Hi Adason
the article is cool but it should talk about the sensivity of the driver, no ?
ah, not important but speed of air where the environment I live into is more 344m/s... not important in the final result though.
I like the 94 db choice for dynamic max security, it gives headroom enough and stay I think in 90% of the spl listening window most people live with in a normal home with most of nowadays compressed dynamic one can find in CDs.
the article is cool but it should talk about the sensivity of the driver, no ?
ah, not important but speed of air where the environment I live into is more 344m/s... not important in the final result though.
I like the 94 db choice for dynamic max security, it gives headroom enough and stay I think in 90% of the spl listening window most people live with in a normal home with most of nowadays compressed dynamic one can find in CDs.
Ah ok one has to find the watts he is needing in relation to the efficienty of the driver. So we don't care of the 8 W amp of the article as we don't know the driver efficienty, but the real input is one needs the Watts to reach 94 dB where stands at max most of the playbacks spl peaks ?
ah I get it : "
Then we can calculate the required electric power from acoustic power Pa and efficiency of the speakers (Eff):
P = Pa / Eff"
ok, not often we see it as 1%, but it's ok, I can math x85 or x95 🙂
ah I get it : "
Then we can calculate the required electric power from acoustic power Pa and efficiency of the speakers (Eff):
P = Pa / Eff"
ok, not often we see it as 1%, but it's ok, I can math x85 or x95 🙂
Last edited:
It was communist article, hence slightly different semantics.
Still, the point is, if at moderate level I measure 200 milliwatts on my speakers, and at peaks, the loudest i care to listen, just a watt, yet i have full dynamics allowed by my house, where is 300 watts required coming from?
I used to be soundman for company amateur music group, we played at company happy hours and celebrations, I used 5000 watts behringers just on vocals, so i know what it takes to make an event for few hundred listeners.
But at home?
I even produced live cd's from their concert. Good old times.
I have no idea why is it so hard to explain to some people, that when you apply steady state signal like pink noise at unbearably loud level, and its just one watt, why the heck you need 300 watts?
Still, the point is, if at moderate level I measure 200 milliwatts on my speakers, and at peaks, the loudest i care to listen, just a watt, yet i have full dynamics allowed by my house, where is 300 watts required coming from?
I used to be soundman for company amateur music group, we played at company happy hours and celebrations, I used 5000 watts behringers just on vocals, so i know what it takes to make an event for few hundred listeners.
But at home?
I even produced live cd's from their concert. Good old times.
I have no idea why is it so hard to explain to some people, that when you apply steady state signal like pink noise at unbearably loud level, and its just one watt, why the heck you need 300 watts?
I have the drivers and horn sourced. I am just struggling with the xover parts. I'm about to work on sourcing the xover parts again. I removed the hatchet from my scr scr scsr ee ene enn
screen, and it doesn't seem to have affected anything!😀
The biggest issue was the photo of the xover components in the shopping cart at ONE location only was in Duetch speak. Soooo that made it more difficult.
I'm going back in ... wish me luck. BTW, 560uf Electrolytic caps cost some dough.
Last edited:
Can someone please check and see if these are correct before I purchase?
Except I just changed the two 15uf capacitors to non electrolytic
Except I just changed the two 15uf capacitors to non electrolytic
You've got mail!
My part's list was a LOT more expensive. 😀
I think the electrolytic Mundorf cap in series for the woofer (560 uf) is a good point of departure to save money vs the poly caps.
My part's list was a LOT more expensive. 😀
I think the electrolytic Mundorf cap in series for the woofer (560 uf) is a good point of departure to save money vs the poly caps.
Last edited:
What a grandiose statement...
Scott I see your point regarding midrange but the obvious answer is that you don't run the woofer too high, making the drawbacks of doing so, null...The only point that sticks is the idea that an 8" can't be ran high enough to cross over properly to an AMT....That makes an 8" not optimal for this design...which is not the same as saying "an 8" woofer is an un-optimal midrange"...
Flaxxer, I don't know if you've pulled the trigger yet....But the board has pointed out 2 design flaws thus...dual tweets and an 8" being ran too high...it seems you are seeking to only run one tweeter...thats good...the flaw of running the 8" too high will definitely create problems in the polar...if I can remember correctly, it looks about the same as having un optimal center to center spacing? Or will he have a dip in the on axis FR as well, I cannot recall. I've had a 3 way with a 1" + 8" and I do recall their being a sort of midrange scoop which is basically what this design flaw sounds like depending on how severe...It can be corrected using DSP but it becomes a single listening point correction. Its only a deal breaker depending on how serious you are about sound quality. Thats your call. I see people crossing 1" drivers to 15" on some of the Fb boards...I know that it is a bad choice but not everyone needs/wants to achieve the highest levels of SQ? This is where I was saying the board can be your friend...You could easily lower the woofer size to compliment the needed XO point for your chosen tweeter and then configure it as a MTM section to get the most surface area for the spectrum.
Question, What is going to be Flaxxers likely lowest XO point running an AMT tweeter?
Other options, mounting the Amt in the middle of another woofer? If its a closed back, that could fly with some intelligent design...I really like AMT tweeters myself...
More questions, You say that compression drivers are missing the air you want to keep in your design...how sure are you about that? Have you heard what the board would call some of the best 1" exit compression driver set ups? I'm sure it will be within your price range....I almost cancelled a compression driver in my design after I played some electronic music on the Altecs that initially had me falling in love....I then went to Guitar center and had my faith restored after hearing more modern compression drivers with small exits. I think the saying is, Don't throw the baby out with the bath water lol
even more important...though it may cost more, are you really not digging dsp? Yeah you have to buy separate amps for each frequency section, but the freedom it provides, as well as having some supposed advantages towards SQ. Its the new standard...I call passive XO's vintage technology. I got banned from a Fb group for it once, but I was unbanned eventually lol.
Last edited:
I went with your suggestions, outside of the $120 pair of E caps from Mouser.
I already found the exact air coils used in the original, and they specd like the ones you suggested... with the exception of the 2.20mh , 1.40 ohm. That seems to be a Jantzen ...
UPDATE ... I just ordered the above Jantzen mentioned.
I guess persuasion has left the building lol! On the flip side, I think you'll find an 8" + 15" to dynamic if never having this much sd before...I predict a sort of midrange dip in the response due to the crossing the 8" so high (whats the XO point?) but it should get you by for as long as you find it tolerable? =)
Also, you can reuse your woofers when you choose to try out a compression driver on a horn or have guide.
maybe one day youll come across a jbl m2 or similar, to audition...beware, once you hear it...you can't unhear it, once you go home your system, you'll remember... XD
Also, you can reuse your woofers when you choose to try out a compression driver on a horn or have guide.
maybe one day youll come across a jbl m2 or similar, to audition...beware, once you hear it...you can't unhear it, once you go home your system, you'll remember... XD
Last edited:
BELOW ... 😀 I'm thinking this Beyma TPL150 the Horn only, and a Dayton AMTPRO4 ? That should go handily to an 8" at 2000, right? For only a 7 to 8 ft listening distance?
Well, even if we could lower the crossover point (with no ill effects to drivers) - then it becomes about the crossover character. DSP active: no problem, passive though: quite likely a problem.
THEN there is that ability to provide low-level detail, and while there are a few 8" drivers that do this well - most do not.
Ironically, one of my favorite drivers in this capacity (with very particular loading) is the Fostex 206En - an 8" driver.. but only up to about 900 Hz (..300 to 900 Hz is excellent). Off axis this "8" is a little more "omni" high up - to about 1.5 kHz, the problem is that the surround creates a substantive "dip" in freq. centered at about 1.3 kHz with a resulting 2nd order non-linear distortion "peak". Still, it can be used as high as 1.5 kHz to excellent effect.. but that's not 2 kHz.
Last edited:
Yes perhaps the images were not explained well enough
The vertical has lobes due to the length but the horizontal of a single ribbon doesn't
When you add two side by side you then get lobes in both the horizontal and vertical
Just to be clear (as my post prompted camplo's comment) I was not intending to be critical of dave123 or his design, only to show the effect of having two drivers side by side as I find data to be more valuable when it's available.
I also found this video from Harbeth to be quite interesting in relation to amplifier power requirements
how-much-amplifier-power-do-i-really-need - YouTube
I can promise you I never misread anything on purpose. I just think we have different view on things. The math shown that call BS is correct. Do you need 160 to 300 watt? Most likely not most of time, but some high quality classical recordings then definatly yes.
Last edited:
Adason has shown his working and assumptions. Although he has made no effort to understand what he labelled BS we more open minded chaps probably shouldn't do likewise. He has dropped the requirement for high fidelity (i.e. the direct sound at the listening position follows the input signal) and instead approached it from what does it take to make my hi-fi loud in my room.
It is not an unreasonable thing to do. One of the consequences of looking at things like this is that high efficiency speakers at the same average SPL will tend to sound more "dynamic" as the fidelity of the direct sound is improved. This has some relevance for the OP even if the various methods of calculation don't.
Last edited:
What are the crossover frequencies?? 220uF and 560uf values seem high. I can see 56uf and parallel caps for 44uf values.
Rob🙂
Rob🙂
The two 220uF in parallel is a part of the impedance flattening circuit and the 560uF is to protect the woofer against overexcursion or to obtain a desired box Q, I guess.
What you are saying makes sense. I was thinking along the same lines. I just have never seen values that high?
Rob🙂