Technology Student Wanting To Build Full Range System

[OzMikeH]

Forget watts. Do a bit of searching abour driver efficiency, and get a handle on how Decibels work. The MOST important thing when asking "how loud" is driver efficiency.
I have felt the bass in my chest from a one watt amplifier driving 103 dB/W speakers. Those could be listened to at normal levels directly connected to the headphones socket on an MP3 player powered from a single AAA battery. no amplifier. Once you start getting over about 97dB/W the price starts increasing exponentially.

Most domestic consumer three way speakers are 85 dB/w, they need ten times the amplifier power to make the same volume as 95 dB/W speakers. And yes, 95 dB/W speakers are pretty awesome on a 50 watt amp.

[Scottmoose]

Re watts: forget them, as Mike said (& I've mentioned a couple of times). I know it's easy to get fixated on them, but the figures are only maximum power handling, i.e. how much power the driver will theoretically take before it self-destructs. In reality, you'd never, ever get close to putting even a tenth of that figure into them in the real world. The Trend should handle the Monacors fine, even though they're not the most sensitive FR units on the planet. Which reminds me, I need to buy one myself.

Yes, it's impressive what you can do with a single unit, if you're willing to go larger than is common nowadays. For the BIB, you need to stuff the point above the driver, and put a nice layer of the same material (about an inch) on the base of the cabinet. That's about it really. BTW -Terry used 1in thick material in his drawing at the bottom of the page I linked to, so you need to keep that in mind when building out of 3/4in material. The sloping internal baffle will end 5.875in from the floor and the front & rear walls, not the 5.5in in the original diagram.

[G.Kennedy]

Firstly , Welcome, Secondly .... listen to everything they are saying. I did, and I have a great system, with plenty of bass and overall volume.

I built a set of BIB's using Fostex FE168eSigmas, a bit pricy at $145(us) per driver. And I built my cabinets with Baltic Burch at $80(us) per sheet. So really I have about $500 into the speakers. You can go cheaper .... but this is an unbelievable combo.

As for amps, I have been running them with a 2watt tube amp for the last few months and never have turned it all the way up. The drivers are 94.5db efficient. My tube amp is having some issues this week, so I am currently running them off the $30 Sonic Impact T-amp. It is great. Maybe lacking a bit of bass. But for $30 it can not be beat.

If you can make a budget of $700(us) .... build BIB's using 168e sigmas and a SI Super t-amp ... you are well on your way to a system that will not need upgrading soon.

[planet10]

Originally posted by morfius
Does the treands have enough power for the two monacors which will peak together at 120W? [/B]

For home hifi purposes we mostly ignore the power ratings. The question is, "will the speakers play load enuff". A small T-amp with its nominal 6W into 8 ohms puts it right into the same power class as a lot of the SE tube amps these were all designed to accomodate.

At typical "normal" listening levels we are using only milliwatts, so unless you are a headbanger then with Trends (or its ilk) should do a good job of getting you started.

Keep in mind that of late, we seem to be estalishing that (as a crude generalization) amplifier quality is inversely proportional to amplifier quality.

And further, the most cost effective method to get a system to play louder (assumming box size is not an issue) is to build more efficient speakers, not run out and get a bigger amplifier.

dave

[planet10]

Originally posted by Scottmoose
before it self-destructs. In reality, you'd never, ever get close to putting even a tenth of that figure into them in the real world.

Most causes of driver failure are caused by an amplifier "accident" -- due usually to amplifier failure or doing something boneheaded*. A big DC surge goes out the amp into the voice coil and almost instantly fueses the wire in it,

*(and more likely to happen with DC coupled amplifiers).

dave

[peterbrorsson]

Hi!
Scott, I believe you have tested the Monacors with 6 tube watts, or?
I have a feeling that the Monacors are hungry. I have only tested them with my Naim 30w and NAD 20w. This comparison is not fair but the Naim had better grunt.

Cheers
Peter

[morfius]

Originally posted by OzMikeH
Forget watts. Do a bit of searching abour driver efficiency, and get a handle on how Decibels work. The MOST important thing when asking "how loud" is driver efficiency.
I have felt the bass in my chest from a one watt amplifier driving 103 dB/W speakers. Those could be listened to at normal levels directly connected to the headphones socket on an MP3 player powered from a single AAA battery. no amplifier. Once you start getting over about 97dB/W the price starts increasing exponentially.

Most domestic consumer three way speakers are 85 dB/w, they need ten times the amplifier power to make the same volume as 95 dB/W speakers. And yes, 95 dB/W speakers are pretty awesome on a 50 watt amp.

Thanks for the explanation, it's incredible how efficient some speakers can be.

Originally posted by Scottmoose
Re watts: forget them, as Mike said (& I've mentioned a couple of times). I know it's easy to get fixated on them, but the figures are only maximum power handling, i.e. how much power the driver will theoretically take before it self-destructs. In reality, you'd never, ever get close to putting even a tenth of that figure into them in the real world. The Trend should handle the Monacors fine, even though they're not the most sensitive FR units on the planet. Which reminds me, I need to buy one myself.

Yes, it's impressive what you can do with a single unit, if you're willing to go larger than is common nowadays. For the BIB, you need to stuff the point above the driver, and put a nice layer of the same material (about an inch) on the base of the cabinet. That's about it really. BTW -Terry used 1in thick material in his drawing at the bottom of the page I linked to, so you need to keep that in mind when building out of 3/4in material. The sloping internal baffle will end 5.875in from the floor and the front & rear walls, not the 5.5in in the original diagram.

Are you referring to the diagram at the bottom of this page?: http://melhuish.org/audio/DIYTQ8.html

Is there a larger version of it as I can't make out the figures.

Originally posted by G.Kennedy
Firstly , Welcome, Secondly .... listen to everything they are saying. I did, and I have a great system, with plenty of bass and overall volume.

I built a set of BIB's using Fostex FE168eSigmas, a bit pricy at $145(us) per driver. And I built my cabinets with Baltic Burch at $80(us) per sheet. So really I have about $500 into the speakers. You can go cheaper .... but this is an unbelievable combo.

As for amps, I have been running them with a 2watt tube amp for the last few months and never have turned it all the way up. The drivers are 94.5db efficient. My tube amp is having some issues this week, so I am currently running them off the $30 Sonic Impact T-amp. It is great. Maybe lacking a bit of bass. But for $30 it can not be beat.

If you can make a budget of $700(us) .... build BIB's using 168e sigmas and a SI Super t-amp ... you are well on your way to a system that will not need upgrading soon.

Thanks for the reply, I think $700 is quite a jump from my budget.

I'll probably stick with some nice thick, cheap MDF and possibly veneer or paint it.

Originally posted by planet10


For home hifi purposes we mostly ignore the power ratings. The question is, "will the speakers play load enuff". A small T-amp with its nominal 6W into 8 ohms puts it right into the same power class as a lot of the SE tube amps these were all designed to accomodate.

At typical "normal" listening levels we are using only milliwatts, so unless you are a headbanger then with Trends (or its ilk) should do a good job of getting you started.

Keep in mind that of late, we seem to be estalishing that (as a crude generalization) amplifier quality is inversely proportional to amplifier quality.

And further, the most cost effective method to get a system to play louder (assumming box size is not an issue) is to build more efficient speakers, not run out and get a bigger amplifier.

dave

Thank you for the reply, once again I am amazed at the efficiency of speakers, I didn't realise how little power they required!

[morfius]

Forget about what I said, I just realised that the speaker box dimensions are typed out above.

[Scottmoose]

I'm not surprised the Naim had better grunt than the NAD. They both pump similar current (I assume the NAD is a 3020?) but Naim amps are renowned for their explosive bass. I'd be a bit put out if it turned out worse.

Yeah, the Monacors do need a few more watts than, say, a 166, but we're on an extremely tight budget & this is about the best I can come up with. The Fostex units that fall in budget are too small to do the bass, and there isn't really anything else that I know of better than the Monacors for this sort of money. They should do OK with a good T-amp.

[morfius]

If necessary, I could spend a bit more on the speakers