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Old 21st July 2013, 07:14 PM   #11
JetFire is offline JetFire  United States
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Quote:
Originally Posted by SpinMonster View Post
No you dont lose any mids.
How would it work with a stereo signal coming in to the amps (vocals, guitar)? I have an old receiver in my garage that's down to 1 channel and I "loose" voices and instruments sometimes.

Quote:
Originally Posted by SpinMonster View Post
Using a single 10 instead will play deeper than 8's and be the same size. Most tweeters are more efficient than an 8" so you are padding it down to match the lower spl of an 8 or 6.5 which wastes the available power. It just plays louder with a bigger speaker. At any real distance you are not hearing stereo from 2 8's and 2 tweeters so a single mono speaker that plays deeper will also play louder with the same power level.
The 10" woofers I saw needed big boxes or tons of power to get down below 40hz. I was only planning on using 1- 8" woofer paired with 2- 3" mids. The Dayton RS 8" needs 80w and around 1.1ft3 to get to 38hz.

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Originally Posted by SpinMonster View Post
Pro audio 10" speakers easily play high enough for a tweeter especially is you horn load it. By contrast, the RS dayton speakers are power hungry and wont get anywhere near the volume level.
I looked at the pro speakers a bit. Didn't see any that could get below 40hz, those still needed huge boxes to get close. A lot of the pro-drivers have really high RMS numbers. Honestly, I'm not hip to using this type of driver.
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Old 21st July 2013, 07:19 PM   #12
JetFire is offline JetFire  United States
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Originally Posted by jReave View Post
Yes. Cross around 400-1000Hz (I'm guessing) with the Vifa TC9, and use 2 in parallel, not for the stereo effect but to get the efficiency up to about 89dB. The amp has to be happy with a 4ohm load tho.

The price is right on this driver and it plays exceptionally cleanly.
I get the concept of paralleling the mids to bring up their efficiency.

Can you explain how or why I won't loose half of my stereo signal?
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Old 21st July 2013, 07:57 PM   #13
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I have an old receiver ... down to 1 channel and I "loose" voices and instruments sometimes.

That's because it is a Stereo amp with one channel missing, you are only getting half the signal.

(10" need) tons of power to get down below 40hz.

You really don't need to go below 40hz, especially in a system like this. This is not a pure fidelity system, this is just, according to you, background music for an outdoor gathering with a few friends. Don't become too obsessed with ultra-low frequency response. Remember many very good and very popular bookshelf speakers are in the low-50's to high-40's, and they sound very good.

There is a difference between perceived bass and depth of bass. I had some very small bookshelf speakers that were rated at 80hz on the low end, and despite that, they had very good perceived bass. This is typically accomplished by adding a slight bump to the bass response to emphasize that range. The range where you most perceive bass, the bass presence range, if in the roughly (best guess, but you can look it up) 50hz to 150hz range.

But you have to understand, that the smaller the speakers, the more localized the sound, especially outside. There is a reason they don't throw rock concerts with a pair of bookshelf speakers. The localization of sound is too your advantage, as it will not cause the neighbors to call the police.

Again, you need to think long and hard about how much space you need to cover, and how loud you need to go. If both of those factors are reasonably contained, then you can get buy with smaller speakers.


You also need to consider what you are going to use for amps for this system, and the source component of your sound. Likely if you are summing left and right channels into a mono low-bass channel, you will need three amps.

Also keep in mind that Dayton and others make Dual Voice Coil speakers. Though not intended for this, I'm told you can put one stereo channel on each voice coil, and the net result is a sum of the two channels creating, in effect, a combined mono channel.

Dayton Audio SD215A-88 8" DVC Subwoofer 295-484

Dayton Audio SD270A-88 10" DVC Subwoofer 295-486

More often the Dual Voice Coil are used to control the impedance of multiple speakers.

There are also transformers that are used in ceiling speakers that sum two channels together to make a mono channel. You might typically use something like this in a bathroom where you want music, but have limited space. Instead of two stereo speakers, you add one speaker with a summing transformer.

On the subject of amps, if you choose to build a complete Mono system, Dayton makes a Plate Amp that has a THREE channel mixer built into it, plus 150w of power to 8 ohms.

Dayton Audio PMA250 250W PA Module with Mixer 300-797

You could attach the amps to a 2-way speaker system with passive crossovers, and have something what would easily make an outdoor party. If you want expand in the future, simply add a second system for stereo. Plus you have additional channels should you need to add a microphone for what ever reason.

So, don't become so fixated on a the drivers that you forget you are building a System.

Just a few random thoughts.

Steve/bluewizard
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Old 21st July 2013, 08:59 PM   #14
jReave is offline jReave  Canada
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Quote:
Originally Posted by JetFire View Post
I get the concept of paralleling the mids to bring up their efficiency.

Can you explain how or why I won't loose half of my stereo signal?
Sorry, I was thinking in terms of a mono signal feeding the 2 drivers.
If only using 1 channel when running in stereo, then for sure you'll lose 1/2 the content.
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Old 21st July 2013, 10:26 PM   #15
JetFire is offline JetFire  United States
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Quote:
Originally Posted by BlueWizard View Post
That's because it is a Stereo amp with one channel missing, you are only getting half the signal.Steve/bluewizard
For example: Iphone to mini-jack, mini-jack direct to amp, out to single speaker without loss because I'm bridging each stereo channel?

Quote:
Originally Posted by BlueWizard View Post
You really don't need to go below 40hz, especially in a system like this. This is not a pure fidelity system, this is just, according to you, background music for an outdoor gathering with a few friends. Don't become too obsessed with ultra-low frequency response. Remember many very good and very popular bookshelf speakers are in the low-50's to high-40's, and they sound very good.

There is a difference between perceived bass and depth of bass. I had some very small bookshelf speakers that were rated at 80hz on the low end, and despite that, they had very good perceived bass. This is typically accomplished by adding a slight bump to the bass response to emphasize that range. The range where you most perceive bass, the bass presence range, if in the roughly (best guess, but you can look it up) 50hz to 150hz range.Steve/bluewizard
So if I can get down between 50hz and 150hz I'll be "sounding" low? I believe that. Continuing with that, if I go pro 10" driver and get down to 60hz vented......I'd be really happy?

Quote:
Originally Posted by BlueWizard View Post
But you have to understand, that the smaller the speakers, the more localized the sound, especially outside. There is a reason they don't throw rock concerts with a pair of bookshelf speakers. The localization of sound is too your advantage, as it will not cause the neighbors to call the police.

Again, you need to think long and hard about how much space you need to cover, and how loud you need to go. If both of those factors are reasonably contained, then you can get buy with smaller speakers.
I don't usually enjoy when others "share" their music with me, I'm on the localization side of things.

Quote:
Originally Posted by BlueWizard View Post
You also need to consider what you are going to use for amps for this system, and the source component of your sound. Likely if you are summing left and right channels into a mono low-bass channel, you will need three amps.

Also keep in mind that Dayton and others make Dual Voice Coil speakers. Though not intended for this, I'm told you can put one stereo channel on each voice coil, and the net result is a sum of the two channels creating, in effect, a combined mono channel.

Dayton Audio SD215A-88 8" DVC Subwoofer 295-484

Dayton Audio SD270A-88 10" DVC Subwoofer 295-486

More often the Dual Voice Coil are used to control the impedance of multiple speakers.

There are also transformers that are used in ceiling speakers that sum two channels together to make a mono channel. You might typically use something like this in a bathroom where you want music, but have limited space. Instead of two stereo speakers, you add one speaker with a summing transformer.

On the subject of amps, if you choose to build a complete Mono system, Dayton makes a Plate Amp that has a THREE channel mixer built into it, plus 150w of power to 8 ohms.

Dayton Audio PMA250 250W PA Module with Mixer 300-797

You could attach the amps to a 2-way speaker system with passive crossovers, and have something what would easily make an outdoor party. If you want expand in the future, simply add a second system for stereo. Plus you have additional channels should you need to add a microphone for what ever reason.

So, don't become so fixated on a the drivers that you forget you are building a System.

Just a few random thoughts.

Steve/bluewizard
I love the PA Module with the mic input! Not understanding the power side of this equation yet, I'm wondering about powering it. The amplification for this project has been bugging me. I thought I needed to pick drivers first and try to match amplifiers accordingly.

Current thoughts:
Open to other options. Could I pull off a good coverage with one 10" and one tweet/mid?
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Old 21st July 2013, 10:27 PM   #16
JetFire is offline JetFire  United States
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Quote:
Originally Posted by jReave View Post
Sorry, I was thinking in terms of a mono signal feeding the 2 drivers.
If only using 1 channel when running in stereo, then for sure you'll lose 1/2 the content.
Copy, thanks.
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Old 23rd July 2013, 06:11 PM   #17
JetFire is offline JetFire  United States
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Bump
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Old 23rd July 2013, 10:04 PM   #18
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You do understand that the PA Module I link to is also a 150w to 8 ohm Power Amp. So, Power Amp and Mixer all in one.

There are other options. This one doesn't have a lot of power, but if you are not trying to full the great outdoors, it might be fine. This is a 2.1 Plate Amp, so Stereo in, 2 channels plus Subwoofer out -

Dayton Audio MCA2250E 2.1 Channel Class D Amplifier 300-771

So, I think at this point, if you want more responses, you need to Re-Think and Re-State your goals.

Keep in mind you can get a couple of Active PA speaker boxes with 6" or 8" bass drivers that could be connected directly to an iPod or MP3 player or similar, and they would be fine. Especially given that you are not trying to throw a rock concert.

One problem is going to be the need for battery power. That complicates matters when buying off-the-shelf. If you build your own, that is you use amp modules like these -

4x100W @ 4 Ohm TK2050 Class-T Digital Audio Amplifier Board 320-302

2x100W @ 4 Ohm TK2050 Class-D Audio Amplifier Board Only 320-334

They use from 10v up to 30v with a 32v max. The more voltage the more power. But the more power, the greater the current draw and the shorter the battery life. This are the trade-offs and compromises you must consider.

I would suggest using Motorcycle batteries as they are sealed and compact. Though they are not cheap.

https://www.google.com/search?hl=en&....2.j6kooZEK-1Q

As an alternate, there are 12v jump starter boxes that are reasonably cheap, compacted contained, easy to recharge.


https://www.google.com/search?hl=en&....1.9TJqs7CbIJ4

You determine the battery life by calculating Amp/Hours. Get a sense of the current draw, then you can determine how much time you can draw that current from the source supply.

So, you need a compact (moderately so) Single Box for playing music out doors. It would be best if it could be run both off AC or DC, though you only mention DC. It should have reasonably large drivers, though not necessarily huge, meaning 8" to 10" max.

So, it must have internal amps.

Do, does it need to be Stereo, or would stereo mixed down to Mono be good enough?

One simply solution might be a Car Audio Radio/CD/iPod. That will certainly run easily off 12v, and should be easy to mount in the box.

Then the speakers, I think you are complicating the design by wanting a Subwoofer. Simply build two full range speaker in to the box, put the battery pack and amp in the middle between the speakers. Add some wheels if that appeals to you. Done!

The answer can never be better than the question. So, I suggest give the discussion so far, you re-evaluate what it is you want and need, then clearly list the goals, give us a working budget. Once you've laid that all out. Ask the question you need to ask to accomplish your stated goals.

Steve/bluewizard
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Old 24th July 2013, 07:14 AM   #19
JetFire is offline JetFire  United States
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Quote:
Originally Posted by BlueWizard View Post
There are other options. This one doesn't have a lot of power, but if you are not trying to full the great outdoors, it might be fine. This is a 2.1 Plate Amp, so Stereo in, 2 channels plus Subwoofer out -

Dayton Audio MCA2250E 2.1 Channel Class D Amplifier 300-771
I think that would be plenty for my first attempt. Could I power using this: Duracell 813-0207 or similar connected to a battery? Would I still need a XO for the full-rangers?

Quote:
Originally Posted by BlueWizard View Post
So, I think at this point, if you want more responses, you need to Re-Think and Re-State your goals.
Will do, I'll be entering the re-think stage.

Quote:
Originally Posted by BlueWizard View Post
You determine the battery life by calculating Amp/Hours. Get a sense of the current draw, then you can determine how much time you can draw that current from the source supply.

So, you need a compact (moderately so) Single Box for playing music out doors. It would be best if it could be run both off AC or DC, though you only mention DC. It should have reasonably large drivers, though not necessarily huge, meaning 8" to 10" max.
For example: The Dayton 2.1 amp you recommended looks like it draws 2amps....not sure? If I use 2- 7 Ah batteries in parallel or 1- 22Ah beast, the amp will run for how many hours through the inverter?

Quote:
Originally Posted by BlueWizard View Post
Then the speakers, I think you are complicating the design by wanting a Subwoofer. Simply build two full range speaker in to the box, put the battery pack and amp in the middle between the speakers. Add some wheels if that appeals to you. Done!

The answer can never be better than the question. So, I suggest give the discussion so far, you re-evaluate what it is you want and need, then clearly list the goals, give us a working budget. Once you've laid that all out. Ask the question you need to ask to accomplish your stated goals.
Thanks for the help and advice, much appreciated! If I get some longevity out of the Dayton 2.1 on batteries, I may keep the sub idea.
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Old 24th July 2013, 08:17 AM   #20
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If the amps draws 2 amps, then two 7A/h batteries will run it approximately 14/2 = 7 hours.

A single 22 A/h will run it for 22/2 = 11 hours.

If you have a DC to AC converter, then I'm sure you could run the Dayton 2.1. Bearing in mind that even at relatively high levels you are rarely averaging over about 3 watts. I've tested my amps at about 60% or 1 o'clock to 2 o'clock on the volume dial, and which is about the absolute loudest I would ever go, and the average power was about 2 watts. Keep in mind PEAKS were jumping up very high, but the long term average was very small.

If you insist on a 2.1 system, and you are not trying to throw a rock concert, then this might work off a DC to AC power station. Again, I just don't have enough information to tell.

Also, the Dayton 2.1 are Class-D or Digital amps, very efficient, very little wasted power.

The 2.1 amp has a variable crossover on the Subwoofer between 40hz and 240hz. But you can make the system a bit more efficient by cutting the Bass from the front or full range speakers. I'm not sure what I would do but as a suggestion, a 6db crossover on the full range of 240hz, which means Sub to the max also at 240hz, would not be amiss.

That would also increase the power handling and lower the distortion on the Full Range speakers considerably.

The Dayton 2.1 is only 25w on the front channels, but given that the front channels do not have to carry deep bass, that should be plenty of power. Again, especially so if you are not trying to throw a Rock concert.

I can only give you my opinion, the final decision is up to you. I've laid out the concept, you have to work out the details.

But consider this, how long can a car radio play off the car battery. A very very long time. Though your power source will be considerably smaller, I think it will be sufficient for a picnic or afternoon outdoors. For an all-day all-night party though, it might run short on power.

Dayton makes some 3" and 4" Reference full range speakers, though they are not cheap. They come in 4 ohms and 8 ohm, for you, I would suggest 8 ohm.

dayton reference full range - Parts Express Ships Fast and Ships Free

The 4" have a low end of 90hz and the 3" have a low end of 160hz. Again, if you add high pass crossovers to the Full Range at 240hz, that should work OK, and should make blending with the Subwoofer very easy.

Just a few thoughts.

Steve/bluewizard

Last edited by BlueWizard; 24th July 2013 at 08:21 AM.
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