And Now For Something REALLY BIG

[JRKO]

A penny for your thoughts on passive/active for CD tinitus

what of PLLXO?

[tinitus]

Originally Posted by JRKO

A penny for your thoughts ....

impedance interfere with passive xo, and changes its function and resulting response, phase etc

and compression driver/horn combo is even worse, with multiple impedance ressonance peak

active is at least free of those speaker impedance issues
still have to deal with acoustic response tho

I guess those problems might have made the CD's bad reputation of sounding very harsh much worse than it deserves
and no doubt it will sound unbareably harsh if the xo is not functioning properly

on the good side, I don't think you need any fancy amplification for a CD
probably a simple low power chip amp will do fine, and be very simple

the remaining other drivers might still work with relatively simple passive xo

[JRKO]

tnx tinitus.

So the passive crossover is passive in both directions - subject to the drivers impedance anomalies - just because it is designed to give the correct crossover freq. & slope , it may not due to the driver attached.

An active crossover is essentially line level (before amplifier) and not subject to driver feedback, stamping its exact filter upon the signal before amplification with no speaker level interaction.

This should also be true of a PLLXO?

[IG81]

Originally Posted by JRKO

tnx tinitus.

So the passive crossover is passive in both directions - subject to the drivers impedance anomalies - just because it is designed to give the correct crossover freq. & slope , it may not due to the driver attached.

An active crossover is essentially line level (before amplifier) and not subject to driver feedback, stamping its exact filter upon the signal before amplification with no speaker level interaction.

This should also be true of a PLLXO?

Yep, this is the case AFAICT. I've tried both PLLXO and active via mini-DSP and it's much better than passive speaker-level Xover, at least at my design skill level.

IG

[JRKO]

Originally Posted by IG81

at least at my design skill level.

which is no doubt many levels above mine!!

[buzzforb]

Little update on my project. Decided to get some Altec 416's. Got them used for a good price. Also got some Altec 288 compression drivers. That leaves just the horn profile. I will begin my build in a couple of weeks, so hope to have some more extensive impressions soon

[JRKO]

Altec all the way buzzforb?

The 288 is a 1.4 incher if I remember correctly. I read (http://alteclansingunofficial.nlenet...ers/TL_231.pdf) that the 288 starts really dropping of around 15k.
Response graph shows big drop. Are you going to prop it up with a s/tweeter or EQ the hell out of it?

be interested to see you construction of the iwata!

[buzzforb]

Depends. I will probably allow for super tweet or small horn in design. May not need it. Prefer as little EQ as possible, but will do what is necessary. Here is my thread if you want to drop in. Ill stop polluting yours. Hurry up and get something. Its a build off!

Be forewarned. Lots of screwing around

Horn/TL combo

[Pano]

I don't try to force my Altec 288s much past 6K. I use bullet tweeters above that. They go out to about 17K-18K.

[Cal Weldon]

I have had success with the 288 up to 10k with a super taking over from there. Wait are we still talking buzzforb's stuff here?

Someone should call a moderator for all this OT stuff.