21216's 39 ea BIN

[alancohen]

To be fair you should build fixed pad for the 288's to try to get the L-pad somewhere in the middle of it's range with the 288's.

To balance a passive system i like to start with the HF way low and bring it up slowly to more or less a point of balance. It sounds like the L-pad is hugging an extreme to get the 288's close to their balance point which is gonna make it pretty hard to make a fair assessment.

You would think that on packaged "system" like this A6, the "pad" should be built in to the crossover. It's not like I'm mixing components. This system was sold this way. Like I mentioned, the only think I can think of is that it was meant for an environment where a lot of ambient noise was expected and the HF is hot to overcome this. I'm sure it was not meant for a small room like my living room where someone would be sitting 9' away.

The 802s seem a bit mellower in the mids, well more than a bit, and more extended in the highs. To be honest, at first blush I don't feel like I'm missing anything. That surprised me. I might measure them, then again I might not. I tend to prefer measuring with my ears. I have several 'reference' songs that tell me what I need to know. And a major factor for me is whether the music pulls me in, or pushes me away, especially after a longer session. First impression is that I could listen to these all day.

Part of what I think it might be is with the 288s I can here the horn itself. I can hear the fiberglass resonate as certain points. The 802s don't seem to 'ring the bell' as much. I wish I could try them with a different horn, but this is all I have at the moment.

[bowtie427ss]

You would think that on packaged "system" like this A6, the "pad" should be built in to the crossover. It's not like I'm mixing components. This system was sold this way. Like I mentioned, the only think I can think of is that it was meant for an environment where a lot of ambient noise was expected and the HF is hot to overcome this. I'm sure it was not meant for a small room like my living room where someone would be sitting 9' away.

I think you're probably spot on.

The 802s seem a bit mellower in the mids, well more than a bit, and more extended in the highs. To be honest, at first blush I don't feel like I'm missing anything. That surprised me. I might measure them, then again I might not. I tend to prefer measuring with my ears. I have several 'reference' songs that tell me what I need to know. And a major factor for me is whether the music pulls me in, or pushes me away, especially after a longer session. First impression is that I could listen to these all day.

Part of what I think it might be is with the 288s I can here the horn itself. I can hear the fiberglass resonate as certain points. The 802s don't seem to 'ring the bell' as much. I wish I could try them with a different horn, but this is all I have at the moment.

The 288 produces far more acoustic energy. Most of the horns designed to be used on the 288 had significant damping. Seems logical that some of the fiberglass horns might benefit from the application of some type of damping as well.

I recently had to return the 288C's i had been loaned so my listening comparisons are pretty limited at this point. But, your listening impressions seem to more or less mirror mine where the drivers are concerned, and would further seem to support the upward shifted response(GM and OG been tellin us this for a while) of the small format tangerine drivers.

[alancohen]

But, your listening impressions seem to more or less mirror mine where the drivers are concerned, and would further seem to support the upward shifted response(GM and OG been tellin us this for a while) of the small format tangerine drivers.

And of course this now begs the question: should I be switching the XO from 500Hz to 800?



I tried it briefly on one speaker and the difference did not jump out at me so I put it back. I wanted to keep listening with all else equal except the drivers for a while. By the weekend I will try 1200Hz for the opposite extreme and again listen for a while. This N1285 XO is pretty handy. Not sure quite what's in the box though.

[bowtie427ss]

Not sure quite what's in the box though.

I can't remember which thread, but i asked about this not too long ago and AB posted a great pic of a naked 1285 XO. Hopefully, he'll see this and know just what to do.

[Phil-G]

Part of what I think it might be is with the 288s I can hear the horn itself. I can hear the fiberglass resonate as certain points. The 802s don't seem to 'ring the bell' as much. I wish I could try them with a different horn, but this is all I have at the moment.

i was noticing that the horn was made of fiberglass. i'm suprized it doesn't ring a lot. especialy from the LFs. it looks like they have a fair bit of undercoating on them. so getting anything to stick would be a challenge. the next thing would be an enclosure. there is a composite called coosa that is very dense. but it would need to be incorporated into the layup. if i had a plug i'd have a pair or ten made up.

[bowtie427ss]

it looks like they have a fair bit of undercoating on them.

That's just the raw side of the fiberglass painted factory gray. Should be easy to get adhesion, and you need to be careful about getting splinters.

[Phil-G]

That's just the raw side of the fiberglass painted factory gray. Should be easy to get adhesion, and you need to be careful about getting splinters.

i sure know those splinters. what do most of the guys use to deaden them with?

[Alien_Shore]

You would think that on packaged "system" like this A6, the "pad" should be built in to the crossover. It's not like I'm mixing components. This system was sold this way. Like I mentioned, the only think I can think of is that it was meant for an environment where a lot of ambient noise was expected and the HF is hot to overcome this. I'm sure it was not meant for a small room like my living room where someone would be sitting 9' away.

No doubt about it. They call them "large format" for a reason. One thing that I've read about is to simply swap out the diaphragms for the higher impedance type to help balance out a "hot horn"...If it's really overwhelming your LF, you can do both (switch to a 16 or 32 ohm fram and employ an L-Pad to attenuate the level).

[alancohen]

No doubt about it. They call them "large format" for a reason. One thing that I've read about is to simply swap out the diaphragms for the higher impedance type to help balance out a "hot horn"...If it's really overwhelming your LF, you can do both (switch to a 16 or 32 ohm fram and employ an L-Pad to attenuate the level).

Funny you should bring that up. I'm getting these new 300B monoblock amps soon. Supposedly they delivery a steady state 1.5W into 8 Ohms. I was planning on trying them with my 604s, which are 16. In my limited electronics mind, I was concerned that I would get less power because the impedence is higher. But in reality I would get 50% more power into a 16 Ohm speaker according to the designer. This makes sense since the higher the resistance, the greater the voltage drop across it.

So, by replacing the 8 Ohm phragm with a 16, would that actually help the issue, or hurt it?

[Altec Best]

I can't remember which thread, but i asked about this not too long ago and AB posted a great pic of a naked 1285 XO. Hopefully, he'll see this and know just what to do.

The 288s are amazing, but they are very hot. I have to keep the attenuation knob almost off on my A6s to tame them. It might work in an outdoor environment or a big auditorium where the extra HF might be needed to cut through the ambient noise, but that's not the case in my LR.

I should try increasing the crossover freq. too. Maybe running them at 800 or 1200 will take something off and give the 3156s a chance to catch up.

The problem is the 288's are a lot more efficient so that is why they play a lot louder than the woofers.. You can try a 30904/30923 attenuator board... I have both the 30923 and the 30904 that i just got recently. They are used for matching less efficient woofers to higher efficiency Compression drivers.


Altec 1285-8B Crossovers by Altec Best, on Flickr


Altec 1285-8B Crossovers by Altec Best, on Flickr


Altec 30923 Attenuators by Altec Best, on Flickr


HPIM3065 by Altec Best, on Flickr


HPIM3066 by Altec Best, on Flickr


Altec3090430923 by Art J., on Flickr