| salas |
Hello all,
How would you prefer two 3.3'' fullrange gems in a closed box not bigger than an LS3/5a arranged? Touching together as a vertical double I suppose.
But would you run them in parallel with just BS correction...or 1.5 way trading 2dB for single source above 1kHz?
Hmm any expert opinions? |
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| salas |
| There was a fairly long thread in 2003 where 7V was using 4 in a vertical tight array. Danny pointed to 1.5 way. You were about to meet and have a listen you guys. What happened? any conclusions? |
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| Timn8ter |
I've built one or two such things and prefer to mount the drivers back to back, bipole fashion, couple the magnet backs with a wooden dowel then wire the drivers in series.
Example:
http://www.timn8er.com/bipole_fostex_fe103e.htm |
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| salas |
| A friend uses them like that but reverse parallel wired for dipole and spl gain, he likes it a lot. Do you do anything more for bsc? |
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| Timn8ter |
No, having the rear facing driver in phase takes care of BSC. Wiring in phase and coupling the drivers also reduces adverse mechanical effects on the cabinet. Wiring in series provides an easier load for the amp and from what I've read helps the damping factor.
http://www.6moons.com/audioreviews/.../firstwatt.html |
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| salas |
| Thanks for your input, I will mount 2 Visaton FRS8s (8 OHM version) on a 26X16X16 cm plywood cabinet front and back and experiment bipole, dipole, series & parallel. I will listen with 20W classA triode, measure accurately with calibrated mic, and I will post back my findings in this thread when I will reach to some conclusions. |
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| salas |
Hello,
I built a pair of 26x16x16 cm boxes out of 15mm plywood and arranged 2 Visaton FRS8 parallel connected bipole (push push front and back). The driver centres are 10 cm down from top.
The sensitivity is 85 dB SPL for 2.83V @ 1m. They must sit on stands with their front baffles 60cm from back wall for best balance. I had to use a notch to cure an octave band forwardness from 1.5 to 2 kHz. I built, measured, and listened carefully to about 12 notch filter combinations. When I finalised the notch I got excellent results. The best thrill I ever got from listening to a small quality speaker (wait for 48hours for treble to open up, if the drivers are virgin). The Visatons are 15 Euro each so you can understand what I will recommend over a BBC for a small nearfield... Funny is that the result is far more exciting than a BBC too.
The Visatons go well for bass down to 80Hz arranged as such. I am posotive that the sound without notch is far inferior to the notched speaker. I am looking to experiment with TB W3-871s and I would like to know if anybody has experience from FRS8 and TB to tell me how do they compare. I am thinking of ordering a TB quad. Added sensitivity would be much better but I have seen diyers measurements of 82dB instead 87 TB says... |
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| salas |
| the cap is consited out of 2x15uF + 1x 5.6uF |
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| salas |
| Nobody ever had used Visaton FRS8 and TB W3-871s ? any comments on how they compare? |
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| joensd |
| quote: | | and I will post back my findings in this thread when I will reach to some conclusions. |
Please do so, eventually with some measurements.
Looks like a very frugal-phile(tm) and high regarded little speaker.
| quote: | | Nobody ever had used Visaton FRS8 and TB W3-871s ? |
There was a recent thread here where somebody compared both in a little TQWT.
His findings were that the Tangband sounds superior to the FRS8 but only with a notch filter. He used these values : http://lautsprechershop.de/hifi/ct209.htm
Cyburgs is also a forum member you might wanna ask him yourself: http://www.diyaudio.com/forums/show...?threadid=29321 |
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| salas |
| Greetings! It looks like the FRS8 is a european afair... I emailed cyburgs, thanks very much for the links! |
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| salas |
| I have posted closed box dimensions, measurement and the notch in page 1! |
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| joensd |
| quote: | I have posted closed box dimensions, measurement and the notch in page 1!
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Ups; red wine is obviously not good for my eyes.;)
Are 26*16*16cm outer sizes? |
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| salas |
| Yes, outside dimensions. Only a woolfelt layer inside on walls and top. I will try to take some pics soon to post. |
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| Cyburgs |
Dear Salas,
unfortunately my mail provider categorised your mail as spam, so I got it not earlier than now :smash:
Regarding Tangband W3-871S vs. Visaton FRS8: In my experience these two are exchangeable in a given enclosure, with following results:
- The Tangband needs to be notch-filtered, a good starting point is:
0,47mH
6,8uF
11Ohm
- The FRS8 normally needs no notch-filter
- When notch-filtered, the Tangband sounds better than the FRS8
- The FRS8 can handle more Volume, which is an important point when using a 3" in full-range mode.
The decision is not easy.
Nice greetings, Berndt
I made the comparison in following enclosure: |
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| Cyburgs |
I tried the FRS8 also in a bipole configuration. One of the drivers works on a TQWP tuned to 70 Hz, the other on a closed enclosure of about 4l. On the picture you see one speaker from front and one speaker from back. Note the reflex port and the cable terminal on the back.
These 170cm babies make a very distinctive impression in every room, especially as they have to be put minimum 1 meter away from every wall due to the rear facing driver :D
Nice greetings, Berndt |
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| salas |
Stunning column! bravo.
Mine works 50-60cm face to back wall and its very pleasing down to 80Hz. I urge you to use a notch on FRS8s too. Difference is night and day on mine.
True the visaton bipole takes some power but the TB looks like considerably more sensitive. Isnt it in practice? How about the HF air? which one sounds more open? |
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| salas |
Some pics here. Listened with Gaiclone also. I prefer the 20W PP class A triode valve amp.
Gainclone is amazing value but still with cold ss heart.
The lil speaker is very revealing but it does not judge hard. Tends to highlight the good traits of the various amps driving it. It took the 30W GC (with 500VA toroid) without compressing or hitting stops. The volume was good for the 30sqm space we listened in.
As for the TangBand vs Visaton comparison, I will let you know in due time bcs 4 W3-871s are on their way to me :) |
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| salas |
| ... You can see them next to the valve amp. The notch filter can be seen also. |
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| salas |
| ... beveling both the inner baffle lips is essential not to compress transients... |
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| salas |
| ...Frugal stuff that sing...Gainclone and notched FRS8 bipolars side by side ;) |
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| Timn8ter |
| It's wonderful to watch your project unfold. Thanks for sharing!:cool: |
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| Cyburgs |
... are really nice and well done!
How did you manage to insert the FRS8s flushing with the front?
I tried the notch that you suggested and made listening tests and also some measurements. You are right, your values linearise the frequency plot as you said. And although it is only 2 dB or so, the difference is clearly audible. I did some small adjustments to optimise it to my enclosures (needles).
On the other side I like them without notch also, because they sound more dynamic. I don't know which setting I prefer, I think I have to do further listening tests.
Thank you and nice greetings, Berndt |
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| salas |
Greetings,
The needles go deeper, its normal they sound fuller without notch, so the difference is smaller to employing one than in my compact speakers case. Though it can seem trivial, spot on balance vs near balance is a world apart in appreciation of musical works IMHO. So I always ditch a couple of shouty dB's in such cases.
My FRS8s arrent really flush bcs this isnt possible with their particular chassis which I suppose is made to be mounted behind a thin wall baffle like on a TV chassis or an instrument. They are just fitted the neatest possible. A major cause for some unavoidable diffraction is this, and the protruding rim around their outer suspension as well. One of the reasons I ordered the TB 871 is to avoid this diffraction and gain some deciBells. I will report as soon as I will get the TBs and build a comparison pair. |
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| salas |
Hello again
After quite a while I return with the W3-871S version.
Built a very nice pair of birch plywood boxes, exactly the same as for the Visatons. Push-Push omni again. Great looking drivers on great boxes. First note played and ...bliah! Response taken in the farfield and...see graph. I will try with notches but I hate the dBs I am gonna lose in this one. Any way I will keep you posted.
Visaton FRS8 and TB W3-871S are supposed to be cool for same projects with little tweaking to adjust. 'Supposed' seems to be trickier here. |
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| salas |
| Ok I fought the graph. Here's the notched one. But what a loss of spl... Moral is DONT use TB W3-871S for bipole. |
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| salas |
Using a notch of 15,47uf 0,35mH 4R7(The FR plot can be seen in the post above), in series with the paralleled units, impressions are of a cleaner and lusher sound than the FRS8s in mid and high. Also more HF. But the FRS8s go deeper and give a sense of a substantially fuller sound in the particular cabinet.
The TBs break gently with volume, where the FRS8s play a litle louder but break abruptly with more obvious noises.
I would like to port the cabinets for TB. The simulations show much more LF extention to be gained. I have second thoughts about power handling though, since the reflex is going to work under the units Fs.
Did anybody do it? Maybe planet 10? I would appreciate your experiences or views. |
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| joensd |
Hi,
I built a "little" ML-TL with the TB that I always wanted to try as bipole.
Quitted the project for now as it will be too big as PC-speaker.
Enclosure as described here
Measurements and a picture in post44.
Turning it into a bipole youŽd theoretically just have to double the cross-section-area and adjust the port.
IŽd definitely try it. Do you use them for your main speakers/far field?
greets |
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| salas |
| Hi, I use em as main now along others. I want to use em as small room and pc speakers ultimately since they measure only 26x16x16cm outer. I am pleased with the clarity, feeling bad about not gaining in spl much from bipole as with other units, due to the particular way they sum that has to get ditched by the notch. Bipole still gives em wonderful spacious presence. Since xmax is far better with 2 units per speaker I think I will go for bass reflex and report when ready as usual. Maybe I endup with a balanced little bipole nice for Jazz. Joe Sample sounded great already in the currently sealed bipole. |
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