Indeed.
0/ DC300 run full range is an awful amplifier
1/ when has Gary ever not gone in and added his own magic?
dave
Yes, doubtless #1 or even #2 left unspoken, but it LOOKED stock. Only ran up to about 100 Hz for the subs. His all SS push pull Tabor with input splitter, interstage and output transformers involved, drives the mids and highs. After EnABL he dropped one of the Beta 8 drivers as redundant. A large, ribbon flat panel, tweeter sits on top of the U baffle that houses the Beta 8 driver. Not the prettiest system ever seen, but OMG effective.
Bud
Bud
I suspect that a quest to achieve "iron fist bass" through the use of one amplifier in preference to another means that either:
- the quest team have headed off in completely the wrong direction, or
- I have completely misnderstood what you are after.
Iron fisted bass to me is not a nuance, it is the smack around the head and physical kick in the guts that is delivered by a serious sound system capable of live music levels of SPL.
This is not that hard to do but:
- don't pretend that a domestic speaker will do this. In this I include all your vita, scan speak etc drivers
- don't try to do this with anything but an actively crossed system (ok I concede it might be possible full range into a passive crossover but I forecast dead tweeters)
- do consider the use of Pro drivers. Choose them carefully
- do recognise the need for balanced mid bass with sub.
This last bit is critical. All the sub in the world sounds crap if not balanced with midbass - especially in the 60-200hz region.
Don't get me wrong. I have a lot of (what may now be ageing) good quality domestic drivers, and in the "moderate" SPL domain they are brilliant.
The problem is that if you want to produce the viserial thrill of that hit on the drum or snapping bass line that cracks you around the ears and twists your guts, then you need the capacity to generate some serious short term SPL.
This is not what domestic drivers are made to do.
Do the math on a fairly efficient domestic driver and you will almost always find that short of overdriving it you cannot hope for more than 105 odd dB. This usually ignores compression and issues with excursion. If you try this on a full range amplifier it also ignores clipping and what this does to your tweeter.
If you are really after iron fisted bass I suggest you rethink the vifas and keep them in the same special place I do (for moderate listening where they really do shine).
If this is about something intangible that one amplifier will fix over another then I politely excuse myself lest I become heretical.
To me the basics are:
- active crossover. Minimum 2 way but prefer 3 way. Get the sub off the bassmid and highs
- a good high efficiency sub.
- 30 hz and up is a minimum. Go for something that can deliver toward 120 dB. This will however deliver all but the most extremely processed music. Below 30 hz is an option for those with lots of space.
- get some excellent bassmid and high drivers. These need to be capable of similar peaks, and be appropriately matched to the subs If you fail here the bass will sound crap.
- the crossover and matching is pretty important. I have done this in analogue active but I promise that a digital crossover will make this a whole lot easier.
Things this does:
- the drivers will be capable of 10 or more dB SPL
- the crossover will allow the amplifiers to drive only the voltage required in their band. If this sounds obtuse read up on active crossovers and why you would want one.
- the use of an active system means that if you do clip the subs a bit, this does not affect the midbass and highs. This is a super super important difference.
That extra 10 or 15 dB that this delivers makes a difference that is profound.
The clarity of sound you will achieve at solid SPL levels is surprising.
Phil
- the quest team have headed off in completely the wrong direction, or
- I have completely misnderstood what you are after.
Iron fisted bass to me is not a nuance, it is the smack around the head and physical kick in the guts that is delivered by a serious sound system capable of live music levels of SPL.
This is not that hard to do but:
- don't pretend that a domestic speaker will do this. In this I include all your vita, scan speak etc drivers
- don't try to do this with anything but an actively crossed system (ok I concede it might be possible full range into a passive crossover but I forecast dead tweeters)
- do consider the use of Pro drivers. Choose them carefully
- do recognise the need for balanced mid bass with sub.
This last bit is critical. All the sub in the world sounds crap if not balanced with midbass - especially in the 60-200hz region.
Don't get me wrong. I have a lot of (what may now be ageing) good quality domestic drivers, and in the "moderate" SPL domain they are brilliant.
The problem is that if you want to produce the viserial thrill of that hit on the drum or snapping bass line that cracks you around the ears and twists your guts, then you need the capacity to generate some serious short term SPL.
This is not what domestic drivers are made to do.
Do the math on a fairly efficient domestic driver and you will almost always find that short of overdriving it you cannot hope for more than 105 odd dB. This usually ignores compression and issues with excursion. If you try this on a full range amplifier it also ignores clipping and what this does to your tweeter.
If you are really after iron fisted bass I suggest you rethink the vifas and keep them in the same special place I do (for moderate listening where they really do shine).
If this is about something intangible that one amplifier will fix over another then I politely excuse myself lest I become heretical.
To me the basics are:
- active crossover. Minimum 2 way but prefer 3 way. Get the sub off the bassmid and highs
- a good high efficiency sub.
- 30 hz and up is a minimum. Go for something that can deliver toward 120 dB. This will however deliver all but the most extremely processed music. Below 30 hz is an option for those with lots of space.
- get some excellent bassmid and high drivers. These need to be capable of similar peaks, and be appropriately matched to the subs If you fail here the bass will sound crap.
- the crossover and matching is pretty important. I have done this in analogue active but I promise that a digital crossover will make this a whole lot easier.
Things this does:
- the drivers will be capable of 10 or more dB SPL
- the crossover will allow the amplifiers to drive only the voltage required in their band. If this sounds obtuse read up on active crossovers and why you would want one.
- the use of an active system means that if you do clip the subs a bit, this does not affect the midbass and highs. This is a super super important difference.
That extra 10 or 15 dB that this delivers makes a difference that is profound.
The clarity of sound you will achieve at solid SPL levels is surprising.
Phil
I find it hard to sit idly by when damping factor is being discussed with the brain in neutral! If we confine ourselves to the real part of complex impedances, damping factor is the ratio of the load resistance to the driving source resistance.
True believers in high damping factors seem to concede that the wiring resistance can degrade the situation and often have cables that could be used for arc welding.
What gets overlooked is that the voice coil resistance is also in the series loop. This means that the damping properties have already been defined by this dominant resistance, so it is pointless trying to remove the last few milliohms in the driving source (amplifier) or the cables.
I notice that Rod Elliott, who is a great debunker of audio myths has yet to latch on to this reality. Having said that I concede that I did learn from him that passive crossovers cause a loss of driver damping control at the band limits due to parallel resonant circuits in the driving loop. A good reason to avoid them.
Keith
True believers in high damping factors seem to concede that the wiring resistance can degrade the situation and often have cables that could be used for arc welding.
What gets overlooked is that the voice coil resistance is also in the series loop. This means that the damping properties have already been defined by this dominant resistance, so it is pointless trying to remove the last few milliohms in the driving source (amplifier) or the cables.
I notice that Rod Elliott, who is a great debunker of audio myths has yet to latch on to this reality. Having said that I concede that I did learn from him that passive crossovers cause a loss of driver damping control at the band limits due to parallel resonant circuits in the driving loop. A good reason to avoid them.
Keith
Yet full passive systems outstretch their full active counterparts by a country mile ..
This is becoming a funny thread , the OP ask what gives you tight bass from an amplifier , what does speaker brand , topology or xover used have to do with his amplifier question ...
I'm sure I'm guilty of this as well!
So, to make amends, here's a posting from last November made on another forum.
(I wrote: )
AK's Dave Newman (dnewma04) wrote:
"Let's do some math.
We know that damping factor is a ratio, specifically, it's the load impedance divided by the output impedance of the amplifier. For now, we'll ignore how amplifiers attain low output impedance just for the sake of simplicity.
So, let's say we have an amplifier with a damping factor of 2000 and an impedance of 8 ohms.
DF = Load Impedance / Output Impedance
2000 = 8 / Output Impedance
Output Impedance = .004
All is well in the world, right? We have our staggeringly high damping factor but we've ignored something important.
We forgot to include the series resistance of the speaker wire between the amp and speakers. Let's redo the calculation now.
Again, we know that DF = Load Impedance / Output Impedance, but now we are going to add in the effects of the speaker wire into our equation to figure out what the "real" or "effective" damping factor is of the real world situation. For simplicity sake, we'll err on the side of caution and say that it's very low resistance wire and only presents a .1 ohm load.
DF = 8 ohm / (.004 ohm + .100 ohm)
DF= 8 ohm / .104
DF= 76.9
The advertised damping factor of 2000 is now only 77 at the terminals of the speakers.
Now, let's look at what is going on at the terminals of the woofer in a speaker system with a passive crossover.
It's not unusual to have a series resistance of 1 ohm in a passive crossover, but just for a best case scenario, let's say that it's only .25 ohm.
DF = 8 / (.004 + .100 + .250)
DF = 8 / (.354)
DF = 22.6 at the woofer.
Now, let's say the damping factor of the amp is 20000! Surely that must make a huge difference being an order of magnitude higher than 2000!
Unfortunately, the reality is:
DF = 8 / (.0004 + .25 + .1)
DF = 22.8
It's essentially the same.
Now, let's say that the amplifier in the same scenario is only at 50.
DF = 8 / Output impedance
50 = 8 / Output Impedance
Output Impedance = .16
Now that we have the output impedance of the amp with a DF of 50, let's substitute into our scenario to see the DF at the woofer:
DF = 8 / (.16 + 1 + .25)
DF = 8 / (.51)
DF = 15.7
Do you see how most people just don't find DF that important? In the real world, the difference between a low DF amp and a ridiculously high DF amp is essentially moot at the woofer."
Best Regards,
TerryO
Last edited:
Hi,
There is absolutely nothing about the above arrangement that is
good for low bass, 20Hz with authority is a complete pipe dream.
rgds, sreten.
Maybe they are talking about a chilum pipe , nuff dreams from that one ...
If it arn't got a box and a well tuned vent with good box to speaker vent ratio fuuurgit about it ...
Last edited:
Hi,
Just look at it : two bass drivers loaded by a small common volume,
the central triangle. The rest of the cabinet does nothing at very low
frequencies but will resonate and boost output well above 100Hz.
(Only using them below 100Hz renders the arrangement pointless).
It just poor design if your interested in bass extension for a given
box volume. Same box volume but used as a box with drivers
mounted on opposite faces with a vent tuned to around 20Hz
is much better arrangement. Still need EQ but not as much.
rgds, sreten.
Hi, Nothing. I just can't take people stating something completely untrue. rgds, sreten.
The claim was "20Hz with astounding authority", the only outstanding thing is the BS level.
Last edited:
It's Gary Pimm. I wouldn't be very comfortable saying what you are saying. After Chris heard these things he came back with similar comments to Pano.
You far too often call BS without direct experience.
dave
Look, on paper DF above a certain point is meaningless.
Yet, when you *listen* to two different amps (let's limit ourselves to typical solid state amps so as to not get into areas that are best avoided) *usually* the bass character changes - especially when the speakers are pretty clean, and have good LF response.
If that doesn't happen for you, I don't know what to say.
The subs I built and designed back in 1980, they are on my website, do NOT need 120dB SPL to kick you in the gut. They kick you in the gut just fine, and do that at modest SPLs. They also move windows, or wood floors (not concrete ones). They launch a wave of "THUD" when it is in the recording.
Try Mickey Hart's Gates Of Dafos (title cut) to see what ur system is doing in that regard. It will show. Oddly enough I used to describe the effect heard as "someone dropping a safe on the floor of a stage". Or maybe a piano size thingie... what is interesting is that in the course of making a purchase of a TT from one of the main people at Reference Recordings, and i mentioned this to him. The surprise is when he said that this is *exactly* what Mickey Hart did! So go try it. If it doesn't really sound like something incredibly heavy is *really* getting dropped, ur bass section just ain't cuttin' the mustard!
@rhythmsandy - you have to compare the schematic of the standard Crown MacroTech with the MacroReference to see what they did for that particular amp. You can not get this sort of ultra high DF with powersupply mods, it's in the output section. Theirs uses a large quantity of bipolars in a floating bridge, plus the feedback. This lowers the output impedance to a stupid low quantity.
_-_-bear,
Yet, when you *listen* to two different amps (let's limit ourselves to typical solid state amps so as to not get into areas that are best avoided) *usually* the bass character changes - especially when the speakers are pretty clean, and have good LF response.
If that doesn't happen for you, I don't know what to say.
The subs I built and designed back in 1980, they are on my website, do NOT need 120dB SPL to kick you in the gut. They kick you in the gut just fine, and do that at modest SPLs. They also move windows, or wood floors (not concrete ones). They launch a wave of "THUD" when it is in the recording.
Try Mickey Hart's Gates Of Dafos (title cut) to see what ur system is doing in that regard. It will show. Oddly enough I used to describe the effect heard as "someone dropping a safe on the floor of a stage". Or maybe a piano size thingie... what is interesting is that in the course of making a purchase of a TT from one of the main people at Reference Recordings, and i mentioned this to him. The surprise is when he said that this is *exactly* what Mickey Hart did! So go try it. If it doesn't really sound like something incredibly heavy is *really* getting dropped, ur bass section just ain't cuttin' the mustard!
@rhythmsandy - you have to compare the schematic of the standard Crown MacroTech with the MacroReference to see what they did for that particular amp. You can not get this sort of ultra high DF with powersupply mods, it's in the output section. Theirs uses a large quantity of bipolars in a floating bridge, plus the feedback. This lowers the output impedance to a stupid low quantity.
_-_-bear,
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.