Let's talk home audio (again)

Oh... "Parts Express." Not "Part Sex Press." That's different.

The Pen Is Mightier!

Back from the dead!

I had picked up a pair of cheap bookshelf speakers for free (KLH 911b). I haven't measured it, but it's probably 1/2" MDF construction. If I wanted to upgrade them and have a small project, might it be as simple as picking up a good set of replacement drivers from parts express that are the same size and wiring them in? Or is it way more complicated than that?

I'm guessing the best I could sell them for would be $10, so I wouldn't mind spending a little money to improve them. Otherwise, I'd go out and pick up a used pair from the local hifi shop for $100 or so.

scardeal wrote: Back from the dead! If I wanted to upgrade them and have a small project, might it be as simple as picking up a good set of replacement drivers from parts express that are the same size and wiring them in? Or is it way more complicated than that?

It is and it isn't. The drivers work in tandem with each other via the crossover. It's critical that the crossovers are spec'd based on the individual drivers specs to work properly. OTOH, the crossover in a set of speakers like that is probably very basic, so replacing the original drivers with higher quality units with similar impedance will probably work fine.

A quick google search found this

http://www.diyaudio.com/forums/multi-way/79977-8-00-upgrade-old-pair-klh-911bs.html

The parts express forum is very good, and most of the people very helpful (unlike the one that I linked). You could ask there. If you need any help deciphering individual driver specs, just ask. Speaker building is one of my hobbies.

For drivers, I like to look at www.madisound.com. Lots of good info, plus they are just down the road from me. I never bought anything however.

I also go to diyaudioprojects.com for ideas and tech info. Good forum there, it's a little light on traffic but the regulars are usually quick to answer questions.

For the "good" system, find a vintage tube amp, or hybrid. I've been running an early 90's vintage Luxman, similar to the LV-103, and it produces great sound......much much better than the Yamaha surround sound receiver it replaced. Older tube amps are out there, and worth it, especially if you will be predominately playing vinyl.

For the "loud" system, I'd use an amp similar to my Yamaha receiver (around $1,000 new) and a set of Cerwin Vega, or old Kliptsch corner horns if you can find them. The C&V work great for music with heavy bass, while the old corner horns are basically indestructible!

The entry-level tube amps coming out of China are really no slouch either.... the Yaqin amps/integrateds sound quite nice.

scardeal wrote: If I wanted to upgrade them and have a small project, might it be as simple as picking up a good set of replacement drivers from parts express that are the same size and wiring them in? Or is it way more complicated than that?

It depends. Generally speaking, just tossing different drivers in a box won't work out well. If the box is too small, you end up with a big nasty peak in the mid-bass somewhere that can be pretty horrible sounding. If the box is too big, you end up with the bass rolling off pretty high making them sound "tinny".

I googled a pic of those speakers. Not sure if the woofer is any good, but that looks like one of those little mylar dome tweeters. Bang for buck, they usually perform very well. Generally speaking, making some improvements in the crossover is probably a better attack at a small project like that than buying drivers. Maybe try replacing the caps with some Dayton film caps from parts express.

The crossovers in speakers like that are often simple cap and coil filters. Nothing wrong with that if the drivers are designed to work with it and have roll off that compliments the simple electronics. But if you wanted to try something more ambitious, you might try designing a second order crossover for them. Probably cost less than new drivers and deliver a lot more improvement.

Just one more note - it can be remarkable how good "cheap" drivers can sound if they're in a well-designed system. If the cabinet is appropriate for the woofer and the crossover is well designed, inexpensive drivers can be made to sound good. Conversely, really good drivers in a poorly designed system can sound terrible. .

I would tend to disagree with most of what you said. Mylar tweeters are junk, and should be the first thing to go. Replacing the caps for better ones in a speaker like this would be a waste of time, energy, and money. Crossover building without experience and/or measuring equipment would be a similar waste. Do the tweeters first (there are some excellent budget tweeters available that should be an easy drop in), then start looking at woofer choices if you're not happy with what's there.

Zomby Woof wrote: I would tend to disagree with most of what you said. Mylar tweeters are junk, and should be the first thing to go. Replacing the caps for better ones in a speaker like this would be a waste of time, energy, and money. Crossover building without experience and/or measuring equipment would be a similar waste. Do the tweeters first (there are some excellent budget tweeters available that should be an easy drop in), then start looking at woofer choices if you're not happy with what's there.

Well, you know, that's just, like, your opinion man.

No worries. You can disagree with me. But I am speaking from experience and stand by what I said. Replacing a driver without changing anything else in the system is unlikely to result in anything that would perform better than the original. I’ve restored dozes of speakers and I’ve designed and built more than a few pairs. Replacing drivers is a "last resort" measure.

As for Mylar tweeters, read what I said again. For the money, which is next to nothing, they perform surprisingly well. Some great sounding speakers use Mylar tweeters. I used to own some DCM Timeframe 400s that were really nice speakers. Boston Acoustics used a Mylar tweeter in the A40 and I still consider that speaker a giant killer. Boston still uses Mylar in a lot of their in wall home theater speakers to good effect. I didn't say they were the best tweeters ever made, only that for the money, they perform well. They also tend to cross over very high, so the likelihood of a vast improvement from finding a different tweeter is small, even assuming you correctly found something with an appropriate efficiency and impedance.

Check out the very interesting review of the Audax TW010F1 Mylar dome tweeter on Madisound. It costs $5.75. Cheap, but not junk by a long shot.

http://www.madisoundspeakerstore.com/audax-soft-dome-tweeters/audax-tw010f1-10-mm-polymer-dome-tweeter/

Mylar was good enough for John Dunlavy.

I've always wanted to build a set of curvy changs

fast_eddie_72 wrote: Well, you know, that's just, like, your opinion man. No worries. You can disagree with me. But I am speaking from experience and stand by what I said. Replacing a driver without changing anything else in the system is unlikely to result in anything that would perform better than the original. I’ve restored dozes of speakers and I’ve designed and built more than a few pairs. Replacing drivers is a "last resort" measure. As for Mylar tweeters, read what I said again. For the money, which is next to nothing, they perform surprisingly well. Some great sounding speakers use Mylar tweeters. I used to own some DCM Timeframe 400s that were really nice speakers. Boston Acoustics used a Mylar tweeter in the A40 and I still consider that speaker a giant killer. Boston still uses Mylar in a lot of their in wall home theater speakers to good effect. I didn't say they were the best tweeters ever made, only that for the money, they perform well. They also tend to cross over very high, so the likelihood of a vast improvement from finding a different tweeter is small, even assuming you correctly found something with an appropriate efficiency and impedance. Check out the very interesting review of the Audax TW010F1 Mylar dome tweeter on Madisound. It costs $5.75. Cheap, but not junk by a long shot. http://www.madisoundspeakerstore.com/audax-soft-dome-tweeters/audax-tw010f1-10-mm-polymer-dome-tweeter/ Mylar was good enough for John Dunlavy.

Seriously, those Audax tweeters are junk. They were an ok cheap tweeter when they came out, but are LONG past being an acceptable choice with what's available now in a similar price range. Likewise, those KLH speaker were really cheap when new, and since then, some very high quality parts have become available to the hobbiest at reasonable prices. I've designed and built hundreds of speakers since I started into the hobby in the 70's, but don't consider myself to be an expert. I do, however, consider some of the regular posters on the PE forum to be, and that's why I referred him there.

If you are a hobbiest, you owe it to yourself to check out some of the Dayton, Tangband, and Hivi stuff to see what reasonably priced, high quality, modern drivers are.

As an alternative, would I do better to play with this?

http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-301