-
Please note that there are a few updates and clarifications made in the Audiokarma Rules, mostly relating to advertising and the addition of the new "Paying it Forward" & "Giving back" forums in the AudioKarma Audio Marketplace section.
True “full range” floorstanding speakers
- Thread starter AudioGMan
- Start date
Harvestor
Addicted Member
DESCRIPTION
Model 380SE Specifications
DESCRIPTION: 15†3-Way Loudspeaker
FREQ. RESPONSE: 25Hz –20kHz
POWER HANDLING: 5/405 Watt RMS (Min/Max)
SENSITIVITY: 102 dB (1 Watt @ 1 Meter)
IMPEDANCE: 4 Ohms
LF DRIVER: 15†die-cast frame / 2†voice-coil
MF DRIVER: (2) 7†Cone
HF DRIVER: 1†voice-coil horn tweeter
CROSSOVER POINTS: 250 Hz/3500 Hz
PROTECTION: System Fuse/2.5 Amp Slow-Blow 3 AG fuse
HF Driver Self-resetting PTC
MSRP: $540 ea
CIRCA: 1985 – 1991
Model 380SE Specifications
DESCRIPTION: 15†3-Way Loudspeaker
FREQ. RESPONSE: 25Hz –20kHz
POWER HANDLING: 5/405 Watt RMS (Min/Max)
SENSITIVITY: 102 dB (1 Watt @ 1 Meter)
IMPEDANCE: 4 Ohms
LF DRIVER: 15†die-cast frame / 2†voice-coil
MF DRIVER: (2) 7†Cone
HF DRIVER: 1†voice-coil horn tweeter
CROSSOVER POINTS: 250 Hz/3500 Hz
PROTECTION: System Fuse/2.5 Amp Slow-Blow 3 AG fuse
HF Driver Self-resetting PTC
MSRP: $540 ea
CIRCA: 1985 – 1991
AudioGMan
Well-Known Member
Yes I’ve seen that design. I’ve built an open baffle before. But every single driver open baffle I’ve ever seen needs the help of a separate subwoofer for the lower octaves. They don’t do 20Hz-20kHz +/- 3dB.
AudioGMan
Well-Known Member
Well they claim 25Hz-20kHz +/-3dB for the 380SE and then at the bottom of the page it states “Low frequency limits determined by room placement.” Isn’t that the case with any speaker? What is the tuning frequency for the 380SE?
AudioGMan
Well-Known Member
I get what you’re saying. So what if one uses a 15” or larger subwoofer driver in a big sealed cabinet and then cross it over at 200Hz to a fullrange driver?
Just checking some of the speakers that I own that will go well into the 20hz range with less than 2 db swings they cross over very low, case in point is the Infinity Kappa 9's which has their bass drivers crossover at 80 hz. The Infinity QLS-1's use a dual voice coil bass driver and the specs are 18hz +/- 2db and their crossover point Is 200 hz. The QLS-1's bass is much better IMO than the Kappa's. I think it is primarily due to the larger cabinet size, and the Watkins driver. The Kappa's cabinets has less volume and the Kappa's use double the drivers in a small cabinet.
Don't know the specs of the Phase Linear Andromedas but the bass is very good on them, even compared to my Infinity's They do use a stand alone bass commode, with dual 12 inch drivers firing down which are mass loaded.
Don't know the specs of the Phase Linear Andromedas but the bass is very good on them, even compared to my Infinity's They do use a stand alone bass commode, with dual 12 inch drivers firing down which are mass loaded.
z-adamson
Addicted Member
If I really wanted to do this I would use something like a Dayton utilimax 18 (one per side) in whatever enclosure gets the job done. My gut tells me a large ported enclosure would be ideal, but i could be wrong. I would get an active 2 way crossover and two amplifiers and 1 preamp. Set the crossover low....like 70hz or so. Use your mach three or something similar that suits your taste. 70hz and up to the mach three, 70hz and down to the subs.
I am doing something similar. Peavey low rider 18 and hpm100. DIY 9 cubic feet cabinets, ported. Does not go as low as what you want, but low enough for me....about 30hz.
AudioGMan
Well-Known Member
What I’m trying to avoid is using more than one pair of cabinets and one amplifier.
AudioGMan
Well-Known Member
I have four brand new still in the box 12” Blaupunkt GBW120 subwoofers that I bought months ago. They are single voice coil 4 ohm drivers intended for car audio use. My intentions are to build two separate sealed cabinets about 8 cubic feet each with a pair of the drivers wired in series in each cabinet. The drivers will probably be oriented side by side so the speaker cabinets will be roughly 3 feet wide each. The front baffle would extend above the drivers and become an open baffle for either a 6-1/2” or 8” fullrange driver. The center of the fullrange drivers will be 34” from the floor putting them at seated ear level. Then I will build a two way 200Hz 12dB/octave passive crossover for each. So basically it would be a two way speaker each consisting of two 12” subwoofers and a single fullrange driver. Does anyone see any problems I might run in to with this idea? Any input is welcomed.
z-adamson
Addicted Member
I have never heard a subwoofer sound any good above 100hz, 24db per octave. At 200hz, 12db per octave, you are well into directional territory and things start sounding wonky. in other words, it will sound like crap. To do this you will need WOOFERS capable of playing up to about 600hz cleanly. But there goes your sub bass. On top of that, two drivers, side by side playing directional frequencies creates all kinds of problems. That's why you want/need non directional frequencies only coming from side by side, active drivers.
z-adamson
Addicted Member
Why?
donprice
Wound up workin' at a gas station....
Does using 6 channels of an obsolete 7.x AVR for an active crossover 3-way system count as using one amplifier?
AudioGMan
Well-Known Member
Wh
Why? Because that’s what I want. A pair of speakers that are full range. Why does that seem impossible? Okay so if I had to use a woofer that can play from 20Hz to 100Hz then cross over to either a fullrange and make it a two way or make it a three way crossed over to a mid and then a tweeter. I don’t see why people would think that’s so hard to do. Driver technology has improved substantially over the past 50 years. Sometimes you just have to build it and see what happens. You can’t just assume that something is gonna sound like crap. There’s speakers that have two woofers side by side playing the same frequencies that are crossed over higher than 200Hz. I know there’s a JBL model like that. And every speaker I’ve seen with 15” woofers is crossed over higher than 200Hz between the woofer and midrange. A lot of floorstanding speakers with 12” or 15” woofers even have crossover frequencies above 1kHz between the woofer and mid. So I don’t see why having two identical 12” woofers wired in series and operating side by side would be any different than having a single 15” or 18” that’s crossed over at at 500Hz to 1kHz. All frequencies above 100Hz start to become directional. Are you saying that a speaker that uses a 15” woofer such as the Cerwin Vega 380SE and is crossed over at 250Hz sounds like crap because the woofer is playing into the directional frequencies? I guess that means pretty much any floorstanding speaker sounds like crap because the woofer plays above 100Hz.
Last edited:
AudioGMan
Well-Known Member
When I say one amplifier I mean two channels. A left and a right channel.
frommerstop
Super Member
As I suggested earlier, KEF R107s will do exactly what you’re asking for. They reproduce, in a normal room, 20hz-20khz +/-2db and require only a good single amplifier of 100+wpc into 4ohms. They are not particularly expensive on the used market, and Aren’t particularly critical of placement.
It’s hard to imagine a better suggestion than that.
It’s hard to imagine a better suggestion than that.
Rob-F
Likes Vintage Gear and DIY
The time: mid-1950's. The place: Miami, Florida. I think the dealer was called "Hi-Fi Associates" on Biscayne Boulevard. I used to hang out there. Rudy Bozak brought down a one-off speaker system he had put together. It was enormous. It had, I think, eight of the 12' b-199 woofers. Two of them had long-throw voice coils. I watched Rudy wind them in the back room. He played a recording of an airplane taking off. I have no idea of what its frequency response limits were, but at the low end, at least, it was pants-flapping. Of course, the Bozak tweeters weren't designed to reach 20,000 Hz.
Last edited:
swechsler
Frog Whisperer
It's not impossible but it would be a lot more difficult than to build two cabinets per channel, because you're going to need two subenclosures (one for the subwoofer, one for the woofer, the former of which will probably be significantly larger than the latter), both tuned to that specific driver. It's also going to make them very heavy. It's been done - take a look at the Infinity Kappa 8 and 9 as two commercially-made examples (the midbass driver is an unusual dome rather than a cone, but it still uses a low-pass crossover frequency of 90hz, not bad for a subwoofer's high-pass cutoff point), but neither of those models go as low as you're looking to go, and they're already quite heavy.
z-adamson
Addicted Member
Are we back to talking about hifi woofers or are we still talking about low end car audio subwoofers designed to be crossed over at 60hz used as hifi woofers crossed at 200hz?
z-adamson
Addicted Member
Good luck, have fun