klipsch rf5's rebuild.

[photographer86]

Okay, I have some klipsch rf5's. I know the speaker cabinet is designed the way it is. However I want to build my own to the same design and use it as a center channel. I have 2 extra pair from a music room I know long use and have 2 pair I am using in the theater. I want everything to match. I know I know probably over kill but my question is if I were to build my own cabinet for them and they're maybe 38 inches tall now but made a smaller cabinet for a center speaker..... I know I might loose a little bottom end in bass but really would it be notifiable. Is it worth the experiment taking ones guts and putting in different size cabinet. Can some audioholics tell me if I made the cabinet maybe only 25 inches wide if I would really notice a difference? If im crazy tell me and I won't do it lol. Thanks guys.

 

[Grant.M]

You’re right, you’ll probably lose some bass, but you may change the frequency response curve a bit due to the change in the cabinet volume as well. And even small changes in enclosure size can change tuning frequency and create some unevenness in the response. If you do make it smaller then I would try a sealed enclosure, not ported as you don’t have the needed parameters (unless you can figure out which drivers are used and find them) to find the proper enclosure volume and port volume for tuning the low end frequency response. You should have the driver parameters for building a sealed enclosure as well, however I assume it will be more forgiving to go that route and the response a bit smoother. I’d recommend using acousta stuff/poly fill to mimic a larger enclosure (to an extent) and you might be able to tune it a bit that way as well. A center channel doesn’t have to dig as low, especially if it’s set to small and crossed over at 80Hz anyway (from your AVR settings). I say go for it! Worst case scenario you don’t like it, and you come away with a learning experience and a nice cabinet. Also if it doesn’t work out the way you’d like, you could try adding an adjustable port at that point and try changing the port length and see if you could get sound you like. You can also try ordering some drivers off somewhere like Parts Express and try that out if all is said and done and you still aren’t satisfied. You’ll get all the necessary driver parameters to get everything right (or closer to it anyway lol) that way! And remember, it doesn’t need to be perfect as long as you like it.
Also when building the cabinet brace it heavily, design it so it doesn’t have too many parallel sides, and try to make the front baffle nice and thick (~1.75”+),walls should preferably be at least .75” as well. This will reduce standing waves and cabinet resonance.

I attached the cabinet dimensions below.

Good luck, and have fun!

 

[photographer86]

You’re right, you’ll probably lose some bass, but you may change the frequency response curve a bit due to the change in the cabinet volume as well. And even small changes in enclosure size can change tuning frequency and create some unevenness in the response. If you do make it smaller then I would try a sealed enclosure, not ported as you don’t have the needed parameters (unless you can figure out which drivers are used and find them) to find the proper enclosure volume and port volume for tuning the low end frequency response. You should have the driver parameters for building a sealed enclosure as well, however I assume it will be more forgiving to go that route and the response a bit smoother. I’d recommend using acousta stuff/poly fill to mimic a larger enclosure (to an extent) and you might be able to tune it a bit that way as well. A center channel doesn’t have to dig as low, especially if it’s set to small and crossed over at 80Hz anyway (from your AVR settings). I say go for it! Worst case scenario you don’t like it, and you come away with a learning experience and a nice cabinet. Also if it doesn’t work out the way you’d like, you could try adding an adjustable port at that point and try changing the port length and see if you could get sound you like. You can also try ordering some drivers off somewhere like Parts Express and try that out if all is said and done and you still aren’t satisfied. You’ll get all the necessary driver parameters to get everything right (or closer to it anyway lol) that way! And remember, it doesn’t need to be perfect as long as you like it.
Also when building the cabinet brace it heavily, design it so it doesn’t have too many parallel sides, and try to make the front baffle nice and thick (~1.75”+),walls should preferably be at least .75” as well. This will reduce standing waves and cabinet resonance.

I attached the cabinet dimensions below.

Good luck, and have fun!

Thank you very much Grant. You're thinking the same I am! Might be a fun little project and I know all the stuff the stuff you're talking about. Ya the only cost I would have is cabinet material and dampening material. I have the klipsch cross over and drivers and horn tweeter. Just want to put it on its side. Just didn't need the whole tower it self lol. I will probably do it for the learning experience for fun. I do follow you on if it sounds good to me yup I understand that but like knowing that everything else matches as far as design and such. Thanks for the info and reply. Answer I was looking for.

Also grant, I have REW room eq wizard and a calibrated umm6-1 microphone. What else beside calibrating my home theater system to the 75db standard could I do with this mic and software for speaker building. Any building sites I can learn stuff on and read about. thanks.

 

[Grant.M]

Thank you very much Grant. You're thinking the same I am! Might be a fun little project and I know all the stuff the stuff you're talking about. Ya the only cost I would have is cabinet material and dampening material. I have the klipsch cross over and drivers and horn tweeter. Just want to put it on its side. Just didn't need the whole tower it self lol. I will probably do it for the learning experience for fun. I do follow you on if it sounds good to me yup I understand that but like knowing that everything else matches as far as design and such. Thanks for the info and reply. Answer I was looking for.

Awesome! I feel you, I like to have everything timber matched as well. Keep us updated on the build, I’d love to see the finished product.

 

[photographer86]

Will do. I have used all matching speakers before and the sound you get really sounded more equal vs using even though a manufacturer said its a matching center which im sure it is but using exactly the same was like wow! So even and right. Yes were are probably over kill but seems to really make a difference. Thanks will update you.

 

[Pogre]

Definitely not my area of expertise, but projects like this don't usually turn out positively. Changing the enclosure like that I'd think you would have to design a different crossover... for starters.

 

[Grant.M]

Definitely not my area of expertise, but projects like this don't usually turn out positively. Changing the enclosure like that I'd think you would have to design a different crossover... for starters.

For getting the best performance possible then an adjustment to the crossover might be necessary. I could be wrong, but since he’s not trying to use different drivers then the ones the xo was designed for it shouldn’t be too bad. Bass will probably be the biggest issue in the frequency response curve by changing the enclosure volume.

 

[photographer86]

For getting the best performance possible then an adjustment to the crossover might be necessary. I could be wrong, but since he’s not trying to use different drivers then the ones the xo was designed for it shouldn’t be too bad. Bass will probably be the biggest issue in the frequency response curve by changing the enclosure volume.

You all valid points here guys for sure. That's why I asked. Is it gonna be so bad that it's not worth the change. Maybe Ill just build a new box to same size and Just put mid tweeter mid like a center channel. Yup all the same guts will be used. Just making it horizontal instead of vertical. Though wanted to go a bit smaller on cabinet size just to fit better above or below tv.

 

[ryanosaur]

I've been studying speaker design the last few months and @Pogre is right.
You cannot make changes like that without risking a great deal.
The cabinet is tuned to the driver in many ways. First as a resonator... but if you change the cabinet resonance, you could incur significant and irreparable damage to the driver. The port is also very specifically designed to couple with the cabinet size and driver parameters to increase bass performance at a specific point... this will also affect driver impedance, and if not tuned properly will likely affect sound quality in a very negative way. At that point you do get into the crossover, which is specifically designed for those drivers, on that specific baffle, in that specific volume. Slight changes can take a passable XO and make it worthless.

I highly encourage any and all to read the speaker design books. They are very informative and will help you understand just exactly how complex a system a speaker is!

Start with the Weems book, then the Alden. I also like Dickason's LDCv7, but it is more advanced.

 

[ryanosaur]

You all valid points here guys for sure. That's why I asked. Is it gonna be so bad that it's not worth the change. Maybe Ill just build a new box to same size and Just put mid tweeter mid like a center channel. Yup all the same guts will be used. Just making it horizontal instead of vertical. Though wanted to go a bit smaller on cabinet size just to fit better above or below tv.

If you want the best sound possible, use matching towers. Make it fit.
You cannot turn most vertical speakers sideways without incurring significant distortion through diffraction.
If you cannot use the same tower, use a smaller sibling tower or bookshelf. If you have to use a specifically designed center speaker, then use one that is designed for that purpose: 2-way mtm or wtw designs, or 3-way w-t/m-w type designs that have well built and tested XOs (crossovers) for the purpose at hand.
I fully support experimentation, but some things are known to not work.

 

[photographer86]

If you want the best sound possible, use matching towers. Make it fit.
You cannot turn most vertical speakers sideways without incurring significant distortion through diffraction.
If you cannot use the same tower, use a smaller sibling tower or bookshelf. If you have to use a specifically designed center speaker, then use one that is designed for that purpose: 2-way mtm or wtw designs, or 3-way w-t/m-w type designs that have well built and tested XOs (crossovers) for the purpose at hand.
I fully support experimentation, but some things are known to not work.

Thanks ryan. Gonna look into some of those books at library. Also so if I made a cabinet all the same size of the tower. Took the componets out of the one i want to convert to a center as in crossover and drivers all i have to do is rotate the horn tweeter cause its vertical now. So it would be a center channel. ill have some crazy impact? Even if its the same crossover. Let me draw a pic of what I want to do. ill post in a minute from phone.

 

[photographer86]

 

[photographer86]

Okay so I want to take same drivers and guts but make it like that to the design on the right cause I have a extra rf5, 2 actually not using. But if i make the cabinet say only 18 inches smaller would it have a pretty impact?

 

[ryanosaur]

Thanks ryan. Gonna look into some of those books at library. Also so if I made a cabinet all the same size of the tower. Took the componets out of the one i want to convert to a center as in crossover and drivers all i have to do is rotate the horn tweeter cause its vertical now. So it would be a center channel. ill have some crazy impact? Even if its the same crossover. Let me draw a pic of what I want to do. ill post in a minute from phone.

It will most likely have a significant impact.

I'm very excited to begin my first build soon... going to do a second pair of speakers to use for Atmos, and upgrade the first... based on an existing design by the person who did all my other speakers. I want my first build to be successful!

I've also been told, after doing a kit or some such build, to try you hand at a subwoofer. It's easier than other speakers to assemble and tune, and less expensive to do.

 

[photographer86]

Very good then. Okay I might try and build for fun myself and take a measure with calibrated mic and REW just to see where they measure. Though I dont have a chamber to speakers in I would do my best to measure only the speaker. Okay thanks for all the comments and my awesome drawing lol. Update you guys if I build this weekend.

 

[ryanosaur]

Okay so I want to take same drivers and guts but make it like that to the design on the right cause I have a extra rf5, 2 actually not using. But if i make the cabinet say only 18 inches smaller would it have a pretty impact?

You will not be able to use the same XO, and the size difference will have a big impact. Cabinet resonance, driver stability, port tuning all have to be accounted for, and then you will need to redisign the XO from the start.

Other than the cost of the cabinet and your time... I would still not advise doing this.

You would be better off selling the speakers and investing in a proper center.

 

[photographer86]

Want to see your build also!!!

 

[photographer86]

You will not be able to use the same XO, and the size difference will have a big impact. Cabinet resonance, driver stability, port tuning all have to be accounted for, and then you will need to redisign the XO from the start.

Other than the cost of the cabinet and your time... I would still not advise doing this.

You would be better off selling the speakers and investing in a proper center.

Very good then. Ill see what matching center went with the RF5's back then and see if I can find a used one.

 

[photographer86]

http://images.klipsch.com/RC7_635042119071830000.pdf

thats the matching center and I see its has 2 cross over points.

 

[Grant.M]

I've been studying speaker design the last few months and @Pogre is right.
You cannot make changes like that without risking a great deal.
The cabinet is tuned to the driver in many ways. First as a resonator... but if you change the cabinet resonance, you could incur significant and irreparable damage to the driver. The port is also very specifically designed to couple with the cabinet size and driver parameters to increase bass performance at a specific point... this will also affect driver impedance, and if not tuned properly will likely affect sound quality in a very negative way. At that point you do get into the crossover, which is specifically designed for those drivers, on that specific baffle, in that specific volume. Slight changes can take a passable XO and make it worthless.

I highly encourage any and all to read the speaker design books. They are very informative and will help you understand just exactly how complex a system a speaker is!

Start with the Weems book, then the Alden. I also like Dickason's LDCv7, but it is more advanced.

I’ve got a lot more learning to do about this, I’ll check those books out and give them a read. Thanks Ryan!