FE166E BLH problem

hajame · 16th June 2005, 02:50 PM

I have built the officially recommended back loaded horn enclosure for my Fostex FE166E drivers. I have placed sound aborbants and sand into it to tune the sound. I found that the sound changes a lot upon changing the amount of materials placed in it but I don't think it is the right sound this driver should produce.

The mid-high frequencies disperse and become muddy when the enclosure is empty. When there is sound absorbant just behide the driver, mid-high dispersion problem is improved a lot. However, the overall sound is still not clear.

I started filling sand to where the official datasheet told me(the canal below the driver). It seems to be optimum when the sand is of a certain volume but the sound is still slow, especially the bass.

Is it the "right" sound from a BLHed FE166E? Is there any better tuning recommeded?

Nelson Pass · 16th June 2005, 06:14 PM

Try varying the density of the stuffing just behind the driver.

Scottmoose · 16th June 2005, 06:18 PM

There's no right or wrong answer here sadly. I suspect you're just going to have to experiment until you hit on the sound you like. I'm a little surprised you're finding the bass slow though. A few general questions / points to suggest.

Firstly, how long have you had the drivers? The FE166E takes around 300 hours before giving its best in my opinion. (unlike cables, caps etc, drivers do require break-in time.)

Next question -is the horn exactly as per the Fostex plans? I've known people have problems when they rounded off all the 'nasty' right-angles inside the cabinets, which is a big mistake -they're part of the design.

Third question: how are they positioned in your room -against the wall, in corners or pulled out?

Fourth; how are they coupled to the floor? If you've put spikes on them, try removing them, and using a large quantity of Blu-Tak or children's play-dough or something like those to completly cover the base, and then stand them on a couple of paving-slabs (you can always pretty them up later with some veneer etc, or splash out on some marble if you're feeling rich). This makes a HUGE difference to any speaker, particularly in terms of improving the bass-weight and general claity. Spikes are generally not A Good Idea in my view -you've instantly created an open acoustic cavity under the speaker, which is exactly the reverse of what you need.

Best & good luck
Scott

weidok · 16th June 2005, 07:48 PM

Quote:

Originally posted by Scottmoose
[Firstly, how long have you had the drivers? The FE166E takes around 300 hours before giving its best in my opinion. (unlike cables, caps etc, drivers do require break-in time.)

Best & good luck
Scott [/B]

Thats correct they have to burn in for a long time
I am playing with the Fostex FE 167 E and after 150 hours
playing the sound improved..

are you using a bsc network ??

cantskienuf · 17th June 2005, 02:26 AM

Did you use birch or mdf? I used birch and took the minimalist approach to deadening - plumber's putty on the basket and wool felt on the magnet. I like the sound, but I did several months of OB break-in while slowly building the cabinets. From the wording on the instructions I didn't get the feeling that they were recommending deadening as much as saying that if you felt you must do so, do it here and there. Figured I could always re-open them to insert more, but I haven't felt a need.

hajame · 17th June 2005, 05:18 AM

Quote:

Originally posted by Nelson Pass
Try varying the density of the stuffing just behind the driver.

Quote:

Originally posted by Scottmoose
Firstly, how long have you had the drivers? The FE166E takes around 300 hours before giving its best in my opinion. (unlike cables, caps etc, drivers do require break-in time.)

Next question -is the horn exactly as per the Fostex plans? I've known people have problems when they rounded off all the 'nasty' right-angles inside the cabinets, which is a big mistake -they're part of the design.

Third question: how are they positioned in your room -against the wall, in corners or pulled out?

Fourth; how are they coupled to the floor? If you've put spikes on them, try removing them, and using a large quantity of Blu-Tak or children's play-dough or something like those to completly cover the base, and then stand them on a couple of paving-slabs (you can always pretty them up later with some veneer etc, or splash out on some marble if you're feeling rich). This makes a HUGE difference to any speaker, particularly in terms of improving the bass-weight and general claity. Spikes are generally not A Good Idea in my view -you've instantly created an open acoustic cavity under the speaker, which is exactly the reverse of what you need.

Best & good luck
Scott

1. I have had the drivers for a year. After 300 hours break-in time, I did notice the improvement--- better positioning, imaging and clearer mids and highs.

2. It is exactly that plan. Plywood is used except that the interior is lightly painted in case there is mould grown.

3. Both of the speakers are placed 1 feet in front of the back wall. One of them is a half feet away from the side wall and the other is 3 feets from the other side wall.

4. I did put spikes under the speakers. Before that, I cut some bouncing balls into half-spheres and used them as legs. Real spikes sounded better. I am removing the spikes and listening. I will report the result later.

The materials under the base that you mentioned is not avaliable to me. I think I will try using some magazines first.

hajame · 17th June 2005, 05:18 AM

Quote:

Originally posted by weidok

are you using a bsc network ??

What is a bsc network?

Josephjcole · 17th June 2005, 02:39 PM

Quote:

Originally posted by hajame

What is a bsc network?

Baffle step Compensation. I don't think you will need this, but if you want to read about it you can find it here:
http://www.t-linespeakers.org/tech/b...intro-bds.html
Joe

johninCR · 17th June 2005, 05:09 PM

The problem may be your room if you now have bass that was lacking before, and now it sounds muddy. Give them a listen outside with only a rear wall boundary. The room is often the most overlooked item but IMHO is one of the most important factors in obtaining good sound.

Nelson Pass · 18th June 2005, 03:21 AM

Quote:

Originally posted by Josephjcole
Baffle step Compensation. I don't think you will need this, but if you want to read about it you can find it here:
http://www.t-linespeakers.org/tech/b...intro-bds.html

Joe

Many of the full range / high efficiency drivers, even when they
don't need BSC as such, often benefit from some of this type
of correction. The simple truth is that a lot of them have a hot
and/or peaky upper mid and top end that is improved through
step attenuation. The FE166E is not a big offender in this
area, though.

16th June 2005, 02:50 PM	#1
hajame diyAudio Member Join Date: Jun 2005 Location: Hong Kong	FE166E BLH problem I have built the officially recommended back loaded horn enclosure for my Fostex FE166E drivers. I have placed sound aborbants and sand into it to tune the sound. I found that the sound changes a lot upon changing the amount of materials placed in it but I don't think it is the right sound this driver should produce. The mid-high frequencies disperse and become muddy when the enclosure is empty. When there is sound absorbant just behide the driver, mid-high dispersion problem is improved a lot. However, the overall sound is still not clear. I started filling sand to where the official datasheet told me(the canal below the driver). It seems to be optimum when the sand is of a certain volume but the sound is still slow, especially the bass. Is it the "right" sound from a BLHed FE166E? Is there any better tuning recommeded?

17th June 2005, 05:09 PM	#9
johninCR diyAudio Member Join Date: Apr 2004 Location: Costa Rica	The problem may be your room if you now have bass that was lacking before, and now it sounds muddy. Give them a listen outside with only a rear wall boundary. The room is often the most overlooked item but IMHO is one of the most important factors in obtaining good sound. __________________ Everyone has a photographic memory. It's just that most are out of film.

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16th June 2005, 06:14 PM	#2
Nelson Pass The one and only Join Date: Mar 2001	Try varying the density of the stuffing just behind the driver.

16th June 2005, 06:18 PM	#3
Scottmoose diyAudio Member Join Date: Mar 2005 Location: UK	There's no right or wrong answer here sadly. I suspect you're just going to have to experiment until you hit on the sound you like. I'm a little surprised you're finding the bass slow though. A few general questions / points to suggest. Firstly, how long have you had the drivers? The FE166E takes around 300 hours before giving its best in my opinion. (unlike cables, caps etc, drivers do require break-in time.) Next question -is the horn exactly as per the Fostex plans? I've known people have problems when they rounded off all the 'nasty' right-angles inside the cabinets, which is a big mistake -they're part of the design. Third question: how are they positioned in your room -against the wall, in corners or pulled out? Fourth; how are they coupled to the floor? If you've put spikes on them, try removing them, and using a large quantity of Blu-Tak or children's play-dough or something like those to completly cover the base, and then stand them on a couple of paving-slabs (you can always pretty them up later with some veneer etc, or splash out on some marble if you're feeling rich). This makes a HUGE difference to any speaker, particularly in terms of improving the bass-weight and general claity. Spikes are generally not A Good Idea in my view -you've instantly created an open acoustic cavity under the speaker, which is exactly the reverse of what you need. Best & good luck Scott

17th June 2005, 02:26 AM	#5
cantskienuf diyAudio Member Join Date: Dec 2003 Location: Denver, CO	Did you use birch or mdf? I used birch and took the minimalist approach to deadening - plumber's putty on the basket and wool felt on the magnet. I like the sound, but I did several months of OB break-in while slowly building the cabinets. From the wording on the instructions I didn't get the feeling that they were recommending deadening as much as saying that if you felt you must do so, do it here and there. Figured I could always re-open them to insert more, but I haven't felt a need.