Pensil 7 (Alpair 7)

[murio]

Hi guys, Mark! Can anyone tell me is it ok to fill pensil 7 with sheep's wool instead of polyfill. Because i ve heard that sheeps wool is the best for damping speakers and i can easy get some!

[chrisb]

Originally Posted by murio

Hi guys, Mark! Can anyone tell me is it ok to fill pensil 7 with sheep's wool instead of polyfill. Because i ve heard that sheeps wool is the best for damping speakers and i can easy get some!

once fully cleaned and carded to uniform density (not as easy as it sounds), raw wool is fine, but you'll probably need to adjust fill levels by ear

[planet10]

Originally Posted by chrisb

once fully cleaned and carded to uniform density (not as easy as it sounds), raw wool is fine, but you'll probably need to adjust fill levels by ear

And worry about moths & it sagging. When i used it, i mixed it about 1/2 with poly fluff so that it had greater staying power.

dave

[murio]

Thanks guys!

[gerben00]

Hi all, this has been asked before i guess but i can't seem to find an answer.. I would like the pensil's to be be a bit shorter, say around 75 cm's. Is that possible if i keep the driver's distance to the top, and the width and depth dimensions the same? Or would that totally change the design idea?

[planet10]

The length of the line (ie height) is critical. If you want a smaller cabinet, you'll need to look elsewhere.

dave

[chrisb]

Originally Posted by planet10

The length of the line (ie height) is critical. If you want a smaller cabinet, you'll need to look elsewhere.

dave

There are more than a few excellent candidates, for example the monopole MT @ page 6 of
http://homepage.mac.com/tlinespeaker...aps-150909.pdf


might be worth considering - as an ML-TL, the overall height or driver location shouldn't be fiddled with, but at 784mm might be a lot closer to your target?

If not, then there are also so excellent stand mounted "mini" monitors

[gerben00]

Thanks Chris! Still a bit more height than i would like so will look further into the stand mount options. Decisions..

[golfnut]

Hi All (first post)

I needed smallish speakers with high WAF - Pensil 7 seemed good candidate - photo of speakers attached. The speaker to the side is a KEF CS 7 - 3-way constructor series uses B139, B110, T33.

I have set the front baffle ~ 7 mm proud of the sides, for a number of reasons - firstly it provides a space to recess the bulk of a frame for a grill, secondly, I thought the leaving the front proud + rounding the edges of the baffle + rounding the sides would smear out diffraction effects, finally , I dont like the aesthetics of the original. The baffle has ~ 3 mm radius, the sides a 9 mm radius.

The american oak is probably not ideal as a cabinet material - rang like a bell before I lined it with ceramic wall tiles and screwed the back on. I have about 0.75 kg of fibre in each - a bit more than design to compensate the loss in volume with cleats on all joins and the tiles. Can just feel the vibrations in the cabinet when they are running. I was surprised, but perhaps spoiled by the KEFs. The midrange and tweeter in the KEFs is in a separate box within the main cabinet - a technique to keep in mind?

When I first turned them on I was a little surprised - they were not as clear as I expected. However they improved rapidly over a few hours. I had run them in while they were in their cardboard box for 120 -150 hours using the tuner and had got them up to a level that I would listen to the radio - quieter perhaps than I would listen to music. So perhaps they just need a bit of a stretch at higher volumes.

I am amazed at the range of this little drive unit.

The speakers have breathed life into quite a number of my CDs. I'm not sure if they're as good as I remember the Quad ESLs - I used to have a pair BW (before wife) - perhaps there is just a touch of unwanted sibalance at highest frequencies - but way better than the KEFs in the tops. There are a couple of CDs that I've always had question marks about - very heavily orchestrated and I always wondered if the recording was bad or the KEFs had a bit too much distortion. With these speakers the mud has gone.

There are a couple of CDs that are very dissapointing with the pensils - bad recordings I expect.

On the downside, as amazing as they are, there is hole in the bass end - no house shaking - nothing you can feel. Also on some male voices the timber has changed noticably. On a couple of CDs (Jacques Lousier especially), alot of the music (double bass and drums ) has all but dissappeared, although there is a lot of cone movement - they're definitely displacement rather than rms watts limited.

Whats really interesting that with the tuner on (band limited in bass and treble), the KEFs and the Pensils sound very very similar.

Overall, they are fantastic little neighbour friendly speakers (no bass transmitted through walls). Actually, theyr'e not that little - I had expected something a little smaller.

I would be really curious about running the alpair 7s as AS ( 6 liter) or BR ( 11 liter) in conjunction with a 6" or 8" BR or T-line woofer cutting in below 150-200 Hz, with the alpair in its own box within the main cabinet, as with the KEFs, to prevent the secondary radiation.

best wishes

[chrisb]

golfnut - those are cute

You didn't mention if this is your first single driver/FR speaker, but it will certainly be a major change in direction from a 30/40(?) yo KEF kit.

The A7 is certainly quite revealing of recording and equipment qualities .

Depending on room size / application and playing levels, you could possibly get away with crossing over to woofer(s) even lower than 150-200HZ - an example I often cite is a "typical" small room HT system with bass management. In my case the Denon receiver includes Audyssey system with calibrated microphone which makes setting levels of the 5.1 channels a breeze, and recommends XO points depending on the "size" of speaker set earlier. With Alpair7 in the front row and A6metals in rear, I found that 110 and 120 respectively was sufficient. There are dual corner mounted woofer enclosures.

OTOH, if you're talking about a new enclosure for a 2 channel system with the 7s and woofer - which has been described as FAST, and are needing higher SPL from a single pair than would be the case in a 5 or 7.1 or 9.2,. or whatever's next, then an even higher XO (circa 300-350) might be more appropriate. The big issue of course at such an XO is selection of bass drivers that blend seamlessly with the widebands.