Coaxial vs Component Installation and Out of Phase Rear Fill?

[Kiad 10+ year member]

If I'm going to mount the tweeter on top of the midbass cone anyway in my system, does it getting a component make a difference? Isnt a coaxial with a directional tweeter the same thing (assuming all else being equal)?

I was going to get an Image Dynamics CXS64 6.5" but my custom shop is telling me that it wouldnt make for a clean or economical install given how far along they are with the upholstery. This unit can also be mounted like a coaxial, but if I'm going to go with that option, a regular coaxial would be cheaper for the same sound no?

The audio specialist there also suggested that given this limitation and the size of my car (cadillac fleetwood), they would want to keep my rears speakers and run them out of phase to raise the sound stage for SQ. I know everyone generally dislikes rear fill here, but can this actually work?

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[troy_audi0 10+ year member]

if they have them run at a lower wattage & vol.

the Image Stuff is great,

You could also call ID

 

[Kiad 10+ year member]

Another question...the 6.5 IDs have a recommended RMS of 150watts. My original plan was to bridge my amp but if the rears need power now I can only feed 75 watts to a channel. I know underpowering the IDs wont damage them unless I get into clipping territory, but would the SQ suffer by being powered at half the recommended RMS?

Some people say that underpowering a speaker like this is nothing more than playing the speaker with the volume turned down, but if thats the case, why list recommended RMS at 150 watts which would make you go deaf in a car? Wouldnt listing a range of "recommended" RMS make more sense? I've read a few people on this forum refer to some speakers as "power hungry". How does that term make sense given the above?

 

[troy_audi0 10+ year member]

you could still run the amp the same & do the rears off the deck power..

more power up front is the way togo, if you run less power than RMS you may get distortion when you crank it up thats what damages the speakers..

 

[DidUHearThat? 10+ year member]

If I'm going to mount the tweeter on top of the midbass cone anyway in my system, does it getting a component make a difference? Isnt a coaxial with a directional tweeter the same thing (assuming all else being equal)?

It would be true, except usually all else is NOT equal. From the same brand components usually have better quality drivers and better passive crossovers than co-axials. I have heard a few very good co-axials, but they are rare. 99.9% of the time you will get much better speakers for the same money with components than co-axials. They do make components that can be stacked like co-axials (which is what I think your suggesting below) that would work fine.

I was going to get an Image Dynamics CXS64 6.5" but my custom shop is telling me that it wouldnt make for a clean or economical install given how far along they are with the upholstery. This unit can also be mounted like a coaxial, but if I'm going to go with that option, a regular coaxial would be cheaper for the same sound no?

A regular co-axial will not sound as good.

The audio specialist there also suggested that given this limitation and the size of my car (cadillac fleetwood), they would want to keep my rears speakers and run them out of phase to raise the sound stage for SQ. I know everyone generally dislikes rear fill here, but can this actually work?

Don't run them out of phase. Run them correctly, but at a lower volume.

 

[Cameron_B 10+ year member]

I don't really know much about the subject, but how does the "audio specialist" come to the out of phase conclusion?

Can someone explain what the advantage to running them out of phase?

How could you tell at around 3-400hz?

 

[DidUHearThat? 10+ year member]

Another question...the 6.5 IDs have a recommended RMS of 150watts. My original plan was to bridge my amp but if the rears need power now I can only feed 75 watts to a channel.

Focus your money and energy on your front speakers. Don't worry so much about the rear, you won't hear them anyway.

I know underpowering the IDs wont damage them unless I get into clipping territory, but would the SQ suffer by being powered at half the recommended RMS?

Some people say that underpowering a speaker like this is nothing more than playing the speaker with the volume turned down, but if thats the case, why list recommended RMS at 150 watts which would make you go deaf in a car?

You will lose headroom as well as volume. Bass notes in particluar will hog most of that power range, and it will disappear quickly and leave you wondering why it's already distorting at medium to low volumes. You will regret not having more power if your speakers can handle it.

Wouldnt listing a range of "recommended" RMS make more sense?

It would, some companies do that, but most people have trouble understanding specifications anyway and that would just confuse them further. Audio companies usually lose market share by being honest, and the ones who lie sell big to the masses of people who don't know any better. Power handling usually refers to the maximum thermal power handling of a speaker. Expressed in either RMS or peak power. It would be helpfull to know how long it can handle that much power. In pro audio the power rating is for 1 hour at that power level. In consumer audio it's usually just short periods of time, but it gives you a general idea of what to shoot for.

I've read a few people on this forum refer to some speakers as "power hungry". How does that term make sense given the above?

Power hungry is a vauge term that can mean either the speakers have a low sensitivity and require alot of power to get loud (compared to speakers with higher sensitivities), or that they can handle a lot of power and perform best when fed all that they can handle. Usually people mean the latter.

 

[DidUHearThat? 10+ year member]

I don't really know much about the subject, but how does the "audio specialist" come to the out of phase conclusion?
Can someone explain what the advantage to running them out of phase?

How could you tell at around 3-400hz?

There are no advantages. At bass/low mid frequencies, with cabin effect, this will cause increased phase cancellation in the cabin and rob your system of warmth and bass (even up front), and probably lead to premeture failure of your rear speakers.

I've heard some pretty strange theories about how to set up rear speakers like that or running them with a 2 kHz LPF or 500 Hz HPF or wire one out of phase, woofers only, tweeters only, etc.

IMO, all completly unnessesary.

People forget to simply adjust the FADE knob and turn down the rear speakers. I like rear fill, but front stage is the only thing that really matters.

 

[Kiad 10+ year member]

There are no advantages. At bass/low mid frequencies, with cabin effect, this will cause increased phase cancellation in the cabin and rob your system of warmth and bass (even up front), and probably lead to premeture failure of your rear speakers.

I've heard some pretty strange theories about how to set up rear speakers like that or running them with a 2 kHz LPF or 500 Hz HPF or wire one out of phase, woofers only, tweeters only, etc.

IMO, all completly unnessesary.

People forget to simply adjust the FADE knob and turn down the rear speakers. I like rear fill, but front stage is the only thing that really matters.

Thanks for the help. The audio guy at the shop did mention there was a trade off at the bass/low frequencies when running the rears out of phase but said "you will actually be able to literally hear the stage rise as I tune the amp".

Unfortunately, he claims I should run the rears off the amp as well because the head unit probably doesnt offer the flexibility or fine tuning necessary to do what he needs. We'll see I guess.

I think I'll let him try it his way and see if it works and report back. My ears are more sensitive to poor stage height than anything else. I'll know he succeeded if my cabin sounds as good as my Ultimate Ears Super-FI 10 earphones (best 350 bucks you can spend btw). If not, I'll just bridge the amp and run the rear off HU power in phase.

Can a person really run more than 75 watts to a speaker and not have his ears bleed? I listen to my music at a volume that makes me confuse sirens in a song for real sirens from a cop car driving right next to me. Dangerous I know...freaks me out sometimes. But anyone have a rough idea how many watts it takes to do that? I remember someone telling me thats probably not even 50...

 

[DidUHearThat? 10+ year member]

Any speakers will sound better run off an external amp instead of the HU. My head unit does not even have a built in amplifier. I run my rear speakers off an amp as well.

But your main focus of dollars and attention should be to your front stage. Rear speakers are really pretty irrelevent. I have them mainly because I use the back of my van as an RV for sleeping (and at the drive-in)and the rear door opens upward to act as a small roof that we sit set a table up under when it's raining and it's nice to have the speakers up there. The stock speakers where intollerable at any level.

I don't think your rears will help to "rasie" your sound stage. That will just pull your imaging to the rear. Speakers further away from you causes more cabin effect and room reflections, rather than near feild where you hear the speakers directly with fewer reflections.

You can raise your front stage easily by installing your tweeters in your "A" pillars or using supertweeters like the CDT IEK set up I have. But even from the floor, good speakers will sound great.