Compression Horn Driver in a Bookshelf???

[adwilk]

I'm wanting to start a new project, a midsize bookshelf, but i'm looking for something a little different. I was in a local stereo shop and listened to the Klipsch Reference series again, and i'm convinced i need a tactrix horn in my new monitor. Good Idea, Bad Idea? I'm really wanting something dynamic for movies and some music. Mostly movies though.. Anybody tried something like this? What did you use? You also might try to talk me out of this, i'm very skeptical... thanks a bunch

 

[adwilk]

Is this just a really bad idea??? I dont see why it wouldnt work.. I just plan on building a really good cabinet and maybe even the integral horn in the baffle... i payed attention in woodshop. I'm just not sure what to use for the driver. I'll be really careful with the electronics and bi-amp to tone down the high end.. that was my complaint with the klipsch... any comments or suggestions???

 

[j_garcia]

You paid attention in wood shop, but I don't think you're going to be hand carving a waveguide anytime soon (maybe you are?). You say you're convinced you want to do horns, then you say in the next post you didn't like the highs on the Klipsch. Yes you can use the crossover to tame it some, but horn loaded drivers are generally going to give you a bright presentation by design, so if that is not what you liked, maybe you'll need to listen to some more speakers? If you want crisp, but not bright, you may simply want to look at some metal dome tweeters. Have you built a speaker before?

I don't get you with the biamping? That isn't going to tame the tweeter. What's the budget for the design?

 

[adwilk]

Actually i have built some speakers before, a sub, some bookshelfs for the office and some towers for the house... My complaint with the Klipsch was the highend in the RF-7 Tower used with a denon 7.1 HT Receiver... way too bright listening to rock music and peircing when russell crowe draws his sword at reference level. Other than at those moments, i absolutely love it... more than that, i love the effeciency and imaging that the design created. So, i thought, i can re-create that.. yes, if necessary, i will handmake the baffle, not carved of one piece though.. (did fall asleep in class once or twice).. but will be of wood and good design.

As far as biamping goes, I'll just adjust the gain to a lower level on the horn than the woofer (have heard this done with the RF-5.. AMAZING) and there ya go... Just wanted to know what makes the klipsch so effecient and what compression driver to use for a monitor setup... i'll build my crossover depending on what final woofer selection i make... budget... no issue. i just want to try something new.

 

[j_garcia]

The waveguide of a horn loaded speaker is very specifically designed (parabolic) for proper dispersion. I'd stick with buying one rather than trying to make one.

If you're designing the speaker, there's no reason not to design it to sound the way you like from the beginning. Using electronics to tame aspects you don't like about a speaker you designed is like buying a new car in a color you don't like and then having it painted...

Starting from scratch and with biamping a definite possibility, you might as well just skip the passive x-over altogether and just use an active (electronic) x-over prior to the amplification stage. That will allow you the ability to make adjustments to achive the desired sound and it will also allow the amplification to be put to optimum use.

 

[adwilk]

After a couple hours in the shop last night, its very evident that i will be buying the waveguide... I've started the construction of the cabinets and i think i will eliminate a passive xover. I had been thinking about that... my only concern is that most the drivers for a horn loaded application focus on really high output and i dont want this speaker to sound like a PA system. I'll get these things built and will definitely be back for some direction. Any reccomendations on a driver to use?

 

[Swerd]

Do not skip the crossover!

After a couple hours in the shop last night, its very evident that i will be buying the waveguide... I've started the construction of the cabinets and i think i will eliminate a passive xover. I had been thinking about that... my only concern is that most the drivers for a horn loaded application focus on really high output and i dont want this speaker to sound like a PA system. I'll get these things built and will definitely be back for some direction. Any reccomendations on a driver to use?

Do not eliminate the crossover ! Your woofer will be driven at higher frequencies than it was intended for. It will probably sound awful because you will hear the high frequency break up noise. Any speaker that uses more than one driver should have a crossover that limits the woofer output to a range where it is relatively flat, and limits the tweeter output to a range where it will not be destroyed by frequencies too low for it to handle. It makes no difference whether the crossover is active or passive, or whether the tweeter is a horn, dome, or cone.

Yes, most horn-loaded tweeters have much higher output than hifi woofers and are meant for use in PA systems, not hifi speakers. The woofers used in PA speakers also have much higher output, again at the expense of high quality sound. One way to deal with high tweeter output is to add resistors to the tweeter section of the crossover, in a circuit called an L-pad, that lower the output of the tweeter to the level of the woofer. You can even buy variable L-pads that include an adjustable tweeter volume knob that you mount on the speaker cabinet.

If you didn't like the sound of Klipsch speakers, you really should stay away from horn-loaded tweeters in general. Many people find they are too bright sounding. They may have a big wow factor when you first hear them, but with time you experience "listener fatigue" and grow to dislike them.

It seems that you are interested in buiding your own speakers. I'm all for that! You might try reading this article http://www.speakerbuilder.net/web_files/Articles/xover article/xpointmain.htm that discusses some general principles of selecting woofers, tweeters, and a suitable crossover point.

You might like reading several of the other articles at this web site http://www.speakerbuilder.net/web_files/default.htm. I found them very useful when I was a DIY newbie.

 

[adwilk]

i appreciate the info and links, i am planning on using an active crossover prior to amplification, like garcia said... I dont dislike the Klipschs, but i want to refine them just a bit... I'll keep everybody posted.. the more i read and i think the more i experiment with drivers, the more i'll be able to accomlplish what i'm after... maybe not.

 

[j_garcia]

Do not eliminate the crossover ! Your woofer will be driven at higher frequencies than it was intended for. It will probably sound awful because you will hear the high frequency break up noise. Any speaker that uses more than one driver should have a crossover that limits the woofer output to a range where it is relatively flat, and limits the tweeter output to a range where it will not be destroyed by frequencies too low for it to handle. It makes no difference whether the crossover is active or passive, or whether the tweeter is a horn, dome, or cone.

An active crossover prior to the amplification stage removes the need for a passive crossover, since the crossover function has taken place before the signal is even amplified. The drivers will still receive a frequency band that is hopefully tailored to the driver in the same way a passive network would be, so there is no danger of the driver operating outside of it's range. In essence, it is MORE efficient than a passive network because amplifier power is not wasted on amplifying the full range signal.

One way to deal with high tweeter output is to add resistors to the tweeter section of the crossover, in a circuit called an L-pad, that lower the output of the tweeter to the level of the woofer. You can even buy variable L-pads that include an adjustable tweeter volume knob that you mount on the speaker cabinet.

L-pad in the x-over is adding another component. While it does allow you some adjustment, it also affects the crossover as a whole and has the potential to slightly degrade the sound.

 

[adwilk]

okay, speakers pretty well complete... i havent actually mounted the baffles yet as i'm still playing with woofer size... I have two pair, i built one with passives and one with no internal electronics. The ones using the active crossover and bi-amped actually sound like dog$***. I cant make them sound good. They are just too much... I think i would have to drop a lot of loot on a better crossover, eq and.. well i'm really surprised at the turnout. The ones with the passive consists of a 4th order xover @the woofer and a 2nd order for the horn. xdover @ about 3100... sounds pretty da** good watching movies, a little overwhelming with some rock music... overall, i'm pleased with what i learned and really apprceciate the quality of the Klipsch design.. These stupid things probably have a sensitivity of just above a hundred.. very very effecient. I'll post complete design specs, xover schematics, and of course pics in the next couple of days...

 

[j_garcia]

Kind of surprised too, but it most likely has to do with the x-over. Definitely post your results up for the passive one.