Which driver do you think would be appropriate for a floor to ceiling bass array? I'm crossing over to a rd75 ribbon @ 500Hz active, slope TBA.
I'm concerned about vocal clarity near the crossover point using the 10" foster, even though the modeled freq-resp curve seems like it's still relatively flat at that point. The 8" peerless clone seems like it has a better chance at combining smoothly with the ribbon. The only alternative I see is NPT-11-077-1 pulled from the center channel. If anyone has experience with these let me know how it's gone. Thanks!
I'm concerned about vocal clarity near the crossover point using the 10" foster, even though the modeled freq-resp curve seems like it's still relatively flat at that point. The 8" peerless clone seems like it has a better chance at combining smoothly with the ribbon. The only alternative I see is NPT-11-077-1 pulled from the center channel. If anyone has experience with these let me know how it's gone. Thanks!
I was just over there a few days ago and apparently there's plenty, and even more of the plate amps.
For Burning Amp participants, Jack is bringing some down to the meet along with a Klippel for measurement- anyone who buys drivers gets them measured individually on the spot. Disclaimer: no financial interest here, but my garage lab is now stuffed to the rafters with NHT gear.
For Burning Amp participants, Jack is bringing some down to the meet along with a Klippel for measurement- anyone who buys drivers gets them measured individually on the spot. Disclaimer: no financial interest here, but my garage lab is now stuffed to the rafters with NHT gear.
I wouldn't use the 10" Foster driver up that high. The distortion from the inductance is going to be fairly high compared to the ribbon drivers.
The 8" Peerless or clone would work pretty well. The 079 will work well, but require more drivers. The 081 will give you the lowest distortion because of the shorting rings, but will require the greatest number of drivers.
I've updated the spreadsheet on the sale site.
We're planning on bringing our Klippel system and an AP to Burning Amp in SF, so we can do linear and nonlinear driver measurements for people.
The 8" Peerless or clone would work pretty well. The 079 will work well, but require more drivers. The 081 will give you the lowest distortion because of the shorting rings, but will require the greatest number of drivers.
I've updated the spreadsheet on the sale site.
We're planning on bringing our Klippel system and an AP to Burning Amp in SF, so we can do linear and nonlinear driver measurements for people.
NPT-11-075-2 vs. NPT-11-083-2
Jack,
I'm already satisfied with a plan I have to use a 2.1 approach with some Seas drivers (ER18RNX H1456 and 27TDFC H1189) in a two-way loudspeaker and a single NHT 1259/SA-3 amplifier that I already own, but want to explore a three-way version of the system using two separate subwoofer enclosures with active crossovers and 6-channel amplification.
I've read your earlier post #13 in this thread about the high end behavior of the NPT-11-075-2 Foster driver. So, this is about the NPT-11-075-2 vs. NPT-11-083-2 10" Foster drivers. Oh, since the difference is $40 for 4 drivers, price isn't a consideration between the two.
I've modeled both drivers used as two in parallel, 80 liters sealed enclosure, and have also modeled the Linkwitz Transform needed for both and they are very close. Unless I've missed something I don't see any issues that would prevent using either driver.
So, In your opinion which of the two drivers would be best to utilize in the following context?
Thanks, Mike
Jack,
I'm already satisfied with a plan I have to use a 2.1 approach with some Seas drivers (ER18RNX H1456 and 27TDFC H1189) in a two-way loudspeaker and a single NHT 1259/SA-3 amplifier that I already own, but want to explore a three-way version of the system using two separate subwoofer enclosures with active crossovers and 6-channel amplification.
I've read your earlier post #13 in this thread about the high end behavior of the NPT-11-075-2 Foster driver. So, this is about the NPT-11-075-2 vs. NPT-11-083-2 10" Foster drivers. Oh, since the difference is $40 for 4 drivers, price isn't a consideration between the two.
I've modeled both drivers used as two in parallel, 80 liters sealed enclosure, and have also modeled the Linkwitz Transform needed for both and they are very close. Unless I've missed something I don't see any issues that would prevent using either driver.
So, In your opinion which of the two drivers would be best to utilize in the following context?
- My main objective is lowest overall distortion of all types.
- Music only system with moderate playback levels. Quality is FAR more important than quantity.
- Each subwoofer would be two of the Foster 10s in appx. 80 liters sealed.
- LR4 low-pass active filter for the Foster woofers with the crossover point somewhere between 80-90 Hz.
- A Linkwitz Transform (or other slight EQ) to shape the bottom-end response of the Foster woofers.
Thanks, Mike
Mike,
It doesn't really make any difference which driver you use, the 075 or 083. They are nominally the exact same driver except for the frame materials.
Obviously the T/S parameters for the two drivers posted are not identical. That is because the data is pulled from two different samples with no averaging of multiple units. All of the difference between these two samples is because of the difference in Cms. Once you install either driver in a relatively small sealed enclosure, you will find that the frequency responses will be nearly identical. Compare the data from the Klippel analysis's. There it is more obvious how the drivers are the same.
The 083 will have slightly higher power handling due to the cast aluminum frame having lower thermal resistance and more thermal mass than the 075 driver, but the difference won't be much.
It doesn't really make any difference which driver you use, the 075 or 083. They are nominally the exact same driver except for the frame materials.
Obviously the T/S parameters for the two drivers posted are not identical. That is because the data is pulled from two different samples with no averaging of multiple units. All of the difference between these two samples is because of the difference in Cms. Once you install either driver in a relatively small sealed enclosure, you will find that the frequency responses will be nearly identical. Compare the data from the Klippel analysis's. There it is more obvious how the drivers are the same.
The 083 will have slightly higher power handling due to the cast aluminum frame having lower thermal resistance and more thermal mass than the 075 driver, but the difference won't be much.
Jack will be at the Burning Amp show in San Francisco on Oct 21st.
He will have lots and lots of drivers for sale and will demonstrate how to measure drivers to get their parameters.
AND!!! anyone who buys a driver gets the parameters custom measured for that particular piece!!!
Quite a service I think..
He will have lots and lots of drivers for sale and will demonstrate how to measure drivers to get their parameters.
AND!!! anyone who buys a driver gets the parameters custom measured for that particular piece!!!
Quite a service I think..
Jack Hidley said:We'll probably bring half of the inventory listed on the website, plus some more top secret stuff (other drivers, used test equipment, etc). But you will have to show up in SF to find out what they are! Remember to max out your ATM cash on Friday and Saturday nights
I'm on the wrong side of the country.
I dare say I'd like some of that stuff, though. Being a student = being broke.
Thanks for the speakers...
Hi Jack:
Just a note to thank you for the speaker cabinets and drivers you were kind enough to give me at the Burning Amp on Sunday.
They will be perfect for my desk / home studio setup once I get them sorted.
Can you please point me to some information about the drivers (they seem to be labelled 8ns 87-11,24 and made in Denmark for the woofer, and 1-11-020 for the tweeter). Neither seem to be in the spreadsheet you published.
You also mentioned that it would be possible to download a crossover design. Could you please point me in the right direction? Any information about the original product would be interesting and useful.
Thanks again,
tim
Hi Jack:
Just a note to thank you for the speaker cabinets and drivers you were kind enough to give me at the Burning Amp on Sunday.
They will be perfect for my desk / home studio setup once I get them sorted.
Can you please point me to some information about the drivers (they seem to be labelled 8ns 87-11,24 and made in Denmark for the woofer, and 1-11-020 for the tweeter). Neither seem to be in the spreadsheet you published.
You also mentioned that it would be possible to download a crossover design. Could you please point me in the right direction? Any information about the original product would be interesting and useful.
Thanks again,
tim
Tim,
Just PM me your e-mail address and I'll send the schematic. The woofer is a Peerless TP165R. Quite an old model.
The tweeters we gave you are about 1-2dB less sensitive than the tweeter designed for the product. You will just need to adjust the series resistor in the HP section of the crossover and rescale the L and C values.
Just PM me your e-mail address and I'll send the schematic. The woofer is a Peerless TP165R. Quite an old model.
The tweeters we gave you are about 1-2dB less sensitive than the tweeter designed for the product. You will just need to adjust the series resistor in the HP section of the crossover and rescale the L and C values.
It will take me a couple of days to accurately adjust the inventory numbers. Here is brief rundown.
077 drivers. All gone.
082 drivers. All gone.
Terminal plate. All gone.
250W amplifier modules and power supplies. All scrapped.
All of the above adjustments are currently reflected in the spreadsheet online. Beyond that:
079 drivers. Running low. Maybe 15 pieces.
All other drivers. Quite a lot left.
077 drivers. All gone.
082 drivers. All gone.
Terminal plate. All gone.
250W amplifier modules and power supplies. All scrapped.
All of the above adjustments are currently reflected in the spreadsheet online. Beyond that:
079 drivers. Running low. Maybe 15 pieces.
All other drivers. Quite a lot left.