Dual FRs but one is a 0.5 for baffle step?

[18Hurts]

Good day, all

Still pondering my near field desk top monitors and would prefer to try out full range speakers this time. They will be driven by a Topping USB DAC chip amp which has 15 watts at 4 ohms and around 10 at 8 ohms. Wrangled with getting bass and 4 ohms out of full ranges and remembered my center channels--they use the "0.5 baffle step correction" additional woofers set at 540 Hz. The 2.5 way system works very well.

I'm eager for near field full ranges but the "shout" or rising response typical of such devices slows me down. Then I realized I can use two 8 ohm full ranges and throw an inductor with a -3dB down point at around 400 Hz. This will drop the impedance down to around 4 ohms to get more (bass) power out of the T-amp, perform baffle step and have more air movement and volume for the 8" passive radiator. (box must have no port holes for outdoor use with iPods etc) The TBs have a rising response at the treble end and not very strong bass, I might get the bass to match the treble that way?

The 0.5 FR would solve my wish for lowered impedance, improved bass response, baffle step correction and lower distortion and with two FRs sharing the staggering 15 watts--it should be more durable for accidental stupid stuff.
The box won't be too large for a small desk (at least to me ) and I should hit 100 dB at the seated position which is enough.

http://www.tb-speaker.com/detail/1208_03/w5-1611sa.htm

My initial thought of the two TB W5-1611SA with one filtered at around 400 to 500 Hz and running passive radiators. My wish is to tune the PR to around 45 Hz since two TBs should not bottom out at 7.5 watts max each.

Has anyone tried the 0.5 dual FR for BSC, should anyone try it or is there issues I have not thought of? I really, really, REALLY like my 2.5 way center channel as the 4 woofers switch to 2 then XO to the tweet at 1.8 KHz. Just wondering if I am waaaaaay off base here... thanks for any suggestions be it alignments or psycho-active scripts I need to pursue.

[sreten]

Hi,

All makes sense but those drivers are not cheap. I don't believe the FR
for a second and off axis treble is going to be terrible with 5" FR's.

They seem overkill for 15W/channel but whatever floats your boat.

IMO 3" drivers are the largest size you can go before using a tweeter
is a good idea, but they'll get nowhere the efficiency of the above.

rgds, sreten.

[blakkshepeaudio]

You could always apply some line level EQ on the input to your amp to tailor the overall system response. Cheaper. Probably.

[planet10]

Nothing wrong with the idea of a 1.5 way. I don't know that this application is suitable for one. You are likely going to find that the BSC given is quite elevated vrs what you need.

I do note that the current price hasn't yet skyrocketed as much as the neo in them would suggest. The 1611 is a nice driver (we were considering doing them, i have a test pair, but the whole neo thing scared us away).

For your ap i'd suggest quality over quantity -- for your budget you could afford a set of Alpair10 and take some change away.

dave

[18Hurts]

Originally Posted by planet10

Nothing wrong with the idea of a 1.5 way. I don't know that this application is suitable for one. You are likely going to find that the BSC given is quite elevated vrs what you need.

I do note that the current price hasn't yet skyrocketed as much as the neo in them would suggest. The 1611 is a nice driver (we were considering doing them, i have a test pair, but the whole neo thing scared us away).

For your ap i'd suggest quality over quantity -- for your budget you could afford a set of Alpair10 and take some change away.

dave

Thanks Dave,
I really like the response of the Mark Audio FRs, the efficiency is low and the Alpair 10 is below 85dB from 800 Hz to 5 KHz. That would give me about 95dB max at 8 ohms from a T-amp. No worries about BSC since it is "built-in" and the treble rise would help with off-axis response.

The design is not just for me, it will be evaluated by friends and family for their use. 15 watts at 4 ohms and 10 watts at 8 ohms does not leave a lot of wiggle room. It is the ultimate "plug and play" high quality audio amp that is very simple to setup to any computer and allows MP3 player/phone connections.

My hope is FR speakers dump the Neo, goes to ceramic and gets the price down to 2009 levels. Once the price hits $300+ (including the $120 T-amp)...my buddies won't pay that much for "computer speakers" and I won't blame them. Get the Behringer $359 a pair bi-amped monitors, a USB sound card and go!

It is good to know that 1.5 way is an option, maybe a decent 4 or 5" FR will appear with 90dB efficiency and ceramic magnets so using 4 of them won't push it into Behringer/USB sound card territory.

[planet10]

I guess you need them to play REAL loud, 95 dB is well into hearing damage.

I haven't measured the 1611 yet so can't say what the efficiency is, A10 typically measures just over 86 dB.

I will say that there is a tendency to play music at lower levels if the speaker has better DDR. As well, capability on peaks is more a function of instantaneus power into the reactive load, and how well behaved it is when it goes into clipping. Not anything you will find on a spec sheet.

dave

[Cal Weldon]

How about running them FR but with one on the back or side? You will get the baffle step effect and it might make the imaging interesting as it did for the Calhoun.

[alspe]

Remember that power times 1,5 ( 10 --> 15 W) rises SPL around 2 dB's which is same amount when you move speaker closer to you or speaker closer to wall for free gain for bass.

1,5 way with full BSC could be too bass heavy for desktop use (gain from table etc)

[sreten]

Originally Posted by Cal Weldon

How about running them FR but with one on the back or side? You will get the baffle step effect and it might make the imaging interesting as it did for the Calhoun.

Originally Posted by 18Hurts

Thanks Dave,

..... it will be evaluated by friends and family for their use. 15 watts
at 4 ohms and 10 watts at 8 ohms does not leave a lot of wiggle room.
It is the ultimate "plug and play" high quality audio amp that is very simple
to setup to any computer and allows MP3 player/phone connections.

My hope is FR speakers dump the Neo, goes to ceramic and gets the price down to 2009 levels. Once the price hits $300+ (including the $120 T-amp)...my buddies won't pay that much for "computer speakers" and I won't blame them. Get the Behringer $359 a pair bi-amped monitors, a USB sound card and go!

Hi,

Your friends probably won't care about the design philosophy used either.
10W/15W is not a lot to play with, but in my 20's a 12W per channel amp
was adequate far field with a pair of 86/87dB speakers, not parties.

I think you can source a T-amp + supply for a a lot less than $120,
e.g.the bargain bucket Lepai has phono and 3.5mm inputs, and quite
usefully bass and treble controls, it can be improved, see other posts.

A very good small speaker to go with it might be the reduced BSC option of :
Zaph|Audio - 4" Bargain Mini , careful driver mounting is needed.
(and uses some tights material or similar when mounting the tweeter,
to protect the dome, otherwise it will inevitably get poked in.)

FWIW my nearfield computer speakers are "only" 2.5W per channel,
2.5" FR and 3" ABR, brilliant for the price, nearfield only, but having
said that they outperform many TV built in speakers farfield, see :
Computer Speakers - what you can get for 25 USD or 15GBP

I've also played around with :
http://www.amazon.com/Logitech-S220-...9369432&sr=8-1
These will go louder and do better bass and TBH once set up carefully,
(sub level needs matching to the mains and bass adjusted for no boom),
(also IMO placed centrally behind the monitor, sideways against the wall).
TBH would cover 90% of peoples expectations for a nearfield computer
system being "good", and a lot of peoples expectations of TV sound.

Neither will be nowhere near as good as the Lepai + ZBM4, but they
are in an entirely different price bracket, and the latter would be far
more critical of MP3 sound files and poorer quality laptop PC outputs.

I'm all for converting people to better quality stuff, but $300 seems
a steep entry point for a computer nearfield system, the latter
suggestions are about improving general computer audio
not critical music listening, where they do just OK.

rgds, sreten.

[borispm]

If Alpair's too expensive, try CHR70. I've recently got a pair of those and they sound brillant, and they're much more affordable, too. You may need very slight amount of BSC, and if you really need high SPL, I guess using a pair per channel isn't going to kill the budget as well. A pair will cost roughly as much as a single TB W5.
Simply build a BSC compensation and run a pair in parallel in each channel and you'll get yourself some pretty good sound.