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Posted By: akd200 KISS - 11/21/09 07:51 AM
Keep it simple they say, but they also say form follows function. Here is my dilemma, I live in Alaska and first bought a set of large vintage PA speakers, then I found another pair and stacked them on the first set. I have recently been hearing that this is a bad idea, that the using of multiple speakers degrades the sound quality. One of my friends who said this does not even care if his speaker cables are the same length! I found your site because I looked up comb filtering trying to figure out what the objection is. Any insight would be appreciated!
Posted By: Zarak Re: KISS - 11/21/09 12:15 PM
And here I thought this thread was going to be about the band.
Posted By: EFalardeau Re: KISS - 11/21/09 12:31 PM
Welcome to the forum!

Is there any particular reason you wanted them stacked? Unless they are powered by two completely independent amplifiers, you will not gain anything.

As for cable lengths, unless one if 5 feet and the other 100 feet, the speed of electricity would make the difference inexistant (not just 'inaudible', but well below the physical resolution of our ears).

If I did not answer your question, just wait and someone else will come and chip in.
Posted By: SirQuack Re: KISS - 11/21/09 01:06 PM
Welcome,

I would recommend Beth, Detroit Rock City, and Strutter.

From Ethan Winer's website
Posted By: BlueJays1 Re: KISS - 11/21/09 04:34 PM
Welcome akd200,

You have a very informed friend there. Yes, he is correct about not caring that his speaker wires not being the exact same length. These claims that speaker wire need to be identical lengths are often spewed by self proclaimed "golden ears" which lack even the simplest understanding of physics.

There are NO reasons why cable lengths between pair channels (ie. Main Left, Main Right, Rear Left, Rear Right, etc) need to be kept identical, but avoiding a ratio greater than 4:1 of identical wire gauge is good measure for minimizing RLC losses which can affect system damping factor and attribute to frequency response variations. If cable runs need to be much longer, selecting a cable of lower gauge is advised provided that the geometry and conductor spacing is conducive of keeping Inductance (recommended < .200uH/ft) and Capacitance (recommended < 50pF/ft) in check. (DellaSala, 2007)

http://www.audioholics.com/education/cables/speaker-cable-length-differences-do-they-matter




Posted By: duckman Re: KISS - 11/21/09 05:38 PM
I once read a quote from axiom's Alan that running 2 identical pairs of speakers side by side had specific advantages over a single pair. No mention of stacking,however.Sounds like something I would have done back in the day.
Posted By: jakewash Re: KISS - 11/21/09 07:19 PM
You could try toeing one set of speakers in and the other out, both slightly to possibly alleviate some of the afects of the comb filtering. The biggest thing with comb filtering is that is more of a measured concern than an audible one, at least according to Alan(resident expert) and my experience with the VP150 which is said to be very bad for comb filtering yet sounds good to me.

The biggest thing is do the stacked speakers sound any better than they do when they are run as singles or side by side, if they do then you have an issue, if they sound better or just as good than there is no reason for concern. It is all about you and how pleased you are with the sound, nothing else really matters.
Posted By: alan Re: KISS - 11/21/09 07:49 PM
Hi Duckman,

Yes, I mentioned that running an identical pair of speakers outboard of your main pair--in other words, an additional left speaker positioned farther to the left, and an additional right farther to the right of your main right speaker--greatly widens the soundstage and seems to make it more seamless. Call them "outriders" if you will.

We (Floyd Toole, myself, several others on the NRC listening panel) did this in a comparison of very early "bucket-brigade" surround processors, and we discovered that simply adding an extra pair of outboard speakers at the front provided as much realism as the special surround processors with additional surround speakers.

It's interesting that this principle has been applied by Yamaha in their "presence" speakers and also Dolby in the "height" speakers, which really just add more ambience.

I never explored stacking speakers. I wouldn't worry about comb filtering effects. It's a measurement artifact and the tests we did at Axiom suggest that the ear/brain actually likes to hear comb filtering effects.

Alan
Posted By: CV Re: KISS - 11/21/09 07:54 PM
So I'm supposed to get another pair of M80s? \:\)
Posted By: jakewash Re: KISS - 11/21/09 07:55 PM
Yes, we all should \:\)
Posted By: CV Re: KISS - 11/21/09 07:58 PM
I wish I had a room wide enough to accommodate the extras... and another A1400-8 to provide power to all of these extra speakers.
Posted By: onn Re: KISS - 11/21/09 08:57 PM
CV, you'll also need to get another pair of EP800's to even everything out \:\)
Posted By: CV Re: KISS - 11/21/09 10:35 PM
Ha ha, I wish. That would be a fun room.
Posted By: HAY Re: KISS - 11/23/09 01:49 AM
The first thread that was hijacked on the first post.....to put it on topic:

Posted By: Murph Re: KISS - 11/23/09 01:28 PM
Nice. Another item to add to my Christmas Wish List.
Posted By: Argon Re: KISS - 11/23/09 05:19 PM
To quote PeeWee....."Hmmm.....Potato-y"
Posted By: Murph Re: KISS - 11/23/09 06:10 PM
Isn't there rules on this forum against advertising, for sale items and quoting PeeWee Herman. This place has gone to hell.
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