Looking for Best driver for 5lt/.18 cu" front vent cabinet

Looking for Best driver for 5lt/.18 cu" front vent cabinet

I'm a newbie and would appreciate any help you can offer. I'm planning my own build for a 2nd room.

I've searched through the forum and could really appreciate any advice on the driver and cabinet design for my situation.

I'm looking for the best full range single driver for a front or bottom vented cabinet of approx. 5 liter/ .18 cu ft. cabinet. Price doesn't matter so much, I'll be spending a lot of time on it and want it to sound & look nice with veneer. I have the wife approval issue and need to keep cabinet small in scale. Will not be played loudly, mostly low volume.

I liked the DelSol and other similar speakers.
example 1

Example 2


nice example 3


Speaker will be for a small reading room approx. 8' ax 9'. Listening distance will be 6-7' max. They will be sitting on a very thick 6" solid Baltic birch plywood bench (16" ht.) positioned only 4" against the wall. Needs to be shielded as there is a plasma screen in the middle.

I really prefer not to have a forward/front row sound, something a bit mellower than my Totem Ones.

Read good things about the Bamboo driver. What's the latest & greatest for such a project.

Cheers,

Macgee


Photo's below from forum is another example that I like:

[IMGDEAD]http://avforum.no/minhifi/users/wmorig/b6ad1eafcb91970797fe7bca8601fd3b.JPG[/IMGDEAD]

[IMGDEAD]http://avforum.no/minhifi/users/wmorig/0fb5b98398d70127f6d6d67992573142.JPG[/IMGDEAD]
 
mr_macgee said:
Is there a link to building plans for such a speaker? 5-6 cubic liters, front or down ported.

Is there a difference in characteristics between down and front firing ports?

Cheers and thanks for the help.

Macgee


I'd guess that the speakers pictured are Fostex FE126 in the recommend BR design ( 10.5 liter / tuned to about 60Hz) - it's approx 85mm deeper than the single BR design for the FE127, 10liter / tuned to 71Hz. Both those designs are available at Madisound's website.


In theory there might be some advantages to a down firing port, if it's close enough to the floor - otherwise it simply makes for a more awkward stand mount- then of course there's debate over rear or front firing port. FWIW, I think the final arbiter of that question is the ultimate installation - many of the smaller designs might well fit on a bookshelf or table top flanking a TV screen, but performance of a rear port would be severely compromised, and a down firing port would be out of the question.


The FE126E is far better suited to a BLH design, and unfortunately those tend to be physically much bigger than either of the BR designs. Of course if you're intending to stand mount a little BR cabinet of any design, that's a moot point, as the total footprint of some small floorstander designs might not be any larger, and I dare say the performance of good examples of the latter would more than compensate for any extra floorspace. Enclosures such as the Mileva, PAWO, Brynn, BIB, etc immediately come to mind.

Box designs for many of those are available at

http://www.frugal-horn.com/spawn.html

and

http://www.zillaspeak.com/bib.asp



Having built more than a few of them myself, I can attest that there are quite a few "DIY" designs that easily outperform many of the Fostex "factory" designs, and in particular those for the FE126/127. For example, there are numerous designs posted on the Planet10 website Box Plans Library,

http://www.planet10-hifi.com/boxes-fostex.html

Of particular interest might be the Fonken family - most notably the first 2 on the list. The Fonken has already enjoyed quite a few DIY builds (aside from the 8 or so pairs I've built myself) - the total dimensions are not hugely greater than those of the factory BR, and within limits imposed by the driver's T/S parameters, the performance is quite superb.

Dave has a downsized Fonken design for FE127E, for which the drawings have not yet been published on his site - they give up some of the bass extension and articulation of the larger box, but are a substantially easier build. e-mail him at his website if interested
 
chrisb said:
a downsized Fonken design for FE127E

mFonken (milliFonken) was a stab at making the smallest possible box for the FE127. Took us 3 tries to get it right It is 4.5 liter (almost exactly the same as the BBC LS3/5A). And about the same bass extension (good to ~90 Hz).

With the necessary proximiity of the walls of the box it gives up a bit of openess compared to the larger Fonken.

Plans just need one more QC pass before they go up so i can mail the existing to anyone that wants a head start.

They are the ones in the middle.

dave
 

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On the cabinet behind the Fonken trio in Dave's picture, discerning eyes will note the latest version of CSS SDX7 mid-woofer, with optional EnABL process.

This will raise the question as to the viability of CSS FR125 in a similarly small enclosure. Aside from approx 5dB difference in sensitivity, which can be a bit of a deal breaker with low powered SET amps, and some minor differences in tonal balance, the CSS125 is a great candidate.
(smoother bass response with more gradual roll-off in an aperiodic box than BR)
 
planet10 said:


Plans just need one more QC pass before they go up so i can mail the existing to anyone that wants a head start.

They are the ones in the middle.

dave


Hi Dave & Chrisb,

First of all; I have to say thank you for all your input that you have written in the countless posts in different forums. They have been informative & useful to myself and probably countless others.

After some reading, I have a better idea what I may need but I'm still a bit lost on deciding which driver.

I'm a newbie and my first desire is sound and the idea of making the speaker. My knowledge is low in regards to speaker design and would be very happy just to find a correct driver and a good looking cabinet for me to build. Later on I hope to learn more about design. After reading the forums, It looks like I'm not alone.

I do realize putting the speaker close the rear wall is not a good thing but I'm limited to this position, Because of this I believe I would need a forward or down ported cabinet.

I'm also limited on dimensions. The width can not be more than 7", the depth no more than 9.5", the height as high as 12".

What is the largest driver I can have within those dimensions while still achieving a high quaility sound? Sensitivity is not really an issue. Does the CSS FR125 fit within these parameters? The FF85K?

I was a little confused between Fonken sizes and which drivers go with which box, I could not find dimensions for µFonken & milliFonken.

I'm really ready to pull the trigger on drivers and start cutting some Baltic Birch. Veneer will be Tineo.

Again, thanks for the help.

Cheers,

Mr_Macgee
 
mr_macgee said:
I'm also limited on dimensions. The width can not be more than 7", the depth no more than 9.5", the height as high as 12".

If one assumes 12mm (1/2") BB then you have a maximum gross internal volume of ~8.8 litres allowing for some bracing.

What is the largest driver I can have within those dimensions while still achieving a high quaility sound?

You can fit FE127e or FR125SR. What amplifier are you using (that could seriously sway the choice one way or another)

I was a little confused between Fonken sizes and which drivers go with which box, I could not find dimensions for µFonken & milliFonken.

The FE127e goes in all the Fonken boxes except for the µFonken (FF85k). The CSS FR125 goes into a miniOnken

The Fonken & miniOnken are identical except for the port heights and the shape of the internal holey brace. The GR & FS Fonkens are the same "size" as the regular Fonken but twisted into different shapes to suit different needs, (all of these have a net volume of 13 litres)

The mFonken is the smallest box i could squeeze the FE127 in (net 4.5 litres). The µFonken is net 2 litres.

I have added the preliminary plans for the mFonken & µFonken to the Fonken page (please report bugs & omissions. That and a 3D visualization for the mFonken are all that are missing from these plans)

http://www.planet10-hifi.com/fonken.html

As we have moved forward we have personally come to prefer the FR125 in a 4.5-7 litre aperiodic/resistive vent box.

dave
 
planet10 said:


If one assumes 12mm (1/2") BB then you have a maximum gross internal volume of ~8.8 litres allowing for some bracing.



You can fit FE127e or FR125SR. What amplifier are you using (that could seriously sway the choice one way or another)



The FE127e goes in all the Fonken boxes except for the µFonken (FF85k). The CSS FR125 goes into a miniOnken

The Fonken & miniOnken are identical except for the port heights and the shape of the internal holey brace. The GR & FS Fonkens are the same "size" as the regular Fonken but twisted into different shapes to suit different needs, (all of these have a net volume of 13 litres)

The mFonken is the smallest box i could squeeze the FE127 in (net 4.5 litres). The µFonken is net 2 litres.

I have added the preliminary plans for the mFonken & µFonken to the Fonken page (please report bugs & omissions. That and a 3D visualization for the mFonken are all that are missing from these plans)

http://www.planet10-hifi.com/fonken.html

As we have moved forward we have personally come to prefer the FR125 in a 4.5-7 litre aperiodic/resistive vent box.

dave


No two driver models will sound exactly alike, even in enclosures optimized for as close to identical performance as their respective T/S parameters will allow.
A perfect example is the CSSFR125 in mini-onken and the FE127E in the Fonken.

Ultimately the factor of personal preference will enter the calculus, and once you'll got a sense of yours, you need the confidence to override advice of the best intentioned arm-chair quarterbacks. That many of us have arrived at very passionate support of specific driver/enclosure combination should be no surprise, and our choices will not satisfy everyone.

FWIW, and if not already abundantly clear, my current favorites are the FE127E in any of the Fonken designs into which it'll fit, and the FF85K in the microFonken. Note that the latter definitely needs bass support in anything other than intimately near field (i.e. computer monitor) application.

Having said that, if you're willing to pay the not insignificant sensitivity penalty of the XBL motor design, for bang for the buck in the teeniest package, the newest version of FR125 in approx 5 liter resistive vent box would be pretty hard to beat.

My most recent build for those was Dave's design with the angled back and rear facing vent (array of small holes partially stuffed with resistive damping foam). He could advise if a near wall installation would be detrimental to the performance - my intuition is that an overhead boundary might be more of an issue than the rear - but I've certainly been wrong before.

[IMGDEAD]http://homepage.mac.com/tlinespeakers/FAL/images/4L-aperiodic-FR125-tn.jpg[/IMGDEAD]


If front firing ports are mandated by placement, I'd imagine the mFonken could work as well - although the tuning of port slots would likely need to be adapted. Early in the prototyping of this smaller cabinet, we played with a standard round port, and definitely preferred the sound of the slotted port - it takes only slightly more work, and actually contributes to the side to side cabinet wall bracing.
 
planet10 said:

The mFonken is the smallest box i could squeeze the FE127 in (net 4.5 litres).
I have added the preliminary plans for the mFonken & µFonken to the Fonken page (please report bugs & omissions. That and a 3D visualization for the mFonken are all that are missing from these plans)
As we have moved forward we have personally come to prefer the FR125 in a 4.5-7 litre aperiodic/resistive vent box.
dave


chrisb said:

FWIW, and if not already abundantly clear, my current favorites are the FE127E in any of the Fonken designs into which it'll fit, and the FF85K in the microFonken.
If front firing ports are mandated by placement, I'd imagine the mFonken could work as well - although the tuning of port slots would likely need to be adapted. Early in the prototyping of this smaller cabinet, we played with a standard round port, and definitely preferred the sound of the slotted port - it takes only slightly more work, and actually contributes to the side to side cabinet wall bracing.

Hi Guys,

After doing a lot of homework and looking at my current setup and the future use of these speakers for desk or in a bedroom. I've decided to go with mFonken and will order Planet 10 FE127 .

Dave thank you for posting the drawings (I had no problem opening them).

I do have an academic question to Dave and I hope my not stepping overbounds. Looking at my setup, it would be nice if the box could be narrower but I do have room for a deeper and taller box.

Looking at the mFonken drawing; Is it possible to make it narrower by 24mm by omitting the beveled front edge and eliminating the internal corner bracing and then increasing the other 2 dimensions (H" x D") in order to keep the correct volume (4.5l)? If so, how much?

I believe I calculated .6 liter lost with the narrower width that must be made up somewhere else.

I do realize the port dim. will have to be altered (increased) to keep same tuning. Holes for the internal brace will also have to be altered.

This is more academic and I'm very curious to learn if this is possible while keeping the same performance and sound. Is there a dimension ratio that must be kept? I've already found a A/B marine Baltic Birch sheet at my friends woodshop to use for the project.

Again, thank you for your help and answering my questions. Dave I will contact you about getting the drivers.

Cheers,

macgee
 
mr_macgee said:
Looking at the mFonken drawing; Is it possible to make it narrower by 24mm by omitting the beveled front edge and eliminating the internal corner bracing and then increasing the other 2 dimensions (H" x D") in order to keep the correct volume (4.5l)? If so, how much?


It is possible. An earlier iteration was narrower. But the proximity of the side walls resulted in quite a bit of reflection back thru the cone, making the skinnier box quite a bit boxier. Widening the box just a bit (about 25 mm) made all the difference in the world. A larger champher also helps make the box dissappear a bit more.

The skinner box was still good sounding -- at least until you switched to the wider box.

dave
 

germpod

Member
2006-12-16 11:25 pm
Good choice on the mFonken. I heard it last summer at the DIYfest at Daves place, and it was my favorite fe127 speaker that he had, and he had a lot of them. It may not go real low, but it had a very nice sound and HT set ups generally have a subwoofer any how.

Ed Robinson
 

otto88

Member
2007-12-05 10:39 am
planet10 said:
The CSS FR125 goes into a miniOnken


That’s the 13 Litre (0.46 ft3) near-aperiodic Bass Reflex?


planet10 said:
As we have moved forward we have personally come to prefer the FR125 in a 4.5-7 litre aperiodic/resistive vent box.

[/B]

What are the (qualitative?) differences in the resistive vent box, and the gains going to the smaller boxes, 13 > 7 > 4.5 litres?


planet10 said:
An earlier iteration was narrower. But the proximity of the side walls resulted in quite a bit of reflection back thru the cone, making the skinnier box quite a bit boxier. Widening the box just a bit (about 25 mm) made all the difference in the world. A larger champher also helps make the box dissappear a bit more.
[/B]

(The champher is the bevelling of the sides at the front?)
So widening the box makes it sound less ‘box like’/ coloured?

Thanks
 
otto88 said:
That’s the 13 Litre (0.46 ft3) near-aperiodic Bass Reflex?

Yes. We have been finding that this really needs the foam in the port slots to keep the driver under control

What are the (qualitative?) differences in the resistive vent box, and the gains going to the smaller boxes, 13 > 7 > 4.5 litres?

4.5 liter is as small as you can reasonably go, 7 litre gives more control in the bass than the larger box.

Since i posted that i have heard Calhoun and it is very good.

(The champher is the bevelling of the sides at the front?)
So widening the box makes it sound less ‘box like’/ coloured?

Yes. There is a point of diminishing returns as far as width goes.

dave
 
otto88 said:


(The champher is the bevelling of the sides at the front?)
So widening the box makes it sound less ‘box like’/ coloured?


Hello Otto,

Correct me if I'm wrong but I believe what Dave is saying is that when the box is too narrow, it has a negative effect with with the inside environment/cabinet and that is why you need to make it a bit wider and free up the driver and let it breathe with less interence from the side walls of the cabinet.
The beveling effect is for the outside environment once the sound has been expelled from the cabinet where you want less material (narrow cabinet) on either side of the driver in order not to interfere with the acoustics.

It's a tough balance.


Cheers
 
mr_macgee said:
Correct me if I'm wrong but I believe what Dave is saying is that when the box is too narrow, it has a negative effect with with the inside environment/cabinet and that is why you need to make it a bit wider and free up the driver and let it breathe with less interence from the side walls of the cabinet.
The beveling effect is for the outside environment once the sound has been expelled from the cabinet where you want less material (narrow cabinet) on either side of the driver in order not to interfere with the acoustics.

It's a tough balance.

Indeed. This explanation also has me looking at this with a slightly different perspective. Thanx. It is always nice to expand one's perspective.

dave