Welcome to the Fi Audio HT Forum

**Fi Audio** · **09-12-07, 03:07 AM**

Thanks for stopping by the Fi Audio home theater forum and a big thanks to all at the Home Theater Shack for giving us a second home.

Just a brief introduction to what Fi is and what we do... We are a small company that does things a little differently. While we don't have hundreds of speakers sitting on pallets in a warehouse, we do hand craft each sub per order. Coupled with our CNC and manual machines we can custom build and tailor our products to closer fit your specific needs. Although we do have "standard" lines, they all have certain options that make them better suited for different tasks. We make drivers from ultra high end home audio applications to 180dB car audio monsters, from industrial noise abatement to concert pro-sound... we have flexible platforms and solutions to meet most needs.

As each driver is made to order we normally have a 2-5 business day lead time on driver production. A good portion of this is based off of your options as additional machining increases lead times. We strive to keep lead times as short as possible and still offer you a truly customizable product.

This forum will be a sounding board for Fi home audio applications and become a knowledge base for all the different options that we have. In turn we hope that our customers will share their product choices, applications, and experiences with others.

Please check out our website at www.FiCarAudio.com and if there is anything I can help with, please let me know.

Thanks,
Scott

**WillyD** · **09-12-07, 05:37 PM**

Welcome Scott! It is really nice to have Fi Audio as a part of the Shack.

**Mike P.** · **09-12-07, 07:24 PM**

Hi Scott. It's great to have you here. I'm looking forward to the Fi Audio HT Sub designs.

**Geoff St. Germain** · **09-12-07, 07:39 PM**

Welcome to the Shack. I've been very interested in your drivers, especially since I heard that you customize some specs of your drivers to tailor them more toward home use. Could you describe what you change on the drivers to tailor them for home use?

**Fi Audio** · **09-13-07, 12:23 AM**

Thanks for the welcome

As far as what we can do for the drivers, for the SSD and Q line we have been doing many IB setups. The changes are to the suspension (being softer), the coil (usually customers want a single coil in 2 or 4 Ohm for ease of wiring), and machining the gaps a little wider to adjust the Qts.

For standard HT use, we can soften the suspension a little (since most are setup for car use in the first place) depending on power, enclosure size, and tuning. Use a different dustcap to increase or decrease moving mass vs the standard version. And more recently for the 18" drivers (which seem to be the most popular sellers) use a new cone/compound that decreases moving mass by about 70 grams over the standard cone.

I am currently testing 2 new IB specific subs. First is a 15" with good efficiency, low Fs, 24mm of Xmax (suspension limited), and approx 300W rating (to get to Xmax at 20Hz). The second is a new 18" the uses a smaller, tighter motor than the Q, a 2 layer coil, 30mm of Xmax, lighter new cone, 600W rating (to get to Xmax at 20Hz). Both will have very reasonable price points, and will have special HTS pricing.

I am also doing a few more tweaks to the Q series with a different single 4 Ohm 2 layer copper coil (most of our subs use aluminum coils) that has simialr specs to the standard version, but a lower qts.

We are constantly tinkering and trying new things. When something seems useful, we will post it up. Ill be working on some stickies for the forum over the next few weeks for what HT specific tweaks and subs we have available.

Thanks,
Scott

**Geoff St. Germain** · **09-13-07, 12:46 AM**

Cool stuff! Thanks for the information Scott.

**bobgpsr** · **09-13-07, 08:56 AM**

Quote:

Fi Audio wrote:

The second is a new 18" the uses a smaller, tighter motor than the Q, a 2 layer coil, 30mm of Xmax, lighter new cone, 600W rating (to get to Xmax at 20Hz).

Are you going to use any special technology to linearize the BL? Like LMT, XBL^2, shorting coils, etc?

Thanks for catering to the home DIYers.

**Fi Audio** · **09-13-07, 10:11 AM**

Bobgpsr...
Thats a good question... and Im really not sure. I have been using XBl since its inception and have built many different subs and drivers with it. I know that tech VERY well and was licensed to use it for a long time. LMT is a TC proprietary tech, so its not something Ill use. For the past couple of years I have been using the split coil approach to linear BL in subs and mids. Works as good as anything else... but even with that I have found that many people do not like the sound of a linear BL motor (but it seems on mids/midbass most prefer it). For subs it looks good on paper, but just not to many peoples ears (Ive done AB testing and 80% of people seem to like a LGLC (long gap, long coil) better).
I will continue to design drivers with linear BL motors, but mostly for OEM. I have several motor/driver designs collecting dust with it, but Im not sure if they will ever see the light of day.
As for a shorting coil (to be powered at the same time) I have never used in production, only in testing. I have and currently use shorting rings as well as a secondary wind on the voicecoil for adjustment as well. I may impliment a couple more tricks in the HT only stuff shortly.

Thanks,
Scott

**bobgpsr** · **09-13-07, 03:45 PM**

^^^ Sorry I meant to say shorting ring, not coil. Forgot about the split coil tech. Thanks for the quick reply.

Curious that listeners don't prefer linear BL sub motors? Doesn't linear BL for the big excursions reduce distortion? Is the "sound" that they like having more harmonics seem to be fuller bass?

If this topic goes on too long, it will warrent a technical thread all by itself.

**anidabi** · **09-14-07, 07:11 AM**

Quote:

Fi Audio wrote:

I am currently testing 2 new IB specific subs. First is a 15" with good efficiency, low Fs, 24mm of Xmax (suspension limited), and approx 300W rating (to get to Xmax at 20Hz). The second is a new 18" the uses a smaller, tighter motor than the Q, a 2 layer coil, 30mm of Xmax, lighter new cone, 600W rating (to get to Xmax at 20Hz). Both will have very reasonable price points, and will have special HTS pricing.

More xmax than the drivers you are selling now? I guess there will be also Q18 with 30mm xmax with no IB tweaks?

One more thing. Are these two new drivers completely new or just minor tweaks to the existing ones?

**Fi Audio** · **09-16-07, 12:58 PM**

They are new. New motors, coils, and some other parts as well. The coil for the 30mm IB 18 will not be applicable to the Q... so we wont have the extra 2 mm available for them... nor would it be noticed

But, we figure that with where we are trying to place both of these price wise, that we will sell very few modded Qs for IB after that.
More info and some pics in a few days.

Thanks,
Scott

**John Simpson** · **09-16-07, 07:06 PM**

Welcome to the madhouse Scott! Great to see your section up and running.

As you may have heard, Australia's now at a bit lacking for IB drivers, since our local distributor of Venoms decided to stop importing them. Any plans to establish a distributor in Australia? Or do you have a ready-reckoner of postage costs for Aussie buyers?

Thanks!

**Blaser** · **09-16-07, 07:16 PM**

Wellcome Scott!! I am pretty sure you will have something to add to the HT world....

Good luck!

**joetama** · **09-16-07, 08:05 PM**

Good to see you some where other than a car audio forum...

Looking forward to what you can bring to the Home Audio world after using your products in the car audio world...

**SteveCallas** · **09-17-07, 12:30 AM**

Quote:

bobgpsr wrote:

Curious that listeners don't prefer linear BL sub motors? Doesn't linear BL for the big excursions reduce distortion? Is the "sound" that they like having more harmonics seem to be fuller bass?

Yep, it's the same reason why some prefer the sound of a sealed sub using the same driver and why you'll see a few Avalanche 18 LLT owners at a different forum wanting to build dedicated sealed subs for the 50-120hz range - they favor the artificial oomph or kick that comes along with higher distortion. The car or club bass sound is what they are after, as most people don't really get exposed to clean bass in life. They get used to the artificial oomph and that's what they take a liking to.

**WillyD** · **09-17-07, 01:03 AM**

Quote:

bobgpsr wrote:

^^^ Sorry I meant to say shorting ring, not coil. Forgot about the split coil tech. Thanks for the quick reply.

Curious that listeners don't prefer linear BL sub motors? Doesn't linear BL for the big excursions reduce distortion? Is the "sound" that they like having more harmonics seem to be fuller bass?

Its not as simple as Steve says it is.

As someone told me once "Bl non-linearity isn't the only reason for distortion."

**09-17-07, 07:41 AM**

Welcome to the Shack. Great to hear of new folks sharing their products, experiences and give-aways. Keep up the good work and we are eager to hear more from you in the up in coming months and years ahead.

jtmj

**Fi Audio** · **09-17-07, 09:38 AM**

joetama... I spend more time designing home audio equipment for OEM and striaght consulting work than car audio by far. Not too mention home audio is MUCH more straight forward (I dont have to take into account people thinking they can strap 2000W to a 300W sub and still have it live after that). But, I do have to spend a good deal of time on the car forums as two of the companies I own are car oriented.

WillyD... you are correct, but BL nonliniearity does account for the biggest portion of it. Knocking that out of the equation (within specific limits) does make a huge difference. Of course that is within reason... having a motor with 30mm of completely flat BL in each direction doesnt matter if you only have suspension that goes to 10mm. It seems to account for about 2/3 of things.

John Simpson... I do have a good friend in NZ that will be handling things both there and AUS for Fi and Ascendant Audio. It might make shipping cheaper to piggy back the home audio orders on their pallets, but I doubt at this time that we will have him stock anything HT specific. For the 18s, shipping via the postal service (by far the least expensive air shipping) looks to be between $95-115 extra per sub. Ill see where the break would be for a pallet vs just air shipping drivers. It might not be that many if the majority of people that wanted them where near a major port. Just guessing, I would say that at about 6 speakers it would become cheaper via a pallet and ocean freight. It would just take 3-4 weeks vs 5-10 days.

Thanks,
Scott

**joetama** · **09-17-07, 10:00 AM**

Quote:

Fi Audio wrote:

joetama... I spend more time designing home audio equipment for OEM and striaght consulting work than car audio by far. Not too mention home audio is MUCH more straight forward (I dont have to take into account people thinking they can strap 2000W to a 300W sub and still have it live after that). But, I do have to spend a good deal of time on the car forums as two of the companies I own are car oriented.

Thanks,
Scott

Oh indeed Home Audio is much more straight forward than car audio. Just visit Ca.com, which I know you do lol...

Anyway, just out of curiosity, are you planning on designing/releasing any mids for HA? I know you have been working with AA and have heard you have done some work on the Poly mid.

**SteveCallas** · **09-17-07, 07:17 PM**

Quote:

Willy wrote:

Its not as simple as Steve says it is.

As someone told me once "Bl non-linearity isn't the only reason for distortion."

Right.....wasn't I that someone?

**Ilkka** · **09-17-07, 07:36 PM**

Quote:

SteveCallas wrote:

Yep, it's the same reason why some prefer the sound of a sealed sub using the same driver and why you'll see a few Avalanche 18 LLT owners at a different forum wanting to build dedicated sealed subs for the 50-120hz range - they favor the artificial oomph or kick that comes along with higher distortion. The car or club bass sound is what they are after, as most people don't really get exposed to clean bass in life. They get used to the artificial oomph and that's what they take a liking to.

Higher distortion in the 50-120 Hz range can't be the reason for favouring sealed subs because smaller sealed will have more sensitivity/output (not much but 0.5-1 dB) than larger sealed/ported and therefore has less distortion in that range. Below ~40 Hz that would be correct.

I haven't measured an AVA 18" or 15" but I'm pretty it's pretty similar to the MK1 Tumult when it comes to distortion figures, meaning quite high upper bass distortion. It doesn't have a shorting ring? And only 8" spider?

More about the XBL^2 in a few days... Before that a rhetorical question: did Adire Audio ever provide even a single real world measurement that the XBL^2 reduces distortion? If they did, please show it to me.

**WillyD** · **09-17-07, 07:41 PM**

Quote:

SteveCallas wrote:

Right.....wasn't I that someone?

You'd like to think so.

But no, it wasn't you.

**Mike P.** · **09-17-07, 07:57 PM**

Quote:

Ilkka wrote:

More about the XBL^2 in a few days... Before that a rhetorical question: did Adire Audio ever provide even a single real world measurement that the XBL^2 reduces distortion? If they did, please show it to me.

The only information Adire released about XBL and distortion is here.

http://www.adireaudio.com/Files/XBL2DetailsPaper.pdf

On the second page of this PDF.

**Ilkka** · **09-17-07, 08:02 PM**

Quote:

Mike P. wrote:

The only information Adire released about XBL and distortion is here.

http://www.adireaudio.com/Files/XBL2DetailsPaper.pdf

On the second page of this PDF.

Yes I have seen those. But I'm pretty sure those are just simulations based of the fact that it has a flatter Bl curve.

I'm after some real world distortion measurements, not simulations.

**Mike P.** · **09-17-07, 08:09 PM**

Quote:

Ilkka wrote:

Yes I have seen those. But I'm pretty sure those are just simulations based of the fact that it has a flatter Bl curve.

I'm after some real world distortion measurements, not simulations.

That you won't find. We'll have to wait of your measurement of the SDX15. I'm looking forward to that.

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