noob here, does anyone do measurements of pro audio speakers?

[stagehanddan]

I am always on a budget and I have had a nice experience with an Alto Professional Truemix 800 analog mixer doing sound in a small venue.

I would love to upgrade the speakers to JBL EON710s but they are expensive. The reason why I like them is that they are bi-amplified and have a built in parametric EQ so I can correct their in room response and that should give me good sound.

But I'm on a budget so with that good experience with Alto Professional, I'm looking at the Alto True Sound TS408 speakers. They have similar electronics to the JBLs but they cost half as much.

I'm looking at the 408s because I am more used to home Hi-Fi where woofers larger than 5.25" are usually hard to cross over to a 7/8-1" dome tweeter resulting in frequency response issues in the midrange. I don't really have any knowledge of compression drivers and horns so I don't know how much of a crossover issue there is with larger drivers but lots of PA speakers are 2-way designs with 15" woofers so I'm not sure if they sound bad or live sound just sounds worse than a studio record.

Compounding my lack of knowledge, I can't seem to find independently tested frequency response graphs on the TS408s (or anything else but I really haven't been looking for anything else).

I am also thinking of pairing them with Alto's new 15" subwoofer to fill in any bass that the TS408s might be lacking. Unfortunately these subs don't have a parametric EQ, just a few crossover frequency settings and a 0-90-180-270 phase switch.

On the lucky side, I was given a Bheringer X32 mixer which was left outside in the rain and has a mold issue. If I can clean that off and get it working, I can learn how to use the RTA features of the mixer and use it to ring out the mics.

So should I worry about the sound quality of the TS408 speakers? The reviews seem good but they are all subjective, no graphs, but if I have an X32 to EQ everything and a calibrated mic, can I fix any flaws that the subjective testers might have missed?

And on to calibrated mics: Bheringer sells one for $35. It is supposed to have flat response and I wonder if relatively flat is enough to EQ bumps and dips out of speakers that aren't so flat?

Does it make sense to spend another $65 on a mic that has a calibration file if I don't worry about +/-1dB here and there?

Thanks for any help, Dan

 

[Keith_W]

Hi Dan, welcome to ASR.

Does anyone do these measurements? The answer is yes - both Amir and Erin do measurements of pro audio speakers. You can search for Amir's reviews on this site, and you can find Erin's reviews here or on Youtube. Unfortunately, neither Amir nor Erin have reviewed the Alto TS408. I did a quick google search for you, and like you, I found nothing but subjective reviews.

Pairing a large woofer with a tweeter on a flat baffle which is not tapered or shaped for the tweeter may not only cause FR issues at the crossover point on an axial measurement, but it will likely affect the directivity of the speaker which you will only see on a spinorama. More specifically, the tweeter might beam like a flashlight and whilst the woofer will be more omni. This will cause the spectral content of reflections to be distorted, and there is nothing you can do about it, not even with DSP. DSP only corrects the axial response. Attempting to correct for off-axis will distort the axial response, and vice-versa. I would suggest avoiding any speaker where there is no published spinorama, particularly if it is for professional use.

If you use DSP, then subwoofers don't need to have any features like PEQ and phase settings. They only need volume control. I personally think that anybody who wants to use subs needs to use DSP. Attempting to integrate a sub any other way will result in an imprecise/incomplete correction.

And yes, you could use your $35 uncalibrated Behringer mic. It will give you some information, but it won't be good information. It all depends on how meticulous / OCD you are about quality.

For recommendations on objectively good studio speakers, may I suggest you try a pro audio forum? Most of us here are home audio enthusiasts. Some of what we think might apply to you, but pros have specific and more stringent requirements than home audio enthusiasts. I suggest you download and read the EBU 3276 document here. You will find a list of directivity requirements for speakers and acoustic targets for studios.

 

[Vladimir Filevski]

So should I worry about the sound quality of the TS408 speakers?

Yes. It is a cheap loudspeaker, which sound quality can not be improved with EQ. Do not expect much form it, it has only 8" midbass unit. In the PA world 8" midbass is just a toy, especially if used without subwoofer. Good only for background music or karaoke in a small cafe or pub.
If you want to make real sound reinforcement in a (very) small venue, I would suggest at least Alto TS412 (or something better). For a start, do not mess with DSP EQ other than basic settings - you don't need a measurement microphone for that, use your ears.

 

[stagehanddan]

Yes, I know off axis is an issue, especially when you're trying to cover an area, not a single sweet spot. I would assume that pro audio speaker manufacturers should be even more aware of that than home audio just because of the way pro audio speakers are used.

I hope that Alto designed them properly and the subjective reviewers were not missing a huge fundamental flaw.

On to the measurement mic, I would probably only try to tame peaks and dips that were consistent on and off axis and just try to make frequency response look relatively smooth. I wouldn't do a spin test but I could move the test mic all over the listening area to see what is going on.

I would be doing all of this for a permanent install and I don't mind if it takes me 2-3 days to thoroughly test it and adjust it if the result sounds nice.

The most demanding audio in the space would be karaoke but I would want to do it right and learn how to nail the setup in the process.

 

[dasdoing]

as a rule of thumb with professional audio: whenever you opt for cheap solutions, in the long run, you end up paying twice as much as if you had bought the better quality right away

 

[DVDdoug]

Often you can rent equipment and that may be the best way to figure-out what works for you.

All speaker designs involve trade-offs. In a PA system you want efficiency, loudness, and power handling. Also usually ruggedness, light weight, and portability but that's not as important in a permanent installation.

The "sound" will depend largely on the room and to some extent that can be fixed-up with EQ.

With most "small bands" the PA is for the vocals (or mostly for the vocals) with most of the sound coming from the stage. You may not need a subwoofer or much bass. And if you do, it takes a lot (big subwoofers or multiple subwoofers and lots of amplifier power) to match the bass coming from the bass player's amp/cabinet and the sound of a kick-drum.

For a DJ setup, sound quality is more important, but "loudness" (and reliable loudness) is also important. But usually in those environments there is a lot of crowd & "people noise" so you don't really need "studio quality". You do need "full frequency response" with strong bass and strong highs but you probably don't really need flat frequency response.

There's also a trade-off in the bass range. Most pro subwoofers are "tuned" to "only" go down to around 40Hz. That's about the lowest note on a standard electric bass guitar and it's low enough for bass you can feel in your body. By not trying to do down to 20Hz they can get more efficiency & bass loudness to fill a large venue with a bass you can feel.

I'm looking at the 408s because I am more used to home Hi-Fi where woofers larger than 5.25" are usually hard to cross over to a 7/8-1" dome tweeter resulting in frequency response issues in the midrange.

That's not necessarily a problem, but with larger woofers 3-way designs are more common (especially in home speakers and studio monitors). Horn tweeters often cover a wider range, down more into the midrange. They might fall-off a bit at the highest frequencies, but not always. And the woofer might be compromised on the low-end to get more midrange (even with a larger woofer).

Most "PA speakers" are good in the midrange because voice is very important.

 

[stagehanddan]

The TS412 recommended has a 12" driver in a two way design. I just worry about cone resonance causing problems because the cone is so large.

If I can get the TS408s to cross over to a sub at a decent frequency I don't think volume will be a big issue. The venue is only around 2,000 ft^2 and PA speakers are designed for high output.

I am familiar with rental gear. I have set up lots of QSC K10.2 speakers in larger conference rooms. They aren't doing Karaoke but they handle it easily. My room is probably 1/3 the volume of a conference room that a pair of K10.2s fill just fine. I want the TS408s because I'm doing a permanent install which will allow me to optimize the setup. I want to have that parametric EQ to take care of room modes. Then if I can get that X32 working I can use it's EQ to prevent microphone feedback and any other adjustments I need.

The goal is great sounding Karaoke and background music for other events. I don't think I need to fly line arrays or anything crazy like that.

 

[Vladimir Filevski]

Don't worry about the non-existing cone resonance of 12" drivers - it is a common size for a high-quality 2-way PA loudspeakers. Additional advantage over TS408 is that you don't need a subwoofer with TS412, just adequate EQ in the low region. For a small venue and not-so-loud karaoke maybe even TS410 will suffice. TS408 is useless without subwoofer.

 

[EERecordist]

Welcome to ASR!

That size room and your use cases, background and karaoke, you will not stress the sound system. If you had DJs who want to be well over 100dB A scale SPL and with a lot of bass, you might consider a more professional speaker. The X32 is a very popular standard reasonably-priced mixer. I may sound like a "broken record" because I often suggest the current model of the DBX Drive Rack and a calibrated microphone. It has a pink noise generator and auto-eq with the microphone. In that case, you don't need the parametric EQ in the speaker to flatten the room.

You are already knowledgeable about mid-price professional speakers from JBL, QSC, Mackie, EV, and Yamaha. Usually I would say the ability to have them repaired over years and reliability engineering is important in picking PA speakers. If you ever have visited a major trade show, especially CES, you will find dozens of Chinese manufacturers with unknown reliability engineering and certainly not repairability.

Alto is an interesting case because they have been owned by Numark for about 15 years, a lower price DJ equipment maker, and they have a 2 year warranty. I would read reviews on Alto to learn other customer experiences. So if they are not going to be stressed, they are a throwaway speaker in installed sound. Behringer has similar throwaway speakers, Behringer is part of a very large audio vendor group with professional offerings. The more complex the plate amp with PEQ, the less likely it will be repairable or replaceable.

I would suggest bumping up your mains to a 12 or 15" LF driver, even in the Alto line. Musicians go in and out of equipment all the time, so I would suggest buying mid-price professional speakers used. Churches also sell their old AV gear. Driveracks are available used, though I would recommend the current version which has an iPad/laptop user interface. And I would suggest the Driverack+microphone and for the cheapest sound level meter, the NIOSH sound level app for iPhone. I would also take into account that the venue owner might book something in the future that uses 100+ dB levels and blows the speakers for which you would be blamed. The Driverack has a limiter for that. Set up and EQ your system with mains, then decide later if you need subs, which are expensive. Maybe your dealer will allow you to borrow a sub which you could return if it is not needed to combine install and evaluation into a compact schedule.

 

[1st.Virtual.Me]

I can't seem to find independently tested frequency response graphs on the TS408s (or anything else but I really haven't been looking for anything else).

QSC K10.2 are on QSC's site and here:

Measurements for speaker QSC K10.2

www.spinorama.org

A great speaker and company. A great warranty.