Have idea, but need advice on building.

 

New member
Username: Alien_53

San Diego , California United State...

Post Number: 1
Registered: Jun-14
My idea for a speaker set up is perhaps a little strange but I can see it working, with the right direction.
I currently have no amp nor do I possess the speakers. I have built the speaker boxes with regards to a general driver config. I desire to place a tweeter and a mid in 4 cabinets that are placed in a rectangular open beam config on my ceiling, the speaker boxes comprising the 4 corners, and will be permanently installed on the ceiling. Cabinet dims are isd 6" by 6" by 15". Would like to go with max 4" mid. The other goal here is to suspend an 8" woofer from the center of this rectangle, facing up (no cab for that yet.) I have been doing an exhaustive amount of research on crossovers and actual speakers. My questions are whether I can create external crossovers for the speakers with the crossovers located in a different room (within 15 ft of the install). Do I need a 4 different 2 ways and a low pass for the woofer? or perhaps a 3 way that is capable of handling the 4 tweets and 4 mids plus the woofer. If such a creature even exists. Also a recommendation on an amp would be appreciated. I want to have all of the speakers operating at he same time. My thoughts are to have the crossovers remotely located with the hi input going to the xovers and then individual wiring to all 9 speakers. If such a config is possible how are the hi outs split into the xovers since they are not located at the speaker cab themselves. Is there any additional gear required to so that the amp sees the proper impedance load?
Am I just crazy or is this possibly do-able?
I'm not rolling in cash, but I have a some $ to spend on this. BTW the cabs are solid oak, and I believe that I have enough cu in for the small speaks to work. Covered everything ???
Thanks
ASH
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17910
Registered: May-04
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" I want to have all of the speakers operating at he same time. My thoughts are to have the crossovers remotely located with the hi input going to the xovers and then individual wiring to all 9 speakers."



I really don't understand what "the hi input" refers to. But, then, I really don't understand what you're trying to accomplish either. Four speakers (two drivers each), one in each corner of a room, connected I assume to a two channel amp. What's the reasoning behind this?

If I assume you are going to use a stereo amplifier, then you can run the outputs of the amp to one Xover for each channel if you like. Obviously, this gets you into issues with total impedance load of all the drivers plus the Xover components on each channel. I would say it would be easier on you and the amplifier to simply make connections to four discrete Xovers and make your calculations from there. Either way, as I understand your explanation, you're going to have a lot of cabling to deal with. Power loss over the length of the cables is possible and needs to be a consideration.

You say you want to use mids and tweeters but most low frequency drivers won't mate well when the drivers are separated by a large distance. A Xover allows a certain frequency bandwidth which is shared by both drivers on either side of the filter. Therefore, the low frequency driver will be reproducing the same signals for at least a portion of their output as the mids. The physical distance between the two drivers will create an obvious sense of two drivers carrying the same information. That's a situation which is normally avoided. Add in the wildly irregular frequency response created by the comb filtering of the room and you'll have sound, but not likely very good sound.

The corner placement against the ceiling is about the worst place for any driver. It's bad enough when the drivers are mounted in the celing. Put them in a cabinet so they stand proud from the ceiling and things get rather worse. There will be reflections which will cause dips and peaks in the driver's response. No tweeter will have such broad dispersion that no matter where you sit you will be hearing the full frequency output of that driver. Dead center placement of the low frequency driver is the absolute worst placement for a low frequency driver as it will excite virtually every room irregularity.

There shouldn't be any assumption of anything resembling decent frequency response with this set up. As stated, you will have sound, just not very good sound.

It's been years since I have seen anyone build cabinets without considering what drivers will go into those cabinets. The smallish mid you're proposing will have very limited bass response which will make the placement of the woofer all the more obvious as a distinct location for sound.

There are more problems than I care to deal with in this approach. Overall, I'd say this is one of the worst set ups I've encountered. But, if this is what you want and you don't care about quality, you'll have sound. The rules of physics which create good sound are all but ignored and the price you'll pay for this system would not IMO equal the sound quality you would have with a more conventional system.


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New member
Username: Alien_53

San Diego , California United State...

Post Number: 2
Registered: Jun-14
I thought it may be a bit out there but I was trying to emulate a computer type set up as far as the speaker set is concerned, just in different cabinets.Passive vs. powered on the sub. I have included a pic of the beam set up showing the proposed speaker placement, as I have not cut the holes for the speakers and wont if this seems like a lame idea. The hi in I was referring to was the output from the amp.
I was merely trying to present something different as far as speaker placement.Not being as experienced as I would like I thought I'd run it up the flag pole. I'm not a connoisseur of real fine music but I do enjoy good sounding music. Upload
 

Platinum Member
Username: Jan_b_vigne

Dallas, TX

Post Number: 17911
Registered: May-04
.


"
I was merely trying to present something different as far as speaker placement"



OK, but if I said I was going to build a car powered by oatmeal just as something different, that wouldn't make it a good idea. At times you have to consider conventions are followed due to the better quality results they achieve. You are ignoring more than a few rules which determine good sound in an enclosed space or, in more "scientific" language a resonant enclosure. Possibly you are only familiar with car audio which has rules no home audio user would apply. Home audio at its best provides the impression of performers performing on a stage, not just in an amorphous space dominated by bass thumps.

There are no audio police and it's your system to do with as you please. However, consider the conventional speaker set up - whatever that might be to you - strives to recreate a live performance on a stage in front of the listener. Your proposed set up would not recreate much of anything beyond a cave or the back seat of a Ford Focus. Even in the best set ups room reflections and what are called "nodes" (peaks and dips in frequency response) do a fair bit to work against a realistic impression of a live performance. More or less every rule we would take into account in our home to avoid poor performance from the speakers has been ignored in your proposal.

Other than repeating a desire to be "unconventional", can you state a specific goal for your set up? If not, then you might want to wait until you can do so before you invest your time and money in this project.

Just to be clear, I don't care how you place the speakers. I'm not going to show up at your house to complain. But what you are proposing does not take into consideration the rules of physics which dominate speaker design and set up. When you ignore rules, you tend to get lousy results.



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