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Help me understand about "frequency response" aspects please?

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Re: Help me understand about "frequency response" aspects please?

Postby James Perrett » Fri Dec 25, 2020 11:19 pm

Treat the MFX as a midrange horn with crossover points set so that it handles the frequency range around 1kHz-5kHz and use something else for 5kHz upwards. Even adding a couple of cheap Piezo horns would be better than trying to get the MFX to work at high frequencies in my opinion.
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Re: Help me understand about "frequency response" aspects please?

Postby mikehende » Sat Dec 26, 2020 11:33 pm

Sam Spoons wrote:But, EQ is rarely able to provide a steep enough slope. You could try setting the Drive Rack mid/high crossover frequency at 600Hz and the slop at 12dB/8ve for the mid and HF power amps, but the horn rolls of pretty dramatically above 10kHz so it is going to lack top end up where I can just about still hear it so probably more so for you and especially your son.

Does that mean it can run at 10k continuously and that is the highest level of highs I will be able to get?
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Re: Help me understand about "frequency response" aspects please?

Postby James Perrett » Sat Dec 26, 2020 11:51 pm

mikehende wrote:Does that mean it can run at 10k continuously and that is the highest level of highs I will be able to get?

From the frequency response it would appear that you only get around half the level that you should at 10k (compared to 2k) and the response drops rapidly after that. However, you'll still get something at 15kHz but nothing like as much as you should. This is a separate issue to power handling - MarkPAMan is probably more experienced than most with those 22A drivers so could probably tell you the optimum size amp to use with them.
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Re: Help me understand about "frequency response" aspects please?

Postby mikehende » Sat Dec 26, 2020 11:55 pm

MarkPAman wrote:It's 20+years since I stopped working for the UK's biggest Peavey dealer, but there's a few things I still remember about their horns

What James said Mark, if you can advise me on how to properly optimize the 22A driver when I get it would be nice? Also, I was told that "Peavy made a near copy of the JBL 2404", would you happened to know what model of Peavey that was please?
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Re: Help me understand about "frequency response" aspects please?

Postby James Perrett » Sun Dec 27, 2020 12:48 am

mikehende wrote:
MarkPAman wrote:It's 20+years since I stopped working for the UK's biggest Peavey dealer, but there's a few things I still remember about their horns./quote]

What James said Mark, if you can advise me on how to properly optimize the 22A driver when I get it would be nice? Also, I was told that "Peavy made a near copy of the JBL 2404", would you happened to know what model of Peavey that was please?

I have a vague memory that the people Mark worked for used a CS400 amp for the highs on smaller systems like yours with the plug-in crossover modules but I could easily be wrong. I used to help them out occasionally but we're talking 25-30 years ago here.
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Re: Help me understand about "frequency response" aspects please?

Postby MarkPAman » Sun Dec 27, 2020 9:12 pm

Sounds about right to me. Always with the amp's built in compressor switched in to help protect the drivers when on dry hire!

I think the crossover had an eq curve built in to flatten the response by taking out most of boosts between 800Hz & 5kHz*, thus extending the flat (or -3dB) response further. Without this in some form, it was not a great sounding driver. The newer 22T is a bit flatter naturally I believe, though I know newer Peavey cabs use other drivers & do not rely only on the one type any more.

*The two most common crossover points were 800Hz & 1200Hz, but there were others available - I guess each had their own eq correction curve built in.
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Re: Help me understand about "frequency response" aspects please?

Postby mikehende » Mon Dec 28, 2020 1:50 pm

James Perrett wrote:Treat the MFX as a midrange horn with crossover points set so that it handles the frequency range around 1kHz-5kHz and use something else for 5kHz upwards. Even adding a couple of cheap Piezo horns would be better than trying to get the MFX to work at high frequencies in my opinion.

That is good advice James [thanks] and might be what I may have to settle for BUT first, I want to try the other options and experiments. That is the setup I have right now but not what I want.

I am hoping PA Man will see my response to his post and can as you've said give me some advice [settings] to optimize the 22A, if not then I will have my bud optimize it to the best as we can hear in the BSS.
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Re: Help me understand about "frequency response" aspects please?

Postby Sam Spoons » Mon Dec 28, 2020 2:27 pm

mikehende wrote:
James Perrett wrote:Treat the MFX as a midrange horn with crossover points set so that it handles the frequency range around 1kHz-5kHz and use something else for 5kHz upwards. Even adding a couple of cheap Piezo horns would be better than trying to get the MFX to work at high frequencies in my opinion.

Go and wash your ears out with soap and water James :D How can you suggest such a thing...

That is good advice James [thanks] and might be what I may have to settle for BUT first, I want to try the other options and experiments. That is the setup I have right now but not what I want.

I am hoping PA Man will see my response to his post and can as you've said give me some advice [settings] to optimize the 22A, if not then I will have my bud optimize it to the best as we can hear in the BSS.

I do agree with JP that you'll never get good sounding 'proper' HF out of the Peavey horns though but at least get a couple of moving coil bullet tweeters or similar, piezo tweeters sound horrible!!!
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Re: Help me understand about "frequency response" aspects please?

Postby mikehende » Mon Dec 28, 2020 2:34 pm

What James said is what a lot of DJ's do, they use the horns for hi-mids and tweeters for highs since they cannot get the highs they want from a horn.
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Re: Help me understand about "frequency response" aspects please?

Postby Sam Spoons » Mon Dec 28, 2020 4:13 pm

Many modern powered speakers can reproduce up to 20kHz from their horn loaded HF drivers, it's the large (effectively mid range) horns popular in the '70s that can't. With a modern speaker additional tweeters are usually unnecessary.
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Re: Help me understand about "frequency response" aspects please?

Postby mikehende » Mon Dec 28, 2020 4:23 pm

Could very well be but I and others maintain that especially powered but also modern speakers does not give the same tone of highs as the older 70s/80s speakers.
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Re: Help me understand about "frequency response" aspects please?

Postby Sam Spoons » Mon Dec 28, 2020 4:53 pm

No, thankfully ;)
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Re: Help me understand about "frequency response" aspects please?

Postby mikehende » Mon Dec 28, 2020 4:54 pm

Fair enough :)
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Re: Help me understand about "frequency response" aspects please?

Postby mikehende » Mon Dec 28, 2020 5:56 pm

OK guys, meantime while I am trying to get he best settings info for the Peavey horn. I just re-read this info here:

https://peavey.com/c/Horn-Equalization

So help me understand it's info please. It shows:

In order for the two transducers to produce the same acoustic level from a loudspeaker enclosure, the crossover must provide for

-10 dB of Attenuation or reduction (Pad) in the signal level of the high frequencies going to the compression driver.

but that is referring to full range speakers, for standalone horn use how would we know how much "attenuation" to apply please? Like in the Peavey Project One, they had to to have done the same thing as it is similar to what I am seeking to do.
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Re: Help me understand about "frequency response" aspects please?

Postby Sam Spoons » Mon Dec 28, 2020 6:21 pm

TL;DR but in a nutshell, the attenuation suggested seems to be for a passive crossover to integrate the horn with a bass/mid driver. If you are using the DriveRack you must be bi/tri amping your speakers and those figures also depend on the power/gain of the amplifiers you are using to drive them. The simple way would be to set all the amps input attenuators to 0dB and balance them, by ear, using the DriveRack. The 'proper' way would be to use a measurement mic and system analyser app but in you garage I think that would be futile and using your ears will yield a better result.

HTH
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