The Bargain Hunter's subwoofer ...

[venki7744]

I hope you beveled the inside edge of the driver cutout - or doesn't it block the airflow behind the driver cone?

Not sure if this would affect airflow for large drivers. This might have an impact on airflow for smaller drivers.

Cheers,
Venki

 

[Decadent_Spectre]

How did I miss this...

I did not read the entire thread but it seems the driver and enclosure have been decided on.

Could the OP please answer the following -

Driver and quantity chosen

Alignment chosen

Internal cabinet volume

Amplifier chosen

DSP (if any) chosen

Further what are the dimensions of the room? What speakers are used? What is the response at LP? What SPL levels are desired at LP from the sub? What is the intended operating bandwidth of the sub? I read something about classical music, what other content will be played on the system?

What is the total budget?

 

[mpw]

am under the weather with all the MDF i seem to have inhaled in my excitement. So no progress today and tomorrow and maybe i will have to wait till next weekend.

:sad:

venki & keith - havent bevelled the inside edge of the driver cutout.

The driver is in my home and i used the driver drawings in the dayton spec sheet as my reference.

I plan to take the driver with me to the workshop ( its quite far away ) next time and see how it fits.

How did I miss this...

I did not read the entire thread but it seems the driver and enclosure have been decided on.

Could the OP please answer the following -

Driver and quantity chosen

Alignment chosen

Internal cabinet volume

Amplifier chosen

DSP (if any) chosen

Further what are the dimensions of the room? What speakers are used? What is the response at LP? What SPL levels are desired at LP from the sub? What is the intended operating bandwidth of the sub? I read something about classical music, what other content will be played on the system?

What is the total budget?

decadent_spectre

all you ask is in the thread

Driver - Dayton RS 265HF - 4 ohm
Plate amp - Hypex DS 4.0
DSP - none chosen
Sealed cabinet ( with an enclosure for the Hypex DS 4.0 plate amp )
Internal cabinet volume - Its 1 cu ft external volume. The MDF is 1 inch thick and front baffle is 1.5 inch thick ( used 1 inch MDF and then pasted 1/2 inch MDF.

Budget = INR 45000

Total consumed till now :-

driver = Rs 12500
Plate amp = Euro 340 = Rs 23800
Damping material ( Bitumen / foam / felt ) = approx 3000
Cabinet - Rs 6500 for the MDF sheet ( full sheet )
Cabinet making - none ( as of now ) ( a friend is helping out )
Piano Gloss Finish Paint - budget about 4000

Total = approx Rs 50000

I have no more to spend

regards

 

[Decadent_Spectre]

Could you elaborate on my other questions related to the room and design goals?

I really don't want to read 15 pages to find the information.

 

[keith_correa]

Not sure if this would affect airflow for large drivers. This might have an impact on airflow for smaller drivers.

Cheers,
Venki

I think this is the driver. Still think it's not required with a 1.5" thick baffle?

Edit: The flange is 9.5 mm thick. Eyeballing the rest of the space till the bottom of the vents: 38 mm. 1.5" = 38.1 mm. Do the math!

Damping material ( Bitumen / foam / felt ) = approx 3000

Egad!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[venki7744]

I think this is the driver. Still think it's not required with a 1.5" thick baffle?

Thanks for the image. I think the 1.5" baffle is the total thickness while the sub would be flush mounted on the inner .75" baffle only. There are two issues bevelling:

* It would make mounting the d-nut/t-nut even more difficult. This is unless you choose to leave the area where the nut goes in while bevelling.
* Would make the mounting depth (thickness of mdf left) which might make the mounting weak.

 

[keith_correa]

The flange is 9.5 mm thick. Eyeballing the rest of the space till the bottom of the vents: 38 mm. 1.5" = 38.1 mm.

And, typically one does not bevel the area where the mounting bolts fit. As far as "weakness" goes - I don't think so but that's a call mpw needs to make.Me? I would bevel it.

 

[mpw]

I plan to see how it actually fits and if it looks ok then no bevel.



Rgds

 

[Hari Iyer]

Any updates?

 

[Naturelover]

Yeah, things have gone awful quiet here

 

[GeorgeO]

Its quiet because the sound generated is at very low frequency and cannot be heard only felt hyeah:

 

[Naturelover]

Good one, George[emoji106]

 

[mpw]

sorry to keep you guys waiting

but i dont have the luxury of a predictable 9 to 5 job and weekends . I am held up due to work commitments.

The cabinet is ready but yet to be picked up.

hope things will fall in place by end of the month.

Waiting - is a not so nice experience for me as well.



regards

 

[mpw]

the cabinet is cut and ready. The bracings are made.

I need to go and stick the damping material + 3 mm felt sheet on the inside walls of the subwoofer cabinet before we lock and fit the bracing.

am running late on this project due to intense work and personal commitments.

Hope to put on the damping material and lock the bracings in place by this week and get it to a painter. I m looking at piano black glossy finish.

Will buy recron or relene ??? ( what is it ?? ) polyfill for stuffing.

I am looking of 6 meters of thin gauge speaker cable to take high level i/p from the amp speaker terminals.

some pics.

I hope my family accepts all this new furniture in the house and my sometimes crazy endeavors.

regards

 

[Hari Iyer]

This very heavy bracing reminds me of the B&W 800 series bracing. Hope you have also factored them in your volume calculation as they seem to occupy significant space inside the box.

 

[mpw]

Hope you have also factored them in your volume calculation as they seem to occupy significant space inside the box.

no i havent.

I did not expect such a heavy bracing myself though i do remember to having told my friend to use the 3/4 inch thickness for the bracing.

But i will see as we go along.. hopefully this is not a deal breaker.

regards

 

[Hari Iyer]

no i havent.

I did not expect such a heavy bracing myself though i do remember to having told my friend to use the 3/4 inch thickness for the bracing.

But i will see as we go along.. hopefully this is not a deal breaker.

regards

hmm, if you have not factored them an yet to fix them then I will suggest you to drill 2" hole in all the broader sides of the bracing, this will allow passage of air without obstruction and yet allow rigid support. I hope the over bracing does not spoil the show. Also will suggest you to not polish now, but test the speakers before polishing. If at all any modifications can be carried out without hassles.

 

[venki7744]

hmm, if you have not factored them an yet to fix them then I will suggest you to drill 2" hole in all the broader sides of the bracing, this will allow passage of air without obstruction and yet allow rigid support. I hope the over bracing does not spoil the show. Also will suggest you to not polish now, but test the speakers before polishing. If at all any modifications can be carried out without hassles.

Adding damping stuff like Polyfill would also increase the effective volume but at the cost of overall efficiency. I myself has tested this in a sealed box.

 

[mpw]

Adding damping stuff like Polyfill would also increase the effective volume but at the cost of overall efficiency. I myself has tested this in a sealed box.

venki,

can you elaborate ?

rgds

 

[venki7744]

venki,

can you elaborate ?

rgds

Adding polyfill would change the medium that sound travels from Air to something solid. So effective volume (air) is increased. I dont have any eq or formula to show this. But you can simulate the response for x kg of polyfill using Hornresp. I will attach some examples if you are interested once I reach home.

Thanks,
Venki

PS: for my testing, I added different amounts of polyfill and measured the TS specs for the system using WT2 repeated the measurement until I was able to tame the QTC to below 1 (since the sub was in a sub optimal volume already).