I'm going to active EQ on the 3 fronts in our 5.1 system. The L & R are Klipschorns modified from 3 way to 2 way and the center is a Klipsch LaScala also changed to 2 way. The sides are Klipsch Heresies.
The high frequency horns I believe are properly rated at 8 ohms. The Klipsch Heresies are 8 ohm and will not be biamped.
I was about to buy four T4 amps for this but then remembered that the Klipschorn woofer is lower impedance. It is rated as 8 ohms but the impedance/frequency plots show it averaging 6 ohms with dips to 4 ohms.
So I'm wondering if I should use a T3 amp for the two Khorn woofers since it's a 4 ohm amp. But then it might suffer at the higher impedance points, as I'm concerned that the T4 might suffer at the lower impedance points.
The La Scala Impedance curves average about 7 ohms, but also with some 4 ohm dips
This seems a no win dilemma or am I just being too concerned and is this perhaps typical of a lot of speakers?
Thanks for any suggestions. Also might it be advisable to try to contact HiFiMeDIY directly? Or might he be responding here?
Rod
The high frequency horns I believe are properly rated at 8 ohms. The Klipsch Heresies are 8 ohm and will not be biamped.
I was about to buy four T4 amps for this but then remembered that the Klipschorn woofer is lower impedance. It is rated as 8 ohms but the impedance/frequency plots show it averaging 6 ohms with dips to 4 ohms.
So I'm wondering if I should use a T3 amp for the two Khorn woofers since it's a 4 ohm amp. But then it might suffer at the higher impedance points, as I'm concerned that the T4 might suffer at the lower impedance points.
The La Scala Impedance curves average about 7 ohms, but also with some 4 ohm dips
This seems a no win dilemma or am I just being too concerned and is this perhaps typical of a lot of speakers?
Thanks for any suggestions. Also might it be advisable to try to contact HiFiMeDIY directly? Or might he be responding here?
Rod
Thanks for the response Nigel.
I'm still really wondering if the T3 would not be a better solution for the Khorn woofers than the T4 I'll be using for others.
Thanks,
Rod
Of the two, I'd get T3. It has the current to double going from 150w at 8ohm to 300w into 4ohm. This means it can drive both loads without sweat.
OTOH the T4 is weak at 4ohm, actually falling from 180w to 90w at 4ohm
Hifimediy|Hifimediy T4 2 x 180W@8ohm amplifier
I'm using T3 monos and it's fab.
OTOH the T4 is weak at 4ohm, actually falling from 180w to 90w at 4ohm
Hifimediy|Hifimediy T4 2 x 180W@8ohm amplifier
I'm using T3 monos and it's fab.
Of the two, I'd get T3. It has the current to double going from 150w at 8ohm to 300w into 4ohm. This means it can drive both loads without sweat.
OTOH the T4 is weak at 4ohm, actually falling from 180w to 90w at 4ohm
Hifimediy|Hifimediy T4 2 x 180W@8ohm amplifier
I'm using T3 monos and it's fab.
Thanks Bernie. It really was looking like the T3 would be the better solution for the Khorn woofers.
Has anyone done a SQ comparison between a T3 & a T4?
I sure do wish we could get some distortion curves on these amp assemblies. Not just the chip manufacturer ones.
Rod
Distortion and noise performance would depend on your assembly too won't it? Prob why some kit suppliers don't provide measurements.
From hifimediy's site, T3 looks a no brainer choice to run with real world speaker loads.
Yes on distortion and noise measurements somewhat being a function of assembly. Actually that's a bit of a spooky part of this project, but will be the subject of a later thread.
Are you suggesting that the T3 may be the best choice for all our amps, the 8 ohm ones also? The small increase in power on the T4 @ 8 ohms is not an issue for us with our super efficient horns. We just want amps that put out a good dose of power so we have plenty of headroom, but are super clean.
Rod
If it's true that T4's power falls from 180w to 90w going 8 to 4 ohms, then one can draw the implications for oneself since speaker impedance generally fluctuate quite a lot over frequency. But this is at full power, and its behavior at lower power is not known, perhaps it's not as drastic. It would be interesting to plot the FR of the T4 at varying power levels and loads.
So now I'm thinking of ordering one T3 & one T4 initially instead of the 4 amps I need to end up with in the system.
Looks like they both use the same supply.
Will probably be quite awhile before I can spend a lot of time on the project but I plan to do some testing and listening comparisons. Should be interesting I'll post here afterwords.
Thanks for everybody's good input on this.
Rod
Rod,
I had the same dilemma with T3/T4 for my mixed sub setup and future use with active LCR setup. After pouring over the specs and doing costings i decided the basic T3 board was the better choice with the ability to better drive 8 or 4 ohm loads making the module more versatile over time with various drivers.
Have currently got two T3's running from SMPS's at 49V. One is driving a TH with a 15" 8 Ohm driver the other runs a pair of 18" ported cabinents in parrallel for 4 ohms.
Not having the T4 to compare all I can say is i consider the T3 to be a great little module that provides great bang for buck.
You can see the TH and bins in the attached photo.
The second photo shows one of the new fronts we have built that is currently passively crossed but we ultimately be driven by multiple T3's.
As you can see i haven't yet built a case around the amp modules.
Cheers
Phil
I had the same dilemma with T3/T4 for my mixed sub setup and future use with active LCR setup. After pouring over the specs and doing costings i decided the basic T3 board was the better choice with the ability to better drive 8 or 4 ohm loads making the module more versatile over time with various drivers.
Have currently got two T3's running from SMPS's at 49V. One is driving a TH with a 15" 8 Ohm driver the other runs a pair of 18" ported cabinents in parrallel for 4 ohms.
Not having the T4 to compare all I can say is i consider the T3 to be a great little module that provides great bang for buck.
You can see the TH and bins in the attached photo.
The second photo shows one of the new fronts we have built that is currently passively crossed but we ultimately be driven by multiple T3's.
As you can see i haven't yet built a case around the amp modules.
Cheers
Phil
Attachments
Thanks for the feedback Phil. Glad to know you are very satisfied with the T3. I have a hunch you are correct in your choice of the T3. But I'm still thinking of ordering 1 of each so I can do some comparisons.
Curious about your tapped horn. Is it your design? How low does it go and is the T3 enough for it? We have a Danley DTS-10 that we put together as a kit and am powering it with a Behringer EP-4000 (probably a real 900 watts). Love the tapped horn concept and it blends well with our modified Klipsch stuff. Horn all the way on the fronts makes me very happy!
Rod
Rod,
The TH is largely based on information in this thread http://www.diyaudio.com/forums/subwoofers/97674-collaborative-tapped-horn-project.html
it's 1800mm high x 600m deep and 450mm(odd) wide, not quite the straight up and down path, i introduced some extra folding at the top that obeys flare rates but adds a little extra length to extend the bottom end.
Hornresp was used and from memory we tuned to 22Hz with a response plot largely flat from 20Hz to 80Hz. I use 80Hz as my HT x-over point. A sine wave sweep sounds flat from 80 down to 20 with some further extension under 20 but not a lot.
Not having any even vaguely accurate measuring gear these days i have no direct evidence of actual SPL levels, Hornresp was show 130+ at 250W well inside the performance of the T3 and an easy match with the LCR set that model at 98db/1w
Audessy setup shows the subwoofer drive to be 2db lower then the LCR setup.
The driver used for Aussies is a 15"Etone Pro Driver (805 i think). Had to do full T/S measurements before trying to design the TH. That one and it's mate have done duty in W-Bins from my DJ days as well as serving as subwoofers in the back of one car
. I'd call them well run in.The 18" cabs start to roll off around 40Hz due to the cabinents being a little small for the drivers, but they seem to blend well with the TH.
For my setup the T3's provide more than enough grunt, no doubt assited by using high efficency Pro PA drivers.
Cheers
Phil
Rod,
The TH is largely based on information in this thread http://www.diyaudio.com/forums/subwoofers/97674-collaborative-tapped-horn-project.html
it's 1800mm high x 600m deep and 450mm(odd) wide, not quite the straight up and down path, i introduced some extra folding at the top that obeys flare rates but adds a little extra length to extend the bottom end.
Hornresp was used and from memory we tuned to 22Hz with a response plot largely flat from 20Hz to 80Hz. I use 80Hz as my HT x-over point. A sine wave sweep sounds flat from 80 down to 20 with some further extension under 20 but not a lot.
Not having any even vaguely accurate measuring gear these days i have no direct evidence of actual SPL levels, Hornresp was show 130+ at 250W well inside the performance of the T3 and an easy match with the LCR set that model at 98db/1w
Audessy setup shows the subwoofer drive to be 2db lower then the LCR setup.
The driver used for Aussies is a 15"Etone Pro Driver (805 i think). Had to do full T/S measurements before trying to design the TH. That one and it's mate have done duty in W-Bins from my DJ days as well as serving as subwoofers in the back of one car
The 18" cabs start to roll off around 40Hz due to the cabinents being a little small for the drivers, but they seem to blend well with the TH.
For my setup the T3's provide more than enough grunt, no doubt assited by using high efficency Pro PA drivers.
Cheers
Phil
Thanks Phil for explaining your TH & other speakers. Glanced at the thread on it - massive!
Don't want to take this thread too far OT so will end by saying that it's very impressive that the T3 will give you the kind of output you are getting down around 20 Hz.
Have fun,
Rod
Hi - Unfortunately the project is still sitting due to other priorities. I did buy a T4 but have note assembled it yet. Will post here when I do.
Cheers,
Rod
Thanks for a prompt response!
I'm actually listening to a T4 right now and would encourage you to assemble it. It's a good amp!
I'm planning to retire my HT amp (6.1) by adding two more Hifimediy amps. Having mixed impedance speakers with the center being 4 ohms and the rest 8 ohms I had the same dilemma as you. Decision: I will go for T3S for the center and T4 for the rest. Out of stock it says for both....but I can wait.
Cheers, Tore
I'm actually listening to a T4 right now and would encourage you to assemble it. It's a good amp!
I'm planning to retire my HT amp (6.1) by adding two more Hifimediy amps. Having mixed impedance speakers with the center being 4 ohms and the rest 8 ohms I had the same dilemma as you. Decision: I will go for T3S for the center and T4 for the rest. Out of stock it says for both....but I can wait.
Cheers, Tore
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