Vifa TC9FD18-08 best bang for the buck

[xrk971]

Hi xrk971,
Could you recommend a design for a small fullrange bookshelf speakers (2.5-4 ltrs each) for desktop PC stereo application using a single driver vifa-tc9fd-18-08? baffle dimensions and BSC filter (if necessary) would be nice. I can make a simulation in Boxsim, but since you have measured extensively and used these beauties in all sort of cabinets and designs, that is why I am looking for a little advice from you. I dont require true Hi-Fi nor very loud listening. Something to listen to while working on pc.
reg
Prasi

If you want to get bass from the TC9, you need more volume and go with the DCR I designed. It works great as a near field monitor with reasonably low HD down to 55Hz. It is about 12 liters though.

http://www.diyaudio.com/forums/full-range/252627-viva-la-vifa-curvy-cabinet-dcr-tc9fd.html

If you really want to keep under 3 liters, go with a sealed Dagger design (3 sided tall pyramid with a trapezoidal baffle) it can be sealed or vented at the tail. It has no coloration and controlled diffraction. You will get bass down to about 150Hz.
http://www.diyaudio.com/forums/full-range/268037-fast-tl-8.html#post4192688

Similarly, a Nautaloss will sound great without coloration as well and also go to 150Hz. You will get extension below but HD starts to rise below 200Hz in a sealed.

http://www.diyaudio.com/forums/full-range/247598-nautaloss-ref-monitor.html

The Hypercube works well as a sealed too:

http://www.diyaudio.com/forums/full-range/265053-hypercube-loudspeakers-12.html#post4128571

If you really want compact bass then, you need a different driver. A 2 liter bass reflex (0.7in dia x 1.75in long vent) can be had with a Faital Pro 3FE22 cabinet down to 75Hz. I have made such a box and used a 1mH and 6R BSC for a 4in wide baffle and down firing BR port. Very compact.

No picture to show though, but here is sim with diffraction and baffle step loss and correction but far from walls.

 

[prasi]

If you want to get bass from the TC9, you need more volume and go with the DCR I designed. It works great as a near field monitor with reasonably low HD down to 55Hz. It is about 12 liters though.

http://www.diyaudio.com/forums/full-range/252627-viva-la-vifa-curvy-cabinet-dcr-tc9fd.html

If you really want to keep under 3 liters, go with a sealed Dagger design (3 sided tall pyramid with a trapezoidal baffle) it can be sealed or vented at the tail. It has no coloration and controlled diffraction. You will get bass down to about 150Hz.
http://www.diyaudio.com/forums/full-range/268037-fast-tl-8.html#post4192688

Similarly, a Nautaloss will sound great without coloration as well and also go to 150Hz. You will get extension below but HD starts to rise below 200Hz in a sealed.

http://www.diyaudio.com/forums/full-range/247598-nautaloss-ref-monitor.html

The Hypercube works well as a sealed too:

http://www.diyaudio.com/forums/full-range/265053-hypercube-loudspeakers-12.html#post4128571

If you really want compact bass then, you need a different driver. A 2 liter bass reflex (0.7in dia x 1.75in long vent) can be had with a Faital Pro 3FE22 cabinet down to 75Hz. I have made such a box and used a 1mH and 6R BSC for a 4in wide baffle and down firing BR port. Very compact.

No picture to show though, but here is sim with diffraction and baffle step loss and correction but far from walls.

Hi,
Thanks a lot. thats plenty of meat. let me chew on it a bit. but a quick question. For the Viva la Vifa, can it be made rectangular (looking from the top-like normal bookshelfs) with regular chamfer provided all around the edges? Would FR deteriorate too much? i really dont think i have the required skills to make such an elegant shape. also can i use 6mm marine plywood?
reg
prasi

 

[xrk971]

For the Viva la Vifa, can it be made rectangular (looking from the top-like normal bookshelfs) with regular chamfer provided all around the edges? Would FR deteriorate too much?

Rectangular is fine - don't worry about diffraction, even with the curved box I made, the radius of curvature is not enough to help. Flush mount your driver bezel though - that reduces some of the ripples by 1 to 2dB for free in the 600Hz to 5kHz range.

 

[prasi]

Rectangular is fine - don't worry about diffraction, even with the curved box I made, the radius of curvature is not enough to help. Flush mount your driver bezel though - that reduces some of the ripples by 1 to 2dB for free in the 600Hz to 5kHz range.

Thanks. Do you remember the volumes of upper and lower chambers that you used? I will keep the front baffle of same dimensions as that of your design and determine other dimensions based on volume of individual chambers.
Also I will be using PVC pipes for all three ports, will it create an issue? If I remember correctly, the port dia should be chosen such that its area is equal to the opening of square port, OR is there some correction factor to be applied? I seem to have forgotten everything. I will first try with suggested bsc of 1mH//10ohm// 2.2 uF.

Reg
Prasi

 

[xrk971]

On the DCR, the total volume was 12.5liters. In a DCR, the design uses a 2:1 upper:lower chamber volume ratio. Or 8.33liters top and 4.17liters bottom. The vents were 2.0 sq inches in cross sectional area x 4.7in long. The interconnect vent was reduced to 1.5in long.

Here are design details from the DCR thread:

I arrived at a design that was about 12.5 liters total volume with dual ports each having 2.0 square inches (~13 cm^2) of CSA and a vent length of 4.7 inches. The volumes would be divided using the standard DCR design practice of 2/3rds for the upper chamber (where driver is located) and 1/3rd for the lower chamber. Normally, the interconnecting port is the same length but in the model I found that reducing its length helped to smooth the response in the 150 Hz region. So the interconnecting port is the same CSA but only 1.5 in (3.8 cm) long. In order to get an approximate volume required and have curvy corners, the maximum width was set at 6 in (15.2 cm) wide.

If you use PVC pipe, you may not be able to find a pipe dia that gives 2 sq inches CSA. In which case, a simulation would have to be re-run to determine the optimal length once you figure out the dia.

 

[prasi]

On the DCR, the total volume was 12.5liters. In a DCR, the design uses a 2:1 upper:lower chamber volume ratio. Or 8.33liters top and 4.17liters bottom. The vents were 2.0 sq inches in cross sectional area x 4.7in long. The interconnect vent was reduced to 1.5in long.

Here are design details from the DCR thread:



If you use PVC pipe, you may not be able to find a pipe dia that gives 2 sq inches CSA. In which case, a simulation would have to be re-run to determine the optimal length once you figure out the dia.

I think I will be able to find 2sq.in. CSA PVC pipe (dia 1.6inch). Standard pipe with nominal size of 1-1/2 has an ID of 1.6inch. PVC and CPVC Pipes - Schedule 40 & 80
I only have to search the shops who are willing give a foot or two.

 

[citeaflorin]

Hello people, i have some test with pvc pipes, for me is very natural sound, I will trie with 2 speakers and test with long pipes, i have something similar tested with fostex103n and 6 inch speakers from philips.
Pvc pipe speakers test - YouTube

 

[Bare]

I initially built these OB's for my tc9's Worked exceptionally well (with a small Sub)
eventually proved too big for my 'puter desktop.. being always in the way. Went to these simple BR boxes which are still V Good sounding.. just a wee bit less open.
But their size doesn't annoy. I'm happy