DIY JBL Speaker Cabinets and Components Question

[j_garcia]

Building a speaker is easy.

Building a good speaker is a different story

 

[Keith Roberts]

Keith,

I like ya, you've got motivation that's for sure; and, you might end up somewhere on the corner of Satisfaction Street and Frustration Avenue. Most folks undertaking DIY speaker projects want to restore something, don't want the expense of a speaker manufactures cabinets, or want a "sound" which cannot be fulfilled with factory stock. I'm not clear on what your objective is except for perhaps making a vintage impression with the Sansui serving as the center piece of your setting.

If I had your needs I'd get a pair of JBL Studio 590's and get some real wood veneer to cover the speakers vinyl MDF covering. You'd then have the sound you are after from the sort of power your receiver can deliver, and the sort of beauty the more expensive JBL Synthesis Speakers are coveted for.

Thanks so much. I was looking for a project my 14 year old son and I can do together. I figure with a great set of speakers which we built together, he would enjoy them a cherish them after I'm gone. My old landlord had a set of JBL C34's and I had 2 C35's myself hooked up to a McIntosh MC-240, a C-22 Preamp and an MR-71 tuner. But when finances became rough I had to part with all of my audio equipment back in 2004 except the Sansui. I'm in better shape now and would like to replace a lot of it if I can. But the DIY speaker project I would love to work in with my son. The Sansui is just what I have a present and since it's been restored it sounds pristine! As such, I would like to build of if it. Thanks so much! I'll look at those JBL Studio 590's. You may have something there!
-Keith

 

[Swerd]

Thanks so much! I'll pick up that Speaker Building 201 book and start there! Thanks for the information!! It's greatly appreciated!

Glad you found it helpful. Good luck with your build and tell us about any progress you make. We love pictures.

That Sansui receiver is quite the hoss! Was it easy or cheap it to get it up and running? Those large JBL PA-type drivers are very sensitive, so a 125 wpc amp should easily drive them louder than you could ever want.

 

[lovinthehd]

Thanks Bucknekked:
And yes, I love this Sansui. I also have a Sansui 5000a I am about to get restored and will need a speaker project for it too. I am certainly open for suggestions surrounding supplying my 9090 with a good set of speakers. I would like to build them myself but would certainly consider purchasing some store bought units as well. I would like to stick with JBL components however but again, am certainly open to suggestion. What I am looking for is a good bass reflex, similar to the JBL C35 but with more modern components. Any good designs? If you can even point me in the right direction I will appreciate that as well.
Thanks again Bucknekked,
-Keith

An alternative to consider might be a kit from diysoundgroup.com, not JBL but good stuff!

 

[Keith Roberts]

Glad you found it helpful. Good luck with your build and tell us about any progress you make. We love pictures.

That Sansui receiver is quite the hoss! Was it easy or cheap it to get it up and running? Those large JBL PA-type drivers are very sensitive, so a 125 wpc amp should easily drive them louder than you could ever want.

Thanks Swerd. My particular Sansui 9090 was built in 1977 and was relatively easy to get restored. I had it done by Jim at qrxrestore.com in Eugene, OR. The total with shipping was roughly $725 but well worth it. The unit comes back better that new. He does this thing to it called the Differential Current Balance Modification so the two output drives have all their capacitors, fusible resistors, and a bunch of transistors, changed, plus new parts added. The Differential Current Balance Modification or DIFF MOD requires installing a couple custom circuits that they make up, and two small 10 turn pots on the output boards. They then adjust some very small voltages while the unit is running. Then they set the offset and bias again, and then redo, again, the same adjustments. They then pull the pots, measure their value, and replace them with resistors that he makes up with two or three resistors, to an accuracy of 1 ohm. This achieves balance in the input circuitry, which is very important. All 93 capacitors are replaced with high-end Nichicon Mylar Film capacitors. Everything is gone over! Complete tear down! This Sansui will last another 40 years without a problem. I have a Sansui 5000A I will be sending him soon. Roughly the same price but the 5000A is $475 plus another $125 for the DIFF MOD but again, the unit will last another 48 years as mine was built in 1970 and has not really seen the shop much. A good cleaning of the pots here and there to get the scratchiness out of the controls.

I am still undecided about the JBL 2226H however. I may just go with the E-130's. I found a place called Jammin' Jersey out of Northridge, CA online which sells lots of the vintage JBL components. Their address is jamminjersey.com....I think. Great selection. Roughly the same prices as eBay.

Anyway, thanks for the advice Swerd and I'll be sure to post pictures as we progress!

-Keith

 

[MrBoat]

Since you're at a point of indecisiveness and have spent so much on the unit you have already, why not a pair of vintage Sansui speakers that need work? I have a pair of SP-X8000 that are/were my brother's that I have stored here for years. In spite of what some purists might inflict on speakers like these, I remember them sounding pretty darned good.

You never know. There may be a bargain lurking on your local crgs-list that needs some minor, yet satisfying work. At least to get your feet wet and to keep with the Sansui theme.

 

[MrBoat]

Keith
There are a number of DIY threads here and a healthy population of builders. MrBoat (look him up) is a avid DIY builder AND a JBL fan AND he actually builds boats so he's a doer not just a talker. I like your idea of building out a set of vintage (as much as possible) JBL's to go with your Sansui. I think the trick will be getting everything matched up so the end product sounds great. MrBoat has done it so I know it can be done. He can give solid pointers and advice that you can bet your hard earned dollars on because he's built the stuff and it works.

That's awfully nice of you, Buck, but truth be told, I am a DIY train wreck waiting to happen at any given moment.

It's the folks here that pointed me in good directions or that could at least read thru my 'special' needs.

 

[Swerd]

… but truth be told, I am a DIY train wreck waiting to happen at any given moment.

We've seen the photos of your DIY work. Your idea of a DIY train wreck includes track with welded rails, and a train system that runs on time .

If your work is a train wreck, it leaves little room to describe the work the rest of us do .

The OP of this thread had some ideas for his speakers that trouble me a bit. He wants to use enormous, expensive, and very sensitive 15" JBL woofers, the 2226H (97 dB at 1 watt) or the E-130 (105 dB). They would make good PA system or guitar amp speakers, but are (IMO) poor choices for a home audio system. They require large ported cabinets, but will only produce bass down to about 50 Hz. They may be loud enough to remove all body hair and clothing on people 50 yards away, but they will lack bass. He seems determined to spend money on his "dream speakers" so I didn't try hard to talk him out of them. If he comes back to AH, maybe your experience with building the Tempests, and your obvious DIY chops can help change his mind.

 

[MrBoat]

We've seen the photos of your DIY work. Your idea of a DIY train wreck includes track with welded rails, and a train system that runs on time .

If your work is a train wreck, it leaves little room to describe the work the rest of us do .

The OP of this thread had some ideas for his speakers that trouble me a bit. He wants to use enormous, expensive, and very sensitive 15" JBL woofers, the 2226H (97 dB at 1 watt) or the E-130 (105 dB). They would make good PA system or guitar amp speakers, but are (IMO) poor choices for a home audio system. They require large ported cabinets, but will only produce bass down to about 50 Hz. They may be loud enough to remove all body hair and clothing on people 50 yards away, but they will lack bass. He seems determined to spend money on his "dream speakers" so I didn't try hard to talk him out of them. If he comes back to AH, maybe your experience with building the Tempests, and your obvious DIY chops can help change his mind.

I meant more of the science of it all or choosing the right things like with the OP. I got lucky in a number of ways. Mostly because of the diversity and experience that resides on this forum. It allowed me to take what little I did know, and build a custom, long term system for my specific situation without sacrificing quality.

I still can't believe what I ended up with for how little I actually spent, and spread out over a decent amount of time. Just the entertainment factor of that journey considered, it's already paid me back.

Thank you for the nice compliment, and for helping a fellow audiohead out!

 

[Pogre]

We've seen the photos of your DIY work. Your idea of a DIY train wreck includes track with welded rails, and a train system that runs on time .

If your work is a train wreck, it leaves little room to describe the work the rest of us do .

The OP of this thread had some ideas for his speakers that trouble me a bit. He wants to use enormous, expensive, and very sensitive 15" JBL woofers, the 2226H (97 dB at 1 watt) or the E-130 (105 dB). They would make good PA system or guitar amp speakers, but are (IMO) poor choices for a home audio system. They require large ported cabinets, but will only produce bass down to about 50 Hz. They may be loud enough to remove all body hair and clothing on people 50 yards away, but they will lack bass. He seems determined to spend money on his "dream speakers" so I didn't try hard to talk him out of them. If he comes back to AH, maybe your experience with building the Tempests, and your obvious DIY chops can help change his mind.

That's funny. I have it saved too. I figured it wouldn't be long before we found an appropriate thread to unveil "The Beasts". lol

 

[shadyJ]

The OP of this thread had some ideas for his speakers that trouble me a bit. He wants to use enormous, expensive, and very sensitive 15" JBL woofers, the 2226H (97 dB at 1 watt) or the E-130 (105 dB). They would make good PA system or guitar amp speakers, but are (IMO) poor choices for a home audio system. They require large ported cabinets, but will only produce bass down to about 50 Hz. They may be loud enough to remove all body hair and clothing on people 50 yards away, but they will lack bass. He seems determined to spend money on his "dream speakers" so I didn't try hard to talk him out of them. If he comes back to AH, maybe your experience with building the Tempests, and your obvious DIY chops can help change his mind.

Swerd, first off, do not knock Domic's speakers- they are a labor of love!

Secondly, I think a reasonably high-fidelity speaker can be made with the drivers that the OP specified, but not the crossover he asked about. Those drivers are very good. He would just need to build a cabinet and crossover that integrates those drivers. Those are upper tier JBL pro drivers, the engineering that went into them is world class. I have heard home audio speakers that use pro sound drivers that had very good sound quality, and they weren't using drivers as good as those JBLs. Yes, he will not get deep bass from them, but that is what subwoofers are for. I wouldn't want to use a speaker made from those drivers without the assistance of a sub.

Also, what are the chances the music he is listening to actually uses frequencies lower than 50 Hz? I doubt that much of anything he listens to has content lower than 50 Hz, so those speakers will likely be just fine for him.

 

[Verdinut]

Swerd, first off, do not knock Domic's speakers- they are a labor of love!

Secondly, I think a reasonably high-fidelity speaker can be made with the drivers that the OP specified, but not the crossover he asked about. Those drivers are very good. He would just need to build a cabinet and crossover that integrates those drivers. Those are upper tier JBL pro drivers, the engineering that went into them is world class. I have heard home audio speakers that use pro sound drivers that had very good sound quality, and they weren't using drivers as good as those JBLs. Yes, he will not get deep bass from them, but that is what subwoofers are for. I wouldn't want to use a speaker made from those drivers without the assistance of a sub.

Also, what are the chances the music he is listening to actually uses frequencies lower than 50 Hz? I doubt that much of anything he listens to has content lower than 50 Hz, so those speakers will likely be just fine for him.

I checked with the BassBox Pro software for the JBL 2226J woofer.

Parameters indicate an Fs of 40 Hz with a Qts of 0.31. With those figures, to get a reasonably smooth bass response, he would have to build a ported cabinet of at least 7 cubic feet tuned at 45 Hz. With such design, he could get an F3 of around 41 Hz, which can satisfy a lot of music listeners.
That is the frequency of the low E on a double-bass.

The situation with those professional audio woofers is that they don't go down very low as compared to hi-fi speakers. Today's some 6.5 inch woofers will reach lower than this 15" woofer, and they will perform in quite smaller boxes.
I know quite a bit about pro audio speakers, as I have built and used Altec A7 component systems in my house and in my apartment afterwards.

 

[shadyJ]

Lol, how would you even fit an old Altec system in an apartment? I do have admiration for some of those high-powered vintage systems like the Altec Voice of the Theater speakers. I think it would be cool to watch a movie on such a system which would actually have been used with it, so some hollywood movie from the 1950's, like Hitchcock's Vertigo.

Yeah the 2226 does not dig deep, but that is the trade-off for the high sensitivity. It is a very low distortion driver in its intended frequency range. It is an extremely powerful driver. One guy I know who is an enthusiast for high power speakers said he considers it the best mid-bass driver he has ever used. Those who want deep bass will have to get a driver made for deep bass.

 

[Verdinut]

Lol, how would you even fit an old Altec system in an apartment? I do have admiration for some of those high-powered vintage systems like the Altec Voice of the Theater speakers. I think it would be cool to watch a movie on such a system which would actually have been used with it, so some hollywood movie from the 1950's, like Hitchcock's Vertigo.

Yeah the 2226 does not dig deep, but that is the trade-off for the high sensitivity. It is a very low distortion driver in its intended frequency range. It is an extremely powerful driver. One guy I know who is an enthusiast for high power speakers said he considers it the best mid-bass driver he has ever used. Those who want deep bass will have to get a driver made for deep bass.

They weren't installed in A7 cabinets but I used them in 7.6 cf enclosures and I am still using the same boxes to house my new front 3-way systems which consist of an Airborne Air Motion Ribbon tweeter, 2 Peerless mid-woofers and a Dayton RSS390HF-4 sub. The three front enclosures are identical with active bi-amplification crossing over at 200 Hz and a passive 2nd Order Linkwitz-Riley Low and 3rd Order Butterworth High x-over at 3600 Hz. The passive x-over is my own design using the X-Over Pro software for starters, adjustments using Dayton OmniMic V2 and appropriate voicing.

When I had my house, I did built a 16 cf ported cabinet to see how well a 416-8A woofer would perform. With that enclosure size, I had a solid response down to 29 Hz. That takes a lot of space if you are using two but it was a good experience.

However, the most practical way to get a decent low frequency response with that kind of woofer is to EQ it in a more acceptably sized ported 7.6 cf box with a 6th Order alignment, with which you would get an F3 of 28 Hz, if I remember well. I have the schematics to build a 6 dB boost EQ but I never tried it.

By the way, the Avatar picture on my profile shows the actual impedance and phase angle curves of an MTM speaker which I built several years ago. I don't think you would find many curves as good as those even among commercial speaker manufacturers.

This is what happens when we become passionate about something!

 

[shadyJ]

Your present system sounds like it could be quite good. The Dayton bass driver you mentioned is one I have long thought about fooling around with for some DIY projects. Very nice Le on that woofer, it should be very linear and have very low distortion. Do you have any pics of your system? What is the frequency response like?

 

[Verdinut]

Your present system sounds like it could be quite good. The Dayton bass driver you mentioned is one I have long thought about fooling around with for some DIY projects. Very nice Le on that woofer, it should be very linear and have very low distortion. Do you have any pics of your system? What is the frequency response like?

The cabinets are tuned to 16 Hz and, according to BassBox, I should be getting an F3 for each cabinet at 20 Hz. The frequency response on those is very smooth with an excellent stereo sound image with no hole in the center.
NOTE: The smaller 3-way speaker at the right is one from a pair of enclosures which I built a couple of years ago. I sold the pair to my nephew who hasn't picked them up yet. They use the Dayton RSS315HF-8 subs. One of my old friends, who is now retired from the Hi-Fi retail sales, considers these speakers as the best speakers along with the JBL S8R which he has ever listened to.

 

[shadyJ]

sorry, don't know what the max file size is. I use postimage.io for the pics that I post on these forums. Try Postimage.

 

[MrBoat]

I also notice a lot of people are using drivers like the PA460 and some of the Eminence etc woofers for more of a musical subwoofer. The Eminence driver used in the Tempest is typically not a low frequency driver yet they squeeze high 30's out of it.

Once we don't have to worry about HT so much, there are many more possibilities. If they could squeeze midbass out of those JBLs like they do with the Tempest, it would be a wonderful thing.

 

[shadyJ]

While you can squeeze deeper bass out of these type of drivers, but you should avoid doing so. High-pass filter all that stuff out. These drivers do not have the excursion to pull that type of bass off well. They run into heavy distortion, and it can also mess up the rest of the spectrum you want it to play in as well. This goes for the Tempest as well as the JBLs. Deep bass is not their wheelhouse.

 

[lovinthehd]

I also notice a lot of people are using drivers like the PA460 and some of the Eminence etc woofers for more of a musical subwoofer. The Eminence driver used in the Tempest is typically not a low frequency driver yet they squeeze high 30's out of it.

Once we don't have to worry about HT so much, there are many more possibilities. If they could squeeze midbass out of those JBLs like they do with the Tempest, it would be a wonderful thing.

It's not that they're "musical", they just don't go very low and that it's frequency range fits some people's definition of a musical range. Just a matter of choosing a driver appropriate to the goal....