DSP and the Single-Driver Speaker

[OzMikeH]

Originally posted by pjanda1
..........The only problem is that I've recently been working on a nice vinyl set up, and I really like it. I'd hate to have to run it through an A/D converter..........

pj

at 24 bit 192kHz in and out you could do it and preserve the full range of vinyl signals.. In fact you could do the RIAA thing in the digital domain too.

That will take a LOT of bandwidth and processor power to do it. It would be impossible with USB.
You could play the vinyl into the computer doing the riaa correction, then play the digital file afterward and do the EQ correction, this would reduce the processing load on the computer and firewire or usb or whatever interface you use.

An added benefit is your precious vinyl does not wear out or need to be cleaned more than once.

The high end cd player market will be in trouble soon. High end DACs are booming. It makes sense in many ways not to play cds directly.

For low noise: I run a cheap external USB dac on it's own linear power supply, not USB power. The fan in the Mac mini is almost silent, the hiss from my amp is louder (and it can run XP if you wish). The hard disks are at the other end of the house on a wireless connection.

[Bob Brines]

I just got throught with a demo in Dallas at the Lone Star Audio Fest. I used an HP Pavilion laptop with Vista Home Premium. The music was stored on a WD Passport (USB and virtually silent). The fan on the HP is so quiet that you have to hold the computer up to your ear to hear it. I also use an Internet radio station that streams jazz at 320k. I defy anyone to tell the differenc between a 320k MP3 stream and a CD unless they know the particular track intimately. (At home, the music is on the desktop in my office and wifi'ed to the laptop.)

I duct taped a 16' USB cable to the floor across the room to a diyParadise 'Monica' DAC, then to a 6BX7 P-P amp and then to my Lowther DX2 MLTL's. Results: Outstanding. I got comments like "What did you do to your Lowther's? They are so much smoother than last year!" What I did was take out the passive filters and set the EQ in the music player. Much more precise EQ than practical with a passive filter. In fact, I demo'd four different speakers and I had four different EQ's stored in the music player. And each was tailored to this specific room.

I had the opportunity to hear Brubeck's "Blue Rondo a la Turk" on a $20k pair of horns played from vinyl through God only know how many dollars worth of tubes. Warm, fuzzy, tubby and bloated. They sounded, well, horny! If fact, they sounded almost like that pair of PM2C's down the hall with old style whizzers mounted in "Medallions", only bigger. I went back to my room and played the same cut ripped from CD. Clear, precise and detailed. I have maybe $3k invested, and that includes the computer. Go figure.

Bob

[Scottmoose]

Sounds like those $20,000 jobs were either a duff design (I won't ask publically) or were suffering from a complete mismatch between amps & speakers, or lousy output transformers. If it's the former, then it's worrying if people are sucked in by it. If it's the latter, they should be ashamed of themselves for not ensuring a properly matched setup in advance. A good BLH shouldn't sound like that. But there aren't many of them of course.

Yeah, I've got a fair amount of music stashed in 320kbs mp3 on the computer for convenience & really, it's not far off redbook quality. Assuming it's been through a good encoder, & it's a well produced album, it'll beat a poor CD -redbook is increasingly suffering from overcompression, crippling its dynamic BW. Shame, as it really can sound very good indeed if done carefully. I still wish they'd implemented the discrete 4 channel facility built into it though. Computer audio increasingly looks like a way forward. I'm not going to stop buying CDs as I like their physical presence, but the Squeezebox is a dead certanty for this year now. Good to know that the DSP is a substantial step forward from the passive circuit. BTW -what was the jazz station you mentioned Bob?

[OzMikeH]

My current DAC is a bit harsh in the top end, I've been looking for another DAC. Monica appears to be exactly what I need so I've just ordered one. Thanks for the tip-off Bob.

I didn't realise you had a commercial interest in what you're doing, If I had known I wouldn't have asked you to share your EQ settings for the FE207E earlier. Sorry about that.

[rjbond3rd]

Originally posted by Scottmoose
...A good BLH shouldn't sound like that...

I heard the same room and they were going for that warmed-up slightly "tubby" sound, so I don't think it was a case of something being amiss. (Amp was similar to, or the same as, the attached image.)

I have to agree that Bob's setup was in many respects superior. The other speakers are a status symbol and while I can't afford them, I certainly don't mind if others wish to pay that much -- consider it the non-DIY tax.

[Scottmoose]

I see large pretty transformer covers. I wonder what they're hiding... Looks like 6c33 too, which isn't going to do it many favours either.

[chrisb]

Hey Bob - congrats on the response at Lone Star.

An open question to all - any suggestions for an iTunes plug-in with more comprehensive EQ facilities that the built-in? For recent converts or long-time Mac users, the thought of a dedicated Windoze PC for music seems a bit regressive.

time to duck and cover?...

[rjbond3rd]

Hi Scottmoose, slightly off-topic but on the topic of the flare, here's a pic of the underside of a model from the same company -- does this not look like a series of straight pipes except for the last fold?

(I was expecting smooth expansions a la Ron's horns.)

The pic is from: http://www.dagogo.com/MaxxHornImmersion.html

[Sjef]

within foobar you can also set the output to ASIO playback, this can be done with a free ASIO driver like ASIO4ALL. Now you can run a VST Host in wich you can run any VST eq plugin you like, the Unique-lizer is a good example for instance but here are also free plugins. This way you can run a parametric eq wich is much more accuarate to set the baffles step correction and kill some peaks in your system then it is possible with a 31band eq.

you can even run a multiple vst host and run as many plugins as you like including a crossover in case you have a multiple output soundcard/dac.

You can still go a step further and measure the whole system, create an inverse impulse response of it and run through a vst convolver and you will have a totally corrected speaker system. There a very comprehensive thread about all this called howto a pc crossover or something, can't remember.

Funny thing is that all of this can be done within your excisting computer without adding any hardware at all.

[chrisb]

Originally posted by Sjef
within foobar you can also set the output to ASIO playback, this can be done with a free ASIO driver like ASIO4ALL. Now you can run a VST Host in wich you can run any VST eq plugin you like, the Unique-lizer is a good example for instance but here are also free plugins. This way you can run a parametric eq wich is much more accuarate to set the baffles step correction and kill some peaks in your system then it is possible with a 31band eq.

you can even run a multiple vst host and run as many plugins as you like including a crossover in case you have a multiple output soundcard/dac.

You can still go a step further and measure the whole system, create an inverse impulse response of it and run through a vst convolver and you will have a totally corrected speaker system. There a very comprehensive thread about all this called howto a pc crossover or something, can't remember.

Funny thing is that all of this can be done within your excisting computer without adding any hardware at all.

Yes, all very interesting, and agreed that the 'puter as file server and front-end has lots of promise. However, as I queried above, is there anything for the iMac user who'd rather not run virtual Windows or Unix OS just to provide more comprehensive EQ (including multiple pre-sets) than the stock iTunes?