While your baffle step numbers are generally correct, sometimes there is more to it. Zaph got closer to 92db after baffle step with this woofer, with extension into the 30's sealed.
Last edited:
how? you referring to SB12.3 ? I saw that but TBH I thought it's just advertising.
Zaph typically does not B.S. I believe it.
I looked it up at Zaphs website. He shows a modelled SPL curve which is about 92 dB and extends to about 45 Hz (-3 dB). I don't know what drive voltage level he used for this simulation, and I was confused when I read his comment about the distance. A typical choice would be 2.83V drive voltage and 1m distance, but I don't know. Also, the model curve does not seem to include the baffle step.
I tried a quick model with the SB34NRX75-6 in a closed box. I could reproduce the 92 dB (2.83V, 1m) / 45 Hz in a 100 L box. This was into half space, ignoring baffle step! The fact that this is more than the specified efficiency of the driver might be due to a system Q > 0.7, resulting in an SPL peak centered around 55 Hz or so. While Zaphs model curve looks flat, I believe this is due to the low x-over to the midrange which helps to maintain the mid-bass at around 92 dB.
Yes, Zaph knows what he is doing. However, for quality audio, I would not design a closed box with a resonance peak (Q > 0.7) to make the bass louder.
The SB34NRX75-6 is a beautiful driver, but I don't think it's the right choice for an amplifier-friendly high-efficiency speaker with flatish "8 Ohm" impedance.
So far so good. I'd prefer if we'd focus on figuring out what type of speaker we're trying to make.
If WAF allows, that's the way to go! What would be the right compromise between WAF and woofer size? I'd like to start at the sweet spot such that the speaker would be attractive to as many builders as possible.
Thinking about it, while I presented the Monkey Coffin concept with a 10" woofer, it would easily allow for larger woofers from a technical point of view. It just makes the whole thing bigger, but it will allow deeper bass while maintaining the efficiency of the 10" setup. I'd expect the midrange/tweeter part could remain (almost) the same for 10"/12"/15" Monkey Box versions, maybe with some changes to the x-over to jive with the acoustics of the larger baffle. Given this, the Monkey Box design could start with a 10" woofer (for example) and later we could add options for 12" or 15" woofers.
Last edited:
I don't see any option to do so, the poll is closed and I don't see any edit options.
I see, you initially set a 7-day timeout for the poll. I re-opened it for you, so you should be able to make edits or reset it.
Here's a screenshot of the first poll, so we haven't lost it
Attachments
I just see that AE (Audio Elegance) has placed its midrange TD6M on their website Acoustic Elegance TD6M high efficiency midrange/midbass driver.
I did know that it exists, but now the data is also available on their web shop.
The TD6M has a sensitivity of 94.5dB @ 1m, 2.83Vrms. Looks very interesting.
There are no SPL and impedance plots on the AE site, but on demand there is more info available.
For example this TD6M midrange, combined with the Audio Elegance TD woofer TD12H and a Satori TW29BN tweeter
Acoustic Elegance TD12H - Sealed or Vented Box Applications
SB Acoustics :: SATORI TW29BN.
That 3-way has a sensitivity of 88dB @ 1m, 2.83Vrms with the 8 ohm woofer and 90.5dB @ 1m, 2.83Vrms with the 4 Ohm, sensitivity in full space.
These AE woofers have a maximum excursion of 14 mm peak. That means they play much louder at maximum excursion. About 6 dB more than most of other 12 inch woofers.
The TD12H in a 50 litres basreflex cabinet and tuned at 45Hz has a F3 around 45 Hz.
At maximum excursion it can play 117dB loud at 1m, for frequencies higher than 40Hz. Lower than 40 Hz the maximum SPL becomes lower.
AE also has the SBP woofers for closed box applications, but then the sensitivity is about 4 to 5 dB lower and the cabinet has to be larger, around 80 to 100 litres for a 12 inch, to keep the Qtc lower than 0.70, F3 around 40Hz. The SBP woofers also have an excursion of 14 mm peak.
Acoustic Elegance SBP12 woofer for Sealed Box Applications .
I have done just a quick analysis at this moment. If there is some interest for such concept, I can look in more detail.
AE drivers are not cheap, but I think with the best drivers you can find.
Paul
I did know that it exists, but now the data is also available on their web shop.
The TD6M has a sensitivity of 94.5dB @ 1m, 2.83Vrms. Looks very interesting.
There are no SPL and impedance plots on the AE site, but on demand there is more info available.
For example this TD6M midrange, combined with the Audio Elegance TD woofer TD12H and a Satori TW29BN tweeter
Acoustic Elegance TD12H - Sealed or Vented Box Applications
SB Acoustics :: SATORI TW29BN.
That 3-way has a sensitivity of 88dB @ 1m, 2.83Vrms with the 8 ohm woofer and 90.5dB @ 1m, 2.83Vrms with the 4 Ohm, sensitivity in full space.
These AE woofers have a maximum excursion of 14 mm peak. That means they play much louder at maximum excursion. About 6 dB more than most of other 12 inch woofers.
The TD12H in a 50 litres basreflex cabinet and tuned at 45Hz has a F3 around 45 Hz.
At maximum excursion it can play 117dB loud at 1m, for frequencies higher than 40Hz. Lower than 40 Hz the maximum SPL becomes lower.
AE also has the SBP woofers for closed box applications, but then the sensitivity is about 4 to 5 dB lower and the cabinet has to be larger, around 80 to 100 litres for a 12 inch, to keep the Qtc lower than 0.70, F3 around 40Hz. The SBP woofers also have an excursion of 14 mm peak.
Acoustic Elegance SBP12 woofer for Sealed Box Applications .
I have done just a quick analysis at this moment. If there is some interest for such concept, I can look in more detail.
AE drivers are not cheap, but I think with the best drivers you can find.
Paul
Last edited:
Hi end loudspekaer has f3 on 27Hz. 45 will give us quality, but there is no sense in making such a big cabinet in order to get efficiency but having no bass. F3 at 45Hz is still 45Hz and the size will not change it.
Also, for better WAF I would advise to use two 10inch woofers
I definitely support an 8ohm easy to drive load. I think extension to 35-40 hz is sufficient, 45-50hz is not enough, although I don't think 50 liters qualifies as a large cabinet either.
Hi end loudspekaer has f3 on 27Hz. 45 will give us quality, but there is no sense in making such a big cabinet in order to get efficiency but having no bass. F3 at 45Hz is still 45Hz and the size will not change it.
Also, for better WAF I would advise to use two 10inch woofers
It is a concept choice you must make, lower F3 means lower sensititvity. Or you have to choose more and/or larger drivers in a larger cabinet.
But ok good to know your feedback. If more people prefer F3 to be low, we have to design it low
.
Huh? Why?
I am sorry to say this, but size does matter (for passive loudspeakers). There are three opposing parameters in speaker design: deep bass, high efficiency, and small box. You can have two of these, but not all three of them. My earlier model run gave approx. 92 dB down to 45 Hz (-3dB) in a 30 L box with the Fane 10" woofer. Using a larger box with a suitable 12" woofer will allow the same efficiency but to a lower cutoff frequency. Sacrificing WAF (=small box) does allow lower bass.
Also, for better WAF I would advise to use two 10inch woofers
If "high WAF" is important (is it?), then, well, maybe. I am still not a fan of the dual woofer concept, as explained in post 418.
It doesn't say the poll is closed no more but there is no edit options available
maybe you can add the suggestions in post #410 to the poll ? and reset it , please
Attachments
Hi Glenn,
This Eminence driver has a fs = 41 Hz, so you cannot make a system with a F3 that is lower.
But for a system with a F3 = 45Hz, a basreflex cabinet of about 55 L and tuned at 45 Hz, it is a perfect driver.
Good video, it is all correct. They use a 30 L cabinet tuned at 47 Hz and you can simulate that F3 = 61Hz in that case.
Paul
Question is: do we really need a high efficiency speaker? That should be first question, which will determine the rest.
As for bass extension - f3 at 40Hz is a great compromise if talking about hi end design, just because it is not proving a lot information which is happening within the two lower octaves.
I have 85dB efficiency speakers and happy with them, but you may have different needs.
I just stated my personal view only
As for bass extension - f3 at 40Hz is a great compromise if talking about hi end design, just because it is not proving a lot information which is happening within the two lower octaves.
I have 85dB efficiency speakers and happy with them, but you may have different needs.
I just stated my personal view only
Yes, this looks pretty good.
With the B&C 12 BG100 you get near identical performance at 30L with the same 45hz tuning, but it does cost twice as much.
I am of the same mind as you are. I am by no means a bass head, but I sure do love proper kick and bass with seperation and impact, without needing a sub. I don't listen at concert volume, but I also am not a music in the background guy. Ok, maybe once in a while I will push the system to the limit. Glenn.
- Status
- Not open for further replies.