GoodSoundClub - Romy the Cat's Audio Site

In the Forum: Audio Discussions
In the Thread: Macondo’s MiniMe or about Pilot Acoustic Systems

Post Subject: How to properly high-pass a full-range driver.Posted by Romy the Cat on: 2/19/2009

Paul S wrote:
Probably not news, but: http://www.supravox.fr/anglais/haut_parleurs/135_LB.htm Another one that at least looks the part.

Thanks, Paul. This Supravox 135 LB indeed looks like an interring driver for a project of mine. I have no experience with Supravox drivers, it look like then do not swim over the Atlantic well.

Romy the Cat wrote:
Anyhow, let see how F120A will work in band-path. It is possible that it might be good enough (for MiniMe objective) without any tweeter – I will be only welcoming this news.

I was thinking about it further: if the Fostex 120A will be able to care HF acceptable enough without annoying me then I might end up to use one driver per monitor. Than begs tow biggest questions: what box to use and how to crossover the driver at the bottom. About the box. Sure I do not what it to be big. The Planetary’s David Dlugos proposed Aperiodic idea and send me information how it might be implements. Good idea but it would still require a slight bigger box then the MiniMe’s MF section is. I was looking at my closet and I have found a box the shape and dimensions I like – I will try to us it. It will be with semi-open back, let see how it goes. The approximate estimate of crossover would be 300-500Hz. I think I will measure how it will response wide open and then will cross is an octave or two above to let it to be stressed with less pain. Now the question how to cut the LF off the driver. If I have 200Hz then I have 100uF cap sitting in series with the driver. Molts likely I will go for my favorite active biasing filtering but I doubt that I like to pass the HF over this thing. I will not be able to use RL filer as it will eat a lot of gain. So, what other options I have to suck LF out of the 120A driver? A bi-amping with line level RL filter? That is a chance but is anything more elegant in there?

The Cat

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