10s vs. 15s

[BassyBill]

I used those two speakers to illustrate the difference of the Vd spec between a 10 and a 15 and that surface area alone doesn't tell you much. You're right, the volume of air a speaker can displace is of no consequence...unless you want to be heard past the first row of seats that is.

Maximum displacement of a driver won't help much if the voice coil's hardly moving below 80 Hz. Yes, you need to "move air". But you need to move it in a way that creates pressure waves across the frequency range you're trying to reproduce.

This is the whole point - frontal area and maximum displacement don't tell the complete story. You need to consider the frequency plot of the drivers in the enclosure they're sitting in, and there's a heck of a lot of things that affect this, cone displacement just being one of them. If manufacturers published plots showing this we'd be having a completely different discussion.

 

[theshadow2001]

I said I'm with Bill on this one because like him I tend to think that combinations of drivers are the way to go. Look at any decent sound system (hi-fi, PA, whatever). I think if you want to cover a wide range of frequencies (and amping basses comes into this category) then you're not going to do it as well with a single size of driver, even in multiples, as you are with specialist ones for each frequency band. I know bi-amping, like Hartke , is out of favour amongst bassists at present, at least on this forum, but to me it's intuitively the best engineered solution for the job, passive crossovers being a close second (for efficiency reasons). My requirement for a bass amp is clarity across the full range of frequencies and my Hartke bi-amped setup gives me this. Whenever I've tried just using a 410 or, way back, a 412, the sound was too "coloured" for me.

Just what I prefer I guess. I know a lot of guys like less of a hi-fi sound (I use this term in the clarity sense, rather than the scooped mids sense common on TB - I don't associate biamping with a scooped sound, nor is there any reason why it should be AFAIK).

Although you say bi amping or tri amping is the best soloution for the job it does it make much sense to this when most comercial bass cabinets dont cover specific frequency ranges? I would agree with bassybill though most stereo's are bi or tri-amped with different speaker configurations for a reason as are PA's. However it seems getting a commercial bass cabinet to do a particular freq range is difficult.

Do you think that bi amping is still a good idea when using full range bass cabinets which seem to be the standard. From what I gather a full range cab is usually good at lows or highs or somewhere in between but not good at both ends of the spectrum?

 

[Stumpy]

I'm sure this one has been done before, but can I get some help on the difference between 10' speakers and say 15s or 18s in terms of sound, tone, etc?

Curently playing Ampeg 8x10 in drop C tuning and seems like the 10s fizzle out on the low notes when I dig in. Just wondered if a larger speaker could handle it better.

I dunno about the drop C, but on my B string (.135) the Metro (Eden) would only hold most of its own. I put a single 15" cab underneath it and rattled my legs.

I am now experimenting with a 210xst (Eden) because the frequencies are lower and I like the speed of the 10's as opposed to the 15 or the 18.

Just my thoughts.

Stumpster

 

[specplyrz]

"I would agree with bassybill though most stereo's are bi or tri-amped with different speaker configurations for a reason as are PA's."


Most "stereos" that I have owned, and I have owned a few....were NOT bi or tri amped. Are you speaking of the typical stereo speakers being two or three way?

Now you CAN bi amp a home stereo system, some high end speakers have the option of removing "jumpers" between the terminals, thus allowing two amps to be used. Usually, a tube amp for the mids/highs and s/s for the woofer.

You can also bi-wire a stereo speaker, and on some, tri-wire. But this method has raised many discussions for pro/con on improving the sound.

What frequency does a low b go down to 25 hz or so? Seems like manufactures would build cabinets geared at say five string basses. The problem I see is that manufactures try to "cover all ranges" in their cabinets, and one size DOES NOT fit all.

 

[billfitzmaurice]

Bi-amping is used in pro-sound because crossing over at low frequencies with passive components isn't particularly practical, and bi-amping allows using two small amps instead of one big one. Home speakers generally don't bi-amp because they don't have to, although if your system is a 5.1 or better with a self-powered sub that is bi-amping, and is done for the same reasons as noted above.

What frequency does a low b go down to 25 hz or so? Seems like manufactures would build cabinets geared at say five string basses.

32Hz actually, but going that low isn't necessary, as the fundamental is at least 12dB lower in level than the second harmonic at 64 Hz.

 

[specplyrz]

"if your system is a 5.1 or better with a self-powered sub that is bi-amping, and is done for the same reasons as noted above."

Actuatly this is not true "bi-amping". All the indivudual speakers, center, left/right/front/rear are getting full range signals. The subwoofer, almost ALL, subwoofers are self amplified in a home system. The 5.1 or surround system, takes individual signals from the dvd and "sends" them to their proper places. The amplifiers used for these systems are typicaly 5 channel, FULL RANGE amps.

If I added a powered sub to a regular full range stereo system, I would no be bi-amping that system. I would just be adding a sub to it.

In the early days of surround, the rear channels were sent less signal, but newer movies and all the different settings that a 5.1, 6.1 or now 7.1 system has to offer, the rear and side fills are just as important as the center speaker, where you get about 70% of you movie information from.

 

[billfitzmaurice]

Actuatly this is not true "bi-amping". All the indivudual speakers, center, left/right/front/rear are getting full range signals.

A .1 receiver has a built-in electronic crossover that sends only LFE out via the sub output (that's what the .1 stands for) and only the bandwidth above that to the other speakers. That is bi-amping. Most receivers also have switchable high-pass filters on the sends to the LR/Center/Surround amps so that those speakers won't be overloaded with low frequency information.

 

[seamonkey]

...

32Hz actually, but going that low isn't necessary, as the fundamental is at least 12dB lower in level than the second harmonic at 64 Hz.

So for the signal oming from the bass, the fundamental is down 12db from the second harmonic? But wouldn't you not want your cabinet to roll this off more than what's coming out of the bass?

I know we don't need to hear the fundamental to know what it is, but it just seems like it's a personal preference to have it there. I know I look for cabs that at least list a usable low at the fundamentail I would play. I don't play with a low B though.

I like to try to duplicate what I hear on headphones with the amp/cabinet.

 

[specplyrz]

A .1 receiver has a built-in electronic crossover that sends only LFE out via the sub output (that's what the .1 stands for) and only the bandwidth above that to the other speakers. That is bi-amping. Most receivers also have switchable high-pass filters on the sends to the LR/Center/Surround amps so that those speakers won't be overloaded with low frequency information.

Not gonna argue with you on this....recievers while ecnomical, are not what I was refering to. I was refering to a seperate
component system. The kind of system that is used for stereo playback as well as surround. All that I have used/listened to, run full range to all speakers.

The sub is used for xtreem low enhancement. I have watched movies where the sub was never activated. All depends on the system.

 

[BassyBill]

Do you think that bi amping is still a good idea when using full range bass cabinets which seem to be the standard. From what I gather a full range cab is usually good at lows or highs or somewhere in between but not good at both ends of the spectrum?

Yes, it's a still a good idea in the exact sense you mention - "full-range" cabs are often (but perhaps not always) good at highs or lows, as you say. For this reason it makes sense to use different cabs for different sections of the frequency range. Bi-amping is one way of doing this.

 

[billfitzmaurice]

So for the signal oming from the bass, the fundamental is down 12db from the second harmonic? But wouldn't you not want your cabinet to roll this off more than what's coming out of the bass

In a perfect world yes, but the world isn't perfect. The size required of cabinets to achieve that is just too impractical for on stage use. But large PA systems with horn loaded subs can go flat to 32 Hz or even lower, and that's why they're able to give a depth of response through the PA that's simply unachievable with almost any backline bass cab.

we don't need to hear the fundamental to know what it is,

When you do hear a pure tone below 80 Hz you can't identify the note anyway; without harmonic content all you perceive is a noise with indeterminate pitch.

I have watched movies where the sub was never activated.

That's often the case with older movies that aren't encoded with LFE content, or really old films that had no content below 40Hz because few theatrical systems were capable of reaching that low before the mid '60s.

 

[specplyrz]

A .1 receiver has a built-in electronic crossover that sends only LFE out via the sub output (that's what the .1 stands for) and only the bandwidth above that to the other speakers. That is bi-amping. Most receivers also have switchable high-pass filters on the sends to the LR/Center/Surround amps so that those speakers won't be overloaded with low frequency information.

http://cgi.ebay.com/LIKE-NEW-CLASSE...FIER_W0QQitemZ5833568559QQcategoryZ14973QQssP

This is the kind of equiptment I am talking about. No worries about power here and speakers were Kef 104/2 and Martin Logans. Thank you for your informative and quick responses.

 

[theshadow2001]

Yes, it's a still a good idea in the exact sense you mention - "full-range" cabs are often (but perhaps not always) good at highs or lows, as you say. For this reason it makes sense to use different cabs for different sections of the frequency range. Bi-amping is one way of doing this.

Ok and what I gather is that some tens are better reproducing lows than some 15's and vice versa and if Im right then to the original idea of this thread of 10's vs 15's and how they compare is that it doesnt really matter.... It depends entirely on the cabinet as a whole not just the driver size. Its never straight forward is it?

 

[theshadow2001]

Then again why are subs on home systems PAs and the like always larger speakers than their full range counter parts. This whole thing is a head wrecker

 

[seamonkey]

Then again why are subs on home systems PAs and the like always larger speakers than their full range counter parts. This whole thing is a head wrecker

They're not on Bose systems.

Did I say that out loud?

 

[BassyBill]

Then again why are subs on home systems PAs and the like always larger speakers than their full range counter parts. This whole thing is a head wrecker

Relax, man... if your amp sounds good to you, it's the right one!

GENERALLY, larger drivers are better at lows than smaller ones. But you're right, it does depend on cab design, quality of components, etc etc. What is just plain wrong is saying that total speaker area is the only thing to consider and it doesn't matter which drivers you use to get it.

The best advice is still to try things until you find a set up that works for you. For me, I like a combination of 15s and 10s for bass. Other people are happy with different setups, such as all 10s, 12s, 15s or any combination. You pays your money...

 

[specplyrz]

Then again why are subs on home systems PAs and the like always larger speakers than their full range counter parts. This whole thing is a head wrecker

Actualy...most are not...the newer "cube" style subwoofers, started by Carver about 6-7 years ago, are 1foot cube..have tremendous output, (1200watt class d amp) for a ten inch woofer. I belive the total movement is 3 inchs!!! 1.5 forward, 1.5 rearward.

 

[billfitzmaurice]

My HT sub runs flat to 20Hz, is loaded with an 8 inch driver. It ain't the size of your pencil that counts, it's how you write your signature.

 

[theshadow2001]

Relax, man... if your amp sounds good to you, it's the right one!

GENERALLY, larger drivers are better at lows than smaller ones. But you're right, it does depend on cab design, quality of components, etc etc. What is just plain wrong is saying that total speaker area is the only thing to consider and it doesn't matter which drivers you use to get it.

The best advice is still to try things until you find a set up that works for you. For me, I like a combination of 15s and 10s for bass. Other people are happy with different setups, such as all 10s, 12s, 15s or any combination. You pays your money...

Unfortunately I dont have the option to try different speakers and combinations out. Well not the ones I'd like to anyways. Which is probably why Im trying to push for more science based answers but as usual the answer always ends up as try stuff out. Ah well its all good stuff to know.

 

[BassyBill]

Actualy...most are not...the newer "cube" style subwoofers, started by Carver about 6-7 years ago, are 1foot cube..have tremendous output, (1200watt class d amp) for a ten inch woofer. I belive the total movement is 3 inchs!!! 1.5 forward, 1.5 rearward.

But surely a 10" driver in these is a larger driver than the others in the system (in the other enclosures)?

I think "the shadow" was referring to driver size rather than enclosure. You can get great bass out of a small enclosure... but it needs, as you rightly point out, a hell of a lot of power. I remember back in the 70s when Videotone brought out the Minimax speakers. These were perhaps the first affordable compact hi-fi units to have really good low end, but, boy did they take some power to drive them well...