Robbie010

Thanks to all for the responses. Can I ask what subs you are using @baron167?

Now that I have gone active with my clone La Scala, overall sensitivity and crossovers are no longer a concern and a world of driver options has opened up to me. I have already installed Crites CT120 Tweeters, which has given the top end a real boost and clarity. This has got me thinking..... is there a drop-in 15” woofer driver on the market that will replace the stock K33’s and get me closer to 20Hz without needing physical alterations to the cabs?

PM sent, Chris. Thanks. A little more playing around with the gains and delays has got me to this point:

Hi Chris, See the new spectograph below, this has been done with only the basic crossover filters applied but I'm struggling to smooth out the kink at 3,000Hz and there is the small dogs leg between 200Hz & 400Hz. Is there any insight you can gain from the graph??

Thanks, Chris. I’ll drop you a line for the email address, it will be interesting to get an opinion on the filters. When it come to dealing with the delays, is better to use a full frequency sweep done at 1m or at the LP?

I had a play around today with the spectograph and delays in the new version of REW and managed to get to here: I'm not sure where to go from here, even small changes to the timings seem to make the spectograph worse from here........

Thanks, Chris. I've downloaded the beta. I've just re-read your basic guide (below) and I think I may have gone wrong at the outset....... I started from scratch this morning and the process I went through was as follows: First, I loaded the basic crossover points for each driver, first order 400Hz low pass (inverted) for the woofer, first order 400Hz high pass for the midrange and first order 4,500Hz high pass for the tweeter. All good. I then set the umik mic at 1m from the speaker, at my listening position ear height for the woofer and took a sweep within a limited frequency range of 20Hz - 2,000Hz and flattened its response using REW. I then did the same thing for the midrange, mic at 1m from the midrange horn, sweep between 200Hz - 8,000Hz and flattened the response and again for the tweeter, mic at 1m from the tweeter, sweep from 1,000Hz - 20,000Hz. However, I struggled with the levels. Prior to making each individual sweep, I tried to set the levels for each driver at 75db using the pink noise test tone in REW and I used the volume control on the plate amplifiers to level match as far as practical. However, whenever I used my digital sound meter at the mic location to confirm the levels, they were all over the place. What is the correct way to complete these first steps? Should I to set the level with all drivers playing and then simply mute two of the drivers and run a sweep on one driver at a time, without any further level changes, or was my method the right way to do it? 🥴

There must be some differences between my version of REW and yours, I can't get my scales to match up to yours at all. What version of REW do you use?

Ah Ha! 😃 Here is a new graph with a 1.5ms delay added to the tweeter......... it looks to like a further 0.5ms may bring that further in line, which I assume is what I'm aiming for!?

Its going to take me a while to get to grips with all these graphs and how to read them...... here is the group delay plot:

After setting the impulse response to 0 and smoothing to 1/6 the graph looks like this. The little dogs leg is at almost exactly 400Hz Also, the frequency scale is set to db SPL but I cant seem to get the scale to change.

Help! 🤪 After more than an hour I have managed to produce a spectrograph that resembles @Chris A's, however, its dissimilar enough for me to have no idea how to interpret it.... Crossover points are 400Hz & 4900Hz Have I gone wrong here? Can you please educate me on how to interpret this and what kind of delays are needed:

I'm sure its a silly question but here we go........what effect can cabinet fillings have on the frequency response of a speaker?? Can adding a filler material to a bass cabinet have a substantial effect on the lower frequency response of a speaker, such as the la scala. More specifically, could one use cabinet filling to help deal with speaker boundry issue?

Hi Chris! Me again..........😄 I've been having a play with the crossover you sent me and playing around with REW........ it very interesting stuff, even for a novice like me. One thing I was just trying to get my head around was regarding the Delays and Gains. I am assuming these are set based upon the physical dimensions / layout of the speaker drivers and their overall response. If that is the case, can I simply apply these same settings to pretty much any crossover I may wish to design and have the correct delays and gains?? Thanks in advance.

Thanks again Chris! We had a play this afternoon and have tweaked some of the filters as dictated by the REW measurements! All of the graphs show a hefty 15db null at 106Hz: Any guidance on whether this null can be corrected using the HFD software and how would be much appreciated!

The HFD programme has been very good this far, I will be spending some time over the next week or two having a real play with REW, I especially need to work out how the measurements can be gated to take out what the room is doing. That will be interesting. My friend I did some work today and it was very interesting to be able to measure then tweak the filters and actually see the changes to the frequency response! 😃 If you don't mind, I have a few questions regarding the filters that you provided: All of the Low Pass and High Pass filters are first order and I was told in a different conversation that second order filters are prefered for a 3 way setup, is there a reason why you opted for first order over second? Again, during the conversation mentioned above, I was advised that when using second order filters there is a 180 degree phase shift that should be corrected by inverting the midrange driver. On your filter, I noted that the woofer filters have been inverted, why is that? Finally, I noted that the tweeter high pass filter is set at 2500Hz and the spec sheet for the K77 says that the crossover point should be no lower than 3,500Hz. Am I best adjusting the filter in line with the spec sheet? Again, many thanks for all your help with this.

Hi Chris, that file has imported just fine. Thanks. I’ve had a look at the filters, and you can see the delays and gains in the image below. Before I upload the filters, are these figures correct? To answer your questions RE Mute and Sum, the imported settings were correct, Green is on and Red is off. However, apparently, the Sum function only works with measurements done within the HFD programme, so has no effect on the filter graph!! 🙁

Hi Chris, Sorry to pester you but I am really struggling to open this .dat file with the hypex software, do you know how to do it? I tried opening the file in REW but its the wrong format......

All original Klipsch drivers, K77F Tweeter (with Z brackets), K55V Squawker on K401 horns (front mounted) and K33E woofer. I have a friend coming round this weekend to help me with REW measurements etc.

Having now installed Fusion DSP plate amplifiers to my La Scala and dialed in a basic crossover, I have actual music coming from my speakers again! 😃 Big thanks in particular to @Chris A for the patience and pointers. I know there is a long way to go in terms of measuremnets and PEQ's etc, much of which is beyond my knowledeg base at the minute. However, for now, I am just looking to put the speakers back to a basic (listenable) crossover. I have implemented second order low pass and high pass filters, set the crossover points at 400Hz and 4900Hz and inverted the midrange driver to deal with the 180 degree phase shift. However, I am not sure what to do with the gain and delay settings? In order to simply recreate the standard La Scala crossover, what gains and delays should be applied to each driver, if any?

I am just starting to dial in the DSP settings for my clone La Scala but when I read various threads online, I am seeing variations in the mid to high crossover point, some saying 4000Hz, some 4500Hz and some saying 6000Hz. I appreciate that I can tweak this to my hearts content, as and when I am comfortable playing around and measuring but what is the accepted norm for this crossover point? Thanks

I am just attempting to dial in the basic setting on the DSP plate amps for my la scala, the first section asks for the impedeance and the maximum power handling of each driver. I am ok with the impedance but what is the max power handling of the K33E, K55V and the K77M? Out of the box, the amp provides 125w for the woofer, 125w for the midrange and 100w for the tweeter. My initial thought was to leave the woofer channel at 125w, maybe 100w for the midrange and 50w for the tweeter?

I have taken the plunge and bought Hypex NCORE FA123 DSP plate amps for my clone La Scala........... However, I am an absolute DSP newbie. I have taken some Umik measurements of the in-room response, but I would welcome any guidance / pointers on the basic DSP settings I should implement. This is the basic graph with a Psychoacoustic smoothing applied: I would welcome any pointers on where to start here, however, please keep it simple........ I was initially going to follow the guide below on setting-up a basic 3 way crossover with my specific plate amp, but I would really appreciate input from anyone who has advice. https://www.diyaudio.com/forums/class-d/333733-setting-fusion-amp-3-step-step.html Are there any pre-set filters that I could use? Also, I see a lot about "house curves" if anyone can enlighten me?

I bit the bullet and went with the FA123 plate amps....... Watch this space!! 😃

I'm thinking I'll go with the FA123, as this can do both 2 way and 3 way and gives a little more flexability. One of the main things that has put me off going down the DSP route thus far is the thought of all the extra boxes - pre-amp, DSP box, multple power amplifiers etc etc. This unit seems to eliminate all that hastle.