Good article on what Jeff meant to the community and how his passing was felt all around the world: https://www.washingtonpost.com/nati...g-kidney-failure-he-couldnt-beat-coronavirus/
Very very sad that Jeff Bagby passed away
I had the pleasure of talking with him on speaker design and he was indeed the kindest and most enthousiastic man.
I hope one of his own designs will make it to the testbench here one day.
He was for instance very happy with one of his latest designs the Helios: https://www.facebook.com/groups/462464294109413/post_tags/?post_tag_id=784134678609038
I'm sure that one would test very well here for a 2-way.
Can’t wait for the Mandolin! Mandolin 2 MTM have been on my wishlist!Will add Helios to the future list, but it is more than a bit over budget. At $850 for one, unless the membership really wants to fund, will have to settle for the Mandolin I have on order for now.
I'm not saying it's definitely a problem, or a problem for all amps, or a problem for all content. But it could be a problem for some amps playing some content at high volume levels.
If it is a problem, you would need a new amp if you plan to use it with any common 2-way vented bookshelf.
Most of them have a very comparable phase dip in the bass just as this speaker does. Fortunately, it usually happens at in narrow range of high impedance and is not much of a concern.
I've seen dozens of speakers that hit -40 to -50 degrees but few that approach -70 degrees. Some B&W models might.
As Amir states in his review post, "Impedance is around 5.5 ohm which is higher (better) than typical small speaker". I have measured fewer speaker than Amir, but I concur. Plus or minus 45 degrees is considered worst case, so your statement means that dozens of speakers are just as bad (or worse) than this one.
Do those other speakers (with lower impedance magnitude) also have the low sensitivity of this speaker?
When assessing the difficulty of a loudspeaker load, the sensitivity, the impedance magnitude, and the impedance phase all play a role.
If "plus or minus 45 degrees is considered worst case," but this one goes to nearly minus 70, then I'm not sure how you deduce that "dozens of speakers are just as bad (or worse) than this one."
I post a couple of them earlier: https://www.audiosciencereview.com/...rity-diy-speaker-kit-review.15695/post-501087@amirm Forgive me if already provided, but what are these "speaker killer" bass tracks?
Apologies for nit-picking, but the terminology should be sub-bass, not subsonic bass. Subsonic generally refers to the speed of sound, ie, being below the speed of sound, not the frequency of sound. (The terms subsonic has also been used to describe sounds below the threshold of hearing - but in amplitude, not frequency. However, I don't see this in any 'official' definitions, so it may be an incorrect usage.)
One could also use infrasonic bass, but that's generally reserved for frequencies below 20Hz.
I have a third one but is not in that playlist.
I've been wanting to try my hand at some curved pieces. Anyone have any idea how they made the front left and right piece? Is it gentle enough that one can form some plywood with soaking and time or is it just easier to kerf it? Or maybe just some other technique I am not aware of?
Agree that the loading is dependent on the impedance and phase angle. Sensitivity does play a role, but so then does room size and listening levels.
Sensitivity is often not all that high with small woofers in any case. Music is dynamic and singling out one dip in the overall load is nitpicking IMO. Notably, since the segment has comparable characteristics (small. vented designs with low impedance woofers and negative phase swings in the bass region), they are likely to present comparable loads to amplifiers. Context is important here, so not sure what your samples are, but I looked at my own data and the ASR measurements for small, vented speakers.
Btw, worst case amp load being +/- 45 degrees is not from me, but from Rod Elliott (and others). See here: https://sound-au.com/patd.htm#s11
Yep, it's totally nitpicking.
Most amplifiers and preamplifiers labeled the switchable filters as a Subsonic filter. A few (NAD) called them Infrasonic filters. I don't have a problem with it, we all know what it means. Sub as a prefix means under. Under what we hear. Infra means below. Below what we hear.
I post a couple of them earlier: https://www.audiosciencereview.com/...rity-diy-speaker-kit-review.15695/post-501087
I have a third one but is not in that playlist.
THat link doesn't work for me. Even if it did, I need a track I can play in Tidal, not youtube stream if that is what it was.How about this organ piece? Someone else shared it a few days ago, and I had some fun with it. Might have to turn it up a bit, but be careful. Low note is at the very end.
Ah, I know that one! Amir's low level resolution test- AKA, The Speaker Killer.
-80dBFS 1KHz tone you have to turn right up, with a secret 19KHz 0dBFS tone to take out the tweeters without hearing anything. Then while the listener is scratching his head and wondering why his tweeters are smoking, a 15Hz 0dBFS tone to kill the woofers.