Re: news from nowhere
Hi Lon, I believe it was the Bink CD and you have to print out the "Using the Bink AudioTest CD" document and tape it to the wall or something. Here's the site:
http://binkster.net/extras.shtml
Buenos suerte, amigo.
loninappleton said:
Hi Lon, I believe it was the Bink CD and you have to print out the "Using the Bink AudioTest CD" document and tape it to the wall or something. Here's the site:
http://binkster.net/extras.shtml
Buenos suerte, amigo.
Re: Re: news from nowhere
Good deal, thanks rjbond3rd
There might be a tool like this inside Goldwave or Audacity but I never looked. Wait, I think Audacity does have something.
Anyway I put my setup stuff back to listening position after settling on one thing: at #4 in bink, I'm getting air action out of the port and
audible sound out of the speaker.
Then I got the thin wire wound up in the vacuum cleaner.
That sort of took care of the rest of the afternoon.
The vac is fixed though. And the wire still usable.
rjbond3rd said:
Good deal, thanks rjbond3rd
There might be a tool like this inside Goldwave or Audacity but I never looked. Wait, I think Audacity does have something.
Anyway I put my setup stuff back to listening position after settling on one thing: at #4 in bink, I'm getting air action out of the port and
audible sound out of the speaker.
Then I got the thin wire wound up in the vacuum cleaner.
That sort of took care of the rest of the afternoon.
The vac is fixed though. And the wire still usable.
Re: news from nowhere
No more so than me, the FG easily loudly overdrives the cheap CREATIVE 2.1 system I have hooked to the computer and this is with both the WAVE and CONTROL volume set at only half way.
FWIW, when I'm trying different vents I just shove them in part way and seal around them with rope caulk or similar.
WRT comparing speakers, just what are you comparing? Same-same except drivers or.....? Anyway, without good sealing there's no way to find or compare box tuning.
GM
loninappleton said:
No more so than me, the FG easily loudly overdrives the cheap CREATIVE 2.1 system I have hooked to the computer and this is with both the WAVE and CONTROL volume set at only half way.
FWIW, when I'm trying different vents I just shove them in part way and seal around them with rope caulk or similar.
WRT comparing speakers, just what are you comparing? Same-same except drivers or.....? Anyway, without good sealing there's no way to find or compare box tuning.
GM
A fresh listen test today with some organ music.
Something is not right with the 167e.
The BIB with only a $10 Pioneer in it wipes the floor with my test box.
Or spanked if you prefer.
Also vocals sound 'nasally' and cramped in what is admittedly a cramped test box. Same deal with my favorite testing material: solo classical guitar.
OTOH I do not want to make a BIB for the 167e but would prefer fine tuning it's midbass performance in the MLTL.
But for now, cramped and nasally rules the day.
GM, I looked up Fb. But I'm unsure about my tones. Then after a long download of the complete Bink cd, the zip file would not open properly and so I cannot verify things. When I made my cd, I used what I thought were the relevant tracks but never recorded the numbers properly. At that time I was just testing to see if the FE127 was 'performing' in the lower range. These more sophisticated diagnostics are a new process for me.
These Bink tracks are marked track 1 through track 30.
Not having much success with the test box I should move along to the 3 ft container discussed above. Some time very soon, I am going to lay out the measures given for the next reuse project.
This will involve using a full size router for the first time.
Something is not right with the 167e.
The BIB with only a $10 Pioneer in it wipes the floor with my test box.
Or spanked if you prefer.
Also vocals sound 'nasally' and cramped in what is admittedly a cramped test box. Same deal with my favorite testing material: solo classical guitar.
OTOH I do not want to make a BIB for the 167e but would prefer fine tuning it's midbass performance in the MLTL.
But for now, cramped and nasally rules the day.
GM, I looked up Fb. But I'm unsure about my tones. Then after a long download of the complete Bink cd, the zip file would not open properly and so I cannot verify things. When I made my cd, I used what I thought were the relevant tracks but never recorded the numbers properly. At that time I was just testing to see if the FE127 was 'performing' in the lower range. These more sophisticated diagnostics are a new process for me.
These Bink tracks are marked track 1 through track 30.
Not having much success with the test box I should move along to the 3 ft container discussed above. Some time very soon, I am going to lay out the measures given for the next reuse project.
This will involve using a full size router for the first time.
rjbond3rd said:
Well the only thing that's in there is as follows:
Fiberfill above the driver, felt behind the driver and felt along
one wall down to the base of the driver. Rest of the cabinet is emty.
There is very little space behind the driver to the back wall. I'm looking to correct that with a longer cab design.
The seal seems to be good and there's no apparent daylight around the driver gasket. I had to fiddle around getting the shallow rabbet cut right so the thing would seat properly.
I wonder if I should do some practice circle making on an open baffle and see what that does in comparison. Any larger pieces I'd have to find more likely by accident or on a post- Christmas dumpster dive.
Wait-- I have one piece of hardboard bought as a handy panel that is so bowed it's not good for anything. I got it for worktable backs.
Would a hole cut in that stuff work as an open baffle?
Hi Lon, absolutely that would constitute an OB! Definitely give it a spin and you'll at least have a way to pin down whether the box is causing the "nasal" sound.
Personally, I would line all five sides (i.e., everything but the back of the baffle) with something but I can't speak to what's "proper" or technically valid.
Personally, I would line all five sides (i.e., everything but the back of the baffle) with something but I can't speak to what's "proper" or technically valid.
Not many of the others are weighing in on this.
;-)
Oh well.
With the size of the piece I'll prob'ly use the old Rotozip and tramel (circle cutter) since the cut will be in one pass.
If I fixed the box properly according to conventions I'd worry that all the life was being sucked out of it. You are saying that the bottom should be treated in this instance as well as the sides minus the baffle back.
But I think the real problem maybe is singing in a closet. You can hear sound but it's not the right sound. If the volume of the cabinet was increased is there any calculation for increase in SPL (I think)?
Why is a smaller speaker in a larger volume able to move more air out the port than a larger unit in a smaller box?
;-)
Oh well.
With the size of the piece I'll prob'ly use the old Rotozip and tramel (circle cutter) since the cut will be in one pass.
If I fixed the box properly according to conventions I'd worry that all the life was being sucked out of it. You are saying that the bottom should be treated in this instance as well as the sides minus the baffle back.
But I think the real problem maybe is singing in a closet. You can hear sound but it's not the right sound. If the volume of the cabinet was increased is there any calculation for increase in SPL (I think)?
Why is a smaller speaker in a larger volume able to move more air out the port than a larger unit in a smaller box?
Hi Lon, if the FE127E is moving more air out of its port than the FE167E, then I would say that the FE167E's cab is not tuned optimally.
At the cab's tuning frequency, as I understand it, the port does virtually all the work and the driver's cone is "braced" (or damped) by the pressure in the box. The cone seemingly doesn't move but the port seems like it's blasting air out.
Have you ever seen the famous "candle" photo from one of the Weems books? It shows two candles -- one in front of the driver, one in front of the port. At the cab's tuning frequency, the candle in front of the driver shows virtually no cone motion, but the candle in front of the port is almost getting blown out.
GM's advice is (duh) right on -- get that little Marchand Elec. utility or the CD tones working and determine the cab's approximate tuning frequency. Then you can determine if that tuning is a good match for the FE167E. If it is, then the next step might be to consider whether the driver is properly offset from the "closed" end of the line (the end w/o the port). If it's off even by an inch or two, you might be getting a naughty harmonic coming through that an ideal positioning would have cancelled.
And that naughty harmonic could definitely wreak havoc inside the cab, and I suppose it could cause a "nasal" resonance that stuffing wouldn't tame (e.g. if it's the first harmonic). Every inch matters with a quarterwave cab, I am learning.
At the cab's tuning frequency, as I understand it, the port does virtually all the work and the driver's cone is "braced" (or damped) by the pressure in the box. The cone seemingly doesn't move but the port seems like it's blasting air out.
Have you ever seen the famous "candle" photo from one of the Weems books? It shows two candles -- one in front of the driver, one in front of the port. At the cab's tuning frequency, the candle in front of the driver shows virtually no cone motion, but the candle in front of the port is almost getting blown out.
GM's advice is (duh) right on -- get that little Marchand Elec. utility or the CD tones working and determine the cab's approximate tuning frequency. Then you can determine if that tuning is a good match for the FE167E. If it is, then the next step might be to consider whether the driver is properly offset from the "closed" end of the line (the end w/o the port). If it's off even by an inch or two, you might be getting a naughty harmonic coming through that an ideal positioning would have cancelled.
And that naughty harmonic could definitely wreak havoc inside the cab, and I suppose it could cause a "nasal" resonance that stuffing wouldn't tame (e.g. if it's the first harmonic). Every inch matters with a quarterwave cab, I am learning.
loninappleton said:
You need to get the Marchand or similar 'freebie' FG working since unless you plan to tune to one of the CD's tones it's worthless for box tuning.
Well, you didn't tell me what you're comparing, so based on the info you gave for the test box, as I previously noted it's a severely over-damped alignment due to using a much longer vent than I have a record of on your FE127E build which combined with an acoustically small cab for the low tuning means that the vent is very low Q, so won't have much output even at Fb around 41 Hz. Swap it out for a 1.5" long vent to make it a ~T/S max flat alignment and it should produce considerably more output in the upper bass, but will roll off very quickly below ~80 Hz if the cab's sealed well due to a ~60 Hz Fb.
Indeed, I thought you just cut a bigger hole in a FE127E cab, but in looking at the dims you gave me awhile back due to them being different than what I originally spec'd, it's considerably larger.
GM
rjbond3rd said:
Historically, the standard was one of each parallel walls be covered with an absorbent coefficient suitable to damp any standing waves enough to keep them from audibly reflecting back through the driver(s) and none on either the baffle or panel nearest the vent as it changes tuning by reducing its efficiency. Of course TLs, etc., require much more damping due to the strong modes generated along its length.
GM
GM said:
I appreciate all the comment and and suggestions.
I just need more practice with the Marchand program.
Regards the test box, yes it's a fresh assembly, not one of the
FE127e cabs reworked. I tried to get a little extra width by using
some quarter round all around and then making the sides with
what came to hand-- cutoff lengths of 4 in or so.
I tried to follow the Weems chart for doing a BR which meant
fitting a size in between 2 segments of the chart.
In truth, I've been working backwards from the box to the
167e. If it's not listenable, it's my own fault. I have good success with GM's measures for years so this will not be subject to a rush job.
While using the cd tones I removed the port and just listened to the
hole. There seemed some activity within the box but nothing definable.
Also I am going to a carpet store and see if they have any felt
and lay out the measures given for that next project of the
3 ftx 1 ft box (formerly BIB Jr.)
Hi Lon, call me a lazy bastard, but if it were me, I would sketch out GM's dims on paper and just follow that exactly. You are guaranteed success, unless the laws of physics suddenly change, and then hifi is the least of our worries. Otherwise, there are just too many variables. Good luck, amigo!
loninappleton said:
Huh?! In post #65 you said the vent was 5.125" long!
Right, the higher tuning combined with the shallow vent length means that relatively speaking there's much less vent 'noise', so all you're hearing is the indistinct narrow BW LF output and any mids/HF standing waves not damped to inaudibility. What matters is how far away you have to be to not hear the latter 'coloring' the driver's direct output.
GM
I doodled around a bit more today.
With the suggested length of 2" x 1.5 in long port tube plus fixing
the minimal tone control on my source to neutral, there's some improvement.
I'm still contemplating a temp. open baffle.
But as GM says I have no direct a/b comparison with 2 167e's.
As a stand alone comparison and many things being unequal, the BIB
cabinet does more with what it has than the altogether better speaker and ill-fitting temp. cab.
I have to do a bigger build where the 167e can breathe.
With the suggested length of 2" x 1.5 in long port tube plus fixing
the minimal tone control on my source to neutral, there's some improvement.
I'm still contemplating a temp. open baffle.
But as GM says I have no direct a/b comparison with 2 167e's.
As a stand alone comparison and many things being unequal, the BIB
cabinet does more with what it has than the altogether better speaker and ill-fitting temp. cab.
I have to do a bigger build where the 167e can breathe.
GM said:
I was looking over the measures you gave for another temp. job.
This should have all the right data together from a previous post:
" but if the pipe gets shortened to 36", then it's ~14.187"/39.4%. If the same net Vb is used, then CSA increases to ~132.483"^2, but it changes only a relatively small amount to ~15"/~41.64%. "
So with the pieces I have and if I did the CSA right, dims are
11.04 (rounded down to 11 in.) wide x 12 in. deep x 36 in tall all inside
measurements. And assuming 2 x 1.5 long in port out the bottom. Driver center 15 in down from top. It's a manageable size.
In the current crate, shortening the port down to the above 1.5
has given improvement.
I still have to learn to use the audio measurement tool.
Hmm, according to the sim I did back then a 3" dia. x 1.5" long vent is required to mimic the 'flavor' of the FE127E MLTL, so using a 2" will tune it down too low, ~where the 5+" long vent did in its current 'short' MLTL. Even the raw hole for the 2" dia. vent would still tune it a bit low, so I recommend a minimum of a 3" i.d. dia. vent to experiment with and even then it may be too small based on your recent tuning observations, so using 4" dia. vents of varying lengths seems to be the best choice overall, with 1.5" theoretically tuning it the same as to what the 'short' MLTL is currently tuned to with the 2" x 1.5" vent.
GM
GM
GM said:
Ok. I stand corrected. Looks like at the very least, a trip to the
Restore Store-- a local outfit that takes in cast off building materials. I donated my 3" pipe to them thinking it had come to the end of days.
No corrections on the CSA then?
We will get this thing going at some point. I can only do stuff a nibble at a time.
On a builder's note, I sort of like the look of a brown hardboard or thin MDF veneer over the usual particle board shelving elements
I have used for both economic and audio reasons over time. This for the front baffle. The reason for exploring it is because particle board will not take a fine edge and finer rebate which the 167e requires. A hardboard skin would be my preference because MDF requires very careful dust removal and respiration prep.
One sort of flaky idea I just had is to make that open baffle
which was suggested earlier and then trim the OB down as the skin of an MLTL after the test. It might satisfy multiple purposes.
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