What is Sound Pressure Level?

[JBL 4645]

In the video! Well the topic mentioned amps of different class amplifiers A AB C and D and (T?) is that right? Where one amp is going positive and the other negative?

I just buy them and hock them up that’s all. So since an amp is needed for (sound pressure levels) what is best amp just simple link to thread on this site would suffice. And the amp has to be for £200.00 because I’m cheap bastard.

At around 24min Pass mentions the inefficiency issue of amps, he keeps Altec and even brought a pair JBL L300 recently. Pass isn’t on this site? He seems like a mellow relaxed chap. I mean cl.

[JBL 4645]

The video on youtube has locked-up again! 33m00s SIGH I give up, and I was just starting to enjoy the video conversation.

Edit: No hold on SIGH if I jog the video bar across the a bit the video continues but it keeps locking-up at 33m00s

[Rolf]

You don't know what you are talkin about ashley. What is your largets amp? in Watt (FTC)?

The video on youtube has locked-up again! 33m00s SIGH I give up, and I was just starting to enjoy the video conversation.

Edit: No hold on SIGH if I jog the video bar across the a bit the video continues but it keeps locking-up at 33m00s

[JBL 4645]

You don't know what you are talkin about ashley. What is your largets amp? in Watt (FTC)?

I don’t make the amps Rolf, I just buy the god damn things and wire them up.

I was thinking wow there’s so many different grades of amps out there. I don’t like tube amps because of the fragile glass tubes and I wouldn’t have one if one fell off the back of lorry for £10.00 pounds. I like transistors amps, just as someone else who doesn’t like transistor amps for maybe the same reasons?

There different breeds of amps out there made for different people with different tastes for different folks. Funny thing is we might be playing same LP or CD only on different amps and loudspeakers whether there JBL or other

[Rolf]

That is OK. BUT what is your amps rated? That was my question.

I don’t make the amps Rolf, I just buy the god damn things and wire them up.

I was thinking wow there’s so many different grades of amps out there. I don’t like tube amps because of the fragile glass tubes and I wouldn’t have one if one fell off the back of lorry for £10.00 pounds. I like transistors amps, just as someone else who doesn’t like transistor amps for maybe the same reasons?

There different breeds of amps out there made for different people with different tastes for different folks. Funny thing is we might be playing same LP or CD only on different amps and loudspeakers whether there JBL or other

[JBL 4645]

That is OK. BUT what is your amps rated? That was my question.

Mine are cheap brand and I’m not ashamed. Alesis RA300 Marantz 1030 and 1050

Brought as new for 2x and x1 brought used (2007) Alesis RA300 specs
http://www.alesis.com/ra300

Brought as second-hand (1990) x1 Marnatz 1030 specs
http://www.classic-audio.com/marantz/1030.html

Brought as second-hand (1990) x2 Marnatz 1050 specs
http://www.vintage-audio.com.ua/en/cat/336/1528.html

[Rolf]

Alesis 90W. Marantz 1030: ?? W. Marantz 1050: 30W.

These amps will clip at about 10-12W continius power, making the sound no good. You need larger amps.

Mine are cheap brand and I’m not ashamed. Alesis RA300 Marantz 1030 and 1050

Brought as new for 2x and x1 brought used (2007) Alesis RA300 specs
http://www.alesis.com/ra300

Brought as second-hand (1990) x1 Marnatz 1030 specs
http://www.classic-audio.com/marantz/1030.html

Brought as second-hand (1990) x2 Marnatz 1050 specs
http://www.vintage-audio.com.ua/en/cat/336/1528.html

[JBL 4645]

Alesis 90W. Marantz 1030: ?? W. Marantz 1050: 30W.

These amps will clip at about 10-12W continius power, making the sound no good. You need larger amps.

They’re used on a 4ohm load rated into 150watts so I should be safe with an 85db level of around 5watts at listening distance. If I push harder yes they’d be almost running on empty.

I’m going to revamp the amps sometime next year for control 1 and 5 with Behringer A500 for each LCR and later extra front channels, as well as for each stack of surrounds.

For the diy subs I’m looking at Behringer EP2000 which would be way than more than adequate.


If it makes you feel I’ve got light sound reinforcement power!

This track jams okay on the control series with some sub bass extension and I’m not grumbling if the lows can reach, (if I wanted it so) 110dbc 115dbc bat that would be too damn loud and I’ve had the SPL db metre reading 126dbc once, no thanks once was enough.

[Rolf]

Again: you have no idea what you are talking about. HI-Fi is for people who like music, and good sound. Do you even know what Hi-Fi means? It means "to get as close as possible to the real thing". Your equipment doesn't even are close to this, but I hope you are happy with the sound you have. 85db? have you ever been on a concert?

They’re used on a 4ohm load rated into 150watts so I should be safe with an 85db level of around 5watts at listening distance. If I push harder yes they’d be almost running on empty.

I’m going to revamp the amps sometime next year for control 1 and 5 with Behringer A500 for each LCR and later extra front channels, as well as for each stack of surrounds.

For the diy subs I’m looking at Behringer EP2000 which would be way than more than adequate.


If it makes you feel I’ve got light sound reinforcement power!

This track jams okay on the control series with some sub bass extension and I’m not grumbling if the lows can reach, (if I wanted it so) 110dbc 115dbc bat that would be too damn loud and I’ve had the SPL db metre reading 126dbc once, no thanks once was enough.

[JBL 4645]

Again: you have no idea what you are talking about. HI-Fi is for people who like music, and good sound. Do you even know what Hi-Fi means? It means "to get as close as possible to the real thing". Your equipment doesn't even are close to this, but I hope you are happy with the sound you have. 85db? have you ever been on a concert?

I don’t like PA concerts they suck because their TOO DAMN LOUD! It leads to hearing loss and I won’t go with 100 feet of one without ear plugs!

And Hi-Fi last time I checked means High Fidelity Hi-Fi for short. I’m glad you’re happy with those JBL 43?? and everyone else, please by all means knock yourselves out.

Have you even tried 85db its a damn site far lot comfortable than ear bashing 100db and you know the repercussions from hearing loss when played loud many times, over the years.

[Wayne]

Well the topic mentioned amps of different class Where one amp is going positive and the other negative?

Hi JBL 4645

The Amp your referring to is called a Push Pull Amplifier, it has to utilise 2 output transistors for each channel one amplifying the positive going signal & the other amplifying the negative going signal, it then uses a smaller transistor to stich the two back together before going to your speakers.

These are most common due to being very cost effective as opposed to a class A Amplifier which amplifies the whole signal through one transistor not two, requiring a much larger one along with larger heatsinks, power supply's etc.

Hope that helps explain a little.

Cheers wayne

[JBL 4645]

Hi JBL 4645

The Amp your referring to is called a Push Pull Amplifier, it has to utilise 2 output transistors for each channel one amplifying the positive going signal & the other amplifying the negative going signal, it then uses a smaller transistor to stich the two back together before going to your speakers.

These are most common due to being very cost effective as opposed to a class A Amplifier which amplifies the whole signal through one transistor not two, requiring a much larger one along with larger heatsinks, power supply's etc.

Hope that helps explain a little.

Cheers wayne

Wayne
Yeah kinder helps so the RA300 that I use have moderate size heat sinks on each side, what type is the Alesis RA300 I only buy them and wire them up and it breaks it breaks I’d send off for repair.

The Marantz1030/50 has a single heat sink in each amplifier.

So how fast how many milliseconds are these two (push and pull) circuits working? I guessing really fast?

[Wayne]

Wayne
Yeah kinder helps so the RA300 that I use have moderate size heat sinks on each side, what type is the Alesis RA300 I only buy them and wire them up and it breaks it breaks I’d send off for repair.

The Marantz1030/50 has a single heat sink in each amplifier.

So how fast how many milliseconds are these two (push and pull) circuits working? I guessing really fast?

The Alesis is a Push Pull Amp, being more powerfull than the Marantz it has to use larger Output Transistors & larger Heatsinks whereas the Marantz can handle the heat dissipated from its output transistors with just the one heatsink, its all about cost.

Dont know how fast this all happens, never really crossed my mind.

Cheers wayne.

[JBL 4645]

The Alesis is a Push Pull Amp, being more powerfull than the Marantz it has to use larger Output Transistors & larger Heatsinks whereas the Marantz can handle the heat dissipated from its output transistors with just the one heatsink, its all about cost.

Dont know how fast this all happens, never really crossed my mind.

Cheers wayne.

Wayne
Oh, cheers for that information that was most usual.

[Wayne]

Wayne
Oh, cheers for that information that was most usual.

Sorry bout my info being most usual, guess that comes when one becomes full of the obvious.

Cheers wayne.