Vertical stacking does indeed affect the horizontal response....it makes it wider. I have not known differently from my studies and it is what VituixCad predicts so....???
I forgot that you said that I left out too many files... I think this is the files needed. The horn is not accurate at all...I think I modelled a rectangle source mimicking the mouth dimension of the 350hz horn.
https://drive.google.com/drive/folders/1_6xflY5CZc5ptehcymLJVopgpm8IhGFD?usp=sharing
"Considering the placement constraints and overall system response will get to a better result so your ceiling will be a big factor in what works best." - Regarding the null in the TMW response....in this situation I will have 2 independent subs with dual stacked 15's....This may take care of the response null. Otherwise the TMMW has better room response...and the room is important.
I forgot that you said that I left out too many files... I think this is the files needed. The horn is not accurate at all...I think I modelled a rectangle source mimicking the mouth dimension of the 350hz horn.
https://drive.google.com/drive/folders/1_6xflY5CZc5ptehcymLJVopgpm8IhGFD?usp=sharing
"Considering the placement constraints and overall system response will get to a better result so your ceiling will be a big factor in what works best." - Regarding the null in the TMW response....in this situation I will have 2 independent subs with dual stacked 15's....This may take care of the response null. Otherwise the TMMW has better room response...and the room is important.
Last edited:
I think you might need to review your choice of sources if that's the case. Just for the sake of avoiding a spiral of 'discussion' on a basic acoustic concept, here are the normalised horizontal polars from BEM simulations of a single 15" driver and a pair of 15" drivers, mounted in an infinite baffle:
And now for the pair:
FYI/FWIW, historically, full range < ~ +/- 3 dB = 'nominally flat' has been the goal till very recent times with the advent of modern technology simply because only really keen hearing folks might notice it if prompted, so picking it out of a wide BW signal seems a bit too much to assume, especially an average adult in today's incredibly noisy world.
"I can almost imagine what it sounds like...I'm looking for a reaction I guess...like "ooo thats good" or "I wouldn't accept that".....I guess if it was unacceptable someone would warn me right?
Hello Camplo
Any DIY build is a leap of faith. Your really not going to know for sure until you actually power them up and get your room placement worked out. Of course the measurements are an important part of it, but subjectively there is a lot going on.
My own builds have certainly surprised me more than once both in good and bad ways and sometimes in ways I never anticipated.
Rob
Hello Camplo
Any DIY build is a leap of faith. Your really not going to know for sure until you actually power them up and get your room placement worked out. Of course the measurements are an important part of it, but subjectively there is a lot going on.
My own builds have certainly surprised me more than once both in good and bad ways and sometimes in ways I never anticipated.
Rob
This is what I was trying to illustrate in response to:
The plots are normalised to the zero degree aka axial response. Before you call something impossible, perhaps look at how it could be possible?
This consistent horizontal coverage is, after all, the founding principal of concert sound for the last 20 years.
Last edited:
Hmm, as you say, no need to go too deep into this....I believe you guys, first of all. I read some stuff about polar vs line array some time ago...I don't recall it saying that the horizontal polar remains unchanged. I think after so many drivers it does truly get wider. Never the less, I did reprogram the drivers produced by older versions of Hornresp and VituixCad and the TMW rooms response cleaned up. Being that the null is ceiling or possibly driver height related, it is now showing is a 4db dip instead of the dramatic null as before. Phase was a little different as well but its not like the hornresp/vituixcad created result is identical to what I have in real life. Maybe I can find a way to use the independant subs to help in this area.
Indeed and not a stretch to give RCA the nod for the original in the early? 1920s [link's dead and Google refuses to find it] with their 'full range' line array of as many 15" drivers as required to cover the entire vertical height of the screen on both sides with each on a pivot to individually point them to best overall advantage, though obviously at this late date couldn't compete with W.E.'s effort even though it was just a fraction of the total cost.
If the drivers are spaced vertically in a line then the horizontal will remain unchanged, this is not something to debate. All reputable sources will tell you the same as they have here. All competently simulated responses will give the same answer.
I have had a look. Nothing was grounded in your simulation so you were getting a DC offset, this is what was making the polar look weird.
You are simulating at 39V input but still with a 14.6dB boost on the woofer. You have set a very low 2nd order crossover which is why there is a loss that is being made up with boost. It doesn't really matter how you get the transfer function in the end but this is an odd way to do it.
I'm not sure how you created the drivers responses but they are quite unusual. There is no z offset which is not representative of reality and is one of the big limits with completely synthetic source inputs. As this is active it is not too bad as the actual offsets can be altered with delay anyway.
I would not put too much more time into this unless you can get some better data to be simulating with.
Attachments
I must be referring back to some old thoughts. If room treatment affects the timings of reflections than it must be literally getting rid of constructive/deconstructive modes at the listeners point of view....How is it that this improvement isn't a single point improvement just like DSP tweaks? If I change the timings of reflections I don't literally get rid of the modes I just move them around....Room treatment involves changing reflective phase/delay......
and damping sound energy? Is that right?.....GD seems to be the product of filter knees so I went into hornresp to play around with filters. A peak eq filter should be able to mock a room mode for single point right? The interesting thing is how a high pass filter and an additive peak filter both produce a peak in GD even though the Highpass is attenuating....A subtractive peak filter cause a Dip in GD. Interesting.
and damping sound energy? Is that right?.....GD seems to be the product of filter knees so I went into hornresp to play around with filters. A peak eq filter should be able to mock a room mode for single point right? The interesting thing is how a high pass filter and an additive peak filter both produce a peak in GD even though the Highpass is attenuating....A subtractive peak filter cause a Dip in GD. Interesting.
Happy holidays Paul....I am still waiting for that book on mastering you suggested, its been a while since I ordered actually. I've also compared the Oberton NMB600 to my unique AEtd15m's and was happy with what I discovered especially since Bjorn a highly respected Diy member, tested and advocated the same Oberton driver mid 2021 for his project as "the best woofer he'd tested" thus far....so I was happy to see better performance from the AE driver, looking at the resonances near break up and F, in the burst decay....it wasn't night day but the AE is slightly better in that aspect and had more high frequency extension, and the phase plug makes a positive difference and visually the AE appears to be made from higher quality construction....not that the Oberton is bad, rather that the AE is luxurious in a way. I do end up with a less efficient woofer due to lower sensitivity but it seems that this isn't a deal breaker for SQ in the home........................
So kudos to Acoustic Elegance! I still think the 18H+ is one of the best woofers made, period, and I really wish AE would re-introduce the AE15H+
So kudos to Acoustic Elegance! I still think the 18H+ is one of the best woofers made, period, and I really wish AE would re-introduce the AE15H+
It would appear so. You referred to this post in a deleted reply, to the post of mine you quoted from another thread
https://www.diyaudio.com/community/...w-distortion-with-a-2-way.334757/post-6867335
This post gives you the answer from Earl as to where you had misunderstood. If you have forgotten, read it a few more times until it sinks in again.
That Oberton is optimized for pro users, and for us in Europe is like ~~4x cheaper than AE (not talking about waiting time), on top of that it has expensive neo motor.
If You look through Oberton offer You can find for example nice 18B35 that is 227Eur @ https://www.lautsprechershop.de/pa/oberton_en.htm that is a bit closer to TD18H+ but it's just different driver as it's not optimized for midrange use, but rather for bass impact.
Problem with today market is that there realy is no 15" or 18" quality drivers optimized for "home" use.