85-90 liter closed for the woofers, 2 for the midrange - and around 400 and 2200 for cross-over points.
The guy has a NAD 80W integrated.
I might have painted myself into a corner, but I thought, maybe a grown man can still learn something 🤓
It all started with a friend calling me, asking if I had some driver lying around.
I said - yes - what's this about?
He explained, that he knew a guy, that wanted to have some better speakers - also bigger, with some bass and good top.
Pretty generic I thought - but I quickly mentioned that I had 4 x SB23NRX - 8ohm, some Dayton RS125 - 8ohm and Seas DXT's - which might become something - and instead of collecting dust, they might make someone happy, and I get to clean out some shelves.
But.... I only tried to build active systems, so I'm all "green" here 😳
The friend of a friend, is happy with most looks and sizes, so I have quite some freedom. But how do I get started on making a passive cross-over for these drivers?
As an active speaker guy, I'm thinking 85-90 liter closed for the woofers, 2 for the midrange - and around 400 and 2200 for cross-over points.
The guy has a NAD 80W integrated.
Interesting idea 👍
I already have a small cabinet for the RS125 with the DXT, crossed around 2100 with LR24, which works well. So crossing those around 4-500Hz and putting them atop of a pair of SB's shouldn't be that hard... maybe 🤔
I'm still chasing the closed design for the woofers, since that should give a smoother roll off and easier to design.
If I could chat him into a semi-active design, with a pre-out on the NAD to a DSP-amp to power the woofers, it would also make in-room adjustment a ton easier, leaving me only one cross-over to deal with between mid and tweeter ... hmm. Gotta see what I can make him live with 😆
I already have a small cabinet for the RS125 with the DXT, crossed around 2100 with LR24, which works well. So crossing those around 4-500Hz and putting them atop of a pair of SB's shouldn't be that hard... maybe 🤔
I'm still chasing the closed design for the woofers, since that should give a smoother roll off and easier to design.
If I could chat him into a semi-active design, with a pre-out on the NAD to a DSP-amp to power the woofers, it would also make in-room adjustment a ton easier, leaving me only one cross-over to deal with between mid and tweeter ... hmm. Gotta see what I can make him live with 😆
Is 90 liter CB really what you need for two SB woofers? Next to that, I expect the Dayton might get into ((thermical ) trouble at higher levels if run from 400Hz upwards.
Any idea about baffle size and cabinet shape? Tower with 28-30cm baffle width? Chamfers at mid and tweeter height?
Maybe a discussion about the cost of a decent lowpass for the woofer and highpass for the mid could lead to a discussion about semi-active design. These get close to a MiniDSP plus stereo amp quickly.
Any idea about baffle size and cabinet shape? Tower with 28-30cm baffle width? Chamfers at mid and tweeter height?
Maybe a discussion about the cost of a decent lowpass for the woofer and highpass for the mid could lead to a discussion about semi-active design. These get close to a MiniDSP plus stereo amp quickly.
It is a learning curve.
But the factory frequency response data can be traced and simulated on the baffle size you design.
Then with impedance data which can be traced as well.
A crossover can designed in simulation.
Off axis data is generated as well with baffle simulation.
So far better than wild guessing.
2x8" woofers and the mids and tweets mentioned should be a rather nice system.
Lower woofer can be crossed lower.
Steep learning curve but can all be done with the various tools in Virtuix Cad
Passive is always the simple way to go, 2 wires to the speaker and any amp can run it.
But the factory frequency response data can be traced and simulated on the baffle size you design.
Then with impedance data which can be traced as well.
A crossover can designed in simulation.
Off axis data is generated as well with baffle simulation.
So far better than wild guessing.
2x8" woofers and the mids and tweets mentioned should be a rather nice system.
Lower woofer can be crossed lower.
Steep learning curve but can all be done with the various tools in Virtuix Cad
Passive is always the simple way to go, 2 wires to the speaker and any amp can run it.
Speaker will be 4 ohm, and will possibly dip below 3 ohm.
Check your sensitivities. You won't have easy adjustment like an active speaker.
Verify placement in the room in order to better design the amount of BSC.
Find out if the future owner is an audiophile, or just looking to make some noise?
Just thinking out loud, but what if two woofers are used as a sub? Then make a 3-way with tmw only.
Woofers are 8 ohm and with .5 crossover impedance would be closer to = 6 ohm
88 dB and 86 dB rather perfect match, tweeter is padded.
88 dB and 86 dB rather perfect match, tweeter is padded.
Thanks guys 👍
Sadly, he just told me that the workshop he was promised to work in, got closed 😢
Could have been awesome, since he used to build guitars and stuff, hopefully ending up with a very good finish.
I'll definitely let you know if he picks it up again somehow 🙂
Sadly, he just told me that the workshop he was promised to work in, got closed 😢
Could have been awesome, since he used to build guitars and stuff, hopefully ending up with a very good finish.
I'll definitely let you know if he picks it up again somehow 🙂