Pro vs hifi drivers - pros and cons?

[ChrisA]

Originally Posted by Andre Visser

I have stated several times that I'm talking about recordings of acoustical instruments, if you listen to amplified and other electronic instruments, then by all means use any system and speakers you like because there are no reference to what the system should sound like anyway.

I've been wanting to build a "Solo Piano Speaker". That would be a stereo speaker system that is specialized for playing recorded performances of acoustic piano. My vision of this would be two bi-ampped drivers per side.

The thing about a real piano in the room is that the sound comes from the a large 6 or 7 foot wide space, not a point. So my "piano speakers" would be placed no more than 6 feet apart in the center of the room ad be omni-directional. Then just like a real piano a listen could walk in a circle around it. I think this is the only way you'd ever hear a recording that sounds "real".

Here is another un-related idea.... Frank Sinatra invented a kind of vocal sound that could not be heard prior to recording. It is common now. He sang at very low volume into a mic that was very close. Before singers were told to "project" their voice so they could be heard in a large venue. Recording changed that. So even voice is really like an electric guitar in that what you hear is the sum of the voice, mic, effects (reverb, EQ,..) and the amp and speaker. Even a nylon string classical guitar is mic'd if it is on CD. And it's typically mic'd in a way that is not the same as you'd hear it. The engineer will place one mic near the sound hole and typically another a foot or two back and mix them

Even jazz recording from the 50's done with analog tape. The recording engineer used multiple mics and mixed them, thereby creating a sound you could not have heard if you were in the room

[hasselbaink]

Originally Posted by 45

It's not just the driver to sound. It's the full loudspeaker with its characteristic modes of vibrations. This has a negative effect just as the room.
The first generation sound (that is what comes out of the front side of the drivers only) can be obtained by room passive conditioning: passive absorption. The back-wave from the drivers must be absorbed but only selectively in order to avoid anechoic conditions.
Major problems are at low frequencies.
The lower the frequency the larger absorption volume. The absorption volume increases because the absorption coefficient of the good phono-materials falls quite rapidly with frequency. However you can't fill the full room because it doesn't sound good and precise positioning (according to room modes of vibration) becomes extremely important.
A small speaker tends to behave like point source and this is very important because it makes easier the conditioning of the room.
A large baffle = large radiant surface. You have little chance to control the interaction of the first generation sound wit that surface and then the interaction of that large radiant surface with your room. I am not saying it is impossible but it's making things even more complicated where it is not necessary, IMHO.

Cheers,
45

Imagine two 15" drivers on a 16" baffle. How much baffle area is left?
Think cone area vs. baffle area.

[45]

Originally Posted by hasselbaink

Imagine two 15" drivers on a 16" baffle. How much baffle area is left?
Think cone area vs. baffle area.

And the other sides? The medium-low frequency response will be inevitably more influenced by the room in comparison to smaller enclosures. This is the point where I make my choice: the smallest overall surface (i.e. volume enclosure) that gives me the best compromise between minimal interaction with the room and good response.

[doug20]

Originally Posted by J.R.Freeman

Hi there Doug,

My previous statements were deliberate assumptions - hypotheses intended to promote debate. I have no doubt that there are some accurate 'prosound' drivers out there, just in general, I wonder how they compare to high-end hi-fi drivers in that respect.

JF

Thanks for the reply.

I have always wanted to see the measurements comparing the two since subjectivity is a waste of time to debate.

[doug20]

Originally Posted by CLS

Quite the opposite I found.

Pro- (high efficiency) speakers is not only good at playing loud. Consistency of tonal quality and dynamics in the medium to low SPL is also their strong point. This is one of the main reasons I love them.

Maybe 98% of the time, the playing volume of my system is about equal to or even quieter than normal indoor conversation. The sensitivity of the system above 200Hz is more than 105dB/w. In such low demand, I still appreciate and prefer the high efficiency.

BTW, a lovely bonus, I'm fully satisfied with 0.7w amp on it (the mid-high section), even when watching movies or concert DVDs with bothering SPL.

Great post, you point out another very important fact. Amp headroom!! With pro style drivers there is not need for extreme watts since we are dealing with .4 Watts average listening levels vs 1 Watt. The 1 Watt listening level will clip on peaks if it isnt a 100Watt amp since peaks are 20 to 30 dBs increases for split seconds.

I did the hifi stuff for years and thanks to researchers like Geddes I have found my way to something better. DIY can not be more exciting right now.....Yeah, I should send Geddes Royalties PM me

[CLS]

Thanks for the response.

BTW, although the little amp is (maybe) rated 0.7w, the pre amp can drive it slightly into class A2 and squeeze some more power Anyway, I've never heard a single clip, even on explosions in movies or cymbal hammerings in concerts. As said, I'm fully satisfied with them in this regard.

[Pano]

Originally Posted by ChrisA

Frank Sinatra invented a kind of vocal sound that could not be heard prior to recording. ... He sang at very low volume into a mic that was very close.

I thought that Bing Crosby was the pioneer of that technique. No?

[hasselbaink]

Originally Posted by 45

And the other sides? The medium-low frequency response will be inevitably more influenced by the room in comparison to smaller enclosures. This is the point where I make my choice: the smallest overall surface (i.e. volume enclosure) that gives me the best compromise between minimal interaction with the room and good response.

A cultist of the openly baffled would say "What other sides"...

[45]

Originally Posted by hasselbaink

A cultist of the openly baffled would say "What other sides"...

Hahahaha.....

[kevinkr]

Originally Posted by 45

And the other sides? The medium-low frequency response will be inevitably more influenced by the room in comparison to smaller enclosures. This is the point where I make my choice: the smallest overall surface (i.e. volume enclosure) that gives me the best compromise between minimal interaction with the room and good response.

I'm just not sure that is the entire story, carried to an extreme in my experience this just results in what sounds like a pair of (perhaps good) speakers playing into a room and being overwhelmed by it as opposed to some much larger speakers that just seem able to disappear - generating a much more convincing sounding performance.

I admit I may have missed your point, but I guess I am just a BIB type of guy with those 11 cu ft Onken enclosures with 16" woofers in my modest sized listening room. (JBL horn mids and tweeters - 300B SE power) Sonically they almost disappear on some material and it is scary - like nothing I have ever heard from a more modestly (sanely) sized system.