I recently finished some double bass reflex enclosures for a pair of FE127E.
I'm really happy with some aspects of the sound - for example imaging and detail. However when listening to very familiar recordings I notice a slight "honky" or nasal sound, particularly to female voices. It's very subtle, and I might not be explaining it properly.
Could this be due to the enclosure? Or, is it just because my ears are used not used to full range sound? Has anyone else experienced anything like this? The FE127E is highly regarded and is meant to sound very good, so it's probably not the driver itself.
Does anyone have an idea of the frequency ranges that could cause this "honkiness"? Could it be lack of low frequencies due to a port tuning problem?
This is my first attempt at building a speaker enclosure, and I have probably caused this problem myself.
The enclosures are 16mm MDF with the internal volume as specified in the fostex plan, tightly sealed, 15mm felted wool on the rear and sides of the upper chamber, 62mm diameter ports with lengths adjusted using Ron E's formula:
http://www.diyaudio.com/forums/showthread.php?postid=926289#post926289
Regarding driver break in, I suppose the sound could change over time. But, in my experience after extensive break in the sound never changes enough to resolve something like this.
Thanks in advance for any suggestions.
I'm really happy with some aspects of the sound - for example imaging and detail. However when listening to very familiar recordings I notice a slight "honky" or nasal sound, particularly to female voices. It's very subtle, and I might not be explaining it properly.
Could this be due to the enclosure? Or, is it just because my ears are used not used to full range sound? Has anyone else experienced anything like this? The FE127E is highly regarded and is meant to sound very good, so it's probably not the driver itself.
Does anyone have an idea of the frequency ranges that could cause this "honkiness"? Could it be lack of low frequencies due to a port tuning problem?
This is my first attempt at building a speaker enclosure, and I have probably caused this problem myself.
The enclosures are 16mm MDF with the internal volume as specified in the fostex plan, tightly sealed, 15mm felted wool on the rear and sides of the upper chamber, 62mm diameter ports with lengths adjusted using Ron E's formula:
http://www.diyaudio.com/forums/showthread.php?postid=926289#post926289
Regarding driver break in, I suppose the sound could change over time. But, in my experience after extensive break in the sound never changes enough to resolve something like this.
Thanks in advance for any suggestions.
Thanks for the responses.
I'll try adding a little more absorbant material of better quality. Currently I'm using recycled wool felt. I'll try replacing it with 20mm polyester insulation which is more dense and of uniform thickness.
I see another user recommends loosely stuffing the lower chamber, I'll try that too.
You are right, lovechild. I should also be more paitent regarding break-in.
I'll try adding a little more absorbant material of better quality. Currently I'm using recycled wool felt. I'll try replacing it with 20mm polyester insulation which is more dense and of uniform thickness.
I see another user recommends loosely stuffing the lower chamber, I'll try that too.
You are right, lovechild. I should also be more paitent regarding break-in.
Fostex Driver break-in is legendary - at least 200 hrs of "rode hard and put up wet"
Try the cone treatment as described on Planet10's post - works wonders for both the 127 and 126. In my case I noticed a smoothing of midrange resonances as well as extended and tighter bass response.
FWIW, I've built a couple of Fostex recommended designs (neither of them the 127 reflex enclosures) and much preferred the performance of other designs. For a single pair of 127's, the Fonken is a giant-killer.
Try the cone treatment as described on Planet10's post - works wonders for both the 127 and 126. In my case I noticed a smoothing of midrange resonances as well as extended and tighter bass response.
FWIW, I've built a couple of Fostex recommended designs (neither of them the 127 reflex enclosures) and much preferred the performance of other designs. For a single pair of 127's, the Fonken is a giant-killer.
I agree with ChrisB on this one.
Be patient and wait for the driver to break in it does take a while.
The driver modification designed by planet10 really does make this into a different driver. Give it a go, I plan on doing the modification to mine. I heard the FONKEN on the weekend and was really impressed. In the smaller room that Chrisb has set up it had very big bass and smooth sound.
Check out the plans on the reference driver thread or on Planet10's web page.
This is a good driver and these designs can wring the sweetness out of it.
Be patient and wait for the driver to break in it does take a while.
The driver modification designed by planet10 really does make this into a different driver. Give it a go, I plan on doing the modification to mine. I heard the FONKEN on the weekend and was really impressed. In the smaller room that Chrisb has set up it had very big bass and smooth sound.
Check out the plans on the reference driver thread or on Planet10's web page.
This is a good driver and these designs can wring the sweetness out of it.
I had a similar problem with my (first and not so well built) speakers. Found out i had a bad resonance in the sidewall of the speaker, which i found by literally knocking all over the enclosure, which is actually a very easy way to find parts which have to be stiffened, need screws or more glue. Have a try, this will be easy to find out and to solve if it is there.
Good luck!
Good luck!
ow31 said:chrisB,
do you listen a fontex ?
What do you think about ?
May you give the link about the cone treatment ?
Yes a pair of Fonkens is in the stable of Fostex FR designs I get to play with .
For my money, it's the best sounding enclosure design for a single FE127 that I've heard **. Great bass performance, and less room dependant than any of the bipole MLTL variants or FE126 based horns. Of course no-one would be using them in a "bookshelf" install,
so they still need stands and the the total footprint is no less than any big floorstander. However in the right room a well executed horn i.e. Ron Clarke's A126, or the Frugelhorn, will probably have an advantage on dynamics and bass transient response)
Dave's post on the driver treatment, which he's applied to both 126 and 127 with great success:
http://fullrangedriver.com/forum/viewtopic.php?pid=4861#p4861
**(in the spirit of full disclosure, this should read "that I've built" in other words, YMMV, etc etc.
Thanks for all the tips and information. I have a lot of ideas to work with now.
And thanks for the reassurance that break in will make a difference. 200 hours!? They have been used for less than 50 hours to date.
Planet10's cone treatment looks very interesting. I'm definitely going to try it on a second pair of drivers I'll be ordering soon.
Although my first post was a little negative and the honkiness remains at this point, I'm still amazed by what these modestly priced drivers sound like! This project has really sparked my interest in full range drivers.
AJS
And thanks for the reassurance that break in will make a difference. 200 hours!?
They have been used for less than 50 hours to date.Planet10's cone treatment looks very interesting. I'm definitely going to try it on a second pair of drivers I'll be ordering soon.
Although my first post was a little negative and the honkiness remains at this point, I'm still amazed by what these modestly priced drivers sound like! This project has really sparked my interest in full range drivers.
AJS
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