This is getting out of hand

[djnagle]

I have a pair of 1005B with two 288C drivers each. I just bought a pair of 1505B with the two driver throats each. I figured I would find single driver throuts for all four horns and sell the 1005B with a single driver each.......$$$$$$$ I finely found single driver thoats for all four horns...$150.00 per pair for the 1005 and $300.00 per pair for the 1505s. I just changed the password on my bank account so my wife can not see the blood that is draining from my account. Cheers.

[Altec19]

Hi Igor!

Didn't this begin innocently enough with a pair of empty cabinets???

Later . . .

[amh]

Scary isn't it. I'm replacing all my electronics as well as the loudspeakers.

My wife hasn't moved my stuff out to the garage yet, but it can't be far off!

Good luck!

[djnagle]

Hi Altec Fan, I seem to remember a very frozen 24 hour drive to nowwhere and meeting a great guy. I will never let my wife know your true identity, she'll come hunting. Cheers. I will post pics soon.

[GM]

Why stop with puny 1505s? Time to step up to 1803s.

GM

[djnagle]

Hi GM, don't get me started. Those things would cost a mint. Acctually for my listening room I thing either the 511 or 811 would sound better but I just love the look of those big old sec horns. Cheers.

[djnagle]

Hi GM, forgive my ignorance but what exactly is "Beaming"? There are times with my 1005s when the volume is up that they can shreek. Is that natrual for those or is it something that I have set up wrong? Thanks.

[GM]

In general, beaming means that a driver/horn/whatever is no longer a point source, i.e. a generator of frequencies larger than its Sd (effective piston area). With multi-cells, it's a little more complex since we have the horn as a whole and as a number of discrete smaller ones which by design 'fan' the beaming BW across an arc of 'x' coverage angles to more evenly distribute them over a much wider 'sweet spot'.

This was fine for relatively limited BW mono theater and large PA apps when they were initially designed, but with today's wide BW systems/software, and especially at an acoustically close listening position, the increasing beaming with increasing frequency creates a very phasey presentation that excessively 'smears' the imaging/soundstaging in a typical size HIFI and/or HT app.

Some folks don't seem to mind it, but I figure it's either because they like the added distortion and/or are HF hearing challenged, both of which is very common (I fall into the latter category), so not meant as a 'cheap shot' to any who like to use them without a super tweeter.

WRT their 'shrieking', this implies to me that they sound like ripping sheetmetal, and nothing springs to mind what could cause this other than 'ringing' due to insufficient damping since they are just a collection of thin sheetmetal horns all soldered together individually, then soldered together to form one large one.

Early horns are tar filled (excellent damping), then later they were Aquaplas coated (so-so), then just painted (ring like a 10 penny nail struck with a ball-peen hammer), so if you have the latter, either limit its BW, or do some serious damping. If you choose the former, then for a 'close enough' XO point, the large multi-cells really need to be XO'd no higher than 1000-1200Hz, so a well damped 811/Tangerine CD positioned between the multi-cell and bass bin would be my recommendation. The multi-cell may still need some (more) damping, but at least you can get by with something out of a spray can.

With digital delay and some frequency response shaping, this would be awesome.

If they are already well damped, then nothing comes to mind other than something being 'off' in the signal path that's distorting the signal with increasing gain, such as a dirty/defective volume or XO attenuator pot, etc..

Anyway, please let us know what you do to correct the problem.

GM

[djnagle]

GM, maybe I used the wrong word to discribe it. It is more of a sense that my ear drums are being scratched if that makes sense. It only happens on certain CDs which sound fine on my computer system. Other than that, they are super clean and have a presents that blows me away. The imaging and soundstaging are great, it feels like I am in the band as opposed to sitting in front of them. I have a pair of Beyma CP25 tweeters I am going to play with and see if that changes anything. I am running all this thru a Rane AC23 going into a Crown 150 for the woofs and a 300B 9 wpc for the horns. CHeers.

[GM]

Without hearing them, I'm not sure what's 'bugging' you. My SWAG is either very harsh sounding diaphrams or possibly a lightly dragging VC due to dirt in the gap or slight misalignment.

WRT great imaging that puts you 'in the band' rather than in the audience where it's supposed to, this is due to all the comb filtering going on (the phasiness I referred to) within each horn and it's interaction with the other channel. Remember, good stereo is nothing more than mass quantities of comb filtering, so you don't want it within each channel also.

If you like it, fine, but good imaging/soundstaging it ain't, otherwise the B*** 901 series would be high on every audiophile's short list. Done right, you should feel like you're front row center regardless of where you're sitting in the room, or at least in a fairly large 'sweet spot', so that a number of folks can enjoy ~the same sonic experience with you.

GM