Recent content by Maciek

Two things were probably invovled. Firstly, You don't know the transfer function of each speaker's tuning. If it was tuned for flat free field response (that is flat in most free design software) then they become boomy when placed inside a room due to boundary gain. Especially so at tuning...

S You are right in that the cone becomes unloaded and excursion goes through the roof. My point was that there is little accoustic output below the Fb which I think is handy as it reduces boomines from room modes and reduces the amount of sound escaping Your room (and spilling over to Your...

If You can hear group delay then You tune it too high. The lower we go the less sensivitive we are to distortion in frequency and phase. This is another reason to use PRs at very low tuning frequencies. In such case this null that You wrote about and in general steeper cutoff below Fb comapared...

See its like with everything in audio, solve one problem and You run into another. Of course its more sensible to tune for say 25-30 hz and avoid the extreme weight and related sag but its not unusual to do it. If I remember well this PR was sold in two flavours, one with 200 grams of factory...

No chuffing but You may get out of displacement, same issue :) but in general yes, its easier to do a PR design than a state of the art BR, like if You wanted to follow what Kef did on LS50. If You can fit a BR large enough to keep air speed down than its fine even with a straight pipe.

Its called cone sag but its the spider that gets stretched over time under the weight. So density has nothing to do with it.

Scan Speak 26W00 PR coupled with Peerless XLS12 would require 400 grams to hit 20hz in a ~20litres box if I remember well.

Yes they do but the scale of it depends of cone weight. Woofers usually have way lighter cones compared to PR which cas easly carry 300-500 grams of weight.

As stated, depends on the requirements og the design. If You want it small and go low, go for PR. Or if BR lenght is not a problem, then BR is fine. I would say BR as air doesnt sag over time and in general behaves in a more linear manner. Alas, its not suitable for every design and it has it...

PR = passive radiator. BR = bass reflex.

With PRs You can get away with very low tuning frequency, especially with limited box volume. With traditional BR that would mean a cery long port taking up a lot of space, with strong parisitic resonances of its own (other the tuning frequency).

On batrery replacement threads I saw poeple comment that some units had a loose battery issue, if You hear this noise in the earcup that connects to USB it moght be that the battery is loose, since ita glued directly to the driver.

Side firing Peerless XLS 10" with passive radiator tuned to mid 20s. With room gain it will work like a charm down to as low as You like. Mine works in a cab 22,5 cm wide, around 18-19l. I think it would still work trimmed to 21 cm.

I wonder why nobody tried to compute the dofference between ear coupler used for measurement and "personal" ears. I mean, ear's transfer function im db/f is just a different way of measuring oiter and inner ear diameter, depth, height etc. So for example if spmeone has ears significantly larger...

While EQing at source is easy as You write it becomes tiresome if You have many receivers for each source. I use my phone to play music on headphones, currently I'm using system wide EQ that was stock with firmware. But I also use it to stream Tidal via BT to a stereo in my sons room and Wiim...