The point I was making is the tweeter is offset from the vertical line of the mid/woofer, this will cause both vertical and horizontal lobing. Lining the tweeter with the vertical axis of the woofer removes the vertical lobes. This then has the effect of having the off axis response of the speaker uniform both sides giving a better power response. Lookup Linkwitz site for the importance inroom power repsponse.
I use Tom Chr Modulus86 amplifiers x4 to power my current OB's and I have just bought his Mod286 to power the subwoofers in my upcoming LXmini+2 build.
These are brilliant amplifiers and out perform amps costing $1000's. There have very low THD and IMD so they are very transparent.
I've tried it both ways and the difference if any is inaudible to my ears. If you offset the full range driver ( as MJK recommends ) the extra room makes sense for a tweeter location.
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Lining the tweeter with the vertical axis of the woofer removes the horizontal lobes.
Simulations are nice to tell driver location on baffle effect. However in farfield those errors are very difficult to hear, because we hear the sum of off-axis sound (listening window) and reflections.
Same goes pretty much for vertical c-c lobing effect, unless it is very bad.
No it removes the vertical lobes. I don't use simulation I use actual measurements on and off axis. With the tweeter off center the off axis left to right response will differ. It's well known speakers that have similar off axis and on axis response will sound better. Floyd Toole did a lot of this research with Harmon.
https://www.stereophile.com/content/blind-listening-harman-international
Um, not really, but I think you and him are saying the same thing anyway. Eliminating the horizontal offset makes the horizontal polar response more uniform (vs offset tweeter)... that's what you meant, right?
I'm new to OB design, but a novice to speaker diy in general. I've been discussing this type of hybrid design with my wife. I visited a local shop where a job design was setup. The first 20 seconds of music was fantastic and we were so eager to hear the full track until the drums were introduced and that's when the system collapsed... sonically that is. Flabby bass, dominant midrange, but super clear treble! To say the least we were disappointed. This experience occurred over a year ago, but the thought of how satisfying the midrange and treble just appeared in the room was very promising as a starting point to a great system if only to get bass out of the OB design! Your approach I can would fill this void. Best of both world designs. I'll be watching your progress.Here is a project I'm working on, called the BaSSlines. First is what it will look like when complete, with Lexan and laminated hardwood baffle. Second is the prototype out of mdf. Just the mid is open baffle.
OB speakers can be fantastic, even average OB's are pretty good. The secret is to match the drivers so their polar response is even and they can output enough SPL an smooth enough respone to not reuire too much high Q equalization.
So ideally use the smallest diameter driver with larger excursion.
Open baffle bass works differently that seal box as the OB does not excite room modes as much as seal subs. It just needs to be implemented correctly.
So ideally use the smallest diameter driver with larger excursion.
Open baffle bass works differently that seal box as the OB does not excite room modes as much as seal subs. It just needs to be implemented correctly.
After a long period of rest, I finally managed to bring home my new Open Baffle project with AEDipole 15 / 16R, TD8M and Beyma TPL200H speakers.
All coils from AEDipole15 are connected in parallel to get 4R. Amplification for them I do with an NCore 400.
I did some measurements (UMIK-1) in Audiolense and as you can see the low frequencies start to drop sharply from 40 Hz.
I'm curious if anyone else did measurements for AE Dipol 15 ,and what the result was.
Thank you very much .
All coils from AEDipole15 are connected in parallel to get 4R. Amplification for them I do with an NCore 400.
I did some measurements (UMIK-1) in Audiolense and as you can see the low frequencies start to drop sharply from 40 Hz.
I'm curious if anyone else did measurements for AE Dipol 15 ,and what the result was.
Thank you very much .
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I have made a baffless system with one AE Dipole 15 with coil in parallel, b&g neo8 and neo3, passive xover and UCD400 amplification. here are some measures taken with the one woofer at 2m from wall, and at an height of 5cm from the floor, with a 2nd order lowpass filter with 5.2mH and 94uF :
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Thank you , Robi , very much for your answer. In the meantime, I also spoke with John from AE, who confirmed to me what a normal 40 Hz descent is. So, I'm going to think of a subwofer. Otherwise the sound is very nice. I was especially surprised by the TPL200H (no back cover). It is so clear! And it has a very good synergy with TD8M. I cut the frequencies at 250hz-2500 in Audiolense with convolver in Roon.
Glad you are liking your TPL200H open back. Same thing here with TPL-150H open back. I noticed Spatial Audio maintains the felt in the back when using it in dipole, but I like it better without felt. How are you using your 200 OB?
I don't have a mid bass like yours, so I have put the AE to the limit, up to 1Khz an more... and they are very very good in the mid range. I can't imagine yours TD8M!
I initially wanted to go with another 2-way project.
But John from AE advised me not to go with Dipole above 350 Hz. That's why I went for the TD8M and I'm not sorry I took it.
A good thing happened two nights ago
I wanted to get to the back wires and pulled the speakers even further from the back wall. (I mean at about 1.5m) I can't tell you, what a beautiful bass appeared. I didn't make measurements, but it certainly became lower. Now the bass is present, I feel a light fist on my chest at a reasonable volume.
But John from AE advised me not to go with Dipole above 350 Hz. That's why I went for the TD8M and I'm not sorry I took it.
A good thing happened two nights ago
I wanted to get to the back wires and pulled the speakers even further from the back wall. (I mean at about 1.5m) I can't tell you, what a beautiful bass appeared. I didn't make measurements, but it certainly became lower. Now the bass is present, I feel a light fist on my chest at a reasonable volume.Very cool build!
Your response is very interesting to me. What kind of music do you listen to, and what drove the decision for the big rolloff above ~8K?
I have been prototyping some DML panels that have great response from about 60Hz to 10kHz that then require heavy EQ to cover everything above. I mainly listen to jazz fusion and funk from the 70s so generally nothing too high res. Just wondering if I should ease up on my high frequency requirements. Easiest way to check would obviously be to listen, but to my ear a flatter high end sounds better, even for older music.
John from AE told me that the TD8M goes up to 4000hz, but he recommended me to cut it to 2500hz.
That's what I did and I'm very happy with the result and it's a great synergy with the Beyma TPL200. It's the first time in recent years that I really enjoy listening to music
Thanks for your response and Congratulations.
The AEs are definitely fantastic drivers.
Im using the Dipole18 by my own.
I was just asking, because I'm still searching for the right midrange solution in my open baffles (4-way).
Having a good directivity is one of my goals. I will use a similar XO frequency to my Mundorf AMT. But I'm still not sure, which driver size I can chose without compromising the directivity.
Best regards
Matthias