Fonken for 10" Audio Nirvana?

[hebrer]

With so many people having great experience with Fonken enclosures, I wonder if anyone has built a fonken for a 10" driver. I built a back-loaded horn for my 10" Audio Nirvana speakers but they do not create the same kind of musical presence as Fostex FE127eN in Metronome cabinets. My space is limited and that may be one of the reasons (BLH are BIG and my listening position is just 6 ft away, plus WAF of these speakers went down dramatically over time when compared to Metronomes).

With so much praise for Fonkens, I think I am ready to give AN 10" cast frame another chance in either open baffle configuration or in Fonken enclosure. What I am after is ease of musical presentation, presence (including "disappearing act"). Huge bass is not a high preference for me.

Anyone has put Audio Nirvana drivers in any of the Fonken enclosures? What were your results? Any recommendations? Any plans for Fonkens for 10" drivers? Thanks for sharing. Peter

[GM]

Don't know what performance criteria Dave p10 uses, but when I 'run the numbers' using someone's WT3 woofer tester's measured specs I get a whopping 315.14 L tuned to 42 Hz for what I believe would be a super smooth sounding cab alignment in-room.

As I start shrinking it, even the mid bass begins quickly disappearing, so now Fb must rise to compensate, with 70 L tuned to Fs about the best trade-off.

All this assumes a very low output impedance amp, so should be bigger if SET driven. Anyway, curious to see what Dave suggests.

GM

[hebrer]

Hi GM,
thanks for running the numbers and giving your opinion. I am unable to measure the specs of my driver myself but perhaps could ask a friend to do it if it is critical. The speakers will be driven by either a SET with 8 Ohm output impendance or a Tripath digital amp (New MKIII Tripath TA2020 PCB 25watt Class-T amplifier | eBay).

Peter

[GM]

Greets!

You're welcome!

That much output impedance will require accurately tuning to Fs for most efficient power transfer, so will have to be done manually just like in the so called 'good old days'. The tripath amp won't care, so a lower tuning could be used and easy enough to implement by heavily stuffing or completely blocking off one or more vents.

With an effective ~ 0.803 Qts in SET mode, the 315+ L is the way to go to get any real bass and theoretically should be even bigger, but the small cab will only increase to ~90 L, although at the 'cost' of a ~2 dB peaking in the mid bass that even heavy stuffing probably can't completely flatten out, but then tube lovers tend to prefer this type of 'warm' bass response, so probably won't be an issue.

GM

[hebrer]

Hi GM,
Your input is much appreciated, but sadly I am unable to interpret it well enough to practical level. Would I be able to re-size the plans of existing Fonken plans from Dave of Planet10 based on your information? If so, is that done using specific software (I heard of Martin King's simulation software but never used it - not yet anyway)? I would not mind 2 dB peak in mid bass at all, if it means the volume can be decreased to about 90 L. Would it be wrong to simply recalculate the plans for Floorstanding Fonken MkII for the box to have internally 70 L, with all ratios kept unchanged? I should be able to do that...
Peter

[planet10]

The existing Fonken/miniOnken plans will only give an indication of the basic theme of the shape. If possible a miniOnken for the A10 will need to be done from scratch, and, as GM indicates, likely be large.

The other issue is what T/S parameters to use to detemine the box. Fortunately this kind of design is intended to be more tolerent of non-horizontal T?S curves (indicated to me, by large differences from factory (LEAP or LMS) to smallV computer measures). The other issue is potentially large unit-to-unit differences.

I can look, but not right now.

dave

[hebrer]

Hi Dave,
I realize how much DIY newbies - myself included - are dependent on your qualified opinion and I do now wish to take more of your time than is really needed - I know you already share much more of your knowledge with others than could be reasonably expected.

I wrote above that BLH for Audio Nirvana 10" that I built are proving too much (read: too big) for my listening area (and for my family - a wife and two small kids). Their volume, btw, is 210 liters (17"x18"x49", built with 3/4" BB). So I am looking for reasonable replacement for the AN 10" drivers to be used in small area (listening position 6-7 ft away from the speakers).

I wanted to consider also Fonken design but you and GM agree the volume might turn out to be greater than 200 liters, in which case this is a no-go for me. If you still think you might be able/willing to look into this, I can try and supply the T/S parameters of the particular pair of drivers that I have.
Best,
Peter

[ra7]

herber, the AN10 really calls for a back loaded horn. Don't bother with bass reflex style loading as the cabients will not only be large, but will probably never match the BLH in terms of sound.

Apart from going to a smaller driver, you can try to use a subwoofer or a pair of subs to fill in the bass and then use the AN10 in a sealed cabinet tuned to 80-100 Hz. Look to the arpeggio speaker in the articles section on diyaudio as a starting point.

[Borus]

Hay the Fonken is based on the Onken and there was a kit years ago from Focal that used a 10" driver for that system. Try to google it and I'll look for the sheet I have of the design if interested.

[planet10]

Originally Posted by ra7

herber, the AN10 really calls for a back loaded horn.

Scott & i went over ANs in horns & he figures the mass corner is too high. ie not suited to horns.

dave