I recently finished up a 2a3 SET amp. While I'm quite happy with the results, I now feel like it's exposing other weaknesses in my system. My main complaint is that vocals (depending on the range of the vocalist, often middle to higher) are a bit grating to my ears and take away from my enjoyment when listening. What I'm looking for out of this thread is to hear what others might have to suggest. I have ideas of what I want to do, but I know many have been down the same road before, and I'd love to hear from practical experience. Thank you!
What I have now:
I currently have a three-way horn system that I put together 4-5 years ago and had been "good enough" for most of that time. It started life as a single JBL C34 with an 001 load. I found another C34 in decent shape, pieced together more components, and had a system that looked something like this:
Changes I've been thinking about:
I know that the C34 cabinets aren't the strongest choice. I'm all for a DIY build for a bass cabinet though. Space is somewhat of a limitation, only because of the size of my home. The room is roughly 12' x 18' (3.65m x 5.48m), and the speakers need to go along the shorter wall.
I've played around with the Altec 806A's since getting them and I like how they sound, though the same issues still show up with a level of harshness that I can't seem to tame without sacrificing detail. Of course, this is just inserting them into the system I've been using, so they're crossed over at 1200hz instead of the 800hz they would have been in the Valencias. I also think I'd like to go in the direction of multi-cell horns, but size comes into play there.
With the 075's, I've wanted to sell them and replace with the 077/2405 for a while. One day soon I'll actually get around to it.
As for crossovers, I'd love to keep it DIY for cost purposes, but I've also been eyeing Werner Jagusch's for a while.
What I have now:
I currently have a three-way horn system that I put together 4-5 years ago and had been "good enough" for most of that time. It started life as a single JBL C34 with an 001 load. I found another C34 in decent shape, pieced together more components, and had a system that looked something like this:
- JBL C34 cabinets loaded with 1x 130A driver each
- JBL 2410 mounted externally w/ Fostex 420 teak horns
- JBL 075 bullet tweeters also mounted externally
- DIY crossover build that is essentially just a JBL N1200 and a N8000 incorporated together using Jantzen CrossCaps, air core inductors, and L-pads that were affordable to me at the time.
Changes I've been thinking about:
I know that the C34 cabinets aren't the strongest choice. I'm all for a DIY build for a bass cabinet though. Space is somewhat of a limitation, only because of the size of my home. The room is roughly 12' x 18' (3.65m x 5.48m), and the speakers need to go along the shorter wall.
I've played around with the Altec 806A's since getting them and I like how they sound, though the same issues still show up with a level of harshness that I can't seem to tame without sacrificing detail. Of course, this is just inserting them into the system I've been using, so they're crossed over at 1200hz instead of the 800hz they would have been in the Valencias. I also think I'd like to go in the direction of multi-cell horns, but size comes into play there.
With the 075's, I've wanted to sell them and replace with the 077/2405 for a while. One day soon I'll actually get around to it.
As for crossovers, I'd love to keep it DIY for cost purposes, but I've also been eyeing Werner Jagusch's for a while.
Attachments
I have found that peaks in the 2 kHz to 3 kHz range can be annoying for vocals.
My approach would be to measure the frequency response of your system with Room Equalization Wizard and a microphone. Look for peaks in the response in the vocal range. You can use an equalizer (parametric is best) to reduce any peaks found and see how that sounds.
If that fixes the problem, you can add a notch filter to your crossover or at line-level.
My approach would be to measure the frequency response of your system with Room Equalization Wizard and a microphone. Look for peaks in the response in the vocal range. You can use an equalizer (parametric is best) to reduce any peaks found and see how that sounds.
If that fixes the problem, you can add a notch filter to your crossover or at line-level.
Do you equalise? It may help some areas but can also help you identify problems.
That's one way diffraction manifests. While I can't be sure what your specific problem is, I can see that wide but short mouths can't hold lower frequencies.. they are expected to let go.
Hello
Looking at the schematic of the N1200 how did you work out the attenuation on the Compression Driver? It uses a tapped inductor and a selectable resistor value. Have you tried adding a bit more attenuation besides the potentiometer?
Just a wild A guess but if you are getting some "harshness" couldn't hurt to look into it as it could be a relatively easy fix.
Rob 🙂
Looking at the schematic of the N1200 how did you work out the attenuation on the Compression Driver? It uses a tapped inductor and a selectable resistor value. Have you tried adding a bit more attenuation besides the potentiometer?
Just a wild A guess but if you are getting some "harshness" couldn't hurt to look into it as it could be a relatively easy fix.
Rob 🙂
I'll definitely plan to play around with Room Equalization Wizard. I actually didn't realize that a free software existed for this purpose. Thank you for this suggestion!
I don't, except for when playing digitally, I will make some light adjustments.
While playing around with the one large multi-cell horn I have, I've definitely noticed this. It seems to tame the unpleasant frequencies better, or maybe it's more effectively reproducing the lower frequencies.
@Robh3606 Let me see if I can do a quick schematic of the changes I made today. For some reason I don't have one on hand right this second.
I have a bi-amped JBL speaker system which had an issue with a frequency response peak in the region of around 2.1 kHz. The effect of this was not always noticeable, but when certain female singers were played back, some notes in the frequency range were emphasized making for an unpleasant listening experience.
I identified the problem with frequency response measurements and configured my active crossover with a notch filter to eliminate the peak at 2.1 kHz. The crossover also adds some bass boost. The attached graphs show the unequalized (blue) versus equalized (red) frequency responses at my listening position and the frequency response of the active equalizer.
The difference in the listening experience was huge. The notch filter is quite narrow and not very deep but very effective.
I used to have a pair of Klipsch Cornwalls from the 1970s and I only used them for the bass frequencies. However, when I went to sell them a few years ago, I restored them to full range. When I tested them out prior to demos, I encountered the same frequency peak issue in the 2 kHz to 3 kHz range. This is probably the horn "honk" that people hear. I used a line level equalizer to tame the peak and the Cornwalls sound quite nice, although not as nice as the JBL system.
I identified the problem with frequency response measurements and configured my active crossover with a notch filter to eliminate the peak at 2.1 kHz. The crossover also adds some bass boost. The attached graphs show the unequalized (blue) versus equalized (red) frequency responses at my listening position and the frequency response of the active equalizer.
The difference in the listening experience was huge. The notch filter is quite narrow and not very deep but very effective.
I used to have a pair of Klipsch Cornwalls from the 1970s and I only used them for the bass frequencies. However, when I went to sell them a few years ago, I restored them to full range. When I tested them out prior to demos, I encountered the same frequency peak issue in the 2 kHz to 3 kHz range. This is probably the horn "honk" that people hear. I used a line level equalizer to tame the peak and the Cornwalls sound quite nice, although not as nice as the JBL system.
Attachments
'Honk' in music is in the ~450-900 Hz BW where traditional prosound XO point horns amplify most and presumably why Altec's shift to 1200 Hz to bypass it for HIFI apps as its cast metal sectoral horns are particularly egregious.