Speakers

[tyerkey]

Does anyone have recommendations about what speakers or drivers would go well with the low wattage Bottlehead amplifiers?  I am especially interested in diy speakers.  Thanks!

[porcupunctis]

I'm using Fostex 166e's in a back loaded horn with a SEX amp in a fairly small listening room.  Overall, this is a fairly inexpensive set up with really awesome sound.  It took a while for the speakers to break in but I'm blown away every time I sit down to listen.

I have a set of open baffle manifold subs in the ceiling for bass augmentation but even without those the sound is truly awesome.  I've listened to a lot of systems but Doc and Paul got a line on the good stuff here. 

Just about any high-efficiency top quality speakers will blow you away.  I hooked up some vintage Kenwood KL-7080's and couldn't believe what I heard. 

Hook 'em up and rock on!

[rewind67]

For DIY, you might want to look into Pi speakers. High-sensitivity and cost-efficient DIY kits ranging from 2-way BR's to corner horns. I run the Pi 2's with my S.E.X. and really like the combination.

If you are looking into the S.E.X. there is also the Bottlehead SEXy design using pre-finished Parts Express cabs; a clever full-range + subs concept at a totally reasonable cost.

There are also any number of full-range designs that could work for you; diyaudio.com and planet10 (http://www.planet10-hifi.com/) are a good resource for DIY.

Back-loaded horns are also something to look at. The above sites can help with that. Madisound also has flat-pack Fostex-based kits if your woodworking options are limited.

A lot depends on which Bottlehead amp you are interested in, your music preferences, and listening levels. If you can give some details that could guide suggestions.

Chris

[Paul Joppa]

For flea-power SET amplifiers, you need high efficiency speakers to get loud enough, if you are a typical audiophile or attentive listener. Efficiency is usually rated in terms of sensitivity, in decibels at 1 meter distance and at the "voltage input to the speaker that would produce one watt if the impedance were equal to the rated impedance". That whole rigamarole just reflects the fact that speaker impedance fluctuates over a wide range as a function of frequency. Typical minimum sensitivity is 93dB for 8 watts (300B), 96dB for 4 watts (2A3), and 99dB for 2 watts (45, and the SEX amp). There are various considerations that put a +/-5dB range on all these numbers - listening preferences and room acoustics being the main ones.

I bring up the impedance issue because zero-feedback amps have a low damping factor (most SETs are in the range of 2 to 3), and an uneven impedance results in a frequency response that changes if the damping factor is low. This is the second important criterion for a suitable speaker. It is usually said that a relatively flat and smooth impedance across the frequency range marks a SET-friendly speaker. There are however a few speakers that may have an uneven impedance but are designed to work best with SETs. Impedance dips are usually more of a problem than impedance peaks, for what it's worth.

Back to efficiency - the biggest factor is that there are no dome tweeters which are high efficiency, and a large majority of commercially available speakers use dome tweeters. That leaves three options:

1) horn tweeters - classic Altec, JBL, and Klipsch designs are popular, as are the Pi speakers which fall into this category

2) exotic tweeters - some ribbons, pleated diaphragms, and the like - Doc B's high resolution system uses the Raal ribbon for example

3) "full-range" drivers, which have enough extended treble to do without tweeters - Fostex and Lowther are the big names here. Mostly these are no more than 8" diameter drivers, and they have limited excursion, so they usually need some help to make decent bass. Horn loading on the back of the diaphragm, and subwoofers for more conventional cabinets are the usual approaches.

[Pfenning]

I have the Paramour amps with Pi 4 speakers. Mine use Eminance components and I like them a lot. I listen to rock and blues mainly and they will get really loud on 3.5 watts. I added subs to get the lower end fill I wanted, it's a big speaker, but still not quite full range in my opinion. I had the Fostex FE206 in a BR cabinet. It wasn't the optimum cabinet, backloaded horn I think would be better, but the they just weren't for me. They could sound really nice with the right music, but struggled with the music I listen to. As one of the guys mentioned, give some more details about your amp, room size, music preference and levels you typically listen at. Good luck.

Pfenning

[tyerkey]

Hi All,

I thank everyone for the input.  I see I have not made things as clear as I should have to start.  I am trying the quickie preamp because my 25 year old Rotel pre died.  I tried to fix it myself, and I learned about how to burn pc board.  The rest of my system includes a 40 watt Rotel amp RB870, Mirage 490 speakers, a Nakamichi CD4, and my Ipod.  I plan to add a squeezebox as soon as I get my system up and running.  So, why am I building instead of buying?  I like making stuff.  I also bought a few new boats for orthapedists when my wife crashed her motorcycle this summer, so spare cash is scarce.  Additionally, I like the sound of vintage 2 channel stereo equipment, and it's hard to find retail stuff I like that I can afford.  I am a guitar player and only play through tube amps.  The amps I love are ptp wired.  So when I saw the Bottlehead stuff, I decided it would be worth a try to see if I like tubes as well in my stereo.  After buying the quickie, I started to fantasize about building an entire tube system.  It will be a long term project if I do it.  Right now I just want to get music back in the house.  I listen to about anything except current pop or pop country.  I love the blues. I used to live 10 minutes from Severence Hall in Cleveland where the Cleveland Orchestra plays, so I know what an orchestra is supposed to sound like.  I know my current system has always had its limitations, but it never became noisey.  I never minded having it on in the background and was usually pleased when I sat down to play audiphile. 

So, just to be clear, here are my project goals:

1) Get my quickie built and get the music turned back on.
2) Listen and decide if I think going with a tube preamp as a long term solution will work for me.
3) Investigate the feasability of building an all tube stereo and well matched speakers based on my budget constraints.

Thanks again everybody. 

[Grainger49]

tyerkey,

Check your PMs.

[tbbenton]

I _love_ my econowaves (scratch built similar to pi 4) and the idea is really easy to do on a budget:
  http://audiokarma.org/forums/showthread.php?t=150939

I am official ewaver #47 on the build thread:
  http://audiokarma.org/forums/showthread.php?p=2260584#post2260584

[TonyMc]

I'm looking to build my first DIY too when the weather warms up.
I was orginally going to build a Saburo horn, but I want a bigger driver. After doing some research I discovered the Audio Nirvana Super 10. The cast version looks great and so far everything I have read has been very positive.
The only down side it sounds like is the cabinet plans that come with the drivers may not be ideal according to the driver specs.
That's OK because they look like an easy jump off point for a first timer. You can always put the driver in a better cabinet later on down the road.

[kgoss]

I am using a pair of Audio Nirvana Super 8 cast frame drivers in 2.8 Mk II cabinets that I built with plans that I got with the speakers.  I have been listening to them for over 2 years now and am very happy with the imaging, bass, and the seamless frequency response.  I have never measured the room, but I don't hear any peaks or holes which is good enough for me.  I drive them with either my S.E.X. amp or a pair of Quicksilver Horn Mono amps.  I like both amps, but I have to give the nod to the S.E.X. for its greater ability to make performers seem live in the room.  I am planning to build a pair of Bottlehead Paramount amps in the future and will use those to drive the AN speakers too.

For what its worth they have drivers with Alnico magnets available now and I'm seriously considering building a pair of the 5.6 MK II cabinets with either 10 or 12 inch Alnico drivers.  Those should sing with a pair of Parmounts too.

Ken

[TonyMc]

I am using a pair of Audio Nirvana Super 8 cast frame drivers in 2.8 Mk II cabinets that I built with plans that I got with the speakers.  I have been listening to them for over 2 years now and am very happy with the imaging, bass, and the seamless frequency response.  I have never measured the room, but I don't hear any peaks or holes which is good enough for me.  I drive them with either my S.E.X. amp or a pair of Quicksilver Horn Mono amps.  I like both amps, but I have to give the nod to the S.E.X. for its greater ability to make performers seem live in the room.  I am planning to build a pair of Bottlehead Paramount amps in the future and will use those to drive the AN speakers too.

For what its worth they have drivers with Alnico magnets available now and I'm seriously considering building a pair of the 5.6 MK II cabinets with either 10 or 12 inch Alnico drivers.  Those should sing with a pair of Parmounts too.

Ken

I was looking into the Alnico version, but not sure my untrained ears could tell the difference.
Eventually I would like to build the Stereomour and replace the Dynaco to drive these.

How do you like the build quality of the drivers? Did they take a long time to break in?

[kgoss]

In my opinion the build quality of the Audio Nirvana drivers is very good.  I don't have any experience with other full range drivers like Lowther so I can't give you any comparisons.  But the cast frame drivers have heavy and very sturdy frames and there was no problem with the cones.

The drivers do take a couple hundred hours to break in though and they will start out sounding bright.  I ran mine face to face with one speaker wired out of phase and a blanket over them using a small solid state integrated amp to break them in.  I believe that was one of the many nuggets I have gotten from Grainger's posts.

Some people think that full range drivers only work in horn cabinets, and that might be true of the others.  But in my experience, the Audio Nirvana drivers sound good in the simple bass reflex cabinets that are recommended.  For what its worth, the only thing I don't like is some of the boastful content on David's web site, but he was good to deal with and answered all my questions.

[TonyMc]

Good information. Thanks kgoss.

[Laudanum]

Just to add to what KGoss mentions.  I have a pair of Fostex full rangers in double bass reflex cabs.   It's been 10 years and I cant remember the driver models but they are either FE206 or FE207's.  They were recommended for horn cabs.  if memory serves with a different model recommended for the double bass reflex I built but when modeling the enclosure they looked like a good match.  They sound really good and they are driven by an inexpensive PP tube amp (kit) , about 7 watts if memory serves.  Efficient speakers, I dont use much volume knob before they really get loud.  Bass is down to close to 40Hz as well so for my music, mostly electric blues, they work great. 

There is quite a bit of info on the web about Fostex drivers in simple bass reflex cabs.  My DBR cab isnt much more complicated.  There are even a couple popular (maybe more) small speaker manufacturers that build and recommend some of the Fostex (and other full rangers)  in simple bass reflex cabs.

Right now Im researching whether there is a suitable Fostex or other affordable full or extended range driver than I can successfully drop into my 3.5 cubic foot vented enclosures.  They house my JBL LE8TH drivers (with Fostex tweets on L-Pads).  I am having no success finding the correct JBL re-build kits for these drivers.  This is my favorite driver/cab and I cant seem to get them fixed to original factory spec.  Very frustrating. 

[InfernoSTi]

I'm a little late to the party but wanted to add that if you ever consider OB speakers, Hawthorne Audio makes some fine drivers that are very well respected.  They are (mostly) DIY as you can imagine, and they are specifically designed for SET amps.  I know you are currently in a 40 watt amp...just saying that you MIGHT go this direction once you start to hear Bottlehead gear more...it's infectious (and other's might read this with a similar question, right?)!

All the best....

John