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Old 13th April 2014, 01:24 AM   #101
krafty is offline krafty  Brazil
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Hey Matthew....

I opened up that box today. My woofer is actually another Hinor woofer. It is the "8HTS500 Light". Its datasheet here..

Funny that it is already saying in the sheet that if it's sealed, I need 8 Liters. And my box has something like 19L, pointed by folk on my other thread.

I tried 22 ohms, but the piezo was left really with little treble. So I changed for 11 ohms, it was more like what I wanted, but let's just pay attention on some music for a few days. I also replaced the bipolar caps for polyesters - I used 100V caps - is that alright?.

It's funny that, before this, I would push down the medium frequencies in the hardware equalizer. After making these changes, I now actually have to bring them the mids up, because the piezo ceased to reproduce the mediums (looks like it was doing work that wasn't supposed to do). So now, with the mediums up in the equalizer, the mediums are comming out from the woofer only....

It takes a while for you to get the whole thing about this, but it is sure fun.

Still trying to figure out my connection with 4" midbass and soundcard... do I need to connect something back to the soundcard Line-In ?

About LeSon piezo place of manufacturing:
I made a mistake, so I need to stand corrected here. The piezos are made in Brazil. Both models TLX-2 and TLC-1.
What happens is that they filed a patent in USA, so they stamp that on the tweeter dome, "USA", making it easy to get into confusion.

Last edited by krafty; 13th April 2014 at 01:35 AM.
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Old 13th April 2014, 09:58 AM   #102
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Krafty ,
I am glad you are making some progress
100v rated caps are fantastic! The good kind of overkill, it should be extremely reliable Considering that 100v at 4 ohms is well over 2000 watts it can be guaranteed that everything else in your speaker would burn out or blow up (if overdriven) long before that capacitor would fail..

Both woofers are Hinor brand eh? Ok , that makes sense. I had wondered if both of your woofers were made by the same manufacturer because from the picture it looks like both of them say something like "star" on the dustcaps.
19 liters is not too big, not at all, in fact it might be a bit too small if you are trying to get better bass response out of the speaker, take a look at Mr SYSTEM7's ported box for his 8" woofer in your other discussion, he has the right idea ...This type of Box is also referred to as vented or bass reflex , even Mr Wolf_Teeth recommended it in your other discussion... However with your 8inch Hinor woofer you would need to make the ported box at least 30 liters in size to be reasonably effective .. 40 liters looks even better in my simulations ...
If you have access to a woodworking shop and you really wanted to squeeze the maximum amount of high quality bass out of your Hinor 8" woofer you could just build a "QWP" or transmission line box for it ... Your Hinor has the proper specs for such a box, and it is pretty simple to build, its basically just like a ported box with the aspect ratio stretched out to make it pipe-like or tube-like ..

However, if you are using a separate subwoofer with your living room system, none of the above really matters, you could just put the Hinor into tiny sealed boxes because your separate subwoofer would handle all of the deep bass reproduction.

Last edited by Matthew Morgan J; 13th April 2014 at 10:06 AM.
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Old 13th April 2014, 10:02 AM   #103
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Krafty , about your soundcard, when wanting to listen to sine tones and sine sweeps produced by your signal generator software there is no need to hook anything up to the input of your soundcard ... The output of your card will of course have to be connected to the input of your amp though .... This will allow you to hear the effective ranges of your different woofers and tweeters.. You should be able to hear when responses drop off or pick up, or if there is any major dips or peaks within the working range of your drivers ....


In the future when you are ready to advance to the next level you can get some software that will utilize both the output and an input of your soundcard in order to generate a signal (a sweep or maybe "pink noise") that will play through your speakers and in turn be picked up by a microphone for the purposes of producing a graph ..... I don't recommend it at this stage though because its more complicated and requires a really good measurement microphone for accuracy, but in the future when you are ready for that just look into the free software called "HOLMImpulse" ...

Last edited by Matthew Morgan J; 13th April 2014 at 10:11 AM.
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Old 14th April 2014, 01:46 AM   #104
krafty is offline krafty  Brazil
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Quote:
I contacted the guy who does the coil filters for me, and I asked about he doing a 1mH/50R filter like you said.
Erratum: The suggested value was 0,5 ohm and not 50.
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Old 14th April 2014, 02:19 AM   #105
krafty is offline krafty  Brazil
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Updating the circuit, according to recommendations.
The only doubt is the air core inductor, which I still have to buy. I am hostage of a guy who does it, I can tell you that he is charging a lot for a coil, parts-express the air cores are like one third of what he is charging.

I am still to measure the midbass so, we will see whether this inductor will be needed or 0.11mH will be fine.



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Old 14th April 2014, 02:52 AM   #106
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Yeah, the series coil on the woofer might not be needed, but if it is needed a value of .11mh (around one tenth of a millihenry) is appropriate, this one from Parts Express would work:
Jantzen 1002 0.10mH 20 AWG Air Core Inductor | 255-020

Good news though, Since we have discovered that the LeSon tweeters have an exceptionally flat impedance response the parallel resistor (which was suggested to flatten impedance) wont be necessary .. =)
If you choose to go with the cap before the resistor as shown above in your sketch the value for the cap will need to be a bit under 1uf , more like .5uf to .8uf because the cap is seeing a 26ohm load ..... If you choose to reverse the order of the cap and resistor you can switch the cap value to 4.7uf because it will then be seeing a 4 ohm load as LeSon suggests ..... The second option will be less troublesome for you since that 4.7uf cap will always see a 4ohm load no matter what value series resistor you are using .... It would allow you the flexibility to try lots of different resistor values without having to fiddle with changing the cap every time ...

Last edited by Matthew Morgan J; 14th April 2014 at 02:56 AM.
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Old 14th April 2014, 03:06 AM   #107
krafty is offline krafty  Brazil
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Quote:
Originally Posted by Matthew Morgan J View Post
Yeah, the series coil on the woofer might not be needed, but if it is needed a value of .11mh (around one tenth of a millihenry) is appropriate, this one from Parts Express would work:
Jantzen 1002 0.10mH 20 AWG Air Core Inductor | 255-020

Good news though, Since we have discovered that the LeSon tweeters have an exceptionally flat impedance response the parallel resistor (which was suggested to flatten impedance) wont be necessary .. =)
If you choose to go with the cap before the resistor as shown above in your sketch the value for the cap will need to be a bit under 1uf , more like .5uf to .8uf because the cap is seeing a 26ohm load ..... If you choose to reverse the order of the cap and resistor you can switch the cap value to 4.7uf because it will then be seeing a 4 ohm load as LeSon suggests ..... The second option will be less troublesome for you since that 4.7uf cap will always see a 4ohm load no matter what value series resistor you are using .... It would allow you the flexibility to try lots of different resistor values without having to fiddle with changing the cap every time ...
Funny that the Parts-Express coil doesn't have their resistance listed, is it something that really matter?

I will go with the cap before the resistor, and bought the following caps: 0.56uF, 0.51uF, 0.47uF and 1uF. Also got more 4.7uF to make 9.4uF in case I reverse them (am surprised now that you say 10uF is no longer the case?)

System7 seems to be not very fond of this reversion?
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Old 14th April 2014, 05:37 AM   #108
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Krafty,
That inductor at such a low value will have very little resistance, such a small amount of resistance that Parts Express doesn't even bother mentioning it, so yeah its nothing to worry about ...

The crossover point that LeSon was recommending with their sketch was approximately 8400hz (in order to knock down the bump at 5000hz) ... The gentle slope of the filter curve just flattens the tilted response nicely and still gives us strong but balanced response down to 5000hz ... So if we wanted to match the nice response curve that LeSon shows us in their spec file at various series resistance values (as you have the circuit arranged in the most recent sketch) we will have to go with equivalency capacitive values ... It is easier than it sounds though, i just generated the following list for you using winISD's simple first order crossover calculator.

8400hz 1st order high pass filter (series cap):

4 ohms ( LeSon Tweeter = 4ohm load ) : 4.7uf

Rounded equivalencies are listed below:

14 ohms (10 ohm series resistor + 4 ohm load) : 1.3uf
19 ohms (15 ohm series resistor + 4 ohm load) : 1uf
26 ohms (22 ohm series resistor + 4 ohm load) : 0.7uf
31 ohms (27 ohm series resistor + 4 ohm load) : 0.6uf
37 ohms (33 ohm series resistor + 4 ohm load) : 0.5uf



So in other words as one option you would arrange the components in the order of:
amp--> 0.7uf capacitor---->22 ohm resistor--->LeSon


When experimenting with capacitor values i would not exceed these suggested values given for each resistance because using higher cap values than what is suggested per resistor would likely just give you a big nasty bump in response around 5khz which would likely sound harsh and fatiguing to the ear so i cannot recommend that... However using a slightly lesser valued capacitor would be fine, and would just make the lower treble notes relatively quieter because you would just be raising the crossover point .....
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Old 14th April 2014, 06:10 AM   #109
krafty is offline krafty  Brazil
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Alright, so all the combinations above renders to the same sound ? Funny that I started to design the cross over as a 6000Hz 1st order... and now we're following LeSon recommendations, correct - which would be 8400Hz.

To achieve 0.7uF, I will need to pigback 3 caps... 0,1uF(63V) + 0,1uF(63V) + 0,51uF(250V). Is the voltage summed up on this layout or do I need to get equivalent voltages?
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Old 14th April 2014, 06:51 AM   #110
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Thats correct! All of those combinations produce the same sound just at different volume levels for the tweeter ... The higher resistance options attenuate or "pad" the tweeter more but still maintain the same response curve which happens to be the same exact response curve that the folks at LeSon seem to think is optimal .

Like i said you can alter that curve a little bit to suit your tastes though, one way would be to use your 0.5uf with the 26 ohm (22 ohm resistor) option ... This shifts the crossover up a bit higher which could potentially suit your woofer better if it turns out that your woofer plays well up to 6000hz or 7000hz , but you would have to verify what your woofer's upper limits really are by using your signal generator...

When paralleling or piggybacking capacitors like you are talking about the lowest voltage rating will be considered your total rating ... So in this case 63v which is still more than good enough at the low power levels that you are using ...
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