DIY - Active 3-Way Xover - LR 24dB/octave

bijinmb

Well-Known Member
Joined
May 1, 2012
Messages
239
Points
93
Location
Cochin
Hi FM's,

Just completed Active 3-way xover.

Specifications:

Voltage Gain: Unity
Frequency response: Within 1dB from 10Hz to 20kHz
Filter attenuation slope: 24dB/octave
Total harmonic distortion: Typically .003% at 1V RMS
Signal to noise ratio: -94dB unweighted (22Hz to 22kHz) with respect to 1V RMS
Separation between channels: Typically better than -100dB from 10Hz to 20kHz
Input impedance: 47k?
Output impedance: less than 200?


Features:

1-unit rack case
Single PC board
12V+12V 24VA toroidal transformer
Stereo module
Buffered input and output stages
Individually variable outputs (trimpots)
On-board power supply
On-board RCA connectors
Made from standard components

Moreover it won't cost much.

More information on this below link.

Silicon Chip Online - Active 3-Way Crossover for Loud Speaker Systems

Sharing few images:









 
Last edited:
Graph in this link shows model as SB25NP but this link says it is a subwoofer, however TS params are different, picture in this link and what is available on diyaudiocart does not match, only thing which match is model number.
Products - PeerlessAudio.com

I was thinking to design a 3 way using SB25NP, but got totally confused now :)
Can anyone please help?
 
Hi Aniruddha82,

Both the driver are different physically and technically it seems.

Peerless web site is not well maintained site and also their T/S parameters are not that much reliable as well IMO.

The best bet is to measure it yourself to get the most accurate data for your planned project.

Thanks,
Bijin
 
Hi Aniruddha82,

Both the driver are different physically and technically it seems.

Peerless web site is not well maintained site and also their T/S parameters are not that much reliable as well IMO.

The best bet is to measure it yourself to get the most accurate data for your planned project.

Thanks,
Bijin

I agree with Bijin here. Peerless drivers have huge variation in their TS parameters. Consider yourself lucky if you get the left and right speaker similar. I have observed over 8% to 12% variation between left and right speaker in their resonance freq, impedance and DC VC resistance too. Strangely the phase is similar in all the drivers.
Hence if you plan to build with peerless then procure atleast 4 to 6 drivers so that you can match them out.

Unfortunately peerless does not sell matched drivers at all. I have discussed this many times with Varsha Electronics but he say he does not know how to match them. Whenever possible i go with my kit to get them matched myself before procurement. He sometimes allows replacement too if not found matched. So Quality Control is upto you. Anyway the drivers are economical to buy and is good for DIYers if you are trying for the first time.

My 2 paise.
 
That's because they all have failed QC at the manufacturing stage.

Very true
basically what varsha electronics sells is all what fails in the qc department
peerless india have their factory at seepz export zone and whatever is manufactured there is not for sale in the domestic market

They must be labelling what ever drivers fail in qc as REJECTION and varsha electronics purchases the whole lot as junk
 
They must be labelling what ever drivers fail in qc as REJECTION and varsha electronics purchases the whole lot as junk
That's one way they can take any sort of material outside SEEPZ. They declare that it is junk/scrap for disposal and they transport it out all with the connivance of the SEEPZ security/customs guys. Everyone makes money and Varsha gets their drivers. UNLESS - they are getting good drivers out by this route. Highly unlikely though.
 
But IMO it does not matter for DIY builders as they are designing only for the measured driver parameter. Hence even if the drivers are not meeting the published QC that does not mean its junk. You can still build your own box with the measured parameters. If you rely on the published parameters then you are asking for trouble and there will be endless tweaks without any achievement.

Purchasing locally for a production run is ruled out as these drivers cannot follow a set design pattern and need to be voiced individually which is impossible for commercial production.
 
Join WhatsApp group to get HiFiMART.com Offers & Deals delivered to your smartphone!
Back
Top