I did initially try the variable l-pad idea and it seemed to work ok, but I don't like variable l-pads as I prefer having less things to tweak.
As a variable L-pad is adjusted toward greater attenuation, the crossover begins to see the nominal impedance regardless of the speaker impedance.. and as it's adjusted toward no attenuation, the speaker impedance dominates.
That could explain why I saw no real difference using the zobel on the midax. The attenuation I used with fixed resistors would have caused little effect from the rising impedance of the midax.
For the amp I wanted a matched set of knobs as I have an input level control and a volume control.
So what I did is this. I have a Heathkit A9C amp I bought to restore which has one broken knob. So I ordered three decent looking knobs for it so they all match and decided to use the two good original knobs for the amp used with this speaker.
For the amp I wanted a matched set of knobs as I have an input level control and a volume control.
So what I did is this. I have a Heathkit A9C amp I bought to restore which has one broken knob. So I ordered three decent looking knobs for it so they all match and decided to use the two good original knobs for the amp used with this speaker.
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What effect to the sound would be caused if I put actual sides and a top on the speaker baffle?
As I said before about your open back cardboard enclosure, the effect would be one of a boomy, one note bass.
I suggest a solid back panel drilled with a series of small holes - a form of aperiodic loading that gives a transient fast and resonance free bass response.
My old 3 cu ft enclosures had a solid back panel in which there were ten rows of fifteen, 0.5" diameter holes, covered internally by soft woolen cloth for extra acoustic resistance. You could scale the number of holes to suit your cubic volume.
I suggest a solid back panel drilled with a series of small holes - a form of aperiodic loading that gives a transient fast and resonance free bass response.
My old 3 cu ft enclosures had a solid back panel in which there were ten rows of fifteen, 0.5" diameter holes, covered internally by soft woolen cloth for extra acoustic resistance. You could scale the number of holes to suit your cubic volume.
I suppose it's just gonna take some time to get used to the better sound of the open baffle.
I think one issue is the two woofers.
The bass seems to not sound quite as good closer to the speaker, but when I get back from it about 4' it sounds a bit better.
When I originally bought the Goodmans drivers and crossovers I had fully intended to buy a Goodman's woofer that would have been used with those drivers, but I wound up being outbid at the last second.
That said are there any 12" 8 ohm woofers that have better bass response open baffle than the RCA woofers?
I think one issue is the two woofers.
The bass seems to not sound quite as good closer to the speaker, but when I get back from it about 4' it sounds a bit better.
When I originally bought the Goodmans drivers and crossovers I had fully intended to buy a Goodman's woofer that would have been used with those drivers, but I wound up being outbid at the last second.
That said are there any 12" 8 ohm woofers that have better bass response open baffle than the RCA woofers?
You might find this an interesting read: https://www.monacor.com/magazine/op...first time are first irritated, then thrilled.
Quote 1: "Open baffle can do bass too, but just differently."
Quote 2: "To benefit from the extraordinary effect of an open baffle, you must not place speakers without rear panel directly in front of a wall. The open baffle needs a distance of about 1 metre from the wall. The bass reproduction is most effective if you place the speaker at approximately ⅓ of the room length."
Quote 1: "Open baffle can do bass too, but just differently."
Quote 2: "To benefit from the extraordinary effect of an open baffle, you must not place speakers without rear panel directly in front of a wall. The open baffle needs a distance of about 1 metre from the wall. The bass reproduction is most effective if you place the speaker at approximately ⅓ of the room length."
That's probably a rhetorical question!
However, as I mentioned earlier, the woofer would theoretically require a high Qts (> 0.77), and a relatively high resonance frequency Fs (40-60 Hz).
For such a woofer we can turn to the Pro loudspeaker market and look at drivers such as the Eminence Alpha-12A.
https://eminence.com/products/alpha_12a#specifications
Thing is if I do use different drivers I'll likely have to re-do the l-pads for the midax and tweeter.
Also I wonder if the RCA woofers being made when gobs of power wasn't readily available makes them better for certain things like open baffle.
Also do the small side pieces I used affect the sound any?
Also I wonder if the RCA woofers being made when gobs of power wasn't readily available makes them better for certain things like open baffle.
Also do the small side pieces I used affect the sound any?
Any departure from a flat baffle is undesirable reproduction wise, so the side piece depth should be kept to a minimum.
Look at how the side pieces in post #108 reduce in depth the further up they go.
The best support would be skeletal in construction.
Look at how the side pieces in post #108 reduce in depth the further up they go.
The best support would be skeletal in construction.
When it sounds right to you, it should sound right straight away... However with many issues going on at once it will be difficult to draw conclusions or make generalisations.
For me I find that I get used to how something sounds and when I discover something isn't right and fix it I have to get used to the new sound.
It's like when I upgraded my stereo at work with Klipsch bookshelf speakers. Didn't sound right at first as I weas used to the brighter sound of my DIY speakers and the vintage amp I used with them. Once I got used to the Klipsch they sounded much better than what I had.
The side supports are like this. Granted I should have used the same thickness of wood as I used for the baffle, but the wood was already expensive enough so I opted for a thinner 2' X 2' piece for the sides and bottom.
Also the speaker grills came in today. Will install them tomorrow.
When I get them installed I might see if I am allowed to take a couple pictures and post them here.
https://www.monacor.com/magazine/open-baffle-katana-m1
I think I'm currently still in the irritated phase. Of course it doesn't help that nearby test stations have noisy fans and there's no telling what the copper screen material is doing to the sound.
I suppose that's why I no longer need the speaker aimed exactly where I normally am in the screen room in order to hear it properly and I can move around in the room and still hear it good so long as I am within the vertical and horizontal dispersion pattern of the midax and tweeter.
Given the way the partial thin wood panel is on the front of the screen room being maybe 2- 2 1/2 feet high and it being the only partial wall, that is likely affecting the bass reproduction. Now if I had the necessary space I could try moving the speaker out from the partial wall about 3' and see if there's any bass improvement. That could also explain why the bass seems to sound ok on some songs but not others.
It's like when I upgraded my stereo at work with Klipsch bookshelf speakers. Didn't sound right at first as I weas used to the brighter sound of my DIY speakers and the vintage amp I used with them. Once I got used to the Klipsch they sounded much better than what I had.
The side supports are like this. Granted I should have used the same thickness of wood as I used for the baffle, but the wood was already expensive enough so I opted for a thinner 2' X 2' piece for the sides and bottom.
Also the speaker grills came in today. Will install them tomorrow.
When I get them installed I might see if I am allowed to take a couple pictures and post them here.
https://www.monacor.com/magazine/open-baffle-katana-m1
I think I'm currently still in the irritated phase. Of course it doesn't help that nearby test stations have noisy fans and there's no telling what the copper screen material is doing to the sound.
I suppose that's why I no longer need the speaker aimed exactly where I normally am in the screen room in order to hear it properly and I can move around in the room and still hear it good so long as I am within the vertical and horizontal dispersion pattern of the midax and tweeter.
Given the way the partial thin wood panel is on the front of the screen room being maybe 2- 2 1/2 feet high and it being the only partial wall, that is likely affecting the bass reproduction. Now if I had the necessary space I could try moving the speaker out from the partial wall about 3' and see if there's any bass improvement. That could also explain why the bass seems to sound ok on some songs but not others.
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That's a magnificent construction, amplifier and all! 😎
I'm sure you will soon get the desired buzz, glow and tingle from the open baffle.
Provided, of course, they are not suppressed by the Faraday cage! 😀
I'm sure you will soon get the desired buzz, glow and tingle from the open baffle.
Provided, of course, they are not suppressed by the Faraday cage! 😀
It will take time for me to get used to the sound. That said I may not get the full bass response due to where the speaker has to sit though.
I do need to do a couple things though.
1. Clean up the wiring.
2. Use longer metal pieces to secure the top and bottom pieces of the baffle.
I do need to do a couple things though.
1. Clean up the wiring.
2. Use longer metal pieces to secure the top and bottom pieces of the baffle.
I got the wiring cleaned up nicely.
Will get the metal pieces tomorrow.
I also need to find something to cover the 1/4" speaker plug as given I wired the amp up bridged the shell of the plug cannot contact the chassis.
Will get the metal pieces tomorrow.
I also need to find something to cover the 1/4" speaker plug as given I wired the amp up bridged the shell of the plug cannot contact the chassis.
Either the TDA2050 is wimpy in the bass or the Kenwood just works best with that speaker as the bass sounds better.
So I adjusted the idle current to 30mA and the voltage on the speaker terminals to 0Vdc and I honestly believe the Kenwood sounds a little better.
So I adjusted the idle current to 30mA and the voltage on the speaker terminals to 0Vdc and I honestly believe the Kenwood sounds a little better.