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

Questions on Frugel horn XL slope of front face… If my normal seated ear level is around 38 inches then I would be below the on axis at 10 feet and beyond . My question is what is the benefit of having the 5 degree tilt

One does not want to be listening on axis. Even with the tilt, off-axis is less than 5° unless your ears are really low.

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You can skew the whole box 5° forward if you want to have a vertical baffle.

dave
 

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Yes I understand the horn angles would have to remain the same, my listening seat would be around 10 to 10.5 feet from the speaker and if I set up straight my ears are at 42 inches but I have a tendency to slouch on the coach which puts me at 38 to 39 inches. Even so with the current design it's 41.45 inches on axis at 10 feet so not a problem, I was just wondering if the speaker (10 p) sounds better off axis or if it doesn't make that much difference. On some of my past speaker builds with conventional tweeters a vertical shift of + or - of 6 to 8 inches was noticeable. Thanks for the quick reply good forum.
JIM
 
Jim - like I said earlier, I've not noticed an issue with driver height in the FHXL - what I didn't say is that I'm using A10P as L/C/R in a 7.1 system, and they're all at much lower than ear height when I'm slouched in my cozy lazy boy (and I'm not a tall guy) .

I guess I somehow got stuck on that 5dg slope angle from the original Tysen build a few years ago, but the compact floor-standers and centre channel have it as well.

Of the numerous designs I've built or heard with this class of drivers over the past dozen years or so, there've been none that I can think of that differ ONLY in the presence or absence of such a slope - i.e. the performance due to other enclosure design features would almost certainly swamp that from tilt alone, and I've just been too lazy to tilt any to an upright position for comparison.
 
Pulled the data sheet from Markaudio Alpair -10P and looking at spl vs freq and looking at the upper response roll off at -15 degree, so for me I like a softer top end so it will probably be a good tonal balance for me at around 10.5 feet. What I have found in 2 and 3 way systems the off axis shows up in the integration of the tweeter and mid range. It looks like a good for go on the FHXL for my use.
Jim
 
Joey & Jim, glad to help. Remember that the Alpair drivers need careful running in, they really benefit from care in the first 100 hours or so. After that they will continue to improve over the next couple of hundred of hours. Don't get too enthusiastic with adjusting the stuffing until they have a few hundred hours running; I found only very light stuffing was necessary below the driver. Take it from me, they really are worth investing time in and will reward you with excellent sound.
Hope you enjoy them.
 
I a just starting the running in process and started with 60 grams and will probably adjust after at least 200hours.

Would you have an estimate on the final volume of stuffing under the driver?

Joey & Jim, glad to help. Remember that the Alpair drivers need careful running in, they really benefit from care in the first 100 hours or so. After that they will continue to improve over the next couple of hundred of hours. Don't get too enthusiastic with adjusting the stuffing until they have a few hundred hours running; I found only very light stuffing was necessary below the driver. Take it from me, they really are worth investing time in and will reward you with excellent sound.
Hope you enjoy them.
 
I a just starting the running in process and started with 60 grams and will probably adjust after at least 200hours.

Would you have an estimate on the final volume of stuffing under the driver?
I first tried 60 grams BAF type stuffing fluffed up and held by velcro strips, too much damping, reduced to 45, then 30 gram, which still gave too much damping, so ended up using Monacor MDM-3 35mm thick pads cut to 630mm x 165mm rolled into a tube to line the throat below the driver, this leaves a small clear area through the middle. Weight is about 30grams. This suits my speaker placement and room.
 
@BIB
I have used polyfill similar to your Monacor in my first build using a dual MA CHR driver and proved to be effective in tuning the speaker. In the Philippines, we have both the loose stuff and the rolled pads. I also have used this in this XL build.

Will post the build photos as a later time.

@ChrisB
Thank for the info and it's good to know that the speaker can be re-tuned. I just have to make sure that the driver can easily be removed. As of the moment the Bezel is piston fitted on the cut out. I may make it a little loose for ease of removal for re-tuning.
 
How critical is the thickness of blue jeans cotton insulation, I can get some 2 inch thick bluejeans insulation from Home depot but not sure how consistent I can cut it to 1/2 inch. Haven't found any 1/2 in felt other than ordering a under rug felt 4 by 6 feet for $45.00.
Jim
 
Ok has any one tried using cotton batting folded up to 1/2 inch and then sewed around the edges, it comes in 100% cotton or 80% cotton and 20% polyester. What I don't know about the wool or cotton is density a requirement, or sound dreading? (This way I can get my long suffering wife involed He He).
Jim