Replacement drivers for JBL N26II

[DcibeL]

Hi,
I am interested in replacing the drivers in my JBL N26II speakers. These speakers don't sound horrible, but they lack "detail". I was thinking of building entirely new cabinets, with new speakers, but after dismantling the JBL speakers, I don't think I could do any better job at it with my limited amount of tools.

The cabinets are 3/4" mdf (well, at least the front of them are), and have some insulation material, a lovely 3000 Hz crossover, and a port that is flared at both ends. Exterior dimentions are 433 mm high, 229 mm wide, and 253 mm deep. Somewhere around 16 litres volume I think. It is hard to measure the port, because of the flared ends, but it looks to be about 40 mm diameter, and about 95 mm long.

I want to spend around $200 Canadian dollars on the replacement speakers. Looking at parts express my fist choice of speakers is the Peerless 850122 CSX 6 1/2" Woofer, and the Peerless 811815 1" Dome Tweeter. I am wondering if anyone has had any experience with these drivers, and how they will sound in the cabinet above. Would it be worth it for me to spend the extra money on the Peerless 850439 HDS 6 1/2" Woofer. Would you have any other recommendations for speakers besides the Peerless one's? I would like to keep both the woofers and the tweeters the same brand name.

Also, if anyone knows of a Web-site simmilar to Parts Express, where I can buy OEM drivers that is based in Canada, that would be mighty helpful.

Thank-you in advance for your help.

[Mark Hedges]

You might be better off reworking the crossover before you try replacing drivers. The drivers in these speakers are not that bad but the crossover components are dirt cheap.

I am just finishing up a project on my JBL S38's where I replaced all the electrolytic caps with Poly's, replaced the bypass caps with Audiocap Theta Film & foils, and replaced the cast sand resistors with Mills non-inductive resistors. I also installed a deflex pad behind the woofer & in the midrange enclosure.

I haven't listened to them a whole lot yet because I accidentally damaged one of the tweeters & am waiting for a replacement, but so far I am pleased with the results.

Mark

[DcibeL]

I don't know if this is the same as the speakers you have, but the crossover network on these speakers is built onto the wire terminal plate on the rear of the speaker. Would it be wise of me to simply replace these parts with more fancy parts, or would I be better off to print a new circuit. I guess what I am worried about is that a different part will be a different size, and won't fit onto this compact circuit. I do have access to a circuit printing machine at school, but I will have to wait about a month to use it, as everyone is cramming to get their technical thesis projects done right now.

From what I can see, the caps are a 4uF and an 8uF + or - 5% made by Elytone. The long inductor is an iron core, and the other is air core. I don't know what size, but a few simple calculations could find that out, since I do know the crossover frequency is 3kHz. Here's some pictures to give you an idea of this contraption.

[DcibeL]

I just had a look at Parts Express, would this give me the added quality that I need?

[ironwoods]

Hi, I have the all-weather version of the N26, and am very happy with the sound they provide out on the patio. You could also consider upgrading the x-over components as previously suggested.
If you can go a little higher, the Okara II($300+DIY cabinets)from NorthCreek music, seem to be a outstanding bookshelf. I'm looking forward to building them as my next project. You could sell the JBL's to help raise the needed funds.
A kit containing everything you need might suit you well, as a lack of tools can upset projects.
If this is your 1st project, I'd go with a proven design, as picking random drivers is a hit and mostly miss game. Although something like WinISD beta is free for download, and fun to play with. Throw the T/S parameters from your chosen drivers into it and voila
The BR-1's from PE are a great deal, but do need a fare amount of juice to power them.
Isn't there a partsconnexion or something, out of Canada?

[Mark Hedges]

That looks similar to the crossover in my speaker although mine was a 3 way bypassed design so it had many more components.

It should be pretty easy to remove the old components and install new ones. I used Mills resistors and Solen capacitors.

A quick search @ parts express gives:

Mills 2 Ohm resistor $3.50
Solen 3.9 µF cap $2.42
Solen 8.2 µF cap $3.91

Total cost ~ $10 per speaker.

If you want to get fancy you could try a better cap on the tweeter, especially since it isn't a bypassed design. The trouble is film & foil caps get big and expensive in a hurry.

You should be able to fit these parts on the boards ok - the resistor will be no trouble but the caps may be a tight fit. Still, I think you will be able to get them on there.

I would not use a finished parts express crossover because 1) you will get better parts if you do it yourself and more importantly 2) the crossover in your speaker is designed for those exact drivers. Who knows what the parts express crossover is designed for?

Mark

[DcibeL]

Thanks for your comments. I think I will order some parts and replace this crossover network, as it is a cheap and easy thing to do. Mark, how much of an improvement did you notice when modifying your JBL speakers? If they don't make much of a noticeable improvement for me, I think I will wait until my school semester is over, and I am back at work so I can afford to build something from scratch.

Thanks also for telling me about partsconnexion, they don't seem to sell speakers, but they do sell a whole lot of fancy components for building crossovers, etc.

[usekgb]

Here is a link to JBL N36II Technical Service Manual . It has all the info you should need about the speakers you have right now. In it you will find the x-over schematics and various other info on your speakers. I hope this helps.

Cheers,
Zach

[DcibeL]

That's lots of help! Thanks.

[Mark Hedges]

Originally posted by DcibeL
Mark, how much of an improvement did you notice when modifying your JBL speakers?

It is hard to say for sure yet because I dented in a tweeter on final reassembly and the replacement hasn't arrived yet (due on Monday).

For the small amount of listening I did do before I broke the tweeter I would say that it helped everything sound more real, particularly horns and wind instruments. I am using these speakers in my HT setup and I would say that movie sounds were more real as well.

I will give more detailed results after I have them working again and can listen to a broader range of material. Still, for $20 I don't see how you can go wrong.

Mark