Hi All,
I have completed a pair of angular spiral enclosures and mounted with Hemp Acoustics FR8C.
Listen to it after run-in for 8 hours and I am still a bit dissapointed by the low frequencies and some shouting heard for high frquencies.
I would appreciate if anyone can give me some pointers on how to improve the sound?
I have completed a pair of angular spiral enclosures and mounted with Hemp Acoustics FR8C.
Listen to it after run-in for 8 hours and I am still a bit dissapointed by the low frequencies and some shouting heard for high frquencies.
I would appreciate if anyone can give me some pointers on how to improve the sound?
Attachments
http://www.hempacoustics.com/FR8C_-_Hemp_Spec_Sheet_ready.pdf
hard to see but I see a 5-10db climb past 700hz.......
shout seems to be a climb in midrange output...............
sort of like baffle step (bass seems gone compared to mids/highs).................
here are some comments on shout
"the drive unit itself is heavily modified with a unique phase plug and whizzer cone which removes the ’shout’ that Lowthers can typically display "
=======================================================================
Tannoy Mercury M2 loudspeakers
As expected, the macro-dynamics performance of the mid-high range is better, though I won't suggest to drive this speaker far too loud or it'll start to shout
=======================================================================
Visaton BG20
"it may need baffle step compensation, and with this driver, some form of EQ to tame the mids 'shout'/drooping HF response as already noted.
======================================================================
As good a job as Rethm did of reducing the infamous Lowther shout --- an upper midrange peak in the driver's frequency response
========================================================================
The phase plugs should fix it...my 206 sounded aweful with nothing there, very shouty. your phase plug looks neat.
=======================================================================
I did some more listening. As somebody said before, here in this thread without dust cup they somehow shout.
So now I painted them with one layer of dammar and put those phase plugs from the picture in.
========================================================================
I'd even read that shout can be caused by a bad enclosure......
Story on decware is you get a cheap transistor radio, set to voice at volume you listen at (from where you sit).........place radio in speaker box, then install speaker. What you hear is what is happening in the box then mixing / modulating the driver gettong back into the environment instead of vanishing into a black hole...........
some refer to it as "boxy sound" where midrange resonates in the box...........................
I dont see much damping in those boxes.................
Parallel walls are bad, and same dimensions (width = depth) is bad too.
or if you have speaker away from front wall, do you have any baffle step compensation ?
a 10 band equalizer could be a great friend for you.
and a whizzer would be nice also.
Oh, I just noticed you only have 8hrs on them, maybe sound will improve (more detail as surround/spider stretch a bit).
Oh, I also see the cone is only 9grams.....................
That is a very thin cone.
An enclosure than better disperses the back wave would be a good place to start.
Norman
hard to see but I see a 5-10db climb past 700hz.......
shout seems to be a climb in midrange output...............
sort of like baffle step (bass seems gone compared to mids/highs).................
here are some comments on shout
"the drive unit itself is heavily modified with a unique phase plug and whizzer cone which removes the ’shout’ that Lowthers can typically display "
=======================================================================
Tannoy Mercury M2 loudspeakers
As expected, the macro-dynamics performance of the mid-high range is better, though I won't suggest to drive this speaker far too loud or it'll start to shout
=======================================================================
Visaton BG20
"it may need baffle step compensation, and with this driver, some form of EQ to tame the mids 'shout'/drooping HF response as already noted.
======================================================================
As good a job as Rethm did of reducing the infamous Lowther shout --- an upper midrange peak in the driver's frequency response
========================================================================
The phase plugs should fix it...my 206 sounded aweful with nothing there, very shouty. your phase plug looks neat.
=======================================================================
I did some more listening. As somebody said before, here in this thread without dust cup they somehow shout.
So now I painted them with one layer of dammar and put those phase plugs from the picture in.
========================================================================
I'd even read that shout can be caused by a bad enclosure......
Story on decware is you get a cheap transistor radio, set to voice at volume you listen at (from where you sit).........place radio in speaker box, then install speaker. What you hear is what is happening in the box then mixing / modulating the driver gettong back into the environment instead of vanishing into a black hole...........
some refer to it as "boxy sound" where midrange resonates in the box...........................
I dont see much damping in those boxes.................
Parallel walls are bad, and same dimensions (width = depth) is bad too.
or if you have speaker away from front wall, do you have any baffle step compensation ?
a 10 band equalizer could be a great friend for you.
and a whizzer would be nice also.
Oh, I just noticed you only have 8hrs on them, maybe sound will improve (more detail as surround/spider stretch a bit).
Oh, I also see the cone is only 9grams.....................
That is a very thin cone.
An enclosure than better disperses the back wave would be a good place to start.
Norman
cjctan said:
Well, I don't know about anyone else, but I'm not all that surprised.
Re the LF, you provide no dimensions, but from the picture, that box is very unlikely to have sufficient volume to provide much LF gain. Solution is a bigger box, or a subwoofer. Also, unless they're hard up against a wall, you'll probably be loosing quite a bit through baffle-step loss -some Eq, either active or a passive BSC circuit will help a bit there.
Re the HF, the FR8c is no shrinking violet at the top end -it does have a rising response, like many FR units, so you can either toe it in heavily, Eq it flat, or insert a shelving filter to take things down a bit to your taste.
FWIW, give the drivers a few more hours to loosen up, but you should already have about 95% of the end performance.
Hi Norman,
Thank you for your reply and information!
" I dont see much damping in those boxes................."
I did not put any damping other than a piece of 5mm cork sheet on the back wall above the steps (around the back of the driver)
" Parallel walls are bad, and same dimensions (width = depth) is bad too. "
WOW! You are spot on! the width is equal to depth
which I just bindly followed the plans
" or if you have speaker away from front wall, do you have any baffle step compensation ? "
Currently no baffle step compensation. I guess i will google more on this topic.
" Oh, I just noticed you only have 8hrs on them, maybe sound will improve (more detail as surround/spider stretch a bit). "
I am keeping my fingers crossed and hope that the sound will improved, however, it needs a drastic and dramatic improvement
" An enclosure than better disperses the back wave would be a good place to start."
The back wall is already fixed onto the cabinet as the picture was taken before I sealed the back wall Therefore the current listening experience is from a pair of fully enclosured boxes.
Thank you for your reply and information!
" I dont see much damping in those boxes................."
I did not put any damping other than a piece of 5mm cork sheet on the back wall above the steps (around the back of the driver)
" Parallel walls are bad, and same dimensions (width = depth) is bad too. "
WOW! You are spot on! the width is equal to depth
which I just bindly followed the plans
" or if you have speaker away from front wall, do you have any baffle step compensation ? "
Currently no baffle step compensation. I guess i will google more on this topic.
" Oh, I just noticed you only have 8hrs on them, maybe sound will improve (more detail as surround/spider stretch a bit). "
I am keeping my fingers crossed and hope that the sound will improved, however, it needs a drastic and dramatic improvement
" An enclosure than better disperses the back wave would be a good place to start."
The back wall is already fixed onto the cabinet as the picture was taken before I sealed the back wall
Therefore the current listening experience is from a pair of fully enclosured boxes.Re: Re: Hemp Acoustics FR8C in Angular Spiral Enclosure
Hi Scottmoose, Thanks for your reply!
The dimension of the cabinet is 550mm (Height) x 320mm (width) x 320mm (depth) and I am using a 3/4" marine plywood.
I guess i will search more information on BSC circuit and try it out. May I know what is a "shelfing filter"?
I understand the new drivers needs some break-in time. As what you have said, I am expecting the sound to be close to its full potential at this point of time, therefore I am disappointed by how it sounded now.
Scottmoose said:
Hi Scottmoose, Thanks for your reply!
The dimension of the cabinet is 550mm (Height) x 320mm (width) x 320mm (depth) and I am using a 3/4" marine plywood.
I guess i will search more information on BSC circuit and try it out. May I know what is a "shelfing filter"?
I understand the new drivers needs some break-in time. As what you have said, I am expecting the sound to be close to its full potential at this point of time, therefore I am disappointed by how it sounded now.
cjctan said:
I would appreciate if anyone can give me some pointers on how to improve the sound? [/B][/QUOTE]
Hi,
I got a pair on loan from a friend, this is what I found, see attached photo. Please note the following:
1. driver mounted on an OB.
2. the FR is quite different from published FR from
manufacturer
3. I use this driver as mid range below 3.5Khz
sound good,due the Hempcone.
4. I won't use it as a full ranger, esp the top-end is erratic.
5. Costs more than the Fostex 167E or 207E
Hope this photo helps to explain what you found.
Attachments
Hmm. I make that 56.32 litres assuming those dimensions are internal, however a goodly portion of that volume will also be taken up by the internal panels. Nowhere near enough IMO for this unit. Where did the plans come from? I might be able to take a proper look at it to see what's happening (although I've got a fairly good idea as-is).
FWIW, the parallel cab. walls in this box won't be as much of an issue as it would be, in, say, a BR, given the convoluted path the airflow takes.
FWIW, the parallel cab. walls in this box won't be as much of an issue as it would be, in, say, a BR, given the convoluted path the airflow takes.
Re: Re: Hemp Acoustics FR8C in Angular Spiral Enclosure
Hi,
I got a pair on loan from a friend, this is what I found, see attached photo. Please note the following:
1. driver mounted on an OB.
2. the FR is quite different from published FR from
manufacturer
3. I use this driver as mid range below 3.5Khz
sound good,due the Hempcone.
4. I won't use it as a full ranger, esp the top-end is erratic.
5. Costs more than the Fostex 167E or 207E
Hope this photo helps to explain what you found. [/B][/QUOTE]
Hi, Thanks for the information.
Is the driver that you have from Hemptone?
In fact, I have read that the Hemp will sound very nice in OB design. I am using it in a small room which does not allow me to use OB design.
I guess I have chosen the wrong driver for my 1st pair of FR speakers
ttan98 said:
Hi,
I got a pair on loan from a friend, this is what I found, see attached photo. Please note the following:
1. driver mounted on an OB.
2. the FR is quite different from published FR from
manufacturer
3. I use this driver as mid range below 3.5Khz
sound good,due the Hempcone.
4. I won't use it as a full ranger, esp the top-end is erratic.
5. Costs more than the Fostex 167E or 207E
Hope this photo helps to explain what you found. [/B][/QUOTE]
Hi, Thanks for the information.
Is the driver that you have from Hemptone?
In fact, I have read that the Hemp will sound very nice in OB design. I am using it in a small room which does not allow me to use OB design.
I guess I have chosen the wrong driver for my 1st pair of FR speakers
Scottmoose said:
I have adopt this design from this website
http://spiralspeaker.web.fc2.com/aaaspeaker/extra/engag280z/eng-ag280z.html
There is a reference bookshelf design (Aperto) in the Hemp Acoustic website that makes me assumed that this driver can be use with small enclosure.
I thought as much.
Sure, if you can accept only moderate LF, cut-off being about 70Hz with that box.
I don't like to sound pessimistic, but I don't think there's a whole lot you're going to be able to do to improve this cabinet / driver combination -it just isn't going to work very well. Sorry. TBH, I'd probably write it off as a learning experience & get them into a more optimal cabinet design.
Sure, if you can accept only moderate LF, cut-off being about 70Hz with that box.
I don't like to sound pessimistic, but I don't think there's a whole lot you're going to be able to do to improve this cabinet / driver combination -it just isn't going to work very well. Sorry. TBH, I'd probably write it off as a learning experience & get them into a more optimal cabinet design.
I'm with Scott on this one, the HempAcoustic drivers do tend to like a fairly largish box, and when you compare it to a FE-206 there is no reason for me to not believe that a box intended for a 206 is not going to even work slightly when using the FR-8C. I'd take Scotts advice and chalk this one up to a learing experince and rebuild some cabinets better suited to the FR-8C, like the suggested BR, or even a SPAWN family member.
If space is a real issue me thinks that picking a FR system kinda defates your end goal, think about it this way, I never heard a FullRange design I liked unless it was bilut as one, and these include huge OB, Transmission lines and long horn lengths, so space is going to be your main enemy in this design arena, sad but true....
If space is a real issue me thinks that picking a FR system kinda defates your end goal, think about it this way, I never heard a FullRange design I liked unless it was bilut as one, and these include huge OB, Transmission lines and long horn lengths, so space is going to be your main enemy in this design arena, sad but true....
Re: Re: Re: Hemp Acoustics FR8C in Angular Spiral Enclosure
I got mine from Hemp Acoustics. Yes I mount this driver in an OB configuration yes it sounds nice, I use it as a 3-way speaker, x-over at 3.5K and 250Hz.
cjctan said:
Hi, Thanks for the information.
Is the driver that you have from Hemptone?
In fact, I have read that the Hemp will sound very nice in OB design. I am using it in a small room which does not allow me to use OB design.
I guess I have chosen the wrong driver for my 1st pair of FR speakers
I got mine from Hemp Acoustics. Yes I mount this driver in an OB configuration yes it sounds nice, I use it as a 3-way speaker, x-over at 3.5K and 250Hz.
Hi Guys!
Thank you all for sharing with me valuable information and experiences. I guess I will declare this project a failure mainly due to insufficient research on the drivers and enclosures.
Maybe I will buy a pair of FE206E to match this cabinet or build another cabinet (not in the near future).
Thank you all for sharing with me valuable information and experiences. I guess I will declare this project a failure mainly due to insufficient research on the drivers and enclosures.
Maybe I will buy a pair of FE206E to match this cabinet or build another cabinet (not in the near future).
Well, in volume terms the box should be OK, although all the internal panels will reduce it a fair bit.
TBH, I'm not sold on these spiral designs -you can get a better response out of a straightforward BR, so, with the possible exception of driver-control, I'm not really sure what they're hoping to gain from them.
TBH, I'm not sold on these spiral designs -you can get a better response out of a straightforward BR, so, with the possible exception of driver-control, I'm not really sure what they're hoping to gain from them.
the 206e also has a rising response and a few nasty peaks
and their published graphs arn't nearly as accurate as they should be.
http://www.madisound.com/catalog/PDF/fostexdrivers/FE206E.pdf
but many have had luck with 206e in a back loaded horn.
Norman
and their published graphs arn't nearly as accurate as they should be.
http://www.madisound.com/catalog/PDF/fostexdrivers/FE206E.pdf
but many have had luck with 206e in a back loaded horn.
Norman
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