Replacement Speakers

[Marco Giustini]

I have used "PA" speakers but I'm fussy about them and, generally, they are MORE expensive than cinema speakers as they are often built with plywood and have rigging points.

Steve, Brandon was thinking of using Home Theatre components. With that in mind I thought that some cheap PA speakers might be a better choice - of course not ideal.

If budget allows, of course cinema speakers are recommended, I mentioned that at the beginning of this thread.

[Steve Guttag]

I'll admit I did not look up the Control-25's before making that suggestion. Those are tiny, and probably don't pass as "full range"... not ported or anything. It is a small room, but maybe not that small. I guess the suggestion would be more relevant if you stumbled on some cheap or free much larger surrounds you wanted to experiment with as screen channels.

Why do you think that they are not ported? Looking at the impedance response would have shown that they are ported (if you know how to interpret the response...you can also tell if a speaker is horn loaded by looking at the impedance response). They are indeed ported (look on either side of the tweeter exit):

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Is it high fidelity? No. Is/was it sufficient for surround use? Yes. The las time I used them in a surround capacity (and note, they've been revamped into the Control 25-1 and Control 25-1L, still has a pair of ports and still doesn't have squat below 100Hz), film was still the medium of predominance. Even DTS would High-Pass the surrounds at 80Hz since surrounds were, generally, a 100Hz-8KHz channel. Now, it could certainly go beyond that range but as you get into higher frequencies, you get a lot of noise off of a 2:4 decoder (particularly of the era). Most surrounds struggle below 80Hz, even modern ones. Cinema processors and some amplifiers offered 50Hz or 80Hz HPF to protect surrounds from what they can handle.

If you haven't heard the Control-1 (any vintage)...give them a shot. They sound surprisingly VERY good. For me, the chief downside is the foam "surround" used on the woofer...that one knows will degrade and fail. I wish they used a butyl rubber as the performance is close enough and the longevity is the life of the speaker. When the Control-1 came out, it had a companion subwoofer, the SB-1. It would get the system down to about 50Hz. It was a triple-chamber style cabinet that Bose went berserk and sued Harman to discontinue (that, the Control SB-5 and the 4688).

Marco, my comment was directly to your most previous comment about using PA speakers over surrounds as screen channels. My comment, like with the Control 25 surrounds is it all depends on the room and the application. I have used "surround" speakers as screen channels that will stand toe-to-toe with any PA speaker I can think of and really stands strong against most cinema screen channels. Their weakest point is getting below 60Hz. That is why I used bass management to complete their response. At that frequency, we are well below localization.

I'm not saying that all surround speakers will do well as screen channels. Most will not. But it really depends on the speaker, and the room as to what is the most appropriate or what will work better/worse.

[Ryan Gallagher]

Thanks for the correction Steve. My rushed conclusion they were not ported was based on just sales photos, none of which had the grill removed. I’m just used to rear firing ports from the consumer world I guess and not accustomed to gleaning it from the specs.