The material used was open cel packing foam -- working part time at an Apple dealer i get to take home spare packing boxes. Apple parts boxes come with a variety of foams, in this case i used a piece that was ~2" thick. I (actually Chris did it) just cut the foam to friction fit on the sloping back wall.
Over the weekend i hooked these up to the main rig. These may well be the best FR125s i've heard yet -- i didn't do a direct comparison to the miniOnkens. And that without having treated the cone (which made a dramatic difference in the miniOnkens & the bipolar ML-TLs). The small aperiodic box seems to bring iron fisted control to the bottom.
dave
Over the weekend i hooked these up to the main rig. These may well be the best FR125s i've heard yet -- i didn't do a direct comparison to the miniOnkens. And that without having treated the cone (which made a dramatic difference in the miniOnkens & the bipolar ML-TLs). The small aperiodic box seems to bring iron fisted control to the bottom.
dave
planet10 said:When it 1st came out, i did a speculative design for a small aperiodically loaded FR125. Here is a realization -- 4.5 liter aperiodically loaded CSS FR125S.
hi Dave,
Did you use software to come up with the Aperiodic design? If so, what did you use? I am looking for some aperiodic design tools.
Except for stretching martin's sheets there is no aperiodic box design software that i know of.
Somewhere i have EJ Jordan's paper on it...
I use 2 different technics...
1/ make a sealed box with a Q between 1.1 and 1.x and then play with the resistive porting.
2/ design a vented box with a certain shape (i know it when i see it), and then play with the resistance in the port.
You can use GM's clik test or look at the impedance curves to get some feedback that helps get it right.
dave
Somewhere i have EJ Jordan's paper on it...
I use 2 different technics...
1/ make a sealed box with a Q between 1.1 and 1.x and then play with the resistive porting.
2/ design a vented box with a certain shape (i know it when i see it), and then play with the resistance in the port.
You can use GM's clik test or look at the impedance curves to get some feedback that helps get it right.
dave
Dave,
That paper would be great if you could find it. Do you have a title for it?
I had thought about the impedance curve. What is the clik test?
That paper would be great if you could find it. Do you have a title for it?
I had thought about the impedance curve. What is the clik test?
GG said:That paper would be great if you could find it. Do you have a title for it?
http://p10hifi.net/tlinespeakers/TLS/downloads/TedJordanAperiodic.pdf
What is the clik test?
I have a description somewhere from GM, but Terry O recently posted a desctiption and i have that handy.
There's another hi-tech solution available, I first heard about it on the old Bass List years ago when Greg Monfort (GM) suggested using a 1.5 Volt battery and a momentary contact switch to use for the "Click Test". When the switch or button is momentarily pressed the cone should move foreward (polarity test) and will emit a click, bonk or bonnnngg. The fast recovery "click" sound with no overhang, echo or ringing is what you're shooting for. You can start at either end, adding stuffing to an empty box or removing stuffing from one already stuffed.
It's kinda fun to do and is very instructive, IMHO. Just keep one box unstuffed for your "control" unit. When you get to your best solution, just duplicate for the remaining speaker and you're done.
dave
Some one say aperiodic. Got to the baffles on my Wharfedales today.
Radius on the cutout, and 16 1/2" holes. (based on a 2" dia port to tune to 38Hz) This is only 1 cubic ft of enclosure.
Better bottom end than my bass helper which is now collecting dust.
The idea of venting the cabs was to relieve the back pressure on the cone. Did that all right, and a bonus, now true full range, and higher SPL.
No measurements as yet other than SPL on music. High 90s at 3.5 metres (where I sit) with no sign of stress.
Back to the music,
Geoff
Radius on the cutout, and 16 1/2" holes. (based on a 2" dia port to tune to 38Hz) This is only 1 cubic ft of enclosure.
Better bottom end than my bass helper which is now collecting dust.
The idea of venting the cabs was to relieve the back pressure on the cone. Did that all right, and a bonus, now true full range, and higher SPL.
No measurements as yet other than SPL on music. High 90s at 3.5 metres (where I sit) with no sign of stress.
Back to the music,
Geoff
Attachments
My test-bib
Hi,
Well, my first shot at the BIBs...
Just a test model: 125 high, Fostex 127e, Smouth as per Zilla's pages (The smaller one)
I'm gonna make some new ones, in MDF, with the larger Smouth.
Pity MDF comes in 122cm sheets, not 125.... But I'll find something.
I'll feneer them like I did the sub in the corner (10" el cheapo LT0ed thinggy)
Cheers, Bibster
Hi,
Well, my first shot at the BIBs...
Just a test model: 125 high, Fostex 127e, Smouth as per Zilla's pages (The smaller one)
I'm gonna make some new ones, in MDF, with the larger Smouth.
Pity MDF comes in 122cm sheets, not 125.... But I'll find something.
I'll feneer them like I did the sub in the corner (10" el cheapo LT0ed thinggy)
Cheers, Bibster
Attachments
Hi,
an friend of mine has build up an surround system with a Philips 70800MD.
pictures (big ones will come soon) can be seen on my private page: www.hornlautsprecher.de --> Galerie --> Uwe
regards Till
an friend of mine has build up an surround system with a Philips 70800MD.
pictures (big ones will come soon) can be seen on my private page: www.hornlautsprecher.de --> Galerie --> Uwe
regards Till
Here are my BLH FE166E. The text is in french but there are pics down the page...
http://www.jcayer.com/bricolages/fe166e.htm
http://www.jcayer.com/bricolages/fe166e.htm
FE167 Open Baffle
Here is my most recent speaker, a fostex FE167 in an open baffle, which I currently use as center speaker in my home cinema system. It consists of 3 pieces of 15mm plywood, each 30-by-90 cm, with the wings folded back 45 degrees. The backside has a layer of cork glued to it. I was very curious to do an open baffle and actually used the plywood I had originally intended for another project that never went beyond planning. I imagine there are speakers better suited for OB than the FE167 - this was simply the result of being bored and having stuff laying around. For cable I used a variant of 4 lengths of CAT6 braided in a symmetric pattern, directly soldered to the speaker, without using posts. This speaker sounds real good, but I have no reference as it is the first time I used the FE167, so I cannot make any more substantial claims than that I am satisfied with the results. However, due to its form-factor and limited bracing, it feels rather flimsy; I expected the top section to provide more bracing than it did, so this is something I would change if I built another one, and I would also probably make this section asymmetrical to help smooth out its response.
Here is my most recent speaker, a fostex FE167 in an open baffle, which I currently use as center speaker in my home cinema system. It consists of 3 pieces of 15mm plywood, each 30-by-90 cm, with the wings folded back 45 degrees. The backside has a layer of cork glued to it. I was very curious to do an open baffle and actually used the plywood I had originally intended for another project that never went beyond planning. I imagine there are speakers better suited for OB than the FE167 - this was simply the result of being bored and having stuff laying around. For cable I used a variant of 4 lengths of CAT6 braided in a symmetric pattern, directly soldered to the speaker, without using posts. This speaker sounds real good, but I have no reference as it is the first time I used the FE167, so I cannot make any more substantial claims than that I am satisfied with the results. However, due to its form-factor and limited bracing, it feels rather flimsy; I expected the top section to provide more bracing than it did, so this is something I would change if I built another one, and I would also probably make this section asymmetrical to help smooth out its response.
Attachments
My FR 125'S in a closed box.
Sprayed by a coating they use on pro speakers.
Compromised URL removed by Moderation
Sprayed by a coating they use on pro speakers.

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FT-1600 MKII
I finally finished my FT-1600 MKIIs. Bought the plans from Bob Brines. They sound great. I still need to get the BSC on there. Partsexpress is back ordered on the inductors. 😡 I am very please with how they turned out.
I finally finished my FT-1600 MKIIs. Bought the plans from Bob Brines. They sound great. I still need to get the BSC on there. Partsexpress is back ordered on the inductors. 😡 I am very please with how they turned out.
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