Thanks for posting my article and also for your kind words Mr. Gill . I hope many readers and enthusiasts build the QWL project and have many enjoyable hours , months and years ahead of listening to music. I will shortly be bringing out a project using the 12" DVC subwoofer. Keep listening and watching this space...

As with any design or engineering of speaker enclosures, the performance, sound output, bass, and sub frequencies are not guaranteed. Bandpass, Sealed and Vented Designer calculate speaker parameters based on loudspeaker theory and engineering equations/principles/formulas. The calculations are used to predict loudspeaker parameters. This was noted, because not every loud speaker design will give the expected results. Dear Ashim Francis :The above is the excerpt from the AJ Designers own web page. So please use with caution and careful consideration. We at Fredo even do not guarantee results for every build made as there are many parameters that may be inadvertently missed / added by the end user. Kindly adhere to the box dimensions quoted above and also stick to good building techniques / processes to get desired results.

Sure Bhaskar, it would be alright to communicate. You can reach me at ravi.rao.kumar@gmail.com. It may also be fine to use this forum itself , so that others who are interested can also benefit, I shall let you know if I find something. Regards

Interesting question. Simple answer..no, not that we know of. However a passband design for an 8" subwoofer is a daunting task and as of yet we are looking into the possibility of a recommended design soon. Watch this space closely for designs.

Hi Bhaskar, Great work and I feel proud that you have recognised the true worth of the FREDO HIGH END products😁 I notice your broad range of musical interests.Whenever you want to listen to music at low loudness levels you need a high power bandwidth and contour the output of your preamp ot higher lows and lower mids and highs. you might need a parametric unit to achieve this. Happy listening. If you are as passionate about music reproduction you might want to look at active speakers. Just some food for thought. Regards

The 10" DVC has been mentioned as ideal for ported enclosures, having said that we are working on a recommended box dimensions or Quarter wave and Ported designs ,both Slotted and pipe ports. We will be shortly publishing these designs. Could you elaborate why you are looking to build Bandpass enclosures?

@Amanpreet Singh Rana Your sub effective impedance is 2 Ohms! I am assuming you have 4 Ohms coils. I believe the problem may be with your amp. Most high power amp's have loudspeaker protection units that sometimes cut in. This may be your problem. to verify this is the case ,keep your output power low and slowly crank up the volume till the cut off begins to happen. If you can observe the point at which this happens then you may have to adjust the protection unit to a higher power if possible , else you will have to stay below the output power where the cut off begins. Hope this helps

i have designed this box on subpro site online . I beleive this will do nicely. your comments please?