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I was intending to try open baffle bass but the more I look at driver options the less sure I am of myself. In particular, it seems that if I invest in the drivers (I figure a minimum of four are required) and decide I don't like it, the drivers won't be useable for other options and I can't really afford that. I'd rather go with pro-audio drivers, and quality ones at that, and none of them seem all that well suited to open baffle bass. So I wish to consider other approaches.Now of course bass reflex will do the job but that would be my last choice. Will a true front loaded horn handle that range? If not than what design would y'all advise? Maybe a combo FLH with bass reflex for the bottom octave (like klipsch does)? I don't know speaker terminology so speak in small words please. I am sure there are options I am too ignorant to be considering. Maybe the Karlson? I dunno and need some help guys.
Oh, efficiency doesn't matter, as I will tri-amp with active crossover. And I hate loose, wooly, flabby bass. Typically, in the good old days, I'd prefer an acoustic suspension speaker. Aperiodic is fine though. But I really want tight, punchy, articulate bass with some slam so I am thinking I want horn loaded. I really don’t want a separate sub-woofer and don’t have to have that last octave. Mainly I listen to rock/jazz/folk music and my room is moderate in size. Rest of the package is open baffle mid from 250-1800 and compression driver w/wave guide from there. Too bad I lack the tools and joinery/cabinet skills. Now if I could only weld them up out of 1/2" plate steel:)
Follow Ups:
Russ,Bring the little black ones back, and come get these dual
12" emminence jobs. Get Steve to bring his truck. The entire front baffle board comes out with the drivers still intact upon a dbl thick front plate. Make some back wave supports, and use your winged job for the front wave. IF you don't like that sound, THEN i'd reccomend a vibration cancellation approach, since you'd already have 2 drivers per side. I'm going to miss my "Monster Sound" (as Steve calls it) but, i gotta get my ass outa this town.
I'll explain the V/C enclosure on the phone, it's a lot easier than typing.p.s. these drive units have a low fs for a pro unit, a high BL factor and plenty of X max. I got 'em for half price , and you can have them then again another 1/2 off.
scott
p.s anyone else in palm beach or broward county want some HUGE
subwoofers? they go deep and ARE NOT WAF.
Steve's truck is dead! But we will work things out. I was kinda hoping you would email me about driver parameters. Sounds like we are in a place to help each other so thats great. I'll call you soon....weekend at latest.
Onken bass enclosure with ALtec 416, good enough for Jean Hiraga...
If you want to use 4 drivers the Onken W seems like a fun project:
http://www.melaudia.net/remOnken.php
Then you can work on a horn for the 250 to 1800hz range :-)
Id complicate it,have a ~1m deep simple flare(approximation of an exponential) 80hz - 250hz straight horn.See volvotreter.deThen sub of choice in a corner or similar,could be a multiple driver sealed unit,or folded basshorn ~800L in volume.
Mike.e
There are three constants in life: death, taxes, and the inevitability of a (speaker)wire thread being closed -SY
Relatively few prosound woofers will give you honest 30 Hz extension in a reflex cabinet without significant boundary reinforcement from nearby walls, and I can't think of any that would even come close in a sealed box.About a year ago I was working on a speaker that would go down to 30 Hz ballpark in a large vented box using a prosound woofer. The woofer that seemed best suited to the task was the Usher 15" PA woofer. It worked great in the bottom end; trouble was I wanted to cross over at a minimum of 1 kHz. I found that up that high, the midrange was less articulate than what I could get with a prosound woofer having a shorting ring in the motor structure (which the Usher didn't have). But down around 250 Hz, I don't think there would be any audible consequence from not having a shorting ring. In fact, a 600 Hz crossover worked fine on the woofer's side - but my horn wouldn't go that low. The project is on a back burner for now as I'm barking up other trees.
So anyway my suggestion is the Usher 15" PA woofer in a vented box. In a 300 liter enclosure tuned to 30 Hz, it gives you an honest -3 dB at 30 Hz. My recommendation would be tune to 27 Hz as that's the lowest fundamental of normal orchestral instruments, and if possible bump the box size up closer to 350 liters.
Duke
You mentioned you picked up the 18sound waveguide (I assume the xt1086). If you have had a chance to try I'd be very interested in what you thought. Also I downloaded their catalog yesterday and they now offer a 2" entry waveguide which might better meet your needs. I have not seen nor heard it though.
I bought a set of 18Sound 1086s but probably won't be using them soon after all. Looks like the DDS waveguide will be available once again in a couple of months.Duke
Now if I could find an affordable horn for say....200 to near 2khz. I guess I am feeling a little defeated by speakers. I need a benchmark to judge my efforts by.Maybe someday you more experienced guys could put up a list of (under $300) drivers that are known to sound good and are forgiving of cabinet/crossover design.
Hi Russ,Using a horn as the bass solution for 30-250Hz is a very ambitious goal. A front horn for that range is going to be huge, as demonstrated by Peter. There are also integration issues. The reward of getting a bass horn to sound right may be high, but the cost is pretty high too. For most people, box and OB are perhaps more practical options.
As to driver selection, as long as you don't go for something with an ultra low or ultra high Qts, I actually don't think it is an issue. In this regard, I always feel that the "need" to use a high Qts driver for OB is way overblown by the FR community, mainly due to the reluctance to deal with the supposed complexity of EQing. To me, EQing is pretty much an inevitable aspect of OB bass. Once you accept the use of EQ, there are many nice prosound drivers you can use for OB. If you pick drivers designed for a sealed or reflex box and put them on OB, you can EQ them to get the desired bass response. If you don't like the sound of OB bass, then you still have the option of putting the drivers in boxes.
As to "loose, wooly, flabby bass," based on my own experience, that is not an inherent problem for OB bass. In fact, when I was playing with the Fostex FE206ESR on OB's, I preferred the bass generated by two cheap 15" drivers (Qts of around 0.38) on each OB to the bass produced by a pair of JBL 4648 boxes that have two 15" JBL 2226 drivers in each vented box. It could be mainly an integration issue. Also, I've heard bass generated by Dr. Edgar's bass horn and the LAB12 horn. I liked the sheer power of the horns, but I don't think horns are the only way to get "good enough" bass.
Best regards,
Thanks Kurt. I guess I was getting "cold feet" without good reason.Now of course I can just buy an EQ and add it to the signal chain. But I'd rather not (for dumb ass tube purist type reasons that may change). I suppose I can put an inductor in series with the woofer and use an active set at 250 hertz and/or a plate amp with a built in bass boost. But maybe there are better ways that I am over looking?
Can you advise on a driver that you have had good luck with? Ideally not too bad in price and I'd like to get by with no more than two drivers per side....or maybe even one 18"??? Actually the dayton RSS315HF-4 keeps catching my eye (part# 295-464).
Russ
Hi Russ,To handle the bass, if you don't intend to deal with room modes, a simple and cheap 31-band analog EQ will do. Two friends of mine tried that approach, and they were both happy. I myself was using a digital 31-band EQ (Behringer)for the eight-18"-driver dipolar bass to dial in the needed boost. It turned out that I only needed 6dB at most. Alternatively, you can use the Behringer Feedback destroyer (e.g., DSP1124P) as those Inifinite Baffle (IB) bass guys do to EQ the bass. That will allow you to deal with room modes in addition to providing bass EQ. Either way is inexpensive and quite easy.
If you want to build your own EQ circuit, you may want to consider doing it at the line level, so that you don't waste the amp power in the big coil. For instance, you can put a passive line level low-pass between the active crossover output and the plate amp input. Such an arrangement will not, however, have the flexibility of fine tuning the bass response, and in many cased may provide too much or too little bass boost, depending on the driver/baffle combination.
I have had good luck with cheap 15" and 18" woofers that I got on clearance sales. I've never tried the JBL 2226 woofers I have on OB's (becuase their Fs is too high and Xmax too small for my taste) so I cannot say whether expensive woofers are better for OB application. I think that most decent woofers with sufficient Xmax should be able to provid decent OB bass. I myself would choose the Dayton IB 15" woofer if I need new woofers for OB, but that driver is not suitable for sealed or vented boxes so may not be what you are looking for. I really don't have other particular drivers that I would recommend. I've be happy to use any good-quality pretty-looking woofer with a decent Xmax, low Fs, and large surface area, as long as they don't cost too much. Woofers are just tools.
As to the the Dayton RSS315HF-4 woofer, it is a 12" driver. One thing to keep in mind is that it is easier to get good bass quality if you have a large moving surface area. A 12" woofer has only about half the moving surface area of a 15" woofer. For not much more money, why not get the 15" DAYTON RSS390HF-4 woofer?
Best,
Kurt
If efficiency doesn't matter, and since you like acoustic suspension speakers, the solution seems to be straightforward.Get two mid-Qts 15" pro bass drivers with low Fs, and good midbass preformance. Build two sealed cabinets 200-300 litres in size.
...and you're sorted.
You'll probably have about 95dB efficiency and a -3dB point of maybe 45Hz, but that's heaps for what you need: rock/jazz/folk music in a moderately-sized room.
"I really want tight, punchy, articulate bass with some slam"
==> punch and slam are about the midbass. You don't need a 30Hz bottom end to give rock music punch and slam. Live rock shows (almost always) use sound systems that roll off above 30Hz.
Hi Russ57,I have attached som pictures of my system which uses front horns bass horns from 30-266 Hz which is very close to the frequency band you are interested in. The horns are each loaded with double 15" drivers to make the horns shorter, but as you see they are large. The only way to make such horns take up less space is either by folding them or by putting the mouthts in corners.
Quite a few people use corner horns up to 250 Hz, so if you have solid corners this may be an option. Otherwise GM'suggestion is probably the way to go. With the right drivers bass reflex systems do not have to be fluffy sounding. For instance I am quite sure the the bass reflex systems by Bert D. using light cone drivers sound very good and fast:
www.bd-design.nl
Happy hunting!
Regards
Peter
Greets!Yes, a FLH can do it, but it will be quite long if not carefully folded or use multiple drivers to truncate it. I've tried several paths and kept coming back to dual HE 15" with low Fs, Qts in a large, simple cab tuned well below the passband and use EQ and the room to help with the > ~80 Hz BW since I never minded using as much power as required. Combo cabs were fine back when there was little source material below 70-80 Hz, but speakers like the A7 are woefully inadequate for such a low Fb unless you use mass quantities of EQ to flatten them in-room if not corner loaded, defeating much of the reason for using them in the first place.
Actually, if you're a welder/metal worker and don't mind the weight, metal cabs are the 'Hot Ticket' since their Fs will be above the passband and only minimal damping will be required to quell any reflections back through the driver.
Nothing constructive to add apart from $0.04 of opinions.OB bass probably won't do slam / punch . They would probably integrate well though.
A normal karlson K-15 won't do an honest 30Hz (would probably work well from around 45/50Hz - 200Hz). I can't speak for re-tuning as I've never tried that.
Your midranges probably don't drop like a rock below 250Hz, so assuming you implement this bass solution in stereo (probably a foregone conclusion), .. you could probably cross over a little lower (closer to 150Hz) and allow the overlap to fill things in.
A horn would work (if you can build it), but the devil's in the details ie. not losing the midbass during integration, level matching, physical size (though corner loading would help). Might be smaller than a bunch of sealed boxes though.
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