So, I took the woofers and SB65 to play with the Harsch XO at 350Hz. It's a bit low end limit for the SB65, but it sounds good so far. I might try a little higher, say 400Hz crossing next time.
Here's what it looks like... it was a bit noisy when I took the measurements... really hard to have it dead quiet in here.
Here's what it looks like... it was a bit noisy when I took the measurements... really hard to have it dead quiet in here.
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As said... OB style.
Eh! Not that bad... pretty nice in fact.
Even on the minimalist baffle, the dual 5x8 woofers have presence. And adding a +8db at 60Hz they can be very realistic (green line). Impulse still looks ok with the same Harsch XO at 350Hz.
I wonder if the MTM pattern still holds in an OB configuration....
Eh! Not that bad... pretty nice in fact.
Even on the minimalist baffle, the dual 5x8 woofers have presence. And adding a +8db at 60Hz they can be very realistic (green line). Impulse still looks ok with the same Harsch XO at 350Hz.
I wonder if the MTM pattern still holds in an OB configuration....
Attachments
Alright... preliminary tests... and I am puzzled.
Used a simple 2nd order XO on both, at 400Hz.
First, it looks like placing the SB65 way back there with the waveguide had zero effect, as we can still see the tweeter and the woofers arriving about 1.4ms later.
Also that very weird curve before 0 when the delay is applied... never seen that before. Wondering what it is. I'll switch back to Harsch XO in the next test to see if it's still there.
Another puzzling test.
I tried inverting the woofers, and it had almost no effect on the FR. Both FR curves match pretty well, no dip at the XO point, but as we can see in the impulse, the woofers are indeed inverted. Weird!
Also the ballistic curve before 0 is not present when the woofers are inverted.... ??
Would the waveguide prevent any phase issues between the woofers and tweeter? In combination with OB?
I'm not sure what to think of these measurements.... Doesn't help that I caught a big cold and my brain feels like jelly right now...
Used a simple 2nd order XO on both, at 400Hz.
First, it looks like placing the SB65 way back there with the waveguide had zero effect, as we can still see the tweeter and the woofers arriving about 1.4ms later.
Also that very weird curve before 0 when the delay is applied... never seen that before. Wondering what it is. I'll switch back to Harsch XO in the next test to see if it's still there.
Another puzzling test.
I tried inverting the woofers, and it had almost no effect on the FR. Both FR curves match pretty well, no dip at the XO point, but as we can see in the impulse, the woofers are indeed inverted. Weird!
Also the ballistic curve before 0 is not present when the woofers are inverted.... ??
Would the waveguide prevent any phase issues between the woofers and tweeter? In combination with OB?
I'm not sure what to think of these measurements.... Doesn't help that I caught a big cold and my brain feels like jelly right now...
Attachments
Sorry, I'm very slow over here.
Been hit with a monster ... Students around here LOVE getting sick, as it's their only way to get school off, stay at home, and play on their cellphone. The worst, the better! They are ecstatic when they get Influenza A as they are ordered by the school to stay at home for 9 days... So, kids are homing in the worst ones and try to get sick as well. And on the other end of the spectrum... I HATE being sick. Not a great situation for a teacher!
Anyway...
I'll continue doing some tests in full OB, then later on try to seal the woofers, just to get a little more oomph in the low end. They slam pretty good with a bit of EQ, but drop fast at 50Hz... so, most songs are ok, but very low end notes, like in Doing It Right - Daft Punk, it doesn't register (hits as low as 30Hz).
Listening impressions....
These do not have the pin point accuracy of some other builds I have. It's imaging well enough, but I'd say a little blurry. Impressions are that I have lost the feeling of having the instruments in the room around me and watching a movie about the performance. Didn't have that when the SB65 was on the baffle, only in the WG.
The amazing....
The sweet spot is HUGE! With the pin point imaging of the others, the sweet spot was like 30cm... move you head to the sides 30cm, or fore and aft, and the tone will change.
This one, I can sit anywhere on the couch, 4-people wide, and everyone has the same sound. I can stand up, and there's no change in the sound. I can sit right in front of the left speaker, and still get a stereo image from the right speaker. With absolutely no EQ or DSP processing other than the low end boost. Pretty cool!
I can hear the vibrating cardboard waveguide, so, that's not amazing. I'll try to dampen it a bit, but there's so much I can do with cardboard. Solid wood would be amazing, but a pain to do. 3D printing might be the way to go... There are resources online to find printers near your home... I'll check that.
Been hit with a monster ... Students around here LOVE getting sick, as it's their only way to get school off, stay at home, and play on their cellphone. The worst, the better! They are ecstatic when they get Influenza A as they are ordered by the school to stay at home for 9 days... So, kids are homing in the worst ones and try to get sick as well. And on the other end of the spectrum... I HATE being sick. Not a great situation for a teacher!
Anyway...
I'll continue doing some tests in full OB, then later on try to seal the woofers, just to get a little more oomph in the low end. They slam pretty good with a bit of EQ, but drop fast at 50Hz... so, most songs are ok, but very low end notes, like in Doing It Right - Daft Punk, it doesn't register (hits as low as 30Hz).
Listening impressions....
These do not have the pin point accuracy of some other builds I have. It's imaging well enough, but I'd say a little blurry. Impressions are that I have lost the feeling of having the instruments in the room around me and watching a movie about the performance. Didn't have that when the SB65 was on the baffle, only in the WG.
The amazing....
The sweet spot is HUGE! With the pin point imaging of the others, the sweet spot was like 30cm... move you head to the sides 30cm, or fore and aft, and the tone will change.
This one, I can sit anywhere on the couch, 4-people wide, and everyone has the same sound. I can stand up, and there's no change in the sound. I can sit right in front of the left speaker, and still get a stereo image from the right speaker. With absolutely no EQ or DSP processing other than the low end boost. Pretty cool!
I can hear the vibrating cardboard waveguide, so, that's not amazing. I'll try to dampen it a bit, but there's so much I can do with cardboard. Solid wood would be amazing, but a pain to do. 3D printing might be the way to go... There are resources online to find printers near your home... I'll check that.
Well, I must apologize...
being sick had affected my brain. When I did the first try, I set the WG convex! I guess it gave all sorts of phase issues, and created the duller sound.
Now, having re-done the WG convex, I have pin point imaging and crystal clear sound. Funny, the sweet spot narrowed a little, so having a tweet on a concave WG creates a huge sweet spot, but messes things up.
The SB65s are finally starting to loosen up, and while the string instruments are still amazing, the voices are becoming cleaner and warmer. Very lifelike.
Possible concern.... The point of the MTM is to get better vertical lobes? With the waveguide and the woofers crowding it so close, it might be worth measuring 30 degrees above and below the SB65 (or any other convenient angle if it comes to it.....
Hi all.
Still here. Just went away on a short vacation.
Off-axis measurements are coming. As soon as I get a quiet house and time to bring out the mic.
turk, I see your picture... you just have to reload the page to see your picture again... but I am more a red wine kind of guy... scotch is not my thing. Too dry!
I'm thinking of making an oval shape piece of wood, cut it into 4 parts to make the horns, mounting them on a back plate where the SB65 is screwed in.
Still here. Just went away on a short vacation.
Off-axis measurements are coming. As soon as I get a quiet house and time to bring out the mic.
turk, I see your picture... you just have to reload the page to see your picture again... but I am more a red wine kind of guy... scotch is not my thing. Too dry!
I'm thinking of making an oval shape piece of wood, cut it into 4 parts to make the horns, mounting them on a back plate where the SB65 is screwed in.
on that analogy looking at the cardboard curves and no vertical taper is reminiscent of a straight up swig of scotch while the shape of Emilar horn leads me to think that it would be more of a glass of wine complex, robust, with a nice finish...i can appreciate other libations...just thought that that style of horn mouth shape would allow for closer center to center spacing on the "racetracks".
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