And Now For Something REALLY BIG

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I really love the videos of HUGE JBL's and big ol' Altecs on various sites. The sheer size of the cabinets and visceral presence of the sound they seem, and are reported to produce is intriguing and 'lust worthy'. Especially the big 4350 & 4355 and Kenrick Sounds own 4351 (a vertically arranged 4355)

There don't appear to be many projects on the scale of these $$$$$ giants, and understandably so with WAF, room size and cost etc to be taken into account. But what if..............?

Maybe 2x 15inch Eminence drivers for bass up to 100-150hz, a decent 10inch mid (recommendations?) up to 1000-1300hz, then maybe a paudio 2 incher on a 2380 cloned horn up to 8khz-9khz & then ??????????

How could it be done for a reasonable price (comparable to the JBL's)? What design concerns are there with HUGE 4-ways (assumed active)?

Let your juices flow in a mental exercise in excess - you never know, someone might build it?
 
The Celestion TF1020 is a fine 10" midbass/midrange at its price point with plenty of sensitivity. There was a great deal last year at Mckenzie, for 40$ each. The 16ohm version can still be had for this price at Avatarspeakers.

I don't know enough about these JBL designs to really know what to go for, but it seems like you are describing a 4-way. The Xover might end-up being a large chunk of the final expense. Most 2" compression drivers seem rather pricey, even the cheaper ones like P.Audio. Maybe an Eminence PSD:2002 could do the job well in this frequency range, especially with the TF1020 as a midrange, it plays clean much higher than where you'd cross over. Art Welter was impressed with its "low"-frequency performance (PSD:2002) and distortion figures in a recent elaborate CD shootout.

IG
 
I don't know enough about these JBL designs to really know what to go for, but it seems like you are describing a 4-way

Yeah I thought 4-way to allow drivers to be used to their ultimate best freq range. 3-way is still cool as long as the drivers are capable of covering the bigger freq spans.

This flight of fancy is to try to have an enclosure similar to the 4355 (horizontal) & 4351 vertical)

The sheer impact & wallop of a 15incher in the bass and a 10incher in the mids seems a recipe for 'moving' music even at low volume
 

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I remember the VOT and others. Fine if you need to fill a stadium. Useless and pretty terrible sounding in a house.

The old rule of a decade still seems to be pretty sound. 20 to 200, 200 to 2K and 2K to 20K. About right for a nice 12 inch three way. The market in available drivers tends to the sub (20 to 80) a 5 to 7 inch mid-bass for 65 or so to 2K , and a 1 inch tweeter because that is 99% of the market. Really decent mids are very few. You just don't really need a 4-way in a house. Extra complication and cost for no real advantage.

Now, I am talking only about high quality sound. When I was about 14, I thought bigger was better.

The other thing I need to remind folks of. Unless you live in a stand-alone house, you can't use any bass below 50 to 60 Hz anyway without making a lot of people mad. I can't remember how many times here someone in an apartment wants to build those 15 inch subs! Low frequencies travel for miles and have no respect for the walls.
 
I have to agree with TVR's wisdom.

But I don't think it's the wisdom of those speakers that has you salivating. ;) You might consider a slightly scaled down version - 2 Emi Alpha12As for bass speakers, an Emi Alpha8A mid, and the Vifa BC25SC06 tweeter. The 12As need half the box volume the 15As do, the 8A will go bit higher with better dispersion than a 10", and the Vifa is well-regarded in the Stentorians. (keep in mind the JBLs were really meant for the studio, and the super tweeters were just there for judging tape hiss when layering tracks.)

But yeh, when it comes to impact, there's no substitute for size. :cloud9:
 
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Useless and pretty terrible sounding in a house.
Not necessarily the case at all.
I thought bigger was better.
A blanket statement but not necessarily untrue.
I have to agree with TVR's wisdom.
Me too, to a point.
But yeh, when it comes to impact, there's no substitute for size. :cloud9:
I knew I loved you.

Seriously though, it all comes down to the environment. No need to go beyond what is required to do the job. I realize that is somewhat subjective and you guys know that I believe in getting the job done whatever it takes when it comes to speakers. Many of you look at how I approach things and have a laugh. Not me, I'm all serious. :D
You can have a very nice sounding large system that you listen to at lower volumes most for the most part but is capable of stepping up to the plate when called upon. The other option, the one with the fewest compromises is to have two systems, one for critical listening and one for when you let your hair down, like Saturday night.

Tell us the dimensions of the room and any particulars about the environment and I'll tell you what I'd do.

Cheers. :)
 
re: "Maybe 2x 15inch Eminence drivers for bass up to 100-150hz" -that would make my juices flow, but the only prob would be the huge boxes needed. To get around this, for a while I've had at the back of my mind this idea for 2 x 15" (per side :D ) in sealed boxes + Linkwitz Transform...???
 
I was on a river cruise (Willamette, OR) in the late nineties, struck up a conversation with a couple, the conversation turned to music.....he was grumbling about some monster speakers that were taking up an enormous amount of space.....the speakers "inside" were broken (Rotted)......He wanted to get them 'outta' the house! I tracked down my wife & told her of the great opportunity........."Not more junk".......Needless to say I didn't track the guy down on the boat....You guessed it 4350.....He even knew the model ##

____________________________________________________Rick......
 
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The old rule of a decade still seems to be pretty sound. 20 to 200, 200 to 2K and 2K to 20K. About right for a nice 12 inch three way. Really decent mids are very few.

A 3-way as described seems cool, but couldn't the use of a nice horn from 1khz-8khz or so get around the lack of decent mid drivers? (Also making a 4-way necessary)

You might consider a slightly scaled down version - 2 Emi Alpha12As for bass speakers, an Emi Alpha8A mid, and the Vifa BC25SC06 tweeter........But yeh, when it comes to impact, there's no substitute for size. :cloud9:

A 'mini' version sounds cool. Is the Alpha8A good enough?

You can have a very nice sounding large system that you listen to at lower volumes most for the most part but is capable of stepping up to the plate when called upon.

That pretty much describes my ideal speaker:D

for a while I've had at the back of my mind this idea for 2 x 15" (per side :D ) in sealed boxes + Linkwitz Transform...???

Sounds interesting. I'll have to read up on the Linkwitz Transform.

..I don't know Japanese (at all), but I suspect the movers (just before unwrapping the 1st one) were saying something along the lines of: "you want us to put this where?"

I thought may - "You dropped over $10k for these beasties and you're using them as headphones?"

My speaker usage is odd. I on occasion take my speakers out on a day trip to a larger space for either a party or a mega listening session that I cant do at home. I think using the minidsp to cut bass etc at home and open it up when called for would be cool. So my ideal speakers could be used at home with great authority and clarity/detail at low levels but be able to open up when asked. Home listening is the priority thou for me. There's enough speaker knowhow here to shame many commercial companies. BTW guys, these are theoretical at the moment - a design exercise to see if it can be done - a large(ish) home monitor in the style of JBL.
 
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I like the scaled down JBL 4350/4355 idea - Lets start with the bass

A single 15inch driver is cool but twin drivers (12inchers maybe) have several advantages as I understand it (or don't :rolleyes:) It increases sensitivity, lowers distortion and increases dynamics

All good things - All true? how would it be best executed in keeping with the brief?
 
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Lets start with the bass

A single 15inch driver is cool but twin drivers (12inchers maybe) have several advantages as I understand it (or don't :rolleyes:) It increases sensitivity, lowers distortion and increases dynamics

one 18" is cool
2x 15" will ofcourse increase....

joke aside:D the advantages you list only have effect in midbass
2x 12" will have no advantage in low bass
if you want to know why, take a look at the nice looking B&C 12PS100 woofer...93db ;)
 
the advantages you list only have effect in midbass
2x 12" will have no advantage in low bass

now I'm confused :confused: Can you explain? - I'm learning all the time


if you want to know why, take a look at the nice looking B&C 12PS100 woofer...93db ;)

Eminence Beta 12------------B&C 12PS100
250w RMS--------------------700w RMS
47hz Fs-----------------------44hz Fs
0.46 Qts----------------------0.27 Qts
98dB/W@1m-----------------93dB/W@1m
4.4mm Xmax----------------8mm Xmax
£45.24------------------------£222.18

I can get 4 Beta 12's for less than one 12PS100. What is the REAL difference between 0.46 - 0.27 Qts? The effort is shared amongst 2 drivers so I'm asking less of an inferior driver and hopefully staying out of its danger zone. This wont overcome the Qts, but wont I have better control of the lower spec driver by pairing them up? I know a better driver is a better driver but £444 for 2 woofers is maybe a little :gasp:

Would a single 'good' 15 per side be better then?
 
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I on occasion take my speakers out on a day trip to a larger space for either a party or a mega listening session that I cant do at home.

Build it up as modules. Do the LF as a bin with the HF up top. That's how I would do 4350's. Don't do the sideways arrangement with the mid next to the midbass driver. Do a verticle they integrate better that way. If you look at the JBL Manual for 4350's it tells you you need 8-10ft for the drivers to integrate properly.

A single 15 will work fine. You have to remember 4350's were designed for max output and power handling. They were also Bi Amp only.

Rob:D
 
It is heartening to me to see BIG is coming back! :D

I myself have been working on a 'big' project, though more modest than many of those presented here. I live in an average sized house with a rather small listening room, but I too want something I can listen to at low levels most the time, but that can rise to the occasion when called upon.

My plan is for a big vented box of 7.5 cu. ft. volume. The drivers are:

Eminence 4015LF 15" This is a great driver that plays low but because of a light cone is still reasonably efficient. Great xmax and a shorting ring ensure plenty of clear volume.

B&C 6MD38 6.5" The problem with a large mid is beaming at the high roll-off. This can be overcome with a 2" CD that plays low, but that can get very expensive. This mid is very well built, again with a large x-max that allows it to play down to 300 Hz while maintaining high SPL, but because of it's size plays high enough to mate comfortably with a 1" CD.

I have also purchased a pair of D220Ti's but am working on finding the right horn, currently. :)
 
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