Professional stage speaker as a Sub for my HT (1 Viewer)

[Brad-F]

I am in the process of planning my first home theater.

When my dad passed away about 3 years ago, part of my inheritance was his professional bass gear. My dad was a bass player/singer.

He had this huge (almost the size of a fridge) speaker box. In it are two 15" JBLs bass speakers.

I don't want this fridge sized thing in my home theater, however I am wondering if I could get one of these speakers, put it in an appropriate box and use it for sub duties in the new system.

I also have his 800 watt power amp and a preamp that I could set up as well to run it.

This thing would have more than enough bottom end and volume, but I am wondering if it would do an acceptable/musical job in the home theater.

And if it would, does anyone know where i can find a plan/diagram for the new box. I am quite happy to build it myself.

 

[JakubH]

Well there have been some DIY projects with big JBL 15" prosound woofers, but there's no way to tell unless you have the Thielle-Small parameters for the woofers. The model number of the woofers would be the best thing to find out first, then you can do a search for the T/S parameters.

 

[Brad-F]

JakubH

I'll take one out on Sunday, have a look and post it's details here. Thanks for your response.

Brad

 

[JasonMA]

You sure you don't wanna just put the whole thing in your HT? I know it's big and all, but that thing would seriously rock your house for movies with that amp.

I had some old RE-38 series JBL's with 15" woofers left over from my old stereo setup and when I put my first HT together I used one of them with my old receiver as the amp and it did a pretty good job. Maybe just set it up temporarily until you finally get all of the materials for a DIY sub, though you may not want to take that thing down once you hear what it can do.

Anyway you play it, you'll have fun just experimenting. Good luck and welcome to the world of home theater.

 

[Brad-F]

JasonMA

Believe me, if it was just my place, I would be happy to do just that, and put the box as is, in the home theater room, for a time anyway.

But my girl, who is buying the house with me, wants it all to look nice. So I have told her I will build a new box (or two) for the speakers, and finish and stain it up nicely so it looks good in the room and matched the rest of the furniture and the general look of the place. Personally, I want it to look good too so I am happy to do that. The 'look' of your home theater is right up there with its functionality, isn't it?

I should however get a chance to try it all out before I pull them apart. I am looking to get the HT amp sooner rather than later. Maybe it will just sound so good, we will be happy to put up with the big ugly black fridge sized thing. Somehow, i doubt it.

 

[JasonMA]

LOL, it's always the girlfriend isn't it? I know man, I'm married, so I've been there.

Well, in any case, having a single 15" sub, or dual 15's if you really want some serious bass, should be more than enough. The "Frig" sized sub would definitely be too much. Let us know how it all turns out.

 

[Steve Lucas]

It's been my experience that stage subs for live music are designed for Db's at the expense of extension. They may play very loud, but I'd be suprised if they extend below 30Hz. That's somethng else you may want to check out when you are looking for specs.

 

[Wayne A. Pflughaupt]

Brad,

You might want to get a test CD and take some measurements. You'll probably find it falls like a brick below 40-50Hz - as is the case with most 2-15 bass cabinets. Sure, with 800 watts it'll "rock the house" as Jason mentioned, but you won't be getting much at all of the bottom octave.

Regards,
Wayne A. Pflughaupt

 

[Chuck Schilling]

Yep. Remember that these are designed for hard use as PA speakers - to generate tons of DB's per watt and to be basically bulletproof and to be able to withstand amp clipping and environmental anomalies you won't see in your home (spilled beer anyone?). I for one wouldn't think they'd make very good speakers for home use at all.

 

[cabreau]

Sell the bass setup to a bass player and use the money to buy a sub that was designed for HT. Like an SVS.

 

[Brad-F]

I just opened the bin and took out one of the speakers.

Signature Speaker - 15" JBL Model D130F.

The power amp is a Harmon Kardon Citation Sixteen. I think it is infact 1200 watts and not 800 as I had posted above.

I can't find on the net a chart showing the frequency response of this speaker, but I have found lots of historical data from way back in 1967 when this beast of the thing was first released.

Anyone here know more about it, and it's usefullness for a home theater?

 

[Dan Hine]

Alright, I found some TS parameters for you. The complete list can be found here.

But here are the only ones you need to know to know to see if it would work well as a home sub.

Fs = 40hz

Xmax .76mm (I'm assuming that's one way but even so, that's definitely NOT what you want in a home theater sub woofer). You'll kill it quick. And yes I checked and re-checked that it was in fact .76mm...

I'd say unless this item has significant sentimental value you should sell it...but keep the amp if it's in working order. That will come in handy!

 

[Chuck Schilling]

Dan, interesting info. As a rule, guitar loudspeakers (and this JBL is just that - a big guitar loudspeaker) are voiced for midrange frequencies. That's why no effective output below 40 hz - there isn't a need for it for the applications these loudspeakers are designed for.

On the plus side, these JBL drivers are in great demand by musicians, and he should be able to sell them on eBay or elsewhere for a pretty nice price.

 

[Brad-F]

Thanks Dan and everyone else that has contributed to this thread. I have learned so much and hopefully the info here will come in handy for others in my position.

I will sell the whole box. I'm sure dad would be happy with what I intend to do with the money made from its sale. Then hopefully get enough to fund the new sub.

Also. As Dan pointed out. The AMP could come in very handy. I'll keep that to power an amp-less sub.

Another thing worth mentioning, is that I have a friend, who is one of those audio gurus, who has installed several Home Theaters, runs his own band PA, mixes sound, makes his own speaker boxes and fixes his own amps. He has offered to build me a sub box or two (should I need two) for "mate's rates" (nice price). I was keen to do it myself, but since he offered....

So I'm thinking this will be my approach now. Use the Harmon Kardon to drive a sub (or two) in home made boxes with appropriate drivers.

Can you recommend some good drivers? Some that can handle the 1200 watt behemoth Harmon Karvan power amp and go down to the depths and quality required by a home theater?

I'll be sure to post the development of this sub (and the whole speaker system) here.

Thanks again.

Brad

 

[Mark gas]

check out www.adireraudio.com www.stryke.com and Link Removed for drivers. At what ohm does that amp put out 1200 watts? I'm guessing 4 or 8 ohms.

 

[Brad-F]

Mark

It says on the back, 8 ohms.

Cheers

Brad

 

[Wayne A. Pflughaupt]

1200 watts at 8-ohms? Holy cow, it must weigh a couple hundred pounds!

 

[Chuck Schilling]

Wayne, I think Brad might be mistaken. I checked H/K's site, and the documentation for the Citation specifies that it is rated at 150 wpc and weighs 55 lb.

http://manuals.harman.com/HK/Owner%2...tation16OM.pdf

 

[Wayne A. Pflughaupt]

Wow, that think looks pretty old. I'm surprised they had a manual up for it! Also surprising that Brad's dad was using a home audio amp for "professional duty" in his bass rig. Must be quite an amp, even if it is only 150 watts.

Regards,
Wayne A. Pflughaupt

 

[Brad-F]

I could be mistaken, as my level of experience with amps is 0, despite the fact that I worked for 25 years as a drummer in bands all over Australia. (Let the drummer jokes fly)

The amp does weigh a ton. (55 pounds I guess)

It does not look like the one in the link that Chuck sent around.

To start with it is an all black unit, basically the same shape as the on one in the PDF but different. The two knobs are in a different places, and the writing on the thing says "Citation Sixteen", and not "Citation 16". Finally, it does not have those dotted graph looking things on the front of it. The front of it is a clean flat black plate, with just two knobs, a power switch, and a light.

Might be just a US/Aust model difference thing so I suppose it could be the same unit.

And it does say 1200 watts and 8 ohms on the back .

Surley this thing would not weigh so much if it was a 150 watt amp, would it?

I'll check it out tonight and take some photos of it and put them up somewhere for you guys to see.. Should be up some time tomorrow.

If it IS the same amp that is in the pdf, would it still do for running a sub in my home theater?

Brad