Cheap drivers in cheap O.B. system - Page 2

Moreorless · 8th December 2012, 12:05 PM

Hi xrk971,

Thks for the smilies, ;-))

I agree with you, these little cardboard/cloth totes OB should work great with active EQ & normal or biamping.
As I explained before to Sagamotto, for the 0,7 - 0,8 QTS, if you use a single R value instead of the complex R-C-I filter, you should spare some place.
But anyway, the folding aera of the drawers I have bought, is the front face where the Aura NS6 (and tweeters) are mounted. So it should not be possible to fold them again.
We would have to create other folds and think about a new folding manner.

xrk971 · 8th December 2012, 12:09 PM

Yes, the cost of your caps and inductors is probably several times the cost of the aura drivers, and then some - so the term cheap OB may be pushing it. This is why I was wondering if going with an active x-over and bi-amping would be more economical. T-amps are cheaper than big inductors! Can you explain why you have what appears to be 2 tweeters and another driver on the top box? Can this be done with say the Aurasound in the lower box and maybe a full range like a vifa tc9fd on top? To really make system cheap, use only single low pass coil on bottom, and single high pass cap on top? That way, the costs of the cap and coils is at least less than cost of drivers.

sagamotto · 8th December 2012, 01:54 PM

Yes, I also agree, those are the biggest cap and coil I have ever seen. I have just received four t-amp the other day and was planing to use as bi amping as well. So how can t-amp be made to use for active drive? Btw, I got the lepai tda-2020+ amp from Solen, they cost less to buy then to built.

xrk971 · 8th December 2012, 02:14 PM

Quote:

Originally Posted by sagamotto

Yes, I also agree, those are the biggest cap and coil I have ever seen. I have just received four t-amp the other day and was planing to use as bi amping as well. So how can t-amp be made to use for active drive? Btw, I got the lepai tda-2020+ amp from Solen, they cost less to buy then to built.

You are on the right path with all your t-amps. Maybe use car audio crossover like this one? Amazon.com: Power Acoustik C-3184 3-Way Electronic Crossover: Car Electronics The Lepai's should work well, great amps.
The bonus with the active cross over is that you can adjust cross over points and amplitude.

sagamotto · 8th December 2012, 02:24 PM

Great suggestion, never thought of the use of car audio gear for home hifi. I will sure look into this. But look like a separate power source is require. This will definitely lower the cost of this project.

xrk971 · 8th December 2012, 02:33 PM

Couple hundred milliamps of 12v, tap it from the Lepai power supplies....

loudsubz · 3rd April 2013, 10:55 PM

How was the bass response from that small NS6? They are on sale at my local supplier and was thinking of doing 2 per side in my first experimental OB setup. I would be using an NSD1001 CD for top end as I have them lying around already.

Moreorless · 7th April 2013, 03:55 PM

Hi Loud,

as I have already explained , I find that my OB system gives good basses in domestic use, for such "small" drivers.
There are 2 mains reasons for this (see my previous threads, or explanations in the Youtube vid) :
1) the Qts value has to be higher than the original one, try to reach between 0,7 - 1,0.
2) I have also boosted the bass register with the add of the biggest open box which is filtered at about 400-500 Hz.
Because if you look at the frequency curve of Aurasound, we can see that the bass output is lower about 2 or 3 dB. Inside a car, for example, its OK, as we know that the basses are boosted with 3 to 6 dB due to the narrow volume inside a car.

Hope it helps.

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8th December 2012, 12:05 PM	#11
Moreorless diyAudio Member Join Date: Jun 2008 Location: Geneva	Hi xrk971, Thks for the smilies, ;-)) I agree with you, these little cardboard/cloth totes OB should work great with active EQ & normal or biamping. As I explained before to Sagamotto, for the 0,7 - 0,8 QTS, if you use a single R value instead of the complex R-C-I filter, you should spare some place. But anyway, the folding aera of the drawers I have bought, is the front face where the Aura NS6 (and tweeters) are mounted. So it should not be possible to fold them again. We would have to create other folds and think about a new folding manner.

8th December 2012, 12:09 PM	#12
xrk971 diyAudio Member Join Date: Oct 2012 Location: Virginia	Yes, the cost of your caps and inductors is probably several times the cost of the aura drivers, and then some - so the term cheap OB may be pushing it. This is why I was wondering if going with an active x-over and bi-amping would be more economical. T-amps are cheaper than big inductors! Can you explain why you have what appears to be 2 tweeters and another driver on the top box? Can this be done with say the Aurasound in the lower box and maybe a full range like a vifa tc9fd on top? To really make system cheap, use only single low pass coil on bottom, and single high pass cap on top? That way, the costs of the cap and coils is at least less than cost of drivers.

8th December 2012, 01:54 PM	#13
sagamotto diyAudio Member Join Date: Sep 2009	Yes, I also agree, those are the biggest cap and coil I have ever seen. I have just received four t-amp the other day and was planing to use as bi amping as well. So how can t-amp be made to use for active drive? Btw, I got the lepai tda-2020+ amp from Solen, they cost less to buy then to built.

8th December 2012, 02:24 PM	#15
sagamotto diyAudio Member Join Date: Sep 2009	Great suggestion, never thought of the use of car audio gear for home hifi. I will sure look into this. But look like a separate power source is require. This will definitely lower the cost of this project.

8th December 2012, 02:33 PM	#16
xrk971 diyAudio Member Join Date: Oct 2012 Location: Virginia	Couple hundred milliamps of 12v, tap it from the Lepai power supplies....

3rd April 2013, 10:55 PM	#17
loudsubz diyAudio Member Join Date: Dec 2007	How was the bass response from that small NS6? They are on sale at my local supplier and was thinking of doing 2 per side in my first experimental OB setup. I would be using an NSD1001 CD for top end as I have them lying around already.

7th April 2013, 03:55 PM	#18
Moreorless diyAudio Member Join Date: Jun 2008 Location: Geneva	Hi Loud, as I have already explained , I find that my OB system gives good basses in domestic use, for such "small" drivers. There are 2 mains reasons for this (see my previous threads, or explanations in the Youtube vid) : 1) the Qts value has to be higher than the original one, try to reach between 0,7 - 1,0. 2) I have also boosted the bass register with the add of the biggest open box which is filtered at about 400-500 Hz. Because if you look at the frequency curve of Aurasound, we can see that the bass output is lower about 2 or 3 dB. Inside a car, for example, its OK, as we know that the basses are boosted with 3 to 6 dB due to the narrow volume inside a car. Hope it helps.