Please help my A7-500 's come alive

[Russellc]

Strange, very strange, I use both the 416 8c as well as the 515 8g(not at the same time!) in my A7s and either driver sounds wonderful ( to me). I use the 501 8 b crossover which is fixed at 500 hz. ( would like to upgrade crossover) While sound is not "perfect" it is anything but what you desribe. Have you measured the impedance of the woofers? sounds basic but maybe one has a dead voice coil, but this is unlikely if they are NOS drivers. I do use exclusivly tube amps but have heard good results w/ A7s on SS amps. I wouldn,t bother with obtaining an amp with a loudness control, that isn't going to fix your problem. As to driver moving visibly, with mine cranked there is little if any visible movement. I would throw together a 12 db crossover
and temporarely substitute it for yours. Otherwise I would suspect your 515 8gs.

beat of luck, Russellc

[LICORNE]

The audio reproduction process is far from perfect, even under the best of circumstances. Every step causes some degradation of the audio signal. What is happening involves the loss of some of the harmonics or overtones of the sound, the fragile parts that give it intelligibility. Equalizers cannot restore clarity and realism because they can only work on what's left of the original sound, often increasing noise and distortion in the attempt.
Although the initial impression of the Aural Exciter is often that it is some form of EQ, a comparison soon proves the difference. Equalizers are a static, fixed process, and they cannot boost what is no longer there. Equalizers can also add considerable power to the amplifier output, possibly causing amplifier clipping, speaker damage, ear fatigue and/or increased reverberation.
The Aural Exciter is a dynamic process that actually recreates the missing harmonic material and adds it back in the form of a very small cue signal. Because the enhancement signal is so small, it adds little power to the audio signal. It is easily reproduced, even by low quality systems, and is not affected by acoustic problems, such as "dead zones" or reverberant fields. Because the harmonics or overtones created are derived from the main signal and are musically and dynamically related, the result is very natural and pleasing to the ear, and sounds "correct

[Russellc]

Steve, just another thought. You never mentioned what sort of room they are in. If in a relatively small area, (mine were once in 12 x 17) I found they were kind of dead firing straight on, but upon tilting them in so that the axis crossed about 1/2 to 2/3 of the way to the listening position, things improved a lot. This is about the only way I could get them to image well. As for loudness controls, exiters, etc have fun, but you are putting a bandaid on some other problem. Your A7s should be slapping you around, with movie effects that will make you jump. I do not understand how any machine is going to add back what is missing, but I have no doubt that it will add something, but that something wasn't on the original recording. I must admit that I have never listened to one of these, and am a hardcore minimalist in terms signal processing. i haven't had an receiver ever, and did own an integrated w/ tone ,loudness etc in the early seveties, then went to solid state seperates in the late 70s. None of them had tone or loudness, went all tube in the 80s (again no tone controls) remained all tube ever since, unless you count a counterpoint pre amp that had an out put/buffer fet of some sort in it. While I may be predjudiced against signal processing , and the A7s are not perfect, lack of dynamics is NOT one of their short comings, something is out of whack here. I suspect the 5158gs, but being NOS this is hard to believe. After recone, my 515 8gs had to break in again, but they were already moving some air out of the box. Is someone in the area you are in able to bring a set of 5158Gs or 416 8cs to try a swap to compare?
Others models may also fit but both of those fit my 828.

Best of luck & keep all advised

[stevelubker]

Wow..seems I have a bit of work ahead.I think I will open these up and start the wiring from scratch as well as adjust the port size..When I built these they were going in a fairly big room about 20 x 24...well things happen and they now sit in a 16 x12 room (too small)the upnote however is that I don't have to listen about the size issue anymore (lol).If I remember correctly,I read somewhere that because the voice coil is behind the magnet on the horns and in front on the 515's that they should be wired out of phase??Also the crossovers have volume controls and I was never sure at what level to set them at? Is there a simple test to set a reference or do you just dial in what you feel is correct?I want to try some of the simple things first..I came home the other day and the house was shaking outside and nieghbours looking strange..seems my son and a few friends decided to play some Pantera on my babies ...no I wasn't too happy but Altec may be making friends with a new generation...thing is something must be happening with the bass...there just isn,t alot ending up in the listening area...I will try to get some pictures posted and try to work on the wiring first...busy time of year so looks like a project for the new year...thanks again for all the help and encouragment,...steve

[Fitts]

Just a quick note on the voice coils. Altec drivers are wound so that positive voltage to the the L1 terminal pushes the diaphram away from the magenet or backwards, toward the rear. Treat the L1 as though it were a negative terminal and you will be all set if you are using a crossover other than Altec which I believe compensated for the difference in its internal wirning.

Regarding the 75 square inch port, I think with your smaller room that you will notice a big difference once you shrink that port down. I have my VOTT's in a 12 by 16 room and the bass rattles anything that isn't nailed down.

I find that balancing the HF output to the LF is mostly personal prefence. My son, whose ears are good, says my system sounds too sharp for him. If I set the HF to his prefernec I feel like I have cotton in my ears. To each his own !!

Last, what crossovers are you going to use? Do you think the N85008A units are working correctly now?

Regards,