Thank all bros that responded.
My living room is about 7m x 5m. Volume and long throw are not my main criteria. I am looking more for musical quality and warm.
After some researching, a reasonable pair of PA speakers will be between SGD2,000 to SGD4,000. I will set my budget around there.
Weight is not an issue as not moving them around. Will wood cabinet sound better than the plastic cabinet?
Can I use my hi-fi amp like Emotiva, Rotel or Cayin (Tube) to drive PA Passive speakers?
Can I use existing HT subwoofer for both HT and Karaoke?
For mixers, I am researching mixer with built-in feedback eliminator. Echo and key control less important than feedback eliminator. Of course have all 3 better. Alternatively, I will consider a standalone feedback eliminator.
Thank for the info that the shop might be able to help to set up the EQ.
I have 2 neighbors that share a wall and a floor with my living room. So loud output is not possible. Nevertheless, I do not sing loud. Actually mainly my wife singing Chinese songs.
$2k -$4k/pair should get you a very decent pair of PA speakers.
But don't spend too big portion of the $5k budget on just speakers, most important is still the karaoke on demand player, without that there'll be no karaoke.
A small sized mixer cost only a few hundred dollars, a decent power amplifier may cost about $1k, a pair of PA speakers may cost $1-2k, wireless microphone may cost a few hundred dollars for normal ones, cheap ones also usable.
I still think it is important to go down to the shop and let them allow u to test out the speakers before buying, best if they have a microphone for you to test.
Very hard to say "warm" or "music quality" over the internet. Because how warm or bright really depends on the type of drivers used in the speaker, and how the speaker itself respond.
I have a speaker with High freq horns that favours frequencies from 1kHz and above, making it sound bright, so i used the equaliser to tune it to make it "warmer" and less harsh.
Also take note that some of the High Freq horns of PA speakers are very harsh sounding, it will be tiring to the ears after listening for long hours.
These may be good for clubs to reproduce the high harmonics for techno/dance music, but may not be suited for other applications. Best to listen personally.
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In my opinion, i felt that generally wooden loudspeakers sound better than plastic ones. But plastic loudspeakers still sound decent, not bad sounding.
The following is a very short video recording of how my plastic PA speaker sound at an exhibition. It is a typical plastic loud speaker with a 12" LF driver.
In the video, i am running a pair of 12" 2 way PA Speaker which are pole mounted on a pair of 18inch subwoofer.
It was recorded through a handphone, so it is not an accurate representation of how it really sound, it's just to give a rough idea.
Not sure if you can see the speakers, they are black and placed against the big black wooden board. The width of the board is about 10+ meters. A pair of 12" speaker w subs is good enough to fill this small indoor area with light music.
As the PA speaker is very sensitive, i do not need much power to produce the Sound Pressure Level (SPL) required.
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Yes, technically you can drive PA speakers with audiophile amplifiers that you have, I remember amplifiers like emotiva, rotels, mcintosh have quite a bit of power with low Total Harmonic Distortions.
However, some may find that it is a 'waste' to drive PA speakers using audiophile amplifiers as high end audiophile amplifiers are built for high fidelity. In contrast, a cheap PA may not have as high fidelity as an audiophile speaker, then again, it is really up to the purpose and application, there's no harm trying n experimenting if done correctly, it is very fun.
Moreover, as PA speakers are more sensitive than some audiophile speakers, PAs will be easier to drive.
PAs have sensitivity of about 96dB/w/m and up, while some audiophile speakers have sensitivity at about 80+db/w/m (if i rmb correctly). In very simple terms, without considering too much factors, take it as with 1 watts, PA speaker with 96db/w/m can produce approx 96db at 1 meter (usually at a single frequency of 1khz). Thus people say PA speakers (or highly sensitive speakers) are "easier" to drive.
But these numbers are not always so accurate, especially when more frequencies are being input into the speaker.
Also, as most passive PA speakers use "speakon" connectors(some call it "professional twist and lock"), you may need to terminate one end of your cables to fit this "speakon" connector if your current speakers do not already use speakon.
In simple terms, it is just a connector type with electrical contact points being housed into a plastic casing.
Note: some of these speakon connectors/receptacles have 4 terminals to
run 2 sets of wire in 1 connector (Note its technical name). 2 sets of wires will have 4 wires, or 4 poles
This is good when biamping a single PA speaker, some PA speakers can be tri-amped as well.
One thing to note if u intend to drive PA speaker with audiophile amps (applies to any amplifier as well) will be the impedance of the driven speaker.
Like many speakers, PA speakers can have impedance of 8ohms or 4ohms. If you want to use your audiophile amps to drive the PA speaker, best to check the specifications of the amplifier and see the output power vs impedance. Try not to spoil the amplifier as i believe the ones you can easily cost much more than the PA speakers.
Another thing to note will be the Headroom of your audiophile amplifiers. Karaoke is a "live system", the source of sound comes from the microphone. If one day your friends come over and scream loudly into the microphone while singing, the amplifier will try to amplify the loud screaming (think high signal level), and the resultant instantaneous power demand may be quite a lot.
If the amplifier doesn't have enough headroom to handle this transient peak in signal, it can result in a clipped signal (some call it "not clean" signal) being sent to the speaker, which will cause damage when done continuously.
(Not being able to keep up w the transient will also result in something called slew rate distortion)
Examples of continuous clipping will be: using an amplifier that does not have enough power and trying to turn up the volume till it sounds distorted. Or trying to sing karaoke with an amplifier that does not have enough power for the speaker to produce the desired loudness, but still turning up the volume till it distorts.
The following picture shows the "nameplate" of a typical PA speaker. A power rating of 300W continuous is quite normal for a not so high powered PA speaker. Note the speakon connectors, sensitivity, impedance.
Usually for a 300Watts continuous (or some say 300 Watts RMS), it is recommended to use an amplifier with 1.5x the continuous rating of the loudspeaker. i.e 300W x 1.5 = 450Watts. This will give it some slight headroom to handle the peak signal
For more demanding applications, people tend to use amplifiers with higher power rating for more headroom.
Of cos, another method to control this peak in microphone signal is to use a compressor like what nastromo mentioned.
There are standalone compressors that can be inserted(electrically, not physically) between the channels of the mixer, and also basic ones that are built into the mixer. By compressing, the peak signal, low level signal and transient will be lowered, resulting in a signal which is "smoother" n more uniform in terms of magnitude. Some describe it as "making the soft part loud and loud part soft."
Then again for home use, we may not need amplifiers which are too powerful.
The process of choosing and pairing an amplifier with a speaker may be a bit confusing to some, thus they will prefer to buy active speakers, as the amplifier has already been properly matched(hopefully) and built into the speaker by the manufacturer.
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Yes, technically, HT subwoofers can be used with your PA system, but here is the part that gets a bit tricky.
For HT, the AVR have the "LFE/sub woofer" out. The AVR have crossover built-in to help to send the high frequency to the speakers and send the low to the subwoofer.
But for a traditional PA systems, there is no crossover built into the mixer, which means this job is not done automatically.
The output of the mixer is a full range "XLR Left and XLR Right". In a normal system, these output signal from the mixer will be sent to a crossover, and finally to the power amplifier.
Thus, you will require a crossover to properly integrate the HT subwoofer with the PA speakers.
Else if there is no intention to use a crossover, you can still run the HT sub, but rmb to set the low pass/high cut to the lowest freq respond of the PA speaker, or any other points which u prefer.
Some Active subwoofers with crossover built in will accept the full range signal and help to output the high frequency signal to the speakers.
From here it can be seen that a PA system is quite "modular" (external compressor, external crossover, external feedback destroyer, etc), there are many physical modules for specific applications that can be added in or taken out.
Due to the different types of crossovers, equalisers, amplifiers, compressors, other external modules, PA systems may be more troublesome(in some way ) to set up compared to a HT system; but the advantage is that these external modules in a PA system may offer more parameters to fine tune.
(Fortunately, some companies like dbx design products that take over the job of all these "external modules", some of such products will be the dbx go rack that nastromo mentioned. Im using the dbx driverack 260 myself.)
Also, as PA speakers can get very loud very easily, sometimes the PA speaker may "over power" the HT subwoofers. I usually run 2 x 18" subwoofers with a single 15" PA Speaker, else it is hard for the sub to "keep up" at high SPLs.
Then again, im aware that some HT subs can get very loud and dig very low, eg. the SVS PB13 Ultra, but i didn't get a chance to try out high power HT Subs with PA speakers. Maybe you should experiment with it. It is fun to try.
Also note that mainstream not so expensive PA subwoofers wont be able to produce 20hz at 110db like what ht subs can do. Though there are big sized horn loaded PA subs designed just to reinforce the lows, usually used in clubs/cinema.
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Some mixers do come with "Feedback Detection", but not sure which one comes with eliminators.
The "Feedback eliminator" that you are talking about and what nastromo mentioned is the "automated" process of "eliminating feedback using an equaliser".
These feedback eliminators will automatically detect which frequencies are causing the feedback and automatically attenuate them.
Some of my friends felt that if you are already using an equaliser to attenuate the "feedbacking" freq(in other words "ring out" the room), there isn't really a need to use this automated feedback eliminating devices anymore (or vice versa).
But in my opinion, as long as both devices are not set to contradict each other's setting, using them together is possible as some of these "anti feedback" system have a "live mode".
"Live mode" means it continuously detect if there's a feedback, and if there is a feedback, it attenuate that freq automatically (for a short few seconds), while you are using the system.
The reason why this "live mode" exist to continuously detect feedback is because sometimes singers will hold the mic n walk around the performance location(eg stage), and this could induce feedback.
Im using a device similar to what nastromo recommended, he recommended the dbx gorack, im using the dbx Driverack 260
Here is what the "active feedback screen" looks like:
Note: the "F" stands for fixed filters, while the "L" stands for live filters.
I hope it is not too confusing, i feel it is important to know these minor differences between audiophile/HT system and a Professional audio system, hopefully these will help u consider more when buying a PA system.
There are more details for karaoke stuffs to look at such as setting the gain of the mic and overall gain structure of the PA system to gain the signals at each stage to an acceptable level for the device at the subsequent stage, something similar to pre-amping the signals in an audiophile system
PA speakers are built to be loud as they need to reinforce the sound in a noisy environment(shopping center, outdoor, concert hall, cinema), so their purpose is slightly different from audiophile/HT systems.
Cinema also use PA speakers, such as:
https://www.qsc.com/cinema/products/loudspeakers/screen-channel-loudspeakers/2-way-bi-amp/sc-322c/
The KOD system i will ask my friend to post here, or i will post after i get the info from him, that one im not familiar, i do more on the PA system side.