Frugel-Horn XL for Alpair 10.3/10p, Fostex FF165wk, more

[JoeyGS]

During the break-in process of the FHXL, when would be the best time to adjust the stuffing for the bass response? 100hours? 200hours? 400hours?

And how would one know that you have the best bass response? Is there a simple instrument that can measure the bass response? Test tones and sound level meter can suffice?

 

[kevner1954]

ebay item #161423199751

 

[planet10]

That is more than 4x as expensive as the stuff from Bob: Creative Sound - Product Details

dave

 

[kevner1954]

and ya have to buy 2 of them unless your piecing them together. what sounds better?

 

[kevner1954]

so I bought 2 creative sound sheets $0.30 cheaper free shipping with the felt 12.xxshipping with creative ?????????????????

 

[JimM]

Break in boxes

Break in boxes 145 hours and still running, while building FHXL cabinets. Any suggestions on measuring 2.0 and 2.8 oz of stuffing? I don't have a scale that can measure that low.
Jim

 

[chrisb]

Jim- what, no digital kitchen / baking / "nutrition" scale?

 

[JimM]

Great idea I'm sure my wife needs one. Off to Amazon.
Jim

 

[JimM]

Does any know if Creative Sound is shut down for now? Also my wife is really going to love her birthday present of a kitchen scale, boy is she going to be surprised.
Jim

 

[kevner1954]

damping

just bought bluejean insulation from them

 

[JimM]

Making felt from cotton batting

Making ½ in felt from cotton batten.
Tools and materials
a. Iron
b. Tin shears
c. Tape measure
d. Cotton batting - I bought 90% cotton 10% binder from WalMart it came in 90 inch width and I bought
2 yards. About 6 folded layers is approx. ½ inch thick.
e. Spray adhesive, use in well ventilated area and wear long sleeve shirt and gloves. I used Loctite high
performance adhesive also from Walmart.

1. Cut one length at 38 inches then fold for the 8inch width until you get approx. ½ thickness then cut off
extra.
2. Iron the 8 inch wide folded up batting on both sides to form creases and compress batting.
3. Spray adhesive between folded batting.
4. Cut to size, then spray adhesive into loose folds and press batting to form felt.
5. Repeat for remainder of required felt.

 

[zman01]

JimM,

You'll find some pics of the lining and damping scheme for the FH3 here - similar for FH-XL:

http://www.diyaudio.com/forums/plan...k-mock-assembly-instructions.html#post2836344

Thanks To Chrisb and P10 for the pics.

 

[JimM]

I have the plans for FHXL, the problem was obtaining 1/2 inch cotton or wool felt. The post was to show how I used cotton batting to make a 1/2 in type of felt, the pieces are cut per the plan. The diy felt is denser than ultra bluejeans and probably less dense than wool, but I think it should work for what is intended. Thanks for the reply.
Jim

 

[kevner1954]

Dave , is it ok to round the corners on the internal piece, I see in the drawing it wasn't done??? Thanks

 

[kevner1954]

was done on my FH mk3's

 

[Scottmoose]

You can, but it's not necessary and I personally wouldn't advise it; the performance loss caused by rounding the internal edges will be minor (likely inaudible) but there are no benefits to doing so.

 

[JimM]

Can someone tell me the effects of more or less stuffing (below the driver) on low frequency response. I have looked at fh3 and this thread but have not found a answer.
Jim

 

[kevner1954]

even to roll the felt around the top of the internal board, . ?

 

[kevner1954]

to Jim M I put the same amount in the front , below the driver, as I did the V part and the bass is wonderful , but might have lessened the upper mids and high frequencies !!!I didn't play with it at all ... 30 grams each. I have the FHMK3 and am building the FHXL's

 

[hajj]

and the bass is wonderful , but might have lessened the upper mids and high frequencies !!!I didn't play with it at all ... 30 grams each. I have the FHMK3 and am building the FHXL's

Since the enclosure only affects frequencies below circa 300hz, the loss in upper mids and highs cannot be due to stuffing, those are purely driver dependent...
What you might have experienced is too much boost in the lower frequencies (due to too little stuffing beow the driver), giving you the inpression that the mids and highs were affected....