Lines of 5.25" full rangers?

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What can expect, performance wise?

This is in my basement. The purpose is mainly music while I work out, maybe sporadic light DVD and video game use.

I've got the old TV sitting on the old entertainment center in a corner of a raw concrete basement. The center is tall and skinny, and the edges of it are towers that were meant to shelve media, but I've got it reversed so what it actually makes is a pair of tall skinny U baffles.

Up till recently, I've had a pair of old Pio 4" 2-way car audio drivers in ther, running from the sub amp unit of an old set of Logitech Z3s. All I can say about that is that it worked. Never could get the bass integrated well, but then it was just a quick and dirty setup for quick and dirty use.

If the towers had been wide enough, I would have mounted a pair of 6"x9" that I have in there and be done with it, but sadly they don't quite fit, so I've been thinking about using some Durabrand (walmart brand) 5.25" bicone car audio drivers ($9 each and locally available). They, of course don't have any parameters for me to work with. Being car drivers, I'm assuming they have middling to high Qts and comparing them to other brands of cheap car drivers at AutoZone et. al. I'm guessing I'll really only get ~100-15,000 out of them.

Probably not going to be satisfying with a single pair, so I was thinking of working up to short lines of 4 drivers, maybe possibly working up to 8 drivers per side long term. I thing I'll need to damp the back wave on the U baffles a bit to cut down on the raw concrete ring. I know I should be getting some sort of combing artifact, but I've never heard this for myself before.

What I'm wondering is, for such a cheap, quick and dirty setup do you think it will be serviceable? I have a crappy old receiver I can power them with, so I can try to EQ some bass and treble back into them (though obviously the bass will be the primary goal). Will 4 or even 8 drivers per side get me any extra extension on the bottom end, or will it simply jack up my sensitivity. Will the combing at about 5.5'-6" between acoustic centers really sound that bad, especially given that I'll likely be moving around pretty much continuously when using this system? Would I be better served moving down to the 4" or even 3.5" drivers they offer ($7 and $5 apiece, I think) I'd defintely have to drive smaller drivers from the Logitech sub so I can still have some bass, though I might build a larger U baffle out of a super heavy cardboard box and a pair of 6"x9" drivers I have on hand, probably pulling the Logitech amp to drive the whole rig (or maybe use the receiver and the Logitech amp in concert, using the receiver's crossover).

Anyway, sorry for the ramble there, but I'm just looking for some more experienced commentary before I slowly start accumulating drivers for this project.

Thanks,
Kensai
 
A word of caution

Kensai said:

Up till recently, I've had a pair of old Pio 4" 2-way car audio drivers in ther, running from the sub amp unit of an old set of Logitech Z3s. All I can say about that is that it worked. Never could get the bass integrated well, but then it was just a quick and dirty setup for quick and dirty use.



First off, I have no idea how you're getting anything but bass from a sub-amp.

Second, I wouldn't sink too much money into those Durabrands until you've heard just a pair. I haven't heard these, but I'm ambivalent about their mylar whizzer and dome producing much in the way of usable treble. I've seen that Wal-mart sells surface mount tweeters though.

Don't be afraid to search around the web. Their are still some auto sources for dual cone FRs that are going to be better than the Durabrand. E-bay is prolly the easiest way to search for that type of driver anymore.

Unless you have an ohm meter, I wouldn't trust what impedance the Durabrand were, since they don't even list that spec either. You could end up frying something with too low of an impedance.

As far as power goes, you don't have to use toobs to enjoy fullrange or single driver sound. But clean power is everything. I have used crappy recievers in the past. And crappy power will make you chase your tail!

I would stick with something simple at first. I don't know what kind of receiver you have, but something tells me it would be better (or no worse than) the Logitech whatever.

Try using what you have (Pioneer?) hooked up to your reciever (make and model?) and give that a listen. Then by all means, check back in here. I was exactly where you are right now, and to be honest, ain't much more advanced.
 
The 6"x9"ers I have are Kenwoods. I've got a pair of them upstairs in the office running off a T-Amp in small OBs . . . they're great. If I could fit them into my existing structure, I would, but the space is maybe 6" wide on the outside, by 5' tall, of course, which is why I'm thinking of playing with some cheap drivers and making my first set of line arrays.

The Logitech amp is a multimedia (PC) 3 channel amp, 1 for sub, 2 for satellites, build in crossover and whatever EQ they've built in, so really only functional if used "outside the box" . . . the sats for the system are long since destroyed, so its really just being used to "make noise" in the basement. The receiver is an old Pio 411. I've still got one of these running the works in the living room. Its okay. The reason I say "crappy" about this particular one is because on of the mains channels is burnt (from a long ago experiment; in hind sight, I see it was basically trying to EQ a ton of bass into what looks to have been about as 1Ohm load; big no-no ;-p), so I'll be having to set it to 5-channel stereo mode and us the satellite channels for stereo amplification here . . . basically just going to be used as a workhorse experimentation unit till I just use it up.

I know the Durabrands are likely junk. I'm not looking for absolute SQ here, nor am I looking for driver advice. If I had a budget, I know what I'd want and I wouldn't be making so many compromises (and I wouldn't be spending it on this tertiary basement system; I have two different systems up in the "civilized" parts of the house that could use that sort of lovin'). Its an experiment, that may or may not happen, and if it does, I'm not likely to purchase more than a pair of drivers at any given time. What I'm looking for here is technical and/or experiential input on what sort of behavior I can expect from putting 5.25" FR drivers in OB (U baffle) lines like this. I can phase plug mod these drivers easily and cheaply enough (I have come up with a way to quickly make a plug for pretty much any driver for maybe $3-$5 each depending on the size, and since these look to have a tiny voice coil, it should be on the low end of that). I can experiment with attenuation of the back wave (likely a necessity in my raw concrete room). I can add in cheap tweeters if there's realy no top end (I need at least to 16khz, probably, to be satisfied). I'm not terribly interested in ordering drivers for what is basically a disposable project as shipping costs have gotten out of hand and speakers are not light items (would totaly suck to pay $9 to get a crappy $9 driver shipped, especially if you want to use 16+ of them, don't you think?)

Will I be able to run them without a sub (this is my preferred method by several orders of magnitude, even if I'm missing the bottom 1-1.5 octaves; any more than that and I'll be forced to use a sub; could be a deal breaker)? Will the combing just sound ridiculously bad (I've never heard the effect myself, and this system will not be used for critical listening)? Basically, will this be fun enough to spend $160-$200 on over the next several month on it, or should I just scrap the idea and head back to the drawing board?

Thanks,
Kensai
 
I was thinking of working up to short lines of 4 drivers, maybe possibly working up to 8 drivers per side long term. I thing I'll need to damp the back wave on the U baffles a bit to cut down on the raw concrete ring. I know I should be getting some sort of combing artifact, but I've never heard this for myself before.

Kensai,

Take a look at the simulation I’ve attached with point sources. Draw your own conclusions.
You will never get better summation from real drivers especially for frequencies over 2 kHz were the drivers are already beaming.
 

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Hi,

Just a thought :

Use 5 drivers per side. Wire the bottom 4 in series parallel.
Then 1st order series crossover them at the baffle step frequency.
Remove the centre cones and add cheap mylar super tweeters to suit.

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=290-010

Using 5 of the above, and converting it to a closed back vented box
with an EBS (extended bass shelf) alignment would give decent bass.

:)/sreten.
 
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